Hepatobiliary MRI as novel selection criteria in liver transplantation for hepatocellular carcinoma.
Hepatobiliary magnetic resonance imaging (MRI) provides additional information beyond the size and number of tumours, and may have prognostic implications. We examined whether pretransplant radiological features on MRI could be used to stratify the risk of tumour recurrence after liver transplantation (LT) for hepatocellular carcinoma (HCC). A total of 100 patients who had received a liver transplant and who had undergone preoperative gadoxetic acid-enhanced MRI, including the hepatobiliary phase (HBP), were reviewed for tumour size, number, and morphological type (e.g. nodular, nodular with perinodular extension, or confluent multinodular), satellite nodules, non-smooth tumour margins, peritumoural enhancement in arterial phase, peritumoural hypointensity on HBP, and apparent diffusion coefficients. The primary endpoint was time to recurrence. In a multivariable adjusted model, the presence of satellite nodules [hazard ratio (HR) 3.07; 95% confidence interval (CI) 1.14-8.24] and peritumoural hypointensity on HBP (HR 4.53; 95% CI 1.52-13.4) were identified as independent factors associated with tumour recurrence. Having either of these radiological findings was associated with a higher tumour recurrence rate (72.5% vs. 15.4% at three years, p <0.001). When patients were stratified according to the Milan criteria, the presence of these two high-risk radiological findings was associated with a higher tumour recurrence rate in both patients transplanted within the Milan criteria (66.7% vs. 11.6% at three years, p <0.001, n = 68) and those who were transplanted outside the Milan criteria (75.5% vs. 28.6% at three years, p <0.001, n = 32). Radiological features on preoperative hepatobiliary MRI can stratify the risk of tumour recurrence in patients who were transplanted either within or outside the Milan criteria. Therefore, hepatobiliary MRI can be a useful way to select potential candidates for LT. High-risk radiological findings on preoperative hepatobiliary magnetic resonance imaging (either one of the following features: satellite nodule and peritumoural hypointensity on hepatobiliary phase) were associated with a higher tumour recurrence rate in patients transplanted either within or outside the Milan criteria.


Fasting in Ramadan is not associated with deterioration of chronic kidney disease: A prospective observational study.
Although not mandatory for patients, many Muslims fast in Ramadan. We aimed to investigate the effects of long hours (17.5) fasting on renal functions in patients with chronic kidney disease (CKD). Stage 3-5 CKD patients with stable renal function were recruited to this prospective observational study three months ahead of Ramadan in 2015. All patients were instructed regarding possible deleterious effects of dehydration caused by fasting. Forty-five patients (mean age 66.8 ± 10.3 years, 68.8% male) chose to fast and 49 (mean, age: 64.1 ± 12.6 years, 51% male) chose not to fast. Clinical and laboratory data were recorded before and after Ramadan. Baseline clinical and laboratory parameters were similar in the two groups, except for higher serum creatinine and lower estimated glomerular filtration rate (eGFR) in the nonfasting group (2.22 ± 0.99 vs. 1.64 ± 0.41 mg/dL, P <0.001 and 3 1.9 ± 12.4 vs. 42.6 ± 9.8 mL/min, P <0.001, respectively). More than 30% elevation in serum creatinine after Ramadan occurred in 8.8% and 8.1% of fasting and nonfasting patients, respectively (P = 0.9). More than 25% drop eGFR after Ramadan was noted in seven (15.5%) and six (12.2%) fasting and nonfasting patients, respectively (P = 0.642). Patients with ≥ 25% drop in eGFR (13 vs. 81) were older (72.3 ± 8.3 years vs. 64.3 ± 11.7 years, P = 0.020) and more frequently using diuretics (69.2% vs. 35.8%, P = 0.023). In multiple linear regression analysis, only advanced age was found to be associated with ≥25% drop in eGFR after Ramadan in the fasting group. Fasting during Ramadan was not associated with increased risk of declining in renal functions in patients with Stage 3-5 CKD. However, elderly patients may still be under a higher risk.


Intimal alterations in rabbit aortas during the first 6 months of alloxan-induced diabetes.
Diabetes mellitus is a major risk factor for atherosclerosis. Since endothelial alteration is probably associated with the development of atherosclerosis, we questioned whether morphological evidence of endothelial injury could be observed during the first 6 months of diabetes induced by a single intravenous injection of alloxan in normally fed rabbits compared with age-matched controls. Diabetes (plasma glucose greater than 16 mM) was established by 5 days after alloxan injection. Endothelial alterations consistent with injury, including adhesion of white blood cells, platelets, and fibrin-like material to the endothelial surface, were seen in diabetic rabbit aortas by 2 weeks. These alterations became more severe during the next 6 months. Increased endothelial replication in diabetic vessels was shown by the uptake of tritium-labeled thymidine at 2 weeks and at 3 and 6 months. Hyperplasia of intimal smooth muscle cells progressed during 3 months after treatment. About one third of the diabetic rabbits also showed an elevated plasma cholesterol level, which correlated with increased intimal proliferation but not with endothelial injury or replication. The onset of alloxan-induced diabetes in rabbits is associated with nondenuding endothelial injury and subsequent intimal hypertrophy, changes that are consistent with atherogenesis.


Factors associated with waiting time to breast cancer diagnosis among symptomatic breast cancer patients: a population-based study from Ontario, Canada.
A prolonged time from first presentation to cancer diagnosis has been associated with worse disease-related outcomes. This study evaluated potential determinants of a long diagnostic interval among symptomatic breast cancer patients. This was a population-based, cross-sectional study of symptomatic breast cancer patients diagnosed in Ontario, Canada from 2007 to 2015 using administrative health data. The diagnostic interval was defined as the time from the earliest breast cancer-related healthcare encounter before diagnosis to the diagnosis date. Potential determinants of the diagnostic interval included patient, disease and usual healthcare utilization characteristics. We used multivariable quantile regression to evaluate their relationship with the diagnostic interval. We also examined differences in diagnostic interval by the frequency of encounters within the interval. Among 45,967 symptomatic breast cancer patients, the median diagnostic interval was 41 days (interquartile range 20-92). Longer diagnostic intervals were observed in younger patients, patients with higher burden of comorbid disease, recent immigrants to Canada, and patients with higher healthcare utilization prior to their diagnostic interval. Shorter intervals were observed in patients residing in long-term care facilities, patients with late stage disease, and patients who initially presented in an emergency department. Longer diagnostic intervals were characterized by an increased number of physician visits and breast procedures. The identification of groups at risk of longer diagnostic intervals provides direction for future research aimed at better understanding and improving breast cancer diagnostic pathways. Ensuring that all women receive a timely breast cancer diagnosis could improve breast cancer outcomes.


Novel thioredoxin-like proteins are components of a protein complex coating the cortical microtubules of Toxoplasma gondii.
Microtubules are versatile biopolymers that support numerous vital cellular functions in eukaryotes. The specific properties of microtubules are dependent on distinct microtubule-associated proteins, as the tubulin subunits and microtubule structure are exceptionally conserved. Highly specialized microtubule-containing assemblies are often found in protists, which are rich sources for novel microtubule-associated proteins. A protozoan parasite, Toxoplasma gondii, possesses several distinct tubulin-containing structures, including 22 microtubules closely associated with the cortical membrane. Early ultrastructural studies have shown that the cortical microtubules are heavily decorated with associating proteins. However, little is known about the identities of these proteins. Here, we report the discovery of a novel protein, TrxL1 (for Thioredoxin-Like protein 1), and an associating complex that coats the cortical microtubules. TrxL1 contains a thioredoxin-like fold. To visualize its localization in live parasites by fluorescence, we replaced the endogenous TrxL1 gene with an mEmeraldFP-TrxL1 fusion gene. Structured illumination-based superresolution imaging of this parasite line produced a detailed view of the microtubule cytoskeleton. Despite its stable association with the cortical microtubules in the parasite, TrxL1 does not seem to bind to microtubules directly. Coimmunoprecipitation experiments showed that TrxL1 associates with a protein complex containing SPM1, a previously reported microtubule-associated protein in T. gondii. We also found that SPM1 recruits TrxL1 to the cortical microtubules. Besides SPM1, several other novel proteins are found in the TrxL1-containing complex, including TrxL2, a close homolog of TrxL1. Thus, our results reveal for the first time a microtubule-associated complex in T. gondii.


Inactivation of Cdc2 increases the level of apoptosis induced by DNA damage.
A number of lines of evidence have suggested a possible involvement of the mitosis-promoting protein kinase Cdc2 in the process of apoptotic cell death, and one recent study concluded that premature activation of Cdc2 is required for apoptosis. Here we have used a temperature-sensitive murine Cdc2 mutant cell line and Cdc2 inhibitor compounds to study the effect of inhibition of this protein kinase on apoptosis induced by DNA-damaging drugs. Inhibition of Cdc2 activity before or during exposure to DNA strand break-inducing drugs had the effect of increasing the level of subsequent apoptosis, as assessed by electron microscopy and flow cytometry. We conclude that, far from being required for cell death, a form of mammalian Cdc2 suppresses apoptosis induced by DNA damage. This form of Cdc2 appears to be active in G2-arrested cells and is therefore presumably distinct from the mitosis-promoting Cdc2-cyclin B heterodimer.


Very different performance of the power Doppler modalities of several ultrasound machines ascertained by a microvessel flow phantom.
In many patients with rheumatoid arthritis (RA) subclinical disease activity can be detected with ultrasound (US), especially using power Doppler US (PDUS). However, PDUS may be highly dependent on the type of machine. This could create problems both in clinical trials and in daily clinical practice. To clarify how the PDUS signal differs between machines we created a microvessel flow phantom. The flow phantom contained three microvessels (150, 1000, 2000 microns). A syringe pump was used to generate flows. Five US machines were used. Settings were optimised to assess the lowest detectable flow for each US machine. The minimal detectable flow velocities showed very large differences between the machines. Only two of the machines may be able to detect the very low flows in the capillaries of inflamed joints. There was no clear relation with price. One of the lower-end machines actually performed best in all three vessel sizes. We created a flow phantom to test the sensitivity of US machines to very low flows in small vessels. The sensitivity of the power Doppler modalities of 5 different machines was very different. The differences found between the machines are probably caused by fundamental differences in processing of the PD signal or internal settings inaccessible to users. Machines considered for PDUS assessment of RA patients should be tested using a flow phantom similar to ours. Within studies, only a single machine type should be used.


