Intramammary infections and teat canal colonization with coagulase-negative staphylococci after postmilking teat disinfection: species-specific responses.

Coagulase-negative staphylococci (CNS) are the most common pathogens associated with intramammary infections (IMI) in dairy cows. We hypothesized that postmilking teat disinfection would reduce microbial colonization of the teat canal and thus reduce the prevalence of IMI caused by certain CNS species. The efficacy of iodine postmilking teat dip was tested against CNS colonization of the teat canal, and incidence of IMI was measured. Using an udder-half model, 43 Holstein cows at the Washington State University Dairy were enrolled in the trial; postmilking teat dip was applied to one udder-half, treatment (TX), and the remaining half was an undipped control (CX). Teat canal swabbing and mammary quarter milk samples were taken in duplicate once a week for 16 wk for microbial culture. Isolates from agar cultures were presumptively identified as CNS and then speciated using PCR-RFLP and agarose gel electrophoresis. Colonization of the teat canal and IMI by CNS were assessed. Thirty CNS IMI were diagnosed and the number of new IMI in CX quarters (21) was significantly greater than that in TX mammary quarters (9). The majority of CNS IMI were caused by Staphylococcus chromogenes (30%) and Staphylococcus xylosus (40%), and the latter were appreciably reduced by teat dip. Except for S. xylosus, an association was observed between teat canal colonization and IMI by all CNS species in this study, in which the majority of IMI were preceded by teat canal colonization. The total number of CNS IMI was greater for CX group cows compared with TX group cows. However, the effect of disinfection on IMI did not appear to be the same for all CNS species.

Isolation and genetic characterization of Toxoplasma gondii from raccoons (Procyon lotor), cats (Felis domesticus), striped skunk (Mephitis mephitis), black bear (Ursus americanus), and cougar (Puma concolor) from Canada.

Viable Toxoplasma gondii was isolated by bioassay in mice from tissues of 2 feral cats (Felis domesticus), 2 raccoons (Procyon lotor), a skunk (Mephitis mephitis) trapped in remote locations in Manitoba, Canada, and a black bear (Ursus americanus) from Kuujjuaq, northern Quebec, Canada. Genotyping of these T. gondii isolates using polymorphisms at 10 nuclear markers including SAGI, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker Apico revealed 4 genotypes. None of the isolates was clonal archetypal Types I, II, and III found in the United States. These results are in contrast with the Type II genotype that is widespread in domestic animals and humans throughout the United States and Europe. This is the first genotyping of T. gondii isolates from this part of North America.

Seroprevalence of Toxoplasma gondii in mesocarnivores of the Canadian prairies.

The protozoon Toxoplasma gondii has a worldwide distribution and affects many species of warm-blooded animals. In the Canadian prairies, mesocarnivores such as striped skunks (Mephitis mephitis) and raccoons (Procyon lotor) have experienced an increase in density and distribution, and they are in close contact with human dwellings. However, there has been no systematic study on the seroprevalence of T. gondii in these mesocarnivore populations. The objectives of the current project were to determine the serum antibody prevalence of T. gondii in Canadian prairie mesocarnivores and to study the relationship between antibody prevalence and species, sex, age, location, and year of collection. Antibodies to T. gondii were found in 5 of 24 (20.8%) skunks from Saskatchewan trapped in 1999 and 5 of 40 (12.5%) in 2000. Seroprevalences for T. gondii in raccoons and skunks trapped in Manitoba were 2 of 10 (20%) raccoons trapped in 2002, 7 of 44 (15.9%) trapped in 2003, and 16 of 37 (43.2%) trapped in 2004; and in 13 of 99 (13.1%) skunks trapped in 2003, 29 of 131 (22.1%) trapped in 2004, 53 of 165 (32.1%) trapped in 2005, and 30 of 51 (58.8%) trapped in 2006. Age, location, and year, but not the host species, were important variables in the determining the seroprevalence of T. gondii in skunks and raccoons. Results confirm that T. gondii is endemic in the skunk and raccoon populations in the Canadian prairies.

Diagnosis, health beliefs, and risk of HIV infection in psychiatric patients.

