Knockout of the S-acyltransferase Gene, PbPAT14, Confers the Dwarf Yellowing Phenotype in First Generation Pear by ABA Accumulation.
The development of dwarf fruit trees with smaller and compact characteristics leads to significantly increased fruit production, which is a major objective of pear (Pyrus bretschneideri) breeding. We identified the S-acylation activity of PbPAT14, an S-acyltransferase gene related to plant development, using a yeast (Saccharomyces cerevisiae) complementation assay, and also PbPAT14 could rescue the growth defect of the Arabidopsis mutant atpat14. We further studied the function of PbPAT14 by designing three guide RNAs for PbPAT14 to use in the CRISPR/Cas9 system. We obtained 22 positive transgenic pear lines via Agrobacterium-mediated transformation using cotyledons from seeds of Pyrus betulifolia ('Duli'). Six of these lines exhibited the dwarf yellowing phenotype and were homozygous mutations according to sequencing analysis. Ultrastructure analysis suggested that this dwarfism was manifested by shorter, thinner stems due to a reduction in cell number. A higher level of endogenous abscisic acid (ABA) and a higher transcript level of the ABA pathway genes in the mutant lines revealed that the PbPAT14 function was related to the ABA pathway. Overall, our experimental results increase the understanding of how PATs function in plants and help elucidate the mechanism of plant dwarfism.


Potential role of endothelial progenitor cells in the pathophysiology of heart failure: clinical implications and perspectives.
Endothelial dysfunction is thought to play a major role in the development and clinical complications of heart failure. Endothelial progenitor cells (EPCs) have been shown to provide an endogenous repair mechanism to counteract detrimental risk factor-induced effects and replace dysfunctional endothelium. The number and in vitro function of EPCs is altered in patients with heart failure, as a result of its pathophysiological mechanisms. EPCs could represent a substitutional marker to guide preventive or therapeutic interventions in this disease. Enhancing the number and functional capacity of EPCs with targeted interventions may elicit functional improvement in individuals with heart failure. However, the exact role of EPCs in heart failure and their potential therapeutic implications still remain to be elucidated.


Electrochemistry of layered GaSe and GeS: applications to ORR, OER and HER.
Though many studies examined the properties of the class of IIIA-VIA and IVA-VIA layered materials, few have delved into the electrochemical aspect of such materials. In light of the burgeoning interest in layered structures towards various electrocatalytic applications, we endeavored to study the inherent electrochemical properties of representative layered materials of this class, GaSe and GeS, and their impact towards electrochemical sensing of redox probes as well as catalysis of oxygen reduction, oxygen evolution and hydrogen evolution reactions. In contrast to the typical sandwich structure of MoS2 layered materials, GeS is isoelectronic to black phosphorus with the same structure; GaSe is a layered material consisting of GaSe sheets bonded in the sequence Se-Ga-Ga-Se. We characterized GaSe and GeS by employing scanning electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy complemented by electronic structure calculations. It was found that the encompassing surface oxide layers on GaSe and GeS greatly influenced their electrochemical properties, especially their electrocatalytic capabilities towards hydrogen evolution reaction. These findings provide fresh insight into the electrochemical properties of these IIIA-VIA and IVA-VIA layered structures which enables development for future applications.


Uptake of mevalonate and acetate during plastid development.
1. The envelopes of etioplasts and 1-2h etiochloroplasts are permeable to mevalonate, but plastids from etiolated tissue illuminated for longer than 4h show progressive impermeability towards mevalonate. 2. Acetate permeates the envelopes of 1-4h etiochloroplasts but does not significantly cross the envelopes of etioplasts or 8-24h etiochloroplasts. 3. A translocator system exists within the plastid envelopes for mevalonate which relies on malate as a counter-exchange anion.


Molecular cloning and physical mapping of murine cytomegalovirus DNA.
Murine cytomegalovirus (MCMV) Smith strain DNA is cleaved by restriction endonuclease HindIII into 16 fragments, ranging in size from 0.64 to 22.25 megadaltons. Of the 16 HindIII fragments, 15 were cloned in plasmid pACYC177 in Escherichia coli HB101 (recA). The recombinant plasmid clones were characterized by cleavage with the enzymes XbaI and EcoRI. In addition, fragments generated by double digestion of cloned fragments with HindIII and XbaI were inserted into the plasmid vector pACYC184. The results obtained after hybridization of 32P-labeled cloned fragments to Southern blots of MCMV DNA cleaved with HindIII, XbaI, EcoRI, BamHI, ApaI, ClaI, EcoRV, or KpnI allowed us to construct complete physical maps of the viral DNA for the restriction endonucleases HindIII, XbaI, and EcoRI. On the basis of the cloning and mapping experiments, it was calculated that the MCMV genome spans about 235 kilobase pairs, corresponding to a molecular weight of 155,000,000. All fragments were found to be present in equimolar concentrations, and no cross-hybridization between any of the fragments was seen. We conclude that the MCMV DNA molecule consists of a long unique sequence without large terminal or internal repeat regions. Thus, the structural organization of the MCMV genome is fundamentally different from that of the human cytomegalovirus or herpes simplex virus genome.


The Affordable Care Act's Coverage Impacts in the Trump Era.
The 2016 US presidential election created uncertainty about the future of the Affordable Care Act (ACA) and led to postponed implementation of certain provisions, reduced funding for outreach, and the removal of the individual mandate tax penalty. In this article, we estimate how the causal impact of the ACA on insurance coverage changed during 2017 through 2019, the first 3 years of the Trump administration, compared to 2016. Data come from the 2011-2019 waves of the American Community Survey (ACS), with the sample restricted to non-elderly adults. Our model leverages variation in treatment intensity from state Medicaid expansion decisions and pre-ACA uninsured rates. We find that the coverage gains from the components of the law that took effect nationally-such as the individual mandate and regulations and subsidies in the private non-group market-fell from 5 percentage points in 2016 to 3.6 percentage points in 2019. In contrast, the coverage gains from the Medicaid expansion increased in 2017 (7.0 percentage points) before returning to the 2016 level of coverage gains in 2019 (5.9 percentage points). The net effect of the ACA in expansion states is a combination of these trends, with coverage gains falling from 10.8 percentage points in 2016 to 9.6 percentage points in 2019.


COVID-19 Infection: Implications for Perioperative and Critical Care Physicians.
Healthcare systems worldwide are responding to Coronavirus Disease 2019 (COVID-19), an emerging infectious syndrome caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus. Patients with COVID-19 can progress from asymptomatic or mild illness to hypoxemic respiratory failure or multisystem organ failure, necessitating intubation and intensive care management. Healthcare providers, and particularly anesthesiologists, are at the frontline of this epidemic, and they need to be aware of the best available evidence to guide therapeutic management of patients with COVID-19 and to keep themselves safe while doing so. Here, the authors review COVID-19 pathogenesis, presentation, diagnosis, and potential therapeutics, with a focus on management of COVID-19-associated respiratory failure. The authors draw on literature from other viral epidemics, treatment of acute respiratory distress syndrome, and recent publications on COVID-19, as well as guidelines from major health organizations. This review provides a comprehensive summary of the evidence currently available to guide management of critically ill patients with COVID-19.


Impairment of bidirectional synaptic plasticity in the striatum of a mouse model of DYT1 dystonia: role of endogenous acetylcholine.
DYT1 dystonia is a severe form of inherited dystonia, characterized by involuntary twisting movements and abnormal postures. It is linked to a deletion in the dyt1 gene, resulting in a mutated form of the protein torsinA. The penetrance for dystonia is incomplete, but both clinically affected and non-manifesting carriers of the DYT1 mutation exhibit impaired motor learning and evidence of altered motor plasticity. Here, we characterized striatal glutamatergic synaptic plasticity in transgenic mice expressing either the normal human torsinA or its mutant form, in comparison to non-transgenic (NT) control mice. Medium spiny neurons recorded from both NT and normal human torsinA mice exhibited normal long-term depression (LTD), whereas in mutant human torsinA littermates LTD could not be elicited. In addition, although long-term potentiation (LTP) could be induced in all the mice, it was greater in magnitude in mutant human torsinA mice. Low-frequency stimulation (LFS) can revert potentiated synapses to resting levels, a phenomenon termed synaptic depotentiation. LFS induced synaptic depotentiation (SD) both in NT and normal human torsinA mice, but not in mutant human torsinA mice. Since anti-cholinergic drugs are an effective medical therapeutic option for the treatment of human dystonia, we reasoned that an excess in endogenous acetylcholine could underlie the synaptic plasticity impairment. Indeed, both LTD and SD were rescued in mutant human torsinA mice either by lowering endogenous acetylcholine levels or by antagonizing muscarinic M1 receptors. The presence of an enhanced acetylcholine tone was confirmed by the observation that acetylcholinesterase activity was significantly increased in the striatum of mutant human torsinA mice, as compared with both normal human torsinA and NT littermates. Moreover, we found similar alterations of synaptic plasticity in muscarinic M2/M4 receptor knockout mice, in which an increased striatal acetylcholine level has been documented. The loss of LTD and SD on one hand, and the increase in LTP on the other, demonstrate that a 'loss of inhibition' characterizes the impairment of synaptic plasticity in this model of DYT1 dystonia. More importantly, our results indicate that an unbalanced cholinergic transmission plays a pivotal role in these alterations, providing a clue to understand the ability of anticholinergic agents to restore motor deficits in dystonia.