Effect of leukemia inhibitory factor in experimental cisplatin neuropathy in mice.
In this study, the effect of leukemia inhibitory factor (LIF) on cisplatin (CDDP)-induced neuropathy was evaluated. Mice were treated with CDDP, 2 mg/kg i.p. twice a week nine times. During the last week some of the mice were also injected with LIF, 2 mug/kg s.c. every other day for a total of four injections. Development of neuropathy was evaluated with changes in tail flick latency and sensory nerve conduction velocity (NCV). At the end of the treatment period dorsal root ganglia (DRG) were microscopically examined. Some of the DRGs were explanted into extracellular matrix, covered with culture medium and incubated for 3 days. During and at the end of the incubation, cellular migration and axonal outgrowth from the DRGs were quantified. LIF proved effective in reversing the increase in tail flick latency (p<0.05) and improving the reduction in NCV induced by CDDP. CDDP led to smaller nuclear and somatic size in neurons, while with LIF, the latter was restored to control values (p<0.01). No apoptotic nucleus was observed among DRG neurons while very few and moderate numbers detected among satellite and Schwann cells, respectively. With LIF, none of the cells had apoptosis. CDDP caused a decrease in the number of migrating cells and in the length of outgrowing axons while LIF treatment restored both capacities (p<0.05) In conclusion, in CDDP-induced neuropathy, LIF was found to be effective in correcting some functional and morphological deteriorations related with major involvement of Schwann cells.


Use of substance abuse treatment services by persons with mental health and substance use problems.
This study provided population estimates of mental syndromes and substance use problems and examined whether the co-occurrence of mental health and substance use problems was associated with the use of substance abuse treatment services. Study data were drawn from the 1997 National Household Survey on Drug Abuse. Of the total sample of 16,661 adults, 2 percent reported using services for alcohol or drug use problems in the previous year. Among the 3,474 (17 percent) who reported at least one alcohol or drug use problem, 6 percent used substance abuse services. Only 4 percent of persons who reported substance use problems alone received any substance abuse treatment service in the previous year. Only 3 percent of persons who reported alcohol use problems alone received such services. Among persons with one or more substance use problems, the prevalence of service use was 11 percent among persons who reported one co-occurring mental syndrome and 18 percent among those who reported two or more mental syndromes. Multiple logistic regression analyses identified a number of subgroups who might have needed substance abuse services but did not receive them, including women, Asians and Pacific Islanders, college graduates, persons employed full-time, persons who abused alcohol only, and persons with substance use problems who reported no coexisting mental syndromes. The rate of help seeking among persons with alcohol use problems is low, which is a public health concern.


Characterization of rectal, proximal and distal colon cancers based on clinicopathological, molecular and protein profiles.
Accumulating evidence suggests that colorectal cancer (CRC) should be viewed as a heterogeneous disease, with proximal and distal CRCs showing multiple biological and clinical differences. The aim of this study was to develop a clinicopathological, molecular and protein profile for CRCs based on their region and thus providing insight into their heterogeneity. CRC patients (n=399) were evaluated for clinicopathologic and molecular features including K-RAS, BRAF and MSI status. Tumors were also screened for expression of 50 immunohistochemical markers linked to major signaling pathways involved in tumor-progression or immune response. Proximally located tumors show significantly larger tumor size, higher T-stage, higher tumor grade and more frequent mucinous histologic subtype compared to the distal colon and rectum. The frequency of BRAF mutation and MSI-high phenotype were significantly higher in proximal colon cancers. There is a significant difference in regional expression of 10 tumor-associated markers (CDX2, CD44v6, CD44s, TOPK, nuclear beta-catenin, pERK, APAF-1, E-cadherin, p21 and bcl2) and 4 immune response markers (CD68, CD163, FoxP3 and TIA-1). In multivariate analysis CD44s, CD44v6, nuclear beta-catenin and CD68 expression was found to best discriminate left- versus right-sided colon cancers. Tumor diameter, pT stage and MSI status best distinguish right-sided colon cancers from rectal cancers and pT stage and E-cadherin best discriminate left-sided colon cancers and rectal cancers. These data along with existing evidence for the presence of distinct regional embryological origin and gene expression profile are highly supportive of the concept that proximal and distal CRCs are distinct clinicopathologic entities.


6th College of Surgeons lecture: the philosophy of balance: the art of healing.
With the rise of high tech medicine, and emphasis on the scientific aspects of medicine, there is danger that we may lose the balanced approach to healing, and lose the benefit of the traditional medical wisdom and emotional support, to improve the care of our patients. Allopathic or the mainstream medicine (Western medicine) is not the only way. With over-emphasis on the anatomy and pathology, the biochemistry and the molecular biology, we tend to treat the disease, and somehow neglect the patient. That is one of the reasons why many patients still turn to alternative medicine to relieve their ailments.We need to remember that the patient is a person, consisting of not just the body, but also the mind and the spirit. We therefore need to treat not just the body but also the mind and to heal the spirit. That would be the balanced approach in the management of patients. To treat our patients optimally, we need to understand the natural history of diseases, and not make our treatment worse than the disease itself, carefully balancing the risks and benefits in our treatment for that individual patient. The mind has more influence over the body in health and diseases than we used to think. We need to be optimistic and give patients hope through counseling, and help to minimise the harmful effects of stress and anxiety on the body. It is as important to improve the immunity of the body to diseases (infection as well as cancer) as to get rid of every bacteria or cancer cell. It may not be possible to get rid of all the cancer cells in the body, but it may be possible to keep them under control. The most important factor in improving the immunity is for the patient to have a relaxed mind. He would need emotional support from family and friends. Exercise, proper diet with plenty of fresh fruits and vegetables would help to improve immunity and speed up the healing process. The art of healing is the art of balancing the Science and the Art of Medicine, treating the disease and the patient as a whole, incorporating the best in allopathic (Western) medicine as well as complementary medical practices. With this, we hope to provide the best care to our patients.


Association of tumour mutational burden with outcomes in patients with advanced solid tumours treated with pembrolizumab: prospective biomarker analysis of the multicohort, open-label, phase 2 KEYNOTE-158 study.
Tumour mutational burden (TMB) has been retrospectively correlated with response to immune checkpoint blockade. We prospectively explored the association of high tissue TMB (tTMB-high) with outcomes in ten tumour-type-specific cohorts from the phase 2 KEYNOTE-158 study, which assessed the anti-PD-1 monoclonal antibody pembrolizumab in patients with selected, previously treated, advanced solid tumours. In the multi-cohort, open-label, non-randomised, phase 2 KEYNOTE-158 study, patients were enrolled from 81 academic facilities and community-based institutions across 21 countries in Africa, the Americas, Asia, and Europe. Eligible patients were aged 18 years or older, had a histologically or cytologically confirmed advanced (ie, unresectable or metastatic, or both) incurable solid tumour (eligible tumour types were anal, biliary, cervical, endometrial, mesothelioma, neuroendocrine, salivary, small-cell lung, thyroid, and vulvar), progression on or intolerance to one or more lines of standard therapy, had measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1) assessed by independent central radiological review, Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of at least 3 months, adequate organ function, and a tumour sample for biomarker analysis. Participants were given pembrolizumab 200 mg intravenously every 3 weeks for up to 35 cycles. Tissue TMB (tTMB) was assessed in formalin-fixed paraffin-embedded tumour samples using the FoundationOne CDx assay (Foundation Medicine, Cambridge, MA, USA). The prespecified definition of tTMB-high status was at least 10 mutations per megabase. The primary endpoint was the proportion of patients with an objective response (complete or partial response) as per Response Evaluation Criteria in Solid Tumours (version 1.1) by independent central review. This prespecified analysis assessed the association between antitumour activity and tTMB in treated patients with evaluable tTMB data. Efficacy was assessed in all participants who received at least one dose of pembrolizumab, had evaluable tTMB data, and were enrolled at least 26 weeks before data cutoff (June 27, 2019), and safety was assessed in all participants who received at least one dose of pembrolizumab and had tTMB-high status. KEYNOTE-158 is registered at ClinicalTrials.gov, NCT02628067, and is ongoing. Between Jan 15, 2016, and June 25, 2019, 1073 patients were enrolled. 1066 participants were treated as of data cutoff (June 27, 2019), of whom 805 (76%) were evaluable for TMB, and 105 (13%) of 805 had tTMB-high status and were assessed for safety. 1050 (98%) of 1066 patients enrolled by at least 26 weeks before data cutoff, of whom 790 (75%) were evaluable for TMB and included in efficacy analyses. 102 (13%) of these 790 patients had tTMB-high status (≥10 mutations per megabase), and 688 (87%) patients had non-tTMB-high status (<10 mutations per megabase). Median study follow-up was 37·1 months (IQR 35·0-38·3). Objective responses were observed in 30 (29%; 95% CI 21-39) of 102 patients in the tTMB-high group and 43 (6%; 5-8) of 688 in the non-tTMB-high group. 11 (10%) of 105 patients had treatment-related serious adverse events. 16 (15%) participants had a grade 3-5 treatment-related adverse event, of which colitis was the only such adverse event that occurred in more than one patient (n=2). One patient had fatal pneumonia that was assessed by the investigator to be treatment related. tTMB-high status identifies a subgroup of patients who could have a robust tumour response to pembrolizumab monotherapy. tTMB could be a novel and useful predictive biomarker for response to pembrolizumab monotherapy in patients with previously treated recurrent or metastatic advanced solid tumours. Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc.


