Solid-Phase Microextraction and the Human Fecal VOC Metabolome

The diagnostic potential and health implications of volatile organic compounds (VOCs) present in human feces has begun to receive considerable attention. Headspace solid-phase microextraction (SPME) has greatly facilitated the isolation and analysis of VOCs from human feces. Pioneering human fecal VOC metabolomic investigations have utilized a single SPME fiber type for analyte extraction and analysis. However, we hypothesized that the multifarious nature of metabolites present in human feces dictates the use of several diverse SPME fiber coatings for more comprehensive metabolomic coverage. We report here an evaluation of eight different commercially available SPME fibers, in combination with both GC-MS and GC-FID, and identify the 50/30 µm CAR-DVB-PDMS, 85 µm CAR-PDMS, 65 µm DVB-PDMS, 7 µm PDMS, and 60 µm PEG SPME fibers as a minimal set of fibers appropriate for human fecal VOC metabolomics, collectively isolating approximately 90% of the total metabolites obtained when using all eight fibers. We also evaluate the effect of extraction duration on metabolite isolation and illustrate that ex vivo enteric microbial fermentation has no effect on metabolite composition during prolonged extractions if the SPME is performed as described herein

Delivering integrated care after sexual violence in the Democratic Republic of the Congo.

In the eastern Democratic Republic of the Congo, ongoing armed conflict increases the incidence of gender-based violence (GBV) and presents a distinct and major barrier to care delivery for all survivors of GBV. A specific challenge is providing emergency contraception, HIV prophylaxis and treatment for sexually transmitted infections to all survivors within 72 hours of violence. To address the multiple barriers to providing this time-sensitive medical care, Global Strategies and Panzi Hospital implemented the Prevention Pack Program. The Prevention Pack is a pre-packaged post-rape medical kit containing antiretroviral post-exposure prophylaxis, antibiotics for treatment of sexually transmitted infections and emergency contraception. The Prevention Pack Program combines community sensitisation about post-rape medical care with the provision of Prevention Packs and the implementation of a cloud-based and Global Positioning System (GPS)-enabled inventory management system. The Panzi Hospital gender-based violence team implemented the Prevention Pack Program at Panzi Hospital and 12 rural clinics in the South Kivu Province. The data manager took GPS coordinates of each site, provided an initial stock of Prevention Packs and then called all sites daily to determine demand for post-rape care and Prevention Pack consumption. Inventory data were entered into the GPS-enabled cloud-based inventory management system. Project personnel used the consumption rate, trends and geolocation of sites to guide Prevention Pack restocking strategy. Between 2013 and 2017, a total of 8206 individuals presented for care following rape at the study sites. Of the 1414 individuals who presented in the rural areas, 1211 (85.6%) did so within the first 72 hours of reported rape. Care was delivered continuously and without a single stockout of medication across all sites. The Prevention Pack Program provided timely and consistent access to emergency contraception, HIV prophylaxis and treatment for sexually transmitted infections for rape survivors in the eastern Democratic Republic of the Congo

Maternal HIV-1 viral load and vertical transmission of infection: The Ariel Project for the prevention of HIV transmission from mother to infant

Most HIV-1 infections of children result from mother-to-infant transmission, which may occur perinatally or postnatally, as a consequence of breast feeding1−8. In this study, the influence of maternal viral load on transmission of infection to infants from non-breast-feeding mothers was examined using samples of plasma and peripheral blood mononuclear cells (PBMCs) collected at several time points during pregnancy and the 6-month period after delivery. These samples were analyzed by several quantitative methods, including virus cultures of PBMCs and polymerase chain reaction (PCR) assays for HIV-1 RNA in plasma and DMA in PBMCs. The risk of transmission increased slightly with a higher viral load, but transmission and nontransmission occurred over the entire range of values for each assay. No threshold value of virus load was identified which discriminated between transmitters and nontransmitters. We also noted a significant rise in viral load and a decline in CD4+ lymphocytes in the six months after delivery. These findings suggest that a high maternal viral load is insufficient to fully explain vertical transmission of HIV-1. Additional studies are needed to examine the post-partum increase in viremia

Frequent Detection of Escape from Cytotoxic T-Lymphocyte Recognition in Perinatal Human Immunodeficiency Virus (HIV) Type 1 Transmission: the Ariel Project for the Prevention of Transmission of HIV from Mother to Infant

Host immunologic factors, including human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL), are thought to contribute to the control of HIV type 1 (HIV-1) replication and thus delay disease progression in infected individuals. Host immunologic factors are also likely to influence perinatal transmission of HIV-1 from infected mother to infant. In this study, the potential role of CTL in modulating HIV-1 transmission from mother to infant was examined in 11 HIV-1-infected mothers, 3 of whom transmitted virus to their offspring. Frequencies of HIV-1-specific human leukocyte antigen class I-restricted CTL responses and viral epitope amino acid sequence variation were determined in the mothers and their infected infants. Maternal HIV-1-specific CTL clones were derived from each of the HIV-1-infected pregnant women. Amino acid substitutions within the targeted CTL epitopes were more frequently identified in transmitting mothers than in nontransmitting mothers, and immune escape from CTL recognition was detected in all three transmitting mothers but in only one of eight nontransmitting mothers. The majority of viral sequences obtained from the HIV-1-infected infant blood samples were susceptible to maternal CTL. These findings demonstrate that epitope amino acid sequence variation and escape from CTL recognition occur more frequently in mothers that transmit HIV-1 to their infants than in those who do not. However, the transmitted virus can be a CTL susceptible form, suggesting inadequate in vivo immune control