Bilateral oophorectomy and the risk of incident diabetes in postmenopausal women.
Ovarian hormones regulate glucose uptake and insulin sensitivity. Despite the high frequency of surgical menopause, its relationship with diabetes has not been extensively investigated. We assessed the association between hysterectomy with or without bilateral oophorectomy (BSO) status, menopausal age, and reproductive life span with incident diabetes. Data were from a cohort of 2,597 postmenopausal women enrolled in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study without diabetes mellitus at baseline. Cox proportional hazards regression models were used to calculate adjusted hazard ratios (HRs) and 95% CIs. After a median follow-up time of 9.2 years, the incidence of diabetes (in cases per 1,000 person-years) was 7.4 for women with no hysterectomy or BSO, 8.2 for hysterectomy alone, and 8.5 for hysterectomy with BSO. Hysterectomy status was associated positively with diabetes (HR 1.66, 95% CI 1.23-2.23). However, the elevated risk was restricted to women with both hysterectomy and BSO after adjustment for relevant confounders (HR 1.57, 95% CI 1.03-2.41). An earlier age at menopause and a shorter reproductive life span also exhibited a linear relationship with the development of diabetes irrespective of type of menopause (P for trend = 0.001). Women with hysterectomy concomitant with BSO may represent a unique population with elevated risk for diabetes and other chronic diseases. Therefore, the decision to remove the ovaries at the time of hysterectomy for benign conditions during the premenopausal years should be balanced with the risk of diabetes and its potential complications. Furthermore, the mechanism linking BSO to diabetes mellitus needs to be clarified.


Fractionating the word repetition effect with event-related potentials.
Word repetition has been a staple paradigm for both psycholinguistic and memory research; several possible loci for changes in behavioral performance have been proposed. These proposals are discussed in light of the event-related brain potential (ERP) data reported here. ERPs were recorded as subjects read nonfiction articles drawn from a popular magazine. The effects of word repetition were examined in this relatively natural context wherein words were repeated as a consequence of normal discourse structure. Three distinct components of the ERP were found to be sensitive to repetition: a positive component peaking at 200 msec poststimulus, a negative one at 400 msec (N400), and a later positivity. The components were differentially sensitive to the temporal lag between repetitions, the number of repetitions, and the normative frequency of the eliciting word. The N400 responded similarly to repetition in text as it has in experimental lists of words, but the late positivity showed a different pattern of results than in list studies.


Definition of the full extent of glycosylation of the 45-kilodalton glycoprotein of Mycobacterium tuberculosis.
Chemical evidence for the true glycosylation of mycobacterial proteins was recently provided in the context of the 45-kDa MPT 32 secreted protein of Mycobacterium tuberculosis (K. Dobos, K. Swiderek, K.-H. Khoo, P. J. Brennan, and J. T. Belisle, Infect. Immun. 63:2846-2853, 1995). However, the full extent and nature of glycosylation as well as the location of glycosylated amino acids remained undefined. First, to examine the nature of the covalently attached sugars, the 45-kDa protein was obtained from cells metabolically labeled with D-[U-14C] glucose and subjected to compositional analysis, which revealed mannose as the only covalently bound sugar. Digestion of the protein with the endoproteinase subtilisin and analysis of products by liquid chromatography-electrospray-mass spectrometry on the basis of fragments demonstrating neutral losses of hexose (m/z 162) or pentose (m/z 132) revealed five glycopeptides, S7, S18, S22, S29, and S41 among a total of 50 peptides, all of which produced only m/z 162 fragmentation ion deletions. Fast atom bombardment-mass spectrometry, N-terminal amino acid sequencing, and alpha-mannosidase digestion demonstrated universal O glycosylation of Thr residues with a single alpha-D-Man, mannobiose, or mannotriose unit. Linkages within the mannobiose and mannotriose were all alpha 1-2, as proven by gas chromatography-mass spectrometry of oligosaccharides released by beta-elimination. Total sequences of many of the glycosylated and nonglycosylated peptides combined with published information on the deduced amino acid sequence of the entire 45-kDa protein demonstrated that the sites of glycosylation were located in Pro-rich domains near the N terminus and C terminus of the polypeptide backbone. Specifically, the Thr residues at positions 10 and 18 were substituted with alpha-D-Manp(1-->2)alpha-D-Manp, the Thr residue at position 27 was substituted with a single alpha-D-Manp, and Thr-277 was substituted with either alpha-D-Manp, alpha-D-Manp(1-->2)alpha-D-Manp, or alpha-D-Manp(1--> 2)alpha-D-Manp(1-->2)alpha-D-Manp. This report further corroborates the existence of true prokaryotic glycoproteins, defines the complete structure of a mycobacterial mannoprotein and the first complete structure of a mannosylated mycobacterial protein, and establishes the principles for the study of other mycobacterial glycoproteins.


Human satellite cells: identification on human muscle fibres.
Satellite cells, normally quiescent underneath the myofibre basal lamina, are skeletal muscle stem cells responsible for postnatal muscle growth, repair and regeneration. Since their scarcity and small size have limited study on transverse muscle sections, techniques to isolate individual myofibres, bearing their attendant satellite cells, were developed. Studies on mouse myofibres have generated much information on satellite cells, but the limited availability and small size of human muscle biopsies have hampered equivalent studies of satellite cells on human myofibres. Here, we identified satellite cells on fragments of human and mouse myofibres, using a method applicable to small muscle biopsies.


Cost-effective pharmacological prevention of acute coronary syndromes.
The growing size of trials on primary and secondary prevention of acute coronary syndromes characterised by very broad inclusion criteria may seem logical to 'trialists', who reason that the the broader the inclusion criteria, the easier it is to recruit large numbers of patients in a short period of time and the more widely applicable are the results of the study. However, large trials with very broad inclusion criteria raise two grounds for concern for physicians. The first is that the broader the inclusion criteria for enrollment in a trial in order to prove a statistically significant benefit, the greater the heterogeneity of the study population which is likely to include both susceptible and non-susceptible patients to the tested treatment. The second is that this method of assessment rapidly increases the number of treatments that produce a statistically-significant improvement in prognosis within the same broad group of patients. On the contrary, the identification of potential responders to a specific treatment can provide a personalised form of medical care suited to the needs of each individual patient with an optimal cost-benefit ratio. This approach, however, represents a major challenge as it can only be based on the identification of homogeneous subgroups of patients with common risk factors for the development of acute coronary syndromes or of their recurrence. This challenge can only be overcome by a strong commitment in funding studies on the multiple causes of acute coronary syndromes.


Remittances in the Republic of Georgia: correlates, economic impact, and social capital formation.
The economic impact of remittances on migrant-sending countries has been a subject of debate in the scholarly literature on migration. We consider the topic using a household-level approach. We use a new survey, "Georgia on the Move," to examine migrant-level, household-level, and contextual variables associated with the probability that a household in the Republic of Georgia receives remittances. We then apply propensity score matching to estimate how remittances affect particular types of household expenditures, savings, labor supply, health, and other measures of well-being. Separate analysis of the subsample of households with a migrant currently abroad distinguishes the effects of remittances from the effects of migration as such. In Georgia, remittances improve household economic well-being without, for the most part, producing the negative consequences often suggested in the literature. We find evidence for an important aspect that has not been widely discussed in prior studies: remittances foster the formation of social capital by increasing the amount of money that households give as gifts to other households.


Image-guided surgical microscope with mounted minitracker.
A new image-guided microscope using augmented reality overlays has been developed. Unlike other systems, the novelty of our design consists in mounting a precise mini and low-cost tracker directly on the microscope to track the motion of the surgical tools and the patient. Correctly scaled cut-views of the pre-operative computed tomography (CT) stack can be displayed on the overlay, orthogonal to the optical view or even including the direction of a clinical tool. Moreover, the system can manage three-dimensional models for tumours or bone structures and allows interaction with them using virtual tools, showing trajectories and distances. The mean error of the overlay was 0.7 mm. Clinical accuracy has shown results of 1.1-1.8 mm.


The molecular and pharmacological properties of muscarinic cholinergic receptors expressed by rat sweat glands are unaltered by denervation.
Previous studies have indicated that denervation of adult rodent sweat glands results in the loss of secretory responsiveness to muscarinic agonists. To elucidate the molecular basis of this loss, we have characterized the muscarinic cholinergic receptor present in adult rat sweat glands and examined the effects of cholinergic denervation on its properties and expression. When homogenates of gland-rich tissue from adult animals were assayed with [N-methyl-3H]-scopolamine, a high-affinity muscarinic antagonist, the concentration of muscarinic receptors was 301 fmol/mg protein and the affinity was 131 pM. Autoradiographic analysis demonstrated that ligand binding sites were detectable only on glands. In competition studies with well-characterized muscarinic agents, the receptor exhibited typical muscarinic pharmacology. Further investigation with the selective muscarinic antagonists 4-diphenylacetoxy-N-methylpiperidine methiodide, pirenzepine, and AF DX-116 revealed that the sweat gland receptor belongs to the M2 glandular pharmacological subtype. In situ hybridization histochemistry with receptor subtype-specific oligonucleotide probes indicated that rat sweat glands express the m3 molecular receptor subtype. Seven days after sciatic nerve transection, when denervated glands were compared to those on the contralateral unoperated side, there was no significant difference either in the concentration or affinity of muscarinic binding sites or in receptor density or distribution. Furthermore, the molecular subtype and the level of its expression were unchanged. Thus, it appears that muscarinic binding sites and m3 receptor mRNA are present in denervated sweat glands that are unresponsive to muscarinic stimulation. These results suggest that the regulation of responsiveness occurs at a point distal to the expression of muscarinic receptors.


