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Biomedical subjects

H F Stills

Publications and source records attributed to H F Stills.

30 records · Page 2Linked to original sources

Malignant lymphoma in a Sinclair miniature pig.

Malignant lymphoma was diagnosed in a 3-year-old, male Sinclair(S-1) miniature pig with acute anorexia, depression, fever, and markedly enlarged inguinal lymph nodes. Results of an initial hemogram indicated a leukocyte count of 121,489 cells/mm3. Most of the leukocytes were mononuclear cells of various sizes, nuclear chromatin pattern, number of nucleoli, amount of cytoplasm, and amount of staining. Cytochemical staining and flow cytometric evaluation of the leukocytes indicated a large number of hypodiploid lymphoblasts in the peripheral blood. Gross necropsy findings included enlargement of all lymph nodes, a pale liver, and multifocal pale areas scattered throughout the kidneys. Microscopic examination indicated massive infiltration of abnormal lymphoid cells into most major organs and complete loss of normal morphologic features of all lymph nodes.

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Naturally occurring Yersinia enterocolitica septicemia in patas monkeys (Erythrocebus patas).

Two cases of Yersinia enterocolitica septicemia occurred in a breeding group of 22 adult patas monkeys (Erythrocebus patas). Affected animals had acute clinical signs of depression, weakness, dehydration, hypothermia, hepatomegaly and pronounced leukopenia. Both animals died a few hours after treatment was initiated. Gross necropsy findings included jaundice, fluid in body cavities, hepatomegaly, splenomegaly, multiple white foci within the liver and spleen, generalized lymph node enlargement and numerous mucosal ulcerations in the colon. Primary histopathological lesions were multifocal hepatic necrosis, splenic necrosis, chronic ulcerative enteritis and diaphragmatic myositis with necrosis and edema. Yersinia enterocolitica was cultured from the liver, spleen, lung, jejunum and rectum. Wild rodents, particularly mice, may have been a source of infection for these animals, as the monkeys were housed in a rural, indoor-outdoor facility. A preliminary culture survey showed that some clinically normal patas monkeys harbored the organism in their intestinal tracts.

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Cell-mediated immune reactivity of Sinclair melanoma-bearing swine to 3 M KCl extracts of swine and human melanoma.

Leukocyte migration inhibition (LMI) assays were performed using 3 M KCI extracts to detect cell-mediated immune reactions against tumor-associated antigens (TAA) of swine melanoma. Positive LMI reactivity was 70% or greater in melanoma-bearing swine compared to 10% reactivity or less in normal swine tested with extracts of either fresh or tissue-cultured swine melanoma cells. Positive LMI reactivity was 10% or less in both melanoma and normal swine tested with extracts of normal fetal and adult swine tissues. Extracts of tissue-cultured swine melanoma and human melanoma cells were equally capable of stimulating positive LMI reactivity in melanoma swine and human melanoma patients; normal swine and human donors demonstrated 10% or less positive LMI reactivity to these extracts. Positive LMI reactivity was not stimulated in swine melanoma or human melanoma donors by extracts of tissue-cultured human breast tumor cells or fresh and tissue-cultured mouse B16 melanoma cells. Evaluation of these results indicate that melanoma-bearing swine develop cell-mediated immune reactivity toward TAA on swine melanomas and, inasmuch as LMI assays were performed with allogeneic extracts, suggests the presence of common TAA on swine melanomas. Furthermore, these data suggest that swine and human melanoma cells may share some common TAA and that this common TAA is not expressed on mouse B16 melanoma cells.

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Increased atherosclerosis and glomerulonephritis in cynomolgus monkeys (Macaca fascicularis) given injections of BSA over an extended period of time.

A study was conducted to compare the effects of experimental immune complex disease on the development of glomerulonephritis and aortic and coronary artery atherosclerosis. Fourteen adult male macaques (Macaca fascicularis) were fed a mildly atherogenic diet. Ten of these animals were given repeated intravenous injections of bovine serum albumin (BSA), and the remaining 4 were given similar injections of saline. Three of the monkeys given BSA responded with a high antibody titer, 4 with a moderate titer, and 3 with a low level titer to BSA. In all 4 monkeys with the moderate antibody response glomerulonephritis developed, characterized by increased glomerular cellularity, electron-dense deposits in the glomerular capillary basal lamina, and deposits of IgG, IgM, C3, C4, and BSA. Glomerulonephritis was not seen in the other 6 monkeys given BSA or the 4 control monkeys. Aortic lesions seen at necropsy consisted of a few fatty intimal streaks with no differences between test monkeys (given BSA) and control monkeys (given saline). There was no correlation between total serum cholesterol concentration, high-density lipoprotein cholesterol concentration, or BSA antibody levels and the degree of aortic atherosclerosis. Immunochemical stains for immunoglobulins and complement components revealed increased intimal staining when intimal thickness increased. Medial staining for immunoglobulin and complement components appeared to be slightly increased in monkeys with moderately high-level titers of BSA. The extent of atherosclerosis in the coronary arteries of monkeys given BSA was greater than in the control animals. Differences in the extent and severity of the atherosclerotic lesions were most pronounced in the proximal portions of the main coronary arteries, suggesting an increased susceptibility of this site to immune-complex-exacerbated atherosclerosis. In addition to the increased lesion severity in monkeys given BSA, there were numerous granulocytes seen within, attached to, and penetrating into the intima of the coronary lesions. No correlation was seen between the development of glomerulonephritis and either aortic or coronary artery atherosclerosis.

