105 research outputs found

    IL-7 promotes T cell proliferation through destabilization of p27Kip1

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    Interleukin (IL)-7 is required for survival and homeostatic proliferation of T lymphocytes. The survival effect of IL-7 is primarily through regulation of Bcl-2 family members; however, the proliferative mechanism is unclear. It has not been determined whether the IL-7 receptor actually delivers a proliferative signal or whether, by promoting survival, proliferation results from signals other than the IL-7 receptor. We show that in an IL-7–dependent T cell line, cells protected from apoptosis nevertheless underwent cell cycle arrest after IL-7 withdrawal. This arrest was accompanied by up-regulation of the cyclin-dependent kinase inhibitor p27Kip1 through a posttranslational mechanism. Overexpression of p27Kip1 induced G1 arrest in the presence of IL-7, whereas knockdown of p27Kip1 by small interfering RNA promoted S phase entry after IL-7 withdrawal. CD4 or CD8 T cells transferred into IL-7–deficient hosts underwent G1 arrest, whereas 27Kip1-deficient T cells underwent proliferation. We observed that IL-7 withdrawal activated protein kinase C (PKC)θ and that inhibition of PKCθ with a pharmacological inhibitor completely blocked the rise of p27Kip1 and rescued cells from G1 arrest. The conventional pathway to breakdown of p27Kip1 is mediated by S phase kinase-associated protein 2; however, our evidence suggests that PKCθ acts via a distinct, unknown pathway inducing G1 arrest after IL-7 withdrawal from T cells. Hence, IL-7 maintains T cell proliferation through a novel pathway of p27Kip1 regulation

    Heterozygosity and fitness in a California population of the labyrinth spider Metepeira ventura (Araneae, Araneidae).

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    The relationship between individual heterozygosity and characteristics likely to be associated with fitness was investigated in the labyrinth spider Metepeira ventura. Adult females and their egg sacs were collected at a coastal site in southern California, and three measures of bodily condition (carapace width, weight, residual index) and six measures of reproductive output (number of egg sacs, variation in egg number among sacs [coefficient of variation], total number of eggs, mean eggs/sac, mean eggs/sac divided by carapace width, mean eggs/sac divided by weight) were determined for each spider. The sample was polymorphic at three allozyme loci that were in Hardy-Weinberg equilibrium, and individual females were heterozygous at up to two of the three loci, forming three heterozygosity classes (0, 1, and 2). None of the bodily condition measures were significantly related to the number of heterozygous loci, while four of the reproductive output estimators (total number of eggs, mean eggs/sac, mean eggs/sac divided by carapace width, mean eggs/sac divided by weight) were significantly influenced by heterozygosity. In each significant case, values for class 2 females were less than those for class 0 and 1 females, whose values were usually more similar. Thus, while female bodily condition was comparable among classes, the most heterozygous females produced fewer total eggs and eggs per sac than their less heterozygous peers. The fact that females of M. ventura engage in a reproductive investment-number trade-off suggests that high-variability and low-variability females may be pursuing distinct reproductive strategies in the wild, with more heterozygous females being K-selected (smaller clutches, heavier eggs) and more homozygous females being r-selected (larger clutches, lighter eggs). Further investigation will be needed to assess more fully the fitness value of heterozygosity in M. ventura

    Physical characterization and in vitro evaluation of some generic medications available in pharma market of United Arab Emirates (UAE)

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    This study is the first attempt in UAE to prove the trustworthiness of the in vitro evaluation to assess the reliability of the generic medications comparing to the brand name. Five generic medicines, two Local (codes: L1, L2), three Arabic (codes: A1, A2 and A3) and the International brand (code: I1) of diclofenac sodium (DS) sustained release tablets, as a model product, was collected randomly from the UAE pharma market. The products were characterized by physical parameters including weight variation, thickness, friability, hardness and moisture content. The in vitro release study was conducted in simulated gastric medium (0.1 N HCl, pH 1.2) for 2 h and simulated intestinal medium (phosphate buffer pH 6.8) for 9 h using type II (paddle type) USP reference dissolution apparatus. The drug was assayed by using UV spectrophotometry at 277 nm. Different kinetics models were applied to drug release data in order to evaluate mechanism of drug release. Physical properties of all products compiled with the acceptable limits. However moisture content was higher than the standard value in the generic products except the brand. All the products succeed to fulfill their official requirement of 80 % drug release within 8 h, in simulated intestinal medium except A3. Zero order release kinetics was predominant for al L2 and the International brand while more data fitting to Hixson- Crowell kinetics was obtained with the L1 and A1, A2 and A3. The results of our study question the suitability of the generic products as a replacement for the branded product. Therefore, we strongly suggest that evaluation on the marketed samples has to be made in order to establish bioequivalency between the branded and the generic products.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Ciliary Abnormalities Due to Defects in the Retrograde Transport Protein DYNC2H1 in Short-Rib Polydactyly Syndrome

