223 research outputs found

    Aerobic degradation of phytoplankton debris dominated by Phaeocystis sp in different physiological stages of growth

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    The aerobic degradation of phytoplankton debris collected in Dutch coastal waters on 2 days in 1991 (15 April and 8 May), representing 2 physiological stages of a phytoplankton spring bloom dominated by Phaeocystis sp., was studied in batch culture experiments. The bacterial production and the concentrations of particulate organic carbon (POC) and dissolved organic carbon (DOG) were monitored over a period of 102 d. Bacterial numbers and biomass were followed for 35 d. All experiments showed a rapid metabolic response of bacteria and a sharp decrease in the concentration of POC and DOC during the first days of the experiments. Thereafter bacterial production rates remained constant, and POC and DOC decreased slowly. Apparently, the phytoplankton debris consisted of a labile, rapidly degradable fraction and a refractory, slowly degradable fraction. The labile fraction comprised approximately 50 % of the debris, and was degraded with a bacterial carbon conversion efficiency of between 10 and 20%. There were no indications that antibiotic compounds present in the algal debris inhibited the degradation. Acrylate, a proposed antibiotic compound which was present in the algal debris, was rapidly degraded in a control experiment. The percentage of the material that had been degraded after 102 d was highest in the experiment with material collected in May. It was concluded that during the early phase of the bloom, more refractory compounds are produced

    HSPG-Binding Peptide Corresponding to the Exon 6a-Encoded Domain of VEGF Inhibits Tumor Growth by Blocking Angiogenesis in Murine Model

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    Vascular endothelial growth factor VEGF165 is a critical element for development of the vascular system in physiological and pathological angiogenesis. VEGF isoforms have different affinities for heparan sulphate proteoglycan (HSPG) as well as for VEGF receptors; HSPGs are important regulators in vascular development. Therefore, inhibition of interactions between VEGF and HSPGs may prevent angiogenesis. Here, we demonstrate that an HSPG-binding synthetic peptide, corresponding to exon 6a-encoded domain of VEGF gene, has anti-angiogenic property. This 20 amino acids synthetic peptide prevents VEGF165 binding to several different cell types, mouse embryonic sections and inhibits endothelial cell migration, despite its absence in VEGF165 sequence. Our in vivo anti-tumor studies show that the peptide inhibits tumor growth in both mouse Lewis-Lung Carcinoma and human Liposarcoma tumor-bearing animal models. This is the first evidence that a synthetic VEGF fragment corresponding to exon 6a has functional antagonism both in vitro and in vivo. We conclude that the above HPSG binding peptide (6a-P) is a potent inhibitor of angiogenesis-dependent diseases

    Inhibition decorrelates visual feature representations in the inner retina

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    The retina extracts visual features for transmission to the brain. Different types of bipolar cell split the photoreceptor input into parallel channels and provide the excitatory drive for downstream visual circuits. Mouse bipolar cell types have been described at great anatomical and genetic detail, but a similarly deep understanding of their functional diversity is lacking. Here, by imaging light-driven glutamate release from more than 13,000 bipolar cell axon terminals in the intact retina, we show that bipolar cell functional diversity is generated by the interplay of dendritic excitatory inputs and axonal inhibitory inputs. The resulting centre and surround components of bipolar cell receptive fields interact to decorrelate bipolar cell output in the spatial and temporal domains. Our findings highlight the importance of inhibitory circuits in generating functionally diverse excitatory pathways and suggest that decorrelation of parallel visual pathways begins as early as the second synapse of the mouse visual system

    Transcriptome Analysis of Epithelial and Stromal Contributions to Mammogenesis in Three Week Prepartum Cows

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    Transcriptome analysis of bovine mammary development has provided insight into regulation of mammogenesis. However, previous studies primarily examined expression of epithelial and stromal tissues combined, and consequently did not account for tissue specific contribution to mammary development. Our objective was to identify differences in gene expression in epithelial and intralobular stromal compartments. Tissue was biopsied from non-lactating dairy cows 3 weeks prepartum, cut into explants and incubated for 2 hr with insulin and hydrocortisone. Epithelial and intralobular stromal tissues were isolated with laser capture microdissection. Global gene expression was measured with Bovine Affymetrix GeneChips, and data were preprocessed using RMA method. Moderated t-tests from gene-specific linear model analysis with cell type as a fixed effect showed more than 3,000 genes were differentially expressed between tissues (P<0.05; FDR<0.17). Analysis of epithelial and stromal transcriptomes using Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathways Analysis (IPA) showed that epithelial and stromal cells contributed distinct molecular signatures. Epithelial signatures were enriched with gene sets for protein synthesis, metabolism and secretion. Stromal signatures were enriched with genes that encoded molecules important to signaling, extracellular matrix composition and remodeling. Transcriptome differences also showed evidence for paracrine interactions between tissues in stimulation of IGF1 signaling pathway, stromal reaction, angiogenesis, neurogenesis, and immune response. Molecular signatures point to the dynamic role the stroma plays in prepartum mammogenesis and highlight the importance of examining the roles of cell types within the mammary gland when targeting therapies and studying mechanisms that affect milk production

