Vitamin D receptor ChIP-seq in primary CD4+ cells: relationship to serum 25-hydroxyvitamin D levels and autoimmune disease

PMCID: PMC3710212This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Prevalence of Chlamydia trachomatis infection among women in a Middle Eastern community

BACKGROUND: Common vaginal infections that manifest in women are usually easily diagnosed. However, Chlamydia infection is often asymptomatic, leading to infertility before it is detected. If it occurs in pregnancy, it could lead to significant neonatal morbidity. It may also play a role with other viral infections for e.g. Human Papilloma Virus in the development of cervical cancer. The objective of this study was to determine the prevalence of Chlamydia infection in women undergoing screening for cervical abnormalities as a part of a research project in primary and secondary care institutions in the United Arab Emirates. METHODS: In this cross sectional study married women attending primary and secondary care participating in a large nationwide cervical abnormalities screening survey were offered Chlamydia testing using a commercially available test kit. This kit uses a rapid immunoassay for the direct detection of Chlamydia trachomatis antigen in endocervical swab specimens. As this study was performed in a traditional Islamic country, unmarried women were excluded from testing, as the management of any positive cases would create legal and social problems. All married women consenting to take part in the study were included irrespective of age. RESULTS: Of 1039 women approached over a period of eight months 919 (88.5%) agreed to participate. The number of women in the 16 to 19 years was small (0.01%) and 30% were aged over 40 years. The prevalence of Chlamydia infection in this study was 2.6% (95% confidence interval 1.2–3.3%), which was marginally higher in women screened in secondary care (p = 0.05). CONCLUSION: This is one of the few reports on the prevalence of Chlamydia infection in women from the Middle East. Due to cultural and social constraints this study excluded a large proportion of women aged less than 19 years of age. Hence no direct comparisons on prevalence could be made with studies from the West, which all included younger women at high risk of Chlamydia. However this study emphasizes the importance of cultural factors while interpreting results of studies from different cultures and communities

A Dynamic Model of Interactions of Ca^(2+), Calmodulin, and Catalytic Subunits of Ca^(2+)/Calmodulin-Dependent Protein Kinase II

During the acquisition of memories, influx of Ca^(2+) into the postsynaptic spine through the pores of activated N-methyl-D-aspartate-type glutamate receptors triggers processes that change the strength of excitatory synapses. The pattern of Ca^(2+) influx during the first few seconds of activity is interpreted within the Ca^(2+)-dependent signaling network such that synaptic strength is eventually either potentiated or depressed. Many of the critical signaling enzymes that control synaptic plasticity, including Ca^(2+)/calmodulin-dependent protein kinase II (CaMKII), are regulated by calmodulin, a small protein that can bind up to 4 Ca^(2+) ions. As a first step toward clarifying how the Ca^(2+)-signaling network decides between potentiation or depression, we have created a kinetic model of the interactions of Ca^(2+), calmodulin, and CaMKII that represents our best understanding of the dynamics of these interactions under conditions that resemble those in a postsynaptic spine. We constrained parameters of the model from data in the literature, or from our own measurements, and then predicted time courses of activation and autophosphorylation of CaMKII under a variety of conditions. Simulations showed that species of calmodulin with fewer than four bound Ca^(2+) play a significant role in activation of CaMKII in the physiological regime, supporting the notion that processing ofCa^(2+) signals in a spine involves competition among target enzymes for binding to unsaturated species of CaM in an environment in which the concentration of Ca^(2+) is fluctuating rapidly. Indeed, we showed that dependence of activation on the frequency of Ca^(2+) transients arises from the kinetics of interaction of fluctuating Ca^(2+) with calmodulin/CaMKII complexes. We used parameter sensitivity analysis to identify which parameters will be most beneficial to measure more carefully to improve the accuracy of predictions. This model provides a quantitative base from which to build more complex dynamic models of postsynaptic signal transduction during learning

Bone mineral density in Jamaican men on androgen deprivation therapy for prostate cancer

