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C C Brown

Publications and source records attributed to C C Brown.

189 records · Page 11Linked to original sources
PubMedDate not supplied

A review of three pathology-based techniques for retrospective diagnosis of rinderpest, with comparison to virus isolation.

Base of tongue, eyelid, and retropharyngeal lymph node were collected from three animals experimentally infected with rinderpest and utilised in a study comparing virus isolation with histopathology, immunohistochemistry, and in situ hybridisation to determine the usefulness of the latter three techniques as retrospective diagnostic aids for this disease. Virus isolation was positive for all nine samples. Histopathology was suggestive in all the tissues and definitive in some. Immunohistochemistry and in situ hybridisation highlighted the presence of rinderpest antigen of rinderpest nucleic acid in all of the sections. However, in situ hybridisation was more specific than immunohistochemistry.

Animals↗
PubMedDate not supplied

Odor identification in young and elderly African-Americans and Caucasians.

Olfactory function is affected by age and gender. However, there are few data on smell function in various racial/cultural groups, in particular, in different-aged African-Americans. Therefore, this study sought to determine if there is a relationship among age, gender, and race for smell identification. Sixty healthy African-Americans and 60 Caucasians between the ages of 20-40 and 60-80 years were administered the University of Pennsylvania Smell Identification Test (UPSIT). Older persons, regardless of race, had lower UPSIT scores, were more likely to be microsmic and anosmic, and had increased chemosensory complaints. Smell performance among females was better compared with males. Overall, African-Americans had lower UPSIT scores and age- and gender-adjusted percentile rank scores compared with Caucasians, but these differences were significant only among younger subjects. In addition, both young and old African-Americans had no smell complaints. The results from this study suggest that age, gender, and race have an influence on smell identification.

Adult↗
PubMedDate not supplied

Semen quality and human fertility: a prospective study with healthy couples.

Measures of semen quality are used as surrogate measures of male fertility in clinical andrology, reproductive toxicology, epidemiology, and risk assessment. However, only limited data are available to relate those measures to fertility. This prospective study with 210 reproductive-age couples was conducted to provide information on the value of semen quality measures for predicting human male fertility potential and for development of models to estimate the effects of changes in semen quality on fertility in a given population for risk assessment. Couples without known risk factors for infertility and who had discontinued contraception to have a child were accepted. The study followed each couple for up to 12 menstrual cycles while they attempted to conceive and evaluated semen quality measures from multiple ejaculates per man with known abstinence intervals. For each cycle, the day of ovulation was predicted, and the couple was advised to have intercourse multiple times on that day and on the days around it. Among the demographic variables assessed, parity, contraception status prior to entering the study, male education level, and male smoking were associated significantly with 12-cycle pregnancy rate. Several semen quality measures also were associated significantly with pregnancy rate, with percentage morphologically normal sperm by strict criteria and measures involving total number of sperm showing particularly strong associations. Localized regression-smoothing plots of semen quality data against proportion of couples pregnant suggested levels below which fertility declines for several semen quality measures. These results have applications in both clinical andrology and in assessment of risk to male fecundity from environmental or pharmaceutical exposures. In particular, they contribute information on behavior of fertility with varying semen quality and can allow development of models to predict effects on fertility in populations from decrements in semen quality.

Adult↗
PubMedDate not supplied

Detection of infectious bursal disease virus in experimentally infected chickens by in situ hybridization.

In situ hybridization was used in a pathogenesis study of three vaccine pathotypes (Delaware variant A, D78, and BursaVac) of infectious bursal disease virus (IBDV). Tissues were excised (bursa, thymus, spleen, proventriculus, and cecal tonsils), fixed in formalin, and paraffin embedded at 12, 24, 48, 72, and 120 hr postinoculation (HPI). With an antisense VP2 gene probe, viral nucleic acid was detected in bursas from both D78- and BursaVac-infected chickens at 24, 48, 72, and 120 HPI. However, viral RNA was detected only in the Delaware variant A-infected birds at 72 HPI. Thymus and spleen were positive in the D78-infected birds at 48 HPI and in the BursaVac-inoculated group at 72 HPI. Viral nucleic acid was not present in detectable levels among any of the tissues tested at 12 HPI. However, by 24 hr, scattered positive lymphoid cells were visualized in the bursal follicles of chickens infected with D78 and BursaVac. In addition, low levels of viral nucleic acids were detected in the thymus and spleen among the D78- and BursaVac-infected birds. The sites of viral replication were consistent between the two vaccine-infected groups (D78 and BursaVac), whereas the chickens infected with Delaware variant A had limited IBDV replication in the bursa.

Animals↗
PubMedDate not supplied

Virulence of pigeon-origin Newcastle disease virus isolates for domestic chickens.

The virulence of six pigeon-origin isolates of Newcastle disease virus (NDV) was evaluated before and after passage in white leghorn chickens. Four isolates were defined as pigeon paramyxovirus-1 (PPMV-1) and two isolates were classified as avian paramyxovirus-1 (APMV-1) with NDV monoclonal antibodies. The four PPMV-1 isolates were passaged four times in chickens, and the APMV-1 isolates were passaged only once. Infected birds were monitored clinically and euthanatized. Tissues were collected for histopathology, in situ hybridization with a NDV matrix gene digoxigenin-labeled riboprobe, and immunohistochemistry with an anti-peptide antibody to the nucleoprotein. Mean death time, intracerebral pathogenicity index, and intravenous pathogenicity index tests performed before and after passage in chickens demonstrated increased virulence of the passaged PPMV-1 isolates and high virulence of the original isolates of APMV-1. Sequence analysis of the fusion protein cleavage site of all six isolates demonstrated a sequence typical of the virulent pathotype. Although the pathotyping results indicated a virulence increase of all passaged PPMV-1 isolates, clinical disease was limited to depression and some nervous signs in only some of the 4-wk-old specific-pathogen-free white leghorns inoculated intraconjunctivally. However, an increased frequency of clinical signs and some mortality occurred in 2 wk olds inoculated intraconjunctivally with passaged virus. Histologically, prominent lesions in heart and brain were observed in birds among all four groups inoculated with the PPMV-1 isolates. The behavior of the two pigeon-origin APMV-1 isolates when inoculated into chickens was characteristic of velogenic viscerotropic NDVs and included necro-hemorrhagic lesions in the gastrointestinal tract.

Amino Acid Sequence↗
PubMedDate not supplied

Toe temperature change: a measure of sleep onset?

In an attempt to provide a more "physiological" measure of sleep onset, temperature of the great toe was monitored for 166 sleeper-nights in both insomniac and control groups. All subjects were women between 21 and 45 years of age. Earlier published reports had suggested that toe temperature elevation was the result of lowered sympathetic tone and marked a "vegetative preparedness for sleep." More recently, elevation of the toe temperature has been used to denote a level of chemical anesthesia sufficient for major surgery. In this study, however, the mean latency of the time course of the temperature elevation of the toe was uncorrelated with sleep onset determined by EEG criteria. Temperature elevations were frequently of large magnitude but were not uniformly observed across all subjects and all nights. It is suggested that the toe temperature elevation is reflective of metabolic adjustments which coincide with the onset of the night's first period of slow wave sleep.

Adult↗