Cell membrane integrity and internalization of ingested TiO(2) nanoparticles by digestive gland cells of a terrestrial isopod.
The present study was motivated by the paucity of reports on cellular internalization of ingested titanium dioxide (TiO(2)) nanoparticles (nano-TiO(2)). The model invertebrate (Porcellio scaber, Isopoda, Crustacea) was exposed to food dosed with nano-TiO(2) containing 100, 1,000, 3,000, or 5,000 µg nano-TiO(2) per gram of food. After 14 d of exposure, the amount of Ti in the entire body was analyzed by inductively coupled plasma-mass spectrometry, and elemental analyses of tissue cross sections were performed by particle induced X-ray emission. In addition, a series of toxicological markers including feeding parameters, weight change, and survival, as well as cytotoxic effects such as digestive gland cell membrane stability, were monitored. Internalization of ingested nano-TiO(2) by the isopod's digestive gland epithelial cells was shown to depend on cell membrane integrity. Cell membranes were found to be destabilized by TiO(2) particles, and at higher extracellular concentrations of nano-TiO(2), the nanoparticles were internalized.


Exposure to workplace violence and threats and risk of depression: a prospective study.
Several studies have examined the health consequences of workplace threats and violence, however, due to methodological issues the epidemiological evidence is limited. The purpose of this study was to examine the prospective association between self-labelled exposure to work-related threats and violence and the risk of depression, measured by a standardized psychiatric interview and new prescriptions of anti-depressive medication. Employees were recruited from the Danish PRISME cohort established in 2007 where 4489 Danish public employees answered a postal questionnaire with follow-ups in 2009 and 2011. In all three waves, depression was diagnosed by clinical interviews with the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). In addition, we ascertained prescription of anti-depressive medication from a national register. Using logistic regression and Cox proportional hazard models, we estimated the association between exposure to threats and violence at baseline and SCAN depression and prescription of anti-depressive medication during two years of follow-up. Self-labelled exposure to work-related threats and violence was associated with a risk of SCAN diagnosed depression two years later, odds ratios (OR) 2.20 [95% confidence interval (CI) 1.13-4.28] and OR 2.11 (95% CI 1.05-4.24), respectively, with indication of a dose-response. Self-labelled exposure to work-related threats and violence was associated with prescription of anti-depressive medication in a two-year period, hazard ratios (HR) 2.55 (95% CI 1.47-4.40) and HR 1.47 (95% CI 0.70-3.06), respectively. Exposure to work-related threats or violence is associated with an increased risk of depression two years later, measured with a psychiatric interview and register data on prescribed antidepressants.


Drugs for nocturnal enuresis in children (other than desmopressin and tricyclics).
Enuresis (bedwetting) is a socially stigmatising and stressful condition which affects around 15% to 20% of five-year olds and up to 2% of young adults. Although there is a high rate of spontaneous remission, the social, emotional and psychological costs to the children can be great. Drugs (including desmopressin, tricyclics and other drugs) have often been tried to treat nocturnal enuresis. To assess the effects of drugs other than desmopressin and tricyclics on nocturnal enuresis in children and to compare them with other interventions. We searched the Cochrane Incontinence Group Specialised Register of trials (searched 15 December 2011), which includes searches of MEDLINE and CENTRAL, to identify published and unpublished randomised and quasi-randomised trials. The reference lists of relevant articles were also searched. All randomised trials of drugs (excluding desmopressin or tricyclics) for treating nocturnal enuresis in children up to the age of 16 years were included in the review. Trials were eligible for inclusion if children were randomised to receive drugs compared with placebo, other drugs or behavioral interventions for nocturnal enuresis. Studies which included children with daytime urinary incontinence or children with organic conditions were also included in this review if the focus of the study was on nocturnal enuresis. Trials focused solely on daytime wetting and trials of adults with nocturnal enuresis were excluded. Two review authors independently assessed the quality of the eligible trials and extracted data. Differences between review authors were settled by discussion with a third review author. A total of 40 randomised or quasi-randomised controlled trials (10 new in this update) met the inclusion criteria, with a total of 1780 out of 2440 children who enrolled receiving an active drug other than desmopressin or a tricyclic. In all, 31 different drugs or classes of drugs were tested. The trials were generally small or of poor methodological quality. There was an overall paucity of data regarding outcomes after treatment was withdrawn.For drugs versus placebo, when compared to placebo indomethacin (risk ratio [RR] 0.36, 95% CI 0.16 to 0.79), diazepam (RR 0.22, 95% CI 0.11 to 0.46), mestorelone (RR 0.32, 95% CI 0.17 to 0.62) and atomoxetine (RR 0.81, 95% CI 0.70 to 0.94) appeared to reduce the number of children failing to have 14 consecutive dry nights. Although indomethacin and diclofenac were better than placebo during treatment, they were not as effective as desmopressin and there was a higher chance of adverse effects. None of the medications were effective in reducing relapse rates, although this was only reported in five placebo controlled trials.For drugs versus drugs, combination therapy with imipramine and oxybutynin was more effective than imipramine monotherapy (RR 0.68, 95% CI 0.50 to 0.94) and also had significantly lower relapse rates than imipramine monotherapy (RR 0.35, 95% CI 0.16 to 0.77). There was an overall paucity of data regarding outcomes after treatment was withdrawn.For drugs versus behavioural therapy, bedwetting alarms were found to be better than amphetamine (RR 2.2, 95% CI 1.12 to 4.29), oxybutynin (RR 3.25, 95% CI 1.77 to 5.98), and oxybutynin plus holding exercises (RR 3.3, 95% CI 1.84 to 6.18) in reducing the number of children failing to achieve 14 consecutive dry nights.Adverse effects of drugs were seen in 19 trials while 17 trials did not adequately report the occurrence of side effects. There was not enough evidence to judge whether or not the included drugs cured bedwetting when used alone. There was limited evidence to suggest that desmopressin, imipramine and enuresis alarms therapy were better than the included drugs to which they were compared. In other reviews, desmopressin, tricyclics and alarm interventions have been shown to be effective during treatment. There was also evidence to suggest that combination therapy with anticholinergic therapy increased the efficacy of other established therapies such as imipramine, desmopressin and enuresis alarms by reducing the relapse rates, by about 20%, although it was not possible to identify the characteristics of children who would benefit from combination therapy. Future studies should evaluate the role of combination therapy against established treatments in rigorous and adequately powered trials.


Human mesenchymal stem cells exert potent antitumorigenic effects in a model of Kaposi's sarcoma.
Emerging evidence suggests that both human stem cells and mature stromal cells can play an important role in the development and growth of human malignancies. In contrast to these tumor-promoting properties, we observed that in an in vivo model of Kaposi's sarcoma (KS), intravenously (i.v.) injected human mesenchymal stem cells (MSCs) home to sites of tumorigenesis and potently inhibit tumor growth. We further show that human MSCs can inhibit the in vitro activation of the Akt protein kinase within some but not all tumor and primary cell lines. The inhibition of Akt activity requires the MSCs to make direct cell-cell contact and can be inhibited by a neutralizing antibody against E-cadherin. We further demonstrate that in vivo, Akt activation within KS cells is potently down-regulated in areas adjacent to MSC infiltration. Finally, the in vivo tumor-suppressive effects of MSCs correlates with their ability to inhibit target cell Akt activity, and KS tumors engineered to express a constitutively activated Akt construct are no longer sensitive to i.v. MSC administration. These results suggest that in contrast to other stem cells or normal stromal cells, MSCs possess intrinsic antineoplastic properties and that this stem cell population might be of particular utility for treating those human malignancies characterized by dysregulated Akt.


Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012.
Estimates of the worldwide incidence and mortality from 27 major cancers and for all cancers combined for 2012 are now available in the GLOBOCAN series of the International Agency for Research on Cancer. We review the sources and methods used in compiling the national cancer incidence and mortality estimates, and briefly describe the key results by cancer site and in 20 large "areas" of the world. Overall, there were 14.1 million new cases and 8.2 million deaths in 2012. The most commonly diagnosed cancers were lung (1.82 million), breast (1.67 million), and colorectal (1.36 million); the most common causes of cancer death were lung cancer (1.6 million deaths), liver cancer (745,000 deaths), and stomach cancer (723,000 deaths).


Loss of the Par3 polarity protein promotes breast tumorigenesis and metastasis.
Loss of epithelial organization is a hallmark of carcinomas, but whether polarity regulates tumor growth and metastasis is poorly understood. To address this issue, we depleted the Par3 polarity gene by RNAi in combination with oncogenic Notch or Ras(61L) expression in the murine mammary gland. Par3 silencing dramatically reduced tumor latency in both models and produced invasive and metastatic tumors that retained epithelial marker expression. Par3 depletion was associated with induction of MMP9, destruction of the extracellular matrix, and invasion, all mediated by atypical PKC-dependant JAK/Stat3 activation. Importantly, Par3 expression is significantly reduced in human breast cancers, which correlates with active aPKC and Stat3. These data identify Par3 as a regulator of signaling pathways relevant to invasive breast cancer.


Management of Thrombocytopenia in Chronic Liver Disease: Focus on Pharmacotherapeutic Strategies.
Thrombocytopenia (platelet count <150 × 10(9)/L) often complicates chronic liver disease, impeding optimal management of these patients. The prevalence of this manifestation ranges from 6% among non-cirrhotic patients with chronic liver disease to 70% among patients with liver cirrhosis. It has also been shown that the severity of liver disease is associated with both prevalence and level of thrombocytopenia. Its development is often multifactorial, although thrombopoietin is thought to be a major factor. The discovery of and ability to clone thrombopoietin led to new treatment opportunities for this clinical manifestation. This review discusses data on the three most important thrombopoietin receptor agonists: eltrombopag, avatrombopag, and romiplostim. Currently, only eltrombopag is approved for usage among patients with thrombocytopenia and chronic hepatitis C virus infection in order to initiate and maintain interferon-based antiviral treatment. Nevertheless, the optimal management of hematologic abnormalities among patients with chronic liver disease, and its risk for bleeding complications, is still a matter of discussion. Thrombocytopenia definitely contributes to hemostatic defects but is often counterbalanced by the enhanced presence of procoagulant factors. Therefore, a thorough assessment of the patient's risk for thrombotic events is essential when the use of thrombopoietin receptor agonists is considered among patients with chronic liver disease and thrombocytopenia.