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    The short-rib polydactyly (SRP) syndromes are a heterogenous group of perinatal lethal skeletal disorders with polydactyly and multisystem organ abnormalities. Homozygosity by descent mapping in a consanguineous SRP family identified a genomic region that contained DYNC2H1, a cytoplasmic dynein involved in retrograde transport in the cilium. Affected individuals in the family were homozygous for an exon 12 missense mutation that predicted the amino acid substitution R587C. Compound heterozygosity for one missense and one null mutation was identified in two additional nonconsanguineous SRP families. Cultured chondrocytes from affected individuals showed morphologically abnormal, shortened cilia. In addition, the chondrocytes showed abnormal cytoskeletal microtubule architecture, implicating an altered microtubule network as part of the disease process. These findings establish SRP as a cilia disorder and demonstrate that DYNC2H1 is essential for skeletogenesis and growth

    Challenges facing early career academic cardiologists

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    Early career academic cardiologists currently face unprecedented challenges that threaten a highly valued career path. A team consisting of early career professionals and senior leadership members of American College of Cardiology completed this white paper to inform the cardiovascular medicine profession regarding the plight of early career cardiologists and to suggest possible solutions. This paper includes: 1) definition of categories of early career academic cardiologists; 2) general challenges to all categories and specific challenges to each category; 3) obstacles as identified by a survey of current early career members of the American College of Cardiology; 4) major reasons for the failure of physician-scientists to receive funding from National Institute of Health/National Heart Lung and Blood Institute career development grants; 5) potential solutions; and 6) a call to action with specific recommendations

    The Impact of Clinical Pharmacist Diabetes Education on Medication Adherence in Patients with Type 2 Diabetes Mellitus: An Interventional Study from Khartoum, Sudan

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    Background: Continuous therapeutic care with good medication adherence is the cornerstone of management of all chronic diseases including diabetes. This study aimed to evaluate the impact of clinical pharmacist intervention on the medication adherence in individuals with type 2 diabetes (T2DM). Methods: This was a randomized, double-blind, controlled trial conducted at a diabetes clinic located at Omdurman Military Hospital, Sudan. Individuals with T2DM attending the diabetes clinic within 1 year were selected. The sample size was 364 participants (182 control and 182 interventional group). We used a pre-structured standardized questionnaire and checklist to collect the data. Data were analyzed by using the Statistical Package for the Social Sciences (SPSS) (version 28). Results: Majority, 76.4% (n = 278) were females, and they consisted of 80.8% (n = 147) of the interventional group and 72% of the controls. The mean age of the interventional group was 54.5 (±10) years; 31.9% (n = 58) of the interventional group had diabetes for 6–10 years, compared with 26.4% (n = 48) of the control group. Among the control group, the mean adherence score was 6.8 (±1.7) at baseline and it was 6.7 (±1.6) at the end of the study (p < 0.001), while in the interventional group, the mean adherence score was 6.8 (±1.7) at baseline and it was 7.4 (±1.5) at the end of the study (p < 0.001). Conclusion: Adherence score among the intervention group was increased significantly from baseline to the end of the study when compared to the control group.Scopu

    Patterns of tobacco use in the United Arab Emirates healthy future (UAEHFS) pilot study

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    © 2018 Al-Houqani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction Self-reported tobacco use in the United Arab Emirates is among the highest in the region. Use of tobacco products other than cigarettes is widespread, but little is known about specific behavior use patterns. There have been no studies that have biochemically verified smoking status. Methods The UAE Healthy Future Study (UAEHFS) seeks to understand the causes of non-communicable diseases through a 20,000-person cohort study. During the study pilot, 517 Emirati nationals were recruited to complete a questionnaire, provide clinical measurements and biological samples. Complete smoking data were available for 428 participants. Validation of smoking status via cotinine testing was conducted based on complete questionnaire data and matching urine samples for 399 participants, using a cut-off of 200ng/ml to indicate active smoking status. Results Self-reported tobacco use was 36% among men and 3% among women in the sample. However, biochemical verification of smoking status revealed that 42% men and 9% of women were positive for cotinine indicating possible recent tobacco use. Dual and poly-use of tobacco products was fairly common with 32% and 6% of the sample reporting respectively. Conclusions This is the first study in the region to biochemically verify tobacco use self-report data. Tobacco use in this study population was found to be higher than previously thought, especially among women. Misclassification of smoking status was more common than expected. Poly-tobacco use was also very common. Additional studies are needed to understand tobacco use behaviors and the extent to which people may be exposed to passive tobacco smoke. Implications This study is the first in the region to biochemically verify self-reported smoking status