Modeling regulatory mechanisms in IL-6 signal transduction in hepatocytes.
Cytokines like interleukin-6 (IL-6) play an important role in triggering the acute phase response of the body to injury or inflammation. Signaling by IL-6 involves two pathways: Janus-associated kinases (JAK) and signal transducers and activators of transcription (STAT 3) are activated in the first pathway while the second pathway involves the activation of mitogen-activated protein kinases (MAPK). While it is recognized that both pathways play a major role in IL-6 signal transduction, a majority of studies have focused on signaling through either one of the pathways. However, simultaneous signaling through both JAK/STAT and MAPK pathways is still poorly understood. In this work, a mathematical model has been developed that integrates signaling through both the JAK/STAT and the MAPK pathway. The presented model is used to analyze the effect of three molecules that are involved in the regulation of IL-6 signaling-SHP-2 (domain containing tyrosine phosphatase 2), SOCS3 (suppressor of cytokine signaling 3), and a STAT3 nuclear phosphatase (PP2)-on the dynamics of IL-6 signal transduction in hepatocytes. The obtained results suggest that interactions between SHP-2 and SOCS3 influence signaling through the JAK/STAT and the MAPK pathways. It is shown that SHP-2 and SOCS3 do not just regulate the pathway that they are known to be associated with, (SHP-2 with MAPK and SOCS3 with JAK/STAT), but also have a strong effect on the other pathway. Several simulations with SOCS3, SHP-2, and PP2 knockout cells, that is, where the signaling pathway is unable to produce these proteins, have been performed to characterize the effect of these regulatory proteins on IL-6 signal transduction in hepatocytes.


Controversies on Hodgkin's disease and anaplastic large cell lymphoma. Hematopathology Study Group of the Società Italiana di Anatomia Patologica.
Just one year ago the Italian Society of Pathology (S.I.A.P.) created a Study Group which included members of the most active Italian hematopathology teams. Prof. Pasquale Calapso was asked to chair the Group and Prof. Stefano Pileri to take care of secretarial duties. The aim of the Group is to spread hematopathologic knowledge among young pathologists and to promote activities that can contribute to updating Italian pathologists on topics of both speculative and diagnostic interest. The first Workshop of the S.I.A.P. Hematopathology Group was held at the Palazzo dei Congressi in Bologna, November 20, 1993. About 150 pathologists from all over Italy took part in the meeting, which consisted of two sections devoted to: a) discussion of the boundaries between Hodgkin's disease and non-Hodgkin's lymphomas, and b) a case seminar illustrating the impact of immunohistochemistry in the diagnosis of bone-marrow biopsy. The first section included 5 presentations and a Round Table chaired by Prof. Luciano Fiore-Donati. Below, the contributors to this section summarize the content of their presentations, which were aimed at answering specific questions the Organizers had put to them.


Computer modeling reveals that modifications of the histone tail charges define salt-dependent interaction of the nucleosome core particles.
Coarse-grained Langevin molecular dynamics computer simulations were conducted for systems that mimic solutions of nucleosome core particles (NCPs). The NCP was modeled as a negatively charged spherical particle representing the complex of DNA and the globular part of the histones combined with attached strings of connected charged beads modeling the histone tails. The size, charge, and distribution of the tails relative to the core were built to match real NCPs. Three models of NCPs were constructed to represent different extents of covalent modification on the histone tails: (nonmodified) recombinant (rNCP), acetylated (aNCP), and acetylated and phosphorylated (paNCP). The simulation cell contained 10 NCPs in a dielectric continuum with explicit mobile counterions and added salt. The NCP-NCP interaction is decisively dependent on the modification state of the histone tails and on salt conditions. Increasing the monovalent salt concentration (KCl) from salt-free to physiological concentration leads to NCP aggregation in solution for rNCP, whereas NCP associates are observed only occasionally in the system of aNCPs. In the presence of divalent salt (Mg(2+)), rNCPs form dense stable aggregates, whereas aNCPs form aggregates less frequently. Aggregates are formed via histone-tail bridging and accumulation of counterions in the regions of NCP-NCP contacts. The paNCPs do not show NCP-NCP interaction upon addition of KCl or in the presence of Mg(2+). Simulations for systems with a gradual substitution of K(+) for Mg(2+), to mimic the Mg(2+) titration of an NCP solution, were performed. The rNCP system showed stronger aggregation that occurred at lower concentrations of added Mg(2+), compared to the aNCP system. Additional molecular dynamics simulations performed with a single NCP in the simulation cell showed that detachment of the tails from the NCP core was modest under a wide range of salt concentrations. This implies that salt-induced tail dissociation of the histone tails from the globular NCP is not in itself a major factor in NCP-NCP aggregation. The approximation of coarse-graining, with respect to the description of the NCP as a sphere with uniform charge distribution, was tested in control simulations. A more detailed description of the NCP did not change the main features of the results. Overall, the results of this work are in agreement with experimental data reported for NCP solutions and for chromatin arrays.


Transfer of carbon atoms among circulating glucose, alanine, and lactate in pancreatectomized dogs.
The rates of transfer of carbon atoms (mg C . kg body wt-1 . min-1) among plasma glucose, alanine, and lactate have been calculated in pancreatectomized dogs from the tracer concentration versus time curves in the plasma after an intravenous injection of either [2,3-3H]- and [U-14C]alanine or [3-3H]- and [U-14C]glucose. The calculations were based on an integrated kinetic model derived earlier from experimental data. In comparison to normal dogs, in insulin-deprived pancreatectomized dogs, the rate of turnover of glucose (mg C . kg-1 . min-1) is increased about twofold, but the turnover rates of lactate and alanine are not changed significantly. About twice as much carbon is transferred from lactate to glucose, whereas the transfer of carbon from alanine is increased by 47%. Carbon transfer to glucose from unidentified sources is also doubled. In conclusion, in the pancreatectomized dog, gluconeogenesis is increased not by an increased production of alanine and lactate but by an increased diversion of their carbon atoms to glucose at the expense of other pathways.


The Andro Project: physiological and hormonal influences of androstenedione supplementation in men 35 to 65 years old participating in a high-intensity resistance training program.
Since the passage of The Dietary Supplement Health and Education Act in 1994, there has been a flood of new "dietary" supplements promoting anti-aging benefits such as the enhancement of growth hormone or testosterone levels. Androstenediol and androstenedione are such products. This study's purpose was to elucidate the physiological and hormonal effects of 200 mg/d of oral androstenediol and androstenedione supplementation in men aged 35 to 65 years while participating in a 12-week high-intensity resistance training program. Fifty men not consuming any androgenic-enhancing substances and with normal total testosterone levels, prostate-specific antigen, hemoglobin, and hematocrit, and with no sign of cardiovascular or metabolic diseases participated. Subjects were randomly assigned to a placebo, androstenediol (diol), or androstenedione (dione) group using a double-blind study design. Main outcomes included serum sex hormone profile, body composition assessment, muscular strength, and blood lipid profiles. During the 12 weeks of androstenedione or androstenediol use, a significant increase in the aromatization by-products estrone and estradiol was observed in both groups (P =.03). In the dione group, total testosterone levels significantly increased 16% after 1 month of use, but by the end of 12 weeks, they returned to pretreatment levels. This return to baseline levels resulted from increases in aromatization and down-regulation in endogenous testosterone synthesis based on the fact that luteinizing hormone was attenuated 18% to 33% during the treatment period. Neither androstenediol nor androstenedione enhanced the adaptations to resistance training compared with placebo for body composition or muscular strength. However, both androstenediol and androstenedione supplementation adversely affected high-density lipoprotein cholesterol (HDL-C) levels, coronary heart disease risk (representing a 6.5% increase), and each group's respective (low-density lipoprotein cholesterol [LDL-C]/HDL-C)/(apolipoprotein A/apolipoprotein B) lipid ratio (diol: +5.2%; dione: +10.5%; P =.05). In contrast, the placebo group's HDL-C levels increased 5.1%, with a 12.3% decline in the (LDL-C/HDL-C)/(apolipoprotein A/apolipoprotein B) lipid ratio. These negative and positive lipid effects occurred despite no significant alterations in body composition or dietary intakes in the supplemental groups or placebo group, respectively. Testosterone precursors do not enhance adaptations to resistance training when consumed in dosages recommended by manufacturers. Testosterone precursor supplementation does result in significant increases in estrogen-related compounds, dehydroepiandrosterone sulfate concentrations, down-regulation in testosterone synthesis, and unfavorable alterations in blood lipid and coronary heart disease risk profiles of men aged 35 to 65 years.


Ventricular Catheter Systems with Subcutaneous Reservoirs (Ommaya Reservoirs) in Pediatric Patients with Brain Tumors: Infections and Other Complications.
This study aims to describe complications related to ventricular catheter systems with subcutaneous reservoirs (VCSR) (such as Ommaya reservoirs) in pediatric patients with brain tumors. Retrospective analysis of consecutive patients with a total of 31 VCSR treated at the Children's University Hospital of Zurich, Switzerland. A total of 20 patients with a median age of 3.3 years at VCSR implantation received 31 VCSR. Overall, 19 complications in 11 patients were recorded: 7 patients had a VCSR-related infection with coagulase-negative staphylococci, 4 of these probably as a surgical complication and 3 probably related to VCSR use. Systemic perioperative prophylaxis was administered in 22 cases, and intraventricular vancomycin and gentamicin were given in 8 cases (none of which subsequently developed an infection). Other complications included wound dehiscence, catheter malplacement, and leakage of cerebrospinal fluid. Overall, 17 VCSR were explanted due to complications. Infections were the most frequent VCSR-related complication. In our own institution, the high rate of complications led to the definition of a bundle of measures as a standard operating procedure for VCSR placement and use. Prospective studies in larger patient collectives are warranted to better identify risk factors and evaluate preventive measures such as the administration of perioperative antibiotics and the use of antimicrobial coating of catheters.


Soybean isoflavone extract suppresses early but not later promotion of hepatocarcinogenesis by phenobarbital in female rat liver.
The antioxidant and anticarcinogenic activities of soybean isoflavone extracts were investigated in female F344/rats. Diethylnitrosamine (DEN, 15 mg/kg body wt) as a cancer initiator was injected intraperitoneally into 120 female F344/N rats at 10 days of age, and at weaning, phenobarbital (PB, 500 mg/kg diet) was fed to one-half of the rats. Soybean isoflavones were extracted in acetone-0.1 N HCl and analyzed by high-performance liquid chromatography, and two levels of soybean isoflavones (920 and 1,840 mumol/kg diet) were fed during PB treatment for 3 and 11 months. Control rats were fed diets without PB and with or without isoflavones. The effect of soybean isoflavone extract on hepatic glutathione peroxidase was measured, and development of gamma-glutamyltransferase (GGT)-positive (GGT+) and placental glutathione transferase (PGST)-positive (PGST+) altered hepatic foci (AHF) was analyzed by computerized stereology. Soybean isoflavone extract providing 920 or 1,840 mumol/kg diet normalized total heptic glutathione peroxidase activity, which was suppressed about 17% by PB (p < 0.05), and both doses of isoflavone extract suppressed PB promotion of hepatocarcinogenesis, decreasing the volume occupied by GGT+ and PGST+ AHF (p < 0.05) after three months. After 11 months of PB promotion, isoflavone extract at 920 mumol/kg diet decreased PGST+ AHF compared with the PB-fed group, but neither dose of isoflavone extract suppressed development of GGT+ AHF compared with the group fed PB alone. Furthermore the control group fed isoflavone extract at 1,840 mumol/kg diet showed greater development of GGT+ and PGST+ AHF than the group fed the basal diet alone. Therefore soybean isoflavones may be anticarcinogenic, but their margin of safety is relatively narrow, with a cancer-promoting dose of 1,840 mumol/kg in female F344/N rats initiated with DEN.