Association of variants in DRD2 and GRM3 with motor and cognitive function in first-episode psychosis.
Similar smooth pursuit eye tracking dysfunctions are present across psychotic disorders. They include pursuit initiation and maintenance deficits that implicate different functional brain systems. This candidate gene study examined psychosis-related genotypes regulating dopamine and glutamate neurotransmission in relation to these pursuit deficits. One hundred and thirty-eight untreated first-episode patients with a psychotic disorder were genotyped for four markers in DRD2 and four markers in GRM3. The magnitude of eye movement abnormality in patients was defined in relation to performance of matched healthy controls (N = 130). Eighty three patients were followed after 6 weeks of antipsychotic treatment. At baseline, patients with a -141C deletion in DRD2 rs1799732 had slower initiation eye velocity and longer pursuit latency than CC insertion carriers. Further, GRM3 rs274622_CC carriers had poorer pursuit maintenance than T-carriers. Antipsychotic treatment resulted in prolonged pursuit latency in DRD2 rs1799732_CC insertion carriers and a decline in pursuit maintenance in GRM3 rs6465084_GG carriers. The present study demonstrates for the first time that neurophysiological measures of motor and neurocognitive deficits in patients with psychotic disorders have different associations with genes regulating dopamine and glutamate systems, respectively. Alterations in striatal D2 receptor activity through the -141C Ins/Del polymorphism could contribute to pursuit initiation deficits in psychotic disorders. Alterations in GRM3 coding for the mGluR3 protein may impair pursuit maintenance by compromising higher perceptual and cognitive processes that depend on optimal glutamate signaling in corticocortical circuits. DRD2 and GRM3 genotypes also selectively modulated the severity of adverse motor and neurocognitive changes resulting from antipsychotic treatment.


Deciphering the somite segmentation clock: beyond mutants and morphants.
The regular pattern of somite segmentation depends on a clock, the somite segmentation clock, in the form of a gene expression oscillator, operating in the presomitic mesoderm (the PSM) at the tail end of the vertebrate embryo. Genetic screens and other approaches have identified a variety of genes, including components and targets of the Notch signalling pathway, that show transcriptional oscillations in this region and appear to be necessary for correct segmentation. Mathematical modelling shows that the oscillations could plausibly be generated by a simple mechanism of delayed negative feedback, based on autoinhibition of Notch target genes of the Hes/her family by their own protein products. To move beyond plausible models to an experimentally validated theory, however, it is necessary to measure the parameters on which the proposed model is based and to devise ways of probing the dynamics of the system by means of timed disturbances so as to compare with the model's predictions. Some progress is being made in these directions.


Transmission of Pneumocystis carinii from patients to hospital staff.
An extrahuman reservoir of human pathogenic Pneumocystis carinii remains unknown. Host to host transmission has been described in animal studies and in cluster cases among immunodeficient patients. P carinii DNA has recently been detected in air filters from inpatient and outpatient rooms in departments of infectious diseases managing patients with P carinii pneumonia (PCP), suggesting the airborne route of transmission. Exposure of staff to P carinii may occur in hospital departments treating patients with PCP. Exposure to P carinii was detected by serological responses to human P carinii by ELISA, Western blotting, and indirect immunofluorescence in 64 hospital staff with and 79 staff without exposure to patients with PCP from Denmark and Sweden. DNA amplification of oropharyngeal washings was performed on 20 Danish staff with and 20 staff without exposure to patients with PCP. There was no significant difference in the frequency or level of antibodies to P carinii between staff exposed and those unexposed to patients with PCP. None of the hospital staff had detectable P carinii DNA in oropharyngeal washings. There is no difference in antibodies and no detectable P carinii DNA in oropharyngeal washings, which suggests that immunocompetent staff treating patients with PCP are not a potentially infectious source of P carinii for immunocompromised patients.


Name relearning in elderly patients with schizophrenia: episodic and temporary, not semantic and permanent.
Recent reports of lexical-semantic deficits in patients with schizophrenia (Laws, Al-Uzri, & Mortimer, 2000; Laws, McKenna, & Kondel, 1998) suggest that younger patients have problems accessing intact memories and older patients show apparent "loss" of the lexical-semantic memory representations themselves. Picture naming for everyday items was examined in a unique series of elderly patients with schizophrenia (n = 10) with a mean illness duration of 45.5 years; and compared with that in patients with probable Alzheimer's disease (n = 18) and elderly healthy controls (n = 27). Naming consistency across time was used as an indicator of whether the schizophrenic patients had difficulty accessing representations or a loss of the representations themselves. Finally, we examined the ability of the schizophrenic patients to relearn the names of unnamed items across four weekly retraining sessions and to retain them at a one month follow-up. The elderly schizophrenic patients were as anomic as patients with probable Alzheimer's disease. Consistency analysis revealed that the patients had storage deficits. Analysis of patient error types was consistent with a semantic deficit. Finally, the schizophrenic patients showed significant improvement with relearning, but this was not maintained at follow-up. Elderly patients with schizophrenia show a profound and stable anomia. Although name relearning induced some significant gains in naming, these were short-term and reflect episodic rather than semantic reinstatement of representations. Implications for cognitive remediation are discussed.


Transcriptional response of the bovine endometrium and embryo to endometrial polymorphonuclear neutrophil infiltration as an indicator of subclinical inflammation of the uterine environment.
The aim of the present study was to analyse the effect of subclinical endometritis on endometrial and embryonic gene expression. A total of 49 cows at either Day 0 or Day 7 of the oestrous cycle (62-83 days post partum) following superovulation were classified as having subclinical endometritis (SE-0, SE-7) or a healthy endometrium (HE-0, HE-7) on the basis of endometrial cytological evaluation. Endometrial samples and associated embryos were subjected to global transcriptome analysis using the Bovine GeneChip (Affymetrix, Santa Clara, CA, USA) and aberrant transcript profiles were observed in SE-0 and SE-7 cows. At Day 0, 10 transcripts were found to be differentially expressed in endometrial samples. Specifically, the PDZK1, PXDN, DDHD2, GPLD1 and SULT1B1 genes were downregulated, whereas the PKIB, LOC534256, BT29392, LYZ and S100A14 genes were upregulated in SE-0 cows. Similarly, 11 transcripts were found to be differentially regulated on Day 7. Of these, GNPTG, BOLA-DQA5, CHD2, LOC541226, VCAM1 and ARHGEF2 were found to be downregulated, whereas PSTPIP2, BT236441 and MGC166084 were upregulated in SE-7 cows. Accordingly, endometrial health status affected the number of flushed, transferable embryos. In all, 20 genes were differentially regulated in blastocysts derived from HE-7 and SE-7 cows. Of these, GZMK, TCEAL4, MYL7, ADD3 and THEM50B were upregulated, whereas NUDCD2, MYO1E, BZW1, EHD4 and GZMB were downregulated. In conclusion, endometrial polymorphonuclear neutrophil infiltration as an indicator of subclinical endometritis is associated with changes in endometrial gene expression patterns, including genes involved in cell adhesion and immune modulation. Consequently, subclinical endometritis affects gene expression in embryos, including the expression of genes related to membrane stability, the cell cycle and apoptosis.


"If I have a cancer, it is not my fault I am a refugee": A qualitative study with expert stakeholders on cancer care management for Syrian refugees in Jordan.
Noncommunicable diseases including cancer are widespread amongst the 5.6 million Syrian refugees currently hosted in the Middle East. Given its prevalence as the third leading cause of death in Syria, cancer is likely to be an important health burden among Syrian refugees. Against this background, our aim was to describe the clinical, ethical and policy decision-making experiences of health actors working within the current refugee cancer care system; the impact of refugee cancer care health policies on health care providers and policy makers in this context; and provide suggestions for the way delivery of care should be optimised in a sustained emergency situation. From April-July 2016, we conducted in-depth interviews with 12 purposively sampled health officials and health care workers from the Jordanian Ministry of Health, multilateral donors and international non-governmental organisations. Data were analysed using a framework analysis approach to identify systemic, practical and ethical challenges to optimising care for refugees, through author agreement on issues emerging from the data and those linked more directly to areas of questioning. As has been previously reported, central challenges for policy makers and health providers were the lack of quality cancer prevalence data to inform programming and care delivery for this refugee population, and insufficient health resource allocation to support services. In addition, limited access to international funding for the host country, the absence of long-term funding schemes, and barriers to coordination between institutions and frontline clinicians were seen as key barriers. In this context where economic priorities inevitably drive decision-making on public health policy and individual care provision, frontline healthcare workers and policy makers experienced significant moral distress where duties of care and humanitarian values were often impossible to uphold. Our findings confirm and expand understanding of the challenges involved in resource allocation decisions for cancer care in refugee populations, and highlight these for the particular situation of long term Syrian refugees in Jordan. The insights offered by frontline clinicians and policy makers in this context reveal the unintended personal and moral impact of resource allocation decisions. With many countries facing similar challenges in the provision of cancer care for refugees, the lessons learned from Jordan suggest key areas for policy revision and international investment in developing cancer care policies for refugees internationally.


Using evidence in the development of local health policies. Some evidence from the United Kingdom.
This paper explores the use of evidence, focusing on economic evidence in particular, in the development of local health policies through an in-depth study of Health Improvement Programmes (HImPs) in England. A questionnaire was sent to the person responsible for coordinating the development of the HImP in each of the 102 English health authorities. In addition, semi-structured interviews were conducted with 10 HImP leaders, and a random sample of 26 HImP documents was reviewed using a standard pro forma. Of the 102 mail questionnaires sent out, 68 (67%) were returned. It was found that those developing HImPs had multiple objectives, only some of which (e.g., efficiency in healthcare provision) would necessarily require evidence. Where evidence was used, this was a mixture of internal (experiential) and external (empirical) evidence, with the balance (66%) being in favor of the latter. Government reports and guidance from the National Institute for Clinical Excellence (NICE), were the main sources of external evidence, rather than published papers. Key barriers to the use of economic evidence were lack of time and availability and the difficulties in synthesizing information at the local level. Based on responses to our survey, the main ways of increasing the use of evidence in the development of local health policies in England are to produce more evidence-based national guidance and to produce accessible summaries of the available literature for local decision makers.


