Gastric conditions such as gastritis, peptic ulcers, and stomach cancer may involve accompanying infections by Mycobacterium abscessus, according to researchers from India reporting in PLOS Neglected Tropical Diseases. Using 16S ribosomal RNA gene sequencing — in combination with immunohistochemistry, immunofluorescence, microbial culturing, and other targeted gene sequencing and PCR-based analyses — the team found M. abscessus in 96 of 129 individuals with gastric symptoms tested at a site in southern India. In contrast, just 42 of the individuals had detectable Helicobacter pylori, a bug previously implicated in gastric disease. From these and other findings, the authors suggest that M. abscessus "is among the most frequently observed gastric bacteria in individuals with various stomach diseases." Consequently, they say, "it is important to evaluate the significance of this infection."
Investigators from the University of Cincinnati College of Medicine, the University of California, Los Angeles, and elsewhere search for placental gene expression shifts related to preterm birth for a paper appearing in PLOS One. The team did transcriptome sequencing on placental villous samples collected from a dozen idiopathic spontaneous preterm birth cases, nine cases of acute histologic chorioamnionitis, and 11 healthy at-term births, uncovering a gene expression signature involving higher-than-usual levels of the insulin-like growth factor signaling-related genes IGFBP1, IGFBP2, and IGFBP6 that seemed to coincide with idiopathic spontaneous preterm birth. "[W]ithin the [idiopathic spontaneous preterm birth] expression signature, we detected [a] secondary signature of inflammatory markers … associated with placental maturity," they add, noting that "the expression signature of the gestational age-matched infected samples included upregulation of proliferative genes along with cell cycling and mitosis pathways."
In PLOS Genetics, a University of Montana-led team looks at high-altitude adaptations in American deer mice (Peromyscus maniculatus). Using exome sequencing-based population genetic analyses and physiological experiments, the researchers searched for transcription factor-coding variants with ties to the low oxygen conditions present at high altitudes. Based on data for 100 mice selected from environments with a range of elevations, they focused in EPAS1 SNPs that tracked with altitude in deer mice from additional sampling sites. The authors' subsequent experiments suggest the variants may impact heart rate and transcription factor activity in low oxygen conditions. "Our results suggest a mechanism by which EPAS2 may aid long-term survival of high-altitude deer mice," they write, "and provide general insights into the role that highly pleiotropic transcription factors may play in the process of environmental adaptation."