    Negative attitudes related to violence against women: gender and ethnic differences among youth living in Serbia

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    OBJECTIVES: This study aimed to identify to what extent negative attitudes towards intimate partner violence against women are present among young women and men living in Serbia, in Roma and non-Roma settlements. METHODS: We used the data from the 2010 Multiple Indicator Cluster Survey conducted in Serbia, for the respondents who were 15-24 years old. Regression analyses were used to examine the association between judgmental attitudes, socio-demographic factors and life satisfaction. RESULTS: In Roma settlements, 34.8% of men and 23.6% of women believed that under certain circumstances men are justified to be violent towards wives, while among non-Roma it was 5.6 and 4.0%, respectively. These negative attitudes were significantly associated with lower educational level, lower socio-economic status and being married. In multivariate model, in both Roma and non-Roma population women who were not married were less judgmental, while the richest Roma men were least judgmental (OR 0.40, 95% CI 0.18-0.87). CONCLUSIONS: Violence prevention activities have to be focused on promoting gender equality among youth in vulnerable population groups such as Roma, especially through social support, strengthening their education and employment

    Staphylococcal Toxic Shock Syndrome 2000–2006: Epidemiology, Clinical Features, and Molecular Characteristics

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    Circulating strains of Staphylococcus aureus (SA) have changed in the last 30 years including the emergence of community-associated methicillin-resistant SA (MRSA). A report suggested staphylococcal toxic shock syndrome (TSS) was increasing over 2000-2003. The last population-based assessment of TSS was 1986.Population-based active surveillance for TSS meeting the CDC definition using ICD-9 codes was conducted in the Minneapolis-St. Paul area (population 2,642,056) from 2000-2006. Medical records of potential cases were reviewed for case criteria, antimicrobial susceptibility, risk factors, and outcome. Superantigen PCR testing and PFGE were performed on available isolates from probable and confirmed cases.Of 7,491 hospitalizations that received one of the ICD-9 study codes, 61 TSS cases (33 menstrual, 28 non-menstrual) were identified. The average annual incidence per 100,000 of all, menstrual, and non-menstrual TSS was 0.52 (95% CI, 0.32-0.77), 0.69 (0.39-1.16), and 0.32 (0.12-0.67), respectively. Women 13-24 years had the highest incidence at 1.41 (0.63-2.61). No increase in incidence was observed from 2000-2006. MRSA was isolated in 1 menstrual and 3 non-menstrual cases (7% of TSS cases); 1 isolate was USA400. The superantigen gene tst-1 was identified in 20 (80%) of isolates and was more common in menstrual compared to non-menstrual isolates (89% vs. 50%, p = 0.07). Superantigen genes sea, seb and sec were found more frequently among non-menstrual compared to menstrual isolates [100% vs 25% (p = 0.4), 60% vs 0% (p<0.01), and 25% vs 13% (p = 0.5), respectively].TSS incidence remained stable across our surveillance period of 2000-2006 and compared to past population-based estimates in the 1980s. MRSA accounted for a small percentage of TSS cases. tst-1 continues to be the superantigen associated with the majority of menstrual cases. The CDC case definition identifies the most severe cases and has been consistently used but likely results in a substantial underestimation of the total TSS disease burden

    Impact of community-based interventions on condom use in the Tłįchǫ region of Northwest Territories, Canada