<p>Abstract</p> <p>Background</p> <p>Androgen deprivation therapy (ADT) has been reported to reduce the bone mineral density (BMD) in men with prostate cancer (CaP). However, Afro-Caribbeans are under-represented in most studies. The aim was to determine the effect of androgen deprivation therapy (ADT) on the bone mineral density (BMD) of men with prostate cancer in Jamaica.</p> <p>Methods</p> <p>The study consisted of 346 Jamaican men, over 40 years of age: 133 ADT treated CaP cases (group 1), 43 hormone-naïve CaP controls (group 2) and 170 hormone naïve controls without CaP (group 3). Exclusion criteria included metastatic disease, bisphosphonate therapy or metabolic disease affecting BMD. BMD was measured with a calcaneal ultrasound and expressed in S.D. units relative to young adult men (T score), according to the World Health Organization definition. Patient weight, height and BMI were assessed.</p> <p>Results</p> <p>Mean ± sd, age of patients in group 1 (75± 7.4 yrs) was significantly greater than groups 2 and 3 (67 ± 8.1 yrs; 65±12.0 yrs). There was no significant difference in weight and BMI between the 3 groups. . The types of ADT (% of cases, median duration in months with IQR) included LHRH (Luteinizing hormone releasing hormone) analogues (28.6%, 17.9, IQR 20.4), oestrogens (9.8%, 60.5, IQR 45.6) anti-androgens (11.3%, 3.3, IQR 15.2) and orchiectomy (15.7%, 43.4, IQR 63.9). Unadjusted t score of group 1, mean ± sd, (-1.6± 1.5) was significantly less than group 2 (-0.9±1.1) and group 3 (-0.7±1.4), p <0.001. Ninety three (69.9%), 20 (45%) and 75 (42%) of patients in groups 1, 2 and 3 respectively were classified as either osteopenic or osteoporotic (p<0.001). Adjusting for age, there was a significant difference in t scores between groups 1 and 2 as well as between groups 1 and 3 (p<0.001). Compared with oestrogen therapy and adjusting for duration of therapy, the odds of low bone mineral density (osteopenia or osteoporosis) with LHRH analogue was 4.5 (95%CI, 14.3 to 3.4); with anti-androgens was 5.9 (95%CI, 32.7 to 5); with orchiectomy was 7.3 (95%CI, 30 to 5.8) and multiple drugs was 9.2 ((95%CI, 31 to 7.1).</p> <p>Conclusions</p> <p>ADT is associated with lower BMD in Jamaican men on hormonal therapy for prostate cancer.</p

Loss of Expression and Promoter Methylation of SLIT2 Are Associated with Sessile Serrated Adenoma Formation.

Serrated adenomas form a distinct subtype of colorectal pre-malignant lesions that may progress to malignancy along a different molecular pathway than the conventional adenoma-carcinoma pathway. Previous studies have hypothesised that BRAF mutation and promoter hypermethylation plays a role, but the evidence for this is not robust. We aimed to carry out a whole-genome loss of heterozygosity analysis, followed by targeted promoter methylation and expression analysis to identify potential pathways in serrated adenomas. An initial panel of 9 sessile serrated adenomas (SSA) and one TSA were analysed using Illumina Goldengate HumanLinkage panel arrays to ascertain regions of loss of heterozygosity. This was verified via molecular inversion probe analysis and microsatellite analysis of a further 32 samples. Methylation analysis of genes of interest was carried out using methylation specific PCR (verified by pyrosequencing) and immunohistochemistry used to correlate loss of expression of genes of interest. All experiments used adenoma samples and normal tissue samples as control. SSA samples were found on whole-genome analysis to have consistent loss of heterozygosity at 4p15.1–4p15.31, which was not found in the sole TSA, adenomas, or normal tissues. Genes of interest in this region were PDCH7 and SLIT2, and combined MSP/IHC analysis of these genes revealed significant loss of SLIT2 expression associated with promoter methylation of SLIT2. Loss of expression of SLIT2 by promoter hypermethylation and loss of heterozygosity events is significantly associated with serrated adenoma development, and SLIT2 may represent a epimutated tumour suppressor gene according to the Knudson “two hit” hypothesis

HIV Risk Profiles Among HIV-Positive, Methamphetamine-Using Men Who Have Sex with Both Men and Women

This study examined demographic characteristics, sexual risk behaviors, sexual beliefs, and substance use patterns in HIV-positive, methamphetamine-using men who have sex with both men and women (MSMW) (n = 50) as compared to men who have sex with men only (MSM) (n = 150). Separate logistic regressions were conducted to predict group membership. In the final model, of 12 variables, eight were independently associated with group membership. Factors independently associated with MSMW were acquiring HIV through injection drug use, being an injection drug user, using hallucinogens, using crack, being less likely to have sex at a bathhouse, being less likely to be the receptive partner when high on methamphetamine, having greater intentions to use condoms for oral sex, and having more negative attitudes about HIV disclosure. These results suggest that, among HIV-positive methamphetamine users, MSMW differ significantly from MSM in terms of their HIV risk behaviors. Studies of gay men and HIV often also include bisexual men, grouping them all together as MSM, which may obscure important differences between MSMW and MSM. It is important that future studies consider MSM and MSMW separately in order to expand our knowledge about differential HIV prevention needs for both groups. This study showed that there were important differences in primary and secondary prevention needs of MSM and MSMW. These findings have implications for both primary and secondary HIV prevention among these high-risk populations

Structural basis for VPS34 kinase activation by Rab1 and Rab5 on membranes.

