‘If she is a good woman …’ and ‘to be a real man …’: gender,risk and access to HIV services among key populations in Tajikistan

The HIV epidemic continues to grow in Tajikistan, especially among people who inject drugs, sex workers, men who have sex with men and incarcerated populations. Despite their susceptibility to HIV, members of these groups do not always have access to HIV prevention, testing and treatment. The purpose of this study was to identify and understand the gender constraints in accessing HIV services for key populations in Tajikistan. Using focus-group discussions and key-informant interviews the assessment team collected information from members of key populations and those who work with them. Several themes emerged from the data, including: low levels of HIV knowledge, gender constraints to condom use and safer drug use, gender constraints limit HIV testing opportunities, gender-based violence, stigma and discrimination, and the lack of female spaces in the HIV response. The results of this study show that there are well-defined gender norms in Tajikistan, and these gender norms influence key populations’ access to HIV services. Addressing these gender constraints may offer opportunities for more equitable access to HIV services in Tajikistan.     

Tissue folding at the organ–meristem boundary results in nuclear compression and chromatin compaction

Artificial mechanical perturbations affect chromatin in animal cells in culture. Whether this is also relevant to growing tissues in living organisms remains debated. In plants, aerial organ emergence occurs through localized outgrowth at the periphery of the shoot apical meristem, which also contains a stem cell niche. Interestingly, organ outgrowth has been proposed to generate compression in the saddle-shaped organ–meristem boundary domain. Yet whether such growth-induced mechanical stress affects chromatin in plant tissues is unknown. Here, by imaging the nuclear envelope in vivo over time and quantifying nucleus deformation, we demonstrate the presence of active nuclear compression in that domain. We developed a quantitative pipeline amenable to identifying a subset of very deformed nuclei deep in the boundary and in which nuclei become gradually narrower and more elongated as the cell contracts transversely. In this domain, we find that the number of chromocenters is reduced, as shown by chromatin staining and labeling, and that the expression of linker histone H1.3 is induced. As further evidence of the role of forces on chromatin changes, artificial compression with a MicroVice could induce the ectopic expression of H1.3 in the rest of the meristem. Furthermore, while the methylation status of chromatin was correlated with nucleus deformation at the meristem boundary, such correlation was lost in the h1.3 mutant. Altogether, we reveal that organogenesis in plants generates compression that is able to have global effects on chromatin in individual cells.

Forces act as instructive mechanical signals that affect all aspects of cell and developmental biology (1, 2). Although much attention has been paid to the role of forces at the cell cortex, forces can also propagate to the nucleus and affect chromatin and gene expression (3–6). In turn, chromatin changes can also affect nucleus stiffness and shape (7). However, the impact of forces on nuclei has mainly been studied in single cell systems using artificial micromechanical manipulations, so far. Patterns of forces are naturally present in multicellular tissues. In particular, mechanical conflicts result from differential growth and tissue morphogenesis (e.g., refs. 8 and 9). In plants, because cells are encaged in a wall, cell movement is hindered; when tissues grow and change their shape, cells have to cope with the resulting mechanical stress without resolving to cell intercalation (nor cell death in young tissues). In Arabidopsis shoot apical meristems, tissue folding occurs at the boundary between organs and meristem. Finite element model simulations suggest that this domain experiences highly anisotropic tension in the circumferential direction or radial compression (10). Radial contraction of the outer cell wall has been reported in that domain in previous studies and would be consistent with compression at the boundary (11). Here, we characterized the nuclear compression at the organ boundary correlating with changes of chromatin organization and linker histone H1.3 activity.     

Donor CD8 T cell activation is critical for greater renal disease severity in female chronic graft-vs.-host mice and is associated with increased splenic ICOS host CD4 T cells and IL-21 expression

Lupus-like renal disease in DBA/2-into-F1 (DBA → F1) mice is driven by donor CD4 T cells and is more severe in females. Donor CD8 T cells have no known role. As expected, we observed that females receiving unfractionated DBA splenocytes (CD8 intact → F1) exhibited greater clinical and histological severities of renal disease at 13 weeks compared to males. Surprisingly, sex-based differences in renal disease severity were lost in CD8 depleted → F1 mice due to an improvement in females and a worsening in males. CD8 intact → F1 female mice exhibited significantly greater donor and host effector (CD44^hi, CD62L^lo) CD4 T cells and ICOS^hi CD4 T follicular helper cells than males. CD8 depleted → F1 female mice exhibited a reduction in the absolute numbers of host, but not donor CD4 Tfh cells and lost the significant increase in host CD4 effector cells vs. males. Greater female IL-21 expression, a product of Tfh cells, was seen in CD8 intact → F1 and although reduced was still greater than male CD8 depleted → F1 mice. Thus, donor CD8 T cells have a critical role in mediating sex-based differences in lupus renal disease severity possibly through greater host ICOS^hi CD4 T cell involvement.     