Vibrationally induced metallisation of the energetic azide α-NaN3.
As initiation of an energetic material requires rupture of a covalent bond, and therefore population of antibonding electronic states, consideration of the electronic band gap has dominated initiation mechanisms for solid state materials. Most prominent are models based on metallisation, where static mechanical perturbation leads to closing of the electronic band gap. This work explores an alternative mechanism for the dynamic metallisation of a model energetic material, where vibrational excitation resulting from mechanical impact is found to induce transient metallisation of α-NaN3. The normal coordinates associated with bending the azido anion close the electronic band gap, facilitating the formation of highly reactive species important for initiation of energetic materials. The DFT simulated vibrational spectrum of α-NaN3 exhibits excellent reproduction of the experimental low-temperature inelastic neutron scattering spectrum (INS).


MEG-BMI to Control Phantom Limb Pain.
A brachial plexus root avulsion (BPRA) causes intractable pain in the insensible affected hands. Such pain is partly due to phantom limb pain, which is neuropathic pain occurring after the amputation of a limb and partial or complete deafferentation. Previous studies suggested that the pain was attributable to maladaptive plasticity of the sensorimotor cortex. However, there is little evidence to demonstrate the causal links between the pain and the cortical representation, and how much cortical factors affect the pain. Here, we applied lesioning of the dorsal root entry zone (DREZotomy) and training with a brain-machine interface (BMI) based on real-time magnetoencephalography signals to reconstruct affected hand movements with a robotic hand. The DREZotomy successfully reduced the shooting pain after BPRA, but a part of the pain remained. The BMI training successfully induced some plastic changes in the sensorimotor representation of the phantom hand movements and helped control the remaining pain. When the patient tried to control the robotic hand by moving their phantom hand through association with the representation of the intact hand, this especially decreased the pain while decreasing the classification accuracy of the phantom hand movements. These results strongly suggested that pain after the BPRA was partly attributable to cortical representation of phantom hand movements and that the BMI training controlled the pain by inducing appropriate cortical reorganization. For the treatment of chronic pain, we need to know how to modulate the cortical representation by novel methods.


A graphic user interface toolkit for specification, report and comparison of dose-response relations and treatment plans using the biologically effective uniform dose.
A toolkit (BEUDcal) has been developed for evaluating the effectiveness and for predicting the outcome of treatment plans by calculating the biologically effective uniform dose (BEUD) and complication-free tumor control probability. The input for the BEUDcal is the differential dose-volume histograms of organs exported from the treatment planning system. A clinical database is built for the dose-response parameters of different tumors and normal tissues. Dose-response probabilities of all the examined organs are illustrated together with the corresponding BEUDs and the P(+) values. Furthermore, BEUDcal is able to generate a report that simultaneously presents the radiobiological evaluation together with the physical dose indices, showing the complementary relation between the physical and radiobiological treatment plan analysis performed by BEUDcal. Comparisons between treatment plans for helical tomotherapy and multileaf collimator-based intensity modulated radiotherapy of a lung patient were demonstrated to show the versatility of BEUDcal in the assessment and report of dose-response relations.


Toxoplasma gondii infection, from predation to schizophrenia: can animal behaviour help us understand human behaviour?
We examine the role of the protozoan Toxoplasma gondii as a manipulatory parasite and question what role study of infections in its natural intermediate rodent hosts and other secondary hosts, including humans, may elucidate in terms of the epidemiology, evolution and clinical applications of infection. In particular, we focus on the potential association between T. gondii and schizophrenia. We introduce the novel term 'T. gondii-rat manipulation-schizophrenia model' and propose how future behavioural research on this model should be performed from a biological, clinical and ethically appropriate perspective.


Identification of growing bacteria during litter decomposition in freshwater through H218O quantitative stable isotope probing.
Identification of microorganisms that facilitate the cycling of nutrients in freshwater is paramount to understanding how these ecosystems function. Here, we identify growing aquatic bacteria using H218O quantitative stable isotope probing. During 8 day incubations in 97 atom % H218O, 54% of the taxa grew. The most abundant phyla among growing taxa were Proteobacteria (45%), Bacteroidetes (30%) and Firmicutes (10%). Taxa differed in isotopic enrichment, reflecting variation in DNA replication of bacterial populations. At the class level, the highest atom fraction excess was observed for OPB41 and δ-Proteobacteria. There was no linear relationship between 18 O incorporation and abundance of taxa. δ-Proteobacteria and OPB41 were not abundant, yet the DNA of both taxa was highly enriched in 18 O. Bacteriodetes, in contrast, were abundant but not highly enriched. Our study shows that a large proportion of the bacterial taxa found on decomposing leaf litter grew slowly, and several low abundance taxa were highly enriched. These findings indicating that rare organisms may be important for the decomposition of leaf litter in streams, and that quantitative stable isotope probing with H218O can be used to advance our understanding of microorganisms in freshwater by identifying species that are growing in complex communities.


Stimulus-induced S-nitrosylation of Syntaxin 4 impacts insulin granule exocytosis.
Glucose-stimulated insulin release from pancreatic islet β-cells involves increased levels of reactive oxygen and nitrogen species. Although this is normal, under pathophysiological conditions such as chronic hyperglycemia and inflammation, insulin exocytosis fails, and yet the mechanistic reason for failure is unclear. Hypothesizing that exocytotic proteins might be targets of S-nitrosylation, with their dysfunction under conditions of nitrosative stress serving as a mechanistic basis for insulin secretory dysfunction, we identified the t-SNARE protein Syntaxin 4 as a target of modification by S-nitrosylation. The cellular content of S-nitrosylated Syntaxin 4 peaked acutely, within 5 min of glucose stimulation in both human islets and MIN6 β-cells, corresponding to the time at which Syntaxin 4 activation was detectable. S-Nitrosylation was mapped to Syntaxin 4 residue Cys(141), located within the Hc domain predicted to increase accessibility for v-SNARE interaction. A C141S-Syntaxin 4 mutant resisted S-nitrosylation induced in vitro by the nitric oxide donor compound S-nitroso-L-glutathione, failed to exhibit glucose-induced activation and VAMP2 binding, and failed to potentiate insulin release akin to that of wild-type Syntaxin 4. Strikingly, S-nitrosylation of Syntaxin 4 could be induced by acute treatment with inflammatory cytokines (TNFα, IL-1β, and IFNγ), coordinate with inappropriate Syntaxin 4 activation and insulin release in the absence of the glucose stimulus, consistent with nitrosative stress and dysfunctional exocytosis, preceding the cell dysfunction and death associated with more chronic stimulation (24 h). Taken together, these data indicate a significant role for reactive nitrogen species in the insulin exocytosis mechanism in β-cells and expose a potential pathophysiological exploitation of this mechanism to underlie dysfunctional exocytosis.


The association between perceived discrimination and obesity in a population-based multiracial and multiethnic adult sample.
We examined whether perceived chronic discrimination was related to excess body fat accumulation in a random, multiethnic, population-based sample of US adults. We used multivariate multinomial logistic regression and logistic regression analyses to examine the relationship between interpersonal experiences of perceived chronic discrimination and body mass index and high-risk waist circumference. Consistent with other studies, our analyses showed that perceived unfair treatment was associated with increased abdominal obesity. Compared with Irish, Jewish, Polish, and Italian Whites who did not experience perceived chronic discrimination, Irish, Jewish, Polish, and Italian Whites who perceived chronic discrimination were 2 to 6 times more likely to have a high-risk waist circumference. No significant relationship between perceived discrimination and the obesity measures was found among the other Whites, Blacks, or Hispanics. These findings are not completely unsupported. White ethnic groups including Polish, Italians, Jews, and Irish have historically been discriminated against in the United States, and other recent research suggests that they experience higher levels of perceived discrimination than do other Whites and that these experiences adversely affect their health.


Evaluation of adverse drug reactions in HIV positive patients in a tertiary care hospital.
The advancement and development of new drugs and treatment strategies increase the risk of unusual Adverse Events (AEs) in HIV patients. The objective of our study was to assess the incidence, types and nature of AEs in HIV positive subjects. Patients with WHO stage IV disease irrespective of the CD4 cell count, or WHO stage III disease with a CD4 cell count <350 cell/cu. Mm, or, WHO stage I or II disease with a CD4 cell count of <200 cells/cu. mm, and on prior anti-retroviral therapy for not more than six months preceding the observation date, were included in the study. After initiation of therapy, the patients were examined for the occurrence any adverse events including the type and severity, or any other abnormal laboratory findings. Causality assessment of the adverse events was done using the Naranjo's scale. Out of 327 patients studied prospectively, 43 patients developed AEs. Out of these, 23 (53.5%) were males and 20 (46.5%) were females. A total of 53 (16.21%) AEs were reported. Antitubercular drugs caused the maximum AEs (28.3%) followed by zidovudine (20.7%), nevirapine (15.0%) and efavirenz (5.6%). Stavudine, ethambutol, sulfamethoxazole and trimethoprim, and atazanavir were also responsible for 3.7% of AEs individually. Causality assessment done according to the Naranjo's scale revealed that 66.04% AEs were 'probable' and 33.96% were 'possible'. Anemia, hepatitis and dermatological adverse effects are the most common AEs. Antitubercular drugs contributed significantly for the incidence of AEs in these patients. Frequency of AEs was slightly more in males compared to females.


An investigation of interactions between hypocretin/orexin signaling and glutamate receptor surface expression in the rat nucleus accumbens under basal conditions and after cocaine exposure.
Hypocretin peptides are critical for the effects of cocaine on excitatory synaptic strength in the ventral tegmental area (VTA). However, little is known about their role in cocaine-induced synaptic plasticity in the nucleus accumbens (NAc). First, we tested whether hypocretin-1 by itself could acutely modulate glutamate receptor surface expression in the NAc, given that hypocretin-1 in the VTA reproduces cocaine's effects on glutamate transmission. We found no effect of hypocretin-1 infusion on AMPA or NMDA receptor surface expression in the NAc, measured by biotinylation, either 30 min or 3h after the infusion. Second, we were interested in whether changes in hypocretin receptor-2 (Hcrtr-2) expression contribute to cocaine-induced plasticity in the NAc. As a first step towards addressing this question, Hcrtr-2 surface expression was compared in the NAc after withdrawal from extended-access self-administration of saline (control) versus cocaine. We found that surface Hcrtr-2 levels remain unchanged following 14, 25 or 48 days of withdrawal from cocaine, a time period in which high conductance GluA2-lacking AMPA receptors progressively emerge in the NAc. Overall, our results fail to support a role for hypocretins in acute modulation of glutamate receptor levels in the NAc or a role for altered Hcrtr-2 expression in withdrawal-dependent synaptic adaptations in the NAc following cocaine self-administration.


