Demographic factors associated with prevalence of antibody to Sin Nombre virus in deer mice in the western United States

We used long-term data collected for up to 10 yr (1994-2004) at 23 trapping arrays (i.e., webs and grids) in Arizona, Colorado, Montana, and New Mexico to examine demographic factors known or suspected to be associated with risk of infection with Sin Nombre virus (SNV) in its natural host, the deer mouse (Peromyscus maniculatus). Gender, age (mass), wounds or scars, season, and local relative population densities were statistically associated with the period prevalence of antibody (used as a marker of infection) to SNV in host populations. Nevertheless, antibody prevalence and some of the risk factors associated with antibody prevalence, such as relative population density, gender bias, and prevalence of wounding, varied significantly among sites and even between nearby trapping arrays at a single site. This suggests that local microsite-specific differences play an important role in determining relative risk of infection by SNV in rodents and, consequently, in humans. Deer mouse relative population density varied among sites and was positively and statistically associated with infection prevalence, an association that researchers conducting shorter-term studies failed to demonstrate. Both wounding and antibody prevalence increased with mass class in both males and females; this increase was much more pronounced in males than in females and wounding was more frequent in adult males than in adult females. Prevalence of wounding was greatest among seropositive deer mice, regardless of mass class, but many deer mice without detectable wounds or scars eventually became infected. Many of these patterns, which will be useful in the development of predictive models of disease risk to humans, were only detected through the application of data collected over a long (10-yr) period and with abundant replication.     

Long-term hypoxia modulates expression of key genes regulating adrenomedullary function in the late gestation ovine fetus

We previously communicated that long-term hypoxia (LTH) resulted in a selective reduction in plasma epinephrine following acute stress in fetal sheep. The present study tested the hypothesis that LTH selectively reduces adrenomedullary expression of phenylethanolamine-N-methyltransferase (PNMT), the rate-limiting enzyme for epinephrine synthesis. We also examined the effect of LTH on adrenomedullary nicotinic, muscarinic, and glucocorticoid receptor (GR) expression. Ewes were maintained at high altitude (3,820 m) from 30 to 138 days gestation (dGA); adrenomedullary tissue was collected from LTH and age-matched, normoxic control fetuses at 139-141 dGA. Contrary to our hypothesis, in addition to PNMT, adrenomedullary expression (mRNA, protein) of tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) were reduced in the LTH fetus. Immunocytochemistry indicated that TH and DBH expression was lower throughout the medulla, while PNMT appeared to reflect a reduction in PNMT-expressing cells. Nicotinic receptor alpha 1, 2, 3, 5, 6, 7, beta 1, 2, and 4 subunits were expressed in the medulla of LTH and control fetuses. Messenger RNA for alpha 1 and 7 and beta 1 and 2 subunits was lower in LTH fetuses. Muscarinic receptors M1, M2, and M3 as well as the GR were also expressed, and no differences were noted between groups. In summary, LTH in fetal sheep has a profound effect on expression of key enzymes mediating adrenomedullary catecholamine synthesis. Further, LTH impacts nicotinic receptor subunit expression potentially altering cholinergic neurotransmission within the medulla. These findings have important implications regarding fetal cardiovascular and metabolic responses to stress in the LTH fetus.     

Multilocus sequence typing supports the hypothesis that cow- and human-associated Salmonella isolates represent distinct and overlapping populations

A collection of 179 human and 156 bovine clinical Salmonella isolates obtained from across New York state over the course of 1 year was characterized using serotyping and a multilocus sequence typing (MLST) scheme based on the sequencing of three genes (fimA, manB, and mdh). The 335 isolates were differentiated into 52 serotypes and 72 sequence types (STs). Analyses of bovine isolates collected on different farms over time indicated that specific subtypes can persist over time on a given farm; in particular, a number of farms showed evidence for the persistence of a specific Salmonella enterica serotype Newport sequence type. Serotypes and STs were not randomly distributed among human and bovine isolates, and selected serotypes and STs were associated exclusively with either human or bovine sources. A number of common STs were geographically widespread. For example, ST6, which includes isolates representing serotype Typhimurium as well as the emerging serotype 4,5,12:i:-, was found among human and bovine isolates in a number of counties in New York state. Phylogenetic analyses supported the possibility that serotype 4,5,12:i:- is closely related to Salmonella serotype Typhimurium. Salmonella serotype Newport was found to represent two distinct evolutionary lineages that differ in their frequencies among human and bovine isolates. A number of Salmonella isolates carried two copies of manB (33 isolates) or showed small deletion events in fimA (nine isolates); these duplication and deletion events may provide mechanisms for the rapid diversification of Salmonella surface molecules. We conclude that the combined use of an economical three-gene MLST scheme and serotyping can provide considerable new insights into the evolution and transmission of Salmonella.     