Accumulation of coronary artery disease risk factors over three years: data from an international inception cohort.
To examine the accumulation of risk factors over 3 years in a multicenter, international inception cohort of patients with systemic lupus erythematosus (SLE). The Systemic Lupus International Collaborating Clinics registry for atherosclerosis comprises 27 centers from 11 countries. An inception cohort of 935 patients with SLE was assembled, according to a standardized protocol, from 2000 to 2006 to study risk factors for atherosclerosis. Both classic and other coronary artery disease (CAD) risk factors were collected at entry and through 3 years of followup. Therapy was documented over the 3 years. The Framingham 10-year risk factor profile was calculated for each patient at year 1 and year 3. A total of 278 patients from the inception cohort were followed for 3 years and constituted the population for this study. At enrollment a substantial number of patients already demonstrated several risk factors for CAD, both classic and other. All risk factors increased from enrollment over the 3 years of followup. Treatment of hypertension and hypercholesterolemia also increased over 3 years, but less so for hypercholesterolemia. The Framingham 10-year CAD risk profile was higher in men than in women both at entry and at 3 years, and remained unchanged over the 3 years. Corticosteroid use increased only slightly over 3 years, but use of antimalarials and immunosuppressive agents increased to a greater extent. Patients with SLE should be monitored for CAD risk factors from the time of diagnosis and appropriate treatment should be instituted early.


Dynamic primitives of brain network interaction.
What dynamic processes underly functional brain networks? Functional connectivity (FC) and functional connectivity dynamics (FCD) are used to represent the patterns and dynamics of functional brain networks. FC(D) is related to the synchrony of brain activity: when brain areas oscillate in a coordinated manner this yields a high correlation between their signal time series. To explain the processes underlying FC(D) we review how synchronized oscillations emerge from coupled neural populations in brain network models (BNMs). From detailed spiking networks to more abstract population models, there is strong support for the idea that the brain operates near critical instabilities that give rise to multistable or metastable dynamics that in turn lead to the intermittently synchronized slow oscillations underlying FC(D). We explore further consequences from these fundamental mechanisms and how they fit with reality. We conclude by highlighting the need for integrative brain models that connect separate mechanisms across levels of description and spatiotemporal scales and link them with cognitive function.


Using registries to identify adverse events in rheumatic diseases.
The proven effectiveness of biologics and other immunomodulatory products in inflammatory rheumatic diseases has resulted in their widespread use as well as reports of potential short- and long-term complications such as infection and malignancy. These complications are especially worrisome in children who often have serial exposures to multiple immunomodulatory products. Post-marketing surveillance of immunomodulatory products in juvenile idiopathic arthritis (JIA) and pediatric systemic lupus erythematosus is currently based on product-specific registries and passive surveillance, which may not accurately reflect the safety risks for children owing to low numbers, poor long-term retention, and inadequate comparators. In collaboration with the US Food and Drug Administration (FDA), patient and family advocacy groups, biopharmaceutical industry representatives and other stakeholders, the Childhood Arthritis and Rheumatology Research Alliance (CARRA) and the Duke Clinical Research Institute (DCRI) have developed a novel pharmacosurveillance model (CARRA Consolidated Safety Registry [CoRe]) based on a multicenter longitudinal pediatric rheumatic diseases registry with over 8000 participants. The existing CARRA infrastructure provides access to much larger numbers of subjects than is feasible in single-product registries. Enrollment regardless of medication exposure allows more accurate detection and evaluation of safety signals. Flexibility built into the model allows the addition of specific data elements and safety outcomes, and designation of appropriate disease comparator groups relevant to each product, fulfilling post-marketing requirements and commitments. The proposed model can be applied to other pediatric and adult diseases, potentially transforming the paradigm of pharmacosurveillance in response to the growing public mandate for rigorous post-marketing safety monitoring.


5-Alkyl-2-(alkylthio)-6-(2,6-dihalophenylmethyl)-3, 4-dihydropyrimidin-4(3H)-ones: novel potent and selective dihydro-alkoxy-benzyl-oxopyrimidine derivatives.
Molecular modeling analysis of compounds belonging to the recently published series of dihydro-alkoxy-benzyl-oxopyrimidines (DABOs), such as S-DABOs and DATNOs, gave support to the design of new 2, 6-disubstituted benzyl-DABO derivatives as highly potent and specific inhibitors of the HIV-1 reverse transcriptase (RT). To follow up on the novel DABO derivatives, we decided to investigate the effect of electron-withdrawing substituents in the benzyl unit of the S-DABO skeleton versus their anti-HIV-1 activity. Such chemical modifications impacted the inhibitory activity, especially when two halogen units were introduced at positions 2 and 6 in the phenyl portion of the benzyl group bound to C-6 of the pyrimidine ring. Various 5-alkyl-2-(alkyl(or cycloalkyl)thio)-6-(2, 6-dichloro(or 2,6-difluoro)phenylmethyl)-3, 4-dihydropyrimidin-4(3H)-ones were then synthesized and tested as anti-HIV-1 agents in both cell-based and enzyme (recombinant reverse transcriptase, rRT) assays. Among the various mono- and disubstituted phenyl derivatives, the most potent were those containing a 6-(2,6-difluorophenylmethyl) substituent (F-DABOs), which showed EC50's ranging between 40 and 90 nM and selectivity indexes up to >/=5000. An excellent correlation was found between EC50 and IC50 values which confirmed that these compounds act as inhibitors of the HIV-1 RT. The structure-activity relationships of the newly synthesized pyrimidinones are presented herein.


Evidence Suggesting That Discontinuous Dosing of ALK Kinase Inhibitors May Prolong Control of ALK+ Tumors.
The anaplastic lymphoma kinase (ALK) is chromosomally rearranged in a subset of certain cancers, including 2% to 7% of non-small cell lung cancers (NSCLC) and ∼70% of anaplastic large cell lymphomas (ALCL). The ALK kinase inhibitors crizotinib and ceritinib are approved for relapsed ALK(+) NSCLC, but acquired resistance to these drugs limits median progression-free survival on average to ∼10 months. Kinase domain mutations are detectable in 25% to 37% of resistant NSCLC samples, with activation of bypass signaling pathways detected frequently with or without concurrent ALK mutations. Here we report that, in contrast to NSCLC cells, drug-resistant ALCL cells show no evidence of bypassing ALK by activating alternate signaling pathways. Instead, drug resistance selected in this setting reflects upregulation of ALK itself. Notably, in the absence of crizotinib or ceritinib, we found that increased ALK signaling rapidly arrested or killed cells, allowing a prolonged control of drug-resistant tumors in vivo with the administration of discontinuous rather than continuous regimens of drug dosing. Furthermore, even when drug resistance mutations were detected in the kinase domain, overexpression of the mutant ALK was toxic to tumor cells. We confirmed these findings derived from human ALCL cells in murine pro-B cells that were transformed to cytokine independence by ectopic expression of an activated NPM-ALK fusion oncoprotein. In summary, our results show how ALK activation functions as a double-edged sword for tumor cell viability, with potential therapeutic implications.


The Video Head Impulse Test.
In 1988, we introduced impulsive testing of semicircular canal (SCC) function measured with scleral search coils and showed that it could accurately and reliably detect impaired function even of a single lateral canal. Later we showed that it was also possible to test individual vertical canal function in peripheral and also in central vestibular disorders and proposed a physiological mechanism for why this might be so. For the next 20 years, between 1988 and 2008, impulsive testing of individual SCC function could only be accurately done by a few aficionados with the time and money to support scleral search-coil systems-an expensive, complicated and cumbersome, semi-invasive technique that never made the transition from the research lab to the dizzy clinic. Then, in 2009 and 2013, we introduced a video method of testing function of each of the six canals individually. Since 2009, the method has been taken up by most dizzy clinics around the world, with now close to 100 refereed articles in PubMed. In many dizzy clinics around the world, video Head Impulse Testing has supplanted caloric testing as the initial and in some cases the final test of choice in patients with suspected vestibular disorders. Here, we consider seven current, interesting, and controversial aspects of video Head Impulse Testing: (1) introduction to the test; (2) the progress from the head impulse protocol (HIMPs) to the new variant-suppression head impulse protocol (SHIMPs); (3) the physiological basis for head impulse testing; (4) practical aspects and potential pitfalls of video head impulse testing; (5) problems of vestibulo-ocular reflex gain calculations; (6) head impulse testing in central vestibular disorders; and (7) to stay right up-to-date-new clinical disease patterns emerging from video head impulse testing. With thanks and appreciation we dedicate this article to our friend, colleague, and mentor, Dr Bernard Cohen of Mount Sinai Medical School, New York, who since his first article 55 years ago on compensatory eye movements induced by vertical SCC stimulation has become one of the giants of the vestibular world.


