Bacteriophages fEV-1 and fD1 Infect Yersinia pestis

Bacteriophages vB_YpeM_fEV-1 (fEV-1) and vB_YpeM_fD1 (fD1) were isolated from incoming sewage water samples in Turku, Finland, using Yersinia pestis strains EV76 and KIM D27 as enrichment hosts, respectively. Genomic analysis and transmission electron microscopy established that fEV-1 is a novel type of dwarf myovirus, while fD1 is a T4-like myovirus. The genome sizes are 38 and 167 kb, respectively. To date, the morphology and genome sequences of some dwarf myoviruses have been described; however, a proteome characterization such as the one presented here, has currently been lacking for this group of viruses. Notably, fEV-1 is the first dwarf myovirus described for Y. pestis. The host range of fEV-1 was restricted strictly to Y. pestis strains, while that of fD1 also included other members of Enterobacterales such as Escherichia coli and Yersinia pseudotuberculosis. In this study, we present the life cycles, genomes, and proteomes of two Yersinia myoviruses, fEV-1 and fD1.     

Onset of sexual maturation in female mice as measured in behavior and fertility: Interactions of exposure to males, phytoestrogen content of diet, and ano-genital distance

Age of puberty was examined in female mice through non-invasive behavioral and fertility measures, in relationship to ano-genital distance, phytoestrogen content of diet, and exposure to males post-weaning. Throughout gestation and post-natal development, females were exposed to a regular diet or one that was nutritionally similar but deficient in phytoestrogens. After segregation at weaning on the basis of a short or long ano-genital distance index (AGDI), an indirect measure of in utero androgen exposure, females were housed alone or underneath two outbred adult males for two weeks. Subsequently, an outbred male was placed in the cage of each developing female, and mating behavior, escape attempts, biting gestures, and boxing postures were recorded. Next, females were monitored for the occurrence of a copulatory plug and allowed to bear young, with pregnancy and litters monitored up to weaning. Male-exposed females fed a regular diet were immediately sexually receptive when housed directly with males, and their conceptions occurred earlier than did those of other females. Subjects fed a diet deficient in phytoestrogens were least likely to show sexual receptivity. Male-exposed females with longer AGDI displayed more escape attempts in the presence of males, regardless of diet. Once inseminated, most females carried to term and the majority of pups survived until weaning. These data suggest that phytoestrogens and AGDI interact with exposure to males in determining age at onset of puberty.     

Assessment of systemic genetic damage in pediatric inflammatory bowel disease

The etiology of distal site cancers in inflammatory bowel disease (IBD) is not well understood and requires further study. We investigated whether pediatric IBD patients' blood cells exhibit elevated levels of genomic damage by measuring the frequency of mutant phenotype (CD59-/CD55-) reticulocytes (MUT RET) as a reporter of PIG-A mutation, and the frequency of micronucleated reticulocytes (MN-RET) as an indicator of chromosomal damage. IBD patients (n = 18 new-onset disease, 46 established disease) were compared to age-matched controls (constipation or irritable bowel syndrome patients from the same clinic, n = 30) and young healthy adults age 19–24 (n = 25). IBD patients showed no indication of elevated MUT RET relative to controls (mean ± SD = 3.1 ± 2.3 × 10⁻⁶ vs. 3.6 ± 5.6 x 10⁻⁶, respectively). In contrast, 59 IBD patients where %MN-RET measurements were obtained, 10 exceeded the upper bound 90% tolerance interval derived from control subjects (i.e., 0.42%). Furthermore, each of the 10 IBD patients with elevated MN-RET had established disease (10/42), none were new-onset (0/17) (p = .049). Interestingly, each of the subjects with increased chromosomal damage was receiving anti-TNF based monotherapy at the time blood was collected (10/10, 100%), whereas this therapy was less common (20/32, 63%) among patients that exhibited ≤0.42% MN-RET (p = .040). The results clearly indicate the need for further work to understand whether the results presented herein are reproducible and if so, to elucidate the causative factor(s) responsible for elevated MN-RET frequencies in some IBD patients.     

Human blood PIG-A mutation and micronucleated reticulocyte flow cytometric assays: Method optimization and evaluation of intra- and inter-subject variation

We previously described flow cytometry-based methods for scoring the incidence of micronucleated reticulocytes (MN-RET) and PIG-A mutant phenotype reticulocytes (MUT RET) in rodent and human blood samples. The current report describes important methodological improvements for human blood analyses, including immunomagnetic enrichment of CD71-positive reticulocytes prior to MN-RET scoring, and procedures for storing frozen blood for later PIG-A analysis. Technical replicate variability in MN-RET and MUT RET frequencies based on blood specimens from 14 subjects, intra-subject variability based on serial blood draws from 6 subjects, and inter-subject variation based on up to 344 subjects age 0 to 73 years were quantified. Inter-subject variation explained most of the variability observed for both endpoints (≥77%), with much lower intra-subject and technical replicate variability. The relatively large degree of inter-subject variation is apparent from mean and standard deviation values for MN-RET (0.15 ± 0.10%) and MUT RET (4.7 ± 5.0 per million, after omission of two extreme outliers). The influences of age and sex on inter-subject variation were investigated, and neither factor affected MN-RET whereas both influenced MUT RET frequency. The lowest MUT RET values were observed for subjects <11 years old, and males had moderately higher frequencies than females. These results indicate that MN-RET and MUT RET are automation-compatible biomarkers of genotoxicity that bridge species of toxicological interest to include human populations. These data will be useful for appropriately designing future human studies that include these biomarkers of genotoxicity, and highlight the need for additional work aimed at identifying the sources of inter-individual variability reported herein.     

Interaction between Albuminuria and Treatment Group Outcomes for Patients with Renal Artery Stenosis: The NITER Study

Purpose

To perform a post-hoc analysis of the Nephropathy Ischemic Therapy (NITER) trial, which enrolled patients with atherosclerotic renal artery stenosis, to evaluate whether medical therapy plus stent placement is superior to medical therapy alone in patients without elevated albuminuria.