Amygdala functional connectivity with medial prefrontal cortex at rest predicts the positivity effect in older adults' memory.
As people get older, they tend to remember more positive than negative information. This age-by-valence interaction has been called "positivity effect." The current study addressed the hypotheses that baseline functional connectivity at rest is predictive of older adults' brain activity when learning emotional information and their positivity effect in memory. Using fMRI, we examined the relationship among resting-state functional connectivity, subsequent brain activity when learning emotional faces, and individual differences in the positivity effect (the relative tendency to remember faces expressing positive vs. negative emotions). Consistent with our hypothesis, older adults with a stronger positivity effect had increased functional coupling between amygdala and medial PFC (MPFC) during rest. In contrast, younger adults did not show the association between resting connectivity and memory positivity. A similar age-by-memory positivity interaction was also found when learning emotional faces. That is, memory positivity in older adults was associated with (a) enhanced MPFC activity when learning emotional faces and (b) increased negative functional coupling between amygdala and MPFC when learning negative faces. In contrast, memory positivity in younger adults was related to neither enhanced MPFC activity to emotional faces, nor MPFC-amygdala connectivity to negative faces. Furthermore, stronger MPFC-amygdala connectivity during rest was predictive of subsequent greater MPFC activity when learning emotional faces. Thus, emotion-memory interaction in older adults depends not only on the task-related brain activity but also on the baseline functional connectivity.


Microenvironmental independence associated with tumor progression.
Tumor-microenvironment interactions are increasingly recognized to influence tumor progression. To understand the competitive dynamics of tumor cells in diverse microenvironments, we experimentally parameterized a hybrid discrete-continuum mathematical model with phenotypic trait data from a set of related mammary cell lines with normal, transformed, or tumorigenic properties. Surprisingly, in a resource-rich microenvironment, with few limitations on proliferation or migration, transformed (but not tumorigenic) cells were most successful and outcompeted other cell types in heterogeneous tumor simulations. Conversely, constrained microenvironments with limitations on space and/or growth factors gave a selective advantage to phenotypes derived from tumorigenic cell lines. Analysis of the relative performance of each phenotype in constrained versus unconstrained microenvironments revealed that, although all cell types grew more slowly in resource-constrained microenvironments, the most aggressive cells were least affected by microenvironmental constraints. A game theory model testing the relationship between microenvironment resource availability and competitive cellular dynamics supports the concept that microenvironmental independence is an advantageous cellular trait in resource-limited microenvironments.


NOX4 Deletion in Male Mice Exacerbates the Effect of Ethanol on Trabecular Bone and Osteoblastogenesis.
Chronic alcohol consumption increases bone resorption and decreases bone formation. A major component of ethanol (EtOH) pathology in bone is the generation of excess reactive oxygen species (ROS). The ROS-generating NADPH oxidase-4 (NOX4) is proposed to drive much of the EtOH-induced suppression of bone formation. Here, 13-week-old male wild-type (WT) and NOX4-/- mice were pair fed (PF) a high-fat (35%), Lieber-DeCarli liquid diet with or without EtOH at 30% of their total calories for 12 weeks. Micro-computed tomography analysis demonstrated significant decreases in trabecular bone volume/total volume (BV/TV) percentage and cortical thickness in WT, EtOH-fed mice compared with PF controls. EtOH-fed NOX4-/- mice also displayed decreased trabecular BV/TV and trabecular number compared with PF (P < 0.05). However, NOX4-/- mice were protected against EtOH-induced decreases in cortical thickness (P < 0.05) and decreases in collagen1 and osteocalcin mRNA expression in cortical bone (P < 0.05). In WT and NOX4-/- vertebral bone, EtOH suppressed expression of Wnt signaling components that promote osteoblast maturation. A role for NOX4 in EtOH inhibition of osteoblast differentiation was further demonstrated by protection against EtOH inhibition of osteoblastogenesis in ex vivo bone marrow cultures from NOX4-/-, but not p47phox-/- mice lacking active NADPH oxidase-2. However, bone marrow cultures from NOX4-/- mice formed fewer osteoblastic colonies compared with WT cultures (P < 0.05), suggesting a role for NOX4 in the maintenance of mesenchymal progenitor cell populations. These data suggest that NOX4 deletion is partially protective against EtOH effects on osteoblast differentiation, but may predispose bone to osteogenic impairments.


Cell-cell interaction in graft rejection responses: induction of anti-allo-class I H-2 tolerance is prevented by immune responses against allo-class II H-2 antigens coexpressed on tolerogen.
The intravenous sensitization of C57BL/6 (B6) mice with class I H-2-disparate B6-C-H-2bm1 (bm1) spleen cells results in almost complete abrogation of anti-bm1 CD8+ helper (proliferative and interleukin 2-producing) T cell (Th) activities. Although an appreciable portion of CD8+ cytotoxic T lymphocyte (CTL) precursors themselves remained after this regimen, such a residual CTL activity was eliminated after the engrafting of bm1 grafts, and these grafts exhibited prolonged survival. In contrast, the intravenous sensitization with (bm1 x B6-C-H-2bm12 [bm12])F1 cells instead of bm1 cells failed to induce the prolongation of bm1 graft survival as well as bm12 and (bm1 x bm12)F1 graft survival. In the (bm1 x bm12)F1-presensitized B6 mice before as well as after the engrafting of bm1 grafts, anti-bm1 CTL responses that were comparable to or slightly stronger than those observed in unpresensitized mice were induced in the absence of anti-bm1 Th activities. bm1 graft survival was also prolonged by intravenous presensitization with a mixture of bm1 and bm12 cells but not with a mixture of bm1 and (bm1 x bm12)F1 cells. The capacity of CD4+ T cells to reject bm12 grafts was eliminated by intravenous presensitization with antigen-presenting cell (APC)-depleted bm12 spleen cells. However, intravenous presensitization with APC-depleted (bm1 x bm12)F1 cells failed to induce the prolongation of bm1 graft survival under conditions in which appreciably prolonged bm12 graft survival was induced. More surprisingly, bm1 graft survival was not prolonged even when the (bm1 x bm12)F1 cell presensitization was performed in CD4+ T cell-depleted B6 mice. This contrasted with the fact that conventional class I-disparate grafts capable of activating self Ia-restricted CD4+ as well as allo-class I-reactive CD8+ Th exhibited prolonged survival in CD4+ T cell-depleted, class I-disparate cell-presensitized mice. These results indicate that: (a) intravenous presensitization with class I- and II-disparate cells fails to reduce anti-allo-class I rejection responses that would otherwise be eliminated using only class I-disparate cells; (b) such failure is generated according to the coexpression of both classes of alloantigens on a single cell as tolerogen; and (c) allo-class II antigens coexpressed on tolerogen function to activate CD4+ as well as non-CD4+ Th leading to the generation of anti-class I effector T cell responses.


Glass-fiber self-mixing intra-arterial laser Doppler velocimetry: signal stability and feedback analysis.
We have developed a blood velocimeter based on the principle of self-mixing in a semiconductor laser diode through an optical fiber. The intensity of the light is modulated by feedback from moving scattering particles that contain the Doppler-shift frequency. Upon feedback the characteristics of the laser diode change. The threshold current decreases, and an instable region may become present above the new threshold. The amplitude of the Doppler signal turns out to be related to the difference in intensity between situations with and without feedback. This amplitude is highest just above feedback. The suppression of reflection from the glass-fiber facets is of paramount importance in the obtaining of a higher signal-to-noise ratio. Using an optical stabilization of the feedback, we optimized the performance of the laser-fiber system and the Doppler modulation depth and clarified its behavior with a suitable physical model. We also investigated the effect of the finite coherence length of the laser. We tested the efficiency of the self-mixing velocimeter in vivo with the optical glass fiber inserted in the artery with endoscopic catheters, both in upstream and in downstream blood flow conditions. For the latter we used a special side-reflecting device solution for the fiber facet to allow downstream measurements.


Sympathetic nervous system and insulin resistance: from obesity to diabetes.
As the world faces an obesity "epidemic," the mechanisms by which overweight is translated into insulin resistance, hypertension, and diabetes need to be better understood. Although the processes of transition remain uncertain, overactivity of the sympathetic nervous system appears pivotal. In obesity, there is stimulation of sympathetic outflow to the kidneys, evident in increased rates of spillover of noradrenaline into the renal veins, and to skeletal muscle vasculature, demonstrated with microneurography. The cause is unclear, but possibly involves the stimulatory action of leptin released from adipose tissue, or from within the brain, for which there is recent evidence in human obesity. The high renal sympathetic tone contributes to hypertension development by stimulating renin secretion and through promoting renal tubular reabsorption of sodium. Neurally mediated skeletal muscle vasoconstriction reduces glucose delivery and uptake in muscle. Impairment of glucose uptake by skeletal muscle is a hallmark of insulin resistance syndromes. Pharmacologic sympathetic nervous suppression within the central nervous system with imidazoline receptor-binding agents such as rilmenidine is a logical therapeutic approach for lowering blood pressure (BP) in patients with essential hypertension, in whom sympathetic activity is often increased. In addition, drugs of this class appear to have the capacity to favorably modify insulin sensitivity, which has particular relevance in the treatment of hypertensive diabetic patients. In the hypertension accompanying maturity onset obesity, with recent recommendations from advisory bodies setting lower goal BP, and with these lower targets often being reached only with combinations of antihypertensive agents, it is advisable that all drugs used in combination therapy have a favorable or at least a neutral effect on insulin resistance.


Paradental cyst of the first molar: Report of a rare case with bilateral presentation and review of the literature.
The paradental cyst is a lesion classified and recognized by World Health Organization quite recently, which is related to an inflammatory process, especially pericoronitis, involving a tooth in eruption. The aim of this article is to report a rare bilateral case of paradental cyst. An 8-year-old boy presented to the Oral Surgery Department, Dental Clinic, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Fondazione Ospedale Maggiore Policlinico, University of Milan, with the complaint of swelling over the buccal gingiva of his unerupted lower left first molar. Radiographs revealed a radiolucency involving the bifurcation and root area of teeth 36 and 46. The cysts were enucleated, maintaining the affected teeth in site; microscopic evaluation revealed a chronically inflamed cyst lined by a non-keratinized stratified squamous epithelium; the histopathology associated with macroscopic and radiographic examinations permitted the definitive diagnosis of a paradental cyst on the mandibular left and right first molars. The most recent literature shows the rarity of the paradental cyst occurring with bilateral localization. Because the paradental cyst can present variable clinical and radiographic signs, it is mandatory to correlate all clinical, radiographic, and histological data to obtain a definitive diagnosis.