Cytoplasmic CUG RNA foci are insufficient to elicit key DM1 features.
The genetic basis of myotonic dystrophy type I (DM1) is the expansion of a CTG tract located in the 3' untranslated region of DMPK. Expression of mutant RNAs encoding expanded CUG repeats plays a central role in the development of cardiac disease in DM1. Expanded CUG tracts form both nuclear and cytoplasmic aggregates, yet the relative significance of such aggregates in eliciting DM1 pathology is unclear. To test the pathophysiology of CUG repeat encoding RNAs, we developed and analyzed mice with cardiac-specific expression of a beta-galactosidase cassette in which a (CTG)(400) repeat tract was positioned 3' of the termination codon and 5' of the bovine growth hormone polyadenylation signal. In these animals CUG aggregates form exclusively in the cytoplasm of cardiac cells. A key pathological consequence of expanded CUG repeat RNA expression in DM1 is aberrant RNA splicing. Abnormal splicing results from the functional inactivation of MBNL1, which is hypothesized to occur due to MBNL1 sequestration in CUG foci or from elevated levels of CUG-BP1. We therefore tested the ability of cytoplasmic CUG foci to elicit these changes. Aggregation of CUG RNAs within the cytoplasm results both in Mbnl1 sequestration and in approximately a two fold increase in both nuclear and cytoplasmic Cug-bp1 levels. Significantly, despite these changes RNA splice defects were not observed and functional analysis revealed only subtle cardiac dysfunction, characterized by conduction defects that primarily manifest under anesthesia. Using a human myoblast culture system we show that this transgene, when expressed at similar levels to a second transgene, which encodes expanded CTG tracts and facilitates both nuclear focus formation and aberrant splicing, does not elicit aberrant splicing. Thus the lack of toxicity of cytoplasmic CUG foci does not appear to be a consequence of low expression levels. Our results therefore demonstrate that the cellular location of CUG RNA aggregates is an important variable that influences toxicity and support the hypothesis that small molecules that increase the rate of transport of the mutant DMPK RNA from the nucleus into the cytoplasm may significantly improve DM1 pathology.


Eicosapentaenoic acid improves glycemic control in elderly bedridden patients with type 2 diabetes.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are ω3-polyunsaturated fatty acids mainly contained in the blue-backed fish oil, and are effective in decreasing the lipids disorder and the cardiovascular incidence among diabetic patients. Moreover, it has been suggested that EPA and DHA may improve the insulin resistance and glucose metabolism. However, the clinical effects of EPA and DHA on glucose metabolism remain unclear. We aimed to clarify the effects of EPA/DHA treatment on glycemic control in type 2 diabetes mellitus. This study was a multicenter prospective randomized controlled trial involving 30 elderly type 2 diabetic patients on a liquid diet. Their exercises were almost zero and the content of their meals was strictly managed and understood well. Therefore, the difference by the individual's life was a minimum. The subjects were divided into two groups: those receiving EPA/DHA-rich liquid diet [EPA/DHA (+)] or liquid diet lacking EPA/DHA [EPA/DHA (-)]. Changes in factors related to glucose and lipid metabolism were assessed after the three-month study. Serum concentrations of EPA rose in EPA/DHA (+), although the levels of DHA and fasting C-peptide remained unchanged in EPA/DHA (+). In addition, there was a significant decline in the fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), fasting remnant-like particles and apolipoprotein (apo) B in EPA/DHA (+), compared with the values in EPA/DHA (-). EPA/DHA-rich diet might improve glucose metabolism in elderly type 2 diabetic patients on a liquid diet. This phenomenon may be due to the improved insulin resistance mediated by the rise in serum EPA concentrations.


International flow of Zambian nurses.
This commentary paper highlights changing patterns of outward migration of Zambian nurses. The aim is to discuss these pattern changes in the light of policy developments in Zambia and in receiving countries. Prior to 2000, South Africa was the most important destination for Zambian registered nurses. In 2000, new destination countries, such as the United Kingdom, became available, resulting in a substantial increase in migration from Zambia. This is attributable to the policy of active recruitment by the United Kingdom's National Health Service and Zambia's policy of offering Voluntary Separation Packages: early retirement lump-sum payments promoted by the government, which nurses used towards migration costs. The dramatic decline in migration to the United Kingdom since 2004 is likely to be due to increased difficulties in obtaining United Kingdom registration and work permits. Despite smaller numbers, enrolled nurses are also leaving Zambia for other destination countries, a significant new development. This paper stresses the need for nurse managers and policy-makers to pay more attention to these wider nurse migration trends in Zambia, and argues that the focus of any migration strategy should be on how to retain a motivated workforce through improving working conditions and policy initiatives to encourage nurses to stay within the public sector.


Glial tumor grading and outcome prediction using dynamic spin-echo MR susceptibility mapping compared with conventional contrast-enhanced MR: confounding effect of elevated rCBV of oligodendrogliomas [corrected].
The MR imaging characteristics of oligodendrogliomas and astrocytomas on spin-echo (SE), echo-planar relative cerebral blood volume (rCBV) maps, to our knowledge, have not previously been emphasized. We compared the specificity of SE rCBV mapping with that of conventional, contrast material-enhanced MR imaging in differentiating high- from low-grade glial tumors and in predicting survival of patients with these lesions. Thirty consecutive adult patients with suspected gliomas underwent conventional and rCBV MR imaging. Representative maximal rCBV regions of interest were chosen from each lesion. Resultant values were normalized to those of corresponding, contralateral, uninvolved regions. These normalized CBV (nCBV) values were correlated with degree of contrast enhancement, histopathologic tumor grade, and survival. Twenty-two patients had astroctyomas and eight had oligodendrogliomas. With an nCBV cutoff ratio of 1.5, 13 of 13 high-grade astrocytomas were correctly categorized, three of which did not enhance. Seven of nine low-grade astrocytomas were correctly classified by their nCBV values, including one enhancing lesion. Of eight oligodendrogliomas, four of four high-grade and two of four low-grade tumors had elevated nCBV values; two low-grade oligodendrogliomas enhanced, one with nCBV greater than 1.5 and one with nCBV less than 1.5. In 19 patients with astrocytoma for whom survival data were available, correlation with survival was better for nCBV (mean survival 91 +/- 14 months for nCBV < 1.5 versus 24 +/- 27 months for nCBV > 1.5, P <.0001) than for enhancement (mean survival 61 +/- 35 months without enhancement versus 22 +/- 29 months with enhancement, P =.03). Elevated SE rCBV was a sensitive, but not specific, marker for high-grade histopathology: all high-grade tumors had nCBV foci values greater than 1.5. No tumor with nCBV region of interest less than 1.5 was high grade (100% predictive value for excluding high grade). Degree of nCBV elevation was a stronger predictor of both tumor grade and survival than was degree of enhancement. A significant proportion of low-grade glial neoplasms, most notably oligodendrogliomas, may display high rCBV foci not reflective of high-grade histopathology.


Replication properties of dUTPase-deficient mutants of caprine and ovine lentiviruses.
The virion-associated dUTPase activities of caprine arthritis-encephalitis virus (CAEV) and visna virus were determined by using an assay which measure the actual ability of the dUTPase to prevent the dUTP misincorporations into cDNA during reverse transcription. We showed that the CAEV molecular clone from the Cork isolate was dUTPase defective as a result of a single amino acid substitution. Using this point mutant and deletion mutants of CAEV as well as a deletion mutant of visna virus, we demonstrated that dUTPase-deficient viruses replicate similarly to wild-type viruses in dividing cells but show delayed replication in nondividing primary macrophages.


The evolutionary history of polycotylid plesiosaurians.
Polycotylidae is a clade of plesiosaurians that appeared during the Early Cretaceous and became speciose and abundant early in the Late Cretaceous. However, this radiation is poorly understood. Thililua longicollis from the Middle Turonian of Morocco is an enigmatic taxon possessing an atypically long neck and, as originally reported, a series of unusual cranial features that cause unstable phylogenetic relationships for polycotylids. We reinterpret the holotype specimen of Thililua longicollis and clarify its cranial anatomy. Thililua longicollis possesses an extensive, foramina-bearing jugal, a premaxilla-parietal contact and carinated teeth. Phylogenetic analyses of a new cladistic dataset based on first-hand observation of most polycotylids recover Thililua and Mauriciosaurus as successive lineages at the base of the earliest Late Cretaceous polycotyline radiation. A new dataset summarizing the Bauplan of polycotylids reveals that their radiation produced an early burst of disparity during the Cenomanian-Turonian interval, with marked plasticity in relative neck length, but this did not arise as an ecological release following the extinction of ichthyosaurs and pliosaurids. This disparity vanished during and after the Turonian, which is consistent with a model of 'early experimentation/late constraint'. Two polycotylid clades, Occultonectia clade nov. and Polycotylinae, survived up to the Maastrichtian, but with low diversity.


Identifying a human rights-based approach to obesity for States and civil society.
Obesity and its comorbidities pose daunting challenges to global health and development in the 21st century. This paper reviews some commonalities between obesity and another global health challenge, the pandemic of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). International human rights law was an important catalyst for civil society movements that helped to overcome inertia and generate political will for State action in response to HIV and AIDS. Drawing on the HIV experience, the authors propose a conceptual model for a human rights-based response to obesity founded on the twin pillars of State obligations and civil society engagement. Framing States' obligations to address the global obesity pandemic as a matter of international law, informed by the examples of the United Nations "International Guidelines on HIV/AIDS and Human Rights" and the General Comments of the United Nations human rights treaty bodies on HIV and AIDS, provides a normative framework to guide State actions and opportunities to engage the extensive accountability mechanisms of the United Nations international human rights system. In addition, it provides civil society organizations with the language and tools to demand State action on obesity. The authors call for similar authoritative guidance for States on the application of international human rights law to obesity.


The quantification of hemodynamic parameters downstream of a Gianturco Zenith stent wire using newtonian and non-newtonian analog fluids in a pulsatile flow environment.
Although deployed in the vasculature to expand vessel diameter and improve blood flow, protruding stent struts can create complex flow environments associated with flow separation and oscillating shear gradients. Given the association between magnitude and direction of wall shear stress (WSS) and endothelial phenotype expression, accurate representation of stent-induced flow patterns is critical if we are to predict sites susceptible to intimal hyperplasia. Despite the number of stents approved for clinical use, quantification on the alteration of hemodynamic flow parameters associated with the Gianturco Z-stent is limited in the literature. In using experimental and computational models to quantify strut-induced flow, the majority of past work has assumed blood or representative analogs to behave as Newtonian fluids. However, recent studies have challenged the validity of this assumption. We present here the experimental quantification of flow through a Gianturco Z-stent wire in representative Newtonian and non-Newtonian blood analog environments using particle image velocimetry (PIV). Fluid analogs were circulated through a closed flow loop at physiologically appropriate flow rates whereupon PIV snapshots were acquired downstream of the wire housed in an acrylic tube with a diameter characteristic of the carotid artery. Hemodynamic parameters including WSS, oscillatory shear index (OSI), and Reynolds shear stresses (RSS) were measured. Our findings show that the introduction of the stent wire altered downstream hemodynamic parameters through a reduction in WSS and increases in OSI and RSS from nonstented flow. The Newtonian analog solution of glycerol and water underestimated WSS while increasing the spatial coverage of flow reversal and oscillatory shear compared to a non-Newtonian fluid of glycerol, water, and xanthan gum. Peak RSS were increased with the Newtonian fluid, although peak values were similar upon a doubling of flow rate. The introduction of the stent wire promoted the development of flow patterns that are susceptible to intimal hyperplasia using both Newtonian and non-Newtonian analogs, although the magnitude of sites affected downstream was appreciably related to the rheological behavior of the analog. While the assumption of linear viscous behavior is often appropriate in quantifying flow in the largest arteries of the vasculature, the results presented here suggest this assumption overestimates sites susceptible to hyperplasia and restenosis in flow characterized by low and oscillatory shear.