Altered Immune Activation and IL-23 Signaling in Response to Candida albicans in Autoimmune Polyendocrine Syndrome Type 1.
Autoimmune polyendocrine syndrome type 1 (APS-1) is a rare, childhood onset disease caused by mutations in the autoimmune regulator (AIRE) gene. Chronic mucocutaneous candidiasis (CMC) is one of the three major disease components and is, to date, mainly explained by the presence of neutralizing auto-antibodies against cytokines [interleukin (IL)-17A, IL-17F, and IL-22] from T helper 17 cells, which are critical for the protection against fungal infections. However, patients without current auto-antibodies also present CMC and we, therefore, hypothesized that other immune mechanisms contribute to CMC in APS-1. Whole blood was stimulated with Candida albicans (C. albicans) in a standardized assay, and immune activation was investigated by analyzing 46 secreted immune mediators. Then, peripheral blood mononuclear cells were stimulated with curdlan, a Dectin-1 agonist and IL-23 inducer, and the IL-23p19 response in monocytes was analyzed by flow cytometry. We found an altered immune response in APS-1 patients compared with healthy controls. Patients fail to increase the essential ILs, such as IL-2, IL-17A, IL-22, and IL-23, when stimulating whole blood with C. albicans. A significantly altered IL-23p19 response was detected in patients' monocytes upon stimulation with curdlan. APS-1 patients have an altered immune response to C. albicans including a dysregulation of IL-23p19 production in monocytes. This probably contributes to the selective susceptibility to CMC found in the majority of patients.


Environmental factors influencing epidemic cholera.
Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks.


[Documentation of the diagnostic quality of hospitals: evaluation of autopsy reports].
Multiple factors have affected the decline in autopsy rates. Discrepancies between clinical diagnoses and findings at autopsy are frequently used as an argument for a high autopsy rate. However, the quality of the diagnosis is independent of the autopsy rate. A long-term study covering the years 1972-2002 in the University Hospital Zurich has documented a significant reduction of diagnostic errors in internal medicine. Major diagnostic errors (class 1) declined from 16% (1972), to 9% (1982), to 7% (1992) to 2% (2002). The main reason is the availability of new diagnostic procedures. In 2010 the analysis of class 1 diagnostic errors throughout the hospital documented class 1 discrepancies in only 1%. This low number of diagnostic errors has been published in the annual quality report of the University Hospital Zurich. The documentation of this improvement in the quality report of the hospital provides the opportunity to convince clinicians, health politicians and the hospital administration to support autopsies in teaching as well as non-teaching hospitals.


Hyaluronic acid/chitosan multilayer coatings on neuronal implants for localized delivery of siRNA nanoplexes.
Binding, stabilizing and promoting cellular uptake of siRNA are all critical efforts in creating matrices for the localized delivery of siRNA molecules to target cells. In this study, we describe the generation of chitosan imidazole/siRNA nanoplexes (NPs) embedded in nano scope polyelectrolyte multilayers (PEMs) composed of hyaluronic acid and chitosan for sustained and localized drug delivery. Regular PEM build-up, successful integration of NPs and controlled release under physiological conditions were shown. Biological efficacy was evaluated in neuronal cell culture concerning cell adhesion, viability, NPs uptake and gene silencing. The additionally shown biological functionalization of neuronal implants possesses potential for future applications in the field of regenerative medicine and treatment of spinal cord injuries.


Analogies can speed up the motor learning process.
Analogies have been shown to improve motor learning in various tasks and settings. In this study we tested whether applying analogies can shorten the motor learning process and induce insight and skill improvement in tasks that usually demand many hours of practice. Kinematic measures were used to quantify participant's skill and learning dynamics. For this purpose, we used a drawing task, in which subjects drew lines to connect dots, and a mirror game, in which subjects tracked a moving stimulus. After establishing a baseline, subjects were given an analogy, explicit instructions or no further instruction. We compared their improvement in skill (quantified by coarticulation or smoothness), accuracy and movement duration. Subjects in the analogy and explicit groups improved their coarticulation in the target task, while significant differences were found in the mirror game only at a slow movement frequency between analogy and controls.We conclude that a verbal analogy can be a useful tool for rapidly changing motor kinematics and movement strategy in some circumstances, although in the tasks selected it did not produce better performance in most measurements than explicit guidance. Furthermore, we observed that different movement facets may improve independently from others, and may be selectively affected by verbal instructions. These results suggest an important role for the type of instruction in motor learning.


Species distribution and physiological characterization of Acinetobacter genospecies from healthy human skin of tribal population in India.
Various reports on distribution of Acinetobacter spp. from healthy human skin restricted to urban population. However, no such data is available from healthy human skin of tribal population not exposed to modern antibiotics during their life time. Isolation, biotyping, distribution and physiological characterisation of Acinetobacter spp. from healthy human skin of tribal population. Tribal population of Toranmal area of Satpuda Ranges, Maharashtra, India were sampled for ten body sites. Tentative Acinetobacter isolates were confirmed to the genus level by chromosomal DNA transformation assay and to species level using Bouvet and Grimont system. Novel physiological characteristics like pH, temperature and salt tolerance were studied. All strains were screened for production of various enzymes. One hundred and eighteen strains were isolated, which belonged to nine Acinetobacter genospecies. A. haemolyticus was most abundant followed by A. calcoaceticus and A. genospecies 1-3. Higher percentage of Acinetobacter was recovered from skin of nose, Pawara tribe and female volunteers. They showed wide variation in temperature, salt and pH tolerance. Most of the strains could produce enzymes viz, lipase, esterase, urease and amylase. Acinetobacter spp. belonging to nine genospecies were obtained in the present study. Physiological characteristics including high salt, temperature and acidic pH tolerance were helpful to differentiate between the commensal and pathogenic species of Acinetobacter genus.


Anisotropic ultrasensitive PdTe2-based phototransistor for room-temperature long-wavelength detection.
Emergent topological Dirac semimetals afford fresh pathways for optoelectronics, although device implementation has been elusive to date. Specifically, palladium ditelluride (PdTe2) combines the capabilities provided by its peculiar band structure, with topologically protected electronic states, with advantages related to the occurrence of high-mobility charge carriers and ambient stability. Here, we demonstrate large photogalvanic effects with high anisotropy at terahertz frequency in PdTe2-based devices. A responsivity of 10 A/W and a noise-equivalent power lower than 2 pW/Hz0.5 are achieved at room temperature, validating the suitability of PdTe2-based devices for applications in photosensing, polarization-sensitive detection, and large-area fast imaging. Our findings open opportunities for exploring uncooled and sensitive photoelectronic devices based on topological semimetals, especially in the highly pursuit terahertz band.


Factors influencing childhood obesity - the establishment of a population-wide monitoring system in Germany.
Obesity poses a danger to childhood health and can continue to have a negative impact on health into adulthood. Currently, about 15% of children and adolescents in Germany are overweight or obese. Moreover, significant data on the multifactorial causes of childhood obesity that is systematically recorded, regularly updated and obtainable at the nationwide level are not yet available in Germany. As such, the Robert Koch Institute is establishing a population-wide system to monitor the factors that are relevant to childhood obesity (AdiMon). AdiMon will be available by the end of 2017. This paper outlines the methodological approach that is being used to establish AdiMon and describes the current results of the project (the development of an initial set of core indicators). The project began by undertaking a systematic literature review aimed at piecing together the latest knowledge on factors that influence childhood obesity. The factors that were identified were then sorted according to relevance, and appropriate indicators were selected. This was followed up by research into data sources that - as far as possible - provide significant data that are regularly collected but that also provide for regional differentiation. Work is currently underway to analyse these indicators and data sources. Once this work has been completed, the indicator set will be finalised and the results published on the internet. Population-wide monitoring of factors relevant to childhood obesity takes the following types of indicators into account: behavioural factors (such as physical activity), biological factors (such as genetic predisposition), prenatal and early-childhood factors (such as breastfeeding), psychosocial factors (such as parents' health consciousness), environmental factors (such as playgrounds in the local area), contextual factors (such as a migrant background) and prevention measures as well as measures to promote health (such as expenditure by statutory health insurers). The population-wide monitoring uses the following data sources: epidemiological studies, social sciences surveys, official statistics and geo-information systems, as well as routine, economic and media data. This paper demonstrates that population-wide monitoring can provide significant information about the distribution and causes of obesity in childhood, and thus enable the need for action to be recognised at an early stage, initial approaches for preventive measures to be identified and developments to be tracked over time.


Serum relaxin levels affect the in vivo properties of some but not all tendons in normally menstruating young women.
Relaxin (hRLX) is a hormone reported to affect collagen synthesis. Its effects are also thought to be modulated by other sex hormones, including oestrogen, which has previously been found to be associated with alterations of in vivo tendon properties. There is thus a potential for hRLX to impact on collagen, which could result in tendon structural and mechanical properties being modified. The present study therefore aimed to determine any interaction between hRLX and tendon stiffness, in normally menstruating women (n = 12). Tendon properties were determined using a combination of dynamometry and B-mode ultrasound, whilst serum hRLX levels were established by ELISA. Serum hRLX level was seen to be negatively associated with patellar tendon stiffness (r = -0.56; P < 0.001), explaining 31% of the variance in this parameter. There was no association between hRLX and gastrocnemius tendon stiffness (P > 0.05), or with the cross-sectional area of either of the two tendons (P > 0.05). In young, normally menstruating women, hRLX appears to have a significant effect on the patellar but not the gastrocnemius tendon stiffness. Where it has an effect, this appears to be on the intrinsic properties rather than on the dimensions of said tendon. Future work to elucidate the physiological cause of this selectivity in the impact of relaxin will be key to mapping the impact of the endocrine system on the phenotype of tendinous tissue.


Variable coherence tomography.
By adjusting the spatial coherence of a quasi-monochromatic beam, one can control the distance between two volumes of coherence. We propose to use such a beam in a typical scattering experiment and present a method for determining the degree of spatial correlation of a quasi-homogeneous medium by recording the scattered intensity in only one direction.