Close Contact Casting vs Surgery for Initial Treatment of Unstable Ankle Fractures in Older Adults: A Randomized Clinical Trial.
Ankle fractures cause substantial morbidity in older persons. Surgical fixation is the contemporary intervention but is associated with infection and other healing complications. To determine whether initial fracture treatment with close contact casting, a molded below-knee cast with minimal padding, offers outcome equivalent to that with immediate surgery, with fewer complications and less health resource use. This was a pragmatic, equivalence, randomized clinical trial with blinded outcome assessors. A pilot study commenced in May 2004, followed by multicenter recruitment from July 2010 to November 2013; follow-up was completed May 2014. Recruitment was from 24 UK major trauma centers and general hospitals. Participants were 620 adults older than 60 years with acute, overtly unstable ankle fracture. Exclusions were serious limb or concomitant disease or substantial cognitive impairment. Participants were randomly assigned to surgery (n = 309) or casting (n = 311). Casts were applied in the operating room under general or spinal anesthesia by a trained surgeon. The primary 6-month, per-protocol outcome was the Olerud-Molander Ankle Score at 6 months (OMAS; range, 0-100; higher scores indicate better outcomes and fewer symptoms), equivalence prespecified as ±6 points. Secondary outcomes were quality of life, pain, ankle motion, mobility, complications, health resource use, and patient satisfaction. Among 620 adults (mean age, 71 years; 460 [74%] women) who were randomized, 593 (96%) completed the study. Nearly all participants (579/620; 93%) received allocated treatment; 52 of 275 (19%) who initially received casting later converted to surgery, which was allowable in the casting treatment pathway to manage early loss of fracture reduction. At 6 months, casting resulted in ankle function equivalent to that with surgery (OMAS score, 66.0 [95% CI, 63.6-68.5] for surgery vs 64.5 [95% CI, 61.8-67.2] for casting; mean difference, -0.6 [95% CI, -3.9 to 2.6]; P for equivalence = .001). Infection and wound breakdown were more common with surgery (29/298 [10%] vs 4/275 [1%]; odds ratio [OR], 7.3 [95% CI, 2.6-20.2]), as were additional operating room procedures (18/298 [6%] for surgery and 3/275 [1%] for casting; OR, 5.8 [95% CI, 1.8-18.7]). Radiologic malunion was more common in the casting group (38/249 [15%] vs 8/274 [3%] for surgery; OR, 6.0 [95% CI, 2.8-12.9]). Casting required less operating room time compared with surgery (mean difference [minutes/participant], -54 [95% CI, -58 to -50]). There were no significant differences in other secondary outcomes: quality of life, pain, ankle motion, mobility, and patient satisfaction. Among older adults with unstable ankle fracture, the use of close contact casting compared with surgery resulted in similar functional outcomes at 6 months. Close contact casting may be an appropriate treatment for such patients. isrctn.com Identifier: ISRCTN04180738.


Low penetrance breast cancer susceptibility loci are associated with specific breast tumor subtypes: findings from the Breast Cancer Association Consortium.
Breast cancers demonstrate substantial biological, clinical and etiological heterogeneity. We investigated breast cancer risk associations of eight susceptibility loci identified in GWAS and two putative susceptibility loci in candidate genes in relation to specific breast tumor subtypes. Subtypes were defined by five markers (ER, PR, HER2, CK5/6, EGFR) and other pathological and clinical features. Analyses included up to 30 040 invasive breast cancer cases and 53 692 controls from 31 studies within the Breast Cancer Association Consortium. We confirmed previous reports of stronger associations with ER+ than ER- tumors for six of the eight loci identified in GWAS: rs2981582 (10q26) (P-heterogeneity = 6.1 × 10(-18)), rs3803662 (16q12) (P = 3.7 × 10(-5)), rs13281615 (8q24) (P = 0.002), rs13387042 (2q35) (P = 0.006), rs4973768 (3p24) (P = 0.003) and rs6504950 (17q23) (P = 0.002). The two candidate loci, CASP8 (rs1045485, rs17468277) and TGFB1 (rs1982073), were most strongly related with the risk of PR negative tumors (P = 5.1 × 10(-6) and P = 4.1 × 10(-4), respectively), as previously suggested. Four of the eight loci identified in GWAS were associated with triple negative tumors (P ≤ 0.016): rs3803662 (16q12), rs889312 (5q11), rs3817198 (11p15) and rs13387042 (2q35); however, only two of them (16q12 and 2q35) were associated with tumors with the core basal phenotype (P ≤ 0.002). These analyses are consistent with different biological origins of breast cancers, and indicate that tumor stratification might help in the identification and characterization of novel risk factors for breast cancer subtypes. This may eventually result in further improvements in prevention, early detection and treatment.


Enhancement of oral bioavailability of 20(S)-ginsenoside Rh2 through improved understanding of its absorption and efflux mechanisms.
The development of 20(S)-ginsenoside Rh2 (Rh2s) as a chemoprevention agent is limited by its low oral bioavailability. The goals of this study were to determine the mechanisms responsible for its poor oral absorption and to improve its bioavailability by overcoming the barrier to its absorption. Comprehensive studies were conducted using the following models: 1) monolayers of Caco-2, parental, and multidrug resistance gene (MDR1)-overexpressing Madin-Darby canine kidney II (MDCKII) cells; 2) pharmacokinetics in wild-type (WT) FVB, MDR1a/b knockout [MDR1a/b⁻/⁻] FVB, and A/J mice; and 3) intestinal perfusion in WT, MDR1a/b⁻/⁻ FVB, and A/J mice. Two P-glycoprotein (P-gp) inhibitors, verapamil and cyclosporine A, substantially decreased the efflux ratio of Rh2s from 28.5 to 1.0 and 1.2, respectively, in Caco-2 cells. The intracellular concentrations of Rh2s were also significantly increased (2.3- and 3.9-fold) in the presence of inhibitors. Similar results were obtained when transcellular transport of Rh2s were determined using MDR1-overexpressing MDCKII cells in the absence or presence of cyclosporine A. Compared with WT mice, the plasma C(max) and AUC₀-∞ of Rh2s were substantially increased by 17- and 23-fold in MDR1a/b⁻/⁻ FVB mice, respectively. In the A/J mice, the oral bioavailability of Rh2s (0.94% at 5 mg/kg and 0.52% at 20 mg/kg) was substantially increased by P-gp inhibitor to 33.18 and 27.14%, respectively. As expected, deletion or inhibition of P-gp significantly increased absorption and steady-state plasma concentration of Rh2s in a mouse intestinal perfusion model. In conclusion, Rh2s is a good substrate of P-gp, and inhibition of P-gp can significantly enhance its oral bioavailability.


Effect of insulin-induced hypoglycaemia on antral, pyloric and duodenal motility in fasting subjects.
1. Hyperglycaemia alters gastric motility and delays gastric emptying. By contrast, there is little information regarding the effect of sub-normal blood glucose concentrations on gastric and, in particular, pyloric motility, although limited data suggest that hypoglycaemia is associated with accelerated gastric emptying despite an apparently increased basal pyloric pressure. 2. To determine the effects of hypoglycaemia on pyloric motility, we compared the effects of an intravenous injection of insulin (0.15 units/kg) with those of a placebo injection of saline in eight healthy human volunteers during phase I of the interdigestive migrating motor complex. 3. All subjects developed profound hypoglycaemia (mean blood glucose concentration 1.6 mmol/l compared with 4.0 mmol/l in the control group). 4. There was no significant difference in the number of antral (9 versus 7, P = 0.34), pyloric (3 versus 0, P = 0.31) or duodenal (21 versus 13, P = 0.42) pressure waves or in the basal pyloric pressure (0.3 mmHg versus 0.1 mmHg, P = 0.37) in the 45 min after insulin injection (hypoglycaemia) when compared with the 45 min after saline injection (euglycaemia). In both the euglycaemic and hypoglycaemic studies there was a time-dependent increase in the numbers of antral and duodenal waves consistent with the expected changes in the interdigestive migrating motor complex. 5. These results indicate that insulin-induced hypoglycaemia has no significant effect on pyloric motility during phase I of the interdigestive migrating motor complex.


The effect of epidermal growth factor on the septic complications of acute pancreatitis.
Bacterial translocation (BT) from the gastrointestinal tract to mesenteric lymph nodes (MLN) and other extraintestinal organs is an important source of infection in acute pancreatitis (AP). Epidermal growth factor (EGF), a peptide hormone with trophic effects on gut mucosa, has decreased intestinal mucosal injury in septic rats and decreased burn-induced BT in mice. The purpose of this study is to examine whether EGF could affect BT in acute necrotizing pancreatitis. Forty-eight male Sprague-Dawley rats (250-350 g) were studied. AP was induced in Group I and Group II by pressure injection of 3% taurocholate and trypsin into the biliopancreatic duct (1 ml/kg of body weight). Group III and Group IV underwent laparotomy without induction of acute pancreatitis. Group I rats received human recombinant EGF (100 micrograms/kg, subcutaneously twice daily) and Group II rats received a similar volume of 0.1% bovine serum albumin as a placebo postoperatively. Group III and Group IV received EGF and placebo, respectively. At 48 hr postoperatively, blood was drawn for culture and amylase determinations. Jejunum and ileum were obtained to measure mucosal protein content, mucosal thickness, villus height, and crypt depth. Specimens from MLN, spleen, liver, pancreas, and cecum were harvested for pathology and culture of gram positive (G+), gram negative (G-), and anaerobic bacteria. Ileal mucosal protein levels were increased significantly in Group I (1.96 +/- 0.14 mg/cm) compared to Group II (0.95 +/- 0.15 mg/cm intestinal segment) (P < 0.01). Jejunal and ileal mucosal thickness, villus height, and crypt depth in Group I were significantly increased when compared to Group II (P < 0.05). All 12 rats in Group II had BT to MLN compared to 58% (7 of 12 rats) in Group I (P < 0.05). Thirty-three percent (4 of 12 rats) had BT to distant sites such as pancreas, spleen, liver, and/or blood in Group I vs 83% (10 of 12 rats) in Group II (P < 0.05). EGF treatment minimizes intestinal damage, decreases BT to MLN and bacterial spread to distant sites, and may be beneficial in preventing septic complications in AP.