Selectivity filter instability dominates the low intrinsic activity of the TWIK-1 K2P K+ channel.
Two-pore domain K+ (K2P) channels have many important physiological functions. However, the functional properties of the TWIK-1 (K2P1.1/KCNK1) K2P channel remain poorly characterized because heterologous expression of this ion channel yields only very low levels of functional activity. Several underlying reasons have been proposed, including TWIK-1 retention in intracellular organelles, inhibition by posttranslational sumoylation, a hydrophobic barrier within the pore, and a low open probability of the selectivity filter (SF) gate. By evaluating these potential mechanisms, we found that the latter dominates the low intrinsic functional activity of TWIK-1. Investigating this further, we observed that the low activity of the SF gate appears to arise from the inefficiency of K+ in stabilizing an active (i.e. conductive) SF conformation. In contrast, other permeant ion species, such as Rb+, NH4+, and Cs+, strongly promoted a pH-dependent activated conformation. Furthermore, many K2P channels are activated by membrane depolarization via an SF-mediated gating mechanism, but we found here that only very strong nonphysiological depolarization produces voltage-dependent activation of heterologously expressed TWIK-1. Remarkably, we also observed that TWIK-1 Rb+ currents are potently inhibited by intracellular K+ (IC50 = 2.8 mm). We conclude that TWIK-1 displays unique SF gating properties among the family of K2P channels. In particular, the apparent instability of the conductive conformation of the TWIK-1 SF in the presence of K+ appears to dominate the low levels of intrinsic functional activity observed when the channel is expressed at the cell surface.


The acute phase response in children with mild and severe malaria in Papua New Guinea.
The production of acute phase proteins during infection is an important part of innate immunity and limits inflammation. However, little is known of the acute phase response in malaria. We measured acute phase proteins in plasma in children attending clinics and admitted to hospital with acute malaria in Papua New Guinea. Plasma ferritin concentration increased progressively with disease severity with markedly elevated levels in the most severely ill children. Plasma ferritin was >500 ng/ml in 7/99 (7.1%) outpatients with uncomplicated malaria, 22/100 (22.0%) hospital non-severe cases, 64/175 (36.6%) severe malaria cases who survived and 7/9 (77.8%) severe malaria deaths (P<0.001). The greatest concentration of ferritin (3561 ng/ml) was observed in a child who died. By contrast, C-reactive protein concentration was markedly increased in 153 children with uncomplicated malaria [median 203 (interquartile range 51-365) microg/ml] but, surprisingly, was only moderately increased in 135 children with one or more severe manifestations of malaria [47 (17-97) microg/ml; P<0.001] and in 6 children who died [41 (22-280) microg/ml]. Excessive free-radical damage resulting from a combination of iron-induced oxidant stress and reduced levels of C-reactive protein may be an important pathological mechanism in severe malaria and amenable to therapeutic intervention.


Clonal approaches to immune regulation by lymphocytes.
Analysis of immune regulation has been greatly facilitated by the development of clones of antigen reactive T cells. We have been analysing the regulation of these clones both by antigen, and by other cells, and review here the salient features of regulation of helper clones. Antigen at high concentrations may induce tolerance in a helper clone, in the absence of other T cells or accessory cells. This process was markedly antigen dose and time dependent, specific, and lasted at least 7 days. A key features was that response to TCGF was not altered. These experiments indicate that suppressor cells need not be involved in all forms of tolerance, and that antigen can interact directly with T cells. Regulation by an autologous anticlone raised by in vitro immunization of PBL with an irradiated clone is discussed. Its specificity for the immunizing clone suggests that it may recognize receptors, and suppressor clones of this type may be a possible strategy for regulating unwanted clones of lymphoid cells in autoimmunity or leukaemias. The implications of these findings for cancer in general are discussed.


Modular programming for tuberculosis control, the "AuTuMN" platform.
Tuberculosis (TB) is now the world's leading infectious killer and major programmatic advances will be needed if we are to meet the ambitious new End TB Targets. Although mathematical models are powerful tools for TB control, such models must be flexible enough to capture the complexity and heterogeneity of the global TB epidemic. This includes simulating a disease that affects age groups and other risk groups differently, has varying levels of infectiousness depending upon the organ involved and varying outcomes from treatment depending on the drug resistance pattern of the infecting strain. We adopted sound basic principles of software engineering to develop a modular software platform for simulation of TB control interventions ("AuTuMN"). These included object-oriented programming, logical linkage between modules and consistency of code syntax and variable naming. The underlying transmission dynamic model incorporates optional stratification by age, risk group, strain and organ involvement, while our approach to simulating time-variant programmatic parameters better captures the historical progression of the epidemic. An economic model is overlaid upon this epidemiological model which facilitates comparison between new and existing technologies. A "Model runner" module allows for predictions of future disease burden trajectories under alternative scenario situations, as well as uncertainty, automatic calibration, cost-effectiveness and optimisation. The model has now been used to guide TB control strategies across a range of settings and countries, with our modular approach enabling repeated application of the tool without the need for extensive modification for each application. The modular construction of the platform minimises errors, enhances readability and collaboration between multiple programmers and enables rapid adaptation to answer questions in a broad range of contexts without the need for extensive re-programming. Such features are particularly important in simulating an epidemic as complex and diverse as TB.


Cyclin D1 Promotes Androgen-Dependent DNA Damage Repair in Prostate Cancer Cells.
Therapy resistance and poor outcome in prostate cancer is associated with increased expression of cyclin D1. Androgens promote DNA double-strand break repair to reduce DNA damage, and cyclin D1 was also shown to enhance DNA damage repair (DDR). In this study, we investigated the significance of cyclin D1 in androgen-induced DDR using established prostate cancer cells and prostate tissues from cyclin D1 knockout mice. We demonstrate that endogenous cyclin D1 further diminished the dihydrotestosterone (DHT)-dependent reduction of γH2AX foci in vitro. We also show that cyclin D1 was required for the androgen-dependent DNA damage response both in vitro and in vivo. Furthermore, cyclin D1 was required for androgen-enhanced DDR and radioresistance of prostate cancer cells. Moreover, microarray analysis of primary prostate epithelial cells from cyclin D1-deficient and wild-type mice demonstrated that most of the DHT-dependent gene expression changes are also cyclin D1 dependent. Collectively, our findings suggest that the hormone-mediated recruitment of cyclin D1 to sites of DDR may facilitate the resistance of prostate cancer cells to DNA damage therapies and highlight the need to explore other therapeutic approaches in prostate cancer to prevent or overcome drug resistance.


[Microphthalmos and its pathogenic classification].
Congenital microphthalmos is a common malformation encountered clinically. Microphthalmos in adults is here defined as eyes whose axial length is below 20.4 mm in males and 20.1 mm in females; in under 14-year-old children, it is eyes at least 3 square root of 2/3 below the mean for age-similar controls. Experimental animals with hereditary microphthalmos have been widely investigated, and many environmental factors given to pregnant animals frequently induce microphthalmos. In both clinical and experimental microphthalmos, there are conspicuous variations in size, and various kinds of ocular and systemic complications. Recently, fetal alcohol syndrome produced by alcohol intake during pregnancy has been reported. In this syndrome, microphthalmos is one of the important symptoms. Experimentally, microphthalmos also developed at a high incidence among mouse fetuses whose mothers were given ethanol during pregnancy. The present investigator established a preliminary etiological classification of microphthalmos in 1984. In this paper summing up newly obtained results, the relationship to neural crest cells and histochemical changes of glycosaminoglycan molecular species, the author presents a final pathogenic classification of microphthalmos, which consists of developmental disturbance of the optic vesicle, malformation of the optic cup, mesenchymal dysgenesis of the anterior ocular segment, maldevelopment of the lens, maldevelopment of the vitreous, faulty closure of the embryonic fissure and developmental disturbance of the wall of eyeball.


Pathogenesis of Pichinde virus infection in strain 13 guinea pigs: an immunocytochemical, virologic, and clinical chemistry study.
Pichinde virus has been adapted to produce lethal infection of Strain 13 guinea pigs. Viral replication and presence of viral antigen in frozen tissues stained by immunofluorescence has been previously described. Further investigation into the pathogenesis of this disease has been hampered by the lack of a light microscopic method for correlating histologic lesions and the presence of Pichinde viral antigens. For this purpose, we developed a sensitive immunocytochemical technique for staining Pichinde viral antigens in formalin-fixed, paraffin-embedded tissue. Enhancement of the immunocytochemical staining with nickel chloride markedly improved detection of viral antigens. We examined frozen and formalin-fixed tissues from Strain 13 guinea pigs for viral antigens by light microscopy and immunocytochemistry at various intervals after infection with Pichinde virus. Progressive involvement of different tissues correlated with organ injury measured by serum biochemical abnormalities. Pichinde viral antigen was first detected in splenic macrophages five days after infection and their subsequent destruction facilitated persistent viremia. The inability to clear virus led to multiple organ infection and vascular involvement. Ensuing infections involved particularly the liver, spleen, adrenal glands, lungs, and intestines. Gastroenteritis developed, with extensive involvement of the muscularis mucosa throughout the gastrointestinal tract. Water and food intake decreased rapidly after day 8, leading to marked weight loss. Fatty changes of the liver suggested metabolic derangement that was further exacerbated terminally by adrenal infection and pulmonary impairment.