    Types of tobacco consumption and the oral microbiome in the United Arab Emirates Healthy Future (UAEHFS) Pilot Study

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    © 2018, The Author(s). Cigarette smoking alters the oral microbiome; however, the effect of alternative tobacco products remains unclear. Middle Eastern tobacco products like dokha and shisha, are becoming globally widespread. We tested for the first time in a Middle Eastern population the hypothesis that different tobacco products impact the oral microbiome. The oral microbiome of 330 subjects from the United Arab Emirates Healthy Future Study was assessed by amplifying the bacterial 16S rRNA gene from mouthwash samples. Tobacco consumption was assessed using a structured questionnaire and further validated by urine cotinine levels. Oral microbiome overall structure and specific taxon abundances were compared, using PERMANOVA and DESeq analyses respectively. Our results show that overall microbial composition differs between smokers and nonsmokers (p = 0.0001). Use of cigarettes (p = 0.001) and dokha (p = 0.042) were associated with overall microbiome structure, while shisha use was not (p = 0.62). The abundance of multiple genera were significantly altered (enriched/depleted) in cigarette smokers; however, only Actinobacillus, Porphyromonas, Lautropia and Bifidobacterium abundances were significantly changed in dokha users whereas no genera were significantly altered in shisha smokers. For the first time, we show that smoking dokha is associated to oral microbiome dysbiosis, suggesting that it could have similar effects as smoking cigarettes on oral health

    The AGE-RAGE axis in an Arab population: The United Arab Emirates Healthy Futures (UAEHFS) pilot study

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    © 2017 The Authors Aims The transformation of the United Arab Emirates (UAE) from a semi-nomadic to a high income society has been accompanied by increasing rates of obesity and Type 2 diabetes mellitus. We examined if the AGE-RAGE (receptor for advanced glycation endproducts) axis is associated with obesity and diabetes mellitus in the pilot phase of the UAE Healthy Futures Study (UAEHFS). Methods 517 Emirati subjects were enrolled and plasma/serum levels of AGE, carboxy methyl lysine (CML)-AGE, soluble (s)RAGE and endogenous secretory (es)RAGE were measured along with weight, height, waist and hip circumference (WC/HC), blood pressure, HbA1c, Vitamin D levels and routine chemistries. The relationship between the AGE-RAGE axis and obesity and diabetes mellitus was tested using proportional odds models and linear regression. Results After covariate adjustment, AGE levels were significantly associated with diabetes status. Levels of sRAGE and esRAGE were associated with BMI and levels of sRAGE were associated with WC/HC. Conclusions The AGE-RAGE axis is associated with diabetes status and obesity in this Arab population. Prospective serial analysis of this axis may identify predictive biomarkers of obesity and cardiometabolic dysfunction in the UAEHFS

    Incense Burning is Associated with Human Oral Microbiota Composition

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    © 2019, The Author(s). Incense burning is common worldwide and produces environmental toxicants that may influence health; however, biologic effects have been little studied. In 303 Emirati adults, we tested the hypothesis that incense use is linked to compositional changes in the oral microbiota that can be potentially significant for health. The oral microbiota was assessed by amplification of the bacterial 16S rRNA gene from mouthwash samples. Frequency of incense use was ascertained through a questionnaire and examined in relation to overall oral microbiota composition (PERMANOVA analysis), and to specific taxon abundances, by negative binomial generalized linear models. We found that exposure to incense burning was associated with higher microbial diversity (p \u3c 0.013) and overall microbial compositional changes (PERMANOVA, p = 0.003). Our study also revealed that incense use was associated with significant changes in bacterial abundances (i.e. depletion of the dominant taxon Streptococcus), even in occasional users (once/week or less) implying that incense use impacts the oral microbiota even at low exposure levels. In summary, this first study suggests that incense burning alters the oral microbiota, potentially serving as an early biomarker of incense-related toxicities and related health consequences. Although a common indoor air pollutant, guidelines for control of incense use have yet to be developed
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