Multilocus Sequence Typing Supports the Hypothesis that Cow- and Human-Associated Salmonella Isolates Represent Distinct and Overlapping Populations

A collection of 179 human and 156 bovine clinical Salmonella isolates obtained from across New York state over the course of 1 year was characterized using serotyping and a multilocus sequence typing (MLST) scheme based on the sequencing of three genes (fimA, manB, and mdh). The 335 isolates were differentiated into 52 serotypes and 72 sequence types (STs). Analyses of bovine isolates collected on different farms over time indicated that specific subtypes can persist over time on a given farm; in particular, a number of farms showed evidence for the persistence of a specific Salmonella enterica serotype Newport sequence type. Serotypes and STs were not randomly distributed among human and bovine isolates, and selected serotypes and STs were associated exclusively with either human or bovine sources. A number of common STs were geographically widespread. For example, ST6, which includes isolates representing serotype Typhimurium as well as the emerging serotype 4,5,12:i:-, was found among human and bovine isolates in a number of counties in New York state. Phylogenetic analyses supported the possibility that serotype 4,5,12:i:- is closely related to Salmonella serotype Typhimurium. Salmonella serotype Newport was found to represent two distinct evolutionary lineages that differ in their frequencies among human and bovine isolates. A number of Salmonella isolates carried two copies of manB (33 isolates) or showed small deletion events in fimA (nine isolates); these duplication and deletion events may provide mechanisms for the rapid diversification of Salmonella surface molecules. We conclude that the combined use of an economical three-gene MLST scheme and serotyping can provide considerable new insights into the evolution and transmission of Salmonella.     

Phenotypic covariance structure and its divergence for acoustic mate attraction signals among four cricket species

The phenotypic variance-covariance matrix (P) describes the multivariate distribution of a population in phenotypic space, providing direct insight into the appropriateness of measured traits within the context of multicollinearity (i.e., do they describe any significant variance that is independent of other traits), and whether trait covariances restrict the combinations of phenotypes available to selection. Given the importance of P, it is therefore surprising that phenotypic covariances are seldom jointly analyzed and that the dimensionality of P has rarely been investigated in a rigorous statistical framework. Here, we used a repeated measures approach to quantify P separately for populations of four cricket species using seven acoustic signaling traits thought to enhance mate attraction. P was of full or almost full dimensionality in all four species, indicating that all traits conveyed some information that was independent of the other traits, and that phenotypic trait covariances do not constrain the combinations of signaling traits available to selection. P also differed significantly among species, although the dominant axis of phenotypic variation (p(max)) was largely shared among three of the species (Acheta domesticus, Gryllus assimilis, G. texensis), but different in the fourth (G. veletis). In G. veletis and A. domesticus, but not G. assimilis and G. texensis, p(max) was correlated with body size, while p(max) was not correlated with residual mass (a condition measure) in any of the species. This study reveals the importance of jointly analyzing phenotypic traits.     

Practices of the Pregnant Self: Compliance With and Resistance To Prenatal Norms

A major challenge of medical anthropology is to assess howbiomedicine, as a vaguely-defined set of diverse texts,technologies, and practitioners, shapes the experience of selfand body. Through narrative analyses of in-depth, semi-structuredinterviews with 158 pregnant women in southern California, thispaper explores how the culture of biomedicine, encounteredformally at prenatal care check-ups and informally throughdiverse media, influences pregnant women's perceptions ofappropriate prenatal behavior. In the spirit of recent socialscientific work that draws on and challenges Foucauldian insightsto explore social relations in medicine, we posit a spectrum ofcompliance and resistance to biomedical norms upon whichindividual prenatal practices are assessed. We suggest thatpregnancy is, above all, characterized by a split subjectivity inwhich women straddle the authoritative and the subjugated, theobjective and the subjective, and the haptic as well as theoptic, in telling and often strategic ways. In so doing, weidentify the intersection between the disciplinary practices ofbiomedicine and the practices of pregnant women as a means offurnishing more fruitful insights into the oft-used term ``power'and its roles in constituting social relations in medicine.     

Zinc Secretion in the Oviduct of the Coturnix Quail

The oviduct from laying quail were used to investigate mechanisms of trace mineral secretion and the possible role of metallothionein in this process. Secretion of zinc occurred maximally at pH 5.4, which is close to the normal pH of the oviduct. Secretion occurred to a much greater extent in the isthmus and shell gland than in the magnum, the major protein-secretory section of the oviduct. Intraperitoneal administration of cadmium resulted in a marked reduction in Zn secretion from the oviduct of laying quail. This effect could not be correlated with metallothionein since metallothionein could not be detected in any section of the oviduct in control or Cd-induced quail. Small-molecular-weight metal-binding ligands were present in the isthmus and shell gland, which may play a role in trace mineral mobilization. Histological evaluation by light and elelctron microscopy show that Zn is transported from the smooth muscle cells through the connective tissue matrix in the extracellular space to the epithelial goblet cells. Presumably, Zn and other trace minerals are secreted from the secretory goblet cells into the egg.     

Unusually High Occurrence of Drug Reactions with Nafcillin

Five patients seen during a two-month period who developed untoward systemic reactions following high dose intravenous administration of nafcillin are described. Recovery was complete upon discontinuation of the drug. The clustering of these cases and the high incidence (5 of 5) of side effects are highly unusual, and suggest that the frequency of nafcillin reactions might be higher than previously suspected.