Executive performance is related to regional gray matter volume in healthy older individuals.
Individual differences in executive functioning and brain morphology are considerable. In this study, we investigated their interrelation in a large sample of healthy older individuals. Digit span, trail-making, and Stroop tasks were used to assess different executive subfunctions in 367 nondemented community-dwelling individuals (50-81 years). Task performance was analyzed relative to brain structure using voxel-based morphometry, corrected for age and sex. Improved task performance was associated with increased local gray matter volume in task-specific patterns that showed partial, but not complete overlap with known task-specific functional imaging patterns. While all three tasks showed associations with prefrontal gray matter volume as expected for executive functioning, the strongest overlap between the three tasks was found in insular cortex, suggesting that it has a previously underestimated role for executive functions. The association between the insular cortex and executive functioning was corroborated using stereological region-of-interest measurement of insular volume in a subgroup of 93 subjects. Quantitatively, the volume of the single most strongly related region explained 2.4 ± 1.1% of the variance in executive performance over and above the variance explained by age, which amounted to 7.4 ± 4.1%. The age-independent peak associations between executive performance and gray matter described here occurred in regions that were also strongly affected by age-related gray matter atrophy, consistent with the hypothesis that age-related regional brain volume loss and age-related cognitive changes are linked.


Studies of the human c-myb gene and its product in human acute leukemias.
The myb gene is the transforming oncogene of the avian myeloblastosis virus (AMV); its normal cellular homolog, c-myb, is conserved across a broad span of evolution. In humans, c-myb is expressed in malignant hematopoietic cell lines and in primary hematopoietic tumors. Partial complementary DNA clones were generated from blast cells of patients with acute myelogenous leukemia. The sequences of the clones were compared to the c-myb of other species, as well as the v-myb of AMV. In addition, the carboxyl terminal region of human c-myb was placed in an expression vector to obtain protein for the generation of antiserum, which was used to identify the human c-myb gene product. Like v-myb, this protein was found within the nucleus of leukemic cells where it was associated with the nuclear matrix. These studies provide further evidence that c-myb might be involved in human leukemia.


Hyperpolarized 1H and 13C NMR Spectroscopy in a Single Experiment for Metabolomics.
The application of NMR spectroscopy to complex mixture analysis and, in particular, to metabolomics is limited by the low sensitivity of NMR. We recently showed that dissolution dynamic nuclear polarization (d-DNP) could enhance the sensitivity of 13C NMR for complex metabolite mixtures, leading to the detection of highly sensitive 13C NMR fingerprints of complex samples such as plant extracts or urine. While such experiments provide heteronuclear spectra, which are complementary to conventional NMR, hyperpolarized 1H NMR spectra would also be highly useful, with improved limits of detection and compatibility with the existing metabolomics workflow and databases. In this technical note, we introduce an approach capable of recording both 1H and 13C hyperpolarized spectra of metabolite mixtures in a single experiment and on the same hyperpolarized sample. We investigate the analytical performance of this method in terms of sensitivity and repeatability, and then we show that it can be efficiently applied to a plant extract. Significant sensitivity enhancements in 1H NMR are reported with a repeatability suitable for metabolomics studies without compromising on the performance of hyperpolarized 13C NMR. This approach provides a way to perform both 1H and 13C hyperpolarized NMR metabolomics with unprecedented sensitivity and throughput.


Hierarchical cognitive and psychosocial predictors of amnestic mild cognitive impairment.
To identify neuropsychological and psychosocial factors predictive of amnestic Mild Cognitive Impairment (aMCI) among a group of 94 nondemented older adults, we employed a novel nonlinear multivariate classification statistical method called Optimal Data Analysis (ODA) in a dataset collected annually for 3 years. Performance on measures of memory and visuomotor processing speed or symptoms of depression in year 1 predicted aMCI status by year 2. Performance on a measure of learning at year 1 predicted aMCI status at year 3. No other measures significantly predicted incidence of aMCI at years 2 and 3. Results support the utility of multiple neuropsychological and psychosocial measures in the diagnosis of aMCI, and the present model may serve as a testable hypothesis for prospective investigations of the development of aMCI.


The Hoeppli phenomenon in schistosomiasis japonica: historical findings and additional investigation in bovines.
The present paper deals with a buried knowledge of the early findings of the Hoeppli phenomenon in cattle infected with Schistosoma japonicum together with a revised list of bovines and other mammalian species in which this phenomenon has been found. It was noted that the percentage of the mature-egg granulomas with positive Hoeppli phenomena varied with the species of bovines, ie, higher positive percentage in the more susceptible cattle than in the less susceptible buffalos. The radiating filaments in fringes of the phenomenon were also stronger in cattle than in buffalos.


Deep Learning Enables Accurate Diagnosis of Novel Coronavirus (COVID-19) With CT Images.
A novel coronavirus (COVID-19) recently emerged as an acute respiratory syndrome, and has caused a pneumonia outbreak world-widely. As the COVID-19 continues to spread rapidly across the world, computed tomography (CT) has become essentially important for fast diagnoses. Thus, it is urgent to develop an accurate computer-aided method to assist clinicians to identify COVID-19-infected patients by CT images. Here, we have collected chest CT scans of 88 patients diagnosed with COVID-19 from hospitals of two provinces in China, 100 patients infected with bacteria pneumonia, and 86 healthy persons for comparison and modeling. Based on the data, a deep learning-based CT diagnosis system was developed to identify patients with COVID-19. The experimental results showed that our model could accurately discriminate the COVID-19 patients from the bacteria pneumonia patients with an AUC of 0.95, recall (sensitivity) of 0.96, and precision of 0.79. When integrating three types of CT images, our model achieved a recall of 0.93 with precision of 0.86 for discriminating COVID-19 patients from others. Moreover, our model could extract main lesion features, especially the ground-glass opacity (GGO), which are visually helpful for assisted diagnoses by doctors. An online server is available for online diagnoses with CT images by our server (http://biomed.nscc-gz.cn/model.php). Source codes and datasets are available at our GitHub (https://github.com/SY575/COVID19-CT).


Single cell phospho-specific flow cytometry can detect dynamic changes of phospho-Stat1 level in lung cancer cells.
Single cell phospho-specific flow cytometry (SCPFC) enables the investigation of signaling network interactions and the categorization of disease outcome. While this method has been successfully used to study hematologic disorders, its application on solid tumors has not been examined. This study aimed to demonstrate the ability of SCPFC to detect dynamic changes of Tyrosine phospho-Stat1 (pStat1) in solid tumor models and in human tumor samples. In the human lung cancer cell line PC14PE6/AS2, the fluorescence intensity changes of pStat1 after IFN-γ stimulation were compatible to results obtained by Western blot analysis. In metastatic animal models, cancer cells from subcutaneous tumors, malignant ascites, and peritoneal tumors responded to IFN-γ. The pStat1 was activated in these cells after IFN-γ stimulation, with a 1.5- to 2.5-fold increase in fluorescence intensity compared to the unstimulated control. To examine the potential clinical application of SCPFC, cancer cells were collected from malignant pleural effusions (MPEs) of lung cancer patients to observe the activation of pStat1 after IFN-γ stimulation. Cell apoptosis after cisplatin treatment was evaluated by Annexin V staining, which showed that MPE cancer cells with higher pStat1 changes after IFN-γ stimulation were more resistant to cisplatin. In conclusion, there is a preliminary application of SCPFC to solid tumors and links to drug sensitivity are promising.


Epigenetic influences of low-dose bisphenol A in primary human breast epithelial cells.
Substantial evidence indicates that exposure to bisphenol A (BPA) during early development may increase breast cancer risk later in life. The changes may persist into puberty and adulthood, suggesting an epigenetic process being imposed in differentiated breast epithelial cells. The molecular mechanisms by which early memory of BPA exposure is imprinted in breast progenitor cells and then passed onto their epithelial progeny are not well understood. The aim of this study was to examine epigenetic changes in breast epithelial cells treated with low-dose BPA. We also investigated the effect of BPA on the ERα signaling pathway and global gene expression profiles. Compared to control cells, nuclear internalization of ERα was observed in epithelial cells preexposed to BPA. We identified 170 genes with similar expression changes in response to BPA. Functional analysis confirms that gene suppression was mediated in part through an ERα-dependent pathway. As a result of exposure to BPA or other estrogen-like chemicals, the expression of lysosomal-associated membrane protein 3 (LAMP3) became epigenetically silenced in breast epithelial cells. Furthermore, increased DNA methylation in the LAMP3 CpG island was this repressive mark preferentially occurred in ERα-positive breast tumors. These results suggest that the in vitro system developed in our laboratory is a valuable tool for exposure studies of BPA and other xenoestrogens in human cells. Individual and geographical differences may contribute to altered patterns of gene expression and DNA methylation in susceptible loci. Combination of our exposure model with epigenetic analysis and other biochemical assays can give insight into the heritable effect of low-dose BPA in human cells.


Investigating alcohol consumption as a risk factor for HIV transmission in heterosexual settings in sub-Saharan African communities.
Alcohol consumption and abuse is widespread in sub-Saharan Africa where most HIV infections occur and has been associated with risky sexual behaviors. It may therefore be one of the most common, potentially modifiable HIV risk factors in this region. A deterministic system of ordinary differential equations incorporating heterogeneity and biased sexual preferences is formulated to assess the effects of alcohol consumption on the transmission dynamics of the disease in heterosexual settings. Extensive qualitative analysis of the model is carried out and epidemic threshold such as the alcohol-induced reproductive number (RA), and equilibria are derived and their stabilities examined. The disease-free equilibrium is found to be globally attracting whenever the reproductive number is less than unity. In the model, heterosexuality is the source of transmissions, and therefore, targeting a reduction of the basic reproductive number (R0) should be primary objective for any intervention programme. We show that the preference to form partnerships amongst the heterogeneous groups influences the severity of disease and its evolution, and consequently the rate of partnership formation between females and alcohol consumers and their relative infectiousness over nondrinkers has a huge positive correlation with the alcohol-induced reproductive number and hence the epidemic. The proportion or absolute number of drinkers is shown to have minimal influence on the disease dynamics, and in a community with alcohol consumers, it is more prudent to reduce their risk sexual behavior rather than to fight the spread of alcohol consumption. Thus, intervention measures targeted at reducing heterogeneous group interactions and behavior change are the key to disease control in these settings.


