Cold acclimation induces life stage-specific responses in the cardiac proteome of western painted turtles (Chrysemys picta bellii): implications for anoxia tolerance.

Western painted turtles (Chrysemys picta bellii) are the most anoxia-tolerant tetrapod. Survival time improves at low temperature and during ontogeny, such that adults acclimated to 3°C survive far longer without oxygen than either warm-acclimated adults or cold-acclimated hatchlings. As protein synthesis is rapidly suppressed to save energy at the onset of anoxia exposure, this study tested the hypothesis that cold acclimation would evoke preparatory changes in protein expression to support enhanced anoxia survival in adult but not hatchling turtles. To test this, adult and hatchling turtles were acclimated to either 20°C (warm) or 3°C (cold) for 5 weeks, and then the heart ventricles were collected for quantitative proteomic analysis. The relative abundance of 1316 identified proteins was compared between temperatures and developmental stages. The effect of cold acclimation on the cardiac proteome was only evident in the context of an interaction with life stage, suggesting that ontogenic differences in anoxia tolerance may be predicated on successful maturation of the heart. The main differences between the hatchling and adult cardiac proteomes reflect an increase in metabolic scope with age that included more myoglobin and increased investment in both aerobic and anaerobic energy pathways. Mitochondrial structure and function were key targets of the life stage- and temperature-induced changes to the cardiac proteome, including reduced Complex II proteins in cold-acclimated adults that may help down-regulate the electron transport system and avoid succinate accumulation during anoxia. Therefore, targeted cold-induced changes to the cardiac proteome may be a contributing mechanism for stage-specific anoxia tolerance in turtles.

Racial/ethnic discrepancies in the metabolic syndrome begin in childhood and persist after adjustment for environmental factors.

BACKGROUND AND AIMS: Evaluation of metabolic syndrome (MetS) characteristics across an age spectrum from childhood to adulthood has been limited by a lack of consistent MetS criteria for children and adults and by a lack of adjustment for environmental factors. We used the pediatric and adult International Diabetes Federation (IDF) criteria to determine whether gender-specific and race-specific differences in MetS and its components are present in adolescents as in adults after adjustment for socio-economic status (SES) and lifestyle factors. METHODS AND RESULTS: Waist circumference, blood pressure, triglycerides, HDL cholesterol, and fasting glucose measures were obtained from 3100 adolescent (12-19 years) and 3419 adult (20-69 years) non-Hispanic white, non-Hispanic black, and Mexican-American participants of the 1999-2006 National Health and Nutrition Examination Surveys. We compared odds of having MetS and its components across racial/ethnic groups by age group, while adjusting for income, education, physical activity and diet quality. After adjusting for possible confounding influences of SES and lifestyle, non-Hispanic-black adolescent males exhibited a lower odds of MetS and multiple components (abdominal obesity, hypertriglyceridemia, low HDL, hyperglycemia) compared to non-Hispanic-white and Mexican-American adolescents. Compared to non-Hispanic-white adolescent males, Mexican-American adolescent males had less hypertension. There were no differences in MetS prevalence among adolescent females, though non-Hispanic-black girls exhibited less hypertriglyceridemia. CONCLUSION: Racial/ethnicity-specific differences in MetS and its components are present in both adolescence and adulthood, even after adjusting for environmental factors. These data help strengthen arguments for developing racial/ethnic-specific MetS criteria to better identify individuals at risk for future cardiovascular disease.

Universal behavior of the osmotically compressed cell and its analogy to the colloidal glass transition.

