Longitudinal Analysis of Antibody Responses to Trachoma Antigens Before and After Mass Drug Administration.

Blinding trachoma, caused by the bacteria Chlamydia trachomatis, is a neglected tropical disease targeted for elimination by 2020. A major component of the elimination strategy is mass drug administration (MDA) with azithromycin. Currently, program decisions are made based on clinical signs of ocular infection, but we have been investigating the use of antibody responses for post-MDA surveillance. In a previous study, IgG responses were detected in children lacking clinical evidence of trachoma, suggesting that IgG responses represented historical infection. To explore the utility of serology for program evaluation, we compared IgG and IgA responses to trachoma antigens and examined changes in IgG and IgA post-drug treatment. Dried blood spots and ocular swabs were collected with parental consent from 264 1-6 year olds in a single village of Kongwa District, central Tanzania. Each child also received an ocular exam for detection of clinical signs of trachoma. MDA was given, and six months later an additional blood spot was taken from these same children. Ocular swabs were analyzed for C. trachomatis DNA and antibody responses for IgA and total IgG were measured in dried bloods spots. Baseline antibody responses showed an increase in antibody levels with age. By age 6, the percentage positive for IgG (96.0%) was much higher than for IgA (74.2%). Antibody responses to trachoma antigens declined significantly six months after drug treatment for most age groups. The percentage decrease in IgA response was much greater than for IgG. However, no instances of seroreversion were observed. Data presented here suggest that focusing on concordant antibody responses in children will provide the best serological surveillance strategy for evaluation of trachoma control programs

Quantification of HIV-1 RNA Among Men Who Have Sex With Men Using an At-Home Self-Collected Dried Blood Spot Specimen: Feasibility Study

Background: Suboptimal antiretroviral therapy (ART) adherence and disengagement in care present significant public health challenges because of the increased probability of HIV transmission. In the United States, men who have sex with men (MSM) continue to be disproportionately affected by HIV, highlighting a critical need to engage high-risk MSM living with HIV who are not engaged or retained in care. Objective: The aim of the study was to assess the feasibility of at-home blood self-collection and laboratory quantification of HIV-1 RNA viral load (VL) to report laboratory-based VL outcomes and compare self-reported and laboratory-reported VL Methods: Between 2016 and 2017, 766 US HIV-positive MSM enrolled in a Web-based behavioral intervention were invited to participate in an at-home dried blood spot (DBS) collection study using HemaSpot-HF kits (Spot On Sciences, Inc, Austin, TX) for laboratory-quantified VL. Results: Of those invited to participate, 72.3% (554/766) enrolled in the DBS study. Most (79.2%, 439/554) men enrolled reported attempting to collect their blood, 75.5% (418/554) of participants mailed a DBS specimen to the research laboratory, and 60.8% (337/554) had an adequate blood sample for VL testing. Of the 337 specimens tested for VL by the laboratory, 52.5% (177/337) had detectable VL (median: 3508 copies/mL; range: 851-1,202,265 copies/mL). Most men (83.9%, 135/161) who returned a DBS specimen with laboratory-quantified detectable VL self-reported an undetectable VL during their last clinical visit. Conclusions: Home collection of DBS samples from HIV-positive MSM is feasible and has the potential to support clinical VL monitoring. Discrepant laboratory HIV-1 RNA values and self-reported VL indicate a need to address perceived VL status, especially in the era of treatment as prevention. Most participants were willing to use an at-home DBS kit in the future, signaling an opportunity to engage high-risk MSM in long-term HIV care activities

Rapid Diagnosis of Trichomonas vaginalis by Testing Vaginal Swabs in an Isothermal Helicase-Dependent AmpliVue Assay

The AmpliVue™ Trichomonas Assay (Quidel) is a new FDA cleared rapid test for qualitative detection of Trichomonas vaginalis (TV) DNA in female vaginal specimens. The assay is based on BioHelix’s Helicase-Dependent Amplification (HDA) isothermal technology in conjunction with a disposable lateral-flow detection device, with a total turn-around time of approximately 45 minutes