Sequences downstream of the transcription initiation site modulate the activity of the murine dihydrofolate reductase promoter.
The murine dihydrofolate reductase gene is regulated by a bidirectional promoter that lacks a TATA box. To identify the DNA sequences required for dihydrofolate reductase transcription, the activities of various templates were determined by in vitro transcription analysis. Our data indicate that sequences both upstream and downstream of the transcription initiation site modulate the activity of the dihydrofolate reductase promoter. We have focused on two regions downstream of the transcription initiation site that are important in determining the overall efficiency of the promoter. Region 1, which included exon 1 and part of intron 1, could stimulate transcription when placed in either orientation in the normal downstream position and when inserted upstream of the transcription start site. This region could also stimulate transcription in trans when the enhancer was physically separate from the promoter. Deletion of region 2, spanning 46 nucleotides of the 5' untranslated region, reduced transcriptional activity by fivefold. DNase I footprinting reactions identified protein-binding sites in both downstream stimulatory regions. Protein bound to two sites in region 1, both of which contain an inverted CCAAT box. The protein-binding site in the 5' untranslated region has extensive homology to binding sites in promoters that both lack (simian virus 40 late) and contain (adenovirus type 2 major late promoter and c-myc) TATA boxes.


In vitro studies with Sch 21420 and Sch 22591: activity in comparison with six other aminoglycosides and synergy with penicillin against enterococci.
In vitro tests were performed with Sch 21420 and Sch 22591 to determine (i) their activity in comparison to six other aminoglycosides against 343 clinical isolates, and (ii) whether synergy with penicillin G could be demonstrated with enterococci. In broth dilution tests, Sch 22591 was more active than the seven other aminoglycosides against Staphylococcus aureus, Enterobacteriaceae, and most nonfermenting gram-negative bacilli. Sch 22591 was as active as tobramycin against Pseudomonas aeruginosa. The activity of Sch 21420 was comparable to gentamicin, sisomicin, netilmicin, and tobramycin but greater than amikacin or kanamycin against S. aureus and most genera of Enterobacteriaceae. Sch 21420, amikacin, and kanamycin were (i) more active than the other five aminoglycosides against Proteus rettgeri and Providencia stuartii, but (ii) less active than the other five aminoglycosides against Neisseria gonorrhoeae, enterococci, most nonfermenting gram-negative bacilli, Proteus mirabilis, and Proteus morganii. Studies on the bactericidal activity of Sch 22591 with penicillin indicated a synergistic interaction against enterococci, including strains highly resistant to streptomycin and kanamycin. This could be demonstrated with combinations containing 3.0 to 6.0 mug of Sch 22591 per ml and was comparable to that observed with penicillin/gentamicin. Penicillin plus Sch 21420 (25 mug/ml) also demonstrated synergy against enterococci, including strains highly resistant to streptomycin. However, synergy did not occur against strains highly resistant to kanamycin. These latter results were similar to those obtained in tests with penicillin/kanamycin.


Postoperative stereoacuity following realignment for chronic acquired strabismus in adults.
There is controversy regarding whether or not visually mature individuals can permanently lose stereoacuity and under what conditions stereoacuity can be regained. Some have proposed a critical duration of misalignment in adults beyond which recovery of fine stereoacuity is not possible, despite successful surgical alignment. Twenty-one adult patients (median age 59 years) with large-angle acquired strabismus and who were successfully surgically aligned after 7 to 501 months of misalignment were studied. Subjects had no evidence of motor or sensory fusion since the onset of strabismus, on preoperative exam, or by history. Stereoacuity was measured using 1 or more of the Frisby, Preschool Randot and Titmus tests, at 8 weeks and at 12 months. Data from tests with monocular clues were not used. At total of 67% of patients with chronic acquired strabismus and no preoperative fusion regained measurable stereoacuity and 44% regained fine stereoacuity of at least 60 seconds of arc. Of 10 patients with no or subnormal stereoacuity 8 weeks postoperatively, 6 (60%) showed improvement at the 12-month visit. Misalignment for up to 4 years did not preclude the development of postoperative stereoacuity. Although a minority of adult strabismus patients may permanently lose stereoacuity despite successful alignment for acquired strabismus, the majority do show recovery. Such recovery of stereoacuity may take several months to occur. In our adult series, duration of misalignment did not predict failure to recover stereoacuity.


Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans.
Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (∼2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks <750 Ma. Here, on the basis of Mg and S isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end.


CGI-58/ABHD5-derived signaling lipids regulate systemic inflammation and insulin action.
Mutations of comparative gene identification 58 (CGI-58) in humans cause Chanarin-Dorfman syndrome, a rare autosomal recessive disease in which excess triacylglycerol (TAG) accumulates in multiple tissues. CGI-58 recently has been ascribed two distinct biochemical activities, including coactivation of adipose triglyceride lipase and acylation of lysophosphatidic acid (LPA). It is noteworthy that both the substrate (LPA) and the product (phosphatidic acid) of the LPA acyltransferase reaction are well-known signaling lipids. Therefore, we hypothesized that CGI-58 is involved in generating lipid mediators that regulate TAG metabolism and insulin sensitivity. Here, we show that CGI-58 is required for the generation of signaling lipids in response to inflammatory stimuli and that lipid second messengers generated by CGI-58 play a critical role in maintaining the balance between inflammation and insulin action. Furthermore, we show that CGI-58 is necessary for maximal TH1 cytokine signaling in the liver. This novel role for CGI-58 in cytokine signaling may explain why diminished CGI-58 expression causes severe hepatic lipid accumulation yet paradoxically improves hepatic insulin action. Collectively, these findings establish that CGI-58 provides a novel source of signaling lipids. These findings contribute insight into the basic mechanisms linking TH1 cytokine signaling to nutrient metabolism.


Assessing breast cancer risk in women.
Understanding modifiable and nonmodifiable factors that increase or decrease breast cancer risk allows family physicians to counsel women appropriately. Nonmodifiable factors associated with increased breast cancer risk include advanced age, female sex, family history of breast cancer, increased breast density, genetic predisposition, menarche before age 12 years, and natural menopause after age 45 years. Hormonal factors associated with breast cancer include advanced age at first pregnancy, exposure to diethylstilbestrol, and hormone therapy. Environmental factors include therapeutic radiation. Obesity is also associated with increased rates of breast cancer. Factors associated with decreased cancer rates include pregnancy at an early age, late menarche, early menopause, high parity, and use of some medications, such as selective estrogen receptor modulators and, possibly, nonsteroidal anti-inflammatory agents and aspirin. No convincing evidence supports the use of dietary interventions for the prevention of breast cancer, with the exception of limiting alcohol intake.


Probabilistic incremental program evolution
Probabilistic incremental program evolution (PIPE) is a novel technique for automatic program synthesis. We combine probability vector coding of program instructions, population-based incremental learning, and tree-coded programs like those used in some variants of genetic programming (GP). PIPE iteratively generates successive populations of functional programs according to an adaptive probability distribution over all possible programs. Each iteration, it uses the best program to refine the distribution. Thus, it stochastically generates better and better programs. Since distribution refinements depend only on the best program of the current population, PIPE can evaluate program populations efficiently when the goal is to discover a program with minimal runtime. We compare PIPE to GP on a function regression problem and the 6-bit parity problem. We also use PIPE to solve tasks in partially observable mazes, where the best programs have minimal runtime.


Effects of Nitrate Application on Amaranthus powellii Wats. : I. Changes in Photosynthesis, Growth Rates, and Leaf Area.
Physiological effects of different nitrate applications were studied using the C(4) plant, Amaranthus powellii Wats. Plants were grown in a controlled environment chamber and watered daily with nutrient solutions containing 45, 10, 5, or 1 millimolar nitrate. Chloride and sulfate were used to keep the cation and phosphate concentrations constant. Total leaf nitrogen concentration, chlorophyll concentration, specific leaf mass, leaf area, relative growth rate, relative leaf growth rate, unit leaf rate (increase of dry mass per unit leaf area per day), net photosynthetic rate, and incident quantum yield decreased with decreasing nitrate concentration. The per cent decrease of unit leaf rate was similar to the decrease of light-saturated net photosynthetic rate; however, the decrease in relative growth rate was less than that of unit leaf rate because leaf area ratio (leaf area per unit dry mass) increased with decreasing nitrate concentration. Essential mineral concentrations per unit leaf area were about equal among all treatments. Leaf expansion, determined by stomatal density, decreased except for the 1 millimolar treatment which showed relatively more cell expansion but less cell division. Decreased nitrate application was correlated with higher osmotic potentials and lower pressure potentials (determined by pressure-volume curves), whereas leaf water potentials were equal among treatments. Even though total leaf area and shoot mass decreased with decreasing applied nitrate, the increase of the leaf area ratio may be related to selection for the highest possible growth rate.


Expression of mannose receptor and ligands for its cysteine-rich domain in venous sinuses of human spleen.
The mannose receptor (MR) is a type I membrane molecule with two lectin activities. Mannose recognition takes place through the C-type lectin-like carbohydrate recognition domains, while recognition of sulphated glycans is mediated by the cysteine-rich domain (CR). In murine spleen CR ligands are present in a subpopulation of macrophages (Mphi) placed in the marginal zone whereas MR-expressing cells consisting of Mphi and nonvascular endothelia are located in the red pulp. No colocalisation of MR with CR ligands has been observed in murine tissues. In this manuscript we describe the distribution of MR and CR ligands in human spleen. In this organ we have detected a perfect colocalisation of MR with CR ligands in Lyve-1+ cells lining venous sinuses. These cells form a physical barrier for blood cells as they need to migrate through the sinuses in order to exit the splenic parenchyma and, in this way, contribute to the unique filtration function of this organ. Furthermore, unlike murine spleen, CD68+ red pulp Mphi lack MR expression. Our results suggest an unexpected contribution of MR to splenic function through the recognition of sulphated ligands that could influence the filtering capability of this organ.