OAS proteins and cGAS: unifying concepts in sensing and responding to cytosolic nucleic acids.
Recent discoveries in the field of innate immunity have highlighted the existence of a family of nucleic acid-sensing proteins that have similar structural and functional properties. These include the well-known oligoadenylate synthase (OAS) family proteins and the recently identified OAS homologue cyclic GMP-AMP (cGAMP) synthase (cGAS). The OAS proteins and cGAS are template-independent nucleotidyltransferases that, once activated by double-stranded nucleic acids in the cytosol, produce unique classes of 2'-5'-linked second messenger molecules, which - through distinct mechanisms - have crucial antiviral functions. 2'-5'-linked oligoadenylates limit viral propagation through the activation of the enzyme RNase L, which degrades host and viral RNA, and 2'-5'-linked cGAMP activates downstream signalling pathways to induce de novo antiviral gene expression. In this Progress article, we describe the striking functional and structural similarities between OAS proteins and cGAS, and highlight their roles in antiviral immunity.


Long-term stability of orthodontic treatment and patient satisfaction. A systematic review.
To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment. Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies. The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective. This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.


Magnetic resonance imaging of the brain in patients with pseudoexfoliation syndrome and glaucoma.
To evaluate ischemic changes in brain magnetic resonance images in patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) and compare them with age- and sex-matched control subjects. This case-control study involved 16 consecutive patients with PXS, 21 patients with PXG and 18 healthy age- and sex-matched control subjects. Each subject underwent a comprehensive ophthalmological examination. In all participants, an axial T(1)-, T(2)- and proton-density-weighted and coronal cerebral 1.5-tesla magnetic resonance imaging (MRI) scan was made. White matter hyperintensities (WMH) were considered present if these were hyperintense on both proton-density- and T(2)-weighted images and not hypointense on T(1)-weighted images. White matter lesions were classified into two parts as the subcortical and periventricular regions. We used a validated rating scale of subcortical WMH: 0 = absent, 1 = punctuate foci, 2 = beginning confluence of foci and 3 = large confluent areas. Periventricular white matter lesions were classified on a scale of 0 (no white matter lesions), 1 (pencil-thin periventricular lining), 2 (thick lining) or 3 (large confluent white matter lesions). The proportions of persons with WMH were 93.7% for patients with PXS, 95.2% for patients with PXG and 55.5% for control subjects. The numbers of white matter lesions in patients with PXS and PXG were significantly greater than in the control subjects (p < 0.05). White matter lesions at subcortical locations in patients with PXG were significantly more frequent than in the control subjects (80.9 vs. 33.3%; p < 0.05). The proportion of patients with subcortical WMH was 56.2% in PXS; no significant difference was found in subcortical WMH between PXS and controls. The proportions of patients with periventricular WMH were 93% in PXS, 90.4% in PXG and 44.4% in controls. White matter lesions at periventricular locations in patients with PXG and PXS were significantly more frequent than in the control subjects (p < 0.05). The difference between the pseudoexfoliation groups and controls with regard to the size of periventricular and subcortical white matter lesions was statically significant (p < 0.05). When patients with PXS were compared with PXG patients, there was no statistically significant difference in the number, size and scale of white matter lesions. We found a significantly higher prevalence of MRI-defined WMH in patients with a clinical diagnosis of pseudoexfoliation with or without glaucoma versus control subjects. We think that the findings in this study may shed light on a possible link between ischemic brain lesions and pseudoexfoliation, which is not related with the presence of glaucomatous optic neuropathy. Further investigations are required to resolve the underlying associations.


The ameliorative effects of boron against acrylamide-induced oxidative stress, inflammatory response, and metabolic changes in rats.
Acrylamide (ACR) is a hazardous substance associated with the accumulation of excessive reactive oxygen species and causes oxidative stress. Presence of ACR in foods leads to public health concerns due to its known neurotoxic, genotoxic, and carcinogenic effects. The present study investigated the ameliorative effects of boron (B) against ACR exposed rats. Forty Wistar albino male rats, fed with low-boron diet, were randomly and equally allocated into 5 groups. The control group was orally treated with physiological saline as placebo, the second group was orally given 15 mg/kg ACR. The other groups were orally treated with 15 mg/kg ACR and B at the levels of 5, 10, and 20 mg/kg/day for 60 days, respectively. ACR-treatment significantly increased malondialdehyde levels whereas decreased glutathione levels in rat tissues. Also, ACR-treatment increased the activities of superoxide dismutase and catalase in erythrocytes and tissues. Meanwhile, mRNA expression levels of NFĸB, IFN-γ, IL-1β, and TNF-α in liver and brain of rats were increased under ACR treatment. Additionally, ACR caused a significant decrease in the level of high-density lipoprotein, with increase in the levels of low-density lipoprotein, triglyceride, cholesterol, glucose, urea nitrogen, and creatinine. Lastly, B alleviated histopathological alterations induced by ACR in rat tissues.


Determinants of Three-Year Change in Children's Objectively Measured Sedentary Time.
Sedentary behaviours (SB) are highly prevalent in young people and may be adversely associated with physical and mental health. Understanding of the modifiable determinants of SB is necessary to inform the design of behaviour change interventions but much of the existing research is cross-sectional and focussed upon screen-based behaviours. To examine the social, psychological and environmental determinants of change in children's objectively measured sedentary time from age 11 to 14 years. Data are from the second (2008) and third (2011) waves of assessment in the Sport, Physical Activity, and Eating Behaviour: Environmental Determinants in Young People (SPEEDY) study, conducted in the county of Norfolk, United Kingdom. Longitudinal data on accelerometer assessed sedentary time were available for 316 (53.5% female, 11.2±0.3 years at baseline) and 264 children after-school and at the weekend respectively. Information on 14 candidate determinants, including school travel mode and electronic media ownership, was self-reported. Change in the proportion of registered time spent sedentary was used as the outcome variable in cross-classified linear regression models, adjusted for age, sex, body mass index and baseline sedentary time. Simple and multiple models were run and interactions with sex explored. Daily sedentary time increased by 30-40 minutes after-school and at the weekend from baseline to follow-up. Participants who travelled to school by cycle exhibited smaller increases in after-school sedentary time (beta; 95%CI for change in % time spent sedentary: -3.3;-6.7,-0.07). No significant determinants of change in weekend sedentary time were identified. Time spent sedentary increased during the three-year duration of follow-up but few of the variables examined were significantly associated with changes in sedentary time. Children's mode of school travel may influence changes in their sedentary time over this period and should be examined further, alongside broader efforts to identify modifiable determinants of SB during childhood.


[Legal action as mechanisms of protection the right to health in Manizales, Colombia].
Characterising legal action taken for protecting health rights in Manizales during 2003 and 2004. This was a descriptive kind of study, based on a sample of 375 legal actions filed in the city of Manizales' legal offices during 2003 and 2004. The study was carried out in two steps; the files kept in the legal offices were reviewed and semi-structured interviews were held with personnel from the General Social Health Security System (GSHSS), monitoring and control centres, the legal offices and the academic sector. Their concept regarding legal action and its subsequent impact on the health services was also consulted. 54.2% of the 375 legal actions were brought by women. Information regarding age was only registered in 53.8% of the files consulted; 81% of these corresponded to the population group aged older than 25 and 3% were presented by the population group less than 5 years of age. 74.7% of the people were in the regime making contributions and 14% in the subsidized regime. Most reasons for making a claim were made on at least two grounds, including complaints about integral treatment including drug prescriptions, exams, surgery, specialist appointments, carrying out procedures, etc. Taking legal action has become the most effective tool for gaining access to health services in Manizales.


Prevalence of antibodies to spotted fever group rickettsiae in humans and domestic animals in a Brazilian spotted fever-endemic area in the state of São Paulo, Brazil: serologic evidence for infection by Rickettsia rickettsii and another spotted fever group Rickettsia.
In serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three farms in the Pedreira Municipality, an endemic area for Brazilian spotted fever, an indirect immunofluorescence assay (IFA) detected antibodies against Rickettsia rickettsii in 17 (77.3%) horses, 5 (31.3%) dogs (titers ranging from 64 to 4,048), and none of 4 donkeys or 50 humans. Five canine and eight equine sera with high antibody titers to R. rickettsii were also tested by IFA against R. bellii, R. akari, and R. africae antigens. Sera from two horses and two dogs that showed similar high antibody titers against two rickettsial antigens were evaluated after cross-absorption. Sera from seven horses and two dogs contained antibodies specific for R. rickettsii, and one dog serum had antibodies against a Rickettsia species very closely related to R. africae. The latter may have been caused by infection with the recently identified COOPERI strain.


Engagement and skill development in biology students through analysis of art.
An activity involving analysis of art in biology courses was designed with the goals of piquing undergraduates' curiosity, broadening the ways in which college students meaningfully engage with course content and concepts, and developing aspects of students' higher-level thinking skills, such as analysis, synthesis, and evaluation. To meet these learning outcomes, the activity had three key components: preparatory readings, first-hand visual analysis of art during a visit to an art museum, and communication of the analysis. Following a presentation on the methodology of visual analysis, students worked in small groups to examine through the disciplinary lens of biology a selection of approximately 12 original artworks related in some manner to love. The groups then developed and presented for class members a mini-exhibition of several pieces addressing one of two questions: 1) whether portrayals of love in art align with the growing understanding of the biology of love or 2) whether the bodily experience of love is universal or, alternatively, is culturally influenced, as is the experience of depression. Evaluation of quantitative and qualitative assessment data revealed that the assignment engaged students, supported development of higher-level thinking skills, and prompted meaningful engagement with course material.


