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Biomedical subjects

R D Walker

Publications and source records attributed to R D Walker.

At least 181 records · Page 10Linked to original sources
PubMed1981

Patterns of oral bacterial infection in captive snakes.

The bacterial isolates from culture specimens of snakes with infectious stomatitis were compared with those from culture specimens of the oral cavity of healthy captive snakes. Cloacal swab specimens were also taken from healthy snakes to compare their intestinal and oral bacterial populations. The healthy snakes had a predominantly gram-positive oral flora, with Corynebacterium spp and coagulase-negative Staphylococcus spp being the organisms isolated most frequently. The specimens from snakes with infectious stomatitis yielded predominantly gram-negative bacteria. The organisms most frequently isolated from these specimens were Pseudomonas aeruginosa, Providencia rettgeri, and P maltophilia. The cloacal swabbing of healthy snakes also resulted in the isolation of predominantly gram-negative organisms, suggesting that these bacteria are not exogenous pathogens but opportunistic invaders.

Animals↗
PubMed1981

Prevention of urethral strictures in the management of posterior urethral valves.

Our 28 patients with posterior urethral valves managed with transurethral resection have sufficient followup to evaluate the development of urethral strictures. Of these 28 patients 14 were less than 1 year old when the valves were resected and strictures developed in 7 (50 per cent). Of the 14 patients who were more than 1 year old when the valves were resected none had a stricture. Within the latter group was a subgroup of patients who were treated with early vesicostomy and later valve resection. None of these patients suffered a stricture. Our data indicate that stricture formation is high when valve resection is attempted in the neonate or small infant and can be prevented by primary vesicostomy and delayed valve resection.

Adolescent↗
PubMed1980

Cell-mediated immunity against herpes simplex induction of cytotoxic T lymphocytes.

The conditions required for the induction of both primary cytotoxic T lymphocytes (CTL) in vivo and secondary CTL in vitro against herpes simplex virus type 1 (HSV-1)-infected cells were defined. Primary CTL responses occurred only in mice exposed to infectious HSV-1. These responses, which were shown to be mediated by T lymphocytes, peaked at 1 week and had disappeared by 2 weeks after infection. The level of primary cytotoxicity was enhanced by treatment of mice with cyclophosphamide before infection. Secondary in vitro CTL responses were more pronounced and were induced by some forms of inactivated virus as well as by infectious HSV-1. Thus, both ultraviolet light- and glutaraldehyde-inactivated preparations of HSV-1 induced CTL, but heat-inactivated and detergent-extracted antigens failed to do so. The reasons for the differing efficiency of infectious and noninfectious HSV-1 for induction of CTL are discussed.

Animals↗
PubMed1980

Urinary tract infections in children: effect of short course antibiotic therapy on recurrence rate in children with previous infections.

Eighty-five girls, ages 3-16, with a past history of recurrent urinary tract infections were treated for 10 days with either trimethoprim/sulfamethoxazole, ampicillin or cephalexin. Patients with normal roentgenograms as well as those with reflux and cortical scarring were included. In the 12 weeks following completion of treatment, a significantly lower recurrence rate was noted in children who received trimethoprim/sulfamethoxazole. There was no difference in the recurrence rate whether or not radiographic abnormalities were present. No serious side effects were noted with any drug regimen.

Adolescent↗
PubMed1980

Study of bovine pulmonary response to Pasteurella haemolytica: specificity of immunoglobulins isolated from the bovine lung.

A procedure is described for the isolation and purification of the immunoglobulins (Ig)A and IgG from pulmonary lavage fluid from calves. These Ig were isolated from calves experimentally exposed to Pasteurella haemolytica via aerosolization and from nonexposed calves. The specificity of these fractions toward P haemolytica was examined, using an indirect fluorescent antibody test and agglutination reactions. Specific antibody activity was detected in the IgA and IgG fractions from calves exposed to P haemolytica and IgG fractions from nonexposed calves. None of the isolated Ig agglutinated P haemolytica.

Agglutination Tests↗
PubMed1980

Study of bovine pulmonary response to Pasteurella haemolytica: pulmonary macrophage response.

A resistance state was produced in the bovine lung by exposing calves to an aerosolized mist of Pasteurella haemolytica. Verification of the resistant state was determined by an increase in clearance of P haemolytica from lungs of exposed calves vs lungs from nonexposed calves over 24 hours. Bovine pulmonary macrophages isolated from lung washings of calves exposed to P haemolytica and from lungs of nonexposed calves failed to phagocytize P haemolytica in vitro. Whole serum, pulmonary immunoglobulin (Ig) A, and IgG from exposed and nonexposed calves did not enhance phagocytosis as measured by 14C uptake or fluorescent antibody staining.

Aerosols↗
PubMed1979

Application of discriminant analysis to level of performance of alcoholics and nonalcoholics on Wechsler-Bellevue and Halstead-Reitan subtests.

Investigated the utility of subtests from the Wechsler-Bellevue Intelligence Scale and the Halstead-Reitan Neuropsychological Test Battery to differentiate between alcoholics and nonalcoholics (N = 76). Analyses of variance indicated that the alcoholics were more impaired than nonalcoholics. It was found that the Wechsler-Bellevue Performance subtests were more discriminative than were Verbal subtests, with performance on the Halstead-Reitan variables being intermediate. The nine measures that differentiated most significantly between groups were subjected to a stepwise multivariate discriminant analysis. The resulting function correctly classified Ss with an overall accuracy of 74.7%. It was found that the Block Design subtest was the best single discriminator. The findings were discussed in relationship to previous findings and with respect to general issues of clinical neuropsychological assessment.

Alcoholism↗