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    <p>Abstract</p> <p>Background</p> <p>Since 2005, the Tłįchǫ Community Services Agency (TCSA) in Canada's Northwest Territories (NT) has addressed rising rates of sexually transmitted infections (STI). In 2009, STI rates in the NT were ten times higher than the national rate and Tłįchǫ regional rates were nearly four times that of the NT – 91 cases per 1000 people. We describe a social audit process that assessed the impact of an evidence-based community-led intervention.</p> <p>Methods</p> <p>A baseline survey of sexual health knowledge, attitudes and behaviours in 2006/07 provided evidence for a Community Action Research Team (CART) to develop and to put in place culturally appropriate interventions in the Tłįchǫ region. A follow-up study in 2010 sought to assess the impact of CART activities on condom use and underlying conscious knowledge, attitudes, subjective norms, intention to change, sense of agency and discussions related to condom use and STI risks. We report the contrasts using Odds Ratios (OR) and 95% confidence intervals (CI).</p> <p>Results</p> <p>One in every three follow-up respondents (315/808) participated in at least one CART activity. Participation in highly ranked interventions was associated with increased condom use during the last sexual encounter (OR 1.45, 95%CI 1.07-1.98). Those exposed to three or more activities were more likely to talk openly about condoms (OR 2.08, 95%CI 1.41-3.28), but were also less likely to be monogamous (OR 0.49, 95%CI 0.29-0.90).</p> <p>Conclusions</p> <p>The measurable impact on condom use indicates a strong beginning for the Tłįchǫ community intervention programmes. The interventions also seem to generate increased discussion, often a precursor to action. The Tłįchǫ can use the evidence to improve and refocus their programming, increase knowledge and continue to improve safe condom use practices.</p

    Blood pressure self-monitoring in pregnancy (BuMP) feasibility study; a qualitative analysis of women's experiences of self-monitoring

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    Background Hypertensive disorders in pregnancy are a leading cause of maternal and fetal morbidity worldwide. Raised blood pressure (BP) affects 10% of pregnancies worldwide, of which almost half develop pre-eclampsia. The proportion of pregnant women who have risk factors for pre-eclampsia (such as pre-existing hypertension, obesity and advanced maternal age) is increasing. Pre-eclampsia can manifest itself before women experience symptoms and can develop between antenatal visits. Incentives to improve early detection of gestational hypertensive disorders are therefore strong and self-monitoring of blood pressure (SMBP) in pregnancy might be one means to achieve this, whilst improving women’s involvement in antenatal care. The Blood Pressure Self-Monitoring in Pregnancy (BuMP) study aimed to evaluate the feasibility and acceptability of SMBP in pregnancy. Methods To understand women’s experiences of SMBP during pregnancy, we undertook a qualitative study embedded within the BuMP observational feasibility study. Women who were at higher risk of developing hypertension and/or pre-eclampsia were invited to take part in a study using SMBP and also invited to take part in an interview. Semi-structured interviews were conducted at the women’s homes in Oxfordshire and Birmingham with women who were self-monitoring their BP as part of the BuMP feasibility study in 2014. Interviews were conducted by a qualitative researcher and transcribed verbatim. A framework approach was used for analysis. Results Fifteen women agreed to be interviewed. Respondents reported general willingness to engage with monitoring their own BP, feeling that it could reduce anxiety around their health during pregnancy, particularly if they had previous experience of raised BP or pre-eclampsia. They felt able to incorporate self-monitoring into their weekly routines, although this was harder post-partum. Self-monitoring of BP made them more aware of the risks of hypertension and pre-eclampsia in pregnancy. Feelings of reassurance and empowerment were commonly reported by the women in our sample

    On the importance of long-term functional assessment after stroke to improve translation from bench to bedside

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    Despite extensive research efforts in the field of cerebral ischemia, numerous disappointments came from the translational step. Even if experimental studies showed a large number of promising drugs, most of them failed to be efficient in clinical trials. Based on these reports, factors that play a significant role in causing outcome differences between animal experiments and clinical trials have been identified; and latest works in the field have tried to discard them in order to improve the scope of the results. Nevertheless, efforts must be maintained, especially for long-term functional evaluations. As observed in clinical practice, animals display a large degree of spontaneous recovery after stroke. The neurological impairment, assessed by basic items, typically disappears during the firsts week following stroke in rodents. On the contrary, more demanding sensorimotor and cognitive tasks underline other deficits, which are usually long-lasting. Unfortunately, studies addressing such behavioral impairments are less abundant. Because the characterization of long-term functional recovery is critical for evaluating the efficacy of potential therapeutic agents in experimental strokes, behavioral tests that proved sensitive enough to detect long-term deficits are reported here. And since the ultimate goal of any stroke therapy is the restoration of normal function, an objective appraisal of the behavioral deficits should be done
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