Association Between Radiologic Incidental Findings and Resource Utilization in Patients Admitted With Chest Pain in an Urban Medical Center.
Increasing use of testing among hospitalized patients has resulted in an increase in radiologic incidental findings (IFs), which challenge the provision of high-value care in the hospital setting. To understand impact of radiologic incidental findings on resource utilization in patients hospitalized with chest pain. Retrospective observational cross sectional study. Academic medical center. Adult patients hospitalized with principal diagnosis of chest pain. Demographic, imaging, and length of stay (LOS) data were abstracted from the medical charts. We used multiple logistic regression to evaluate factors associated with radiologic IFs and negative binomial regression to evaluate the association between radiologic IFs and LOS. 1811 consecutive admissions with chest pain were analyzed retrospectively over a period of 24 months; 376 patients were included in the study after exclusion criteria were applied and readmissions removed. Of these, 197 patients (52%) had 364 new radiologic IFs on imaging; most IFs were of minor (50%) or moderate clinical significance (42%), with only 7% of major significance. Odds of finding radiologic IFs increased with age (adjusted odds ratio, 1.04; 95% confidence interval [CI], 1.01-1.06) and was associated with a 26% increase in LOS (adjusted incidence rate ratio, 1.26; 95% CI, 1.07-1.49). Radiologic IFs were very common among patients hospitalized with chest pain of suspected cardiac origin and independently associated with an increase in the LOS. Interventions to address radiologic IFs may reduce LOS and, thereby, support high-value care. Journal of Hospital Medicine 2017;12:323-328.


American Clinical Neurophysiology Society Guideline 5: Minimum Technical Standards for Pediatric Electroencephalography.
This revision to the EEG Guidelines is an update incorporating the current electroencephalography technology and practice. It was previously published as Guideline 2. Similar to the prior guideline, it delineates the aspects of Guideline 1 that should be modified for neonates and young children. Recording conditions for photic stimulation and hyperventilation are revised to enhance the provocation of epileptiform discharges. Revisions recognize the difficulties involved in performing an EEG under sedation in young children. Recommended neonatal EEG montages are displayed for the reduced set of electrodes only since the montages in Guideline 3 should be used for a 21-electrode 10-20 system array. Neonatal documentation is updated to use current American Academy of Pediatrics term "postmenstrual age" rather than "conceptional age." Finally, because therapeutic hypothermia alters the prognostic value of neonatal EEG, the necessity of documenting the patient's temperature at the time of recording is emphasized.


Golgi targeting of human guanylate-binding protein-1 requires nucleotide binding, isoprenylation, and an IFN-gamma-inducible cofactor.
Human guanylate-binding protein-1 (hGBP-1) is a large GTPase, similar in structure to the dynamins. Like many smaller GTPases of the Ras/Rab family, it is farnesylated, suggesting it may dock into membranes and perhaps play a role in intracellular trafficking. To date, however, hGBP-1 has never been associated with a specific intracellular compartment. Here we present evidence that hGBP-1 can associate with the Golgi apparatus. Redistribution from the cytosol to the Golgi was observed by immunofluorescence and subcellular fractionation after aluminum fluoride treatment, suggesting that it occurs when hGBP-1 is in its GTP-bound state. Relocalization was blocked by a farnesyl transferase inhibitor. The C589S mutant of hGBP-1, which cannot be farnesylated, and the previously uncharacterized R48P mutant, which cannot bind GTP, both failed to localize to the Golgi. These two mutants had a dominant-negative effect, preventing endogenous wild-type hGBP-1 from efficiently redistributing after aluminum fluoride treatment. Furthermore, hGBP-1 requires another IFN-gamma-induced factor to be targeted to the Golgi, because constitutively expressed hGBP-1 remained cytosolic in cells treated with aluminum fluoride unless the cells were preincubated with IFN-gamma. Finally, two nonhydrolyzing mutants of hGBP-1, corresponding to active mutants of Ras family proteins, failed to constitutively associate with the Golgi; we propose three possible explanations for this surprising result.


IMAGING GENETICS VIA SPARSE CANONICAL CORRELATION ANALYSIS.
The collection of brain images from populations of subjects who have been genotyped with genome-wide scans makes it feasible to search for genetic effects on the brain. Even so, multivariate methods are sorely needed that can search both images and the genome for relationships, making use of the correlation structure of both datasets. Here we investigate the use of sparse canonical correlation analysis (CCA) to home in on sets of genetic variants that explain variance in a set of images. We extend recent work on penalized matrix decomposition to account for the correlations in both datasets. Such methods show promise in imaging genetics as they exploit the natural covariance in the datasets. They also avoid an astronomically heavy statistical correction for searching the whole genome and the entire image for promising associations.


Use of Human Fascia Lata in Rat Calvarial Bone Defects.
Tooth loss leads to a decrease in alveolar bone volume, and consequently to the need for guided bone regeneration (GBR) techniques to restore bone anatomy, and the adequate choice of therapy. Fascia lata membrane (FLM) has been used in surgical procedures in neurology, orthopedics, otorhinolaryngology, cardiology, vascular surgery, gynecology, and dentistry for guided tissue regeneration. The aim of the present preliminary study was to evaluate bone tissue response in rat calvarial bone defects covered with human fascia lata membrane (FLM). Eight Wistar rats, 230g body weight, were subjected to bone surgery to create a 5x5mm long/ 1mm deep calvarial bone defect on either side of the median suture, using a piezoelectric scalpel and irrigation. The animals were treated according to the following protocol: Group I (GI): placement of a single layer of FLM (Biotar, Rosario, Prov. de Santa Fe, Argentina) to cover the defects; Group II (GII): double layer of FLM to cover the defects; Group III: no membrane; Group IV: control. All the animals were euthanized 60 days post-surgery; the heads were resected, radiographed, decalcified, and processed for embedding in paraffin and Hematoxylin-Eosin and Masson's trichrome staining. All bone defects covered with a single or double layer of FLM showed adequate osteogenesis, and none exhibited an inflammatory response. Groups III and IV Control showed scant osteogenesis and no alterations in soft tissues. The results obtained with this experimental model show biocompatibility of FML with the surrounding tissues at the studied time points. No alterations were observed in osteocytic lacunae or osteocytes in the bone after osteotomy using a piezoelectric scalpel. Further studies need to be conducted to assess bone tissue response to FLM in combination with bone substitutes.


Correlations between genotyping and antibiograms of clinical isolates of Pseudomonas aeruginosa from three different south Indian hospitals.
To compare the molecular relationships and antibiograms of nosocomial isolates of Pseudomonas aeruginosa obtained from three different genres of hospitals located in Southern India, two located at Hyderabad (one private hospital and an ophthalmic hospital) and one in Puducherry (tertiary care teaching hospital). Each of these hospitals, which follow different infection control strategies and various problems associated with it, were investigated. Antibiograms generated by disk diffusion susceptibility testing for clinically relevant antibiotics and genotyping through fluorescent amplified fragment length polymorphism analysis (fAFLP) were the tools used in the study. Molecular genotyping revealed a heterogeneous group of unrelated molecular clusters of P. aeruginosa strains having higher resistance that are apparently being endemic throughout the tertiary care teaching hospital. In eye care hospital, only a few distinct strains of P. aeruginosa predominating the study period were shown to be responsible for outbreaks. The third private hospital witnessed a group of resistant and persistent strains that might have clonally originated from a diverse collection of strains. The divergent kind of strains in our study suggests that there may be a direct link between the infection control practices followed in each hospital and kind of strains isolated in that particular setup. The study also emphasizes the need for maintaining infection control practices in hospitals with superior standards, failure of which might result in thriving of persistent P. aeruginosa clones in the hospitals.


Eco-friendly synthesis, characterization, in vitro and in vivo anti-inflammatory activity of silver nanoparticle-mediated Selaginella myosurus aqueous extract.
There is emerging interest in medicinal plants in the biomedical field, due to their multitude of chemicals which show anti-inflammatory, antimicrobial, antiviral, or antitumoral potential. Research on medicinal plants has shown that nanotechnology could offer new solutions in the quality control, delivery aspects, or in sustaining herbal biological activities. This work reports on the preparation and characterization of silver nanoparticle-mediated Selaginella myosurus plant extract. Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, high-resolution scanning electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction have been used to characterize the prepared silver nanoparticles. The synthetic stability was studied by varying concentrations and pH of reactants. Egg albumin denaturation and carrageenan-induced rat paw edema model were used to ascertain the anti-inflammation. Ultraviolet-visible spectroscopy gave plasmon resonance ranging between 420 and 480 nm while Fourier transform infrared spectroscopy proved nano interface functionalized with organics. The powder X-ray diffraction pattern is in agreement with silver and silver chloride nanoparticles of crystallite size 33.7 nm and 44.2 nm for silver and silver chloride, respectively. Energy dispersive X-ray spectroscopy enables elemental characterization of the particles consisting of silver and silver chloride among main elements. Spherical silver grain of 58.81 nm average size has been depicted with high-resolution scanning electron microscopy and high-resolution transmission electron microscopy. Inhibitions of 99% and 60% were obtained in vitro and in vivo, respectively. The albumin denaturation and carrageenan-induced rat hind paw edema model to assess the anti-inflammatory potential of generated nanoparticles suggests that the silver nanoparticles may act as reducing/inhibiting agents on the release of acute inflammatory mediators. Hence, this work clearly demonstrated that silver nanoparticles mediated-Selaginella myosurus could be considered as a potential source for anti-inflammatory drugs.


Photoinduction of fast, reversible translational motion in a hydrogen-bonded molecular shuttle.
A rotaxane is described in which a macrocycle moves reversibly between two hydrogen-bonding stations after a nanosecond laser pulse. Observation of transient changes in the optical absorption spectrum after photoexcitation allows direct quantitative monitoring of the submolecular translational process. The rate of shuttling was determined and the influence of the surrounding medium was studied: At room temperature in acetonitrile, the photoinduced movement of the macrocycle to the second station takes about 1 microsecond and, after charge recombination (about 100 microseconds), the macrocycle shuttles back to its original position. The process is reversible and cyclable and has properties characteristic of an energy-driven piston.


