Vancomycin-induced gut microbial dysbiosis alters enteric neuron-macrophage interactions during a critical period of postnatal development

Vancomycin is a broad-spectrum antibiotic widely used in cases of suspected sepsis in premature neonates. While appropriate and potentially lifesaving in this setting, early-life antibiotic exposure alters the developing microbiome and is associated with an increased risk of deadly complications, including late-onset sepsis (LOS) and necrotizing enterocolitis (NEC). Recent studies show that neonatal vancomycin treatment disrupts postnatal enteric nervous system (ENS) development in mouse pups, which is in part dependent upon neuroimmune interactions. This suggests that early-life antibiotic exposure could disrupt these interactions in the neonatal gut. Notably, a subset of tissue-resident intestinal macrophages, muscularis macrophages, has been identified as important contributors to the development of postnatal ENS. We hypothesized that vancomycin-induced neonatal dysbiosis impacts postnatal ENS development through its effects on macrophages. Using a mouse model, we found that exposure to vancomycin in the first 10 days of life, but not in adult mice, resulted in an expansion of pro-inflammatory colonic macrophages by increasing the recruitment of bone-marrow-derived macrophages. Single-cell RNA sequencing of neonatal colonic macrophages revealed that early-life vancomycin exposure was associated with an increase in immature and inflammatory macrophages, consistent with an influx of circulating monocytes differentiating into macrophages. Lineage tracing confirmed that vancomycin significantly increased the non-yolk-sac-derived macrophage population. Consistent with these results, early-life vancomycin exposure did not expand the colonic macrophage population nor decrease enteric neuron density in CCR2-deficient mice. Collectively, these findings demonstrate that early-life vancomycin exposure alters macrophage number and phenotypes in distinct ways compared with vancomycin exposure in adult mice and results in altered ENS development.

Vinorelbine rescue therapy for dogs with primary urinary bladder carcinoma

The goal of this study was to evaluate the anti-tumour activity and toxicoses of vinorelbine as a palliative rescue therapy for dogs with primary urinary bladder carcinoma. Thirteen dogs refractory to prior chemotherapeutics and one dog naïve to chemotherapeutic treatment were enrolled. Vinorelbine (15 mg m(-2) IV) was administered intravenously along with concurrent oral anti-inflammatory drugs, if tolerated. A median of six doses of vinorelbine (range: 1-16) was administered. Two dogs (14%) had partial responses, and eight (57%) experienced stable disease. Subjective improvement in clinical signs was noted in 11 dogs (78%). Adverse events were mild and primarily haematological in nature. Median time to progression was 93 days (range: 20-239 days). Median survival time for all dogs was 187 days; median survival for 13 pre-treated dogs was 207 days. Vinorelbine may have utility in the management of canine primary urinary bladder carcinoma and should be evaluated in a prospective study.

Results of a surveillance program for persons living around the Nevada Test Site--1971 to 1980

A continuing program has been conducted since 1970 to determine levels of radioactive nuclides in adults and children from families residing in communities and ranches surrounding the Nevada Test Site. Twice each year these persons receive a whole-body count and physical examination; a urine sample from each is also submitted for radionuclide analyses. The only fission-product radionuclide routinely found in whole-body counting has been 137Cs at concentrations similar to those in persons living in other areas of the United States. The physical examinations reveal a generally healthy population, and urine samples have shown no remarkable radionuclide content.