275 research outputs found

    Identification of novel inhibitors of auxin-induced Ca2+ signaling via a plant-based chemical screen

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    Many signal perception mechanisms are connected to Ca2+-based second messenger signaling to modulate specific cellular responses. The well-characterized plant hormone auxin elicits a very rapid Ca2+ signal. However, the cellular targets of auxin-induced Ca2+ are largely unknown. Here, we screened a biologically annotated chemical library for inhibitors of auxin-induced Ca2+ entry in plant cell suspensions to better understand the molecular mechanism of auxin-induced Ca2+ and to explore the physiological relevance of Ca2+ in auxin signal transduction. Using this approach, we defined a set of diverse, small molecules that interfere with auxin-induced Ca2+ entry. Based on annotated biological activities of the hit molecules, we found that auxin-induced Ca2+ signaling is, among others, highly sensitive to disruption of membrane proton gradients and the mammalian Ca2+ channel inhibitor bepridil. Whereas protonophores nonselectively inhibited auxin-induced and osmotic-stress-induced Ca2+ signals, bepridil specifically inhibited auxin-induced Ca2+. We found evidence that bepridil severely alters vacuolar morphology and antagonized auxin-induced vacuolar remodeling. Further exploration of this plant-tailored collection of inhibitors will lead to a better understanding of auxin-induced Ca2+ entry and its relevance for auxin responses

    Implementation of an interprofessional medication adherence program for HIV patients: description of the process using the framework for the implementation of services in pharmacy.

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    The community pharmacy center of the Department of Ambulatory Care and Community Medicine of the Policlinique Médicale Universitaire (PMU), Lausanne, Switzerland developed and implemented an interprofessional medication adherence program for chronic patients (IMAP). In 2014, a project was launched to implement the IMAP for HIV patients in a public non-academic hospital with the collaboration of community pharmacists in the Neuchâtel area (Switzerland). This article aims to describe the different implementation stages and strategies of the project. A posteriori description of the implementation process, including the conceptualization strategies and stages (exploration, preparation, operation, sustainability) using the Framework for the Implementation of Services in Pharmacy (FISpH). In 2014, an attending infectious disease physician and a nurse at a public hospital (Neuchâtel, Switzerland) contacted the PMU to implement the IMAP in their setting in collaboration with community pharmacies. Five volunteer community pharmacies in Neuchâtel were trained to deliver the program. Three factors were found to be essential to the successful launch and progress of the implementation project: the experience of the community pharmacy center of the PMU with the IMAP, the involvement of the PMU research team, and collaboration with an external start up (SISPha) to train and support pharmacists. During the operation stage, the most important strategy developed was that of regular meetings between all stakeholders. These allowed healthcare professionals to discuss the implementation progress, to address each stakeholder's expectations, and to exchange experiences to facilitate interprofessional collaboration and program delivery. Structural changes allowed the formalization of the activities at the hospital and in a community pharmacy. This formalization was identified as the transition step between the operation and the sustainability stages. The transfer of the IMAP for HIV patients to a non-academic setting and its implementation are feasible. However, implementation of a new model of pharmacy service such as IMAP implies a deep change in practice. A transitional external support and the allocation of sufficient resources to carry out the IMAP are essential for its long-term sustainability

    Assessment of medication adherence and responsible use of isotretinoin and contraception through Belgian community pharmacies by using pharmacy refill data.