Use of a crop and job specific exposure matrix for estimating cumulative exposure to triazine herbicides among females in a case-control study in the Central Valley of California.
To determine if a job exposure matrix (JEM) could be developed using the California Department of Pesticide Regulation Pesticide Usage Database in conjunction with crop, time, and county specific self reported work history and to determine if this was a feasible method to obtain exposure estimates to triazine herbicides. Agricultural work histories were gathered from women enrolled in a population based case-control study of ovarian cancer cases and random controls. The work histories were used in conjunction with the database to construct job exposure matrices which took into account weightings for job type, work location, and crop. Cumulative exposure estimates were determined for 98 study subjects. Mean exposure estimates were similar for cases and controls. The exposure estimates were robust and insensitive to varying job weight assumptions. The estimates from the original weights were highly correlated with those constructed using the conservative and maximum weights. Estimates from all three schemes produced similar multivariate age adjusted odds ratios comparing cases and controls. There was a high degree of agreement in categorised quartiles of exposure between the original and conservative, and original and maximum weights. The exposure estimate from the JEM provides a ranking of exposure within the study population that can be utilised as an "exposure score" with which to compare groups. Although it is not an absolute exposure measurement, it does offer a substantial advance over dichotomous categories based on self report of herbicide use, particularly when subjects are unlikely to recall specific names and dates of use of herbicides.


Detection of single photons by toad and mouse rods.
Amphibian and mammalian rods can both detect single photons of light even though they differ greatly in physical dimensions, mammalian rods being much smaller in diameter than amphibian rods. To understand the changes in physiology and biochemistry required by such large differences in outer segment geometry, we developed a computational approach, taking into account the spatial organization of the outer segment divided into compartments, together with molecular dynamics simulations of the signaling cascade. We generated simulations of the single-photon response together with intrinsic background fluctuations in toad and mouse rods. Combining this computational approach with electrophysiological data from mouse rods, we determined key biochemical parameters. On average around one phosphodiesterase (PDE) molecule is spontaneously active per mouse compartment, similar to the value for toad, which is unexpected due to the much smaller diameter in mouse. A larger number of spontaneously active PDEs decreases dark noise, thereby improving detection of single photons; it also increases cGMP turnover, which accelerates the decay of the light response. These constraints explain the higher PDE density in mammalian compared with amphibian rods that compensates for the much smaller diameter of mammalian disks. We further find that the rate of cGMP hydrolysis by light-activated PDE is diffusion limited, which is not the case for spontaneously activated PDE. As a consequence, in the small outer segment of a mouse rod only a few activated PDEs are sufficient to generate a signal that overcomes noise, which permits a shorter lifetime of activated rhodopsin and greater temporal resolution.


Volume Loss and Recovery in Bovine Knee Meniscus Loaded in Circumferential Tension.
Load-induced volume change is an important aspect of knee meniscus function because volume loss creates fluid pressure, which minimizes friction and helps support compressive loads. The knee meniscus is unusual amongst cartilaginous tissues in that it is loaded not only in axial compression, but also in circumferential tension between its tibial attachments. Despite the physiologic importance of the knee meniscus' tensile properties, its volumetric strain in tension has never been directly measured, and predictions of volume strain in the scientific literature are inconsistent. In this study, we apply uniaxial tension to bovine knee meniscus and use biplanar imaging to directly observe the resulting three-dimensional volume change and unloaded recovery, revealing that tension causes volumetric contraction. Compression is already known to also cause contraction; therefore, all major physiologic loads compress and pressurize the meniscus, inducing fluid outflow. Although passive unloaded recovery is often described as slow relative to loaded loss, here we show that at physiologic strains the volume recovery rate in the meniscus upon unloading is faster than the rate of volume loss. These measurements of volumetric strain are an important step toward a complete theory of knee meniscus fluid flow and load support.


Area postrema ablation and vascular reactivity in deoxycorticosterone-salt-treated rats.
In rats, central administration of the neurotoxin 6-hydroxydopamine prevents hypertension and certain functional vascular changes after deoxycorticosterone (DOC)-salt treatment. In this study, the effect of electrolytic ablation of the area postrema on blood pressure and vascular reactivity in DOC-salt-treated rats was examined. Four treatment groups of rats were studied (n = 5 in each): area postrema lesion, DOC-salt (DOC pivalate, 5 mg/wk s.c. for 5 weeks); sham lesion, DOC-salt; area postrema lesion, control; and sham lesion, control. Helically cut strips of carotid artery, aorta, and mesenteric artery were prepared for isometric force recording. Area postrema lesion attenuated hypertension in DOC-salt rats (mean arterial pressure, 107 vs 123 mm Hg in area postrema lesion and sham lesion rats, respectively; chronic aortic catheter). Vascular strips from sham lesion-control rats. These changes in vascular reactivity also were observed in area postrema lesion-DOC-salt rats. DOC treatment in rats on a normal sodium intake did not result in hypertension or increased vascular reactivity. In summary, integrity of the area postrema is necessary for hypertension but not for changes in vascular reactivity, in DOC-salt rats. It appears that 1) changes in vascular reactivity may be necessary, but they are not sufficient to produce DOC-salt hypertension, and 2) if these vascular changes are secondary to a central nervous system effect, they are mediated by a pathway distinct from the area postrema.


A global assessment of marine heatwaves and their drivers.
Marine heatwaves (MHWs) can cause devastating impacts to marine life. Despite the serious consequences of MHWs, our understanding of their drivers is largely based on isolated case studies rather than any systematic unifying assessment. Here we provide the first global assessment under a consistent framework by combining a confidence assessment of the historical refereed literature from 1950 to February 2016, together with the analysis of MHWs determined from daily satellite sea surface temperatures from 1982-2016, to identify the important local processes, large-scale climate modes and teleconnections that are associated with MHWs regionally. Clear patterns emerge, including coherent relationships between enhanced or suppressed MHW occurrences with the dominant climate modes across most regions of the globe - an important exception being western boundary current regions where reports of MHW events are few and ocean-climate relationships are complex. These results provide a global baseline for future MHW process and prediction studies.


Transcribing RNA polymerase II is phosphorylated at CTD residue serine-7.
RNA polymerase II is distinguished by its large carboxyl-terminal repeat domain (CTD), composed of repeats of the consensus heptapeptide Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7. Differential phosphorylation of serine-2 and serine-5 at the 5' and 3' regions of genes appears to coordinate the localization of transcription and RNA processing factors to the elongating polymerase complex. Using monoclonal antibodies, we reveal serine-7 phosphorylation on transcribed genes. This position does not appear to be phosphorylated in CTDs of less than 20 consensus repeats. The position of repeats where serine-7 is substituted influenced the appearance of distinct phosphorylated forms, suggesting functional differences between CTD regions. Our results indicate that restriction of serine-7 epitopes to the Linker-proximal region limits CTD phosphorylation patterns and is a requirement for optimal gene expression.


CCR5 deletion mutation and its association with the risk of developing acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.
Recently published data have suggested a potential role of CC chemokine receptor-5 (CCR5) in a mouse model of graft-versus-host disease (GvHD). It has also been described that a 32-nucleotide deletion within the CCR5 gene (CCR5Delta32) leads to complete loss of functional CCR5 in subjects homozygous for this mutation and decreased expression in heterozygous individuals. We analyzed CCR5 genotypes and their relationship to transplant outcome. A total of 349 individuals, comprising 186 recipients and 163 donors of allogeneic hematopoietic stem cell transplants, were typed for CCR5 polymorphisms. Recipients carrying the CCR5Delta32 allele developed acute GvHD (grades I-IV) less frequently than did patients lacking the CCR5 deletion mutation (11/35 vs. 76/151, p=0.033). This association was still valid after correcting for other known variables (recipient age, donor-recipient gender relation, type of donor, conditioning regimen, diagnosis, stem cell source and GvHD prophylaxis) by logistic regression (OD=0.391, p=0.023). Transplantation from a donor other than a matched sibling (OD=2.007, p=0.028), recipient age (OD=2.117, p=0.041) and myeloablative conditioning regimen (OD=2.235, p=0.014) were found to be factors associated with an increased risk of GvHD. Moreover, acute GvHD symptoms were not observed in any of the recipients carrying the CCR5Delta32 allele transplanted from donors with this deletion mutation (0/11 vs. 70/151, p=0.002). The presence of the CCR5Delta32 allele in recipients constituted an independent and protective factor associated with a decreased risk of GvHD. This protective effect of the CCR5 deletion mutation was particularly marked in patients transplanted from donors also carrying the CCR5Delta32 allele.


Variation in post-TAVR antiplatelet therapy utilization and associated outcomes: Insights from the STS/ACC TVT Registry.
Dual antiplatelet therapy (DAPT) is recommended following transcatheter aortic valve replacement (TAVR); however, the optimal antiplatelet strategy is undefined, and little is known about practice patterns. We aimed to describe contemporary practice patterns of antiplatelet therapy and their relationship to outcomes post-TAVR. The population was derived from the National Cardiovascular Data Registry, Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry with Center for Medical Services linkage for 1-year outcomes from October 1, 2011 to June 30,2016. The primary outcome measured was DAPT use in patients without anticoagulation. Secondary outcomes included death, major bleeding, myocardial infarction (MI), and stroke at 1 year. Overall, 16,694 patients underwent transfemoral TAVR at 444 hospitals and were discharged without anticoagulation. Among these, 13,546 (81.1%) patients were discharged on DAPT, whereas 3,148 patients (18.9%) were discharged on monotherapy. Patients discharged on DAPT versus monotherapy were similar in age, sex, and most comorbid illnesses but had higher rates of coronary artery disease (64.6% vs 52.3%; P < .01) and peripheral artery disease (25.2% vs 22.3%; P < .01). Hospital prescribing patterns varied significantly (median frequency of DAPT 85.7%, interquartile range 94.1%-74.2%). DAPT (vs monotherapy) patients had a similar mortality risk at 1 year (adjusted hazard ratio 0.92, 95% CI 0.81-1.05), significantly higher risk for major bleeding (1.48, 1.10-1.99), and similar hazard for stroke (1.04, 0.83-1.31) and MI (1.00, 0.72-1.39). In the United States, most patients were discharged on DAPT following TAVR. Practice patterns varied significantly among hospitals. Patients discharged with DAPT had a similar adjusted risk of mortality, stroke, and MI compared to antiplatelet monotherapy, although risk for bleeding was significantly higher. Future investigation is needed to define the optimal antiplatelet therapy for patients undergoing TAVR.