A Factorial Experiment to Optimize Remotely Delivered Behavioral Treatment for Obesity: Results of the Opt-IN Study.
Intensive behavioral obesity treatments face scalability challenges, but evidence is lacking about which treatment components could be cut back without reducing weight loss. The Optimization of Remotely Delivered Intensive Lifestyle Treatment for Obesity (Opt-IN) study applied the Multiphase Optimization Strategy to develop an entirely remotely delivered, technology-supported weight-loss package to maximize the amount of weight loss attainable for ≤$500. Six-month weight loss was examined among adults (N = 562) with BMI ≥ 25 who were randomly assigned to conditions in a factorial experiment crossing five dichotomous treatment components set to either low/high (12 vs. 24 coaching calls) or off/on (primary care provider reports, text messaging, meal replacements, and buddy training). About 84.3% of participants completed the final assessment. The treatment package yielding maximum weight loss for ≤$500 included 12 coaching calls, buddy training, and primary care provider progress reports; produced average weight loss of 6.1 kg, with 57.1% losing ≥5% and 51.8% losing ≥7%; and cost $427 per person. The most expensive candidate-treatment component (24 vs. 12 coaching calls) was screened out of the optimized treatment package because it did not increase weight loss. Systematically testing each treatment component's effect on weight loss made it possible to eliminate more expensive but less impactful components, yielding an optimized, resource-efficient obesity treatment for evaluation in a randomized controlled trial.


Effect of fibrous separators on the performance of lithium-sulfur batteries.
In this paper we systematically investigated effect of separator morphology on the performance of Li-S batteries. We tested two kinds of commercially available non-woven fibrous separators made of polypropylene in conjunction with trilayer PP/PE/PP porous separator. Among the non-woven separators, the fibers of the separator of first kind are rough and more acidic than the fibers of the separator of second art, which are smooth. It was found that batteries with smooth separator demonstrate higher Coulombic efficiency, higher charging/discharging capacity and better cycling stability. We attribute better performance of batteries with smooth fibers of separators to lower acidity than that of rough fibers. We believe that negatively charged polysulfides are unable to adsorb on more acidic rough fibers and diffuse readily to lithium electrode. In contrast, polysulfides are able to adsorb on the surface of less acidic smooth fibers that reduces their polysulfides shuttle and rapid decay of battery capacity. Strategic deployment of non-woven Freudenberg and Celgard separator in combination leads to high active mass utilization, superior wettability, reduced short circuit tendency caused by dendritic growth and slower capacity decay.


Comparing functional annotation analyses with Catmap.
Ranked gene lists from microarray experiments are usually analysed by assigning significance to predefined gene categories, e.g., based on functional annotations. Tools performing such analyses are often restricted to a category score based on a cutoff in the ranked list and a significance calculation based on random gene permutations as null hypothesis. We analysed three publicly available data sets, in each of which samples were divided in two classes and genes ranked according to their correlation to class labels. We developed a program, Catmap (available for download at http://bioinfo.thep.lu.se/Catmap), to compare different scores and null hypotheses in gene category analysis, using Gene Ontology annotations for category definition. When a cutoff-based score was used, results depended strongly on the choice of cutoff, introducing an arbitrariness in the analysis. Comparing results using random gene permutations and random sample permutations, respectively, we found that the assigned significance of a category depended strongly on the choice of null hypothesis. Compared to sample label permutations, gene permutations gave much smaller p-values for large categories with many coexpressed genes. In gene category analyses of ranked gene lists, a cutoff independent score is preferable. The choice of null hypothesis is very important; random gene permutations does not work well as an approximation to sample label permutations.


A fertile future: Fertility preservation special series.
Fertility preservation is a rapidly advancing field with numerous broad applications ranging from retaining the prospect of fertility in a child with cancer to protecting an entire species from extinction. In recent years, huge strides have been made in understanding the biology of male and female reproduction in animals and humans and using this knowledge to develop strategies for fertility preservation across a range of clinical and ecological applications. This Reproduction and Fertility preservation series is composed of articles from experts on this topic and these will highlight key developments in fertility preservation and also identify the challenges that still face this exciting and relatively new field.


CALM gatekeeper training is associated with increased confidence in utilizing means reduction approaches to suicide prevention among college resident assistants.
Most suicide prevention programs focus on increasing knowledge regarding the problem of suicide, yet many fail to include information on the science and application of means reduction approaches. In an attempt to address this gap in practice, the Counseling on Access to Lethal Means (CALM) program was developed to educate clinicians on the importance of means reduction interventions. In the current study, a gatekeeper CALM training was delivered to 167 resident assistants. Confidence levels regarding suicide prevention and means reduction skills were assessed at baseline, post-training, and after a 6-week follow-up. Results were suggestive of medium to large training effects. Though there was a small decay of training effects at follow-up, the effects were durable when compared to baseline levels. Given these findings, future gatekeeper trainings should be provided more consistently to help sustain the effects and data on the implementation of CALM principles should be measured during follow-up assessments.


Human phenol sulfotransferase pharmacogenetics: STP1 gene cloning and structural characterization.
Sulfate conjugation catalysed by phenol sulfotransferase (PST) is an important pathway in the metabolism of many drugs. Two isoforms of PST have been characterized biochemically in human tissues-a thermostable (TS), or phenol-metabolizing (P) and a thermolabile (TL), or monoamine-metabolizing (M) form. Pharmacogenetic studies of TS and TL PST activities in the human blood platelet showed that the activities of these two isoforms were regulated by separate genetic polymorphisms. Subsequently, a series of TS PST cDNAs were cloned, and, based on sequence homology, those cDNAs could be classified as members of two separate subgroups, designated here as 'TS PST1' and 'TS PST2'-indicating the existence of three rather than two PST isoforms; TS PST1, TS PST2 and TL PST. The genes encoding TS PST2, STP2, and TL PST, STM, have been cloned, structurally characterized and mapped to chromosome 16-the same chromosome on which the TS PST1 gene, STP1, is localized. As a step toward molecular pharmacogenetic studies of sulfate conjugation in humans, we set out to clone and structurally characterize STP1, the remaining uncharacterized human PST gene. We found that STP1 spanned approximately 4.4 kb and contained 9 exons. The first two exons, IA and IB, were identified by performing 5'-rapid amplification of cDNA ends (RACE) with human liver cDNA as template. Exons IA and IB were noncoding and represented two different cDNA 5'-untranslated region sequences. No canonical TATA box sequences were present within the 5'-flanking regions of the gene, i.e. regions flanking exons IA and IB. Finally, use of the long polymerase chain reaction made it possible to determine that STP1 is located approximately 45 kb 5'-upstream from STP2 on the short arm of human chromosome 16. Cloning and structural characterization of STP1, when combined with knowledge of the structures of STP2 and STM, will make it possible to study the molecular basis for the genetic regulation of PST activity in human tissue.


Depression, anxiety, and stress as predictors of postconcussion-like symptoms in a non-clinical sample.
This study examined the relationship between postconcussion-like symptoms and depressive symptoms, anxiety and stress respectively. Seventy-one university students with a negative concussion history completed the Depression Anxiety Stress Scales (DASS) and the British Columbia Postconcussion Symptom Inventory (BC-PSI). A multiple regression was conducted using the three DASS subscale scores as predictors of postconcussion-like symptoms. Depressive symptoms, anxiety and stress were significantly positively correlated with postconcussion-like symptoms at the bivariate level. When these three factors were examined together 72.9% of variance in BC-PSI total scores was explained overall. Stress and depressive symptoms emerged as significant multivariate predictors explaining 15% and 3% of unique variance, respectively. Anxiety was not a significant multivariate predictor. These results suggest that stress may be a more important predictor of postconcussion-like symptoms than previously identified. Findings are interpreted in light of Iverson (2012) conceptual model of poor outcomes from mild traumatic brain injury.


Tumour microbiomes and Fusobacterium genomics in Vietnamese colorectal cancer patients.
Perturbations in the gut microbiome have been associated with colorectal cancer (CRC), with the colonic overabundance of Fusobacterium nucleatum shown as the most consistent marker. Despite its significance in the promotion of CRC, genomic studies of Fusobacterium is limited. We enrolled 43 Vietnamese CRC patients and 25 participants with non-cancerous colorectal polyps to study the colonic microbiomes and genomic diversity of Fusobacterium in this population, using a combination of 16S rRNA gene profiling, anaerobic microbiology, and whole genome analysis. Oral bacteria, including F. nucleatum and Leptotrichia, were significantly more abundant in the tumour microbiomes. We obtained 53 Fusobacterium genomes, representing 26 strains, from the saliva, tumour and non-tumour tissues of six CRC patients. Isolates from the gut belonged to diverse F. nucleatum subspecies (nucleatum, animalis, vincentii, polymorphum) and a potential new subspecies of Fusobacterium periodonticum. The Fusobacterium population within each individual was distinct and in some cases diverse, with minimal intra-clonal variation. Phylogenetic analyses showed that within four individuals, tumour-associated Fusobacterium were clonal to those isolated from non-tumour tissues. Genes encoding major virulence factors (Fap2 and RadD) showed evidence of horizontal gene transfer. Our work provides a framework to understand the genomic diversity of Fusobacterium within the CRC patients, which can be exploited for the development of CRC diagnostic and therapeutic options targeting this oncobacterium.