Mechanical robustness of the cell under different modes of stress and deformation is essential to its survival and function. Under tension, mechanical rigidity is provided by the cytoskeletal network; with increasing stress, this network stiffens, providing increased resistance to deformation. However, a cell must also resist compression, which will inevitably occur whenever cell volume is decreased during such biologically important processes as anhydrobiosis and apoptosis. Under compression, individual filaments can buckle, thereby reducing the stiffness and weakening the cytoskeletal network. However, the intracellular space is crowded with macromolecules and organelles that can resist compression. A simple picture describing their behavior is that of colloidal particles; colloids exhibit a sharp increase in viscosity with increasing volume fraction, ultimately undergoing a glass transition and becoming a solid. We investigate the consequences of these 2 competing effects and show that as a cell is compressed by hyperosmotic stress it becomes progressively more rigid. Although this stiffening behavior depends somewhat on cell type, starting conditions, molecular motors, and cytoskeletal contributions, its dependence on solid volume fraction is exponential in every instance. This universal behavior suggests that compression-induced weakening of the network is overwhelmed by crowding-induced stiffening of the cytoplasm. We also show that compression dramatically slows intracellular relaxation processes. The increase in stiffness, combined with the slowing of relaxation processes, is reminiscent of a glass transition of colloidal suspensions, but only when comprised of deformable particles. Our work provides a means to probe the physical nature of the cytoplasm under compression, and leads to results that are universal across cell type.

Time use in clinical encounters: are African-American patients treated differently?

Racial disparities in the process and outcome of health care may be partially explained by differences in time use during outpatient visits by African-American and white patients. This study was undertaken to determine whether physicians use their time in clinical encounters with African-American patients differently than with white patients. This study was a multimethod, cross-sectional study conducted between October 1994 and August 1995 in 84 family practices in northeast Ohio. Participants were 4,352 white and African-American outpatients visiting 138 physicians. Time use during the patient visit was measured by the Davis Observation Code, which categorizes every 20-second interval into 20 different behavioral categories. Among 3,743 white and 509 African-American patients, after adjustment for potential confounders, visits by African-American patients were slightly longer than visits with white patients (10.7 vs. 10.1 minutes, p = 0.027). After further adjustment for multiple comparisons, physicians spent a lower proportion of time intervals with African-American patients as compared to white patients planning treatment (29.0% vs. 32.1%, p < 0.001), providing health education (16.4% vs. 19.7%, p < 0.001), chatting (5.2% vs. 7.6%, p < 0.001), assessing patients' health knowledge (0.8% vs. 1.2%, p < 0.001), and answering questions (5.8% vs. 6.9%, p = 0.002). Physicians spent relatively more time intervals with African-American patients discussing what is to be accomplished (9.3% vs. 7.6%, p < 0.001) and providing substance use assessment and advice (0.8% vs. 0.4%, p = 0.001). In conclusion, physicians spend time differently with African-American as compared with white patients. These differences may represent appropriate tailoring of services to meet unique needs, but could also represent racial bias.

Parenting stress in families of children with disabilities.

Using measures of child and family functioning, this study evaluated levels of parenting stress in 880 families of children with disabilities. Results suggest that factors such as income, time available for interaction with the child, and social support predict parenting stress much better than do aspects of child functioning. Implications for intervention and for future research are discussed.

Effects of mothers' locus of control for child improvement in a developmentally delayed sample.

A potentially important variable that has received little attention in the literature is the locus of control (LOC) a caregiver holds for child improvement, including its influence on the caregiver's treatment compliance and on actual child improvement. In this study, 131 mother-child dyads were assessed across 1 year, to evaluate the utility of the LOC construct in a practice setting. Children were approximately 4 years old at the first assessment, and all of them had been diagnosed with a developmental disability. Mothers' compliance with treatment (mothers' attendance at sessions; teachers' ratings of mothers' support and knowledge) was tracked, and measures of child development status and mothers' locus of control were administered. Statistical results indicated that mothers' locus of control was not significantly correlated with children's gains in development over the year. The mothers' beliefs about whether the child or chance would be responsible for improvement were associated with lower compliance with treatment, whereas the mothers' beliefs that child improvement was attributable to professional intervention were associated with enhanced involvement in treatment.

Systemic adenovirus infection associated with high mortality in mule deer (Odocoileus hemionus) in California.