Spectral imaging toolbox: segmentation, hyperstack reconstruction, and batch processing of spectral images for the determination of cell and model membrane lipid order.
Spectral imaging with polarity-sensitive fluorescent probes enables the quantification of cell and model membrane physical properties, including local hydration, fluidity, and lateral lipid packing, usually characterized by the generalized polarization (GP) parameter. With the development of commercial microscopes equipped with spectral detectors, spectral imaging has become a convenient and powerful technique for measuring GP and other membrane properties. The existing tools for spectral image processing, however, are insufficient for processing the large data sets afforded by this technological advancement, and are unsuitable for processing images acquired with rapidly internalized fluorescent probes. Here we present a MATLAB spectral imaging toolbox with the aim of overcoming these limitations. In addition to common operations, such as the calculation of distributions of GP values, generation of pseudo-colored GP maps, and spectral analysis, a key highlight of this tool is reliable membrane segmentation for probes that are rapidly internalized. Furthermore, handling for hyperstacks, 3D reconstruction and batch processing facilitates analysis of data sets generated by time series, z-stack, and area scan microscope operations. Finally, the object size distribution is determined, which can provide insight into the mechanisms underlying changes in membrane properties and is desirable for e.g. studies involving model membranes and surfactant coated particles. Analysis is demonstrated for cell membranes, cell-derived vesicles, model membranes, and microbubbles with environmentally-sensitive probes Laurdan, carboxyl-modified Laurdan (C-Laurdan), Di-4-ANEPPDHQ, and Di-4-AN(F)EPPTEA (FE), for quantification of the local lateral density of lipids or lipid packing. The Spectral Imaging Toolbox is a powerful tool for the segmentation and processing of large spectral imaging datasets with a reliable method for membrane segmentation and no ability in programming required. The Spectral Imaging Toolbox can be downloaded from https://uk.mathworks.com/matlabcentral/fileexchange/62617-spectral-imaging-toolbox .


The use of a deuterium tracer technique to follow the fate of fluids ingested by human subjects: effects of drink volume and tracer concentration and content.
Deuterium oxide (2H2O) has been added to drinks as a tracer for water to estimate the availability to the body water pool of ingested fluids, but doubts have been raised as to the reliability of the method. The present investigation evaluated the effects of systematic variations in the volume of fluid consumed and the amount and concentration of added tracer on the rate of accumulation of tracer in arterialized blood after ingestion of a labelled drink. Three separate experiments were undertaken. In expt 1, six healthy men ingested on separate occasions 200, 400 and 800 ml of a dilute glucose-electrolyte solution: all test drinks contained the same concentration (40 g l-1) of 2H2O. In expt 2, six healthy men ingested 200, 400 and 800 ml of the same glucose-electrolyte drink: each drink contained 8 g of 2H2O so that the concentration, but not the amount, of 2H2O differed between treatments. In expt 3, six healthy men ingested 400 ml of the same drink on three separate occasions: each drink contained 8, 16 or 32 g of tracer so that amount and concentration of 2H2O both varied. Arterialized venous blood samples were collected for the determination of deuterium (2H) concentration before ingestion of the test drink and at intervals for 120 min after ingestion. All trials for each of the experiments were conducted in the morning after an overnight fast and trials were in randomized order and separated by 7 days. In expt 1, the blood 2H concentration at all time points from 2 min after ingestion of the test drink onwards was higher for the drink containing 32 g 2H2O than for the drink containing 16 g 2H2O, which in turn was higher than after ingestion of the drink containing 8 g of 2H2O. In expt 2, no significant differences between treatments were observed at any time. In expt 3, the rate of 2H accumulation was greater after ingestion of the drink containing 32 g of 2H2O than after either of the other two drinks, and the 2H accumulation rate was greater after ingestion of the drink containing 16 g of 2H2O than after the drink containing 8 g of 2H2O. When data from all three experiments were combined, significant correlations were observed between the rate of accumulation of 2H in the circulation (p.p.m. min-1) and the amount (rs = 0.75, P < 0001) and concentration (rs = 0.69, P < 0001) of 2H2O in the test drink, but there was no relationship (rs = 0.09, P = 0.5) between the rate of 2H accumulation in the blood and the volume of the drink consumed. The results suggest that the rate of tracer accumulation in the blood after ingestion of different volumes of test drinks is not a reliable indication of the availability of the ingested fluid, but that the method gives at least a qualitative measure of the sum of the effects of gastric emptying and intestinal water absorption.


Rapid expansion of the physical and genetic map of the chromosome of Clostridium perfringens CPN50.
The physical map of the 3.6-megabase chromosome of Clostridium perfringens CPN50 was extended by positioning sites for the endonucleases SfiI and I-CeuI, and in parallel, the gene map was expanded by using a genome scanning strategy. This involved the cloning and sequencing of random chromosomal fragments, identification of the functions of the putative genes by database searches, and then hybridization analysis. The current gene map comprises almost 100 markers, many of which encode housekeeping functions while others are involved in sporulation or pathogenesis. Strikingly, most of the virulence genes were found to be confined to a 1,200-kb segment of the chromosome near oriC, while the pleiotropic regulatory locus, virRS, was situated toward the putative replication terminus. A comparison of the gene maps of three endospore-forming bacilli, C. perfringens, Clostridium beijerinckii, and Bacillus subtilis, revealed a similar order and distribution of key sporulation and heat shock genes which might reflect an ancient evolutionary relationship.


Occupational exposures and head and neck cancers among Swedish construction workers.
Occupational exposures in the construction industry may increase the risk of head and neck cancers, although the epidemiologic evidence is limited by problems of low study power and inadequate adjustment for tobacco use. In an attempt to address this issue, the relationship between selected occupational exposures and head and neck cancer risk was investigated using data from a large cohort of Swedish construction workers. Altogether 510 squamous cell carcinomas of the head and neck (171 in the oral cavity, 112 in the pharynx, 227 in the larynx) were identified during 1971-2001 among 307 799 male workers in the Swedish construction industry. Exposure to diesel exhaust, asbestos, organic solvents, metal dust, asphalt, wood dust, stone dust, mineral wool, and cement dust was assessed using a semi-quantitative job-exposure matrix. Rate ratios (RR) and 95% confidence intervals (95% CI) were calculated for head and neck cancers in relation to occupational exposure, using Poisson regression with adjustment for age and smoking status. Asbestos exposure was related to an increased laryngeal cancer incidence (RR 1.9, 95% CI 1.2-3.1). Excesses of pharyngeal cancer were observed among workers exposed to cement dust (RR 1.9, 95% CI 1.2-3.1). No occupational exposures were associated with oral cavity cancer. These findings did not materially change upon additional adjustment for cigarette pack-years. These findings offer further evidence that asbestos increases the risk of laryngeal cancer. The observation of a positive association between cement dust exposure and pharyngeal cancer warrants further investigation.


De novo design of a transmembrane Zn²⁺-transporting four-helix bundle.
The design of functional membrane proteins from first principles represents a grand challenge in chemistry and structural biology. Here, we report the design of a membrane-spanning, four-helical bundle that transports first-row transition metal ions Zn(2+) and Co(2+), but not Ca(2+), across membranes. The conduction path was designed to contain two di-metal binding sites that bind with negative cooperativity. X-ray crystallography and solid-state and solution nuclear magnetic resonance indicate that the overall helical bundle is formed from two tightly interacting pairs of helices, which form individual domains that interact weakly along a more dynamic interface. Vesicle flux experiments show that as Zn(2+) ions diffuse down their concentration gradients, protons are antiported. These experiments illustrate the feasibility of designing membrane proteins with predefined structural and dynamic properties.


Direct identification of bacterial isolates in blood cultures by using a DNA probe.
This study involved the rapid, direct identification of Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Haemophilus influenzae, Enterococcus sp., and Streptococcus agalactiae from positive blood culture bottles (BACTEC, Johnston Laboratories, Inc.) by using the AccuProbe (Gen-Probe, San Diego, Calif.) culture confirmation test. This method uses a chemiluminescent DNA probe that detects the rRNA of the target organisms. The manufacturer's instructions were modified to use a pellet of bacteria made directly from positive blood culture broth rather than a colony from an agar plate. Two separate procedures of selective centrifugation were employed in order to obtain the pellet. The first utilized a routine clinical centrifuge and a large volume of broth (10 to 12 ml) from the blood culture bottle. The second method used a microcentrifuge and less volume (1 to 1.5 ml). A total of 196 clinical specimens taken directly from positive blood culture broths were correctly identified by AccuProbe from pellets made by using the clinical centrifuge technique, while 166 clinical specimens used as negative controls failed to show hybridization. The microcentrifuge technique for obtaining pellets was performed on 105 patient specimens, and all were correctly identified. When combined with the microcentrifuge technique for pellet preparation, the AccuProbe test has several advantages: (i) direct identification of bacteria from blood culture broths, (ii) rapid turn-around time (30 min), (iii) simplicity of the procedure, and (iv) relative low cost.


Subtypes of social withdrawal in early childhood: sociometric status and social-cognitive differences across four years.
From a sample of 567 kindergartners observed during free play, 150 children were classified as socially withdrawn and followed over 4 years. A cluster analysis involving teacher ratings was used to identify subtypes of withdrawn children. Four clusters were identified, 3 fitting profiles found in the literature and labeled unsociable (n = 96), passive-anxious (n = 23), and active-isolate (n = 19), and 1 typically not discussed, labeled sad/depressed (n = 12). Sociometric ratings indicated that unsociable children had elevated rates of sociometric neglect, active-isolates had higher than expected levels of rejection, and sad/depressed children had elevated rates of both neglect and rejection. Subtypes also differed in social information-processing patterns, with active-isolate children displaying the least component skills. The findings that some experience more difficulty than others might account for the ambiguity in extant studies regarding whether or not social withdrawal is a risk factor in psychosocial development, because withdrawal has most often been treated as a unitary construct in the past.