Study of PEGylated lipid layers as a model for PEGylated liposome surfaces: molecular dynamics simulation and Langmuir monolayer studies.
We have combined Langmuir monolayer film experiments and all-atom molecular dynamics (MD) simulation of a bilayer to study the surface structure of a PEGylated liposome and its interaction with the ionic environment present under physiological conditions. Lipids that form both gel and liquid-crystalline membranes have been used in our study. By varying the salt concentration in the Langmuir film experiment and including salt at the physiological level in the simulation, we have studied the effect of salt ions present in the blood plasma on the structure of the poly(ethylene glycol) (PEG) layer. We have also studied the interaction between the PEG layer and the lipid bilayer in both the liquid-crystalline and gel states. The MD simulation shows two clear results: (a) The Na(+) ions form close interactions with the PEG oxygens, with the PEG chains forming loops around them and (b) PEG penetrates the lipid core of the membrane for the case of a liquid-crystalline membrane but is excluded from the tighter structure of the gel membrane. The Langmuir monolayer results indicate that the salt concentration affects the PEGylated lipid system, and these results can be interpreted in a fashion that is in agreement with the results of our MD simulation. We conclude that the currently accepted picture of the PEG surface layer acting as a generic neutral hydrophilic polymer entirely outside the membrane, with its effect explained through steric interactions, is not sufficient. The phenomena we have observed may affect both the interaction between the liposome and bloodstream proteins and the liquid-crystalline-gel transition and is thus relevant to nanotechnological drug delivery device design.


Saturn Anomalous Myriametric Radiation, a New Type of Saturn Radio Emission Revealed by Cassini.
A new radio component namely Saturn Anomalous Myriametric Radiation (SAM) is reported. A total of 193 SAM events have been identified by using all the Cassini Saturn orbital data. SAM emissions are L-O mode radio emission and occasionally accompanied by a first harmonic in R-X mode. SAM's intensities decrease with increasing distance from Saturn, suggesting a source near Saturn. SAM has a typical central frequency near 13 kHz, a bandwidth greater than 8 kHz and usually drifts in frequency over time. SAM's duration can extend to near 11 hr and even longer. These features distinguish SAM from the regular narrowband emissions observed in the nearby frequency range, hence the name anomalous. The high occurrence rate of SAM after low frequency extensions of Saturn Kilometric Radiation and the SAM cases observed during compressions of Saturn's magnetosphere suggest a special connection to solar wind dynamics and magnetospheric conditions at Saturn.


Novel peptide calcitonin gene-related peptide antagonists for migraine therapy.
It has previously been shown that the peptide (34Pro,35Phe)CGRP27-37 is a potent calcitonin gene-related peptide, CGRP receptor antagonist, and in this project we aimed to improve the antagonist potency through the structural modification of truncated C-terminal CGRP peptides. Six peptide analogues were synthesized and the anti-CGRP activity confirmed using both in vitro and in vivo studies. A 10 amino acid-containing peptide VPTDVGPFAF-NH2 (P006) was identified as a key candidate to take forward for in vivo evaluation, where it was shown to be an effective antagonist after intraperitoneal injection into mice. P006 was formulated as a preparation suitable for nasal administration by spray drying with chitosan to form mucoadhesive microcarriers (9.55 ± 0.91 mm diameter) and a loading of 0.2 mg peptide per 20 mg dose. The project has demonstrated the potential of these novel small peptide CGRP antagonists, to undergo future preclinical evaluation as anti-migraine therapeutics.


Interpretable and intervenable ultrasonography-based machine learning models for pediatric appendicitis.
Appendicitis is among the most frequent reasons for pediatric abdominal surgeries. Previous decision support systems for appendicitis have focused on clinical, laboratory, scoring, and computed tomography data and have ignored abdominal ultrasound, despite its noninvasive nature and widespread availability. In this work, we present interpretable machine learning models for predicting the diagnosis, management and severity of suspected appendicitis using ultrasound images. Our approach utilizes concept bottleneck models (CBM) that facilitate interpretation and interaction with high-level concepts understandable to clinicians. Furthermore, we extend CBMs to prediction problems with multiple views and incomplete concept sets. Our models were trained on a dataset comprising 579 pediatric patients with 1709 ultrasound images accompanied by clinical and laboratory data. Results show that our proposed method enables clinicians to utilize a human-understandable and intervenable predictive model without compromising performance or requiring time-consuming image annotation when deployed. For predicting the diagnosis, the extended multiview CBM attained an AUROC of 0.80 and an AUPR of 0.92, performing comparably to similar black-box neural networks trained and tested on the same dataset.


Layer 1 of somatosensory cortex: an important site for input to a tiny cortical compartment.
Neocortical layer 1 has been proposed to be at the center for top-down and bottom-up integration. It is a locus for interactions between long-range inputs, layer 1 interneurons, and apical tuft dendrites of pyramidal neurons. While input to layer 1 has been studied intensively, the level and effect of input to this layer has still not been completely characterized. Here we examined the input to layer 1 of mouse somatosensory cortex with retrograde tracing and optogenetics. Our assays reveal that local input to layer 1 is predominantly from layers 2/3 and 5 pyramidal neurons and interneurons, and that subtypes of local layers 5 and 6b neurons project to layer 1 with different probabilities. Long-range input from sensory-motor cortices to layer 1 of somatosensory cortex arose predominantly from layers 2/3 neurons. Our optogenetic experiments showed that intra-telencephalic layer 5 pyramidal neurons drive layer 1 interneurons but have no effect locally on layer 5 apical tuft dendrites. Dual retrograde tracing revealed that a fraction of local and long-range neurons was both presynaptic to layer 5 neurons and projected to layer 1. Our work highlights the prominent role of local inputs to layer 1 and shows the potential for complex interactions between long-range and local inputs, which are both in position to modify the output of somatosensory cortex.


Task-dependent organization of brain regions active during rest.
The human brain demonstrates complex yet systematic patterns of neural activity at rest. We examined whether functional connectivity among those brain regions typically active during rest depends on ongoing and recent task demands and individual differences. We probed the temporal coordination among these regions during periods of language comprehension and during the rest periods that followed comprehension. Our findings show that the topography of this "rest network" varies with exogenous processing demands. The network encompassed more highly interconnected regions during rest than during listening, but also when listening to unsurprising vs. surprising information. Furthermore, connectivity patterns during rest varied as a function of recent listening experience. Individual variability in connectivity strength was associated with cognitive function: more attentive comprehenders demonstrated weaker connectivity during language comprehension, and a greater differentiation between connectivity during comprehension and rest. The regions we examined have generally been thought to form an invariant physiological and functional network whose activity reflects spontaneous cognitive processes. Our findings suggest that their function extends beyond the mediation of unconstrained thought, and that they play an important role in higher-level cognitive function.


Cardiac resynchronization therapy in patients with minimal heart failure: a systematic review and meta-analysis.
The purpose of this study was to perform a systematic review and meta-analysis of prospective randomized clinical trials of cardiac resynchronization therapy (CRT) versus implantable cardioverter-defibrillator (ICD) in patients with reduced ejection fraction (EF), prolonged QRS interval, and New York Heart Association (NYHA) functional class I to II heart failure (HF). In patients with advanced HF, CRT improves left ventricular (LV) function and reduces mortality and hospitalizations. Recent data suggest that patients with milder HF also benefit from CRT. A meta-analysis of 5 clinical trials including 4,317 patients with NYHA functional class I/II HF was performed. Average age of patients was 65 years, and 80% were male. Frequency of all-cause mortality for CRT versus ICD was 8% versus 11.5% (risk ratio [RR]: 0.81; 95% confidence interval [CI]: 0.65 to 0.99, p = 0.04); for HF hospitalization, it was 11.6% versus 18.2% (RR: 0.68; 95% CI: 0.59 to 0.79, p < 0.001). Patients assigned to CRT had a significantly greater improvement in LVEF (+5.9% vs. +2.2%, p < 0.001) and LV volume than ICD patients. Among mildly symptomatic (NYHA functional class II) patients, CRT was associated with significantly lower mortality and HF hospitalization (RR: 0.73; 95% CI: 0.64 to 0.83), p < 0.001). In asymptomatic (NYHA functional class I) patients, HF hospitalization risk was lower (RR: 0.57; 95% CI: 0.34 to 0.97, p = 0.04) with CRT; however, there was no difference in mortality. Twelve asymptomatic HF patients needed to be treated with CRT to prevent 1 hospitalization. Cardiac resynchronization therapy decreases all-cause mortality, reduces HF hospitalizations, and improves LVEF in NYHA functional class I/II HF patients. Although there was a reduction in HF hospitalization with CRT for asymptomatic (NYHA functional class I) patients, risks versus benefits have to be carefully considered in this subgroup.


Interference Control in Working Memory Is Associated with Ventrolateral Prefrontal Cortex Volume.
Goal-irrelevant information may interfere with ongoing task activities if not controlled properly. Evidence suggests that the ability to control interference is connected mainly to the prefrontal cortex (pFC). However, it remains unclear whether gray matter (GM) volume in prefrontal regions influences individual differences in interference control (IC) and if these relationships are affected by aging. Using cross-sectional and longitudinal estimates over a 4- to 5-year period, we examined the relationship between relative IC scores, obtained from a 2-back working memory task, GM volumes, and performance in different cognitive domains. By identifying individuals with either no or high levels of interference, we demonstrated that participants with superior IC had larger volume of the ventrolateral pFC, regardless of participant demographics. The same pattern was observed both at baseline and follow-up. Cross-sectional estimates further showed that interference increased as a function of age, but interference did not change between baseline and follow-up. Similarly, across-sample associations between IC and pFC volume were found in the cross-sectional data, along with no longitudinal change-change relationships. Moreover, relative IC scores could be linked to composite scores of fluid intelligence, indicating that control of interference may relate to performance in expected cognitive domains. These results provide new evidence that a relative IC score can be related to volume of specific and relevant regions within pFC and that this relationship is not modulated by age. This supports a view that the GM volume in these regions plays a role in resisting interference during a working memory task.