Preventing AVF thrombosis: the rationale and design of the Omega-3 fatty acids (Fish Oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) study.
Haemodialysis (HD) is critically dependent on the availability of adequate access to the systemic circulation, ideally via a native arteriovenous fistula (AVF). The Primary failure rate of an AVF ranges between 20-54%, due to thrombosis or failure of maturation. There remains limited evidence for the use of anti-platelet agents and uncertainty as to choice of agent(s) for the prevention of AVF thrombosis. We present the study protocol for a randomised, double-blind, placebo-controlled, clinical trial examining whether the use of the anti-platelet agents, aspirin and omega-3 fatty acids, either alone or in combination, will effectively reduce the risk of early thrombosis in de novo AVF. The study population is adult patients with stage IV or V chronic kidney disease (CKD) currently on HD or where HD is planned to start within 6 months in whom a planned upper or lower arm AVF is to be the primary HD access. Using a factorial-design trial, patients will be randomised to aspirin or matching placebo, and also to omega-3 fatty acids or matching placebo, resulting in four treatment groups (aspirin placebo/omega-3 fatty acid placebo, aspirin/omega-3 fatty acid placebo, aspirin placebo/omega-3 fatty acid, aspirin/omega-3 fatty acid). Randomisation will be achieved using a dynamic balancing method over the two stratification factors of study site and upper versus lower arm AVF. The medication will be commenced pre-operatively and continued for 3 months post surgery. The primary outcome is patency of the AVF at three months after randomisation. Secondary outcome measures will include functional patency at six and twelve months, primary patency time, secondary (assisted) patency time, and adverse events, particularly bleeding. This multicentre Australian and New Zealand study has been designed to determine whether the outcome of surgery to create de novo AVF can be improved by the use of aspirin and/or omega-3 fatty acids. Recently a placebo-controlled trial has shown that clopidogrel is effective in safely preventing primary AVF thrombosis, but ineffective at increasing functional patency. Our study presents significant differences in the anti-platelet agents used, the study design, and surgical and patient demographics that should contribute further evidence regarding the efficacy of anti-platelet agents. Australia & New Zealand Clinical Trials Register (ACTRN12607000569404).


Genomic insights into population history and biological adaptation in Oceania.
The Pacific region is of major importance for addressing questions regarding human dispersals, interactions with archaic hominins and natural selection processes1. However, the demographic and adaptive history of Oceanian populations remains largely uncharacterized. Here we report high-coverage genomes of 317 individuals from 20 populations from the Pacific region. We find that the ancestors of Papuan-related ('Near Oceanian') groups underwent a strong bottleneck before the settlement of the region, and separated around 20,000-40,000 years ago. We infer that the East Asian ancestors of Pacific populations may have diverged from Taiwanese Indigenous peoples before the Neolithic expansion, which is thought to have started from Taiwan around 5,000 years ago2-4. Additionally, this dispersal was not followed by an immediate, single admixture event with Near Oceanian populations, but involved recurrent episodes of genetic interactions. Our analyses reveal marked differences in the proportion and nature of Denisovan heritage among Pacific groups, suggesting that independent interbreeding with highly structured archaic populations occurred. Furthermore, whereas introgression of Neanderthal genetic information facilitated the adaptation of modern humans related to multiple phenotypes (for example, metabolism, pigmentation and neuronal development), Denisovan introgression was primarily beneficial for immune-related functions. Finally, we report evidence of selective sweeps and polygenic adaptation associated with pathogen exposure and lipid metabolism in the Pacific region, increasing our understanding of the mechanisms of biological adaptation to island environments.


Development of a dual-energy X-ray absorptiometry-derived body volume equation in Hispanic adults for administering a four-compartment model.
The purpose of the present study was: (1) to develop a new dual-energy X-ray absorptiometry (DXA)-derived body volume (BV) equation with the GE-Lunar prodigy while utilising underwater weighing (UWW) as a criterion and (2) to cross-validate the novel DXA-derived BV equation (4C-DXANickerson), Wilson DXA-derived BV equation (4C-DXAWilson) and air displacement plethysmography (ADP)-derived BV (4C-ADP) in Hispanic adults. A total of 191 Hispanic adults (18-45 years) participated in the present study. The development sample consisted of 120 females and males (50 % females), whereas the cross-validation sample comprised of forty-one females and thirty males (n 71). Criterion body fat percentage (BF %) and fat-free mass (FFM) were determined using a four-compartment (4C) model with UWW as a criterion for BV (4C-UWW). 4C-DXANickerson, 4C-DXAWilson and 4C-ADP were compared against 4C-UWW in the cross-validation sample. 4C-DXANickerson, 4C-DXAWilson and 4C-ADP all produced similar validity statistics when compared with 4C-UWW in Hispanic males (all P > 0·05). 4C-DXANickerson also yielded similar BF % and FFM values as 4C-UWW when evaluating the mean differences (constant error (CE)) in Hispanic females (CE = -0·79 % and 0·38 kg; P = 0·060 and 0·174, respectively). However, 4C-DXAWilson produced significantly different BF % and FFM values (CE = 3·22 % and -2·20 kg, respectively; both P < 0·001). Additionally, 4C-DXAWilson yielded significant proportional bias when estimating BF % (P < 0·001), whereas 4C-ADP produced significant proportional bias for BF % and FFM (both P < 0·05) when evaluated in Hispanic females. The present study findings demonstrate that 4C-DXANickerson is a valid measure of BV in Hispanics and is recommended for use in clinics, where DXA is the main body composition assessment technique.


Helping without harming: the instructor's feedback dilemma in debriefing--a case study.
Simulation instructors often feel caught in a task-versus-relationship dilemma. They must offer clear feedback on learners' task performance without damaging their relationship with those learners, especially in formative simulation settings. Mastering the skills to resolve this dilemma is crucial for simulation faculty development. We conducted a case study of a debriefer stuck in this task-versus-relationship dilemma. The "2-column case" captures debriefing dialogue and instructor's thoughts and feelings or the "subjective experience." The "learning pathways grid" guides a peer group of faculty in a step-by-step, retrospective analysis of the debriefing. The method uses vivid language to highlight the debriefer's dilemmas and how to surmount them. The instructor's initial approach to managing the task-versus-relationship dilemma included (1) assuming that honest critiques will damage learners, (2) using vague descriptions of learner actions paired with guess-what-I-am-thinking questions, and (3) creating a context she worried would leave learners feeling neither safe nor clear how they could improve. This case study analysis identified things the instructor could do to be more effective including (1) making generous inferences about the learners' qualities, (2) normalizing the challenges posed by the simulation, (3) assuming there are different understandings of what it means to be a team. There are key assumptions and ways of interacting that help instructors resolve the task-versus-relationship dilemma. The instructor can then provide honest feedback in a rigorous yet empathic way to help sustain good or improve suboptimal performance in the future.


Disruption of the sarcolemma of mammalian skeletal muscle fibers by homogenization.
A new method has been developed for mechanically disrupting the sarcolemma of mammalian sketletal muscle fibers (sarcolemma nonfunctional). Single fibers were produced from small pieces of the soleus muscle of the rabbit by gentle homogenization in a relaxing solution in a tissue homogenizer. These fibers were found to be longitudinally intact, with a sarcomere spacing of approximately 2.1 mum, permeable to large molecules of 10,000 MW, sensitive to the chemical stimuli that cause Ca2+ to be released from the sarcoplasmic reticulum, and responsive to Ca2+ in the same manner as frog fibers skinned in the traditional manner. The single fibers were mounted in a tension transducer and steady-state tensions were recorded in test solutions of different Ca2+ concentrations. The data did not differ statistically from data similarly obtained in identically prepared fibers that, in addition, we had longitudinally split in half to ensure disruption of the sarcolemmal barrier to the diffusion of ions.


Vapors Are Lost to Walls, Not to Particles on the Wall: Artifact-Corrected Parameters from Chamber Experiments and Implications for Global Secondary Organic Aerosol.
Atmospheric models of secondary organic aerosol (OA) (SOA) typically rely on parameters derived from environmental chambers. Chambers are subject to experimental artifacts, including losses of (1) particles to the walls (PWL), (2) vapors to the particles on the wall (V2PWL), and (3) vapors to the wall directly (VWL). We present a method for deriving artifact-corrected SOA parameters and translating these to volatility basis set (VBS) parameters for use in chemical transport models (CTMs). Our process involves combining a box model that accounts for chamber artifacts (Statistical Oxidation Model with a TwO-Moment Aerosol Sectional model (SOM-TOMAS)) with a pseudo-atmospheric simulation to develop VBS parameters that are fit across a range of OA mass concentrations. We found that VWL led to the highest percentage change in chamber SOA mass yields (high NOx: 36-680%; low NOx: 55-250%), followed by PWL (high NOx: 8-39%; low NOx: 10-37%), while the effects of V2PWL are negligible. In contrast to earlier work that assumed that V2PWL was a meaningful loss pathway, we show that V2PWL is an unimportant SOA loss pathway and can be ignored when analyzing chamber data. Using our updated VBS parameters, we found that not accounting for VWL may lead surface-level OA to be underestimated by 24% (0.25 μg m-3) as a global average or up to 130% (9.0 μg m-3) in regions of high biogenic or anthropogenic activity. Finally, we found that accurately accounting for PWL and VWL improves model-measurement agreement for fine mode aerosol mass concentrations (PM2.5) in the GEOS-Chem model.