The lipid phosphatidylinositol-3-phosphate (PI3P) is a regulator of two fundamental but distinct cellular processes, endocytosis and autophagy, so its generation needs to be under precise temporal and spatial control. PI3P is generated by two complexes that both contain the lipid kinase VPS34: complex II on endosomes (VPS34/VPS15/Beclin 1/UVRAG), and complex I on autophagosomes (VPS34/VPS15/Beclin 1/ATG14L). The endosomal GTPase Rab5 binds complex II, but the mechanism of VPS34 activation by Rab5 has remained elusive, and no GTPase is known to bind complex I. Here we show that Rab5a-GTP recruits endocytic complex II to membranes and activates it by binding between the VPS34 C2 and VPS15 WD40 domains. Electron cryotomography of complex II on Rab5a-decorated vesicles shows that the VPS34 kinase domain is released from inhibition by VPS15 and hovers over the lipid bilayer, poised for catalysis. We also show that the GTPase Rab1a, which is known to be involved in autophagy, recruits and activates the autophagy-specific complex I, but not complex II. Both Rabs bind to the same VPS34 interface but in a manner unique for each. These findings reveal how VPS34 complexes are activated on membranes by specific Rab GTPases and how they are recruited to unique cellular locations

Purkinje cell input to cerebellar nuclei in tottering: Ultrastructure and physiology

Homozygous tottering mice are spontaneous ataxic mutants, which carry a mutation in the gene encoding the ion pore of the P/Q-type voltage-gated calcium channels. P/Q-type calcium channels are prominently expressed in Purkinje cell terminals, but it is unknown to what extent these inhibitory terminals in tottering mice are affected at the morphological and electrophysiological level. Here, we investigated the distribution and ultrastructure of their Purkinje cell terminals in the cerebellar nuclei as well as the activities of their target neurons. The densities of Purkinje cell terminals and their synapses were not significantly affected in the mutants. However, the Purkinje cell terminals were enlarged and had an increased number of vacuoles, whorled bodies, and mitochondria. These differences started to occur between 3 and 5 weeks of age and persisted throughout adulthood. Stimulation of Purkinje cells in adult tottering mice resulted in inhibition at normal latencies, but the activities of their postsynaptic neurons in the cerebellar nuclei were abnormal in that the frequency and irregularity of their spiking patterns were enhanced. Thus, although the number of their terminals and their synaptic contacts appear quantitatively intact, Purkinje cells in tottering mice show several signs of axonal damage that may contribute to altered postsynaptic activities in the cerebellar nuclei

Transport of Anthocyanins and other Flavonoids by the Arabidopsis ATP-Binding Cassette Transporter AtABCC2

Flavonoids have important developmental, physiological, and ecological roles in plants and are primarily stored in the large central vacuole. Here we show that both an ATP-binding cassette (ABC) transporter(s) and an H+-antiporter(s) are involved in the uptake of cyanidin 3-O-glucoside (C3G) by Arabidopsis vacuolar membrane-enriched vesicles. We also demonstrate that vesicles isolated from yeast expressing the ABC protein AtABCC2 are capable of MgATP-dependent uptake of C3G and other anthocyanins. The uptake of C3G by AtABCC2 depended on the co-transport of glutathione (GSH). C3G was not altered during transport and a GSH conjugate was not formed. Vesicles from yeast expressing AtABCC2 also transported flavone and flavonol glucosides. We performed ligand docking studies to a homology model of AtABCC2 and probed the putative binding sites of C3G and GSH through site-directed mutagenesis and functional studies. These studies identified residues important for substrate recognition and transport activity in AtABCC2, and suggest that C3G and GSH bind closely, mutually enhancing each other’s binding. In conclusion, we suggest that AtABCC2 along with possibly other ABCC proteins are involved in the vacuolar transport of anthocyanins and other flavonoids in the vegetative tissue of Arabidopsis