Heart allograft involvement with Epstein-Barr virus-associated posttransplant lymphoproliferative disorder.
We describe a 60-year-old man who underwent heart transplant and died 5 months later. At autopsy, the patient was found to have posttransplant lymphoproliferative disorder (PTLD), which was not suspected ante mortem. The PTLD involved the lung, lymph nodes, spleen, and kidney and the intima of right coronary artery of the transplanted heart. Epstein-Barr virus infection was demonstrated on direct gel and dot blot after polymerase chain reaction amplification. In situ hybridization for Epstein-Barr virus DNA confirmed the presence of Epstein-Barr virus-infected lymphocytes in the intima of the right coronary artery of the cardiac allograft. To our knowledge, this case represents the first report of involvement of a heart allograft by PTLD in which Epstein-Barr virus infection of the atypical cells is documented. Although primary allograft involvement by PTLD has rarely been reported in heart transplant recipients, recognition that this may occur is important, since the lymphoid infiltrate of PTLD must be distinguished from the lymphoid infiltrate of acute rejection to avoid inappropriate therapy.


Constitutive repression of interleukin-1alpha in endothelial cells.
Activation of complement stimulates inflammation and provides an initial vigorous defense against infection. Insertion of the membrane attack complex in cell membranes of vascular endothelial cells induces changes in cell differentiation that promote coagulation, thrombosis, inflammation, and immunity. These changes are mediated by production of interleukin (IL)-1alpha by endothelial cells, which acts locally on endothelial cells to contain infection and promote healing of the affected site. In healthy tissues, however, promoting coagulation and inflammation would be dysphysiologic. Accordingly, endothelial cell activation by the membrane attack complex depends on both transcriptional regulation of IL-1alpha and availability of that cytokine to broadly modify endothelial cell physiology. Here, we report that the IL-1alpha gene contains a suppressor sequence that cooperates with histone modification to regulate production of IL-1alpha by endothelial cells. The suppressor sequence binds C/EBP (CCAAT enhancer-binding protein) family DNA-binding proteins isolated from the nucleus of quiescent endothelial cells. These results suggest constitutive suppression of IL-1alpha maintains quiescence of endothelium and that terminal complement complexes remove that suppression, allowing IL-1alpha transcription and, ultimately, activation of endothelium to proceed.


Microwave Enabled One-Pot, One-Step Fabrication and Nitrogen Doping of Holey Graphene Oxide for Catalytic Applications.
The unique properties of a holey graphene sheet, referred to as a graphene sheet with nanoholes in its basal plane, lead to wide range of applications that cannot be achieved by its nonporous counterpart. However, the large-scale solution-based production requires graphene oxide (GO) or reduced GO (rGO) as the starting materials, which take hours to days for fabrication. Here, an unexpected discovery that GO with or without holes can be controllably, directly, and rapidly (tens of seconds) fabricated from graphite powder via a one-step-one-pot microwave assisted reaction with a production yield of 120 wt% of graphite is reported. Furthermore, a fast and low temperature approach is developed for simultaneous nitrogen (N) doping and reduction of GO sheets. The N-doped holey rGO sheets demonstrate remarkable electrocatalytic capabilities for the electrochemical oxygen reduction reaction. The existence of the nanoholes provides a "short cut" for efficient mass transport and dramatically increases edges and surface area, therefore, creates more catalytic centers. The capability of rapid fabrication and N-doping as well as reduction of holey GO can lead to development of an efficient catalyst that can replace previous coin metals for energy generation and storage, such as fuel cells and metal-air batteries.


Alveolar and peripheral venous gas changes during breath-hold diving.
Two fit young men were tested in a laboratory pool at 22 degrees C and 1 m depth before and after hyperventilation/breath-hold diving lasting 90 seconds. The percentages of alveolar oxygen and carbon dioxide were determined on a Polygas analyser and converted to partial pressures (PAO2 and PACO2) at an atmospheric pressure of 86 kPa at 20 degrees C, room temperature. PAO2 and PACO2 values were cross-checked by collecting expiratory gas in a Douglas bag and using the Haldane gas analyser. Peripheral venous blood was 'arterialized' and analysed for CO2 (PVCO2) using the Radiometer ABL1 gas analyser. For ethical reasons, arterial punctures were not considered in these healthy subjects. Peripheral venous blood was obtained under near steady-state conditions from the dorsum of the hand, which was warmed to 38 degrees C. The results of hyperventilation/breath-hold diving are illustrated. PAO2 increased after hyperventilation and decreased to below 5 kPa after the dive. PACO2 decreased after hyperventilation and increased after the dive. PVCO2 decreased after hyperventilation and increased after the dive. All values approached a common point between 3 and 5 kPa after the 90-second dive. The CO2 content of arterialized peripheral venous blood closely follows that of alveolar air.


Acetylcholinesterase and neuropathy target esterase inhibitions in neuroblastoma cells to distinguish organophosphorus compounds causing acute and delayed neurotoxicity.
The differential inhibition of the target esterases acetylcholinesterase (AChE) and neuropathy target esterase (NTE, neurotoxic esterase) by organophosphorus compounds (OPs) is followed by distinct neurological consequences in exposed subjects. The present study demonstrates that neuroblastoma cell lines (human SH-SY5Y and murine NB41A3) can be used to differentiate between neuropathic OPs (i.e., those inhibiting NTE and causing organophosphorus-induced delayed neuropathy) and acutely neurotoxic OPs (i.e., those highly capable of inhibiting AChE). In these experiments, concentration-response data indicated that the capability to inhibit AChE was over 100x greater than the capability to inhibit NTE for acutely toxic, nonneuropathic OPs (e.g., paraoxon and malaoxon) in both cell lines. Inhibition of AChE was greater than inhibition of NTE, without overlap of the concentration-response curves, for OPs which are more likely to cause acute, rather than delayed, neurotoxic effects in vivo (e.g., chlorpyrifos-oxon, dichlorvos, and trichlorfon). In contrast, concentrations inhibiting AChE and NTE overlapped for neuropathy-causing OPs. For example, apparent IC50 values for NTE inhibition were less than 9.6-fold the apparent IC50 values for AChE inhibition when cells were exposed to the neuropathy-inducing OPs diisopropyl phosphorofluoridate, cyclic tolyl saligenin phosphate, phenyl saligenin phosphate, mipafox, dibutyl dichlorovinyl phosphate, and di-octyl-dichlorovinyl phosphate. In all cases, esterase inhibition occurred at lower concentrations than those needed for cytoxicity. These results suggest that either mouse or human neuroblastoma cell lines can be considered useful in vitro models to distinguish esterase-inhibiting OP neurotoxicants.


Multiexon deletions in the type I collagen COL1A2 gene in osteogenesis imperfecta type IB. Molecules containing the shortened alpha2(I) chains show differential incorporation into the bone and skin extracellular matrix.
Osteogenesis imperfecta (OI) type IB is a rare subset of the mildest form of OI, clinically characterized by moderate bone fragility, blue sclera, and dentinogenesis imperfecta. Cultured skin fibroblasts from two unrelated individuals (OI-197 and OI-165) with the typical features of OI type IB produced shortened alpha2(I) chains. Reverse transcription-polymerase chain reaction of the alpha2(I)-cDNA revealed deletions in the triple helical domain of 5 exons (exons 7-11) in OI-197, and 8 exons (exons 10-17) in OI-165. This exon skipping was caused by genomic deletions in one allele of COL1A2 with the breakpoints located in introns 6 and 11 in OI-197, and introns 9 and 17 in OI-165. The secretion and deposition of the mutant collagen into the matrix was measured in vitro in cultures of skin fibroblasts and bone osteoblasts, grown in the presence of ascorbic acid to induce collagen matrix formation and maturation, as well as in collagen extracts from skin and bone. The secretion of mutant collagen was impaired and long term cultures of fibroblasts showed that the mutant collagen was not incorporated into the mature collagenous matrix produced in vitro by skin fibroblasts from both patients. Likewise, the shortened alpha2(I) chain was not demonstrable in skin extracts. In contrast, bone extracts from OI-197 showed the presence of the mutant collagen. This incorporation of the abnormal collagen into the mature matrix was also demonstrated in long term cultures of the patient's osteoblasts. The deposition of the mutant collagen by bone osteoblasts but not by skin fibroblasts demonstrates a tissue specificity in the incorporation of mutant collagen into the matrix which may explain the primary involvement of bone and not skin in these patients.


Transcription of the muscle regulatory gene Myf4 is regulated by serum components, peptide growth factors and signaling pathways involving G proteins.
The muscle regulatory protein myogenin accumulates in differentiating muscle cells when the culture medium is depleted for serum. To investigate the regulation of myogenin gene expression, we have isolated and characterized the Myf4 gene which encodes the human homologue of murine myogenin. Serum components, basic FGF (b-FGF), transforming growth factor beta (TGF-beta), and EGF, agents which suppress differentiation of muscle cells in vitro, down-regulate the activity of the Myf4 gene, suggesting that it constitutes a nuclear target for the negative control exerted by these factors. The 5' upstream region containing the Myf4 promoter confers activity to a CAT reporter plasmid in C2C12 myotubes but not in fibroblasts and undifferentiated myoblasts. Unidirectional 5' deletions of the promoter sequence reveal that integral of 200 nucleotides upstream of the transcriptional start site are sufficient for cell type-specific expression. The forced expression of the muscle determining factors, MyoD1, Myf5, and Myf6 and to a lesser degree Myf4, results in the transactivation of the Myf4 promoter in C3H mouse 10T1/2 fibroblasts. Pathways potentially involved in conveying signals from the cell-surface receptors to the Myf4 gene were probed with pertussis- and cholera toxin, forskolin, and cAMP. Dibutyryl-cAMP and compounds that stimulate adenylate cyclase inhibit the endogenous Myf4 gene and the Myf4 promoter in CAT and LacZ reporter constructs. Conversely, pertussis toxin which modifies Gi protein stimulates Myf4 gene expression. In summary, our data provide evidence that the muscle-specific expression of the Myf4 gene is subject to negative control by serum components, growth factors and a cAMP-dependent intracellular mechanism. Positive control is exerted by a pertussis toxin-sensitive pathway that presumably involves G proteins.