Colour break in reverse bicolour daffodils is associated with the presence of Narcissus mosaic virus.
Daffodils (Narcissus pseudonarcissus) are one of the world's most popular ornamentals. They also provide a scientific model for studying the carotenoid pigments responsible for their yellow and orange flower colours. In reverse bicolour daffodils, the yellow flower trumpet fades to white with age. The flowers of this type of daffodil are particularly prone to colour break whereby, upon opening, the yellow colour of the perianth is observed to be 'broken' into patches of white. This colour break symptom is characteristic of potyviral infections in other ornamentals such as tulips whose colour break is due to alterations in the presence of anthocyanins. However, reverse bicolour flowers displaying colour break show no other virus-like symptoms such as leaf mottling or plant stunting, leading some to argue that the carotenoid-based colour breaking in reverse bicolour flowers may not be caused by virus infection. Although potyviruses have been reported to cause colour break in other flower species, enzyme-linked-immunoassays with an antibody specific to the potyviral family showed that potyviruses were not responsible for the occurrence of colour break in reverse bicolour daffodils. Colour break in this type of daffodil was clearly associated with the presence of large quantities of rod-shaped viral particles of lengths 502-580 nm in tepals. Sap from flowers displaying colour break caused red necrotic lesions on Gomphrena globosa, suggesting the presence of potexvirus. Red necrotic lesions were not observed in this indicator plant when sap from reverse bicolour flowers not showing colour break was used. The reverse transcriptase polymerase reactions using degenerate primers to carla-, potex- and poty-viruses linked viral RNA with colour break and sequencing of the amplified products indicated that the potexvirus Narcissisus mosaic virus was the predominant virus associated with the occurrence of the colour break. High viral counts were associated with the reverse bicolour daffodil flowers that were displaying colour break but otherwise showed no other symptoms of infection. Narcissus mosaic virus was the virus that was clearly linked to the carotenoid-based colour break.


Fibrogenic cell phenotype modifications during remodelling of normal and pathological human liver in cultured slices.
The debate concerning the potential remodelling and/or reversibility of cirrhotic lesions and biliary fibrosis is still open. In this work, we have used the precision-cut liver slice (PCLS) model, which maintains cell-cell and cell-matrix interactions to study, by immunohistochemistry, the behaviour of the different fibrogenic cells, i.e. hepatic stellate cells (HSC) and portal fibroblasts, in cultured (for 1 week) PCLS derived from normal and fibrotic human livers. In normal liver, before and after culture, α-smooth muscle (SM) actin was present only in the vessel walls. Platelet-derived growth factor (PDGF) receptor-β was expressed before and after culture by portal fibroblasts, and appeared after culture in HSC. Before culture, CD 34 was not expressed in parenchyma, but appeared after culture in sinusoidal endothelial cells. In cirrhotic lesions, before culture, α-SM actin, PDGF receptor-β and Thy-1 were expressed in septa; after culture, α-SM actin expression disappeared but the expression of the PDGF receptor-β and Thy-1 was maintained. In cholestatic liver specimens, α-SM actin, PDGF receptor-β and Thy-1 expression, which was present before culture in enlarged portal areas, disappeared after culture, and apoptosis was detected. In the parenchyma of both cirrhotic and cholestatic livers, the expression of the PDGF receptor-β and of CD 34, which was not observed before culture, was present in HSC and sinusoidal endothelial cells, respectively, after culture. These results indicate that during remodelling of pathological tissues in cultured liver slices, the myofibroblastic cells derived from HSC or from portal fibroblasts show different behaviours, suggesting different mechanisms of activation/deactivation.


Curriculum vitae of intestinal intraepithelial T cells: their developmental and behavioral characteristics.
The alimentary tract has an epithelial layer, consisting mainly of intestinal epithelial cells (IECs), that is exposed to the exterior world through the intestinal lumen. The IEC layer contains many intestinal intraepithelial T cells (IELs), and the total number of IELs constitutes the largest population in the peripheral T-cell pool. Virtually all gammadelta-IELs and many alphabeta-IELs in the mouse small intestine are known to express CD8 alpha alpha homodimers. A wide range of evidence that supports extrathymic development of these CD8 alpha alpha(+) IELs has been collected. In addition, while several studies identified cells with precursor T-cell phenotypes within the gut epithelium, how these precursors, which are dispersed along the length of the intestine, develop into gammadelta-IELs and/or alphabeta-IELs has not been clarified. The identification of lymphoid cell aggregations named 'cryptopatches' (CPs) in the intestinal crypt lamina propria of mice as sites rich in T-cell precursors in 1996 by our research group, however, provided evidence for a central site, whereby precursor IELs could give rise to T-cell receptor-bearing IELs. In this review, we discuss the development of IELs in the intestinal mucosa and examine the possibility that CPs serve as a production site of extrathymic IELs.


Dual functions of interferon regulatory factors 7C in Epstein-Barr virus-mediated transformation of human B lymphocytes.
Epstein-Barr virus (EBV) infection is associated with several human malignancies. Interferon (IFN) regulatory factor 7 (IRF-7) has several splicing variants, and at least the major splicing variant (IRF-7A) has oncogenic potential and is associated with EBV transformation processes. IRF-7C is an alternative splicing variant with only the DNA-binding domain of IRF-7. Whether IRF-7C is present under physiological conditions and its functions in viral transformation are unknown. In this report, we prove the existence of IRF-7C protein and RNA in certain cells under physiological conditions, and find that high levels of IRF-7C are associated with EBV transformation of human primary B cells in vitro as well as EBV type III latency. EBV latent membrane protein 1 (LMP-1) stimulates IRF-7C expression in B lymphocytes. IRF-7C has oncogenic potential in rodent cells and partially restores the growth properties of EBV-transformed cells under a growth-inhibition condition. A tumor array experiment has identified six primary tumor specimens with high levels of IRF-7C protein--all of them are lymphomas. Furthermore, we show that the expression of IRF-7C is apparently closely associated with other IRF-7 splicing variants. IRF-7C inhibits the function of IRF-7 in transcriptional regulation of IFN genes. These data suggest that EBV may use splicing variants of IRF-7 for its transformation process in two strategies: to use oncogenic properties of various IRF-7 splicing variants, but use one of its splicing variants (IRF-7C) to block the IFN-induction function of IRF-7 that is detrimental for viral transformation. The work provides a novel relation of host/virus interactions, and has expanded our knowledge about IRFs in EBV transformation.


Zika Virus Infection at Different Pregnancy Stages: Anatomopathological Findings, Target Cells and Viral Persistence in Placental Tissues.
Zika virus (ZIKV) infection in humans has been associated with congenital malformations and other neurological disorders, such as Guillain-Barré syndrome. The mechanism(s) of ZIKV intrauterine transmission, the cell types involved, the most vulnerable period of pregnancy for severe outcomes from infection and other physiopathological aspects are not completely elucidated. In this study, we analyzed placental samples obtained at the time of delivery from a group of 24 women diagnosed with ZIKV infection during the first, second or third trimesters of pregnancy. Villous immaturity was the main histological finding in the placental tissues, although placentas without alterations were also frequently observed. Significant enhancement of the number of syncytial sprouts was observed in the placentas of women infected during the third trimester, indicating the development of placental abnormalities after ZIKV infection. Hyperplasia of Hofbauer cells (HCs) was also observed in these third-trimester placental tissues, and remarkably, HCs were the only ZIKV-positive fetal cells found in the placentas studied that persisted until birth, as revealed by immunohistochemical (IHC) analysis. Thirty-three percent of women infected during pregnancy delivered infants with congenital abnormalities, although no pattern correlating the gestational stage at infection, the IHC positivity of HCs in placental tissues and the presence of congenital malformations at birth was observed. Placental tissue analysis enabled us to confirm maternal ZIKV infection in cases where serum from the acute infection phase was not available, which reinforces the importance of this technique in identifying possible causal factors of birth defects. The results we observed in the samples from naturally infected pregnant women may contribute to the understanding of some aspects of the pathophysiology of ZIKV.


A newly recognized congenital myasthenic syndrome attributed to a prolonged open time of the acetylcholine-induced ion channel.
Five familial cases (in two families) and one sporadic case of a new congenital myasthenic syndrome were investigated. Symptoms arise in infancy or later life. Typically, one finds selective involvement of cervical, scapular, and finger extensor muscles, ophthalmoparesis, and variable involvement of other muscles. There is a repetitive muscle action potential to single nerve stimulus in all muscles and a decremental response at 2 to 3 Hz stimulation in clinical affected muscles. Microelectrode studies reveal markedly prolonged end-plate potential (epp), miniature end-plate potential (mepp), and miniature end-plate current; normal quantum content of the epp; and a smaller than normal or low-normal mepp amplitude. Light microscopy demonstrates predominance of type I fibers, small groups of atrophic fibers, tubular aggregates and vacuoles near end-plates, abnormal end-plate configuration, and nonspecific myopathic changes. Abundant acetylcholinesterase activity is present at all end-plates, and the activity and kinetic properties of this enzyme in muscle are normal. Calcium accumulated at the end-plate in one patient. Quantitative electron microscopy shows decrease in the size of nerve terminals, increase in the density of synaptic vesicles, and reduction in the length of postsynaptic membranes. There is focal degeneration of junctional folds with corresponding loss of acetylcholine receptor, most marked in cases with the lowest mepp amplitude. There are no immune complexes at the end-plate. Fiber regions near end-plates display dilation, proliferation, and degeneration of the sarcoplasmic reticulum; nuclear, mitochondrial, and myofibrillar degeneration; and vacuoles resembling those found in periodic paralysis. A prolonged open time of the acetylcholine-induced ion channel is considered to be the basic abnormality and may account for the physiological, morphological, and clinical alterations.


T regulatory cells: aid or hindrance in the clearance of disease?
CD4+ CD25+ T regulatory cells (Tregs) are classified as a subset of T cells whose role is the suppression and regulation of immune responses to self and non-self. Since their discovery in the early 1970s, the role of CD4+ CD25+ Tregs in both autoimmune and infectious disease has continued to expand. This review examines the recent advances on the role CD4+ CD25+ Tregs may be playing in various diseases regarding progression or protection. In addition, advances made in the purification and manipulation of CD4+ CD25+ Tregs using new cell markers, techniques and antibodies are discussed. Ultimately, an overall understanding of the exact mechanism which CD4+ CD25+ Tregs implement during disease progression will enhance our ability to manipulate CD4+ CD25+ Tregs in a clinically beneficial manner.