High-throughput sequencing of microdissected chromosomal regions

The linkage of disease gene mapping with DNA sequencing is an essential strategy for defining the genetic basis of a disease. New massively parallel sequencing procedures will greatly facilitate this process, although enrichment for the target region before sequencing remains necessary. For this step, various DNA capture approaches have been described that rely on sequence-defined probe sets. To avoid making assumptions on the sequences present in the targeted region, we accessed specific cytogenetic regions in preparation for next-generation sequencing. We directly microdissected the target region in metaphase chromosomes, amplified it by degenerate oligonucleotide-primed PCR, and obtained sufficient material of high quality for high-throughput sequencing. Sequence reads could be obtained from as few as six chromosomal fragments. The power of cytogenetic enrichment followed by next-generation sequencing is that it does not depend on earlier knowledge of sequences in the region being studied. Accordingly, this method is uniquely suited for situations in which the sequence of a reference region of the genome is not available, including population-specific or tumor rearrangements, as well as previously unsequenced genomic regions such as centromeres.     

Accumulation of Depressive Symptoms and Carotid Intima-Media Thickness: the Cardiovascular Risk in Young Finns Study

Background

The association between depressive symptoms and subclinical atherosclerosis has been inconsistent.

Purpose

We sought to replicate our previous study, which demonstrated a positive relation between depressive symptoms and subclinical atherosclerosis assessed with carotid intima-media thickness (IMT) in men, using a newer measurement of carotid IMT and a cumulative loading of depressive symptoms over three follow-ups.

Methods

The sample comprised 996 adults (352 men) aged 30 to 45 years in 2007 from a prospective population-based Finnish sample. The participants completed a modified version of Beck Depression Inventory in 1992, 1997, and 2001. Carotid IMT was assessed with ultrasound in 2001 and 2007. Cardiovascular risk factors (i.e., body mass index, systolic blood pressure, low-density lipoprotein cholesterol, and smoking) were measured in childhood (1980) and in adulthood (2007).

Results

We found no association between the accumulative depression index and carotid IMT before or after controlling for the traditional risk factors (all p values ≥0.67). Depressive symptoms did not predict IMT progression over two time points and the highest level of carotid wall thickening. Imputed and non-imputed data sets provided similar results. Results remained the same when men and women were analyzed separately. Additional analyses revealed no significant interactions between depressive symptoms and cardiovascular risk factors (i.e., body mass index and systolic blood pressure) on carotid IMT (all p values >0.15).

Conclusions

The findings of this population-based study did not indicate any direct association between depressive symptoms and carotid IMT in asymptomatic, young adults.

     

Sources of Potential Lead Exposure Among Pregnant Women in New Mexico

The objectives of this study were to ascertain the prevalence and potential sources of lead exposure among pregnant women residing in a socially-disadvantaged immigrant community in Albuquerque, New Mexico. Pregnant women (n = 140) receiving prenatal care through a community clinic participated in a structured interview and screening to measure their blood lead levels (BLLs). Potential sources of lead exposure were ascertained by the CDC and New Mexico Department of Health questionnaires. Self-reported risk factors were examined as predictors of BLLs using multiple linear regression and partial least squares discriminant analysis. Most patients were Spanish-speaking (88.6%), Latina (95%), foreign-born (87.1%), lacked health insurance (86.4%), and had a high school education or lower (84.3%). While risk factors were prevalent in this population, only three women (2.1%) had BLLs ≥3 μg/dL. Results of multivariate analyses demonstrated that pica symptoms in pregnancy, history of elevated BLLs before pregnancy, use of non-commercial pottery, and living in older houses were important predictors of elevated BLLs. Although the prevalence of other risk factors relevant to immigrant communities (i.e., use of traditional/folk remedies and cosmetics, seasonings and food products from Mexico) was high, they were not predictive of elevated BLLs. Clinics providing prenatal care to immigrant Hispanic communities should carefully assess patients’ pica symptoms, use of non-commercial pottery, and a history of elevated BLLs. Moreover, additional efforts need to focus on the development of screening questionnaires which better reflect exposures of concern in this population.     