Small-scale demixing in confluent biological tissues.
Surface tension governed by differential adhesion can drive fluid particle mixtures to sort into separate regions, i.e., demix. Does the same phenomenon occur in confluent biological tissues? We begin to answer this question for epithelial monolayers with a combination of theory via a vertex model and experiments on keratinocyte monolayers. Vertex models are distinct from particle models in that the interactions between the cells are shape-based, as opposed to distance-dependent. We investigate whether a disparity in cell shape or size alone is sufficient to drive demixing in bidisperse vertex model fluid mixtures. Surprisingly, we observe that both types of bidisperse systems robustly mix on large lengthscales. On the other hand, shape disparity generates slight demixing over a few cell diameters, a phenomenon we term micro-demixing. This result can be understood by examining the differential energy barriers for neighbor exchanges (T1 transitions). Experiments with mixtures of wild-type and E-cadherin-deficient keratinocytes on a substrate are consistent with the predicted phenomenon of micro-demixing, which biology may exploit to create subtle patterning. The robustness of mixing at large scales, however, suggests that despite some differences in cell shape and size, progenitor cells can readily mix throughout a developing tissue until acquiring means of recognizing cells of different types.


Expression of human prepro-orexin and signaling characteristics of orexin receptors in the male reproductive system.
Orexin-A (OR-A) and OR-B are derived from a common 130-amino acid precursor peptide, prepro-OR, by proteolytic cleavage. Orexins orchestrate their actions by binding and activating two types of G protein-coupled receptors, OR-1 receptor (OX1R) and OR-2 receptor (OX2R). Besides playing a role in the regulation of feeding and energy homeostasis in rats, ORs appear to increase sexual arousal as well as copulatory performance in rats. Furthermore, OR-A and -B immunoreactivity has been detected in rat testis. In view of these findings we investigated the expression of OR receptors and their signaling characteristics in the human male reproductive system. Using RT-PCR analysis, we were able to demonstrate that both OX1R and OX2R are expressed in the testis, epididymis, penis, and seminal vesicle, whereas prepro-OR was expressed only in the epididymis and penis. Protein expression of both OR receptors in human testis was confirmed by Western blotting analysis, with apparent molecular masses of 50 kDa for OX1R and 40 kDa for OX2R. Immunofluorescent studies revealed staining for both OX1R and OX2R in Leydig cells, myoid cells of the seminiferous tubules, and Sertoli cells. To test the ability of ORs to activate testicular phospholipase C, we determined the effects of OR-A and OR-B on inositol trisphosphate production. When membranes from testicular biopsies were incubated with OR-A or OR-B, there was a rapid inositol trisphosphate turnover. This effect appeared to be dose dependent. These data provide a novel insight into the expression and signaling characteristics of OR receptors in the human male reproductive system and potentially further implicate these peptides, acting in an autocrine/paracrine manner, in the regulation of arousal mechanisms in humans.


How case characteristics differ across four types of elder maltreatment: implications for tailoring interventions to increase victim safety.
The purpose of this study was to determine whether case characteristics are differentially associated with four forms of elder maltreatment. Triangulated interviews were conducted with 71 APS caseworkers, 55 victims of substantiated abuse whose cases they managed, and 35 third party persons. Pure financial exploitation (PFE) was characterized by victim unawareness of financial exploitation and living alone. Physical abuse (PA) was characterized by victim's desire to protect the abusive individual. Neglect was characterized by isolation and victim's residing with the abusive individual. Hybrid financial exploitation (HFE) was characterized by mutual dependency. These differences indicate the need for tailoring interventions to increase victim safety. PFE requires victims to maintain financial security and independence. PA requires services to meet the needs of abusive individuals. Neglect requires greater monitoring when elderly persons reside with another person. HFE requires the provision of services to both members of the dyad.


Cerebrovascular and ischemic heart disease in young adults born preterm: a population-based Swedish cohort study.
Preterm birth is associated with overall cardiovascular mortality in young adulthood, but which specific conditions that underlie this association is unknown. We studied mortality and morbidity from cerebrovascular and ischemic heart disease in individuals born preterm. In a nationwide Swedish study, we included 1,306,943 individuals without congenital malformations born between 1983 and 1995, followed from 15 years of age to December 31st, 2010. Of these, 73,489 (5.6 %) were born preterm (<37 weeks of gestation). Cox proportional hazards regression analysis was used to calculate hazard ratios (HR) with 95 % confidence intervals (CI), after adjusting for maternal characteristics and birth weight for gestational age. Of 955 incident cases of cerebrovascular disease, 58 (6.1 %) occurred in preterm born subjects. The corresponding numbers of ischemic heart disease cases were 180 and 13 (7.2 %), respectively. Birth before 32 weeks was associated with a nearly twofold increased risk of cerebrovascular disease; adjusted HR, (95 % CI) = 1.89 (1.01-3.54) compared to term born individuals, whereas individuals born at 32-36 weeks were not at increased risk. Preterm birth was not associated with later ischemic heart disease; no cases of ischemic heart disease were recorded among those born before 32 weeks and the HR (95 % CI) for those born at 32-36 weeks of gestation was 1.45 (0.81-2.57), compared to term-born individuals. Birth before 32 weeks is associated with increased risk of cerebrovascular disease in young adulthood. Our data suggest that cardiovascular health promotion in follow-up programs after very preterm birth may be beneficial.


Decreased gut microbiota diversity, delayed Bacteroidetes colonisation and reduced Th1 responses in infants delivered by caesarean section.
The early intestinal microbiota exerts important stimuli for immune development, and a reduced microbial exposure as well as caesarean section (CS) has been associated with the development of allergic disease. Here we address how microbiota development in infants is affected by mode of delivery, and relate differences in colonisation patterns to the maturation of a balanced Th1/Th2 immune response. The postnatal intestinal colonisation pattern was investigated in 24 infants, born vaginally (15) or by CS (nine). The intestinal microbiota were characterised using pyrosequencing of 16S rRNA genes at 1 week and 1, 3, 6, 12 and 24 months after birth. Venous blood levels of Th1- and Th2-associated chemokines were measured at 6, 12 and 24 months. Infants born through CS had lower total microbiota diversity during the first 2 years of life. CS delivered infants also had a lower abundance and diversity of the Bacteroidetes phylum and were less often colonised with the Bacteroidetes phylum. Infants born through CS had significantly lower levels of the Th1-associated chemokines CXCL10 and CXCL11 in blood. CS was associated with a lower total microbial diversity, delayed colonisation of the Bacteroidetes phylum and reduced Th1 responses during the first 2 years of life.


Glioblastoma and the search for non-hypothesis driven combination therapeutics in academia.
Glioblastoma (GBM) remains a cancer of high unmet clinical need. Current standard of care for GBM, consisting of maximal surgical resection, followed by ionisation radiation (IR) plus concomitant and adjuvant temozolomide (TMZ), provides less than 15-month survival benefit. Efforts by conventional drug discovery to improve overall survival have failed to overcome challenges presented by inherent tumor heterogeneity, therapeutic resistance attributed to GBM stem cells, and tumor niches supporting self-renewal. In this review we describe the steps academic researchers are taking to address these limitations in high throughput screening programs to identify novel GBM combinatorial targets. We detail how they are implementing more physiologically relevant phenotypic assays which better recapitulate key areas of disease biology coupled with more focussed libraries of small compounds, such as drug repurposing, target discovery, pharmacologically active and novel, more comprehensive anti-cancer target-annotated compound libraries. Herein, we discuss the rationale for current GBM combination trials and the need for more systematic and transparent strategies for identification, validation and prioritisation of combinations that lead to clinical trials. Finally, we make specific recommendations to the preclinical, small compound screening paradigm that could increase the likelihood of identifying tractable, combinatorial, small molecule inhibitors and better drug targets specific to GBM.


Serum albumin and comorbidity relative to rehabilitation outcome in geriatric stroke, and possible links with stroke etiology.
Factors that describe the disability status of the stroke patient on discharge are important when starting a rehabilitation program, both from a psychosocial and a financial point of view. The objective of this study was to assess how comorbidity and serum albumin levels relate to rehabilitation outcome in geriatric stroke patients. Another aim was to assess whether stroke etiology (ischemic or hemorrhagic) influences these links. Medical records of 80 patients (68 ischemic and 12 hemorrhagic strokes) older than 65 years, who had suffered their first stroke, were investigated. Functional performance levels at admission and discharge were evaluated using the Functional Independence Measure (FIM). Length of stay in hospital was recorded. Serum albumin levels and comorbidity scores on admission were noted. Correlations between these variables and differences between the groups categorized according to stroke etiology were analyzed. In the group of geriatric stroke patients as a whole, serum albumin level was correlated with FIM score at admission and discharge. Comorbidity score was negatively correlated with length of stay. In the ischemic stroke subgroup, serum albumin level was positively correlated with length of stay and with functional gain, and comorbidity score was negatively correlated with functional gain. Analysis of the data for the hemorrhagic stroke subgroup revealed none of these correlations. It was concluded that serum albumin level and comorbidity are useful indices in geriatric ischemic stroke patients for predicting functional outcome and time spent in rehabilitation.


Suppression of Helicobacter pylori reduces gastrin releasing peptide stimulated gastrin release in duodenal ulcer patients.
Helicobacter pylori increases gastrin release in duodenal ulcer patients. This may be through disruption or changes in the mucus layer affecting the access of luminal stimulants to gastrin releasing cells. The effect of suppressing H pylori on gastrin release stimulated by a non-luminal stimulus, gastrin releasing peptide (GRP), was examined. Eleven patients with active duodenal ulcer disease and colonised with H pylori received an intravenous infusion of GRP (2.9 pmol/kg/minute for 30 minutes) and the plasma gastrin response was measured. Basal and peak pentagastrin stimulated acid output were also determined. Patients were treated with tripotassium dicitratobismuthate (De-Nol) and metronidazole to suppress H pylori and the tests were repeated. Suppression of H pylori decreased plasma gastrin concentrations during GRP infusion, but acid output was not affected. Chromatographic analysis of the forms of gastrin in plasma showed a significant fall in gastrin 17, the predominant form found in the gastric antrum. Gastrin 34 did not fall significantly. This study shows that suppression of H pylori decreases the hypergastrinaemia caused by the nonluminal stimulant, GRP, mainly via decreasing gastrin 17.