Clinical and Epidemiologic Research Measuring Trachomatous Inflammation-Intense (TI) When Prevalence Is Low Provides Data on Infection With Chlamydia trachomatis

PURPOSE. Clinical trachoma is the current measure of effectiveness of antibiotic and environmental improvements in trachoma endemic communities. Impact assessments measure only trachomatous inflammation-follicular (TF). Trachomatous inflammation-intense (TI) is not used for decisions on stopping mass drug administration (MDA) or achieving intervention goals. We tested the supposition that TI was not associated with Chlamydia trachomatis when disease prevalence is low. METHODS. In 35 communities undergoing MDA as part of a larger project, 110 children ages 1 to 9 years were randomly selected in each community for surveys at baseline, 6, and 12 months. Both eyelids were graded for TF and TI, and a swab for detection of C. trachomatis infection was taken. RESULTS. Overall TF prevalence was 5% at baseline. Cases of TI alone constituted 15% of trachoma; 37% of TI cases had infection. At 6 and 12 months, the proportion of trachoma cases that had TI only was 13% and 20%; infection rates were similar to the rates in cases with TF alone. CONCLUSIONS. Despite low prevalence of trachoma, infection rates for TF alone and TI alone were similar at each time point. The exclusion of cases of TI alone when reporting trachoma prevalence discards additional information on infection. Trachomatous inflammation-intense could be considered as part of impact surveys

Field Evaluation of the Cepheid GeneXpert Chlamydia trachomatis assay for Detection of Infection in a Trachoma Endemic Community in Tanzania.

\ud \ud To determine the sensitivity, specificity, and field utility of the Cepheid GeneXpert Chlamydia trachomatis (CT) Assay (GeneXpert) for ocular chlamydia infection compared to Roche Amplicor CT assay (Amplicor). In a trachoma-endemic community in Kongwa Tanzania, 144 children ages 0 to 9 were surveyed to assess clinical trachoma and had two ocular swabs taken. One swab was processed at Johns Hopkins University, Baltimore MD, using Amplicor, (Roche Molecular Diagnostics) and the other swab was processed at a field station in Kongwa using the GeneXpert Chlamydia trachomatis/Neisseria gonorrhoeae assay (Cepheid). The sensitivity and specificity of GeneXpert was compared to the Amplicor assay. Of the 144 swabs taken the prevalence of follicular trachoma by clinical exam was 43.7%, and by evidence of infection according to Amplicor was 28.5%. A total of 17 specimens (11.8%) could not be processed by GeneXpert in the field due to lack of sample volume, other specimen issues or electricity failure. The sensitivity of GeneXpert when compared to Amplicor was 100% and the specificity was 95%. The GeneXpert test identified more positives in individuals with clinical trachoma than Amplicor, 55% versus 52%. The GeneXpert test for C. trachomatis performed with high sensitivity and specificity and demonstrated excellent promise as a field test for trachoma control.\u

An inverse relationship to germline transcription defines centromeric chromatin in C. elegans

Centromeres are chromosomal loci that direct segregation of the genome during cell division. The histone H3 variant CENP-A (also known as CenH3) defines centromeres in monocentric organisms, which confine centromere activity to a discrete chromosomal region, and holocentric organisms, which distribute centromere activity along the chromosome length1–3. Because the highly repetitive DNA found at most centromeres is neither necessary nor sufficient for centromere function, stable inheritance of CENP-A nucleosomal chromatin is postulated to epigenetically propagate centromere identity4. Here, we show that in the holocentric nematode Caenorhabditis elegans pre-existing CENP-A nucleosomes are not necessary to guide recruitment of new CENP-A nucleosomes. This is indicated by lack of CENP-A transmission by sperm during fertilization and by removal and subsequent reloading of CENP-A during oogenic meiotic prophase. Genome-wide mapping of CENP-A location in embryos and quantification of CENP-A molecules in nuclei revealed that CENP-A is incorporated at low density in domains that cumulatively encompass half the genome. Embryonic CENP-A domains are established in a pattern inverse to regions that are transcribed in the germline and early embryo, and ectopic transcription of genes in a mutant germline altered the pattern of CENP-A incorporation in embryos. Furthermore, regions transcribed in the germline but not embryos fail to incorporate CENP-A throughout embryogenesis. We propose that germline transcription defines genomic regions that exclude CENP-A incorporation in progeny, and that zygotic transcription during early embryogenesis remodels and reinforces this basal pattern. These findings link centromere identity to transcription and shed light on the evolutionary plasticity of centromeres