Brief Challenges on Medicinal Plants: An Eye‐Opening Look at Ageing‐Related Disorders

Several studies have reported that nature‐derived antioxidants may prevent free radicals over‐production and therefore control the onset and prevent the exacerbation of different kinds of diseases caused by oxidative stress and redox‐derived stressors, including ageing, fundamentally by suppressing the oxidative by‐products‐mediated degradation. Naturally derived antioxidants exert their anti‐ageing action via a panoply of signalling systems, many of which engaging reactive oxygen and nitrogen species scavenging, with the Nrf2/Keap1‐ARE system and improving the many survival genes and functions (such as the pathway mTOR/Foxo/SIRT1) able to slow cellular senescence. Most of the research in this field has evaluated the regulative effects and even pathways of herbal extracts with antioxidant property in the ageing process, and various age‐related disorders such as cardiovascular disease, ischaemia‐reperfusion injury, coronary and myocardial circulatory perfusion, peripheral vascular resistance, and even neurodegenerative disorders are prevented plant phytochemicals often via their antioxidant potential. A much more complex ability to interact with survival functions makes these compounds successfully active in preventing ageing‐related disorders. This report aimed to discuss in more detail some selected medicinal plants including Allium sativum, Aloe vera, Crataegus spp., Cynara scolymus, Eleutherococcus senticosus, Ginkgo biloba, Hippophae rhamnoides, Panax ginseng, Rosmarinus officinalis, Schizandra chinensis, Vitis vinifera and seaweeds in the prevention of ageing‐related pathologies. A systematic overview of the relevant information in the antioxidant function of the many herbal products reviewed here for the control of the ageing process is proposed, to provide a new horizon on the design of anti‐ageing herbal medicines.     

From the Cover: Maternal age effect and severe germ-line bottleneck in the inheritance of human mitochondrial DNA

The manifestation of mitochondrial DNA (mtDNA) diseases depends on the frequency of heteroplasmy (the presence of several alleles in an individual), yet its transmission across generations cannot be readily predicted owing to a lack of data on the size of the mtDNA bottleneck during oogenesis. For deleterious heteroplasmies, a severe bottleneck may abruptly transform a benign (low) frequency in a mother into a disease-causing (high) frequency in her child. Here we present a high-resolution study of heteroplasmy transmission conducted on blood and buccal mtDNA of 39 healthy mother–child pairs of European ancestry (a total of 156 samples, each sequenced at ∼20,000× per site). On average, each individual carried one heteroplasmy, and one in eight individuals carried a disease-associated heteroplasmy, with minor allele frequency ≥1%. We observed frequent drastic heteroplasmy frequency shifts between generations and estimated the effective size of the germ-line mtDNA bottleneck at only ∼30–35 (interquartile range from 9 to 141). Accounting for heteroplasmies, we estimated the mtDNA germ-line mutation rate at 1.3 × 10⁻⁸ (interquartile range from 4.2 × 10⁻⁹ to 4.1 × 10⁻⁸) mutations per site per year, an order of magnitude higher than for nuclear DNA. Notably, we found a positive association between the number of heteroplasmies in a child and maternal age at fertilization, likely attributable to oocyte aging. This study also took advantage of droplet digital PCR (ddPCR) to validate heteroplasmies and confirm a de novo mutation. Our results can be used to predict the transmission of disease-causing mtDNA variants and illuminate evolutionary dynamics of the mitochondrial genome.The centerpiece of cellular metabolic machinery—the mitochondrion—harbors a 16.5-kb genome, mitochondrial DNA (mtDNA). Mutations in mtDNA cause over 200 diseases and contribute to diabetes, cancer, male infertility, Parkinson’s and Alzheimer’s diseases (1). In mammals, mtDNA mutates at high rates and is maternally inherited, making it a popular marker in evolutionary genetics (2). Despite its importance, mtDNA has drifted away from the spotlight eclipsed by nuclear DNA studies (3), and there are still gaps in our understanding of the basic aspects of human mtDNA biology. The lack of cures for diseases caused by mtDNA mutations makes it critical to understand how these mutations arise and are transmitted between generations.Heteroplasmy, the presence of more than one mtDNA variant in a cell or a tissue, is the result of a de novo mtDNA mutation occurring in an individual or inherited through the maternal lineage. Currently there is no consensus about how prevalent mtDNA heteroplasmy is in human populations (4, 5). Such knowledge is crucial for assessing the load of mtDNA pathogenic mutations, formulating prognoses for patients with mtDNA diseases, and preimplantation diagnostics after mtDNA replacement in oocytes. Most mtDNA diseases are heteroplasmic and their phenotype depends on the allele frequency of the pathogenic variant (1).Heteroplasmy levels can change dramatically between generations owing to genetic drift during the germ-line bottleneck—a reduction in the number of mtDNA segregating units during oogenesis (6–8). The size of the bottleneck for mice has been evaluated to be 185 (9), yet for humans this size is difficult to obtain experimentally. Published estimates of the human bottleneck size are too broad [1–200 (10, 11)] to be useful in predicting the transmission of disease variants. Genetic drift theory predicts that a small bottleneck size will result in drastic shifts in heteroplasmy levels from a mother to her child, potentially reaching nondisease levels or levels with higher disease severity. After fertilization, mtDNA variants are distributed among cells owing to mitotic segregation—the random partitioning of mitochondria during cell divisions (12). We also lack an accurate estimate of the germ-line mtDNA mutation rate in humans, with pedigree and phylogenetic studies producing conflicting results (13, 14).To conduct a population study of heteroplasmy transmission, we analyzed full-length mtDNA in 39 mother–child pairs using the MiSeq platform. Accounting for PCR and sequencing errors, we were able to accurately score heteroplasmies with allele frequency above 1%. With these data, we addressed (i) how common heteroplasmy is in a human population, (ii) how heteroplasmy frequency changes between tissues of the same individual and between generations, and (iii) whether maternal age at conception influences heteroplasmy occurrence in a child. We also estimated the size of the germ-line mtDNA bottleneck and the germ-line mutation rate via population genetics modeling of heteroplasmies. Focused on heteroplasmy inheritance in healthy individuals, our data serve as a valuable baseline to study disease associations for mtDNA and provide important insights into mtDNA evolution.     