Multi-informant reports of mental health in Swedish-born children of immigrants and children born to non-immigrants - the SESBiC-study.
The European literature on mental health of the children of immigrants is limited. Therefore this study aims to investigate gender-specific mental health reported by teachers, parents and the children themselves in 12-year old children of immigrants and non-immigrants and also to study the level of agreement between the different informants. This cross-sectional study is a part of the longitudinal South East Sweden Birth Cohort-study (the SESBiC-study) on children's health. All children born in town in the south of Sweden 1995-1996 were invited to take part. The mothers of 1723 children (88%) consented. In this part 87 Swedish-born 12-year old children of immigrants and 687 12-year old children of non-immigrants were investigated regarding gender-specific differences in mental health as reported by teachers (Teacher-report form), parents (Child behavior checklist), and children (Strengths and Difficulties Questionnaire) and the agreement reached between the informants. Parental immigrant status was not associated with mental health in any of the groups, but living arrangements and parental educational level were mainly found to have an effect on the health status of boys (TRF-Internalizing β = .77 95% CI = .02-1.52; TRF-Externalizing.β = 2.31 95% CI = .63-3.99; TRF-Total β = 6.22 95% CI = 2.27-10.18) The agreement between different informants was generally low, except for externalizing problems among boys (Boys of immigrant parents: Parent and teacher correlation ρ = .422 and Child teacher correlation ρ = .524, p-value < .05, respectively). The correlation between teachers and parents were lower in the index group compared to the reference group. In the index group, the correlations between teacher's and children's assessments were fairly high for boys but not for girls (ρ Total = .400, ρ Internalizing = .240 and ρ Externalizing = .524, p-value < .05 for Total and Externalizing). This study confirms previous findings that the mental health of children of immigrants is similar to that of children of non-immigrants. We found that family factors have a greater impact on the reported mental health than immigrant status does. This might be of clinical importance for healthcare workers to recognize when investigating and treating children from other cultures.


A living cell quartz crystal microbalance biosensor for continuous monitoring of cytotoxic responses of macrophages to single-walled carbon nanotubes.
Numerous engineered nanomaterials (ENMs) exist and new ENMs are being developed. A challenge to nanotoxicology and environmental health and safety is evaluating toxicity of ENMs before they become widely utilized. Cellular assays remain the predominant test platform yet these methods are limited by using discrete time endpoints and reliance on organic dyes, vulnerable to interference from ENMs. Label-free, continuous, rapid response systems with biologically meaningful endpoints are needed. We have developed a device to detect and monitor in real time responses of living cells to ENMs. The device, a living cell quartz crystal microbalance biosensor (QCMB), uses macrophages adherent to a quartz crystal. The communal response of macrophages to treatments is monitored continuously as changes in crystal oscillation frequency (Δf). We report the ability of this QCMB to distinguish benign from toxic exposures and reveal unique kinetic information about cellular responses to varying doses of single-walled carbon nanotubes (SWCNTs). We analyzed macrophage responses to additions of Zymosan A, polystyrene beads (PBs) (benign substances) or SWCNT (3-150 μg/ml) in the QCMB over 18 hrs. In parallel, toxicity was monitored over 24/48 hrs using conventional viability assays and histological stains to detect apoptosis. In the QCMB, a stable unchanging oscillation frequency occurred when cells alone, Zymosan A alone, PBs alone or SWCNTs without cells at the highest dose alone were used. With living cells in the QCMB, when Zymosan A, PBs or SWCNTs were added, a significant decrease in frequency occurred from 1-6 hrs. For SWCNTs, this Δf was dose-dependent. From 6-18 hrs, benign substances or low dose SWCNT (3-30 μg/ml) treatments showed a reversal of the decrease of oscillation frequency, returning to or exceeding pre-treatment levels. Cell recovery was confirmed in conventional assays. The lag time to see the Δf reversal in QCMB plots was linearly SWCNT-dose dependent. Lastly, the frequency never reversed at high dose SWCNT (100-150 μg/ml), and apoptosis/necrosis was documented in conventional 24 and 48 hr-assays. These data suggest that the new QCMB detects and provides unique information about peak, sub-lethal and toxic exposures of living cells to ENMs before they are detected using conventional cell assays.


A paradigm for identification of primary genetic causes of hypertension in rats.
A paradigm is developed for identifying the genes (and the biochemical-physiological traits for which the genes code) that cause differences in blood pressure in inbred strains of rats. A biochemical-physiological trait which meets the following four criteria is one which can reasonably be accepted as causing genetic differences in blood pressure: 1) a difference in a biochemical or physiological trait between two strains must be demonstrated; 2) the trait must be shown to follow Mendelian inheritance; 3) the genes identified in criterion 2 must co-segregate with an increment in blood pressure which is significantly different from zero; and 4) there must be some logical biochemical and/or physiological link between the trait and blood pressure. Traits which do not show discrete phenotypes following Mendelian inheritance may correlate with blood pressure in segregating populations. In this case no rigorous cause and effect genetic argument is possible because such correlations could arise from complex primary genetic causes or as secondary effects of blood pressure on the biochemical-physiological trait.


A study of head and eye movement in spasmus nutans.
A case of spasmus nutans was studied using objective recordings of head and eye displacement in order to generate a precise description of the ocular oscillations and head nodding and to investigate their interrelationships. The ocularoscillations consisted of 11-Hz sinusoidal convergence movements. The head nodding consisted of a 3-Hz, 3 degrees peak to peak, sinusoidal oscillation in the horizontal plane. The occurrence of the nodding always abolished the ocular oscillation which was replaced by normal compensatory eye movements which assisted visual acuity. The hypothesis is made that the head nodding is not pathological; it is a learned behavioural pattern which permits the patient to nullify the pathological eye movements. In order to test this hypothesis further, objective evidence is required to determine the precise order of appearance of the abnormal head and eye movements in spasmus nutans.


Risk Factors, Mortality, and Cardiovascular Outcomes in Patients with Type 2 Diabetes.
Patients with diabetes are at higher risk for death and cardiovascular outcomes than the general population. We investigated whether the excess risk of death and cardiovascular events among patients with type 2 diabetes could be reduced or eliminated. In a cohort study, we included 271,174 patients with type 2 diabetes who were registered in the Swedish National Diabetes Register and matched them with 1,355,870 controls on the basis of age, sex, and county. We assessed patients with diabetes according to age categories and according to the presence of five risk factors (elevated glycated hemoglobin level, elevated low-density lipoprotein cholesterol level, albuminuria, smoking, and elevated blood pressure). Cox regression was used to study the excess risk of outcomes (death, acute myocardial infarction, stroke, and hospitalization for heart failure) associated with smoking and the number of variables outside target ranges. We also examined the relationship between various risk factors and cardiovascular outcomes. The median follow-up among all the study participants was 5.7 years, during which 175,345 deaths occurred. Among patients with type 2 diabetes, the excess risk of outcomes decreased stepwise for each risk-factor variable within the target range. Among patients with diabetes who had all five variables within target ranges, the hazard ratio for death from any cause, as compared with controls, was 1.06 (95% confidence interval [CI], 1.00 to 1.12), the hazard ratio for acute myocardial infarction was 0.84 (95% CI, 0.75 to 0.93), and the hazard ratio for stroke was 0.95 (95% CI, 0.84 to 1.07). The risk of hospitalization for heart failure was consistently higher among patients with diabetes than among controls (hazard ratio, 1.45; 95% CI, 1.34 to 1.57). In patients with type 2 diabetes, a glycated hemoglobin level outside the target range was the strongest predictor of stroke and acute myocardial infarction; smoking was the strongest predictor of death. Patients with type 2 diabetes who had five risk-factor variables within the target ranges appeared to have little or no excess risk of death, myocardial infarction, or stroke, as compared with the general population. (Funded by the Swedish Association of Local Authorities and Regions and others.).


Statistical air quality predictions for public health surveillance: evaluation and generation of county level metrics of PM2.5 for the environmental public health tracking network.
The Centers for Disease Control and Prevention (CDC) developed county level metrics for the Environmental Public Health Tracking Network (Tracking Network) to characterize potential population exposure to airborne particles with an aerodynamic diameter of 2.5 μm or less (PM(2.5)). These metrics are based on Federal Reference Method (FRM) air monitor data in the Environmental Protection Agency (EPA) Air Quality System (AQS); however, monitor data are limited in space and time. In order to understand air quality in all areas and on days without monitor data, the CDC collaborated with the EPA in the development of hierarchical Bayesian (HB) based predictions of PM(2.5) concentrations. This paper describes the generation and evaluation of HB-based county level estimates of PM(2.5). We used three geo-imputation approaches to convert grid-level predictions to county level estimates. We used Pearson (r) and Kendall Tau-B (τ) correlation coefficients to assess the consistency of the relationship, and examined the direct differences (by county) between HB-based estimates and AQS-based concentrations at the daily level. We further compared the annual averages using Tukey mean-difference plots. During the year 2005, fewer than 20% of the counties in the conterminous United States (U.S.) had PM(2.5) monitoring and 32% of the conterminous U.S. population resided in counties with no AQS monitors. County level estimates resulting from population-weighted centroid containment approach were correlated more strongly with monitor-based concentrations (r = 0.9; τ = 0.8) than were estimates from other geo-imputation approaches. The median daily difference was -0.2 μg/m(3) with an interquartile range (IQR) of 1.9 μg/m(3) and the median relative daily difference was -2.2% with an IQR of 17.2%. Under-prediction was more prevalent at higher concentrations and for counties in the western U.S. While the relationship between county level HB-based estimates and AQS-based concentrations is generally good, there are clear variations in the strength of this relationship for different regions of the U.S. and at various concentrations of PM(2.5). This evaluation suggests that population-weighted county centroid containment method is an appropriate geo-imputation approach, and using the HB-based PM(2.5) estimates to augment gaps in AQS data provides a more spatially and temporally consistent basis for calculating the metrics deployed on the Tracking Network.