CXCL1 and its receptor, CXCR2, mediate murine sickle cell vaso-occlusion during hemolytic transfusion reactions.
Hemolytic transfusion reactions (HTRs) can produce serious and potentially life-threatening complications in sickle cell disease (SCD) patients; however, the mechanisms underlying these complications remain undetermined. We established a model of alloimmune, IgG-mediated HTRs in a well-characterized humanized murine model of SCD. HTRs induced acute vaso-occlusive crisis (VOC), resulting in shortened survival of SCD mice. Acute VOC was associated with elevated circulating inflammatory chemokine levels, including striking elevation of the levels of the neutrophil chemoattractant CXCL1. Recombinant CXCL1 administration was sufficient to induce acute VOC in SCD mice, characterized by leukocyte recruitment in venules, capture of circulating red blood cells, reduction of venular flow, and shortened survival. In contrast, blockade of the CXCL1 receptor, CXCR2, prevented HTR-elicited acute VOC and prolonged survival in SCD mice. These results indicate that CXCL1 is a key inflammatory mediator of acute VOC in SCD mice. Targeted inhibition of CXCL1 and/or CXCR2 may therefore represent a new therapeutic approach for acute VOC in SCD patients.


Nitrate and glutamate sensing by plant roots.
The architecture of a root system plays a major role in determining how efficiently a plant can capture water and nutrients from the soil. Growth occurs at the root tips and the process of exploring the soil volume depends on the behaviour of large numbers of individual root tips at different orders of branching. Each root tip is equipped with a battery of sensory mechanisms that enable it to respond to a range of environmental signals, including nutrients, water potential, light, gravity and touch. We have previously identified a MADS (MCM1, agamous, deficiens and SRF) box gene (ANR1) in Arabidopsis thaliana that is involved in modulating the rate of lateral root growth in response to changes in the external NO(3)(-) supply. Transgenic plants have been generated in which a constitutively expressed ANR1 protein can be post-translationally activated by treatment with dexamethasone (DEX). When roots of these lines are treated with DEX, lateral root growth is markedly stimulated but there is no effect on primary root growth, suggesting that one or more components of the regulatory pathway that operate in conjunction with ANR1 in lateral roots may be absent in the primary root tip. We have recently observed some very specific effects of low concentrations of glutamate on root growth, resulting in significant changes in root architecture. Experimental evidence suggests that this response involves the sensing of extracellular glutamate by root tip cells. We are currently investigating the possible role of plant ionotropic glutamate receptors in this sensory mechanism.


California's minority majority and the White face of nursing.
Of the 33 million people in California, the nation's most populous state, minority groups now constitute the majority of the population. Many sources predict that by 2060, the entire country will mirror the diversity of California today. Like the rest of the country, California is experiencing a critical shortage of nurses that is predicted to increase in the coming years, and California's nursing workforce does not represent the racial and ethnic diversity of the state's population as a whole. If the nursing profession is to thrive in the coming years, educators and leaders must create a way to embrace people from diverse ethnicities and cultures. The purposes of this article are to determine whether ethnic minority groups have different success rates in California nursing programs, whether nursing programs with high percentages of diverse students have differing success rates, and to describe the institutional predictors of on-time completion rates, attrition rates, and NCLEX-RN first-time pass rates in California community colleges.


Population Genetics of Plasmodium vivax in the Peruvian Amazon.
Characterizing the parasite dynamics and population structure provides useful information to understand the dynamic of transmission and to better target control interventions. Despite considerable efforts for its control, vivax malaria remains a major health problem in Peru. In this study, we have explored the population genetics of Plasmodium vivax isolates from Iquitos, the main city in the Peruvian Amazon, and 25 neighbouring peri-urban as well as rural villages along the Iquitos-Nauta Road. From April to December 2008, 292 P. vivax isolates were collected and successfully genotyped using 14 neutral microsatellites. Analysis of the molecular data revealed a similar proportion of monoclonal and polyclonal infections in urban areas, while in rural areas monoclonal infections were predominant (p = 0.002). Multiplicity of infection was higher in urban (MOI = 1.5-2) compared to rural areas (MOI = 1) (p = 0.003). The level of genetic diversity was similar in all areas (He = 0.66-0.76, p = 0.32) though genetic differentiation between areas was substantial (PHIPT = 0.17, p<0.0001). Principal coordinate analysis showed a marked differentiation between parasites from urban and rural areas. Linkage disequilibrium was detected in all the areas ([Formula: see text] = 0.08-0.49, for all p<0.0001). Gene flow among the areas was stablished through Bayesian analysis of migration models. Recent bottleneck events were detected in 4 areas and a recent parasite expansion in one of the isolated areas. In total, 87 unique haplotypes grouped in 2 or 3 genetic clusters described a sub-structured parasite population. Our study shows a sub-structured parasite population with clonal propagation, with most of its components recently affected by bottleneck events. Iquitos city is the main source of parasite spreading for all the peripheral study areas. The routes of transmission and gene flow and the reduction of the parasite population described are important from the public health perspective as well for the formulation of future control policies.


Comparison of radiosensitivity response to acute and chronic gamma irradiation in colored wheat.
We aimed to investigate the biological responses induced by acute and chronic gamma irradiation in colored wheat seeds rich in natural antioxidants. After acute and chronic irradiation, the phenotypic effects on plant growth, germination rate, seedling height, and root length were examined, and the biochemical changes were investigated by analyzing the expression of antioxidant enzyme-related genes, antioxidant enzyme activities, and total antioxidant capacity. High dosages of chronic radiation reduced plant growth compared with the controls. Electron spin resonance measurement and 2,2-diphenyl-1-picrylhydrazyl activity analysis showed lower amount of free radicals in colored wheat seeds on chronic irradiation with low dosage of gamma rays compared to seeds subjected to acute irradiation. Expression levels of anthocyanin biosynthesis genes, antioxidant-related genes, and antioxidant enzyme activity in seeds and young leaves of seedling showed diverse effects in response to different dosages and types of gamma irradiation. This suggests that phenotype is affected by the dosage and type of gamma radiation, and the phytochemicals in colored wheat seeds involved in antioxidant activity to scavenge free radicals respond differently to irradiation types. This provides evidence that acute and chronic exposure to radiation have different effects on seeds and young leaves after germination.


Adult height and prevalence of coronary artery calcium: the National Heart, Lung, and Blood Institute Family Heart Study.
Adult height has been hypothesized to be inversely associated with coronary heart disease; however, studies have produced conflicting results. We sought to examine the relationship between adult height and the prevalence of coronary artery calcium (CAC), a direct measure of subclinical atherosclerosis and surrogate marker of coronary heart disease. We evaluated the relationship between adult height and CAC in 2703 participants from the National Heart, Lung, and Blood Institute Family Heart Study who underwent cardiac computed tomography. We used generalized estimating equations to calculate the prevalence odds ratios for the presence of CAC (CAC>0) across sex-specific quartiles of height. The mean age of the sample was 54.8 years, and 60.2% of participants were female. There was an inverse association between adult height and CAC. After adjusting for age, race, field center, waist circumference, smoking, alcohol, physical activity, systolic blood pressure, antihypertensive medications, diabetes mellitus, diabetic medications, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, lipid-lowering medications, and income, individuals in the tallest quartile had 30% lower odds of having prevalent CAC. The odds ratios (95% confidence intervals) for the presence of CAC across consecutive sex-specific quartiles of height were 1.0 (reference), 1.15 (0.86-1.53), 0.95 (0.73-1.22), and 0.70 (0.53-0.93), and P for trend<0.01. There was no evidence of effect modification for the relationship between adult height and CAC by age or socioeconomic status. The results of our study suggest an inverse, independent association between adult height and CAC.


Echocardiographic Assessment of Right Ventricular Afterload in Preterm Infants: Maturational Patterns of Pulmonary Artery Acceleration Time Over the First Year of Age and Implications for Pulmonary Hypertension.
Assessment of pulmonary hemodynamics is critical in the diagnosis and management of cardiopulmonary disease of premature infants, but reliable noninvasive indices of pulmonary hemodynamics in preterm infants are lacking. Because pulmonary artery acceleration time (PAAT) is a validated noninvasive method to assess right ventricular (RV) afterload in infants and children, the aim of this study was to investigate the maturational changes of PAAT measures in preterm infants over the first year of age and to discern the impact of typical cardiopulmonary abnormalities on these measures. In a prospective multicenter study of 239 preterm infants (<29 weeks at birth), PAAT was assessed at days 1, 2, and 5 to 7, at 32 and 36 weeks' postmenstrual age, and at 1-year corrected age. To account for heart rate variability, PAAT was adjusted for RV ejection time. Premature infants who developed bronchopulmonary dysplasia or had echocardiographic findings of pulmonary hypertension were analyzed separately. Intra- and interobserver reproducibility analysis was performed. PAAT was feasible in 95% of the image acquisitions, and there was high intra- and interobserver agreement (intraclass correlation coefficients > 0.9 and coefficients of variation < 6%). In uncomplicated preterm infants (n = 103 [48%]) PAAT and PAAT adjusted for RV ejection time increased longitudinally from birth to 1-year corrected age (P < .001) and were linearly associated with gestational age at birth (r = 0.81 and r = 0.82, P < .001) and increasing postnatal weight and postnatal age (r > 0.81, P < .001). PAAT measures were significantly reduced (P < .001) in infants with bronchopulmonary dysplasia and/or pulmonary hypertension (n = 119 [51%]) beyond 1 week of age. PAAT measures increase in preterm infants from birth to 1-year corrected age, reflective of the physiologic postnatal drop in RV afterload. Bronchopulmonary dysplasia and pulmonary hypertension have a negative impact on PAAT measures. By demonstrating excellent reliability and establishing reference patterns of PAAT in preterm infants, this study suggests that PAAT and PAAT adjusted for RV ejection time can be used as complementary parameters to assess physiologic and pathologic changes in pulmonary hemodynamics in neonates.