Production of hemopexin by TNF-alpha stimulated human mesangial cells.
Plasma hemopexin has been shown to induce proteinuria after intrarenal infusion in rats, as well as glomerular alterations identical to those seen in corticosteroid-responsive nephrotic syndrome (CRNS). The question emerged whether also renal cells are potentially able to release hemopexin. Normal human mesangial cells (HMC) were incubated overnight in serum-free medium with or without tumor necrosis factor-alpha (TNF-alpha) (10 ng/mL). Parallel cultures were supplemented with prednisolone (10-3 mol/L). Concentrated supernatants were analyzed by Western blotting, using antihemopexin immunoglobulin G (IgG). Antitransferrin IgG served as control antibody. In addition, cytospins were stained using polyclonal or monoclonal antihemopexin IgG. A part of the cells was used for RNA isolation and reverse transcription-polymerase chain reaction (RT-PCR), to study hemopexin mRNA. Eighty five kD bands were exclusively detected by antihemopexin IgG in the Western blots in supernatants from TNF-alpha-stimulated cultures and to a lesser extent in prednisolone-treated cultures. Cells from TNF-alpha-stimulated cultures stain positive for hemopexin in contrast to those from prednisolone-treated or nonstimulated cultures. RT-PCR data suggest that mRNA for hemopexin is up-regulated in TNF-alpha-treated versus prednisolone-treated HMC. Stimulated HMC are able to release hemopexin in vitro in a corticosteroid-dependent manner. As preliminary data indicate that mesangial hemopexin is able to affect glomerular anionic sites, it is conceivable that stimulated mesangium may contribute to enhanced glomerular permeability in CRNS through local hemopexin release.


Microfluidic Systems with Embedded Cell Culture Chambers for High-Throughput Biological Assays.
The ability to generate chemical and mechanical gradients on chips is important for either creating biomimetic designs or enabling high-throughput assays. However, there is still a significant knowledge gap in the generation of mechanical and chemical gradients in a single device. In this study, we developed gradient-generating microfluidic circuits with integrated microchambers to allow cell culture and to introduce chemical and mechanical gradients to cultured cells. A chemical gradient is generated across the microchambers, exposing cells to a uniform concentration of drugs. The embedded microchamber also produces a mechanical gradient in the form of varied shear stresses induced upon cells among different chambers as well as within the same chamber. Cells seeded within the chambers remain viable and show a normal morphology throughout the culture time. To validate the effect of different drug concentrations and shear stresses, doxorubicin is flowed into chambers seeded with skin cancer cells at different flow rates (from 0 to 0.2 μL/min). The experimental results show that increasing doxorubicin concentration (from 0 to 30 μg/mL) within chambers not only prohibits cell growth but also induces cell death. In addition, the increased shear stress (0.005 Pa) at high flow rates poses a synergistic effect on cell viability by inducing cell damage and detachment. Moreover, the ability of the device to seed cells in a 3D microenvironment was also examined and confirmed. Collectively, the study demonstrates the potential of microchamber-embedded microfluidic gradient generators in 3D cell culture and high-throughput drug screening.


The impact of solvents on the singlet and triplet states of selected fluorine corroles - absorption, fluorescence, and optoacoustic studies.
This paper examines the influence of aprotic solvents on the spectroscopic properties as well as the energy deactivation of two free-base corrole dyes substituted with C6F5 and/or 4-NO2C6H4 groups. Absorption, fluorescence and laser-induced optoacoustic spectroscopy have been used to follow the singlet and triplet states of fluorine corroles belonging to the A2B and A3 type in toluene (TL), chloroform (CL), dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and also in solvent mixtures. Changes in the absorption and fluorescence spectra are influenced by the type of solvent mixture. The fluorescence behaviors of the two investigated corroles were extremely different - fluorescence of the nitro-corrole in TL is dramatically quenched in the presence of DMF. In contrast, fluorescence quenching of fluorine corroles in DMF-TL mixtures is substantially weakened. Absorption, fluorescence, triplet population as well as singlet oxygen generation parameters are evaluated. The spectral experimental data are supported by quantum chemical calculations - time-dependent density functional theory (TD-DFT) and cyclic voltammetry experiments. The presented results are discussed from a viewpoint of aggregation, tautomerization, and deprotonation effects occurring in the corroles.


Helminths of the Lizard Salvator merianae (Squamata, Teiidae) in the Caatinga, Northeastern Brazil.
The lizard Salvator merianae is a widely distributed species in South America, occurring from southern Amazonia to the eastern Andes and northern Patagonia. Studies on the parasitic fauna of this lizard have revealed that it is a host for helminths in various Brazilian biomes. The present work provides new parasitological data on the gastrointestinal nematodes associated with the lizard S. merianae. Sixteen specimens were analyzed from nine different locations in a semi-arid region in northeastern Brazil. Five species of nematodes were identified. Oswaldofilaria petersi was first recorded as a parasite of the S. merianae, thus increasing the knowledge of the fauna of parasites that infect large Neotropical lizards.


Genome-wide localization of exosome components to active promoters and chromatin insulators in Drosophila.
Chromatin insulators are functionally conserved DNA-protein complexes situated throughout the genome that organize independent transcriptional domains. Previous work implicated RNA as an important cofactor in chromatin insulator activity, although the precise mechanisms are not yet understood. Here we identify the exosome, the highly conserved major cellular 3' to 5' RNA degradation machinery, as a physical interactor of CP190-dependent chromatin insulator complexes in Drosophila. Genome-wide profiling of exosome by ChIP-seq in two different embryonic cell lines reveals extensive and specific overlap with the CP190, BEAF-32 and CTCF insulator proteins. Colocalization occurs mainly at promoters but also boundary elements such as Mcp, Fab-8, scs and scs', which overlaps with a promoter. Surprisingly, exosome associates primarily with promoters but not gene bodies of active genes, arguing against simple cotranscriptional recruitment to RNA substrates. Similar to insulator proteins, exosome is also significantly enriched at divergently transcribed promoters. Directed ChIP of exosome in cell lines depleted of insulator proteins shows that CTCF is required specifically for exosome association at Mcp and Fab-8 but not other sites, suggesting that alternate mechanisms must also contribute to exosome chromatin recruitment. Taken together, our results reveal a novel positive relationship between exosome and chromatin insulators throughout the genome.


Sleep ontogenesis revisited: a longitudinal 24-hour home polygraphic study on 15 normal infants during the first two years of life.
The sleep organization of 15 normal infants (seven boys, eight girls) was studied at their homes during six 24-hour periods, i.e. at 3, 6, 9, 12, 18, and 24 months of age, using the Oxford Medical System. Sleep states and stages were scored visually at 30-second intervals, according to Rechtschaffen and Kales' criteria, adapted for children by Guilleminault. All sleep parameters were analyzed for the entire 24-hour period, i.e. during both the nocturnal and the diurnal part of the nycthemere. The results showed a continuous decrease in total sleep time, rapid eye movement (REM) sleep, and indeterminate sleep, and also an increase in waking time, quiet sleep, and stages 1 and 2 sleep. Except for slow-wave sleep, which remained very stable for the different ages, analysis of variance applied to the data showed clear age and day-night effects on sleep ontogenesis. Modifications with age were more precocious and more pronounced for the diurnal part of the nycthemere, especially as regards REM sleep. For the nocturnal part, there was a significant increase in sleep efficiency and in the length of the REM period after 12 months of age, while total sleep duration and number of awakenings decreased. In addition to normative data for clinical use, this study provides three new interesting results related to the maturation of sleep mechanisms and functions: 1) the high stability of the percentage of slow-wave sleep along these 2 years, 2) the presence (from 12 months of age) of a stage 2/REM sleep ratio equal to one, and a sleep change occuring earlier, during the diurnal rather than the nocturnal part of the nycthemere. The first two points could be regarded as indexes of sleep maturation reflecting developmental and neurophysiological changes in central nervous system structures. The third point underlines the importance of the circadian rhythm and the concept of "experience" in the maturation of sleep.


"Retweet to Pass the Blunt": Analyzing Geographic and Content Features of Cannabis-Related Tweeting Across the United States.
Twitter data offer new possibilities for tracking health-related communications. This study is among the first to apply advanced information processing to identify geographic and content features of cannabis-related tweeting in the United States. Tweets were collected using streaming Application Programming Interface (March-May 2016) and were processed by eDrugTrends to identify geolocation and classify content by source (personal communication, media, retail) and sentiment (positive, negative, neutral). States were grouped by cannabis legalization policies into "recreational," "medical, less restrictive," "medical, more restrictive," and "illegal." Permutation tests were performed to analyze differences among four groups in adjusted percentages of all tweets, unique users, personal communications only, and positive-to-negative sentiment ratios. About 30% of all 13,233,837 cannabis-related tweets had identifiable state-level geo-information. Among geolocated tweets, 76.2% were personal communications, 21.1% media, and 2.7% retail. About 71% of personal communication tweets expressed positive sentiment toward cannabis; 16% expressed negative sentiment. States in the recreational group had significantly greater average adjusted percentage of cannabis tweets (3.01%) compared with other groups. For personal communication tweets only, the recreational group (2.47%) was significantly greater than the medical, more restrictive (1.84%) and illegal (1.85%) groups. Similarly, the recreational group had significantly greater average positive-to-negative sentiment ratio (4.64) compared with the medical, more restrictive (4.15) and illegal (4.19) groups. Average adjusted percentages of unique users showed similar differences between recreational and other groups. States with less restrictive policies displayed greater cannabis-related tweeting and conveyed more positive sentiment. The study demonstrates the potential of Twitter data to become a valuable indicator of drug-related communications in the context of varying policy environments.