Seventeen counties in northern California experienced epizootics of high mortality in the mule deer (Odocoileus hemionus) population during the latter half of 1993. Thirteen deer submitted to the California Veterinary Diagnostic Laboratory System as part of this natural die-off had systemic adenovirus infection. Pulmonary edema was present in all 13 deer. Erosions, ulceration, and abscessation of the upper alimentary tract occurred in 7/13 deer. Four of 13 deer had hemorrhagic enteritis. All 13 deer had widespread systemic vasculitis with endothelial intranuclear inclusions. Fluorescein isothiocyanate-labeled antibody directed against bovine adenovirus type 5 bound to antigen in endothelial cells. Adenovirus was identified by transmission electron microscopy within the nuclei of endothelial cells in 6/6 deer examined. An adenovirus was isolated from lung homogenates of one deer that were cultured on black-tailed deer pulmonary artery endothelial cells. With the exception of the intranuclear inclusions evident on histologic evaluation, gross and histologic changes were similar to those described for bluetongue virus infection and epizootic hemorrhagic disease virus infection in white-tailed deer. Nine additional deer were emaciated and had pharyngeal abscesses with focal vasculitis, which may represent the chronic affects of previous nonfatal adenovirus infection.

Experimental reproduction of bovine fetal Neospora infection and death with a bovine Neospora isolate.

Studies were conducted to determine the pathogenic potential of the recently isolated bovine Neospora protozoa (BPA-1) for the bovine fetus. Cows chosen for study had Neospora titers < 160 using an indirect immunofluorescent antibody (IFA) test. Four experimental groups were studied. In group 1, 2 fetuses were inoculated in utero at 118 days gestation with culture-derived Neospora tachyzoites. A pregnant control cow was housed in the same pen, observed daily and screened serologically for evidence of exposure to Neospora. In group 2, 2 cows were infected with Neospora tachyzoites at 138 or 161 days gestation, and 1 control cow was given uninfected cell culture suspension simultaneously at 154 days gestation. Groups 3 (85 days gestation) and 4 (120 days gestation) each consisted of 2 cows infected with Neospora tachyzoites and 1 control cow given uninfected material at the same stage of gestation. Dead fetuses were surgically removed from the infected cows in group 1 on postinfection day (PID) 17. The histopathology was compatible with protozoal fetal infection, and protozoa were identified by immunohistochemistry. Viable fetuses were removed surgically from cows in group 2 on PID 28-30. The histopathology was compatible with protozoal fetal infection, protozoa were identified by immunoperoxidase techniques, and Neospora tachyzoites were reisolated in vitro from tissues of the 2 infected fetuses. In groups 3 and 4, the control fetus and 1 infected fetus were removed surgically between PID 26 and PID 33. The remaining infected cows were observed until fetal death or abortion occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Serologic detection of bluetongue virus infection of black-tailed deer: comparison of serum neutralization, agar gel immunodiffusion, and competitive ELISA assays.

Three adult black-tailed deer (Odocoileus hemionus columbianus) and four fawns were inoculated with bluetongue virus (BTV) serotype 10 or 17, or epizootic hemorrhagic disease virus (EHDV) serotype 1. Animals were bled at irregular intervals thereafter and the presence of virus-specific antibodies in serum determined by agar gel immunodiffusion (AGID), serum neutralization (SN) and competitive enzyme-linked immunosorbent assay (C-ELISA) tests. Serum antibodies to BTV were detected in all three tests for 692 days after inoculation (DAI) of adult deer, but both the SN and AGID tests gave either erroneous or misleading results. Serum from one deer was negative by the AGID test at 409 DAI with BTV-10 but was positive at 248 and 692 DAI; also one adult and one fawn had antibodies by the SN test to serotypes of BTV with which they were not inoculated. The AGID test for EHDV had false positive results with some sera from animals inoculated only with BTV, and it consistently had false negative results with serum samples collected from an EHDV-inoculated deer at 140 DAI and thereafter. The C-ELISA was the most useful test for the detection of antibodies to BTV because it rapidly gave quantitative and accurate results.

A retrospective serologic survey for Anaplasma spp. infection in three bighorn sheep (Ovis canadensis) populations in California.