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    The aims of the study were to evaluate medication adherence and the influencing factors for isotretinoin and contraception (oral, patches, and rings) and to evaluate the concomitant use of contraception and isotretinoin. Reimbursed prescription data from January 2012 to August 2015 of all patients in Belgium were received from Pharmanet-National Institute for Health and Disability Insurance. Medication adherence was measured according to the medication possession ratio. The influence of gender and age was analyzed using the Mann-Whitney test and the Spearman coefficient correlation. The independence between adherence to contraception and adherence to isotretinoin was analyzed using the Pearson chi-square test of independence. Persistence was defined as the number of days between initiation and presumed end of treatment. The Kaplan-Meier method was used to plot the medication persistence curves, and the log-rank test was used to compare the curves. The concomitant use of contraception and isotretinoin was analyzed using descriptive statistics. The medication possession ratio was ≥0.8 for 46.1% of patients receiving isotretinoin and for 74.0% of women using contraception. For isotretinoin, this percentage decreased as the number of attempts increased (29.8% for the second attempt and 19.8% for more than two attempts). Men seemed more adherent than women, and a weak negative correlation between adherence and age was observed. The adherence data of isotretinoin and contraception were independent. The median persistence for isotretinoin treatment was 139 days (interquartile range 71-209) and was higher for men. Among women between 12 and 21 years old taking isotretinoin, 63.8% received at least one contraceptive prescription. However, 15.7% of women taking isotretinoin adhered to the use of contraception 1 month before, during, and 1 month after treatment. Medication adherence to isotretinoin and contraception and compliance with the isotretinoin safety recommendation could be improved. Health service interventions, using pharmacy refill data, should be delivered to ensure patient safety and strict adherence to contraception when under isotretinoin treatment

    Abdominal aortic calcification on a plain X-ray and the relation with significant coronary artery disease in asymptomatic chronic dialysis patients

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    BACKGROUND: Coronary artery disease (CAD) is common in asymptomatic chronic dialysis patients and plays an important role in their poor survival. Early identification of these high-risk patients could improve treatment and reduce mortality. Abdominal aortic calcification (AAC) has previously been associated with CAD in autopsy studies. Since the AAC can be quantified easily using a lateral lumbar X-ray we hypothesized that the extent of AAC as assessed on a lateral lumbar X-ray might be predictive of the presence of significant CAD in dialysis patients. METHODS: All patients currently enrolled in the ICD2 trial without a history of CABG or a PCI with stent implantation were included in this study. All patients underwent CT-angiography (CTA) and a lateral X-ray of the abdomen. AAC on X-ray was quantified using a previously validated scoring system whereupon the association between AAC and the presence of significant CAD was assessed. RESULTS: A total of 90 patients were included in this study (71% male, 67 ± 7 years old). Forty-six patients were found to have significant CAD. AAC-score was significantly higher in patients with CAD (10.1 ± 4.9 vs 6.3 ± 4.6 (p < 0.05). Multivariate regression analysis revealed that AAC score is an independent predictor for the presence of CAD with a 1,2 fold higher risk per point increase (p < 0.01). The AAC score has a sensitivity of 85% and a specificity of 57% for the presence of significant CAD. CONCLUSION: This study shows that abdominal aortic calcification as assessed on a lateral lumbar X-ray is predictive for the presence of significant coronary artery disease in asymptomatic dialysis patients. This simple, non-invasive and cheap screening method could contribute to early identification of patients eligible for further screening of CAD. TRIAL REGISTRATION: NTR948, registered 10-4-2007 ; ISRCTN20479861, registered 2-5-200

    Use of a food frequency questionnaire in American Indian and Caucasian pregnant women: a validation study

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    BACKGROUND: Food frequency questionnaires (FFQs) have been validated in pregnant women, but few studies have focused specifically on low-income women and minorities. The purpose of this study was to examine the validity of the Harvard Service FFQ (HSFFQ) among low-income American Indian and Caucasian pregnant women. METHODS: The 100-item HSFFQ was administered three times to a sample of pregnant women, and two sets of 24-hour recalls (six total) were collected at approximately 12 and 28 weeks of gestation. The sample included a total of 283 pregnant women who completed Phase 1 of the study and 246 women who completed Phase 2 of the study. Deattenuated Pearson correlation coefficients were used to compare intakes of 24 nutrients estimated from the second and third FFQ to average intakes estimated from the week-12 and week-28 sets of diet recalls. RESULTS: Deattenuated correlations ranged from 0.09 (polyunsaturated fat) to 0.67 (calcium) for Phase 1 and from 0.27 (sucrose) to 0.63 (total fat) for Phase 2. Average deattenuated correlations for the two phases were 0.48 and 0.47, similar to those reported among other groups of pregnant women. CONCLUSION: The HSFFQ is a simple self-administered questionnaire that is useful in classifying low-income American Indian and Caucasian women according to relative dietary intake during pregnancy. Its use as a research tool in this population may provide important information about associations of nutrient intakes with pregnancy outcomes and may help to identify groups of women who would benefit most from nutritional interventions