Rivastigmine for vascular cognitive impairment.
Vascular dementia represents the second most common type of dementia after Alzheimer's disease. In older patients, in particular, the combination of vascular dementia and Alzheimer's disease is common, and is referred to as mixed dementia. The classification of vascular dementia broadly follows three clinico-pathological processes: multi-infarct dementia, single strategic infarct dementia and subcortical dementia. Not all victims fulfil strict criteria for dementia and may be significantly cognitively impaired without memory loss, when the term vascular cognitive impairment (VCI) is more useful. Currently, no established standard treatment for VCI exists. Reductions in acetylcholine and acetyltransferase activity are common to both Alzheimer's disease and VCI, raising the possibility that cholinesterase inhibitors - such as rivastigmine - which are beneficial in Alzheimer's disease, may also be beneficial for VCI. To assess the efficacy of rivastigmine compared with placebo in the treatment of people with vascular cognitive impairment (VCI), vascular dementia or mixed dementia. We searched ALOIS (the Cochrane Dementia and Cognitive Improvement Group's Specialized Register) on 12 February 2013 using the terms: rivastigmine, exelon, "SDZ ENA 713". ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases (The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsycINFO, LILACS), numerous trial registries and grey literature sources. All unconfounded randomized double-blind trials comparing rivastigmine with placebo in the treatment of people with VCI, vascular dementia or mixed dementia were eligible for inclusion. Two reviewers extracted and assessed data independently, and agreement was reached after discussion. They noted results concerning adverse effects. Three trials, with a total of 800 participants, were identified for inclusion. The participants in one trial did not have dementia, while the other two studies included participants with dementia of different severities. The dose of rivastigmine was different in each study. No pooling of study results was attempted because of these differences between the studies.One trial included 40 participants with subcortical vascular dementia (age range 40 to 90 years) with a mean mini-mental state examination (MMSE) score of 13.0 and 13.4 in the rivastigmine and placebo arms, respectively. Treatment over 26 weeks was limited to 3 mg rivastigmine twice daily, or placebo. No significant difference was found on any outcome measure relevant to cognition, neuropsychiatric symptoms, function or global rating, or in the number of withdrawals before the end of treatment.Another trial included 710 participants with vascular dementia, including subcortical and cortical forms (age range 50 to 85 years). Over 24 weeks, a mean dose of rivastigmine of 9.4 mg/day was achieved versus placebo. Baseline MMSE was identical for both groups, at 19.1. Statistically significant advantage in cognitive response (but not with global impression of change or non-cognitive measures) was seen with rivastigmine treatment at 24 weeks (MMSE change from baseline MD 0.6, 95% CI 0.11 to 1.09, P value 0.02; Vascular Dementia Assessment Scale (VaDAS) change from baseline MD -1.3, 95% CI-2.62 to 0.02, P value 0.05 ). Significantly higher rates of vomiting, nausea, diarrhoea and anorexia and withdrawals from treatment were noted in the participants randomized to rivastigmine compared with placebo (withdrawals rivastigmine 90/365, placebo 48/345, OR 2.02, 95% CI 1.38 to 2.98) (withdrawals due to an adverse event rivastigmine 49/365, placebo 19/345, OR 2.66, 95% CI 1.53 to 4.62, P value 0.0005).The third study included 50 participants (age range 48 to 84 years) with mean MMSE scores of 23.7 and 23.9 in the rivastigmine and placebo arms, respectively. Over a 24-week period, participants labelled as having cognitive impairment but no dementia (CIND) following ischaemic stroke were given up to 4.5 mg rivastigmine twice daily, or placebo. Primary and secondary outcome measures showed no statistically significant difference when considering neurocognitive abilities, function, neuropsychiatric symptoms and global performance. One participant in the rivastigmine group and two in the placebo group discontinued their medication because of an adverse effect. There is some evidence of benefit of rivastigmine in VCI from trial data from three studies. However, this conclusion is based on one large study. Rivastigmine is capable of inducing side effects that lead to withdrawal in a significant proportion of patients.


TAP, HLA-DQB1, and HLA-DRB1 polymorphism in Colombian patients with primary Sjögren's syndrome.
Although primary Sjögren's syndrome (pSS) has a worldwide distribution, little data is available on pSS immunogenetics in non-white populations. Thus, we investigated the influence of transporters associated with antigen processing (TAP), human leukocyte antigen (HLA)-DQB1, and HLA-DRB1 gene polymorphism in mestizo Colombian patients with pSS. In this cross-sectional and controlled study, all patients met the European criteria for classification of pSS. TAP and HLA typing was performed by polymerase chain reaction techniques. Genetic data analysis was performed to detect deviations from the expected Hardy-Weinberg (H-W) proportions and to determine the presence of population stratification or subdivision and the existence of linkage disequilibrium between pairs of loci. Seventy-three Colombian patients with pSS (95% women) and 76 healthy controls were studied. Although significant associations were not observed between TAP or HLA polymorphism and disease, strong linkage disequilibrium among the loci TAP2 and DQB1 was found in patients. Deviations from the H-W expected value were found in the DQB1 locus of patients (P =.02). HLA-DRB1*0301-DQB1*0201 haplotype was associated with more severe histopathologic disease (odds ratio [OR], 15.5; 95% confidence interval [CI], 1.9-129; P =.001) and the presence of anti-Ro (OR, 3.8; 95% CI, 1-15; P =.04) and anti-La antibodies (OR, 4.3; 95% CI, 1.3-14; P =.01). The data show genetic evidence suggesting that, in Colombians, a region immersed or in the vicinity in the HLA class II system is strongly associated with a predisposition to acquire pSS, which is probably located between the TAP2 and HLA-DQB1 locus. Our results confirm that the HLA-DRB1*0301-DQB1*0201 haplotype participates in the pathogenesis of pSS.


Specificity of sprint and agility training methods.
The purpose of this study was to determine if straight sprint training transferred to agility performance tests that involved various change-of-direction complexities and if agility training transferred to straight sprinting speed. Thirty-six males were tested on a 30-m straight sprint and 6 agility tests with 2-5 changes of direction at various angles. The subjects participated in 2 training sessions per week for 6 weeks using 20-40-m straight sprints (speed) or 20-40-m change-of-direction sprints (3-5 changes of 100 degrees) (agility). After the training period, the subjects were retested, and the speed training resulted in significant improvements (p < 0.05) in straight sprinting speed but limited gains in the agility tests. Generally, the more complex the agility task, the less the transfer from the speed training to the agility task. Conversely, the agility training resulted in significant improvements in the change-of-direction tests (p < 0.05) but no significant improvement (p > 0.05) in straight sprint performance. We concluded that straight speed and agility training methods are specific and produce limited transfer to the other. These findings have implications for the design of speed and agility training and testing protocols.


Functional cytochrome P4503A isoforms in human embryonic tissues: expression during organogenesis.
Expression of functional cytochrome P450 (CYP) isoforms in human embryonic tissues was explored during organogenesis (days 50-60 of gestation) with substrate probes, inhibitor probes, and immunoprobes and by reverse transcription-polymerase chain reaction (PCR), cloning, and sequencing. Evidence was obtained for the presence of relatively high levels of one or more functional CYP3A isoforms in embryonic livers. This was manifested as relatively extensive hydroxylation of (R)-warfarin at carbon 10 and as triacetyloleandomycin-inhibited O-debenzylation of benzyloxyresorufin when human embryonic hepatic microsomal fractions were used as enzyme sources. Immunoblots with anti-CYP3A4 antibody exhibited a strong signal in embryonic hepatic tissues but, in contrast, indicated very low or negligible CYP3A levels in human embryonic lung, kidney, heart, adrenal, and brain tissues. To explore expression of individual members of the CYP3A subfamily in human embryonic hepatic tissues at this early gestational stage, CYP3A cDNA was generated by reverse transcription, amplified by PCR, cloned, and sequenced. Oligonucleotide primers used for PCR were designed to flank target sequences unique to CYP3A but also common to all human CYP3A subfamily members for which GenBank nucleotide sequence information was available (CYP3A3, CYP3A4, CYP3A5, CYP3A5P, and CYP3A7). Sequencing data indicated that plasmids in 58 of 59 recombinant positive colonies contained an insert with a sequence identical to that present in CYP3A7 cDNA and the plasmid of only one colony contained an insert with a sequence identical to that present in CYP3A5 cDNA. No evidence was found for expression of CYP3A3 or CYP3A4. Thus, during organogenesis, human embryonic hepatic tissues express primarily CYP3A7 and are capable of significant CYP3A7-catalyzed xenobiotic monooxygenation during this very early stage of gestation.


Polyethylene Glycol-Based Synthetic Hydrogel Sealant for Closing Vitrectomy Wounds: An In Vivo and Histological Study.
We conducted an in vivo study using Dutch pigmented rabbit eyes to test the usefulness of polyethylene glycol (PEG) sealant for the closure of sutureless sclerotomies in microincisional vitrectomy surgery (MIVS). Three-port, 23-gauge vitrectomy was performed on rabbit eyes. After air leakage was confirmed by the application of 0.625% povidone-iodine at the sclerotomy site, PEG sealant was subconjunctivally injected using a 27-gauge needle through conjunctival incisions to cover the sclerotomy wounds, following which it was polymerized by the application of xenon light for 60 seconds. Ophthalmological examinations and intraocular pressure measurements were conducted the day before and 1, 3, 5, and 7 days after surgery. The eyes were enucleated for histological evaluation 7 days after surgery. PEG sealant was rapidly polymerized by the application of xenon light after subconjunctival injection, and it firmly sealed the sclerotomies without air leakage, as confirmed by povidone-iodine dropping, in all cases. Conjunctival and scleral wounds closed with PEG sealant were successfully attached and remained intact till the end of the follow-up period. There was no sign of postoperative hypotony or infection in any eye, and no adverse effects of PEG sealant were found. In histological examination, linear scar formation and eosinophilic staining of collagen fibers were observed at the sclerotomy sites, while the sclerotomy tunnels appeared tightly closed. PEG sealant can be useful for the closure of sutureless 23-gauge vitrectomy incisions in rabbits. The PEG sealant may become an effective option for closing vitrectomy incisions including pediatric cases.


