Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch

High-throughput data integration of RNA-miRNA-circRNA reveals novel insights into mechanisms of benzo[a]pyrene-induced carcinogenicity

The chain of events leading from a toxic compound exposure to carcinogenicity is still barely understood. With the emergence of high-throughput sequencing, it is now possible to discover many different biological components simultaneously. Using two different RNA libraries, we sequenced the complete transcriptome of human HepG2 liver cells exposed to benzo[a]pyrene, a potent human carcinogen, across six time points. Data were integrated in order to reveal novel complex chemical–gene interactions. Notably, we hypothesized that the inhibition of MGMT, a DNA damage response enzyme, by the over-expressed miR-181a-1_3p induced by BaP, may lead to liver cancer over time

Oxidative Stress Mechanisms Do Not Discriminate between Genotoxic and Nongenotoxic Liver Carcinogens

It is widely accepted that in chemical carcinogenesis different modes-of-action exist, e.g., genotoxic (GTX) versus nongenotoxic (NGTX) carcinogenesis. In this context, it has been suggested that oxidative stress response pathways are typical for NGTX carcinogenesis. To evaluate this, we examined oxidative stress-related changes in gene expression, cell cycle distribution, and (oxidative) DNA damage in human hepatoma cells (HepG2) exposed to GTX-, NGTX-, and noncarcinogens, at multiple time points (4–8–24–48–72 h). Two GTX (azathriopine (AZA) and furan) and two NGTX (tetradecanoyl-phorbol-acetate, (TPA) and tetrachloroethylene (TCE)) carcinogens as well as two noncarcinogens (diazinon (DZN, d-mannitol (Dman)) were selected, while per class one compound was deemed to induce oxidative stress and the other not. Oxidative stressors AZA, TPA, and DZN induced a 10-fold higher number of gene expression changes over time compared to those of furan, TCE, or Dman treatment. Genes commonly expressed among AZA, TPA, and DZN were specifically involved in oxidative stress, DNA damage, and immune responses. However, differences in gene expression between GTX and NGTX carcinogens did not correlate to oxidative stress or DNA damage but could instead be assigned to compound-specific characteristics. This conclusion was underlined by results from functional readouts on ROS formation and (oxidative) DNA damage. Therefore, oxidative stress may represent the underlying cause for increased risk of liver toxicity and even carcinogenesis; however, it does not discriminate between GTX and NGTX carcinogens

Dystrophin in the Neonatal and Adult Rat Intestine

Background: Gastrointestinal (GI) complaints are frequently noted in aging dystrophinopathy patients, yet their underlying molecular mechanisms are largely unknown. As dystrophin protein isoform 71 (Dp71) is particularly implicated in the development of smooth muscle cells, we evaluated its distribution in the neonatal and adult rat intestine in this study. Methods: Dp71 expression levels were assessed in the proximal (duodenum, jejunum and ileum) and distal (caecum, colon and rectum) intestine by Western blotting and qPCR. In addition, the cellular distribution of total Dp was evaluated in the duodenum and colon by immunohistochemical colocalization studies with alpha-smooth muscle actin (aSMA), Hu RNA binding proteins C and D (HuC/HuD) for neurons and vimentin (VIM) for interstitial cells. Results: In neonatal and adult rats, the distal intestine expressed 2.5 times more Dp71 protein than the proximal part (p &lt; 0.01). This regional difference was not observed in Dp71 mRNA. During both stages, Dp-immunoreactivity was predominant in the muscularis propria, where it co-localized with aSMA and HuC/HuD. Conclusions: In neonatal and adult rats, Dp71 was expressed highest in the distal intestine. Together with the observation that Dp may be expressed by myenteric neurons, this warrants a paradigm shift in the treatment of GI comorbidities

Time-Response Evaluation by Transcriptomics of Methylmercury Effects on Neural Differentiation of Murine Embryonic Stem Cells

Current globally harmonized Organisation for Economic Co-operation and Development (OECD) animal test guidelines for developmental toxicity require high numbers of experimental animals. To reduce animal use in this field, alternative developmental toxicity assays are highly desirable. We previously developed a dynamic in vitro model for screening effects of possible neurodevelopmental toxicants, using neural cell differentiation of pluripotent murine embryonic stem cells. To further mechanistically characterize the mouse neural embryonic stem cell test (ESTn) and to improve detection of possible neurodevelopmental toxicants, gene expression patterns were studied describing neural cell differentiation over time, as well as the impact on gene expression of exposure to the well-known neurotoxicant methylmercury (MeHg). A transcriptomics study was performed to examine whole-genome expression changes during the first 7 days of the cell differentiation protocol. Specific gene clusters were identified and enrichment analysis of Gene Ontology (GO) terms and gene sets derived from literature was performed using DAVID and T-profiler. Over time, a decrease of blastocyst and trophectoderm GO terms was observed, which included well-characterized pluripotency genes. Furthermore, an increase in the range of neural development-related GO terms, such as neuron differentiation and the wnt pathway, was observed. Analysis of gene expression using principle component analysis showed a time-dependent track in untreated cells, describing the process of neural differentiation. Furthermore, MeHg was shown to induce deviation from the predefined differentiation track. The compound inhibited general development GO terms and induced neural GO terms over time. This system appears promising for studying compound effects on neural differentiation in a mechanistic approach