OBJECTIVE: The study examined behavioral and cognitive factors that may place mentally ill persons at increased risk of infection by the human immunodeficiency virus (HIV). METHODS: Sixty-one patients consecutively admitted to a psychiatric inpatient unit of a public general hospital completed questionnaires focused on their knowledge about AIDS and their sexual practices. They also participated in a structured interview to assess how their beliefs about health related to changes in health behaviors. Responses of the psychiatric patients, of whom 54.5 percent were men and 61.5 percent were black, were categorized by diagnosis (schizophrenia, bipolar affective disorder, and depression) and were compared with responses of a control group of 32 patients with no identified psychiatric disorder who had been treated in the hospital's medical emergency room. RESULTS: Trends in the data suggested that the psychiatric patients were more likely than the control subjects to engage in high-risk sexual behaviors. Psychiatric patients with different diagnoses appeared to engage in different kinds of high-risk behaviors. Whereas control subjects seemed inclined to change their behaviors as their knowledge about HIV increased, schizophrenic patients appeared willing to change their behavior only if they believed their behavior could really make a difference in whether they would become infected. CONCLUSIONS: The relationship between specific psychiatric symptoms, knowledge about HIV, and factors influencing behavior need to be more thoroughly examined so that clinicians can develop interventions to reduce the risk of HIV infection in mentally ill persons.

Establishing generic remediation goals for the polycyclic aromatic hydrocarbons: critical issues.

Polycyclic aromatic hydrocarbons (PAHs) were one of the first classes of compounds identified as carcinogens and are often chemicals of concern at hazardous waste sites. Remediation goals established by regulatory agencies for carcinogenic PAHs in soil are generally either risk based or based on the method detection limits. PAHs are products of incomplete combustion, are components of petroleum, and as such, are prevalent in the environment from both natural and anthropogenic sources. Background concentrations are often above risk- or detection limit-based criteria, and therefore these remediation goals are of limited practical use as target criteria. In addition, the approaches used to establish target criteria do not account for several factors that may produce over- or underestimates of risk associated with the PAHs. Because of the frequency with which these compounds are detected, it is imperative that reasonably achievable and practical remediation goals be established. This paper examines the various factors that contribute to over- and underestimates of risks associated with PAHs and presents an approach for establishing cleanup criteria that takes into account health risks, background concentrations, and achievability.

Tegumental glucose permeability in male and female Schistosoma mansoni.

Tegumental hexose transporters have been kinetically characterized in mated and separated male and female Schistosoma mansoni 8-12 wk postinfection. Significant gender-specific differences in Km and Vmax were observed. In mated males, the estimated constants (mean +/- SE) were: Km = 0.63 +/- 0.31 mM, Vmax = 0.93 +/- 0.44 nmol/mg worm water/min, and the Kd = 0.25 +/- 0.09 microliter/mg worm water/min. In mated females the kinetics were: Km = 0.99 +/- 0.40 mM, Vmax = 1.22 +/- 0.42 nmol/mg worm water/min, and Kd = 0.60 +/- 0.14 microliter/mg worm water/min. The influx of 2-deoxy-D-glucose and 3-O-methylglucose has been similarly characterized; these analogs share the same glucose transporter in male and female schistosomes. 2-Deoxy-D-glucose has a higher affinity, and 3-O-methylglucose a lower affinity, than does glucose. Because mated male schistosomes supply glucose to female partners, similarities between the free glucose concentration of the male and the affinity of the transporter determined for mated female schistosomes suggest that male-to-female transfer may be a potentially rate-limiting step in glucose utilization by the female. Permeability x surface are (PS) products and Vmax/Km ratios were significantly elevated in mated schistosomes, suggesting that the transporter is primarily localized to the dorsal surface of the male. Gender- and mating-specific analyses of PS products indicate that tegumental permeability to glucose is significantly increased in mated schistosomes, and compares very favorably to that of the host liver.

Vascular tufts in retrolental fibroplasia.

Three cases of retrolental fibroplasia with vascular tufts at different locations are described. They probably represent mesenchymal proliferation in response to severe hypoxia. The tufts are reddish-pink in color and angiographically do not leak fluorescein. When present posterior to the equator they suggest an immature retinal circulation and the visual prognosis is poor.

Assessing the pain experience in children.

A paucity of literature exists on the experience of children in pain: however, its study is most relevant to the pediatric nurse who must care for the child. It is necessary for the nurse to understand the influential factors that affect the perceptions and expressions of children who have pain before she can intervene in a comfort-producing and health-promoting manner.

Clarification of foveomacular nomenclature and grid for quantitation of macular disorders.

Standardization of terminology and precise localization of lesions are imperative in the study of the natural course of various retinal vascular and macular disorders. The RAZ localizing system provides an easy and accurate way of documenting and following lesions of the posterior pole in terms of RAZ diameters rather than disc diameters. This type of quantitation is important because consideration regarding prognosis and management is often in terms of involvement of the retinal avascular zone. This type of grid system also permits the clinician to measure and follow the size of some choroidal masses. Based on our preliminary studies, it appears that at this stage of development, this method of studying and recording posterior pole lesions is of useful accuracy. Hopefully, certain guidelines, such as how close one may approach the retinal avascular zone with photocoagulation and still maintain reasonably good vision, can be more accurately determined.