The affinity threshold for antigenic triggering differs for tolerance susceptible immature precursors vs mature primary B cells.
The specificity of antibody responses is dependent on the extent to which a given antigen selectively stimulates cells from within a diverse B cell repertoire. Previous studies have shown that the triggering of B cells by T cell-dependent antigens is a highly discriminatory process, and that tolerance induction of immature B cells by antigen is equally discriminatory. This symmetry in the requirements for stimulation and tolerance induction could provide a basis for the capacity of antibody responses to discriminate among foreign antigens and yet minimize self recognition. The extent to which this potential for discriminate recognition is applicable to the mature immune system remains controversial, because B cells reactive to self antigens have been identified and, in addition, several investigators have identified heteroclitic immune responses, such as the response to NP of Ighb mice, wherein antibodies are found with higher affinities for analogues of the immunogen than for the immunogen itself. To further investigate the capacity of B cells to discriminate among closely related antigenic determinants, we analyzed the fine specificity and idiotypic distribution of monoclonal antibodies derived from both splenic B cells and immature sIg- bone marrow B cell precursors stimulated in fragment culture with NP-Hy and its structural analogues NIP-Hy and NNP-Hy. The results indicate that the majority of responsive B cells discriminate among these haptenic determinants; however, lambda-bearing B cells responsive to the NP and NIP determinants represent a highly overlapping set of clonotypes. Comparison of the responses to NP-Hy and NIP-Hy of splenic vs sIg- precursors of this clonotype family suggests that the T cell-dependent stimulation of both mature and immature B cells by antigen is highly affinity dependent. Significantly, the affinity thresholds for both stimulation and tolerance induction of immature B cells appears to be higher than that required for the stimulation of mature splenic B cells. Such a disparity in the requisites for triggering mature vs immature B cells could readily account for the presence of low-affinity self-reactive B cells in the mature B cell pools of normal individuals.


Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy.
Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right-sided cancer. To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring) were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT) to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions) over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol) was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed) and 36 patients with right-sided cancer (controls)] were enrolled. Dose-volume histogram (DVH) [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46). In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03) and anterolateral (17.1% versus 2.8%, P=0.049) walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS) of>3 was observed in twelve cases (34.3%), while in five of the controls (13.9%),(Odds ratio=1.3). There was no significant difference between the groups regarding left ventricular ejection fraction. The risk of radiation induced myocardial perfusion abnormality in patients treated with CRT on the left hemi thorax is not low. It is reasonable to minimize the volume of the heart being in the field of radiation employing didactic radiation planning techniques. Also it is advisable to screen these patients with MPI-SPECT, even if they are clinically asymptomatic, as early diagnosis and treatment of silent ischemia may change the outcome.


Effects of UV radiation on aquatic ecosystems and interactions with other environmental factors.
Interactions between climate change and UV radiation are having strong effects on aquatic ecosystems due to feedback between temperature, UV radiation, and greenhouse gas concentration. Higher air temperatures and incoming solar radiation are increasing the surface water temperatures of lakes and oceans, with many large lakes warming at twice the rate of regional air temperatures. Warmer oceans are changing habitats and the species composition of many marine ecosystems. For some, such as corals, the temperatures may become too high. Temperature differences between surface and deep waters are becoming greater. This increase in thermal stratification makes the surface layers shallower and leads to stronger barriers to upward mixing of nutrients necessary for photosynthesis. This also results in exposure to higher levels of UV radiation of surface-dwelling organisms. In polar and alpine regions decreases in the duration and amount of snow and ice cover on lakes and oceans are also increasing exposure to UV radiation. In contrast, in lakes and coastal oceans the concentration and colour of UV-absorbing dissolved organic matter (DOM) from terrestrial ecosystems is increasing with greater runoff from higher precipitation and more frequent extreme storms. DOM thus creates a refuge from UV radiation that can enable UV-sensitive species to become established. At the same time, decreased UV radiation in such surface waters reduces the capacity of solar UV radiation to inactivate viruses and other pathogens and parasites, and increases the difficulty and price of purifying drinking water for municipal supplies. Solar UV radiation breaks down the DOM, making it more available for microbial processing, resulting in the release of greenhouse gases into the atmosphere. In addition to screening solar irradiance, DOM, when sunlit in surface water, can lead to the formation of reactive oxygen species (ROS). Increases in carbon dioxide are in turn acidifying the oceans and inhibiting the ability of many marine organisms to form UV-absorbing exoskeletons. Many aquatic organisms use adaptive strategies to mitigate the effects of solar UV-B radiation (280-315 nm), including vertical migration, crust formation, synthesis of UV-absorbing substances, and enzymatic and non-enzymatic quenching of ROS. Whether or not genetic adaptation to changes in the abiotic factors plays a role in mitigating stress and damage has not been determined. This assessment addresses how our knowledge of the interactive effects of UV radiation and climate change factors on aquatic ecosystems has advanced in the past four years.


Toward the optimal strategy for sustained weight loss in overweight cancer survivors: a systematic review of the literature.
To gain more insight into the optimal strategy to achieve weight loss and weight loss maintenance in overweight and obese cancer survivors after completion of initial treatment, this systematic review aimed to provide an overview of the literature on intervention effects on weight, to describe intervention components used in effective interventions, to identify and synthesize behaviour change techniques (BCTs) and to assess the frequency with which these BCTs were used in effective interventions. Six databases were searched for original research articles describing weight changes in adult overweight cancer survivors after participation in a lifestyle intervention initiated after completion of initial treatment. Two researchers independently screened the retrieved papers and extracted BCTs using the BCT Taxonomy version 1. Thirty-two papers describing 27 interventions were included. Interventions that were evaluated with a robust study design (n = 8) generally showed <5% weight loss and did not evaluate effects at ≥12 months after intervention completion. Effective interventions promoted both diet and physical activity and used the BCTs 'goal setting (behaviour)', 'action planning', 'social support (unspecified)' and 'instruction on how to perform the behaviour'. The results of this first review on intervention components of effective interventions could be used to inform intervention development and showed a need for future publications to report long-term effects, a detailed intervention description and an extensive process evaluation. This study contributed to increasing knowledge on the optimal strategy to achieve weight loss, which is recommended for overweight cancer survivors to improve health outcomes.


Short-term high-dose atorvastatin for periprocedural myocardial infarction prevention in patients with renal dysfunction.
Short-term high-dose atorvastatin administered before percutaneous coronary intervention (PCI) reduces the rate of periprocedural myocardial infarction (pMI) in high-risk patients, such as those with acute coronary syndromes and those with elevated high-sensitivity C-reactive protein. It is unknown whether short-term high-dose administration reduces the rate of pMI in patients with chronic kidney disease. Recently, we observed that in 304 patients with estimated creatinine clearance less than 60 ml/min randomized to receive 80 mg/day of atorvastatin or placebo for 48 h before elective coronary angiography and/or angioplasty, statin administration did not reduce contrast-induced nephropathy (CIN). In this post-hoc analysis, we evaluate the pMI in the subgroup of 161 patients who underwent PCI. In all patients, creatine kinase myocardial isoenzyme (CK-MB) [upper reference limit (URL) 5 ng/ml] was assessed before and at 12 and 24 h after PCI. The pMI, defined as CK-MB elevation more than three times the URL, occurred in 27 (17%) patients. The incidence of pMI was 10.4% (of 77 patients) in the atorvastatin and 23% (of 84 patients) in the placebo group (P < 0.05). Multivariate analysis identified the pretreatment with high-dose atorvastatin as an independent predictor of reduced risk of pMI [odds ratio 0.39, 95% confidence interval 0.16-0.96, P < 0.05]. This post-hoc analysis shows that short-term high-dose atorvastatin administration reduced pMI in patients with renal dysfunction submitted to elective PCI, but without benefit regarding CIN prevention.


Towards an in-depth characterization of Symbiodiniaceae in tropical giant clams via metabarcoding of pooled multi-gene amplicons.
High-throughput sequencing is revolutionizing our ability to comprehensively characterize free-living and symbiotic Symbiodiniaceae, a diverse dinoflagellate group that plays a critical role in coral reef ecosystems. Most studies however, focus on a single marker for metabarcoding Symbiodiniaceae, potentially missing important ecological traits that a combination of markers may capture. In this proof-of-concept study, we used a small set of symbiotic giant clam (Tridacna maxima) samples obtained from nine French Polynesian locations and tested a dual-index sequence library preparation method that pools and simultaneously sequences multiple Symbiodiniaceae gene amplicons per sample for in-depth biodiversity assessments. The rationale for this approach was to allow the metabarcoding of multiple genes without extra costs associated with additional single amplicon dual indexing and library preparations. Our results showed that the technique effectively recovered very similar proportions of sequence reads and dominant Symbiodiniaceae clades among the three pooled gene amplicons investigated per sample, and captured varying levels of phylogenetic resolution enabling a more comprehensive assessment of the diversity present. The pooled Symbiodiniaceae multi-gene metabarcoding approach described here is readily scalable, offering considerable analytical cost savings while providing sufficient phylogenetic information and sequence coverage.


Critically ill patients with severe acute respiratory syndrome.
Severe acute respiratory syndrome (SARS) is a newly recognized infectious disease capable of causing severe respiratory failure. To determine the epidemiological features, course, and outcomes of patients with SARS-related critical illness. Retrospective case series of 38 adult patients with SARS-related critical illness admitted to 13 intensive care units (ICUs) in the Toronto area between the onset of the outbreak and April 15, 2003. Data were collected daily during the first 7 days in the ICUs, and patients were followed up for 28 days. The primary outcome was mortality at 28 days after ICU admission. Secondary outcomes included rate of SARS-related critical illness, number of tertiary care ICUs and staff placed under quarantine, and number of health care workers (HCWs) contracting SARS secondary to ICU-acquired transmission. Of 196 patients with SARS, 38 (19%) became critically ill, 7 (18%) of whom were HCWs. The median (interquartile range [IQR]) age of the 38 patients was 57.4 (39.0-69.6) years. The median (IQR) duration between initial symptoms and admission to the ICU was 8 (5-10) days. Twenty-nine (76%) required mechanical ventilation and 10 of these (34%) experienced barotrauma. Mortality at 28 days was 13 (34%) of 38 patients and for those requiring mechanical ventilation, mortality was 13 (45%) of 29. Six patients (16%) remained mechanically ventilated at 28 days. Two of these patients had died by 8 weeks' follow-up. Patients who died were more often older, had preexisting diabetes mellitus, and on admission to hospital were more likely to have bilateral radiographic infiltrates. Transmission of SARS in 6 study ICUs led to closure of 73 medical-surgical ICU beds. In 2 university ICUs, 164 HCWs were quarantined and 16 (10%) developed SARS. Critical illness was common among patients with SARS. Affected patients had primarily single-organ respiratory failure, and half of mechanically ventilated patients died. The SARS outbreak greatly strained regional critical care resources.