Physical and Chemical Stability of Dexamethasone Sodium Phosphate in Intravenous Admixtures Used to Prevent Chemotherapy-Induced Nausea and Vomiting

Purpose: Dilute intravenous (IV) admixtures of dexamethasone sodium phosphate (DSP) are becoming increasingly used in antiemetic regimens to prevent chemotherapy-induced nausea and vomiting (CINV). Based on its chemical structure and previous studies, DSP is known to be susceptible to hydrolysis and oxidation under certain conditions. There are limited data to directly support the selection of IV diluents, storage conditions, and beyond-use dates for the dilute IV solutions of DSP used in the antiemetic regimens. This study was designed to investigate these parameters. Methods: A stability-indicating high-performance liquid chromatography (HPLC) method was first developed for the analysis of DSP. Commercially available 100 mg/10 mL DSP injection vials were used to prepare the IV admixtures of DSP in 0.9% sodium chloride injection or 5% dextrose injection. The final DSP concentrations were 0.08 or 0.4 mg/mL, which bracketed the range commonly used in antiemetic regimens. These admixtures were packaged in 50-mL polyvinylchloride (PVC) bags and stored at room temperature or under refrigeration for 14 days. Samples from each IV bag underwent visual, pH, and HPLC assessments on days 0, 1, 3, 7, and 14. Results: Immediately after preparation, the IV admixtures of DSP appeared clear, colorless, and free of particulate matters. The initial pH values were 6.4 to 6.8 and 7.0 to 7.8 for samples in 0.9% sodium chloride and 5% dextrose, respectively. The initial DSP concentrations of all samples were within 96% to 100% of the expected values. Over the 14 days of storage at room temperature or refrigeration, no significant change was observed for the visual appearance of any IV bags. The pH of all samples remained within one pH unit from the initial values. The HPLC results confirmed that all samples retained 94% to 100% of original drug concentrations and that no significant degradation products were observed. Conclusions: Intravenous admixtures of DSP at 0.08 to 0.4 mg/mL are compatible with 0.9% sodium chloride and 5% dextrose in PVC bags. These admixtures are also chemically and physically stable when stored at room temperature or under refrigeration for up to 14 days.     

Novel methodology to determine the accuracy of the OmniPod insulin pump: a key component of the artificial pancreas system

Background

This article describes two novel and easy approaches for assessing the accuracy of insulin pumps as implemented within the artificial pancreas system. The approaches are illustrated by data testing the OmniPod Insulin Management System at its lowest delivery volume (0.05 U) and at doses of 0.1, 0.2, 1, and 6U.

Method

In method 1, a pipette, digital microscope, and imaging software were used to measure average bolus delivery on a linear scale for multiple volumes. In method 2, a digital microscope and imaging software were used to measure the volume of a spherical bolus of 0.05 U of insulin.

Results

Bench testing results using the two novel methods demonstrated that the OmniPod is extremely accurate, with a relative error ranging from -0.90% to +0.96% for all measured doses (0.05, 0.1, 0.2, 1, and 6 U). In method 1, at target bolus dose of 0.05 U, the mean delivered dose (± standard deviation) was 0.0497 ± 0.003 U, 0.099 ± 0.005 U at 0.1 U, 0.2 ± <1e-5 U at 0.2 U, 1.001 ± 0.018 U at 1 U, and 6.03 ± 0.04 U at 6 U. In method 2, at target bolus dose of 0.5 ml, the mean delivered dose for both OmniPods was 0.505 ± 0.014.

Conclusions

Both methods confirmed a high degree of accuracy for the OmniPod insulin pump. These techniques can be used to estimate delivery volume in other infusion pumps as well.