Ccdc80-l1 Is involved in axon pathfinding of zebrafish motoneurons.
Axon pathfinding is a subfield of neural development by which neurons send out axons to reach the correct targets. In particular, motoneurons extend their axons toward skeletal muscles, leading to spontaneous motor activity. In this study, we identified the zebrafish Ccdc80 and Ccdc80-like1 (Ccdc80-l1) proteins in silico on the basis of their high aminoacidic sequence identity with the human CCDC80 (Coiled-Coil Domain Containing 80). We focused on ccdc80-l1 gene that is expressed in nervous and non-nervous tissues, in particular in territories correlated with axonal migration, such as adaxial cells and muscle pioneers. Loss of ccdc80-l1 in zebrafish embryos induced motility issues, although somitogenesis and myogenesis were not impaired. Our results strongly suggest that ccdc80-l1 is involved in axon guidance of primary and secondary motoneurons populations, but not in their proper formation. ccdc80-l1 has a differential role as regards the development of ventral and dorsal motoneurons, and this is consistent with the asymmetric distribution of the transcript. The axonal migration defects observed in ccdc80-l1 loss-of-function embryos are similar to the phenotype of several mutants with altered Hedgehog activity. Indeed, we reported that ccdc80-l1 expression is positively regulated by the Hedgehog pathway in adaxial cells and muscle pioneers. These findings strongly indicate ccdc80-l1 as a down-stream effector of the Hedgehog pathway.


Population Pharmacokinetic Properties of Sulfadoxine and Pyrimethamine: a Pooled Analysis To Inform Optimal Dosing in African Children with Uncomplicated Malaria.
Sulfadoxine-pyrimethamine with amodiaquine is recommended by the World Health Organization as seasonal malaria chemoprevention for children aged 3 to 59 months in the sub-Sahel regions of Africa. Suboptimal dosing in children may lead to treatment failure and increased resistance. Pooled individual patient data from four previously published trials on the pharmacokinetics of sulfadoxine and pyrimethamine in 415 pediatric and 386 adult patients were analyzed using nonlinear mixed-effects modeling to evaluate the current dosing regimen and, if needed, to propose an optimized dosing regimen for children under 5 years of age. The population pharmacokinetics of sulfadoxine and pyrimethamine were both best described by a one-compartment disposition model with first-order absorption and elimination. Body weight, age, and nutritional status (measured as the weight-for-age Z-score) were found to be significant covariates. Allometric scaling with total body weight and the maturation of clearance in children by postgestational age improved the model fit. Underweight-for-age children were found to have 15.3% and 26.7% lower bioavailabilities of sulfadoxine and pyrimethamine, respectively, for each Z-score unit below -2. Under current dosing recommendations, simulation predicted that the median day 7 concentration was below the 25th percentile for a typical adult patient (50 kg) for sulfadoxine for patients in the weight bands of 8 to 9, 19 to 24, 46 to 49, and 74 to 79 kg and for pyrimethamine for patients in the weight bands of 8 to 9, 14 to 24, and 42 to 49 kg. An evidence-based dosing regimen was constructed that would achieve sulfadoxine and pyrimethamine exposures in young children and underweight-for-age young children that were similar to those currently seen in a typical adult.


GigaSOM.jl: High-performance clustering and visualization of huge cytometry datasets.
The amount of data generated in large clinical and phenotyping studies that use single-cell cytometry is constantly growing. Recent technological advances allow the easy generation of data with hundreds of millions of single-cell data points with >40 parameters, originating from thousands of individual samples. The analysis of that amount of high-dimensional data becomes demanding in both hardware and software of high-performance computational resources. Current software tools often do not scale to the datasets of such size; users are thus forced to downsample the data to bearable sizes, in turn losing accuracy and ability to detect many underlying complex phenomena. We present GigaSOM.jl, a fast and scalable implementation of clustering and dimensionality reduction for flow and mass cytometry data. The implementation of GigaSOM.jl in the high-level and high-performance programming language Julia makes it accessible to the scientific community and allows for efficient handling and processing of datasets with billions of data points using distributed computing infrastructures. We describe the design of GigaSOM.jl, measure its performance and horizontal scaling capability, and showcase the functionality on a large dataset from a recent study. GigaSOM.jl facilitates the use of commonly available high-performance computing resources to process the largest available datasets within minutes, while producing results of the same quality as the current state-of-art software. Measurements indicate that the performance scales to much larger datasets. The example use on the data from a massive mouse phenotyping effort confirms the applicability of GigaSOM.jl to huge-scale studies.


Differential acute and chronic responses in insulin action in cultured myotubes following from nondiabetic severely obese humans following gastric bypass surgery.
Roux-en-Y gastric bypass (RYGB) surgery has been shown to induce positive metabolic adaptations for individuals with severe obesity (body mass index ≥40 kg/m2), including improved peripheral insulin action. Although a major site of insulin action, the time course changes in skeletal muscle glucose metabolism following RYGB is unclear. To investigate the acute and chronic effects of RYGB surgery on insulin-stimulated glucose metabolism in cultured human primary myotubes derived from nondiabetic severely obese humans. East Carolina University Bariatric Surgery Center and East Carolina Diabetes and Obesity Institute. Primary human skeletal muscle cells were isolated from biopsies obtained from 8 women with severe obesity before, 1 month, and 7 months following RYGB surgery. Glucose metabolism, glycogen content, and insulin signal transduction were determined in differentiated myotubes. Insulin-stimulated glycogen synthesis and glucose oxidation increased in human myotubes derived from patients with severe obesity at both 1 and 7 months post-RYGB. However, there were no alterations indicative of enhanced insulin signal transduction. At 1 month post-RYGB, muscle glycogen levels were lower (-23%) and phosphorylation of acetyl CoA carboxylase 2 (ACC2) was elevated (+16%); both returned to presurgery levels at 7 months after RYGB in myotubes derived from patients. At 7 months post-RYGB, there was an increase in peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) protein content (+54%). These data indicate that insulin action intrinsically improves in cultured human primary myotubes derived from nondiabetic severely obese patients following RYGB surgery; however, the cellular alterations involved appear to consist of distinct acute and chronic components.


Estimating variable effective population sizes from multiple genomes: a sequentially markov conditional sampling distribution approach.
Throughout history, the population size of modern humans has varied considerably due to changes in environment, culture, and technology. More accurate estimates of population size changes, and when they occurred, should provide a clearer picture of human colonization history and help remove confounding effects from natural selection inference. Demography influences the pattern of genetic variation in a population, and thus genomic data of multiple individuals sampled from one or more present-day populations contain valuable information about the past demographic history. Recently, Li and Durbin developed a coalescent-based hidden Markov model, called the pairwise sequentially Markovian coalescent (PSMC), for a pair of chromosomes (or one diploid individual) to estimate past population sizes. This is an efficient, useful approach, but its accuracy in the very recent past is hampered by the fact that, because of the small sample size, only few coalescence events occur in that period. Multiple genomes from the same population contain more information about the recent past, but are also more computationally challenging to study jointly in a coalescent framework. Here, we present a new coalescent-based method that can efficiently infer population size changes from multiple genomes, providing access to a new store of information about the recent past. Our work generalizes the recently developed sequentially Markov conditional sampling distribution framework, which provides an accurate approximation of the probability of observing a newly sampled haplotype given a set of previously sampled haplotypes. Simulation results demonstrate that we can accurately reconstruct the true population histories, with a significant improvement over the PSMC in the recent past. We apply our method, called diCal, to the genomes of multiple human individuals of European and African ancestry to obtain a detailed population size change history during recent times.


Meta-analysis of prophylactic treatments against Pneumocystis carinii pneumonia and toxoplasma encephalitis in HIV-infected patients.
In a meta-analysis, we examined the efficacy of aerosolized pentamidine, trimethoprim-sulfamethoxazole, and dapsone or dapsone/pyrimethamine for the prevention of Pneumocystis carinii pneumonia and toxoplasma encephalitis in patients with HIV infection. Of 22 trials, 13 compared trimethoprim-sulfamethoxazole with aerosolized pentamidine, nine compared dapsone alone or in combination with pyrimethamine with aerosolized pentamidine, and eight compared trimethoprim-sulfamethoxazole with dapsone/pyrimethamine. In total, 1484 patients were treated with trimethoprim-sulfamethoxazole, 1548 patients with dapsone/pyrimethamine or dapsone, and 1800 patients with aerosolized pentamidine. For dapsone/pyrimethamine versus aerosolized pentamidine, the risk ratio for P. carinii pneumonia was 0.90 (95% confidence interval [CI], 0.71-1.15), and for toxoplasma encephalitis it was 0.72 (95% CI, 0.54-0.97). For trimethoprim-sulfamethoxazole versus aerosolized pentamidine, the risk ratio of P. carinii pneumonia was 0.59 (95% CI, 0.45-0.76), and for toxoplasma encephalitis it was 0.78 (95% CI, 0.55-1.11). For trimethoprim-sulfamethoxazole versus dapsone/pyrimethamine, the risk ratio of P. carinii pneumonia was 0.49 (95% CI, 0.26-0.92), and for toxoplasma encephalitis it was 1.17 (95% CI, 0.68-2.04). Although current evidence does not allow a definitive recommendation, administration of trimethoprim-sulfamethoxazole for prophylaxis of P. carinii pneumonia and toxoplasmosis in patients with HIV infection is consistent with the available data.


SBML Level 3: an extensible format for the exchange and reuse of biological models.
Systems biology has experienced dramatic growth in the number, size, and complexity of computational models. To reproduce simulation results and reuse models, researchers must exchange unambiguous model descriptions. We review the latest edition of the Systems Biology Markup Language (SBML), a format designed for this purpose. A community of modelers and software authors developed SBML Level 3 over the past decade. Its modular form consists of a core suited to representing reaction-based models and packages that extend the core with features suited to other model types including constraint-based models, reaction-diffusion models, logical network models, and rule-based models. The format leverages two decades of SBML and a rich software ecosystem that transformed how systems biologists build and interact with models. More recently, the rise of multiscale models of whole cells and organs, and new data sources such as single-cell measurements and live imaging, has precipitated new ways of integrating data with models. We provide our perspectives on the challenges presented by these developments and how SBML Level 3 provides the foundation needed to support this evolution.