Comparison of hirudin and heparin as adjuncts to streptokinase thrombolysis in a canine model of coronary thrombosis.
Recombinant desulfatohirudin (HI), a potent and specific thrombin inhibitor, was compared with heparin (HE) as an adjunct to streptokinase thrombolysis. In pentobarbital-anesthetized dogs, an occlusive thrombus (whole blood+thrombin) was introduced into the left anterior descending coronary artery (LAD) with superimposed endothelial damage and distal high-grade stenosis. Intravenous infusion of saline (vehicle), HI (0.3 mg/kg followed by 0.3 mg/kg per hour, 1 mg/kg followed by 1 mg/kg per hour, or 2 mg/kg followed by 2 mg/kg per hour), or HE (60 units/kg followed by 40 units/kg per hour or 100 units/kg followed by 60 units/kg per hour) was initiated 15 minutes before streptokinase (750,000 units for 60 minutes) administration. Vessel patency was monitored for 180 minutes after streptokinase administration with a volume flow probe on the proximal LAD. In dogs treated with no adjunctive agent (saline control), none of the vessels were recanalized with streptokinase. Both HI and HE promoted reperfusion, inhibited reocclusion, and reduced the residual thrombus mass in a dose-dependent fashion. However, at comparable levels of therapeutic anticoagulation (activated partial thromboplastin time [APTT] = 1.5-2.0 times baseline) HI exhibited a higher incidence of reperfusion (eight of eight dogs [100%] versus one of eight dogs [12%]), a shorter time to reperfusion (33 +/- 6 versus 59 minutes), a longer duration of initial reperfusion (106 +/- 21 versus 10 minutes), and a smaller residual thrombus mass than did HE. Likewise, the slope of the relation between the APTT prolongation and the total reperfusion time ("anticoagulation/antithrombosis profile") was almost five times higher for the combined HI data than for the HE data. Our results indicate that HI is more effective than HE in enhancing and sustaining coronary recanalization with streptokinase at a HI dose that modestly prolongs coagulation time and does not alter bleeding times.


Interactions of concanavalin A with glycoproteins. A quantitative precipitation study of concanavalin A with the soybean agglutinin.
Certain oligomannose-type glycopeptides have been previously shown to be bivalent for binding to concanavalin A and capable of precipitating the lectin by forming homogeneous cross-linked lattices [L. Bhattacharyya, M. I. Khan, and C.F. Brewer, Biochemistry, 27 (1988) 8762-8767]. In the present study, the effect of protein environment on the binding properties of an oligomannose-type oligosaccharide has been examined through quantitative precipitation analysis of the interactions of concanavalin A (Con A) with the soybean (Glycine max) agglutinin (SBA), which is a tetrameric glycoprotein possessing a single Man9-oligomannose chain per monomer. The results showed that SBA forms two different types of cross-linked complexes with tetrameric Con A, depending on the relative ratio of the two molecules in solution. At a concentration of one equivalent or less, SBA forms a 1:1 complex with Con A. At concentrations exceeding one equivalent, SBA forms a 2:1 complex with Con A. However, SBA forms only 1:1 cross-linked complexes with dimeric forms of Con A, such as acetyl- and succinyl-Con A. The results demonstrated that the total valency of the carbohydrate of SBA is a function of both the quaternary structure of Con A, as well as the relative ratio of SBA to Con A. In addition, the individual Man9-oligosaccharide, which as a glycopeptide is bivalent for binding to Con A, expresses univalency when present on the protein matrix of SBA.


[Using Web 2.0 technologies and social media for the cardiologist's education and update].
The features and tools of Web 2.0 are increasingly introduced and used in the medical field. RSS feeds, podcasts, blogs, online social networks, and social media are proposed as innovative tools for the education and update of clinicians, physicians, nurses, and medical students because of their easy and widespread use. Cardiology area is one of the medical fields where they have been successfully applied. Medical journals such as Circulation and the Journal of the American College of Cardiology, and scientific societies such as the American College of Cardiology and the European Society of Cardiology are using these new and powerful communication tools. In addition, blogs and social networks have been developed to allow physicians to distribute, share, and comment medical contents (images, videos, slides, scientific abstracts, clinical trials updates) concerning issues related to cardiology and cardiovascular diseases. This review provides some background on the evolution of Web 2.0 and social media and describes the most interesting applications of Web 2.0 (and its features) both in the medical and cardiology fields.


The Estrogen Receptor Cofactor SPEN Functions as a Tumor Suppressor and Candidate Biomarker of Drug Responsiveness in Hormone-Dependent Breast Cancers.
The treatment of breast cancer has benefitted tremendously from the generation of estrogen receptor-α (ERα)-targeted therapies, but disease relapse continues to pose a challenge due to intrinsic or acquired drug resistance. In an effort to delineate potential predictive biomarkers of therapy responsiveness, multiple groups have identified several uncharacterized cofactors and interacting partners of ERα, including Split Ends (SPEN), a transcriptional corepressor. Here, we demonstrate a role for SPEN in ERα-expressing breast cancers. SPEN nonsense mutations were detectable in the ERα-expressing breast cancer cell line T47D and corresponded to undetectable protein levels. Further analysis of 101 primary breast tumors revealed that 23% displayed loss of heterozygosity at the SPEN locus and that 3% to 4% harbored somatically acquired mutations. A combination of in vitro and in vivo functional assays with microarray-based pathway analyses showed that SPEN functions as a tumor suppressor to regulate cell proliferation, tumor growth, and survival. We also found that SPEN binds ERα in a ligand-independent manner and negatively regulates the transcription of ERα targets. Moreover, we demonstrate that SPEN overexpression sensitizes hormone receptor-positive breast cancer cells to the apoptotic effects of tamoxifen, but has no effect on responsiveness to fulvestrant. Consistent with these findings, two independent datasets revealed that high SPEN protein and RNA expression in ERα-positive breast tumors predicted favorable outcome in patients treated with tamoxifen alone. Together, our data suggest that SPEN is a novel tumor-suppressor gene that may be clinically useful as a predictive biomarker of tamoxifen response in ERα-positive breast cancers.


Sequential pH-driven dimerization and stabilization of the N-terminal domain enables rapid spider silk formation.
The mechanisms controlling the conversion of spider silk proteins into insoluble fibres, which happens in a fraction of a second and in a defined region of the silk glands, are still unresolved. The N-terminal domain changes conformation and forms a homodimer when pH is lowered from 7 to 6; however, the molecular details still remain to be determined. Here we investigate site-directed mutants of the N-terminal domain from Euprosthenops australis major ampullate spidroin 1 and find that the charged residues D40, R60 and K65 mediate intersubunit electrostatic interactions. Protonation of E79 and E119 is required for structural conversions of the subunits into a dimer conformation, and subsequent protonation of E84 around pH 5.7 leads to the formation of a fully stable dimer. These residues are highly conserved, indicating that the now proposed three-step mechanism prevents premature aggregation of spidroins and enables fast formation of spider silk fibres in general.


Performance on the dementia rating scale in Parkinson's disease with dementia and dementia with Lewy bodies: comparison with progressive supranuclear palsy and Alzheimer's disease.
The relation between dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD) is unknown. To compare the cognitive profiles of patients with DLB and PDD, and compare those with the performance of patients with a subcortical dementia (progressive supranuclear palsy) and a cortical dementia (Alzheimer's disease). Survey of cognitive features. General community in Rogaland county, Norway, and a university dementia and movement disorder research centre in the USA. 60 patients with DLB, 35 with PDD, 49 with progressive supranuclear palsy, and 29 with Alzheimer's disease, diagnosed by either standardised clinical procedures and criteria (all PDD and Alzheimer cases and 76% of cases of progressive supranuclear palsy), or necropsy (all DLB cases and 24% of cases of progressive supranuclear palsy). Level of dementia severity was matched using the total score on the dementia rating scale adjusted for age and education. Dementia rating scale subscores corrected for age. No significant differences between the dementia rating scale subscores in the PDD and DLB groups were found in the severely demented patients; in patients with mild to moderate dementia the conceptualisation subscore was higher in PDD than in DLB (p = 0.03). Compared with Alzheimer's disease, PDD and DLB had higher memory subscores (p < 0.001) but lower initiation and perseveration (p = 0.008 and p=0.021) and construction subscores (p = 0.009 and p = 0.001). DLB patients had a lower conceptualisation subscore (p = 0.004). Compared with progressive supranuclear palsy, PDD and DLB patients had lower memory subscores (p < 0.001). The cognitive profiles of patients with DLB and PDD were similar, but they differed from those of patients with Alzheimer's disease and progressive supranuclear palsy. The cognitive pattern in DLB and PDD probably reflects the superimposition of subcortical deficits upon deficits typically associated with Alzheimer's disease.


Phase I First-in-Human Study of Venetoclax in Patients With Relapsed or Refractory Non-Hodgkin Lymphoma.
Purpose B-cell leukemia/lymphoma-2 (BCL-2) overexpression is common in many non-Hodgkin lymphoma (NHL) subtypes. A phase I trial in patients with NHL was conducted to determine safety, pharmacokinetics, and efficacy of venetoclax, a selective, potent, orally bioavailable BCL-2 inhibitor. Patients and Methods A total of 106 patients with relapsed or refractory NHL received venetoclax once daily until progressive disease or unacceptable toxicity at target doses from 200 to 1,200 mg in dose-escalation and safety expansion cohorts. Treatment commenced with a 3-week dose ramp-up period for most patients in dose-escalation cohorts and for all patients in safety expansion. Results NHL subtypes included mantle cell lymphoma (MCL; n = 28), follicular lymphoma (FL; n = 29), diffuse large B-cell lymphoma (DLBCL; n = 34), DLBCL arising from chronic lymphocytic leukemia (Richter transformation; n = 7), Waldenström macroglobulinemia (n = 4), and marginal zone lymphoma (n = 3). Venetoclax was generally well tolerated. Clinical tumor lysis syndrome was not observed, whereas laboratory tumor lysis syndrome was documented in three patients. Treatment-emergent adverse events were reported in 103 patients (97%), a majority of which were grade 1 to 2 in severity. Grade 3 to 4 events were reported in 59 patients (56%), and the most common were hematologic, including anemia (15%), neutropenia (11%), and thrombocytopenia (9%). Overall response rate was 44% (MCL, 75%; FL, 38%; DLBCL, 18%). Estimated median progression-free survival was 6 months (MCL, 14 months; FL, 11 months; DLBCL, 1 month). Conclusion Selective targeting of BCL-2 with venetoclax was well tolerated, and single-agent activity varied among NHL subtypes. We determined 1,200 mg to be the recommended single-agent dose for future studies in FL and DLBCL, with 800 mg being sufficient to consistently achieve durable response in MCL. Additional investigations including combination therapy to augment response rates and durability are ongoing.