Solid organ transplant-associated lymphocytic choriomeningitis, United States, 2011.
Three clusters of organ transplant-associated lymphocytic choriomeningitis virus (LCMV) transmissions have been identified in the United States; 9 of 10 recipients died. In February 2011, we identified a fourth cluster of organ transplant-associated LCMV infections. Diabetic ketoacidosis developed in the organ donor in December 2010; she died with generalized brain edema after a short hospitalization. Both kidneys, liver, and lung were transplanted to 4 recipients; in all 4, severe posttransplant illness developed; 2 recipients died. Through multiple diagnostic methods, we identified LCMV infection in all persons, including in at least 1 sample from the donor and 4 recipients by reverse transcription PCR, and sequences of a 396-bp fragment of the large segment of the virus from all 5 persons were identical. In this cluster, all recipients developed severe illness, but 2 survived. LCMV infection should be considered as a possible cause of severe posttransplant illness.


A randomized controlled evaluation study of the effects of a one-day advanced rider training course.
Motorcyclists have a relative high risk of crash involvement. As a consequence there is an on-going search for safety measures to improve road safety for motorcyclists. One popular measure is motorcycle training. Although intuitively sound, there are only few thorough studies on rider training courses and they do not always show a positive safety effect. The aim of this study was to assess the effects of the advanced rider training course 'Risk'. Through random assignment motorcyclists (N=222) were assigned to an experimental and control condition. At pre- and post-test, participants completed a questionnaire and their riding behaviour was assessed in an on-road ride. Furthermore, a selection of participants took a hazard perception test at post-test. Participants in the experimental condition (n=137) followed the advanced training course 'Risk' between pre- and post-test. s indicated that trained participants were rated higher on safe riding than the control group. A positive effect was also found for riding behaviour, i.e., speed and position on the road if it needed to be adapted to increase visibility and in reaction to potential hazard. The training did not affect riders' assessment of their own riding behaviour. Overall the trained riders performed better on the hazard perception test. This study is a step forward to demonstrate that motorcyclists' traffic behaviour can be positively influenced by the right training course. Crucial for this training course is that it did not lead to overconfidence, while it quantifiably improved traffic behaviour.


Efficacy of progesterone for moderate to severe traumatic brain injury: a meta-analysis of randomized clinical trials.
Progesterone has been shown to have neuroprotective effects in multiple animal models of brain injury, whereas the efficacy and safety in patients with traumatic brain injury (TBI) remains contentious. Here, a total of seven randomized controlled trials (RCTs) with 2492 participants were included to perform this meta-analysis. Compared with placebo, there was no significant decrease to be found in the rate of death or vegetative state for patients with acute TBI (RR = 0.88, 95%CI = 0.70, 1.09, p = 0.24). Furthermore, progesterone was not associated with good recovery in comparison with placebo (RR = 1.00, 95%CI = 0.88, 1.14, p = 0.95). Together, our study suggested that progesterone did not improve outcomes over placebo in the treatment of acute TBI.


Reduced expression of Kir6.2/SUR2A subunits explains KATP deficiency in K+-depleted rats.
We investigated on the mechanism responsible for the reduced ATP-sensitive K(+)(K(ATP)) channel activity recorded from skeletal muscle of K(+)-depleted rats. Patch-clamp and gene expression measurements of K(ATP) channel subunits were performed. A down-regulation of the K(ATP) channel subunits Kir6.2(-70%) and SUR2A(-46%) in skeletal muscles of K(+)-depleted rats but no changes in the expression of Kir6.1, SUR1 and SUR2B subunits were observed. A reduced K(ATP) channel currents of -69.5% in K(+)-depleted rats was observed. The Kir6.2/SUR2A-B agonist cromakalim showed similar potency in activating the K(ATP) channels of normokalaemic and K(+)-depleted rats but reduced efficacy in K(+)-depleted rats. The Kir6.2/SUR1-2B agonist diazoxide activated K(ATP) channels in normokalaemic and K(+)-depleted rats with equal potency and efficacy. The down-regulation of the Kir6.2 explains the reduced K(ATP) channel activity in K(+)-depleted rats. The lower expression of SUR2A explains the reduced efficacy of cromakalim; preserved SUR1 expression accounts for the efficacy of diazoxide. Kir6.2/SUR2A deficiency is associated with impaired muscle function in K(+)-depleted rats and in hypoPP.


Studies of the epidemiology of bulimia nervosa.
Research on the epidemiology of bulimia nervosa has focused largely on the prevalence of the disorder. As methods have improved, consensus has increased regarding the prevalence rate among adolescent and young adult women--about 1%. However, the accuracy of this figure and its clinical significance must be questioned. In this synthesis of the epidemiological work to date, the authors review the literature from a clinical and research perspective. They recommend a shift in emphasis away from studies of the distribution of the disorder toward studies of the determinants of the whole spectrum of the disturbance that exists in the community.


Laparoscopic appendectomy versus open appendectomy in pregnancy: a population-based analysis of maternal outcome.
Laparoscopic appendectomy (LA) is the standard treatment of acute appendicitis for the general population; however, there is still some doubt regarding its safety for pregnant patients. Therefore, the purpose of this study is to investigate and compare the maternal outcome of pregnant patients with acute appendicitis following either an open appendectomy (OA) or LA from a population-based database. This study is based on the National Health Insurance Research Database. Patients with both ICD-9-CM codes for appendicitis (540.9, 540.0, and 540.1) and pregnancy (V22) in the same admission were considered to have acute appendicitis during pregnancy. These patients were divided into three groups according to the type of treatment: LA, OA, and non-operative treatment. Outcome measures that were compared between the groups included maternal complications such as preterm labor, abortion, and the need of cesarean section. Besides, the differences of medical expenditure and length of hospital stay between the groups were also analyzed. From 2005 to 2010, a total of 859 pregnant women who had acute appendicitis were identified. They had increased risks for preterm labor, abortion, and increased requirement of cesarean section compared to the control group (i.e., those without acute appendicitis). Among the three groups, the non-operated group has the highest risk of preterm labor. Patients who underwent LA did not have any increased risk of maternal complications compared to the OA group. Furthermore, LA patients had shorter hospital stay than OA. Compared to non-operative treatment, appendectomy is the preferred treatment for pregnant patients who have acute appendicitis. LA can be performed safely in pregnant patients without bringing additional maternal complications compared to OA.


Soil incorporation of logging residue affects fine-root and mycorrhizal root-tip dynamics of young loblolly pine clones.
Loblolly pine (Pinus taeda L.) plantations cover a large geographic area of the southeastern USA and supply a large proportion of the nation's wood products. Research on management strategies designed to maximize wood production while also optimizing nutrient use efficiency and soil C sequestration is needed. We used minirhizotrons to quantify the effects of incorporating logging residues into soil on fine-root standing crop, production and mortality, and mycorrhizal root tips in young loblolly pine clones of contrasting ideotypes. Clone 93 is known to allocate more C to stem growth, while clone 32 allocates less C to stems and more to leaves. The relative allocation by these clones to support fine-root turnover is unknown. Clone 32 exhibited 37% more fine-root mortality than clone 93, which was mainly the result of a greater standing crop of fine roots. Fine-root standing crop in plots amended with logging residue was initially higher than control plots, but 2.5 years after planting, standing crop in control plots had exceeded that in mulched plots. Production of mycorrhizal root tips, on the other hand, was initially higher in control than mulched plots, but during the last 9 months of the study, mycorrhizal tip production was greater in mulched than control plots, especially for clone 93. As expected, turnover rate of fine roots was greater in surface soil (0-25 cm) compared with deeper (25-50 cm) soil and for small roots (< 0.4 mm diameter) compared with larger fine roots (0.4-2.0 mm diameter). Rates of fine-root turnover were similar in both clones. Organic matter additions reduced survivorship of individual roots and increased turnover rates of fine-root populations. Results indicate that management decisions should be tailored to fit the growth and allocation patterns of available clones.


The role of plant-soil feedbacks in driving native-species recovery.
The impacts of exotic plants on soil nutrient cycling are often hypothesized to reinforce their dominance, but this mechanism is rarely tested, especially in relation to other ecological factors. In this manuscript we evaluate the influence of biogeochemically mediated plant-soil feedbacks on native shrub recovery in an invaded island ecosystem. The introduction of exotic grasses and grazing to Santa Cruz Island, California, USA, converted native shrublands (dominated by Artemisia californica and Eriogonum arborescens) into exotic-dominated grasslands (dominated by Avena barbata) over a century ago, altering nutrient-cycling regimes. To test the hypothesis that exotic grass impacts on soils alter reestablishment of native plants, we implemented a field-based soil transplant experiment in three years that varied widely in rainfall. Our results showed that growth of Avena and Artemisia seedlings was greater on soils influenced by their heterospecific competitor. Theory suggests that the resulting plant-soil feedback should facilitate the recovery of Artemisia in grasslands, although four years of monitoring showed no such recovery, despite ample seed rain. By contrast, we found that species effects on soils lead to weak to negligible feedbacks for Eriogonum arborescens, yet this shrub readily colonized the grasslands. Thus, plant-soil feedbacks quantified under natural climate and competitive conditions did not match native-plant recovery patterns. We also found that feedbacks changed with climate and competition regimes, and that these latter factors generally had stronger effects on seedling growth than species effects on soils. We conclude that even when plant-soil feedbacks influence the balance between native and exotic species, their influence may be small relative to other ecological processes.


Meta-analysis of the effect of the acid-ash hypothesis of osteoporosis on calcium balance.
The acid-ash hypothesis posits that protein and grain foods, with a low potassium intake, produce a diet acid load, net acid excretion (NAE), increased urine calcium, and release of calcium from the skeleton, leading to osteoporosis. The objectives of this meta-analysis were to assess the effect of changes in NAE, by manipulation of healthy adult subjects' acid-base intakes, on urine calcium, calcium balance, and a marker of bone metabolism, N-telopeptides. This meta-analysis was limited to studies that used superior methodological quality for the study of calcium metabolism. We systematically searched the literature and included studies if subjects were randomized to the interventions and followed the recommendations of the Institute of Medicine's Panel on Calcium and Related Nutrients for calcium studies. Five of 16 studies met the inclusion criteria. The studies altered the amount and/or type of protein. Despite a significant linear relationship between an increase in NAE and urinary calcium (p < 0.0001), there was no relationship between a change of NAE and a change of calcium balance (p = 0.38; power = 94%). There was no relationship between a change of NAE and a change in the marker of bone metabolism, N-telopeptides (p = 0.95). In conclusion, this meta-analysis does not support the concept that the calciuria associated with higher NAE reflects a net loss of whole body calcium. There is no evidence from superior quality balance studies that increasing the diet acid load promotes skeletal bone mineral loss or osteoporosis. Changes of urine calcium do not accurately represent calcium balance. Promotion of the "alkaline diet" to prevent calcium loss is not justified.