Using an indirect immunofluorescence assay, we determined the prevalence of Anaplasma-reactive antibody in three herds of bighorn sheep, each a different subspecies and occupying a different habitat in California (USA). Antibodies to Anaplasma spp. were identified in none of twenty California bighorn (Ovis canadensis californiana) sampled from the Mt. Baxter herd, 11 of 17 peninsular bighorn (O. canadensis cremnobates) sampled in the Santa Rosa Mountains, and all 20 desert bighorn (O. canadensis nelsoni) sampled at Old Dad Peak/Kelso Mountains. Based on an assay and an adsorption technique, the titers most likely were due to Anaplasma ovis. The presence and species of tick vectors in each of the habitats, and the presence or absence of deer or livestock were identified as factors potentially influencing seroprevalence of antibodies.

Evaluation of multiple reticulorumen selenium pellets as a health risk in growing Hereford steers.

Five groups of Hereford steers were monitored for 293 days. One group of 3 was not given selenium supplementation; the other 4 groups of 3 steers each were given 2, 4, 6, or 8 reticulorumen selenium pellets. Health, body weight, and blood selenium concentration were monitored during the study. At the finish, steers were slaughtered, and various tissues from the carcasses were analyzed for selenium content. Initial blood selenium concentration did not differ significantly among groups. However, significant (alpha = 0.01) difference among means was detected during the early period of rapid increase in blood selenium concentration in steers of supplemented groups. Means of maximal blood selenium concentration also differed among groups; however, even the highest value, 0.253 micrograms/g, was lower than the 3 micrograms/ml reported in chronic clinical cases of toxicosis in the literature. Carcass analysis indicated significant (alpha = 0.05) differences in selenium concentrations among treatment groups for almost all tissues tested. Only kidney samples (7.9 micrograms/g) from steers of the 8-pellet treatment group exceeded published normal values (7.6 micrograms/g). Health variables for most dates were not significantly different among groups, and selenium toxicosis was not evident in any steer. Analysis did not indicate risk to human beings consuming tissues from these steers.

Compensatory weight gain in steers recovered from oak bud toxicosis.

Cattle that had recovered from clinical oak bud toxicosis (as assessed by normal BUN and serum creatinine values and good appetite) performed better than did clinically normal herdmates when weight gain and feed efficiency were compared. Both groups had a rate of weight gain (oak bud-exposed cattle, 1.76 kg/steer/d; control cattle, 1.57 kg/steer/d) that exceeded the feedlot mean value (approximately 1.4 kg/d) for cattle (of similar starting weight and diet) that had zeranol implants, and the difference was significant (P less than 0.005) for both groups. The difference in weight gain performance of oak bud-exposed cattle, compared with control cattle, was not highly significant; however, the improved feed efficiency was significantly (P less than 0.05) better than that in controls (2.57 kg of feed/kg of weight gain vs 3 kg of feed/kg of weight gain). On the basis of accepted criteria (increased rate of weight gain and efficiency of feed conversion), the group of oak bud-exposed cattle of this study had compensatory weight gain. Thus, cattle with good evidence of clinical recovery from oak bud toxicosis can be expected to perform in the feedlot at least as well as cattle not exposed to oak bud toxicosis, and may have compensatory weight gain.

Prevention of clinical coliform mastitis in dairy cows by a mutant Escherichia coli vaccine.

A prospective cohort study was undertaken in two commercial California dairies. The treatment group, 246 cows, received three doses of a whole cell bacterin of J5 Escherichia coli (mutant of E. coli O111:B4) plus Freund's incomplete adjuvant vaccine (two in the dry period and one after calving) while 240 unvaccinated cows served as controls. Thirty-five cases of clinical coliform mastitis were diagnosed, six in vaccinated cows and 29 in unvaccinated cows. Bacteria isolated from the clinical cases included 15 E. coli five Klebsiella pneumoniae, three K. oxytoca, three K. ozaenae, five Enterobacter aerogenes, three Serratia marcescens and one Serratia spp. Four control cows were culled, three of them because of chronic coliform mastitis and one because of postcoliform infection agalactia. Incidence rate of clinical gram-negative mastitis was 2.57% in vaccinated cows and 12.77% in unvaccinated cows. The estimated risk ratio, the measure of risk of having clinical gram-negative mastitis for vaccinated cows to unvaccinated cows, was 0.20 (p less than 0.005), indicating a strong relationship between vaccination and lack of clinical gram-negative mastitis. The results of this trial indicate that the administration of the E. coli J5 vaccine is protective against natural challenge to gram-negative bacteria, and reduces the incidence of clinical gram-negative mastitis in dairy cows during the first three months of lactation.

