Biomedical subjects
Publications and source records attributed to B McCullough.
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Pulmonary fibrosis was induced in eight baboons with bleomycin; five untreated animals were controls. After 45-65 U/kg of bleomycin, lung volumes and diffusing capacity were reduced, and static lung pressure-volume curves were shifted to the right. Right middle lobes were resected at this time in five bleomycin-treated and two control animals. Compared to controls, right middle lobes from bleomycintreated animals had increased weight and contained increased amounts of total protein, collagen, elastin, and DNA; synthesis of collagen and noncollagen protein were also elevated. Occasional alveolar septae were edematous and infiltrated by mononuclear inflammatory cells; a slight increase in collagen was demonstrable histologically. Four of six treated animals died with extensive diffuse interstitial fibrosis after 95 U/kg of bleomycin. Biochemical analyses revealed significantly elevated lobar contents of dry weight, protein, elastin, and collagen. Two animals survived 95 U/kg of bleomycin and were terminated 6 mo after treatment. In these animals, physiologic studies were indicative of restrictive lung disease, but lung histology was nearly normal. Lung weight, total protein, and DNA had returned to control values, but collagen and elastin were increased in amount and concentration. Bleomycin induces an intense inflammatory response in the lung. During this inflammation, connective tissue proliferation occurs in concert with proliferation of other tissue components. Cessation of bleomycin treatment is followed by resolution of inflammation manifested by decreases in tissue mass, cellular content, and nonconnective tissue protein. Collagen and elastin deposited during inflammation are less successfully removed during resolution, leading to a stage characterized by increased concentrations of these proteins. A similar sequence of tissue alterations may occur in idiopathic diffuse interstitial fibrosis of man in response to various lung injuries.
Two young chimpanzees (Pan troglodytes) and two adult gibbons (Hylobates lar), each exposed to 1,000 cercariae of Schistosoma intercalatum (Cameroon), were examined at 79 and 82 wk and 61 and 69 wk, respectively, post-infection. Based upon worn returns and tissue egg deposits, these primates can be employed as hosts for experimental schistosomiasis intercalata. However, no histopathology was detected in the urogenital system.
Specimens of ventral prostate from 37- to 46-month-old Andradurin-treated A X C rats demonstrated three primary morphologic patterns, each being divisible into two sub-groups based upon the extent of glandular alteration. The principal groups were: group 1, hyperplasia; group 2, atypical hyperplasia; and group 3, adenocarcinoma. The secondary classifications were: subgroup (+), few glands involved; and subgroup (++), most glands involved. Multiple parameters of ventral prostate testosterone metabolic potential failed to distinguish the morphologically diverse prostate specimens of groups (1+). 1(++), 2(+), 2(++), and 3(+) which predominantly metabolized testosterone to 5alpha-reduced 17beta-hydroxysteroids. By contrast, testosterone metabolism by ventral prostate specimens predominantly composed of neoplastic epithelium, group 3(++), was distinct from all other prostate specimens. The distinguishing feature was a shift to more prominent elaboration of 17-ketosteroids, principally delta4-androstenedione, and a cteroids. The change in this biochemical parameter of prostate epithelial cell function was indicated to be an early manifestation of the neoplastic transformation.
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Candidiasis involving nasal, pharyngeal, and intestinal mucosal surfaces and a pharyngeal lymph node was demonstrated microscopically in a young adult female capuchin monkey (Cebus apella) experimentally infected with Schistosoma haematobium (Iran strain). Persistent nasal exudation and weight loss characterized the clinical disease preceding the animal's death.
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The pathogenicity of a strain of simian herpesvirus SA8 in one month old conventional and gnotobiotic baboons was investigated. Intratracheal inoculation resulted in a mortality rate of 1/5 in the conventional and 1/4 in the gnotobiotic group. Disease became apparent after 3 days and was characterized by respiratory distress, reduced formula intake, weight loss and fever in both groups. Isolation of herpesvirus from the respiratory tract, lymphoid organs, kidneys, adrenals, and CNS was more frequent by explant culturing than by routine procedures. Although there was a significant difference in total white blood counts (WBC), with higher values in conventional vs. gnotobiotic infants, the absolute number of lymphocytes was not different. The lower number of WBCs apparently was due to fewer polymorphonuclear leukocytes in the gnotobiotic baboons. Infection resulted in a leukopenia 5 days post infection (p.i.) and a leukocytosis 10 days p.i. in both groups. The animals, which succumbed, had acute necrotizing fibrinous pneumonia. Intranuclear inclusion bodies typical for herpesviruses were present. All the surviving infant baboons had subacute interstitial pneumonia, when sacrificed 35 days p.i.
The humoral immune response to canine distemper viral antigens in gnotobiotic dogs experimentally infected with canine distemper virus was studied by the complement fixation and serum neutralization tests. Antibody titers measured by both serologic methods varied inversely with the severity of disease produced. Recovered dogs demonstrated the highest titers of antibody, whereas fatally infected dogs had little or no antibody activity in their sera. A third group of dogs, characterized by chronic persistent infection, had intermediate levels of anitbody to canine distemper virus. Preliminary characterization of the viral antigens involved in the complement fixation test indicated that at least two antigenic components were involved. One antigen was soluble in ether and was heat-labile, whereas the other was relatively heat-stable and was unaffected by treatment with ether. No evidence for serologic cross-reaction between viral and central nervous system components was found. A vigorous antibody response to envelope antigen determinants in addition to core determinants distinguished immune dogs from persistently infected dogs. The results of this study suggest that the inability to produce antibodies to envelope antigens may be a crucial factor in the establishment of a persistent infection with canine distemper virus in these dogs.
Spontaneous adenocarcinomas of the ventral prostate were present in 7 of 41 aged (34- to 37-month-old), virgin, untreated male A X C rats. The only consistent gross evidence of possible neoplastic involvement was intraprostate hemorrhage. The principally intraglandular neoplasms were composed of markedly anaplastic epithelial cells which retained a moderate propensity to form glandular patterns. The nuclei of the neoplastic cells were pleomorphic, vesiculated, enlarged, and hyperchromatic. Mitotic figures were frequent. Interglandular connective tissue was invaded in one rat; however, metastases were not demonstrated.
Oncorna-like virus particles were observed in prostate tissue of 2 of 11 baboons inoculated 3 years previously with a chemical carcinogen. There were no indications, however, of any relationship between the carcinogen and the development of virus particles. Biopsy specimens from the animals showed no evidence of neoplasia, and electron microscopic examination suggested that this virus should be categorized as a B-type oncornavirus.
Nocardia caviae was identified as the causative agent of draining, multinodular swelling of the hand of a 16-yr-old female baboon (Papio cynocephalus). The baboon's general physical condition was poor and menstrual cycles had ceased. The baboon improved after systemic and topical antibiotic therapy, but the lesion recurred after antibiotic treatment was discontinued. Since excision of the mass, the baboon's physical condition has improved to the extent that regular menstrual cycles have resumed and she has been returned to the assigned investigative program. Radiographs of the lungs, hand, and arm failed to disclose evidence of dissemination of the infection.
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