Inhibition of 5-HT cell firing in the DRN by non-selective 5-HT reuptake inhibitors: studies on the role of 5-HT1A autoreceptors and noradrenergic mechanisms.
Improved clinical antidepressant efficacy may result if the acute inhibition of 5-HT cell firing induced by antidepressants is prevented. Here we examined whether inhibition of 5-HT cell firing by non-selective 5-HT uptake inhibiting antidepressant drugs is reversed by a selective 5-HT1A receptor antagonist. In addition, we examined whether concomitant blockade of NA uptake offsets the inhibition of 5-HT cell firing resulting from 5-HT uptake blockade. Antidepressants which block 5-HT uptake (paroxetine, clomipramine, amitriptyline, venlafaxine), all caused dose-dependent and complete inhibition of 5-HT cell firing. Desipramine, a selective NA uptake blocker, caused a slight reduction in firing. The selective 5-HT1A receptor antagonist, WAY 100635, reversed the inhibition of 5-HT cell firing induced by clomipramine, amitriptyline, venlafaxine, and paroxetine, but not that induced by the alpha 1 adrenoceptor antagonist, prazosin. Desipramine, at a dose which increased extracellular NA in the DRN, reversed the effect of prazosin but did not alter the ability of paroxetine to inhibit 5-HT cell firing. Our data indicate that antidepressant drugs with 5-HT uptake blocking properties inhibit 5-HT cell firing via activation of 5-HT1A autoreceptors, and do so irrespective of their effects on NA uptake. These data are discussed in relation to the application of 5-HT1A receptor antagonists to enhance the clinical efficacy of antidepressant drugs.


Evaluation of Adaptive Feedback in a Smartphone-Based Game on Health Care Providers' Learning Gain: Randomized Controlled Trial.
Although smartphone-based emergency care training is more affordable than traditional avenues of training, it is still in its infancy, remains poorly implemented, and its current implementation modes tend to be invariant to the evolving learning needs of the intended users. In resource-limited settings, the use of such platforms coupled with gamified approaches remains largely unexplored, despite the lack of traditional training opportunities, and high mortality rates in these settings. The primary aim of this randomized experiment is to determine the effectiveness of offering adaptive versus standard feedback, on the learning gains of clinicians, through the use of a smartphone-based game that assessed their management of a simulated medical emergency. A secondary aim is to examine the effects of learner characteristics and learning spacing with repeated use of the game on the secondary outcome of individualized normalized learning gain. The experiment is aimed at clinicians who provide bedside neonatal care in low-income settings. Data were captured through an Android app installed on the study participants' personal phones. The intervention, which was based on successful attempts at a learning task, included adaptive feedback provided within the app to the experimental arm, whereas the control arm received standardized feedback. The primary end point was completion of the second learning session. Of the 572 participants enrolled between February 2019 and July 2019, 247 (43.2%) reached the primary end point. The primary outcome was standardized relative change in learning gains between the study arms as measured by the Morris G effect size. The secondary outcomes were the participants individualized normalized learning gains. The effect of adaptive feedback on care providers' learning gain was found to be g=0.09 (95% CI -0.31 to 0.46; P=.47). In exploratory analysis, using normalized learning gains, when subject-treatment interaction and differential time effect was controlled for, this effect increased significantly to 0.644 (95% CI 0.35 to 0.94; P<.001) with immediate repetition, which is a moderate learning effect, but reduced significantly by 0.28 after a week. The overall learning change from the app use in both arms was large and may have obscured a direct effect of feedback. There is a considerable learning gain between the first two rounds of learning with both forms of feedback and a small added benefit of adaptive feedback after controlling for learner differences. We suggest that linking the adaptive feedback provided to care providers to how they space their repeat learning session(s) may yield higher learning gains. Future work might explore in more depth the feedback content, in particular whether or not explanatory feedback (why answers were wrong) enhances learning more than reflective feedback (information about what the right answers are). Pan African Clinical Trial Registry (PACTR) 201901783811130; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=5836. RR2-10.2196/13034.


Physicians practicing in methadone treatment programs: who are they and what do they do?
This study examines the characteristics and roles of physicians practicing in methadone maintenance treatment programs (MTPs). Physicians and clinic directors at 172 MTPs in the United States completed surveys. MTPs were selected for study participation based on their locations (large urban, urban, or nonurban area) ownership status (for profit and non-profit), and size (patient capacity of 1-100, 101-300, and 300+). Weighted data were analyzed with descriptive and multivariate methods. RESULTS. Physicians were primarily white males aged 45 or older; 44% had 10 or more years of experience working in methadone treatment. Physicians reported spending 26% of their time completing administrative tasks. Most reported that they determine dosing levels on an individual patient basis. Average maintenance dose was 69 mg/day. Physicians' treatment practices play a major role in overall treatment, treatment retention, and outcomes. Physicians at for-profit and large urban MTPs reported spending the most time in direct patient contact.


The science of clinical practice: disease diagnosis or patient prognosis? Evidence about "what is likely to happen" should shape clinical practice.
Diagnosis is the traditional basis for decision-making in clinical practice. Evidence is often lacking about future benefits and harms of these decisions for patients diagnosed with and without disease. We propose that a model of clinical practice focused on patient prognosis and predicting the likelihood of future outcomes may be more useful. Disease diagnosis can provide crucial information for clinical decisions that influence outcome in serious acute illness. However, the central role of diagnosis in clinical practice is challenged by evidence that it does not always benefit patients and that factors other than disease are important in determining patient outcome. The concept of disease as a dichotomous 'yes' or 'no' is challenged by the frequent use of diagnostic indicators with continuous distributions, such as blood sugar, which are better understood as contributing information about the probability of a patient's future outcome. Moreover, many illnesses, such as chronic fatigue, cannot usefully be labelled from a disease-diagnosis perspective. In such cases, a prognostic model provides an alternative framework for clinical practice that extends beyond disease and diagnosis and incorporates a wide range of information to predict future patient outcomes and to guide decisions to improve them. Such information embraces non-disease factors and genetic and other biomarkers which influence outcome. Patient prognosis can provide the framework for modern clinical practice to integrate information from the expanding biological, social, and clinical database for more effective and efficient care.


Vibronic origin of long-lived coherence in an artificial molecular light harvester.
Natural and artificial light-harvesting processes have recently gained new interest. Signatures of long-lasting coherence in spectroscopic signals of biological systems have been repeatedly observed, albeit their origin is a matter of ongoing debate, as it is unclear how the loss of coherence due to interaction with the noisy environments in such systems is averted. Here we report experimental and theoretical verification of coherent exciton-vibrational (vibronic) coupling as the origin of long-lasting coherence in an artificial light harvester, a molecular J-aggregate. In this macroscopically aligned tubular system, polarization-controlled 2D spectroscopy delivers an uncongested and specific optical response as an ideal foundation for an in-depth theoretical description. We derive analytical expressions that show under which general conditions vibronic coupling leads to prolonged excited-state coherence.


MetLab: An In Silico Experimental Design, Simulation and Analysis Tool for Viral Metagenomics Studies.
Metagenomics, the sequence characterization of all genomes within a sample, is widely used as a virus discovery tool as well as a tool to study viral diversity of animals. Metagenomics can be considered to have three main steps; sample collection and preparation, sequencing and finally bioinformatics. Bioinformatic analysis of metagenomic datasets is in itself a complex process, involving few standardized methodologies, thereby hampering comparison of metagenomics studies between research groups. In this publication the new bioinformatics framework MetLab is presented, aimed at providing scientists with an integrated tool for experimental design and analysis of viral metagenomes. MetLab provides support in designing the metagenomics experiment by estimating the sequencing depth needed for the complete coverage of a species. This is achieved by applying a methodology to calculate the probability of coverage using an adaptation of Stevens' theorem. It also provides scientists with several pipelines aimed at simplifying the analysis of viral metagenomes, including; quality control, assembly and taxonomic binning. We also implement a tool for simulating metagenomics datasets from several sequencing platforms. The overall aim is to provide virologists with an easy to use tool for designing, simulating and analyzing viral metagenomes. The results presented here include a benchmark towards other existing software, with emphasis on detection of viruses as well as speed of applications. This is packaged, as comprehensive software, readily available for Linux and OSX users at https://github.com/norling/metlab.


Fever and Thrombocytopenia in a Returning Soldier.
A case of fever and thrombocytopenia in a 33-year-old Special Forces Soldier with recent deployment to the Philippines is discussed, as are differential diagnosis and initial medical management at an overseas, fixed US military medical treatment facility. The authors discuss lessons learned that are applicable for Special Operations Forces (SOF) medical providers and recommend a renewed and continued emphasis on tropical medicine and infectious disease training for SOF medical providers.