Preclinical development of the novel Chk1 inhibitor SCH900776 in combination with DNA-damaging agents and antimetabolites.
Many anticancer agents damage DNA and arrest cell-cycle progression primarily in S or G(2) phase of the cell cycle. Previous studies with the topoisomerase I inhibitor SN38 have shown the efficacy of the Chk1 inhibitor UCN-01 to overcome this arrest and induce mitotic catastrophe. UCN-01 was limited in clinical trials by unfavorable pharmacokinetics. SCH900776 is a novel and more selective Chk1 inhibitor that potently inhibits Chk1 and abrogates cell-cycle arrest induced by SN38. Like UCN-01, abrogation of SN38-induced arrest enhances the rate of cell death but does not increase overall cell death. In contrast, SCH900776 reduced the growth-inhibitory concentration of hydroxyurea by 20- to 70-fold. A similar magnitude of sensitization was observed with cytarabine. A 5- to 10-fold sensitization occurred with gemcitabine, but no sensitization occurred with cisplatin, 5-fluorouracil, or 6-thioguanine. Sensitization occurred at hydroxyurea concentrations that marginally slowed DNA replication without apparent activation of Chk1, but this led to dependence on Chk1 that increased with time. For example, when added 18 hours after hydroxyurea, SCH900776 induced DNA double-strand breaks consistent with rapid collapse of replication forks. In addition, some cell lines were highly sensitive to SCH900776 alone, and these cells required lower concentrations of SCH900776 to sensitize them to hydroxyurea. We conclude that some tumors may be very sensitive to the combination of SCH900776 and hydroxyurea. Delayed administration of SCH900776 may be more effective than concurrent treatment. SCH900776 is currently in phase I clinical trials, and these results provide the rationale and schedule for future clinical trials.


A new role for SOCS in insulin action. Suppressor of cytokine signaling.
Suppressor of cytokine signaling (SOCS) family proteins were initially identified as inhibiting cytokine signaling pathways through a negative feedback loop involving the inhibition of Janus kinase activity. More recent data suggest that SOCS proteins may also modulate signaling mediated through receptor tyrosine kinases. Krebs and Hilton discuss research implicating SOCS-1 and SOCS-3 as inhibitors of insulin receptor-mediated and insulin-like growth factor-1 receptor-mediated signaling pathways, as well as the increasing evidence that SOCS proteins may act in part by participating in a ubiquitin ligase complex to promote the degradation of target proteins.


Long-term results of esophageal transection and devascularization procedure in treatment of esophageal variceal bleeding.
Fifty-three patients with bleeding esophageal varices received a non-shunting operation--esophageal transection and devascularization of the proximal stomach with splenectomy--from March 1977 to October 1986. The ages of these patients ranged from 26 to 69 years with a mean of 49.70 +/- 10.03 years (+/- SD). Thirty-six patients were male and 17 were female. The pathology of the liver was post-necrotic liver cirrhosis in 39 cases, alcoholic liver cirrhosis in seven cases, liver cirrhosis with hepatocellular carcinoma in six cases and non-cirrhotic in one case. The operative mortality was 26.4% (14/53); major causes of operative death were due to liver failure (six cases) and recurrent bleeding (five cases). The operative mortality was 10% in Child's Class A, 37.5% in Class B, and 73% in Class C (p < 0.05 by Fisher's exact test). The operative mortality was 18.5% in the elective group and 40% in the emergent group, but the difference was not statistically significant. The absolute overall five-year survival rate was 61.1%, but the expected 10-year survival was only 46.4%. The major causes of death during long-term follow-up were liver failure (nine cases) and recurrent bleeding (seven cases). The incidence of recurrent bleeding of esophageal varices was 44.4% in long-term follow-up. Two patients developed hepatocellular carcinoma 22 and 37 months after their operations; this incidence was much lower than that of our previous report.(ABSTRACT TRUNCATED AT 250 WORDS)


Immunohistochemical detection of factor VIII/von Willebrand factor in hyperplastic endothelial cells in glioblastoma multiforme and mixed glioma-sarcoma.
The sarcomatous components of most glioma-sarcomas are thought to arise from the neoplastic transformation of hyperplastic endothelial and adventitial vascular cells in a preexisting glioblastoma multiforme. The expression of factor VIII/von Willebrand factor (FVIII/vWF), a marker for endothelial cells, and of glial fibrillary acidic protein (GFAP), a marker for glial cells, was examined in 10 glioblastomas and seven mixed glioma-sarcomas using the peroxidase-antiperoxidase immunohistochemical technique. Hyperplasia of small blood vessels was observed in all 10 glioblastomas; in five, the vascular proliferation had resulted in the formation of prominent glomeruloid structures. FVIII/vWF was detected in the endothelial cells in these vascular structures, but not in the adventitial cells. In the mixed glioma-sarcomas. FVIII/vWF was detected only in endothelial cells; there was no staining for FVIII/vWF in the neoplastic mesenchymal cells. The gliomatous components of the mixed tumors stained intensely for GFAP. These observations indicate that both endothelial and nonendothelial cell types contribute to the small vessel hyperplasia in glioblastomas, and that the sarcomatous components of mixed glioma-sarcomas are derived from either non-endothelial cells or endothelial cells that have undergone antigenic loss following transformation.


The Use of Defined Microbial Communities To Model Host-Microbe Interactions in the Human Gut.
The human intestinal ecosystem is characterized by a complex interplay between different microorganisms and the host. The high variation within the human population further complicates the quest toward an adequate understanding of this complex system that is so relevant to human health and well-being. To study host-microbe interactions, defined synthetic bacterial communities have been introduced in gnotobiotic animals or in sophisticated in vitro cell models. This review reinforces that our limited understanding has often hampered the appropriate design of defined communities that represent the human gut microbiota. On top of this, some communities have been applied to in vivo models that differ appreciably from the human host. In this review, the advantages and disadvantages of using defined microbial communities are outlined, and suggestions for future improvement of host-microbe interaction models are provided. With respect to the host, technological advances, such as the development of a gut-on-a-chip system and intestinal organoids, may contribute to more-accurate in vitro models of the human host. With respect to the microbiota, due to the increasing availability of representative cultured isolates and their genomic sequences, our understanding and controllability of the human gut "core microbiota" are likely to increase. Taken together, these advancements could further unravel the molecular mechanisms underlying the human gut microbiota superorganism. Such a gain of insight would provide a solid basis for the improvement of pre-, pro-, and synbiotics as well as the development of new therapeutic microbes.


Measuring Health Literacy in General Populations: Primary Findings from the HLS-EU Consortium's Health Literacy Assessment Effort.
This chapter is concerned with the difference of measuring health literacy of general population for purposes of public health as differentiated from measuring personal health literacy of individuals within health care services. The evolution of concept, measurement and empirical research of health literacy in the last decades is discussed, and the position of measuring comprehensive health literacy in general populations, especially by the European Health Literacy Survey (HLS-EU) study, is defined. Main features of the HLS-EU conceptual and logic model, definition, instruments and study design are described. General results of the HLS-EU study are presented on the distribution of health literacy, its determinants and health related consequences, for the eight involved European countries as well as the total sample. These results principally confirm findings of earlier studies with somewhat different instruments and other kinds of samples, but also demonstrate considerable differences in distributions of health literacy and its relationships with relevant variables among and between the eight countries in a standardized comparative international study. Follow-up studies based on the original HLS-EU study are mapped. In addition, the factors for the relative easy and widespread use of the instrument and research methodology by similar studies in other countries in Europe and Asia are discussed. This chapter closes with an outlook on the challenges of further developments and take-ups.


Physicochemical surface properties and phagocytosis by polymorphonuclear leucocytes of different serogroups of Salmonella.
Salmonella isolates belonging to different serogroups have been analysed with respect to physicochemical surface properties and interaction with human polymorphonuclear granulocytes (PMNs). Most (22/34) recent isolates of the different serotypes showed hydrophilic surface properties and little if any negative charge accompanied by resistance to phagocytosis by PMN similar to the old laboratory S strains Salmonella typhimurium 395MS and Salmonella minnesota S99 (main group). However, all isolates belonging to the serogroups C1 (5 isolates), E4 (2), O43 (1), and one out of three E1 isolates (C1/E4 group) differed from the main group. In aqueous biphasic partition in dextran-polyethyleneglycol (PEG) systems the bacteria in the main group accumulated in the PEG-rich phase to 55-97%, those in the C1/E4 group to less than 10%, and R-mutants only to 1-2%. The bacteria in the C1/E4 group displayed a negative surface charge and a susceptibility to phagocytosis by PMNs that were greater than those for strains in the main group but much lower than those shown by the R-mutants. Bacteria belonging to serogroup C1 also displayed a significant susceptibility to hydrophobic interaction. The results are discussed in relation to the pathogenicity of salmonella.


Clonal selection, clonal senescence, and clonal succession: the evolution of the T cell response to infection with a persistent virus.
We have analyzed the CD8(+) T cell response to EBV and find that a larger primary burst size is associated with proportionally greater decay during the development of memory. Consequently, immunodominance and clonal dominance are less marked in memory than primary responses. An intuitive interpretation of this finding is that there is a limit to the number of cell divisions a T cell clone can undergo, and that the progeny of clones that have expanded massively during a primary immune response are more prone to die as a result of senescence. To test this hypothesis, we have derived a mathematical model of the response of different T cell clones of varying avidity for Ag in the primary and persistent phases of viral infection. When cellular survival and replication are linked to T cell avidity for Ag and Ag dose, then high-avidity T cells dominate both the primary and secondary responses. We then incorporated a limit in the number of cell divisions of individual T cell clones to test whether such a constraint could reproduce the observed association between cell division number and alterations in the contribution of clones to the response to persistent infection. Comparison of the model output with the experimental results obtained from primary and persistent EBV infection suggests that there is indeed a role for cellular senescence in shaping the immune response to persistent infection.