Transforming Growth Factor β/activin signalling induces epithelial cell flattening during Drosophila oogenesis.
Although the regulation of epithelial morphogenesis is essential for the formation of tissues and organs in multicellular organisms, little is known about how signalling pathways control cell shape changes in space and time. In the Drosophila ovarian epithelium, the transition from a cuboidal to a squamous shape is accompanied by a wave of cell flattening and by the ordered remodelling of E-cadherin-based adherens junctions. We show that activation of the TGFβ pathway is crucial to determine the timing, the degree and the dynamic of cell flattening. Within these cells, TGFβ signalling controls cell-autonomously the formation of Actin filament and the localisation of activated Myosin II, indicating that internal forces are generated and used to remodel AJ and to promote cytoskeleton rearrangement. Our results also reveal that TGFβ signalling controls Notch activity and that its functions are partly executed through Notch. Thus, we demonstrate that the cells that undergo the cuboidal-to-squamous transition produce active cell-shaping mechanisms, rather than passively flattening in response to a global force generated by the growth of the underlying cells. Thus, our work on TGFβ signalling provides new insights into the mechanisms through which signal transduction cascades orchestrate cell shape changes to generate proper organ structure.


Association of Decision-making with Patients' Perceptions of Care and Knowledge during Longitudinal Pulmonary Nodule Surveillance.
Patient participation in medical decision-making is widely advocated, but outcomes are inconsistent. We examined the associations between medical decision-making roles, and patients' perceptions of their care and knowledge while undergoing pulmonary nodule surveillance. The study setting was an academically affiliated Veterans Affairs hospital network in which 121 participants had 319 decision-making encounters. The Control Preferences Scale was used to assess patients' decision-making roles. Associations between decision-making, including role concordance (i.e., agreement between patients' preferred and actual roles), shared decision-making (SDM), and perceptions of care and knowledge, were assessed using logistic regression and generalized estimating equations. Participants had a preferred role in 98% of encounters, and most desired an active role (shared or patient controlled). For some encounters (36%), patients did not report their actual decision-making role, because they did not know what their role was. Role concordance and SDM occurred in 56% and 26% of encounters, respectively. Role concordance was associated with greater satisfaction with medical care (adjusted odds ratio [Adj-OR], 5.39; 95% confidence interval [CI], 1.68-17.26), higher quality of patient-reported care (Adj-OR, 2.86; 95% CI, 1.31-6.27), and more disagreement that care could be better (Adj-OR, 2.16; 95% CI, 1.12-4.16). Role concordance was not associated with improved pulmonary nodule knowledge with respect to lung cancer risk (Adj-OR, 1.12; 95% CI, 0.63-2.00) or nodule information received (Adj-OR, 1.13; 95% CI, 0.31-4.13). SDM was not associated with perceptions of care or knowledge. Among patients undergoing longitudinal nodule surveillance, a majority had a preference for having active roles in decision-making. Interestingly, during some encounters, patients did not know what their role was or that a decision was being made. Role concordance was associated with greater patient-reported satisfaction and quality of medical care, but not with improved knowledge. Patient participation in decision-making may influence perceptions of care; however, clinicians may need to focus on other communication strategies or domains to improve patient knowledge and health outcomes.


Potential role of CC chemokine receptor 6 in prediction of late-onset cytomegalovirus infection following solid organ transplant.
CCR6 is a chemokine receptor involved in homing memory T cells, particularly Th17 cells, to sites of mucosal inflammation. Despite the critical role of memory T cells in long-term protective immunity against cytomegalovirus (CMV), a virus that reactivates at multiple mucosal sites, the ability of CCR6 or other Th17 marker expression to predict CMV reactivation following transplantation is not clear. Using 11-color flow cytometry, in this prospective single-center pilot study, we measured the expression of CCR6 and other markers of T-cell function in peripheral blood samples obtained from 21 SOT recipients at the time of discontinuation of anti-CMV prophylaxis. CMV viremia was monitored on a monthly basis after discontinuation of prophylaxis. Eleven patients (52%) developed CMV viremia during the six-month follow-up period. Late-onset CMV infection was preceded by an immune phenotype characterized by increased CCR6 expression on bulk CD4(+) T cells and a reduced number of circulating CMV IE-1-specific Th1 (CD4(+) IFN-γ(+)) cells. Among the markers evaluated, CCR6 was the best single predictor of late-onset CMV infection. Our results suggest that CCR6 expression at the time of discontinuation of antiviral prophylaxis might be a useful predictor of late-onset CMV reactivation and provide the basis for future larger prospective studies.


NADH-linked mitochondrial respiration in the developing mouse brain is sex-, age- and tissue-dependent.
Mitochondria play a major role in the brain. Apart from energy production, mitochondria regulate key factors in the activation of cell signaling pathways such as survival, proliferation, and differentiation. While all these processes occur during the physiological development of the brain, it is surprising that the mitochondrial functions and functioning in the brain during the postnatal development remain poorly explored. In this work, we collected samples of brainstem and cortex of mice at postnatal ages 3 (P3), 21 (P21), and at adulthood (3 months old) and evaluated the mitochondrial oxygen consumption after complex I activation. To do so, we used our oxygraph-2 K system (OROBOROS) that measures the mitochondrial bioenergetics in saponin-permeabilized tissue punches of 2 mg weight. Furthermore, as sex dimorphism in the brain occurs since very early stages of development, we performed experiments in brain samples of male and female mice. Accordingly, the mitochondrial oxygen consumption rate (OCR) was evaluated under activation of complex I (NADH-linked respiration - mitochondrial state 3), and during the inhibition of the complex V (ATP synthase) with oligomycin (mitochondrial state 4). In following, the respiratory control ratio (RCR - state 3/state4) was calculated as an index of mitochondrial oxidative-phosphorylation coupling. Our results show that the activity of the mitochondrial complex I in the brain increases along with the postnatal development in a sex- and tissue-dependent manner, with males showing higher activity than females, and with brainstem tissue showing higher activity than cortex. Our data may contribute to a better understanding of the sex-dependent maturation of the cortex and the cardiorespiratory network located in the brainstem.


Decisions for and against resuscitation in an acute geriatric medicine unit serving the frail elderly.
Recent studies indicate continuing controversy over the appropriateness of intensive care in various clinical settings, particularly for very young and very old patients. We studied decisions regarding cardiopulmonary resuscitation (CPR) and the associated clinical course in an acute geriatric unit serving the frail elderly. Despite multiple acute and chronic conditions, advanced age, and functional impairment, patients overwhelmingly preferred CPR. The patients with do-not-resuscitate (DNR) orders were more functionally dependent, more acutely and chronically ill, and less likely to participate in the decision regarding CPR. The majority of DNR orders were made by surrogates, while the majority of CPR directives were made by the patients themselves. Other forms of acute and supportive care, such as parenteral antibiotics, artificial feeding, and transfusions were not withheld from the DNR patients unless a separate decision to limit a specific treatment was undertaken following consultation between the attending physician and the patient or family. Acuity of illness greater than two SDs above the unit mean and the presence of a surrogate decision maker predicted the majority of DNR orders. Length of stay averaged 28 days for all unit patients, 24 days for patients choosing CPR, and 46 days for patients with DNR orders. The four patients who were resuscitated but died stayed an average of 25 days, while the two survivors of resuscitation stayed 20 and 53 days, respectively. The findings indicate that patients and their families considered appropriate clinical criteria including severity of illness when making their decisions about CPR. Nevertheless, the majority chose to be resuscitated in the event of an arrest. Further studies are needed to explore medical decision making by elderly inpatients and their surrogates and to describe the associated clinical course.


Effective educator-student relationships in nursing education to strengthen nursing students' resilience.
Little research has been conducted in private nursing schools with regard to the educator-student relationship to strengthen the resilience of nursing students and to improve the educator-student relationship. An effective educator-student relationship is a key factor to ensure a positive learning climate where learning can take place and resilience can be strengthened. The purpose was to explore and describe nursing students' view on the basic elements required for an effective educator-student relationship to strengthen their resilience and the educator-student relationship. This study followed an explorative, descriptive and contextual qualitative design in a private nursing education institution in the North West Province. Purposive sampling was used. The sample consisted of 40 enrolled nursing auxiliary students. The World Café Method was used to collect data, which were analysed by means of content analysis. The following five main themes were identified and included: (1) teaching-learning environment, (2) educator-student interaction, (3) educator qualities, (4) staying resilient and (5) strategies to strengthen resilience. Students need a caring and supportive environment; interaction that is constructive, acknowledges human rights and makes use of appropriate non-verbal communication. The educator must display qualities such as love and care, respect, responsibility, morality, patience, being open to new ideas, motivation, willingness to 'go the extra mile' and punctuality. Students reported on various ways how they manage to stay resilient. It thus seems that basic elements required in an effective educator-student relationship to strengthen the resilience of students include the environment, interaction, educator and student's qualities and resilience.