Wide variation and systematic bias in expert clinicians' perceptions of prognosis following brain injury.
The heterogeneous nature of traumatic brain injury (TBI) makes outcome prediction difficult. Although a considerable evidence base exists in the form of well-validated predictive models, these models are not widely used. We hypothesised that this prognostic gap, between the availability and use of prognostic data, leads to inaccurate perceptions of patient outcome. We investigated whether outcome predictions in TBI made by expert clinicians were consistent and accurate when compared to a well-validated prognostic model (IMPACT). Neurosurgeons and neurointensivists were asked to predict probability of death at 6 months for 12 case vignettes describing patients with isolated TBI. Predictions were compared to IMPACT prognosis for each vignette. To interrogate potential sources of bias in clinical predictions, respondents were given one of two sets of vignettes (A or B) identical apart from one critical factor known to make a large difference to outcome. 27 of 33 questionnaires were returned. Clinicians were consistently more pessimistic about outcomes than the IMPACT model, predicting a significantly greater probability of death (mean difference + 16.3%, 95% CI 13.3-19.4, p < 0.001). There was wide variation between clinicians predicting outcomes for any given vignette (mean range 68.3%), and within the predictions made by each individual: 30% of clinicians were both the most pessimistic respondent, and the most optimistic, for at least one vignette. Clinicians modified their predictions appropriately for most of the factors altered between corresponding vignettes. However when the reported blood glucose was changed, clinicians' predictions deviated widely from IMPACT predictions, indicating that clinicians systematically overlooked the prognostic relevance of this information. Clinical experts' predictions of outcome in TBI are widely variable and systematically pessimistic compared to IMPACT. Clinicians overlook important factors in formulating these predictions. Use of well-validated outcome models may add value and consistency to prognostication.


The CD4-independent tropism of human immunodeficiency virus type 2 involves several regions of the envelope protein and correlates with a reduced activation threshold for envelope-mediated fusion.
Several human immunodeficiency virus type 2 (HIV-2) strains have been shown to infect some CD4-negative cell lines (P. R. Clapham, A. McKnight, and R. A. Weiss, J. Virol. 66:3531-3537, 1992). Using molecular clones of HIV-2 with a CD4-independent tropism, we have identified critical amino acid residues in the envelope protein which are required for CD4-independent infection. Mutations located immediately upstream of a proposed coiled coil domain in the transmembrane protein (A526T or I528M) and flanking the base of the V4 loop (L378F and K403R) are crucial for the CD4-independent phenotype. Of several mutations conferring a positive charge in V1, V2, and V3, only the change in V3 (Q310K) helped to enhance the CD4-independent phenotype but could not mediate it on its own. These mutations reduce the amount of soluble CD4 required to trigger CD4-independent cell-cell fusion, suggesting that they lower the activation threshold for the fusion process. After binding to cell surface-anchored CD4, a CD4-independent recombinant envelope protein showed an increased binding of anti-envelope protein antibodies, suggesting either an enhanced binding to cell surfaces or more extensive conformational changes in CD4-independent compared to CD4-dependent envelope proteins. The reduced activation threshold of CD4-independent envelope proteins may thus enable them to utilize a membrane molecule for entry which is not as efficient as CD4 in triggering the conformational changes required for the membrane fusion process. CD4-independent HIV-2 variants may be conceptually similar to influenza virus variants capable of fusing at a higher than normal pH (R. S. Daniels, J. C. Downie, J. A. Hay, M. Knossow, J. J. Skehel, M. L. Wang, and D. C. Wiley, Cell 40:431-439, 1985).


Fondaparinux in the management of patients with ST-elevation acute myocardial infarction.
The death rate of patients with ST-segment elevation myocardial infarction (STEMI) remains substantial. Fondaparinux is a synthetic selective Factor Xa inhibitor with a high efficacy and good safety, in terms of bleeding risk, in the prevention and treatment of venous thromboembolism, and in the treatment of non-ST elevation acute coronary syndromes (OASIS-5). The OASIS-6 trial was a randomized, double-blind trial comparing fondaparinux 2.5 mg once daily with standard therapy, either placebo or unfractionated heparin according to the indication, in 12092 patients with STEMI. At day 30, fondaparinux significantly reduced the occurrence of the primary efficacy outcome (death or recurrent myocardial infarction) by 14% (p = 0.008). Consistent reductions in both death and recurrent MI were observed at 6-month follow-up. The benefits were significant in patients who received no reperfusion therapy or a thrombolytic agent, but not in patients undergoing primary percutaneous coronary interventions. There was a trend (p = 0.13) towards fewer severe bleeds in the fondaparinux group (1.0% vs 1.3% in the control group). In conclusion, fondaparinux significantly reduced mortality without increasing severe bleeding in patients with STEMI. Overall, the data from the OASIS studies showed that fondaparinux 2.5 mg may represent a new anticoagulant standard in patients with acute coronary syndromes.


A Day Awake Attenuates Motor Learning-Induced Increases in Corticomotor Excitability.
The "synaptic homeostasis hypothesis" proposes that the brain's capacity to exhibit synaptic plasticity is reduced during the day but restores when sleeping. While this prediction has been confirmed for declarative memories, it is currently unknown whether it is also the case for motor memories. We quantified practice-induced changes in corticomotor excitability in response to repetitive motor sequence training as an indirect marker of synaptic plasticity in the primary motor cortex (M1). Subjects either practiced a motor sequence in the morning and a new motor sequence in the evening, i.e., after a 12 h period of wakefulness (wake group); or they practiced a sequence in the evening and a new sequence in the morning, i.e., after a 12 h period including sleep (sleep group). In both wake and sleep groups motor training improved movement performance irrespective of the time of day. Learning a new sequence in the morning triggered a clear increase in corticomotor excitability suggesting that motor training triggered synaptic adaptation in the M1 that was absent when a new sequence was learned in the evening. Thus, the magnitude of the practice-induced increase in corticomotor excitability was significantly influenced by time of day while the magnitude of motor performance improvements were not. These results suggest that the motor cortex's potential to efficiently adapt to the environment by quickly adjusting synaptic strength in an activity-dependent manner is higher in the morning than in the evening.


Primary hyperparathyroidism: review and recommendations on evaluation, diagnosis, and management. A Canadian and international consensus.
The purpose of this review is to assess the most recent evidence in the management of primary hyperparathyroidism (PHPT) and provide updated recommendations for its evaluation, diagnosis and treatment. A Medline search of "Hyperparathyroidism. Primary" was conducted and the literature with the highest levels of evidence were reviewed and used to formulate recommendations. PHPT is a common endocrine disorder usually discovered by routine biochemical screening. PHPT is defined as hypercalcemia with increased or inappropriately normal plasma parathyroid hormone (PTH). It is most commonly seen after the age of 50 years, with women predominating by three to fourfold. In countries with routine multichannel screening, PHPT is identified earlier and may be asymptomatic. Where biochemical testing is not routine, PHPT is more likely to present with skeletal complications, or nephrolithiasis. Parathyroidectomy (PTx) is indicated for those with symptomatic disease. For asymptomatic patients, recent guidelines have recommended criteria for surgery, however PTx can also be considered in those who do not meet criteria, and prefer surgery. Non-surgical therapies are available when surgery is not appropriate. This review presents the current state of the art in the diagnosis and management of PHPT and updates the Canadian Position paper on PHPT. An overview of the impact of PHPT on the skeleton and other target organs is presented with international consensus. Differences in the international presentation of this condition are also summarized.


Diagnosis and treatment of dementia: 1. Risk assessment and primary prevention of Alzheimer disease.
In addition to nonmodifiable genetic risk factors, potentially modifiable factors such as hypertension, hyperlipidemia and environmental exposures have been identified as risk factors for Alzheimer disease. In this article, we provide physicians with practical guidance on risk assessment and primary prevention of Alzheimer disease based on recommendations from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, held in March 2006. We developed evidence-based guidelines using systematic literature searches, with specific criteria for study selection and quality assessment, and a clear and transparent decision-making process. We selected studies published from January 1996 to December 2005 that met the following criteria: dementia (all-cause, Alzheimer disease or vascular dementia) as the outcome; longitudinal cohort study; study population broadly reflective of Canadian demographics; and genetic risk factors and general risk factors (e.g., hypertension, education, occupation and chemical exposure) identified. We graded the strength of evidence using the criteria of the Canadian Task Force on Preventive Health Care. Of 3424 articles on potentially modifiable risk factors for dementia, 1719 met our inclusion criteria; 60 were deemed to be of good or fair quality. Of 1721 articles on genetic risk factors, 62 that met our inclusion criteria were deemed to be of good or fair quality. On the basis of evidence from these articles, we made recommendations for the risk assessment and primary prevention of Alzheimer disease. For the primary prevention of Alzheimer's disease, there is good evidence for controlling vascular risk factors, especially hypertension (grade A), and weak or insufficient evidence for manipulation of lifestyle factors and prescribing of medications (grade C). There is good evidence to avoid estrogens and high-dose (> 400 IU/d) of vitamin E for this purpose (grade E). Genetic counselling and testing may be offered to at-risk individuals with an apparent autosomal dominant inheritance (grade B). Screening for the apolipoprotein E genotype in asymptomatic individuals in the general population is not recommended (grade E). Despite the personal and societal burden of dementia, our understanding of genetic predisposition to dementias and the contribution of other risk factors remains limited. More importantly, there are few data to explain the overall risks and benefits of prevention strategies or their impact of risk modification.


Developmental psychopathology of children and adolescents with Tourette syndrome--impact of ADHD.
In Tourette syndrome (TS) as a neurodevelopmental disorder not only the tics but also the comorbid conditions change with increasing age. ADHD is highly comorbid with TS and usually impairs psychosocial functioning more than the tics. Its impact on further comorbidity during development is important for clinical practice and still a matter of debate. Aspects of developmental psychopathology considering the impact of ADHD were examined by logistic regression (year wisely) in a cross-sectional sample of children and adolescents (n = 5060) from the TIC database. In TS+ADHD (compared to TS-ADHD) higher rates of comorbid conditions like OCD, anxiety disorders, CD/ODD and mood disorders were found in children (5-10 years). In adolescents (11-17 years) higher comorbidity rates in TS+ADHD remained only for CD/ODD and mood disorders. Accordingly, for OCD and anxiety disorders there was a steeper year wise increase of these comorbidities in TS-ADHD while it was a similar for CD/ODD and mood disorders in TS-ADHD as well as TS+ADHD. Children with TS+ADHD have more comorbidities than the TS-ADHD group, whereas in both adolescent groups this did no longer hold for OCD and anxiety disorders. These findings indicate that in TS comorbid ADHD is associated with high rates of externalizing and internalizing problems, whereas TS without ADHD is associated only with internalizing problems in adolescence.