Pathogenicity and a TaqMan Real-Time PCR for Specific Detection of Pantoea allii, a Bacterial Pathogen of Onions.
Bacterial diseases of onion are reported to cause significant economic losses. Pantoea allii Brady, one of the pathogens causing the center rot on onions, has not yet been reported in Canada. We report the pathogenicity of P. allii on commercially available Canadian green onions (scallions). All P. allii-inoculated plants, irrespective of the inoculum concentration, exhibited typical leaf chlorotic discoloration on green onion leaves, which can reduce their marketability. Reisolation of P. allii from infected scallion tissues and reidentification by sequencing and phylogenetic analyses of the leuS gene suggest that the pathogen can survive in infected tissues 21 days after inoculation. This is the first report of P. allii as a potential pathogen of green onions. This study also reports the development and validation of a TaqMan real-time PCR assay targeting the leuS gene for reliable detection of P. allii in pure cultures and in planta. A 642-bp leuS gene fragment was targeted because it showed high nucleotide diversity and positively correlated with genome-based average nucleotide identity with respect to percent similarity index and identity of Pantoea species. The assay specificity was validated using 61 bacterial and fungal strains. Under optimal conditions, the selected primers and FAM-labeled TaqMan probe were specific for the detection of nine reference P. allii strains by real-time PCR. The 52 strains of other Pantoea spp. (n = 25), non-Pantoea spp. (n = 20), and fungi/oomycetes (n = 7) tested negative (no detectable fluorescence). Onion tissues spiked with P. allii, naturally infested onion bulbs, greenhouse infected green onion leaf samples, as well as an interlaboratory blind test were used to validate the assay specificity. The sensitivities of a 1-pg DNA concentration and 30 CFU are comparable to previously reported real-time PCR assays of other bacterial pathogens. The TaqMan real-time PCR assay developed in this study will facilitate reliable detection of P. allii and could be a useful tool for screening onion imports or exports for the presence of this pathogen.


Expression and regulation of human neutrophil-derived macrophage inflammatory protein 1 alpha.
Neutrophil (polymorphonuclear leukocyte [PMN]) sequestration is one of the histologic hallmarks of an acute inflammatory response. During the natural evolution of an inflammatory response, PMNs are often replaced by mononuclear cells. This shift in the elicitation of specific leukocyte populations usually occurs as the inflammatory lesion enters either the repair/resolution stage or progresses to a chronic inflammation. To elucidate a potential mechanism for the temporal change from predominantly PMN recruitment to the presence of monocytes, we postulated that PMNs could be a rich source of monocyte chemotactic factors. In our studies, we have identified a dose-dependent induction of monocyte chemotactic activity by PMNs treated with lipopolysaccharide (LPS; 1-100 ng/ml). Interestingly, this monocyte chemotactic activity was significantly attenuated in the presence of neutralizing anti-human macrophage inflammatory protein 1 alpha (MIP-1 alpha) antibodies. Moreover, immunolocalization studies demonstrated the expression of MIP-1 alpha by stimulated PMNs. These findings showed that a significant amount of PMN-derived monocyte chemotactic activity was attributable to MIP-1 alpha. Subsequent characterization of MIP-1 alpha steady-state mRNA and antigen expression demonstrated both a dose- and time-dependent production by LPS-treated PMNs. Granulocyte/macrophage colony-stimulating factor (GM-CSF), a potent PMN activator, failed to induce the expression of MIP-1 alpha over a wide range of concentrations. However, PMNs stimulated in the presence of both LPS and GM-CSF resulted in a synergistic expression pattern for MIP-1 alpha. PMNs stimulated in the presence of both GM-CSF and LPS demonstrated an enhanced and prolonged expression for both MIP-1 alpha mRNA and antigen, as compared with LPS alone. Messenger RNA stabilization analyses demonstrated that MIP-1 alpha mRNA isolated from PMNs stimulated in the presence of GM-CSF and LPS had a prolonged mRNA t1/2, as compared with LPS alone. These findings support the notion that PMNs are capable of producing MIP-1 alpha in the presence of LPS, and that GM-CSF can influence this production through prolongation of MIP-1 alpha mRNA t1/2. The production of PMN-derived MIP-1 alpha, in association with the expression of appropriate adhesion molecules at a site of inflammation, may be one of the central events that contributes to the temporal shift from predominantly PMNs to monocytes during the evolution of inflammation.


Leptin regulates the pro-inflammatory response in human epidermal keratinocytes.
The role of leptin in cutaneous wound healing process has been suggested in genetically obese mouse studies. However, the molecular and cellular effects of leptin on human epidermal keratinocytes are still unclear. In this study, the whole-genome-scale microarray analysis was performed to elucidate the effect of leptin on epidermal keratinocyte functions. In the leptin-treated normal human keratinocytes (NHKs), we identified the 151 upregulated and 53 downregulated differentially expressed genes (DEGs). The gene ontology (GO) enrichment analysis with the leptin-induced DEGs suggests that leptin regulates NHKs to promote pro-inflammatory responses, extracellular matrix organization, and angiogenesis. Among the DEGs, the protein expression of IL-8, MMP-1, fibronectin, and S100A7, which play roles in which is important in the regulation of cutaneous inflammation, was confirmed in the leptin-treated NHKs. The upregulation of the leptin-induced proteins is mainly regulated by the STAT3 signaling pathway in NHKs. Among the downregulated DEGs, the protein expression of nucleosome assembly-associated centromere protein A (CENPA) and CENPM was confirmed in the leptin-treated NHKs. However, the expression of CENPA and CENPM was not coupled with those of other chromosome passenger complex like Aurora A kinase, INCENP, and survivin. In cell growth kinetics analysis, leptin had no significant effect on the cell growth curves of NHKs in the normal growth factor-enriched condition. Therefore, leptin-dependent downregulation of CENPA and CENPM in NHKs may not be directly associated with mitotic regulation during inflammation.


Population heterogeneity in Methylobacterium extorquens AM1.
Heterogeneity of cells within exponentially growing populations was addressed in a bacterium, the facultative methylotroph Methylobacterium extorquens AM1. A transcriptional fusion between a well-characterized methanol-inducible promoter (P(mxaF)) and gfp(uv) was used with flow cytometry to analyse the distribution of gene expression in populations grown on either succinate or methanol, correlated with forward scatter as a measure of cell size. These cell populations were found to consist of three major subpopulations defined by cells that were actively growing and dividing, newly divided, and non-dividing. Through the use of flow cytometry, it was demonstrated that a significant percentage of the total population did not respond to carbon shift. In addition, these experiments demonstrated that a small subset of the total population was significantly brighter than the rest of the population and dominated fluorimetry data. These results were corroborated with a continuous flow-through system and laser scanning microscopy, confirming that subpopulations, not discernible in the population average, dominate population response. These results demonstrate that the combination of flow cytometry and microscopic single-cell analysis can be effectively used to determine the dynamics of subpopulations in population response. In addition, they support the concept that physiological diversity in isogenic populations can poise some proportion of the population to respond appropriately to changing conditions.


Persistent activation of ERK contributes to glutamate-induced oxidative toxicity in a neuronal cell line and primary cortical neuron cultures.
Oxidative stress can trigger neuronal cell death and has been implicated in several chronic neurological diseases and in acute neurological injury. Oxidative toxicity can be induced by glutamate treatment in cells that lack ionotrophic glutamate receptors, such as the immortalized HT22 hippocampal cell line and immature primary cortical neurons. Previously, we found that neuroprotective effects of geldanamycin, a benzoquinone ansamycin, in HT22 cells were associated with a down-regulation of c-Raf-1, an upstream activator of the extracellular signal-regulated protein kinases (ERKs). ERK activation, although often attributed strictly to neuronal cell survival and proliferation, can also be associated with neuronal cell death that occurs in response to specific insults. In this report we show that delayed and persistent activation of ERKs is associated with glutamate-induced oxidative toxicity in HT22 cells and immature primary cortical neuron cultures. Furthermore, we find that U0126, a specific inhibitor of the ERK-activating kinase, MEK-1/2, protects both HT22 cells and immature primary cortical neuron cultures from glutamate toxicity. Glutamate-induced ERK activation requires the production of specific arachidonic acid metabolites and appears to be downstream of a burst of reactive oxygen species (ROS) accumulation characteristic of oxidative stress in HT22 cells. However, inhibition of ERK activation reduces glutamate-induced intracellular Ca(2+) accumulation. We hypothesize that the precise kinetics and duration of ERK activation may determine whether downstream targets are mobilized to enhance neuronal cell survival or ensure cellular demise.


Capturing multiple-type interactions into practical predictors of type replacement following human papillomavirus vaccination.
Current HPV vaccines target a subset of the oncogenic human papillomavirus (HPV) types. If HPV types compete during infection, vaccination may trigger replacement by the non-targeted types. Existing approaches to assess the risk of type replacement have focused on detecting competitive interactions between pairs of vaccine and non-vaccine types. However, methods to translate any inferred pairwise interactions into predictors of replacement have been lacking. In this paper, we develop practical predictors of type replacement in a multi-type setting, readily estimable from pre-vaccination longitudinal or cross-sectional prevalence data. The predictors we propose for replacement by individual non-targeted types take the form of weighted cross-hazard ratios of acquisition versus clearance, or aggregate odds ratios of coinfection with the vaccine types. We elucidate how the hazard-based predictors incorporate potentially heterogeneous direct and indirect type interactions by appropriately weighting type-specific hazards and show when they are equivalent to the odds-based predictors. Additionally, pooling type-specific predictors proves to be useful for predicting increase in the overall non-vaccine-type prevalence. Using simulations, we demonstrate good performance of the predictors under different interaction structures. We discuss potential applications and limitations of the proposed methodology in predicting type replacement, as compared to existing approaches. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.


Delivery by Trypanosoma cruzi of proteins into the MHC class I antigen processing and presentation pathway.
Class I MHC-restricted T cell responses have been shown to be critical for the development of immune resistance to Trypanosoma cruzi in mice. However, to date, no antigenic targets of this anti-parasite response have been characterized. We have analyzed the characteristics of potential T. cruzi CTL target molecules by expression of the model CTL target molecule chicken OVA in different cellular compartments of T. cruzi. OVA (amino acids 139-385) was expressed as a secretory, cytoplasmic, transmembrane, or glycosylphosphatidylinositol-anchored protein in T. cruzi transfectants. Host cells infected with T. cruzi transfectants that secreted or released OVA, but not those producing cytoplasmic or transmembrane forms of OVA, could process and present OVA peptide via the class I MHC pathway, as indicated by the stimulation of OVA-specific CD8+ T cell hybridomas and the cytolysis of host cells infected with OVA-secreting parasites by OVA-specific CTLs. In addition, infection of mice with OVA-secreting parasites elicited the production of OVA-specific CTLs. These studies demonstrate the ability to target proteins to specific cellular compartments in T. cruzi using either trypanosomal or mammalian signal sequences. Furthermore, these results suggest that proteins secreted or released by T. cruzi in infected cells are a major source of peptides for MHC class I presentation and for the generation of parasite-specific CTL.