Oak toxicosis in cattle in northern California: clinical and pathologic findings.

Sixteen calves (3 to 8 months old) affected with oak toxicosis were studied. Clinical, laboratory, and pathologic findings during the peracute through chronic stages were documented. Of the calves studied, 1 died, and 9 others were euthanatized because death was imminent. To evaluate chronic effects, the 6 remaining cattle were euthanatized after 2 months. One calf with acute toxicosis was treated successfully with diuretics and fluid volume replacements containing sodium chloride and calcium. Clinical and laboratory data were compared between survivors and nonsurvivors. A statistically significant (P less than 0.02) difference was found only in serum creatinine concentration at the time of initial reexamination. A decrease in BUN and creatinine values during the next 7 days and the lack of anorexia after the acute phase were the best prognostic indicators for survival.

Studies on the pathogenesis of epizootic bovine abortion.

Ornithodoros coriaceus Koch ticks were fed on 37 pregnant cows. The fetuses were obtained from the cows at 23 to 126 days after maternal tick exposure. Characteristic lesions of epizootic bovine abortion were observed only in those fetuses recovered 100 days more or after maternal tick exposure. Fetuses collected between 50 and 100 days showed mild-to-moderate lymphoid and mononuclear cell hyperplasia. Reaction in fetuses studied less than 50 days after maternal tick exposure were mild. Lesions could not be seen in 2 of the youngest fetuses. Increases in serum immunoglobulin concentrations were present only in those fetuses examined 80 days or more after their dams had been exposed to ticks. The specificity of the immunoglobulins could not be determined. Sera from 12 fetuses tested failed to fix complement in tests for group-specific chlamydial antibodies. A wide variety of microbiological cultivation attempts were made to recover the causative agent of epizootic bovine abortion from these fetuses; however, no agent was recovered regularly, and chlamydial organisms were not recovered from any. The significance of 2 recovered agents, apparently viral, is still to be determined. Fetal tissues, both frozen and fresh, collected from fetuses of dams exposed to a feeding of ticks were capable of reproducing the disease after inoculation into pregnant cows or directly into fetuses.

Seasonal occurence of infective nematode larvae on irrigated pasture grazed by cattle in California.

During the period extending from Dec 1, 1975, to Dec 22, 1976, 3 distinct peaks in the concentration of infective nematode larvae on pasture forage were detected by use of helminth-free tracer calves. Two of these peaks, 1 occurring in the spring and 1 in the fall, consisted mainly of Ostertagia ostertagi and Cooperia sp. It is concluded that these 2 peaks can be anticipated annually and constitute unsafe periods of grazing. The 3rd peak was comprised largely of Haemonchus placei and Cooperia sp. It is concluded that this peak occurred as the result of unusual rainfall and reduced evaporation in August. Arrested developed (24% to 30%) of O ostertagi larvae occurred only during the spring peak. This finding indicates that on irrigated pastures in California, type I ostertagiasis can be expected to occur as the result of infection during the spring and/or fall peaks, whereas type II ostertagiasis can be expected to occur in the fall as a result of infection obtained during the spring peak. Arrestment in development of Cooperia sp occurred during spring (14%) and fall (23%) peaks. Haemonchus placei larvae increased their propensity for arrestment in development from zero to 82% during the months following the peak level of infection in summer. Other nematodes encountered were Trichostrongylus axei and Nematodirus helvetianus.