Assessment of detective quantum efficiency: intercomparison of a recently introduced international standard with prior methods.
To prospectively evaluate the recently introduced international standard method for measurement of the detective quantum efficiency (DQE) of digital radiography systems, in comparison with representative prior methods. A recently introduced international standard method (International Electrotechnical Commission [IEC] 62220-1, 2003) for DQE measurement and two previously described DQE evaluation methods were considered. In addition to an overall comparison, evaluations of the following method factors were performed: beam quality, beam-limiting devices (apertures or collimators), noise power spectrum (NPS) analysis algorithms and parameters (area, region of interest size, background detrending), and modulation transfer function (MTF) test devices and methods. Overall, at low to middle frequencies, the IEC method yielded DQE estimates that were 3.3% and 6.5% lower than the values yielded by the two previous methods. Averaged over the frequency range of 1.5-2.5 mm(-1), the DQE estimate derived by using the IEC method was 7.1% lower and 12.4% higher than the estimates derived by using the other two methods. Results obtained with the two previous DQE evaluation methods agreed well (within 2.0%) in the low- to middle-frequency range but diverged by up to 10% at higher frequencies. When the DQE method factors were evaluated separately, the largest percentage deviations in DQE were associated with (in order of decreasing influence) the MTF analysis method ( approximately 11%), the beam limitation (about 7%-10%), the beam quality ( approximately 9%), and the NPS analysis method ( approximately 3%). Comparison of DQE estimates obtained by using the recently introduced international standard technique with those obtained by using prior methods revealed that the overall measurement method can affect the DQE estimate by as much as 12%. Findings further suggest that both beam limitation achieved by means of internal collimation (rather than external apertures) and use of a radio-opaque edge MTF device yield a more accurate estimation of the DQE.


A faint type of supernova from a white dwarf with a helium-rich companion.
Supernovae are thought to arise from two different physical processes. The cores of massive, short-lived stars undergo gravitational core collapse and typically eject a few solar masses during their explosion. These are thought to appear as type Ib/c and type II supernovae, and are associated with young stellar populations. In contrast, the thermonuclear detonation of a carbon-oxygen white dwarf, whose mass approaches the Chandrasekhar limit, is thought to produce type Ia supernovae. Such supernovae are observed in both young and old stellar environments. Here we report a faint type Ib supernova, SN 2005E, in the halo of the nearby isolated galaxy, NGC 1032. The 'old' environment near the supernova location, and the very low derived ejected mass ( approximately 0.3 solar masses), argue strongly against a core-collapse origin. Spectroscopic observations and analysis reveal high ejecta velocities, dominated by helium-burning products, probably excluding this as a subluminous or a regular type Ia supernova. We conclude that it arises from a low-mass, old progenitor, likely to have been a helium-accreting white dwarf in a binary. The ejecta contain more calcium than observed in other types of supernovae and probably large amounts of radioactive (44)Ti.


Ret proto-oncogene mutations in apparently sporadic Turkish medullary thyroid carcinoma patients: Turkmen study.
Medullary thyroid carcinoma (MTC) frequently occurs in a sporadic form, but a substantial number of cases are hereditary and appear as part of the multiple endocrine neoplasia type 2 (MEN2) syndromes. Germline mutations in ret proto-oncogene have been shown to be the underlying cause of MEN2 syndromes. We carried out a multi-center study that aimed to perform mutational analysis of so called sporadic MTC patients. Fifty-six MTC patients verified by histopathologic examination were subjected to genetic analysis. Exon 10, 11, 13, 14, 15 and 16 of the ret gene were analyzed by DNA sequencing and restriction enzyme digestion method. Among 56 apparently sporadic MTC patients, we identified 6 (10.7%) ret germline mutation carriers. Three individuals carried mutations at codon 634 in exon 11, one at codon 618 in exon 10, and two at codon 804 in exon 14. Identification of the predisposition gene mutation has allowed DNA-based strategy for direct mutation detection in patients with apparently sporadic MTCs. A substantial number of patients with apparently sporadic MTC carried germline mutations and 50% of their first degree relatives are expected to have or to develop MTC and/or other endocrine tumors. These results indicate the importance of careful genetic surveillance of any patient with apparently sporadic MTCs.


Thermal desorption of hydrogen from carbon nanosheets.
Carbon nanosheets are a unique nanostructure that, at their thinnest configuration, approach a single freestanding graphene sheet. Temperature desorption spectroscopy (TDS) has shown that the hydrogen adsorption and incorporation during growth of the nanosheets by radio frequency plasma-enhanced chemical vapor deposition are significant. A numerical peak fitting to the desorption spectra (300-1273 K) via the Polanyi-Wigner equation showed that desorption followed a second order process, presumably by the Langmuir-Hinshelwood mechanism. Six peaks provide the best fit to the TDS spectra. Surface desorption activation energies were determined to be 0.59, 0.63, and 0.65 eV for the external graphite surface layers and 0.85, 1.15, and 1.73 eV for desorption and diffusion from the bulk. In contrast to TDS data from previously studied a-C:H films [Schenk et al. J. Appl. Phys. 77, 2462 (1995)], a greater amount of hydrogen bound as sp(2) hybridized carbon was observed. A previous x-ray diffraction study of these films has shown a significant graphitic character with a crystallite dimension of L(a)=10.7 nm. This result is consistent with experimental results by Raman spectroscopy that show as-grown carbon nanosheets to be crystalline as commercial graphite with a crystallite size of L(a)=11 nm. Following TDS, Raman data indicate that the average crystallite increased in size to L(a)=15 nm.


Evolution of an adenocarcinoma in response to selection by targeted kinase inhibitors.
Adenocarcinomas of the tongue are rare and represent the minority (20 to 25%) of salivary gland tumors affecting the tongue. We investigated the utility of massively parallel sequencing to characterize an adenocarcinoma of the tongue, before and after treatment. In the pre-treatment tumor we identified 7,629 genes within regions of copy number gain. There were 1,078 genes that exhibited increased expression relative to the blood and unrelated tumors and four genes contained somatic protein-coding mutations. Our analysis suggested the tumor cells were driven by the RET oncogene. Genes whose protein products are targeted by the RET inhibitors sunitinib and sorafenib correlated with being amplified and or highly expressed. Consistent with our observations, administration of sunitinib was associated with stable disease lasting 4 months, after which the lung lesions began to grow. Administration of sorafenib and sulindac provided disease stabilization for an additional 3 months after which the cancer progressed and new lesions appeared. A recurring metastasis possessed 7,288 genes within copy number amplicons, 385 genes exhibiting increased expression relative to other tumors and 9 new somatic protein coding mutations. The observed mutations and amplifications were consistent with therapeutic resistance arising through activation of the MAPK and AKT pathways. We conclude that complete genomic characterization of a rare tumor has the potential to aid in clinical decision making and identifying therapeutic approaches where no established treatment protocols exist. These results also provide direct in vivo genomic evidence for mutational evolution within a tumor under drug selection and potential mechanisms of drug resistance accrual.


Molecular modeling of surfactant covered oil-water interfaces: Dynamics, microstructure, and barrier for mass transport.
Mass transport across surfactant-covered oil-water interfaces of microemulsions plays an important role in numerous applications. In the current work, we use coarse-grained molecular dynamics simulations to investigate model systems containing flat hexadecane-water interfaces covered by monolayers of nonionic surfactants of various lengths. Several properties of the surfactant monolayers relevant to the mass transport are considered, including the monolayer microstructure, dynamics, and a free energy barrier to the solute transport. It is observed that the dominant contribution of a surfactant monolayer to the free energy barrier is a steric repulsion caused by a local density increase inside the monolayer. The local densities, and hence the free energy barriers, are larger for monolayers composed of longer surfactants. Since it is likely that the solute transport mechanism involves a sequence of jumps between short-lived pores within a monolayer, we perform a detailed analysis of structure, size, and lifetime of these pores. We demonstrate that the pore statistics is consistent with predictions of percolation theory and apply this theory to identify the characteristic length scale of the monolayer microstructure. The obtained pore structures are sensitive to minute changes of surfactant configurations occurring on the picosecond time scale. To reduce this sensitivity, the pores are averaged over short time intervals. The optimal duration of these time intervals is estimated from analysis of dynamics of pores with diameters comparable to or exceeding the characteristic percolation length scale. The developed approach allows one to filter out transient events of the pore dynamics and to focus on events leading to substantial changes of the monolayer microstructure.


Microcrack accumulation at different intervals during fatigue testing of compact bone.
Fatigue damage in bone occurs in the form of microcracks. This microdamage contributes to the formation of stress fractures and acts as a stimulus for bone remodelling. A technique has been developed, which allows microcrack growth to be monitored during the course of a fatigue test by the application of a series of fluorescent chelating agents. Specimens were taken from bovine tibiae and fatigue tested in cyclic compression at a stress range of 80MPa. The specimens were stained before testing with alizarin and up to three other chelating agents were applied during testing to label microcracks formed at different times. Microcracks initiated in interstitial bone in the early part of a specimen's life. Further accumulation of microcracks is then suppressed until the period late in the specimen's life. Microcracks were found to be longer in the longitudinal than in the transverse direction. Only a small proportion of cracks are actively propagating; these are longer than non-propagating cracks. These results support the concept of a microstructural barrier effect existing in bone, whereby cracks initiate easily but slow down or stop at barriers such as cement lines.


Examining the support-supply and bud-packing hypotheses for the increase in toothed leaf margins in northern deciduous floras.
The proportion of woody dicots with toothed leaves increases toward colder regions, a relationship used to reconstruct past mean annual temperatures. Recent hypotheses explaining this relationship are that (1) leaves in colder regions are thinner, requiring thick veins for support and water supply, with the resulting craspedodromous venation leading to marginal teeth (support-supply hypothesis) or that (2) teeth are associated with the packing of leaf primordia in winter buds (bud-packing hypothesis). We addressed these hypotheses by examining leaf thickness, number of primordia in buds, growing season length (mean annual temperature, MAT), and other traits in 151 deciduous woody species using georeferenced occurrences and a Bayesian model controlling for phylogeny. We excluded evergreen species because longer leaf life spans correlate with higher leaf mass per area, precluding the detection of independent effects of leaf thickness on leaf-margin type. The best model predicted toothed leaves with 94% accuracy, with growing season length the strongest predictor. Neither leaf thickness nor number of leaves preformed in buds significantly influenced margin type, rejecting the support-supply and bud-packing hypotheses. A direct selective benefit of leaf teeth via a carbon gain early in the spring as proposed by Royer and Wilf (2006) would match the strong correlation between toothed species occurrence and short growing season found here using Bayesian hierarchical models. Efforts should be directed to physiological work quantifying seasonal photosynthate production in toothed and nontoothed leaves.