Electrochemical synthesis, characterization of Ir-Zn containing coordination polymer, and application in oxygen and glucose sensing.
A simple and sensitive biosensor array based on phosphorescence detection that is able to detect oxygen and glucose in human serum, respectively, has been developed. We demonstrate an electrochemical method as a fast, effective, tunable, and versatile means of growing phosphorescence sensing material. This sensing material, crystalline iridium(III)-Zn(II) coordination polymers, namely Ir-Zn(e), was grown on a stainless steel mesh and then doped in a sol-gel matrix. The emission of Ir-Zn(e) was ascribed to a metal-to-ligand charge transfer transition (MLCT). The noteworthy oxygen-sensing properties of Ir-Zn(e) were also evaluated. The optimal oxygen-sensing conditions of Ir-Zn(e) with a deduced K(SV) value of 3.55 were 5 V and 30 °C for 1 hour. Moreover, the short response time (23 s) and the recovery time (21 s) toward oxygen have been measured. The reversibility experiment was carried out for eleven cycles. The resulting >70% recovery of intensity for Ir-Zn(e) on each cycle demonstrated a high degree of reproducibility during the sensing process. The detection limit could be 0.050% for gaseous oxygen. The sensing substrate was subsequently built up under glucose oxidase encapsulated in hydrogel and then immobilized on an egg membrane by the layer-by-layer method. Once the glucose solution was injected into this array, oxygen content depleted simultaneously with a concomitant increase in the phosphorescence of coordination polymers. The linear dynamic range for the determination of glucose was 0.1-6.0 mM, the correlation coefficient (R(2)) was 0.9940 (y = 0.75 [glucose] + 0.539), and the response time was less than 120 s. The minimum detectable concentration for glucose was calculated to be 0.05 mM from three times signal to noise. The photophysical properties of the sensing material and the effects of buffer concentration, pH, interference, matrix effect, temperature, and the stability of the biosensor array have also been studied in detail. The biosensor array was successfully applied to the determination of glucose in human serum.


Using an extended kalman filter for rigid body pose estimation.
Rigid body pose is commonly represented as the rigid body transformation from one (often reference) pose to another This is usually computed for each frame of data without any assumptions or restrictions on the temporal change of the pose. The most common algorithm was proposed by Söderkvist and Wedin (1993, "Determining the Movements of the Skeleton Using Well-configured Markers," J. Biomech., 26, pp. 1473-1477), and implies the assumption that measurement errors are isotropic and homogenous. This paper describes an alternative method based on a state space formulation and the application of an extended Kalman filter (EKF). State space models are formulated, which describe the kinematics of the rigid body. The state vector consists of six generalized coordinates (corresponding to the 6 degrees of freedom), and their first time derivatives. The state space models have linear dynamics, while the measurement function is a non-linear relation between the state vector and the observations (marker positions). An analytical expression for the linearized measurement function is derived. Tracking the rigid body motion using an EKF enables the use of a priori information on the measurement noise and type of motion to tune the filter. The EKF is time variant, which allows for a natural way of handling temporarily missing marker data. State updates are based on all the information available at each time step, even when data from fewer than three markers are available. Comparison with the method of Söderkvist and Wedin on simulated data showed a considerable improvement in accuracy with the proposed EKF method when marker data was temporarily missing. The proposed method offers an improvement in accuracy of rigid body pose estimation by incorporating knowledge of the characteristics of the movement and the measurement errors. Analytical expressions for the linearized system equations are provided, which eliminate the need for approximate discrete differentiation and which facilitate a fast implementation.


Focusing properties of surface plasmon polariton floating dielectric lenses.
We have investigated the focusing properties of surface plasmon polariton floating dielectric lenses. An analysis of the scattering characteristics of surface plasmon polaritons using a floating dielectric block shows that the air-gap thickness between a floating dielectric block and a metal substrate can be an effective dynamic variable for modulating the amplitude and phase of the transmission coefficient of the surface plasmon polaritons. This property can be used to realize a variable-focusing surface plasmon dielectric lens with the air-gap thickness as the dynamic variable. The focusing properties of a Fresnel lens and a parabolic lens with respect to the air-gap thickness are compared and analyzed.


Photonic measurement of microwave frequency based on phase modulation.
A photonic approach for microwave frequency measurement is proposed. In this approach, an optical carrier is modulated by an unknown microwave signal through a phase modulator. The modulated optical signal is then split into two parts; one part passes through a spool of polarization maintaining fiber (PMF) and the other one, through a dispersion compensation fiber (DCF), to introduce different microwave power penalties. After the microwave powers of the two parts are measured by two photodetectors, a fixed frequency-to-power mapping is established by obtaining an amplitude comparison function (ACF). A proof-of-concept experiment demonstrates frequency measurement over a range of 10.5 GHz, with measurement error less than +/-0.07 GHz.


The extraction of simple relationships in growth factor-specific multiple-input and multiple-output systems in cell-fate decisions by backward elimination PLS regression.
Cells use common signaling molecules for the selective control of downstream gene expression and cell-fate decisions. The relationship between signaling molecules and downstream gene expression and cellular phenotypes is a multiple-input and multiple-output (MIMO) system and is difficult to understand due to its complexity. For example, it has been reported that, in PC12 cells, different types of growth factors activate MAP kinases (MAPKs) including ERK, JNK, and p38, and CREB, for selective protein expression of immediate early genes (IEGs) such as c-FOS, c-JUN, EGR1, JUNB, and FOSB, leading to cell differentiation, proliferation and cell death; however, how multiple-inputs such as MAPKs and CREB regulate multiple-outputs such as expression of the IEGs and cellular phenotypes remains unclear. To address this issue, we employed a statistical method called partial least squares (PLS) regression, which involves a reduction of the dimensionality of the inputs and outputs into latent variables and a linear regression between these latent variables. We measured 1,200 data points for MAPKs and CREB as the inputs and 1,900 data points for IEGs and cellular phenotypes as the outputs, and we constructed the PLS model from these data. The PLS model highlighted the complexity of the MIMO system and growth factor-specific input-output relationships of cell-fate decisions in PC12 cells. Furthermore, to reduce the complexity, we applied a backward elimination method to the PLS regression, in which 60 input variables were reduced to 5 variables, including the phosphorylation of ERK at 10 min, CREB at 5 min and 60 min, AKT at 5 min and JNK at 30 min. The simple PLS model with only 5 input variables demonstrated a predictive ability comparable to that of the full PLS model. The 5 input variables effectively extracted the growth factor-specific simple relationships within the MIMO system in cell-fate decisions in PC12 cells.


Testing cord blood human chorionic gonadotropin as a surrogate marker for early identification of human immunodeficiency virus-1 infection in children.
We measured human chorionic gonadotropin (hCG) in cord sera of 22 infants born to women infected with the human immunodeficiency virus-1 (HIV-1). hCG was also determined in cord sera from 173 infants born at a suburban hospital to HIV-1-seronegative women. The findings indicate that 16 (9%) of 173 HIV-1-seronegative samples had hCG levels greater than 90 IU/L (values were distributed as a Poisson curve). In contrast, 8 (36%) of the 22 infants born to HIV-1-infected women had hCG levels in excess of 90 IU/L, and 7 (88%) of these were shown to be HIV-infected. The remaining 14 infants born to HIV-1-infected women had low hCG levels, and 3 (21%) of the 14 had HIV infection. Mean follow-up time for HIV-uninfected infants was 17.5 months (range 9 months to 3 years). A statistically significant association between maternal-fetal HIV-1 transmission and hCG levels > or = 90 IU/L in cord sera was observed (p = 0.02). The difference between CD4 counts among mothers who transmitted HIV and those who did not was also statistically significant (p = 0.025). On the basis of this study's findings, we propose that cord blood hCG may serve as a surrogate marker for HIV-1 infection. Testing hCG levels in cord sera is an inexpensive and readily available screening test for early identification of infants at increased risk for getting HIV-1 from their mothers.


Observing and modeling BMCC degradation by commercial cellulase cocktails with fluorescently labeled Trichoderma reseii Cel7A through confocal microscopy.
Understanding the depolymerization mechanisms of cellulosic substrates by cellulase cocktails is a critical step towards optimizing the production of monosaccharides from biomass. The Spezyme CP cellulase cocktail combined with the Novo 188 β-glucosidase blend was used to depolymerize bacterial microcrystalline cellulose (BMCC), which was immobilized on a glass surface. The enzyme mixture was supplemented with a small fraction of fluorescently labeled Trichoderma reseii Cel7A, which served as a reporter to track cellulase binding onto the physical structure of the cellulosic substrate. Both micro-scale imaging and bulk experiments were conducted. All reported experiments were conducted at 50 °C, the optimal temperature for maximum hydrolytic activity of the enzyme cocktail. BMCC structure was observed throughout degradation by labeling it with a fluorescent dye. This method allowed us to measure the binding of cellulases in situ and follow the temporal morphological changes of cellulose during its depolymerization by a commercial cellulase mixture. Three kinetic models were developed and fitted to fluorescence intensity data obtained through confocal microscopy: irreversible and reversible binding models, and an instantaneous binding model. The models were successfully used to predict the soluble sugar concentrations that were liberated from BMCC in bulk experiments. Comparing binding and kinetic parameters from models with different assumptions to previously reported constants in the literature led us to conclude that exposing new binding sites is an important rate-limiting step in the hydrolysis of crystalline cellulose.


Clinical utility of the Stanford brief activity survey in men and women with early-onset coronary artery disease.
To determine the utility of the Stanford Brief Activity Survey (SBAS) as a quick screening tool in a clinical population, where no other measure of physical activity was available. The SBAS was administered to 500 younger cases in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study, a case-control genetic association study, between December 2001 and January 2004. Younger cases in the ADVANCE study included men (<46 years old) and women (<56 years old) diagnosed with early-onset coronary artery disease. Frequency distributions of the SBAS and associations between SBAS activity categories and selected cardiovascular disease risk factors by sex were calculated. Subjects were 45.9 +/- 6.4 years old, 68% married, 61% women, 51% white, and 21% college graduates. Clinical diagnoses for early-onset coronary artery disease included 61% myocardial infarction, 23% coronary revascularization procedure, and 16% angina pectoris. In women, associations between all cardiovascular disease risk factors examined across SBAS categories were statistically significant (P trend < .01). In men, the associations across SBAS categories were statistically significant (P trend < .01), except for body mass index (P trend = .065). Adjustment for body mass index, age, ethnicity, and education with interactions by sex did not change the results. Subjects in the higher SBAS activity categories had more favorable cardiovascular disease risk profiles than did their less active counterparts, regardless of sex. The SBAS can be recommended for use in clinical populations providing immediate feedback on current physical activity level.