No association between use of multivitamin supplement containing vitamin D during pregnancy and risk of Type 1 Diabetes in the child.
Sweden has the second highest incidence of type 1 diabetes in the world. Nutritional aspects in utero and in infancy affect the development. We conducted a survey to determine whether reported maternal use of vitamin D-containing micronutrient supplements during pregnancy was associated with the risk of developing type 1 diabetes in the child. This report was based on data from the ABIS (All Babies In Southeast Sweden) study, with questionnaire data on 16 339 mother and infant pairs at birth and at 1-yr of age (n = 10 879), of whom 108 children were registered with type 1 diabetes before 14-16 yr of age. The questions 'during pregnancy, did you take any vitamin/mineral supplements?' and 'if yes, which? (open answer)' in addition to other lifestyle questions were answered. Logistic regression was performed with onset of type 1 diabetes as the dependent variable and vitamin D supplementation use as the independent variable, adjusted for relevant factors. Vitamin D supplementation during pregnancy was consumed by 9.3% of mothers whose children later got type1 diabetes and among 11.3% of those mothers whose children did not get type 1 diabetes (p = 0.532). No significant association was found between reported supplement intake of vitamin D during pregnancy and risk of type 1 diabetes, even when adjusting for factors which could influence the association. Maternal use of vitamin D-containing multivitamin supplements during pregnancy was not related to the risk of developing type 1 diabetes in children before 14-16 yr of age in Southeast of Sweden.


HUWE1 E3 ligase promotes PINK1/PARKIN-independent mitophagy by regulating AMBRA1 activation via IKKα.
The selective removal of undesired or damaged mitochondria by autophagy, known as mitophagy, is crucial for cellular homoeostasis, and prevents tumour diffusion, neurodegeneration and ageing. The pro-autophagic molecule AMBRA1 (autophagy/beclin-1 regulator-1) has been defined as a novel regulator of mitophagy in both PINK1/PARKIN-dependent and -independent systems. Here, we identified the E3 ubiquitin ligase HUWE1 as a key inducing factor in AMBRA1-mediated mitophagy, a process that takes place independently of the main mitophagy receptors. Furthermore, we show that mitophagy function of AMBRA1 is post-translationally controlled, upon HUWE1 activity, by a positive phosphorylation on its serine 1014. This modification is mediated by the IKKα kinase and induces structural changes in AMBRA1, thus promoting its interaction with LC3/GABARAP (mATG8) proteins and its mitophagic activity. Altogether, these results demonstrate that AMBRA1 regulates mitophagy through a novel pathway, in which HUWE1 and IKKα are key factors, shedding new lights on the regulation of mitochondrial quality control and homoeostasis in mammalian cells.


Calorimetric unfolding of intramolecular triplexes: length dependence and incorporation of single AT --> TA substitutions in the duplex domain.
DNA triplexes have been the subject of great interest due to their ability to interfere with gene expression. The inhibition of gene expression involves the design of stable triplexes under physiological conditions; therefore, it is important to have a clear understanding of the energetic contributions controlling their stability. We have used a combination of UV spectroscopy and differential scanning calorimetric (DSC) techniques to investigate the unfolding of intramolecular triplexes, d(A(n)C5T(n)C5T(n)), where n is 5-7, 9, and 11, and related triplexes with a single AT --> TA substitution in their duplex stem. Specifically, we obtain standard thermodynamic profiles for the unfolding of each triplex in buffer solutions containing 0.1 M or 1 M NaCl. The triplexes unfold in monophasic or biphasic transitions (triplex --> duplex --> coil) depending on the concentration of salt used and position of the substitution, and their transition temperatures are independent of strand concentration. The DSC curves of the unsubstituted triplexes yielded an unfolding heat of 13.9 kcal/mol for a TAT/TAT base-triplet stack and a heat capacity of 505 cal/ degrees C.mol. The incorporation of a single substitution destabilizes triplex formation (association of the third strand) to a larger extent in 0.1 M NaCl, and the magnitude of the effects also depends on the position of the substitution. The combined results show that a single AT --> TA substitution in a homopurine/homopyrimidine duplex does not allow triplex formation of the neighboring five TAT base triplets, indicating that the in vivo formation of triplexes, such as H-DNA, is exclusive to homopurine/homopyrimidine sequences.


Remote infrared signage evaluation for transit stations and intersections.
Opportunities for education and employment depend upon effective and independent travel. For mainstream society, this is accomplished to a large extent by printed signs. People who are print disabled, visually impaired, or totally blind are at a disadvantage because they do not have access to signage. Remote infrared signage, such as the Talking Signs (TS) system, provides a solution to this need by labeling the environment for distant viewing. The system uses a transmitting "sign" and a hand-held receiver to tell people about their surroundings. In a seamless infrared signage environment, a visually impaired traveler could: walk safely across an intersection to an ATM or fare machine, from fare machine to bus stop, from bus stop to bus; from bus to building, from building to elevator, from elevator to office, from office to restroom, and so forth. This paper focuses on two problems that are among the most challenging and dangerous faced by blind travelers: negotiating complex transit stations and controlled intersections. We report on human factors studies of TS in these critical tasks, examining such issues as how much training is needed to use the system, its impact on performance and safety, benefits for different population subgroups and user opinions of its value. Results indicate that blind people can quickly and easily learn to use remote infrared signage effectively, and that its use improves travel safety, efficiency, and independence.


Supraspinal fatigue is similar in men and women for a low-force fatiguing contraction.
This study determined the contribution of supraspinal fatigue to the sex difference in neuromuscular fatigue for a low-intensity fatiguing contraction. Because women have greater motor responses to arousal than men, we also examined whether cortical and motor nerve stimulation, techniques used to quantify central fatigue, would alter the sex difference in muscle fatigue. In study 1, cortical stimulation was elicited during maximal voluntary contractions (MVC) before and after a submaximal isometric contraction at 20% MVC with the elbow flexor muscles in 29 young adults (20 ± 2.6 yr, 14 men). In study 2, 10 men and 10 women (19.1 ± 2.9 yr) performed a fatiguing contraction in the presence and absence of cortical and motor nerve stimulation. Study 1: Men had a briefer time to task failure than women (P = 0.009). Voluntary activation was reduced after the fatiguing contraction (P < 0.001) similarly for men and women. Motor-evoked potential area and the EMG silent period increased similarly with fatigue for both sexes. Peak relaxation rates, however, were greater for men than women and were associated with time to task failure (P < 0.05). Force fluctuations, RPE, HR, and mean arterial pressure increased at a greater rate for men than for women during the fatiguing contraction (P < 0.05). Study 2: Time to task failure, force fluctuations, and all other physiological variables assessed were similar for the control session and stimulation session (P > 0.05) for both men and women. Supraspinal fatigue was similar for men and women after the low-force fatiguing contraction, and the sex difference in muscle fatigue was associated with peripheral mechanisms. Furthermore, supraspinal fatigue can be quantified in both men and women without influencing motor performance.


Nonlinear dynamic causal models for fMRI.
Models of effective connectivity characterize the influence that neuronal populations exert over each other. Additionally, some approaches, for example Dynamic Causal Modelling (DCM) and variants of Structural Equation Modelling, describe how effective connectivity is modulated by experimental manipulations. Mathematically, both are based on bilinear equations, where the bilinear term models the effect of experimental manipulations on neuronal interactions. The bilinear framework, however, precludes an important aspect of neuronal interactions that has been established with invasive electrophysiological recording studies; i.e., how the connection between two neuronal units is enabled or gated by activity in other units. These gating processes are critical for controlling the gain of neuronal populations and are mediated through interactions between synaptic inputs (e.g. by means of voltage-sensitive ion channels). They represent a key mechanism for various neurobiological processes, including top-down (e.g. attentional) modulation, learning and neuromodulation. This paper presents a nonlinear extension of DCM that models such processes (to second order) at the neuronal population level. In this way, the modulation of network interactions can be assigned to an explicit neuronal population. We present simulations and empirical results that demonstrate the validity and usefulness of this model. Analyses of synthetic data showed that nonlinear and bilinear mechanisms can be distinguished by our extended DCM. When applying the model to empirical fMRI data from a blocked attention to motion paradigm, we found that attention-induced increases in V5 responses could be best explained as a gating of the V1-->V5 connection by activity in posterior parietal cortex. Furthermore, we analysed fMRI data from an event-related binocular rivalry paradigm and found that interactions amongst percept-selective visual areas were modulated by activity in the middle frontal gyrus. In both practical examples, Bayesian model selection favoured the nonlinear models over corresponding bilinear ones.


Synthesis of four novel trisaccharides by induction of loose acceptor specificity in Gal beta 1----4 transferase (EC 22.214.171.124): Galp(beta 1----4)Glcp(X)Glc where X = beta 1----3: beta 1----4: beta 1----6: alpha 1----4.
Development of tandem mass spectral methods for direct linkage determination in oligosaccharides requires sets of trisaccharides differing only in one structural parameter. In this case, we chose the position of linkage to the reducing-end hexose. These sets of compounds would also be useful for the development of high-resolution separation techniques geared to resolve linkage types. Conventional organic synthesis of such a set could take as long as 2-5 months for each member of the set. Each trisaccharide would require 10-20 steps of synthesis. Instead, we utilized low pH to induce a loose acceptor specificity for bovine milk galactosyltransferase (lactose synthase: EC 188.8.131.52) and by this method, within 2 weeks, generated four novel oligosaccharides for NMR and mass spectral studies. The disaccharides cellobiose (beta 1----4), laminaribiose (beta 1----3), gentiobiose (beta 1----6) and maltose (alpha 1----4) acted as acceptors for EC 184.108.40.206 under these conditions. The beta 1----2-linked disaccharide, sophorose, was not commercially available and is not included in this study. The alpha-linked disaccharides were also examined, but except for the alpha 1----4 disaccharide maltose, were very poor acceptors under a variety of conditions. From these four acceptors, the following four novel trisaccharides were synthesized in micromole amounts, suitable for studies of linkage position using low-energy collision-induced-dissociation tandem mass spectrometry (FAB-MS-CID-MS), and for NMR: Galp(beta 1----4)Glcp(beta 1----3)-Glc, Galp(beta 1----4)Glcp(beta 1----4)Glc, Galp(beta 1----4)Glcp(beta 1----6)-Glc and Galp(beta 1----4)Glcp(alpha 1----4)Glc.