Stress, Burnout and Coping among Emergency Physicians at a Major Hospital in Kingston, Jamaica.
The study examined the prevalence of stress, burnout, and coping, and the relationship between these variables among emergency physicians at a teaching hospital in Kingston, Jamaica. Thirty out of 41 physicians in the Emergency Department completed the Maslach Burnout Inventory, Perceived Stress Scale, Ways of Coping Questionnaire, and a background questionnaire. Descriptive statistical analyses were conducted. Fifty per cent of study participants scored highly on emotional exhaustion; the scores of 53.3% also indicated that they were highly stressed. Stress correlated significantly with the emotional exhaustion and depersonalization components of burnout. Depersonalization was significantly correlated with two coping strategies: escape-avoidance and accepting responsibility; emotional exhaustion was also significantly correlated with escape-avoidance. Emergency physicians at the hospital scored high on stress and components of burnout. Interventions aimed at reducing the occupational contributors to stress and improving levels of coping will reduce the risk of burnout and enhance psychological well-being among emergency physicians.


Enterotoxic effects of Aeromonas sobria haemolysin in a rat jejunal perfusion system identified by specific neutralization with a monoclonal antibody.
Investigations into the pathogenesis of Aeromonas diarrhoea have demonstrated that several different cell-free products of motile aeromonads show enterotoxic activity in suckling mouse, rat, and rabbit assay systems. The relative contributions made by separate cytotoxic and cytotonic activities in the mixture produced by in vitro culture remains unresolved. Using a modified rat jejunal perfusion assay, we have studied the effects of A. sobria culture filtrates containing defined levels of haemolytic and cytotoxic activity and immunoreactivity for anti-cholera toxin. This material induced net water, potassium, and sodium loss with a rapid onset (less than 5 min) that was readily differentiated from the effects of purified cholera toxin (greater than 15 min). In filtrates containing up to 128 haemolytic and cytotoxic units of activity, the enterotoxic activity was neutralized by an anti-haemolysin/cytotoxin monoclonal antibody. No specific histological changes could be found in preparations perfused with enterotoxic material for up to 65 min. These findings indicate that the cytotoxic/haemolytic component of A. sobria culture filtrate is the dominant enterotoxic activity.


Drugs associated with teratogenic mechanisms. Part I: dispensing rates among pregnant women in the Netherlands, 1998-2009.
What are the dispensing rates of drugs suspected to be associated with teratogenic mechanisms among pregnant Dutch women? In a substantial proportion of pregnancies in our study population at least one drug associated with a teratogenic mechanism was dispensed in the first trimester of pregnancy. The main teratogenic mechanisms of medical drugs that may affect fetal development in the first trimester of pregnancy have been described previously. However, information on the dispensing rate of such drugs among women at all stages of pregnancy is lacking. To determine how often medications suspected to be associated with a teratogenic mechanism are used by pregnant women, we studied 32 016 pregnancies included in the IADB.nl database between 1998 and 2009. We estimated dispensing rates of medical drugs suspected to be associated with teratogenic mechanisms in our study population. The IADB.nl database includes all pharmacy dispensings for an estimated population of 220 000 in 1994-1998 and c.500 000 since 1999. In addition, trends in first trimester dispensing rates over time and patterns of receiving multiple drugs associated with teratogenic mechanisms were evaluated. In addition, we determined the number of pregnancies in which multiple prescription drugs from one or more teratogenic categories were dispensed in the first trimester, and we evaluated the numbers of different medications dispensed that could be grouped within a specific teratogenic mechanism. In 175 per 1000 pregnancies [95% confidence interval (CI), 171-179] at least one drug associated with a teratogenic mechanism was dispensed in the first trimester. The total dispensing rate was 236 per 1000 pregnancies (95% CI 232-241) in the 3 months before pregnancy and an increasing trend was seen in the second [214 per 1000 (95% CI 209-218)] and third [327 per 1000 (95% CI 322-332)] trimesters. The first trimester dispensing rates increased between 1998 and 2009 for selective serotonin-reuptake inhibitors (P < 0.001) and serotonin receptor agonists/antagonists (P < 0.001). In 71.8% of pregnancies in which drugs associated with teratogenic mechanisms were dispensed in the first trimester, women received drugs related to only one mechanism. Of the pregnancies in which drugs from multiple teratogenic categories were dispensed in the first trimester, 1148 (72.6%) women received drugs from 2 categories, 317 (20.0%) from three categories, 88 (5.6%) from 4 categories, 28 (1.8%) from 5 categories and 1 from 6 categories. Several women received multiple prescription medications grouped within a single teratogenic mechanism in the first trimester, ranging between 13.3% for cyclo-oxygenase inhibitors and 41.8% for serotonin receptor agonists/antagonists. We used a dispensing database, therefore actual use of the medication prescribed is unknown and non-compliance could have led to overestimation of exposure prevalences. Owing to the uncertainties concerning the safety of medication use during pregnancy, the results of this study stress the need for cautious prescription of medication associated with teratogenic mechanisms to women of reproductive age. This is further supported by our finding that women received multiple prescription medications grouped within a single teratogenic mechanism in the first trimester, which would theoretically increase strongly the risk of birth defects. Marleen van Gelder was supported by the Netherlands Organisation for Scientific Research/NWO (grant no. 021.001.008). No competing interests are declared. N/A.


Long-Term Risk of Myocardial Infarction Compared to Recurrent Stroke After Transient Ischemic Attack and Ischemic Stroke: Systematic Review and Meta-Analysis.
Uncertainties remain about the current risk of myocardial infarction (MI) after ischemic stroke or transient ischemic attack. We undertook a systematic review to estimate the long-term risk of MI, compared to recurrent stroke, with temporal trends in ischemic stroke/transient ischemic attack patients. Annual risks and 95% confidence intervals (95% CI) of MI and recurrent stroke were estimated using random-effect meta-analyses. We calculated incidence ratios of MI/recurrent stroke, for fatal and nonfatal events, using similar analyses. Rate ratios for MI in patients with potential risk factors compared to those without were calculated using Poisson regression.A total of 58 studies (131 299 patients) with a mean (range) follow-up of 3.5 (1.0-10.0) years were included. The risk of MI was 1.67%/y (95% CI 1.36-1.98, Phet<0.001 for heterogeneity) and decreased over time (Pint=0.021); 96% of the heterogeneity between studies was explained by study design, study period, follow-up duration, mean age, proportion of patients on antithrombotic therapy, and incident versus combined ischemic stroke/transient ischemic attack. The risk of recurrent stroke was 4.26%/y (95% CI 3.43-5.09, Phet<0.001), with no change over time (Pint=0.63). The risk of fatal MI was half the risk of recurrent strokes ending in fatality (incidence ratio=0.51, 95% CI 0.14-0.89, Phet=0.58). The risk of nonfatal MI was 75% smaller than the risk of recurrent nonfatal stroke (incidence ratio=0.25, 95%CI 0.02-0.50, Phet=0.68). Male sex, hypertension, coronary and peripheral artery diseases were associated with a doubled risk of MI. After ischemic stroke/transient ischemic attack, the risk of MI is currently <2%/y, and recurrent stroke is a more common cause of death than MI.


A new family of polymorphic genes in Saccharomyces cerevisiae: alpha-galactosidase genes MEL1-MEL7.
Using genetic hybridization analysis we identified seven polymorphic genes for the fermentation of melibiose in different Mel+ strains of Saccharomyces cerevisiae. Four laboratory strains (1453-3A, 303-49, N2, C.B.11) contained only the MEL1 gene and a wild strain (VKM Y-1830) had only the MEL2 gene. Another wild strain (CBS 4411) contained five genes: MEL3, MEL4, MEL5, MEL6 and MEL7. MEL3-MEL7 were isolated and identified by backcrosses with Mel- parents (X2180-1A, S288C). A cloned MEL1 gene was used as a probe to investigate the physical structure and chromosomal location of the MEL gene family and to check the segregation of MEL genes from CBS 4411 in six complete tetrads. Restriction and Southern hybridization analyses showed that all seven genes are physically very similar. By electrokaryotyping we found that all seven genes are located on different chromosomes: MEL1 on chromosome II as shown previously by Voll-rath et al. (1988), MEL2 on VII, MEL3 on XVI, MEL4 on XI, MEL5 on IV. MEL6 on XIII, and MEL7 on VI. Molecular analysis of the segregation of MEL genes from strain CBS 4411 gave results identical to those from the genetic analyses. The homology in the physical structure of this MEL gene family suggests that the MEL loci have evolved by transposition of an ancestral gene to specific locations within the genome.


Low Neuroactive Steroids Identifies a Biological Subtype of Depression in Adults with Human Immunodeficiency Virus on Suppressive Antiretroviral Therapy.
The prevalence and mortality risk of depression in people with human immunodeficiency virus (HIV) infection receiving antiretroviral therapy (ART) is higher than in the general population, yet biomarkers for therapeutic targeting are unknown. In the current study, we aimed to identify plasma metabolites associated with depressive symptoms in people with HIV receiving ART. This is a prospective study of ART-treated HIV-infected adults with or without depressive symptoms assessed using longitudinal Beck Depression Inventory scores. Plasma metabolite profiling was performed in 2 independent cohorts (total n = 99) using liquid and gas chromatography and tandem mass spectrometry. Participants with depressive symptoms had lower neuroactive steroids (dehydroepiandrosterone sulfate [DHEA-S], androstenediols, and pregnenolone sulfate) compared with those without depressive symptoms. The cortisol/DHEA-S ratio, an indicator of hypothalamic-pituitary-adrenal axis imbalance, was associated with depressive symptoms (P < .01) because of low DHEA-S levels, whereas cortisol was similar between groups. The odds of having depressive symptoms increased with higher cortisol/DHEA-S ratios (adjusted odds ratio, 2.5 per 1-unit increase in z score; 95% confidence interval, 1.3-4.7), independent of age and sex. The kynurenine-to-tryptophan ratio showed no significant associations. These findings suggest that altered neuroactive steroid metabolism may contribute to the pathophysiological mechanisms of depression in ART-treated HIV-infected adults, representing a potential biological pathway for therapeutic targeting.