5-Hydroxytryptophan versus methysergide in the prophylaxis of migraine. Randomized clinical trial.
One hundred and twenty-four migraineurs were treated randomly with 5-hydroxytryptophan (5-HTP) or with methysergide (M). The two groups were homogeneous without significant statistical differences with respect to age, sex, pill use, type of migraine and frequency of attacks before entry. A significant improvement was observed in 75% of the patients treated with M and in 71% of the cases treated with 5-HTP. The most beneficial effect of 5-HTP appears to be felt with regard to the intensity and duration rather than the frequency of the attacks. Side effects were more frequent in the M group than in the 5-HTP group. These results suggest that 5-HTP could be a treatment of choice in the prophylaxis of migraine.


Late effects in ankylosing spondylitis patients treated with 224Ra.
This study is comprised of 1577 ankylosing spondylitis patients from 9 German hospitals who have been treated with multiple injections of (224)Ra. The majority of the patients, most of them treated in the years 1948-1975, received one series of 10 weekly intravenous injections of about 1 MBq of (224)Ra each. This dose leads to a mean absorbed dose due to alpha-particle radiation of 0.56 Gy to the marrow-free skeleton of a 70- kg man (mean bone surface dose of about 5 Gy). To provide comparative information on causes of death and on health effects possibly related to the basic disease itself, a control group of 1462 ankylosing spondylitis patients with roughly the same age distribution has been established. By the end of 1998, 649 patients in the exposed group and 762 control patients had died. Among other observations, it is of particular interest that 13 cases of leukemia in the exposed group have been observed. This is a highly significant excess (P < 0.001) compared to a standard population, but only a marginally significant excess in comparison to the seven cases observed in the control group. Subclassification of the leukemias shows a clear preponderance of the myeloid leukemias in the exposed group (8 cases observed compared to 1.7 cases expected, P < 0.001), whereas in the control group the observed cases are within the expected range for myeloid leukemia (3 cases observed compared to 2.2 cases expected, P = 0.3). The (224)Ra cohort of the earlier study (higher-dose group) has provided a risk coefficient that predicts about 8 excess malignant bone tumors for the irradiated cohort in this study. In actuality, 4 cases of malignant tumors in the skeleton have been observed so far. However, excess of breast cancer has not been observed in either the irradiated or the control group, which is in contrast to the findings in the earlier (224)Ra cohort of Study I.


The impact of topical agents and dressing on pH and temperature on wound healing: A systematic, narrative review.
To assess the impact of topical agents and dressings on surface wound pH, temperature, and subsequent wound healing. This was a systematic, narrative review of the literature, following the PRISMA (2020) guidelines. The databases searched were Medline PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Embase, Web of Science, and Scopus. Data synthesis and analysis were conducted using a structured narrative synthesis. The quality of the included clinical studies was appraised using the Evidence-Based Literature (EBL) Critical Appraisal Tool. A total of six clinical studies were assessed as eligible for inclusion, A total of six dressings/topical agents were assessed and the types of wounds included non-healing chronic wounds. Of the studies, five explored pH and one explored temperature. The EBL validity of the clinical studies was low (mean quality score was 51.3%). The five clinical studies that explored pH investigated different dressings and topical agents reporting an associated reduction in pH and improved wound outcomes. One clinical study investigated the impact of topical sodium nitrite on temperature and found that sodium nitrite increased peri-wound skin temperature and improved wound outcomes with a reduction in leg ulcer size. Given the low certainty of the evidence, we cannot confidently recommend the use of any particular topical agent or dressing to manipulate pH, or temperature to improve wound outcomes. Thus, there is a need for further research to develop a greater understanding of this topic. Irish Research Council, Enterprise Partnership Scheme.


Protein matrices for improved wound healing: elastase inhibition by a synthetic peptide model.
The unique properties of silk fibroin were combined with keratin to develop new wound-dressing materials. Silk fibroin/keratin (SF/K) films were prepared to reduce high levels of elastase found on chronic wounds. This improved biological function was achieved by the incorporation of a small peptide synthesized based on the reactive-site loop of the Bowman-Birk Inhibitor (BBI) protein. In vitro degradation and release were evaluated using porcine pancreatic elastase (PPE) solution as a model of wound exudate. It was found that biological degradation and release rate are highly dependent on film composition. Furthermore, the level of PPE activity can be tuned by changing the film composition, thus showing an innovative way of controlling the elastase-antielastase imbalance found on chronic wounds.


Various effects of the expression of the xyloglucanase gene from Penicillium canescens in transgenic aspen under semi-natural conditions.
Recombinant carbohydrases genes are used to produce transgenic woody plants with improved phenotypic traits. However, cultivation of such plants in open field is challenging due to a number of problems. Therefore, additional research is needed to alleviate them. Results of successful cultivation of the transgenic aspens (Populus tremula) carrying the recombinant xyloglucanase gene (sp-Xeg) from Penicillium canescens in semi-natural conditions are reported in this paper for the first time. Change of carbohydrate composition of wood was observed in transgenic aspens carrying the sp-Xeg gene. The transformed transgenic line Xeg-2-1b demonstrated accelerated growth and increased content of cellulose in wood of trees growing in both greenhouse and outside in comparison with the control untransformed line Pt. The accelerated growth was observed also in the transgenic line Xeg-1-1c. Thicker cell-wall and longer xylem fiber were also observed in both these transgenic lines. Undescribed earlier considerable reduction in the wood decomposition rate of the transgenic aspen stems was also revealed for the transformed transgenic lines. The decomposition rate was approximately twice as lower for the transgenic line Xeg-2-3b in comparison with the control untransformed line Pt. A direct dependence of the phenotypic and biochemical traits on the expression of the recombinant gene sp-Xeg was demonstrated. The higher was the level of the sp-Xeg gene expression, the more pronounced were changes in the phenotypic and biochemical traits. All lines showed phenotypic changes in the leave traits. Our results showed that the plants carrying the recombinant sp-Xeg gene do not demonstrate a decrease in growth parameters in semi-natural conditions. In some transgenic lines, a change in the carbohydrate composition of the wood, an increase in the cell wall thickness, and a decrease in the rate of decomposition of wood were observed.


Association among growth, food consumption-related traits and amylase gene polymorphism in the Pacific oyster Crassostrea gigas.
To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of alpha-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy budget model, showed that observed ingestion rates (unlike absorption efficiencies) allowed an accurate prediction of growth potential in these genotypes. The observed association between growth and amylase gene polymorphism is therefore more likely to be related to ingestion than to absorption efficiency. Additionally, relative mRNA levels of the two amylase cDNAs were also strongly associated with amylase gene polymorphism, possibly reflecting variation in an undefined regulatory region, although no corresponding variation was observed in specific amylase activity. Amylase gene sequences were determined for each genotype, showing the existence of only synonymous or functionally equivalent non-synonymous polymorphisms. The observed associations among growth, food consumption-related traits and amylase gene polymorphism are therefore more likely to be related to variation in the level of amylase gene expression than to functional enzymatic variants.


In situ effect of a dentifrice with low fluoride concentration and low pH on enamel remineralization and fluoride uptake.
Since the anticaries effect of a dentifrice with low fluoride concentration and low pH is unknown, the aim of the present study was to evaluate in situ the enamel remineralizing ability of this type of formulation. A double-blind crossover design employing 3 phases of 45 days was conducted. Six adult volunteers wore palatal devices containing 6 previously demineralized human dental enamel slabs, which were subjected 3 times a day to one of the following treatments: non-fluoridated dentifrice (negative control); dentifrice containing 1, 100 microg F/g, pH 7.0 (positive control); dentifrice containing 550 microg F/g, pH 5.5 (experimental). At the end of each phase, enamel remineralization was assessed in terms of cross-sectional microhardness, and loosely as well as firmly bound fluoride formation was determined on the enamel surface. Fluoridated dentifrices were more effective than the negative control in forming loosely and firmly bound fluoride on enamel (P < 0.05). However, the positive control formed more loosely bound fluoride than the other treatments (P < 0.05). Microhardness analysis showed that the fluoridated dentifrices were more effective than the negative control (P < 0.05) in remineralizing dental enamel, although no statistically significant difference was observed between them. Thus, the experimental dentifrice was shown to be effective in remineralizing dental enamel, and this may be attributable to its ability to form firmly bound fluoride on enamel.


Design of a randomized clinical trial of a colorectal cancer screening decision aid to promote appropriate screening in community-dwelling older adults.
Appropriate colorectal cancer screening in older adults should be aligned with the likelihood of net benefit. In general, patient decision aids improve knowledge and values clarity, but in older adults, they may also help patients identify their individual likelihood of benefit and foster individualized decision-making. We report on the design of a randomized clinical trial to understand the effects of a patient decision aid on appropriate colorectal cancer screening. This report includes a description of the baseline characteristics of participants. English-speaking primary care patients aged 70-84 years who were not currently up to date with screening were recruited into a randomized clinical trial comparing a tailored colorectal cancer screening decision aid with an attention control. The intervention group received a decision aid that included a values clarification exercise and individualized decision-making worksheet, while the control group received an educational pamphlet on safe driving behaviors. The primary outcome was appropriate screening at 6 months based on chart review. We used a composite measure to define appropriate screening as screening for participants in good health, a discussion about screening for patients in intermediate health, and no screening for patients in poor health. Health state was objectively determined using patients' Charlson Comorbidity Index score and age. A total of 14 practices in central North Carolina participated as part of a practice-based research network. In total, 424 patients were recruited to participate and completed a baseline visit. Overall, 79% of participants were White and 58% female, with a mean age of 76.8 years. Patient characteristics between groups were similar by age, gender, race, education, insurance coverage, or work status. Overall, 70% had some college education or more, 57% were married, and virtually all had Medicare insurance (90%). The three primary medical conditions among the cohort were a history of diabetes, pneumonia, and cancer (28%, 26%, and 21%, respectively). We designed a randomized clinical trial to test a novel use of a patient decision aid to promote appropriate colorectal cancer screening and have recruited a diverse study population that seems similar between the intervention and control groups. The study should be able to determine the ability of a patient decision aid to increase individualized and appropriate colorectal cancer screening.