    Enzymatic Characterization of a Human Acyltransferase Activity

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    Non-histone protein acylation is increasingly recognized as an important posttranslational modification, but little is known as to the biochemical properties of protein serine acylating enzymes.We here report that we have identified a metal-stimulated serine octanoyltransferase activity in microsomes from human erythroleukemic (HEL) cells. The HEL acylating enzyme was linear with respect to time and protein, exhibited a neutral pH optimum (stimulated by cobalt and zinc), and inhibited by chelating reagents. Hydroxylamine treatment removed most, but not all, of the attached radioactivity. A salt extract of microsomal membranes contained the major portion of enzyme activity, indicating that this acyltransferase is not an integral membrane protein. Sucrose density fractionation showed that the acyltransferase activity is concentrated in the endoplasmic reticulum. In competition experiments, the acyltransferase was well inhibited by activated forms of fatty acids containing at least eight to fourteen carbons, but not by acetyl CoA. The zinc-stimulated HEL acyltransferase did not octanoylate proenkephalin, proopiomelanocortin, His-tagged proghrelin, or proghrelin lacking the amino-terminal His-tag stub of Gly-Ala-Met. The peptides des-acyl ghrelin and ACTH were also not acylated; however, des-acyl ghrelin containing the N-terminal tripeptide Gly-Ala-Met was acylated. Mutagenesis studies indicated a requirement for serine five residues from the amino terminus, reminiscent of myristoyl transferase, but not of ghrelin acylation. However, recombinant myristoyl transferase could not recapitulate the hydroxylamine sensitivity, zinc-stimulation, nor EDTA inhibition obtained with HEL acyltransferase, properties preserved in the HEL cell enzyme purified through four sequential chromatographic steps.In conclusion, our data demonstrate the presence of a zinc-stimulated acyltransferase activity concentrated in the endoplasmic reticulum in HEL cells which is likely to contribute to medium-chain protein lipidation

    Fats and Factors: Lipid Profiles Associate with Personality Factors and Suicidal History in Bipolar Subjects

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    Polyunsaturated fatty acids (PUFA) have shown efficacy in the treatment of bipolar disorder, however their specific role in treating the illness is unclear. Serum PUFA and dietary intakes of PUFA associate with suicidal behavior in epidemiological studies. The objective of this study was to assess serum n-3 and n-6 PUFA levels in bipolar subjects and determine possible associations with suicidal risk, including suicidal history and relevant personality factors that have been associated with suicidality. We studied 27 bipolar subjects using the NEO-PI to assess the big five personality factors, structured interviews to verify diagnosis and assess suicidal history, and lipomics to quantify n-3 and n-6 PUFA in serum. We found positive associations between personality factors and ratios of n-3 PUFA, suggesting that conversion of short chain to long chain n-3s and the activity of enzymes in this pathway may associate with measures of personality. Thus, ratios of docosahexaenoic acid (DHA) to alpha linolenic acid (ALA) and the activity of fatty acid desaturase 2 (FADS2) involved in the conversion of ALA to DHA were positively associated with openness factor scores. Ratios of eicosapentaenoic acid (EPA) to ALA and ratios of EPA to DHA were positively associated with agreeableness factor scores. Finally, serum concentrations of the n-6, arachidonic acid (AA), were significantly lower in subjects with a history of suicide attempt compared to non-attempters. The data suggest that specific lipid profiles, which are controlled by an interaction between diet and genetics, correlate with suicidal history and personality factors related to suicidal risk. This study provides preliminary data for future studies to determine whether manipulation of PUFA profiles (through diet or supplementation) can affect personality measures and disease outcome in bipolar subjects and supports the need for further investigations into individualized specific modulations of lipid profiles to add adjunctive value to treatment paradigms
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