Adaptive designs undertaken in clinical research: a review of registered clinical trials

Adaptive designs have the potential to improve efficiency in the evaluation of new medical treatments in comparison to traditional fixed sample size designs. However, they are still not widely used in practice in clinical research. Little research has been conducted to investigate what adaptive designs are being undertaken. This review highlights the current state of registered adaptive designs and their characteristics. The review looked at phase II, II/III and III trials registered on ClinicalTrials.gov from 29 February 2000 to 1 June 2014, supplemented with trials from the National Institute for Health Research register and known adaptive trials. A range of adaptive design search terms were applied to the trials extracted from each database. Characteristics of the adaptive designs were then recorded including funder, therapeutic area and type of adaptation. The results in the paper suggest that the use of adaptive designs has increased. They seem to be most often used in phase II trials and in oncology. In phase III trials, the most popular form of adaptation is the group sequential design. The review failed to capture all trials with adaptive designs, which suggests that the reporting of adaptive designs, such as in clinical trials registers, needs much improving. We recommend that clinical trial registers should contain sections dedicated to the type and scope of the adaptation and that the term 'adaptive design' should be included in the trial title or at least in the brief summary or design sections

Epigenetic Regulation of Germline Development in C. elegans

To retain cell identity during development, cells must remember patterns of gene expression through cell division. The MES proteins in Caenorhabditis elegans are key regulators of gene expression in the germline and are necessary in parents for fertility in the next generation. MES-2, MES-3, and MES-6 form the C. elegans Polycomb Repressive Complex 2 (PRC2) and generate a repressive histone modification, methylation on Lysine 27 of Histone H3 (H3K27me), on genes repressed in the germline. MES-4 generates a different histone modification, H3K36me, on genes expressed in the germline. To further define the targets of MES protein regulation, determine if they work together to regulate gene expression, and investigate when they are important during germline development, I used genomics, genetics, and microscopy approaches. Transcript profiling of dissected mutant germlines revealed that MES-2/3/6 and MES-4 cooperate to promote expression of germline genes and repress somatic genes and genes on the X chromosome. Loss of MES-4 from germline genes causes H3K27me3 to spread to germline genes, resulting in reduced H3K27me3 elsewhere on the autosomes and especially on the X. This finding supports the model that methylation of H3K36 antagonizes methylation of H3K27 on the same histone tails. My finding that loss of MES-2, 3, or 6 results in expression from the X chromosomes and sterility, unless the X chromosome is repressed by other means, showed that the essential role of MES-2/3/6 in worms is repression of the X chromosomes in germ cells. I determined that repressive H3K27me3 is transmitted to embryos by both sperm and oocytes. By generating embryos containing some chromosomes with and some lacking H3K27me3, I showed that in embryos lacking MES-2/3/6 function, H3K27me3 is transmitted to daughter chromatids through several rounds of cell division. In embryos with MES-2/3/6 function, the mosaic pattern of H3K27me3 is perpetuated through embryogenesis. Subsequently, during germline proliferation in larval stages, H3K27me3 accumulates on all chromosomes. During germline proliferation in larvae is also when I found MES-3 to be most important for germline development in the next generation. These latter two findings suggest that germline memory is reset during germline proliferation. Taken together, my findings support a "germline memory model" in which MES-4 and H3K36me act as a memory of germline gene expression and help concentrate MES-2/3/6 repression on the X chromosome. MES-2/3/6 and H3K27me3 act as a memory of germline gene repression, most importantly on the X chromosomes. The germline memory generated by the MES proteins is epigenetically transmitted across generations and is critical for the proper development of nascent germ cells