Deficiency of the chemokine receptor CXCR2 attenuates neutrophil infiltration and cortical damage following closed head injury.
The contribution of infiltrated neutrophils to secondary damage following traumatic brain injury remains controversial. Chemokines that regulate neutrophil migration by signaling through the CXCR2 receptor are markedly elevated by brain injury and are associated with the propagation of secondary damage. This study thus investigated the function of CXCR2 in posttraumatic inflammation and secondary degeneration by examining Cxcr2-deficient (Cxcr2(-/-)) mice over 14 days following closed head injury (CHI). We demonstrate a significant attenuation of neutrophil infiltration in Cxcr2(-/-) mice at 12 hours and 7 days after CHI, despite increased levels of CXC neutrophil-attracting chemokines in the lesioned cortex. This coincides with reduced tissue damage, neuronal loss, and cell death in Cxcr2(-/-) mice compared to wild-type controls, with heterozygotes showing intermediate responses. In contrast, blood-brain barrier permeability and functional recovery did not appear to be affected by Cxcr2 deletion. This study highlights the deleterious contribution of neutrophils to posttraumatic neurodegeneration and demonstrates the importance of CXC chemokine signaling in this process. Therefore, CXCR2 antagonistic therapeutics currently in development for other inflammatory conditions may also be of benefit in posttraumatic neuroinflammation.


Exercise as a synchroniser of human circadian rhythms: an update and discussion of the methodological problems.
We review the literature on whether exercise is a synchroniser of human circadian rhythms, and highlight the specific methodological problems that are associated with this topic. In applied research, exercise has been investigated as a treatment for jet lag and shift-work problems. In these studies, there have been difficulties in controlling the characteristics of the exercise bout, the athletic status of research participants and exposure to other confounding synchronisers. Therefore, it is unclear at present whether exercise can help mitigate the problems associated with transmeridian travel and shift-work. In laboratory-based experiments, participants have exercised at various times of the day and the change in phase of various circadian rhythms has been measured. Although it is difficult to control for the considerable masking effects of exercise on these estimates of circadian timing, it is clear that nocturnal exercise can induce phase delays in the onset of melatonin. Reports of exercise-induced phase advances of the melatonin rhythm are rarer, as are any phase-shifting effects at all on the body temperature rhythm. In practical terms, the substantial levels of activity needed to obtain phase shifts may not be attainable by the majority of people. In mechanistic terms, the lack of agreement with the phase-shifting effects of bright light suggests that exercise is not exerting its effects via photic entrainment pathways. An alternative explanation may involve exercise-induced hyperthermia. Moreover, it is perplexing why exercise should have a different phase response curve to light, given that humans are diurnally active.


Whole-genome analysis of a daptomycin-susceptible enterococcus faecium strain and its daptomycin-resistant variant arising during therapy.
Development of daptomycin (DAP) resistance in Enterococcus faecalis has recently been associated with mutations in genes encoding proteins with two main functions: (i) control of the cell envelope stress response to antibiotics and antimicrobial peptides (LiaFSR system) and (ii) cell membrane phospholipid metabolism (glycerophosphoryl diester phosphodiesterase and cardiolipin synthase [cls]). However, the genetic bases for DAP resistance in Enterococcus faecium are unclear. We performed whole-genome comparative analysis of a clinical strain pair, DAP-susceptible E. faecium S447 and its DAP-resistant derivative R446, which was recovered from a single patient during DAP therapy. By comparative whole-genome sequencing, DAP resistance in R446 was associated with changes in 8 genes. Two of these genes encoded proteins involved in phospholipid metabolism: (i) an R218Q substitution in Cls and (ii) an A292G reversion in a putative cyclopropane fatty acid synthase enzyme. The DAP-resistant derivative R446 also exhibited an S333L substitution in the putative histidine kinase YycG, a member of the YycFG system, which, similar to LiaFSR, has been involved in cell envelope homeostasis and DAP resistance in other Gram-positive cocci. Additional changes identified in E. faecium R446 (DAP resistant) included two putative proteins involved in transport (one for carbohydrate and one for sulfate) and three enzymes predicted to play a role in general metabolism. Exchange of the "susceptible" cls allele from S447 for the "resistant" one belonging to R446 did not affect DAP susceptibility. Our results suggest that, apart from the LiaFSR system, the essential YycFG system is likely to be an important mediator of DAP resistance in some E. faecium strains.


Synthetic peptides from conserved regions of the Plasmodium falciparum early transcribed membrane and ring exported proteins bind specifically to red blood cell proteins.
Severe malaria pathology is directly associated with cytoadherence of infected red blood cells (iRBCs) to healthy RBCs and/or endothelial cells occurring during the intraerythrocytic development of Plasmodium falciparum. We synthesized, as 20-mer long peptides, the members of the ring exported (REX) protein family encoded in chromosome 9, as well as the early transcribed membrane proteins (E-TRAMP) 10.2 and 4, to identify specific RBC binding regions in these proteins. Twelve binding peptides were identified (designated as HABPs): three were identified in REX1, two in REX2, one in REX3, two in REX4 and four in E-TRAMP 10.2. The majority of these HABPs was conserved among different P. falciparum strains, according to sequence analysis. No HABPs were found in E-TRAMP 4. Bindings of HABPs were saturable and sensitive to the enzymatic treatment of RBCs and HABPs had different structural features, according to circular dichroism studies. Our results suggest that the REX and E-TRAMP families participate in relevant interactions with RBC membrane proteins, which highlight these proteins as potential targets for the development of fully effective immunoprophylactic methods.


The distribution of epistasis on simple fitness landscapes.
Fitness interactions between mutations can influence a population's evolution in many different ways. While epistatic effects are difficult to measure precisely, important information is captured by the mean and variance of log fitnesses for individuals carrying different numbers of mutations. We derive predictions for these quantities from a class of simple fitness landscapes, based on models of optimizing selection on quantitative traits. We also explore extensions to the models, including modular pleiotropy, variable effect sizes, mutational bias and maladaptation of the wild type. We illustrate our approach by reanalysing a large dataset of mutant effects in a yeast snoRNA (small nucleolar RNA). Though characterized by some large epistatic effects, these data give a good overall fit to the non-epistatic null model, suggesting that epistasis might have limited influence on the evolutionary dynamics in this system. We also show how the amount of epistasis depends on both the underlying fitness landscape and the distribution of mutations, and so is expected to vary in consistent ways between new mutations, standing variation and fixed mutations.


Ligand selectivity by seeking hydrophobicity in thyroid hormone receptor.
Selective therapeutics for nuclear receptors would revolutionize treatment for endocrine disease. Specific control of nuclear receptor activity is challenging because the internal cavities that bind hormones can be virtually identical. Only one highly selective hormone analog is known for the thyroid receptor, GC-24, an agonist for human thyroid hormone receptor beta. The compound differs from natural hormone in benzyl, substituting for an iodine atom in the 3' position. The benzyl is too large to fit into the enclosed pocket of the receptor. The crystal structure of human thyroid hormone receptor beta at 2.8-A resolution with GC-24 bound explains its agonist activity and unique isoform specificity. The benzyl of GC-24 is accommodated through shifts of 3-4 A in two helices. These helices are required for binding hormone and positioning the critical helix 12 at the C terminus. Despite these changes, the complex associates with coactivator as tightly as human thyroid hormone receptor bound to thyroid hormone and is fully active. Our data suggest that increased specificity of ligand recognition derives from creating a new hydrophobic cluster with ligand and protein components.


Mechanical activation of cells induces chromatin remodeling preceding MKL nuclear transport.
For cells to adapt to different tissues and changes in tissue mechanics, they must be able to respond to mechanical cues by changing their gene expression patterns. Biochemical signaling pathways for these responses have been elucidated, and recent evidence points to the involvement of force-induced deformation of the nucleus. However, it is still unclear how physical cues received at the plasma membrane (PM) spatiotemporally integrate to the functional chromatin organization of the cell nucleus. To investigate this issue, we applied mechanical forces through magnetic particles adhered to the PM of single cells and mapped the accompanying changes in actin polymerization, nuclear morphology, chromatin remodeling, and nuclear transport of soluble signaling intermediates using high-resolution fluorescence anisotropy imaging. Using this approach, we show the timescales associated with force-induced polymerization of actin and changes in the F/G actin ratio resulting in nuclear translocation of the G-actin-associated transcriptional cofactor, megakaryoblastic acute leukemia factor-1 (MKL). Further, this method of measuring nuclear organization at high spatiotemporal resolution with simultaneous force application revealed the physical propagation of forces to the nucleus, resulting in changes to chromatin organization, followed by nuclear deformation. We also describe a quantitative model that incorporates active stresses and chemical kinetics to evaluate the observed timescales. Our work suggests that mechanical activation of cells is accompanied by distinct timescales involved in the reorganization of actin and chromatin assembly, followed by translocation of transcription cofactors from the cytoplasm to the nucleus.


Synthesis and organic solar cell performance of BODIPY and coumarin functionalized SWCNTs or graphene oxide nanomaterials.
The synthesis and characterization of new hybrid materials based on reduced graphene oxide (rGO) or single walled carbon nanotubes (SWCNTs) covalently functionalized by 4,4'-difluoro-8-(4-propynyloxy)-phenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY) (2) or 7-(prop-2-yn-1-yloxy)-3-(3',4',5'-trimethoxyphenyl)-coumarin (4) as light harvesting groups have been described. The organic solar cell performances of these novel nanomaterials in P3HT:PCBM blends were investigated. These covalently bonded hybrid materials (reduced graphene oxide:BODIPY (GB), reduced graphene oxide:Coumarin (GC), SWCNTs:BODIPY (CB) and SWCNTs:Coumarin (CC)) were prepared by an azide-alkyne Huisgen cycloaddition (click) reaction between the azide bearing SWCNTs or rGO and terminal ethynyl functionalized BODIPY (2) or coumarin (4) derivatives. The formation of novel nanomaterials was confirmed by FT-IR, UV-Vis and Raman spectroscopies and thermogravimetric analysis. The best performance on P3HT:PCBM organic solar cells was produced by SWCNTs:Coumarin (CC) hybrids which were coated on an indium tin oxide coated polyethylene terephthalate film (ITO-PET). The reference device based on the P3HT:PCBM blend without CC showed a power conversion efficiency (PCE) of 1.16%, an FF of 35% and a short-circuit current density (Jsc) of 5.51 mA cm-2. The reference device with CC hybrids within the P3HT:PCBM blend increased the values significantly to 1.62% for PCE, 40% for FF and 6.8 mA cm-2 for Jsc.