Load deflection characteristics of square and rectangular archwires.
To determine and compare the relative stiffness of a large selection of commonly-used square and rectangular steel, super-tempered steel, NiTi, and TMA orthodontic archwires of various cross-sections, in order to provide the clinician with a useful, easy-to-consult guide to archwire sequence selection. Twenty-four archwires of different cross-section shape, size and material were selected. Each type was subjected to a modified three-point bending test, performed in triplicate using an Instron 4467 dynamometer. Each sample was deflected by 1mm, and the corresponding load recorded. The relative stiffness of each archwire sample was calculated, and samples were compared by material and by cross-section. A considerable difference in resistance to deflection was revealed between all the tested archwires. As expected, the resistance to deflection of archwires of the same cross-section was found to increase with increasing stiffness of their construction material. Specifically, steel archwires can be as much as 8 times stiffer than NiTi archwires of the same shape and cross-section, and super-tempered steel archwires are invariably stiffer than traditional steel versions. Marked differences in resistance to deflection were also found between NiTi archwires made of the same material but with different shape characteristics. In archwires of the same cross-section, steel is always stiffer than TMA and NiTi, and super-tempered steel is always stiffer than conventional steels. In archwires of the same material, the stiffness increases with the cross-section, in particular with its height.


Assessing the burden of intestinal parasites affecting newly arrived immigrants in Qatar.
In the last decades, the enormous influx of immigrants to industrialized countries has led to outbreaks of parasitic diseases, with enteric infections being amongst the most frequently encountered. In its strategy to control such infection, Qatar has established the Pre-Employment Certificate (PEC) program which requires medical inspection before arrival in Qatar and which is mandatory for immigrant workers travelling to the country. To assess the reliability of the PEC, we conducted a survey of intestinal parasites, based on examination of stool samples provided by immigrant workers (n = 2,486) recently arrived in Qatar. Overall prevalence of helminths was 7.0% and that of protozoa was 11.7%. Prevalence of combined helminths was highest among the western Asians and the highest prevalence of combined protozoan parasites was among workers from North to Saharan Africa. Analysis of temporal changes showed an increasing trend of protozoan infections over the investigated 3 years. A major contribution to this temporal change in prevalence came from Blastocystis hominis as well as from other protozoan species: Giardia duodenalis and Endolimax nana. Analysis of the temporal trend in species richness of the protozoan species showed a significant increase in the mean number of species harboured per subject across this period. The increase of protozoan infections over recent years raises some concerns. It suggests that screening protocols for applicants for visas/work permits needs to be revised giving more careful attention to the intestinal protozoan infections that potential immigrants may harbor.


Noise filtering in parametric amplification by dressing the seed beam with spatial chirp.
We report a method for filtering out the noises produced in optical parametric chirped-pulse amplifiers by dressing the seed beam with spatial chirp. After dechirping the amplified signal with a compressor, the noises experience a spatiotemporal coupling, making themselves highly distinguishable from the compressed signal in space, and hence supporting noise filtering effectively and expediently in the spatial domain, which would otherwise not be possible. Numerical simulations performed for the proposed method show the capabilities of an order of magnitude reduction in the noise energy and several orders of magnitude enhancement in the temporal contrast.


Guidelines for laboratory test result reporting of human immunodeficiency virus type 1 ribonucleic acid determination. Recommendations from a CDC working group. Centers for Disease Control.
Monitoring human immunodeficiency virus type 1 (HIV-1) ribonucleic acid levels (also known as HIV viral load) has become the standard of care for monitoring response to therapy in HIV-infected patients. In 1999, CDC published updated surveillance case definitions for HIV infection and acquired immunodeficiency syndrome (AIDS) reporting, including positive results of HIV-1 viral detection tests (CDC. Guidelines for national human immunodeficiency virus case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome. MMWR 1999;48[No. RR-131:1-28). Since 1996, an increased number of public and private laboratories have begun performing viral load tests. Results obtained with available test methods are variable, and laboratories present these results in different ways, indicating that guidelines to promote standard practice in reporting of test results are warranted. This report provides guidelines for standardized reporting of viral load test results by licensed laboratories to health-care providers and facilities for public health case reporting of HIV infection and AIDS. Recommended standards were developed through data review, input involving a working group of physicians and laboratorians experienced in viral load testing, and an assessment of laboratory practices. These guidelines were discussed, refined, and endorsed at the annual Human Retrovirus and Hepatitis C Laboratory Testing Conference, held March 6-9, 2000, in Charlotte, North Carolina, with participation of representatives from public health, hospital, independent, and blood-collection-facility laboratories. Adoption of these guidelines by all public and private laboratories that perform HIV viral load testing will improve the quality and usefulness of viral load test results for the physician ordering the test and for reporting to public health departments.


Glucagon Clearance is Preserved in Type 2 Diabetes.
Hyperglucagonemia is a common observation in both obesity and type 2 diabetes, and the etiology is primarily thought to be hypersecretion of glucagon. We investigated whether altered elimination kinetics of glucagon could contribute to the hyperglucagonemia in type 2 diabetes and obesity. Individuals with type 2 diabetes and preserved kidney function (8 with and 8 without obesity) and matched control individuals (8 with and 8 without obesity) were recruited. Each participant underwent a 1-hour glucagon infusion (4 ng/kg/min), achieving steady-state plasma glucagon concentrations, followed by a 1-hour wash-out period. Plasma levels, the metabolic clearance rate (MCR), half-life (T½) and volume of distribution of glucagon were evaluated and a pharmacokinetic model was constructed. Glucagon MCR and volume of distribution were significantly higher in the type 2 diabetes group compared to the control group, while no significant differences between the groups were found in glucagon T½ Individuals with obesity had neither a significantly decreased MCR, T½, nor volume of distribution of glucagon. In our pharmacokinetic model, glucagon MCR associated positively with fasting plasma glucose and negatively with body weight. In conclusion, our results suggest that impaired glucagon clearance is not a fundamental part of the hyperglucagonemia observed in obesity and type 2 diabetes.


The role of risk perception in willingness to respond to the 2014-2016 West African Ebola outbreak: a qualitative study of international health care workers.
The 2014-2016 West Africa Ebola Virus Disease (EVD) outbreak was an unprecedented public health event, and in addition to claiming over 11,000 lives, it resulted in the deaths of more healthcare workers than any outbreak in recent history. While a cadre of willing and able health workers is essential for an effective epidemic response, health workforce capacity in times of crisis may be significantly impacted by how risks are perceived by health staff. This study aimed to explore how risk perceptions influenced healthcare workers' willingness to respond during this outbreak. Through in-depth interviews with 11 front-line international health care workers who chose to respond to the West Africa outbreak, this qualitative study explores how perceptions of risk developed and subsequently mediated the decision to respond to the outbreak. Data was thematically organized using NVivo 10. We found that numerous individual and social-level factors played a role in modifying risk perception in health workers. Institutional trust emerged as a key risk attenuator, as did past experience, self-efficacy, duty of care, humanitarian ethos, and cognitive heuristics. Feelings of risk were amplified by infections of co-workers, and risk perceptions of family members and the public, which were mainly informed by media reports, also hampered willingness to respond in some cases. Understanding the risk perceptions of health workers, institutions, and the public, while complex and interdependent, are each crucial to understand for an effective public health response to epidemics, and as such should be taken into consideration in future program planning and research.


MiR-21 is an EGFR-regulated anti-apoptotic factor in lung cancer in never-smokers.
Fifteen percent of lung cancer cases occur in never-smokers and show characteristics that are molecularly and clinically distinct from those in smokers. Epidermal growth factor receptor (EGFR) gene mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 cases of never-smoker lung cancer identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., up-regulated miR-21) and unidentified (e.g., down-regulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs, including miR-21, were more remarkable in cases with EGFR mutations than in those without these mutations. A significant correlation between phosphorylated-EGFR (p-EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggest that the EGFR signaling is a pathway positively regulating miR-21 expression. In the never-smoker-derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p-EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker-derived adenocarcinoma cell line H441 with wild-type EGFR, the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is enhanced further by the activated EGFR signaling pathway, plays a significant role in lung carcinogenesis in never-smokers, as well as in smokers, and is a potential therapeutic target in both EGFR-mutant and wild-type cases.


Acute splenic torsion in children: which is the best treatment? A case report.
Wandering spleen is a clinical entity which rarely affects children and adolescents. This condition can be asymptomatic or responsible of chronic pain, but it appears as a surgical emergency when an acute twisting occurs. The risk of post-splenectomy sepsis in the pediatric population suggests a conservative approach whenever possible, and also in case of acute torsion, most authors prefer to preserve the spleen and perform a splenopexy. The Authors describe a case of a child with acute splenic torsion, in whom a conservative surgical approach was initially adopted. The conservative option has to be balanced with the risk of prolonged thrombocytopenia, multiple transfusions and a possible second procedure to remove the spleen.


Parathyroid autotransplantation.
Although rare following initial cervical exploration, reoperative parathyroid surgery may cause permanent hypoparathyroidism in 15% to 30% of patients. Immediate fresh or delayed cryopreserved parathyroid autotransplantation is the principal surgical option to resolve this complication. Between 1980 and 1990, 18 and 12 patients underwent immediate and cryopreserved autotransplantation, respectively. With a mean follow-up of nearly 5 years, 61% of the immediate and 42% of the cryopreserved tissue showed evidence of function. However, only 10 (55%) and two (17%) of the respective patients had completely discontinued treatment with calcium supplementation. Graft-dependent hypercalcemia can occur with either technique. We conclude that until cryopreserved tissue can be transplanted with more reliable success and if the excised abnormal parathyroid likely represents the only remaining gland, we would advise immediate autotransplantation. In the reoperative setting, unless a residual normal parathyroid gland is confirmed, a portion of the excised parathyroid tissue should be cryopreserved for possible autotransplantation in case hypoparathyroidism develops subsequently.