Gas chromatographic method using photoionization detection for the determination of breath pentane.
Lipid peroxidation is thought to be an important event in the pathogenesis of atherosclerosis. It has been suggested that pentane, which can be formed during the oxidation of omega-6 fatty acids, is a marker of lipid peroxidation. Previous studies have reported elevated breath pentane and serum markers of lipid peroxidation in smokers. However, chromatographic separation of pentane from isoprene in virtually all of these studies was incomplete and the methods used did not resolve pentane into its isomers, n-pentane and isopentane. Additionally, most current methods are complicated, requiring trapping and concentrating steps to obtain adequate sensitivity prior to hydrocarbon analysis. The purpose of the current study was to develop a gas chromatographic system to analyze breath pentane, that addresses the above technical problems and that would provide a simple in vivo method for measuring lipid. n-Pentane and isopentane standards were easily separated from isoprene with a Al2O3/KCI capillary column contained in a portable gas chromatograph equipped with a photoionization detector. The analysis of repeated measures showed a low coefficient of variation for measurements of n-pentane (10%) and isopentane (9%). We measured breath pentane in 27 subjects (15 smokers, 12 non-smokers). There were no significant difference between the baseline and 4 week interval measurements of n-pentane for smokers both before and after cigarette smoking. The within-subject variability data showed that the assay is highly reproducible for both low and high pentane levels in smokers. Smokers were found to have higher levels of both n-pentane and isopentane than non-smokers (P < 0.001). In addition, smokers had further significant elevation of pentane levels 10 min after smoking (P < 0.001), which returned to baseline by 1 h. These studies demonstrate that measurement of breath pentane, using a gas chromatograph with a photoionization detector, is simple and reproducible. Additionally, these results suggest that pentane elevation associated with smoking is secondary to the oxidant effects of cigarette smoke and an important temporal relationship exists between cigarette smoking and breath sample analysis.


Impact of simulation training on time to initiation of cardiopulmonary resuscitation for first-year pediatrics residents.
Pediatrics residents have few opportunities to perform cardiopulmonary resuscitation (CPR). Enhancing the quality of CPR is a key factor to improving outcomes for cardiopulmonary arrest in children and requires effective training strategies. To evaluate the effectiveness of a simulation-based intervention to reduce first-year pediatrics residents' time for 3 critical actions in CPR: (1) call for help, (2) initiate bag-mask ventilation, and (3) initiate chest compressions. A prospective study involving 31 first-year pediatrics residents at a children's hospital assigned to an early or late (control) intervention group. Residents underwent baseline assessment followed by repeat evaluations at 3 and 6 months. Time to critical actions was scored by video review. A 90-minute educational intervention focused on skill practice was conducted following baseline evaluation for the early-intervention group and following 3-month evaluation for the late-intervention group. Primary outcome was change in time to initiating the 3 critical actions. Change in time was analyzed by comparison of Kaplan-Meier curves, using the log-rank test. A 10% sample was timed by a second rater. Agreement was assessed using intraclass correlation (ICC). There was a statistically significant reduction in time for all 3 critical actions between baseline and 3-month evaluation in the early intervention group; this was not observed in the late (control) group. Rater agreement was excellent (ICC ≥ 0.99). A simulation-based educational intervention significantly reduced time to initiation of CPR for first-year pediatrics residents. Simulation training facilitated acquisition of critical CPR skills that have the potential to impact patient outcome.


The Error in "Error Rate": Why Error Rates Are So Needed, Yet So Elusive.
Establishing error rates is crucial for knowing how well one is performing, determining whether improvement is needed, measuring whether interventions are effective, as well as for providing transparency. However, the flurry of activities in establishing error rates for the forensic sciences has largely overlooked some fundamental issues that make error rates a problematic construct and limit the ability to obtain a meaningful error rate. These include knowing the ground truth, establishing appropriate databases, determining what counts as an error, characterizing what is an acceptable error rate, ecological validity, and transparency within the adversarial legal system. Without addressing these practical and theoretical challenges, the very notion of a meaningful error rate is limited.


Protein kinase A directly phosphorylates metabotropic glutamate receptor 5 to modulate its function.
Metabotropic glutamate receptor 5 (mGluR5) regulates excitatory post-synaptic signaling in the central nervous system (CNS) and is implicated in various CNS disorders. Protein kinase A (PKA) signaling is known to play a critical role in neuropsychiatric disorders such as Parkinson's disease, schizophrenia, and addiction. Dopamine signaling is known to modulate the properties of mGluR5 in a cAMP- and PKA-dependent manner, suggesting that mGluR5 may be a direct target for PKA. Our study identifies mGluR5 at Ser870 as a direct substrate for PKA phosphorylation and demonstrates that this phosphorylation plays a critical role in the PKA-mediated modulation of mGluR5 functions such as extracellular signal-regulated kinase phosphorylation and intracellular Ca(2+) oscillations. The identification of the molecular mechanism by which PKA signaling modulates mGluR5-mediated cellular responses contributes to the understanding of the interaction between dopaminergic and glutamatergic neuronal signaling. We identified serine residue 870 (S870) in metabotropic glutamate receptor 5 (mGluR5) as a direct substrate for protein kinase A (PKA). The phosphorylation of this site regulates the ability of mGluR5 to induce extracellular signal-regulated kinase (ERK) phosphorylation and intracellular Ca(2+) oscillations. This study provides a direct molecular mechanism by which PKA signaling interacts with glutamate neurotransmission.


Toxocariasis of the central nervous system: with report of two cases.
Clinical involvement of the nervous system in visceral larva migrans due to Toxocara is rare, although in experimental animals the larvae frequently migrate to the brain. A review of the literature from the early 50's to date found 29 cases of brain involvement in toxocariasis. In 20 cases, various clinical and laboratory manifestations of eosinophilic meningitis, encephalitis, myelitis or radiculopathy were reported. We report two children with neurological manifestations, in which there was cerebrospinal fluid pleocytosis with marked eosinophilia and a positive serology for Toxocara both in serum and CSF. Serology for Schistosoma mansoni, Cysticercus cellulosae, Toxoplasma and cytomegalovirus were negative in CSF, that was sterile in both cases. Improvement of signs and symptoms after specific treatment (albendazole or thiabendazole) was observed in the two cases. A summary of data described in the 25 cases previously reported is presented and we conclude that in cases of encephalitis and myelitis with cerebrospinal fluid pleocytosis and eosinophilia, parasitic infection of the central nervous system should be suspected and serology should be performed to establish the correct diagnosis and treatment.


Effects of Corynebacterium granulosum on weight and histology of lymphoid organs, response to mitogens, skin allografts, and a syngeneic fibrosarcoma in mice.
We studied the effect of single and multiple injections of Corynebacterium granulosum on weight and histology of lymph nodes and spleen, on peripheral white blood cell count, response of peripheral blood lymphocytes, lymph node, and spleen cells to phytohemagglutinin and pokeweed mitogen, survival of skin allografts, and lung metastases of a syngeneic fibrosarcoma in C3Hf/Bu mice. Corynebacterium parvum was used in some studies on antitumor activity. The weight of lymph nodes and spleen was markedly increased by single and multiple i.p. injections of C. granulosum, the peak enlargement occurring at Day 7 in lymph nodes and at Day 16 in spleen. Histologically, there was an extensive proliferation of nucleated cells in the enlarged organs. C. granulosum did not change the total white blood cell count but caused a temporary lymphopenia. In general, in vitro response to phytohemagglutinin and pokeweed mitogen of blood lymphocytes and spleen cells was decreased. Lymph node cell response to phytohemagglutinin was increased by small doses (0.025 mg) of C. granulosum, was not altered by a single large dose (0.5 mg), and was decreased by multiple doses. The response of lymph node cells to pokeweed mitogen was increased by all treatments. These changes in response to mitogens were demonstrable for about 2 months after treatment. Treatment i.v. with 0.1 or 0.25 mg of C. granulosum given before but not after grafting significantly prolonged the survival of grafted BALB/c skin. Smaller doses of this bacterium were not effective. Splenectomy of skin graft recipients did not prevent the effect of C. granulosum. Treatment i.p. or i.v. with this bacterium significantly decreased the number of lung metastases from i.v.-injected fibrosarcoma cells, even if the cells were injected 3 to 4 months later. The magnitude of this effect varied with the dose and frequency of injection of C. granulosum and C. parvum.


Pyridaben impaired cell cycle progression through perturbation of calcium homeostasis and PI3K/Akt pathway in zebrafish hepatocytes.
Environmental pollution caused by pesticides is a growing concern. Pyridaben, a widely used organochlorine insecticide, is a representative water pollutant. Owing to its extensive usage, it has been detected in various aquatic ecosystems, including rivers and oceans. Pyridaben is highly toxic to aquatic organisms; however, the mechanism of its toxicity in the liver, which is important in toxicant metabolism, has not been studied. Therefore, we employed zebrafish and its well-characterized liver cell line, ZFL to assess pyridaben hepatotoxicity and explore its potential mechanisms of action. Pyridaben led to reduction of the liver size and fluorescence intensity of dsRed-labeled Tg (fabp10a:dsRed) zebrafish. It reduced the viability and proliferation of ZFL cells in vitro by inducing apoptosis and cell cycle arrest. These changes might be primarily linked to uncontrolled intracellular calcium flow in ZFL cells exposed to pyridaben. Additionally, it also downregulates the PI3K/Akt signaling cascade, leading to the inactivation of Gsk3β and nuclear translocation of β-catenin. Taken together, our findings suggest that pyridaben could have hepatotoxic effects on aquatic organisms. This study is the first to provide insight into the hepatotoxic mechanism of pyridaben using both in vivo and in vitro models.


Long-term occupational stress is associated with regional reductions in brain tissue volumes.
There are increasing reports of cognitive and psychological declines related to occupational stress in subjects without psychiatric premorbidity or major life trauma. The underlying neurobiology is unknown, and many question the notion that the described disabilities represent a medical condition. Using PET we recently found that persons suffering from chronic occupational stress had limbic reductions in the 5-HT1A receptor binding potential. Here we examine whether chronic work-related stress is also associated with changes in brain structure. We performed MRI-based voxel-based morphometry and structural volumetry in stressed subjects and unstressed controls focusing on gray (GM) and white matter (WM) volumes, and the volumes of hippocampus, caudate, and putamen - structures known to be susceptible to neurotoxic changes. Stressed subjects exhibited significant reductions in the GM volumes of the anterior cingulate cortex and the dorsolateral prefrontal cortex. Furthermore, their caudate and putamen volumes were reduced, and the volumes correlated inversely to the degree of perceived stress. Our results add to previous data on chronic psychosocial stress, and indicate a morphological involvement of the frontostriatal circuits. The present findings of morphological changes in these regions confirm our previous conclusion that symptoms from occupational stress merit careful investigations and targeted treatment.


Wandering through quantum-mechanochemistry: from concepts to reactivity and switches.
Mechanochemistry has experienced a renaissance in recent years witnessing, at the molecular level, a remarkable interplay between theory and experiment. Molecular mechanochemistry has welcomed a broad spectrum of quantum-chemical methods to evaluate the influence of an external mechanical force on molecular properties. In this contribution, an overview is given on recent work on quantum mechanochemistry in the Brussels Quantum Chemistry group (ALGC). The effect of an external force was scrutinized both in fundamental topics, like reactivity descriptors in Conceptual DFT, and in applied topics, such as designing molecular force probes and tuning the stereoselectivity of certain types of reactions. In the conceptual part, a brief overview of the techniques introducing mechanical forces into a quantum-mechanical description of a molecule is followed by an introduction to conceptual DFT. The evolution of the electronic chemical potential (or electronegativity), chemical hardness and electrophilicity are investigated when a chemical bond in a series of diatomics is put under mechanical stress. Its counterpart, the influence of mechanical stress on bond angles, is analyzed by varying the strain present in alkyne triple bonds by applying a bending force, taking the strain promoted alkyne-azide coupling cycloaddition as an example. The increase of reactivity of the alkyne upon bending is probed by Fukui functions and the local softness. In the applied part, a new molecular force probe is presented based on an intramolecular 6π-electrocyclization in constrained polyenes operating under thermal conditions. A cyclic process is conceived where ring opening and closure are triggered by applying or removing an external pulling force. The efficiency of mechanical activation strongly depends on the magnitude of the applied force and the distance between the pulling points. The idea of pulling point distances as a tool to identify new mechanochemical processes is then tested in [28]hexaphyrins with an intricate equilibrium between Möbius aromatic and Hückel antiaromatic topologies. A mechanical force is shown to trigger the interconversion between the two topologies, using the distance matrix as a guide to select appropriate pulling points. In a final application, the Felkin-Anh model for the addition of nucleophiles to chiral carbonyls under the presence of an external mechanical force is scrutinized. By applying a force for restricting the conformational freedom of the chiral ketone, otherwise inaccessible reaction pathways are promoted on the force-modified potential energy surfaces resulting in a diastereoselectivity different from the force-free reaction.


Machine learning algorithms for systematic review: reducing workload in a preclinical review of animal studies and reducing human screening error.
Here, we outline a method of applying existing machine learning (ML) approaches to aid citation screening in an on-going broad and shallow systematic review of preclinical animal studies. The aim is to achieve a high-performing algorithm comparable to human screening that can reduce human resources required for carrying out this step of a systematic review. We applied ML approaches to a broad systematic review of animal models of depression at the citation screening stage. We tested two independently developed ML approaches which used different classification models and feature sets. We recorded the performance of the ML approaches on an unseen validation set of papers using sensitivity, specificity and accuracy. We aimed to achieve 95% sensitivity and to maximise specificity. The classification model providing the most accurate predictions was applied to the remaining unseen records in the dataset and will be used in the next stage of the preclinical biomedical sciences systematic review. We used a cross-validation technique to assign ML inclusion likelihood scores to the human screened records, to identify potential errors made during the human screening process (error analysis). ML approaches reached 98.7% sensitivity based on learning from a training set of 5749 records, with an inclusion prevalence of 13.2%. The highest level of specificity reached was 86%. Performance was assessed on an independent validation dataset. Human errors in the training and validation sets were successfully identified using the assigned inclusion likelihood from the ML model to highlight discrepancies. Training the ML algorithm on the corrected dataset improved the specificity of the algorithm without compromising sensitivity. Error analysis correction leads to a 3% improvement in sensitivity and specificity, which increases precision and accuracy of the ML algorithm. This work has confirmed the performance and application of ML algorithms for screening in systematic reviews of preclinical animal studies. It has highlighted the novel use of ML algorithms to identify human error. This needs to be confirmed in other reviews with different inclusion prevalence levels, but represents a promising approach to integrating human decisions and automation in systematic review methodology.


[Signaling pathways involved in megakaryopoiesis].
Hematotoxicology has been studied with less interest than other fields associated with atmospheric pollution. There is limited knowledge about on the effects that certain atmospheric pollutants may provoke in the blood and bone marrow. Suspended particle pollution has become an area of scientific inquiry due to the contaminants adhering to its surface. We have identified the association of inhaled vanadium and variations in megakaryopoyesis and thrombopoyesis. Platelets are the smallest elements in the blood, but they play a strategic role in hemostasis. They are derived from the largest cell of the bone marrow, the megakaryocite. This cell size is about 150 microm, with apolyploid nucleus and unknown origin until few years ago. When TPO was cloned in 1994 the knowledge about megakaryocyte began to growth exponentially, elucidating the mechanisms of proliferation, differentiation and release of platelets. More information is still needed in order to translate knowledge into clinical application for diseases such as thrombocytopenia or thrombocytosis. A review of the current concepts of megakaryopoiesis and its regulation, with emphasis on signaling pathways are presented in this paper; a classification in TPO-dependent and TPO-independent is also detailed. In addition, we review some diseases associated with changes in the signaling pathway of megakaryopoyesis, as well as possible perspectives in this field, including toxicology.


Human adenovirus infection in children with acute respiratory tract disease in Guangzhou, China.
Acute respiratory infections (ARI) are the major worldwide health problem due to associated high morbidity and mortality rates. Adenovirus (Adv) is one of the most common causes of viral ARI, and thus calls for specific diagnosis and better understanding of the epidemiology and clinical characteristics. Our aims were to find out the status of Adv infection in children <14 years with ARI, analyze the epidemiology and clinical characteristics among the Adv-infected children in Guangzhou, China, and to provide some basis for the research of Adv. The throat and pharyngeal swabs were collected among the children with acute respiratory tract infections in outpatient department from September 2006 to August 2008. The samples were analyzed by PCR and the sequences were blasted with the sequences of Adv in GenBank. Clinical data were analyzed along with virological data by using appropriate statistical methods. Adv was detected in 25 out of 512 (4.9%) children. The genome types of 23 samples were determined after analysis of the gene sequence. The most prevalent Adv type was species B type 3. Among the patients, 10 were of Ad3 (43.5%), three were of Ad1 (1.3%), five were of species C Ad2 (21.7%), and five were of species E Ad4 (21.7%). A higher incidence of positive results was found during the summer season, thus showing a pattern of seasonality. There exists Adv infection in children with acute respiratory system diseases in Guangzhou area. No significant differences were found among different age groups and gender groups. Co-infections with other respiratory virus were detected in 64% of the Adv positive samples.


Analysis of c-myc expression in a human hepatoma cell line.
A tumorigenic human hepatoma cell line, Hep G2, has been shown to have high steady-state levels of c-myc transcripts compared to normal human liver. We have now characterized c-myc expression in Hep G2 cells with regard to message stability, gene rearrangements, gene amplification, chromosomal translocations, promoter utilization, and the effects of protein synthesis inhibitors. We have determined that the half-life of the Hep G2 c-myc transcript is approximately 20 min and conclude that the high steady-state level of c-myc mRNA is not the result of a specific stabilization of the c-myc message but probably results from increased c-myc gene transcription. c-myc expression in Hep G2 cells appears to be constitutive, since it remains constant in different cell growth states (log phase versus nondividing cells). The high constitutive expression of the c-myc gene in Hep G2 cells could not be explained by gene amplification, gene rearrangements, or chromosomal translocations. However, based on an S1 nuclease protection assay, the P1/P2 promoter utilization ratio is approximately 1/1 which differs from the 1/5 P1/P2 ratio observed in normal human liver. Treatment with cycloheximide, a protein synthesis inhibitor, does not superinduce Hep G2 c-myc transcription based on transcription "run on" and RNA slot blot analysis. However, cycloheximide treatment does exert a posttranscriptional effect involving the specific stabilization of the c-myc message.


Dynamical Localization of DivL and PleC in the Asymmetric Division Cycle of Caulobacter crescentus: A Theoretical Investigation of Alternative Models.
Cell-fate asymmetry in the predivisional cell of Caulobacter crescentus requires that the regulatory protein DivL localizes to the new pole of the cell where it up-regulates CckA kinase, resulting in a gradient of CtrA~P across the cell. In the preceding stage of the cell cycle (the "stalked" cell), DivL is localized uniformly along the cell membrane and maintained in an inactive form by DivK~P. It is unclear how DivL overcomes inhibition by DivK~P in the predivisional cell simply by changing its location to the new pole. It has been suggested that co-localization of DivL with PleC phosphatase at the new pole is essential to DivL's activity there. However, there are contrasting views on whether the bifunctional enzyme, PleC, acts as a kinase or phosphatase at the new pole. To explore these ambiguities, we formulated a mathematical model of the spatiotemporal distributions of DivL, PleC and associated proteins (DivJ, DivK, CckA, and CtrA) during the asymmetric division cycle of a Caulobacter cell. By varying localization profiles of DivL and PleC in our model, we show how the physiologically observed spatial distributions of these proteins are essential for the transition from a stalked cell to a predivisional cell. Our simulations suggest that PleC is a kinase in predivisional cells, and that, by sequestering DivK~P, the kinase form of PleC enables DivL to be reactivated at the new pole. Hence, co-localization of PleC kinase and DivL is essential to establishing cellular asymmetry. Our simulations reproduce the experimentally observed spatial distribution and phosphorylation status of CtrA in wild-type and mutant cells. Based on the model, we explore novel combinations of mutant alleles, making predictions that can be tested experimentally.