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Campylobacter jejuni isolated from patas monkeys with diarrhea.

Campylobacter jejuni was isolated from 11 (46%) of 24 patas monkeys with chronic diarrhea. Eight of these 11 (73%) monkey were characterized clinically by mucohemorrhagic diarrhea for periods up to a month followed by loose, semi-formed feces for a 12-month period. Half of the monkeys were treated with erythromycin for 10 days and the other half with tetracycline for 10 days, with all responding to treatment. Despite treatment, all monkeys again had an outbreak of mucohemorrhagic diarrhea. Biopsy specimens were taken from all eight monkeys over a period of 3 months. The clinical signs, treatment, and the gross and microscopic lesions seen in these monkeys were similar to those reported in humans and animals infected with Campylobacter jejuni.

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Congenital defects of squirrel monkeys (Saimiri sciureus).

Nine congenital defects were seen in six animals during necropsies of 27 aborted or stillborn and 25 neonatal squirrel monkeys (Saimiri sciureus) during a two-year period. The defects were left diaphragmatic hypoplasia with herniation; right renal aplasia in conjunction with a right cleft lip and primary palate; supernumerary left kidney; skeletal defects, hydrocephalus, and thyroid anomalies consistent with the campomelic syndrome; atresia ani; and ultimobranchial gland remnants. The high incidence of congenital anomalies (4.9% of births and 11.5% of nonsurviving births) is consistent with a previous report of congenital defects in squirrel monkeys.

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Renal disease in squirrel monkeys (Saimiri sciureus).

Renal lithiasis, pyelonephritis, and glomerulonephritis were common in our colony of Brazilian phenotype squirrel monkeys (Saimiri sciureus), with glomerulonephritis being a major cause of mortality in adult animals. Squirrel monkey glomerulonephritis was divided into four major classifications, based on light and electron microscopy, similar to those of man: focal sclerosing glomerulonephritis, membranoproliferative glomerulonephritis, membranous glomerulonephritis, and a combination of membranoproliferative and membranous glomerulonephritis.

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A comparison of bacterial flora isolated by transtracheal aspiration and pharyngeal swabs in Macaca fascicularis.

The pulmonary flora of 30 monkeys (Macaca fascicularis) was sampled by the transtracheal aspiration technique and the pharyngeal swab method, and the results were compared. The transtracheal aspiration technique yielded lower numbers of bacteria in both aerobic and anaerobic cultures. The bacteria isolated by transtracheal aspiration were predominately pure culture, thereby lowering the possibility of contamination from commensal flora. Bordetella bronchiseptica was isolated from 23.3% of the monkeys by transtracheal aspiration, but this organism was not isolated when samples were collected with pharyngeal swabs.

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Calcium-restricted ovariectomized Sinclair S-1 minipigs: an animal model of osteopenia and trabecular plate perforation.

The ovariectomized rat model has now been generally accepted as a useful model for screening different therapeutic agents, but there is a major requirement to identify reliable large animal models for osteoporosis research. In this study, the calcium restricted, ovariectomized minipig has been thoroughly investigated in order to define a large animal model with trabecular and cortical bone remodeling which would be reliable for further testing of agents that had shown promise of efficacy during the screening procedure. Twenty six female, 4-month old minipigs were randomized into four groups and fed either normal diet (0.90% calcium (Ca.)) or diet with restricted calcium content (0.75%, 0.50%). At the age of ten months, 3 groups were ovariectomized (OVX) while one group on normal diet was shamoperated. The groups were followed for six months after the operation. At death, bone mass was determined by densitometry and by ashing. Additionally, biomechanical competence was assessed in trabecular bone cores from the vertebral bodies. Finally, histomorphometry (static and dynamic parameters) and structural analyses (star volume) were performed on the vertebral bodies. The study revealed an OVX-related decline of 6% in vertebral bone mineral density (BMD) and a decline of 15% in trabecular bone volume (BV/TV). In contrast, a 15% increase in mean trabecular plate separation (Tb.Sp.) and a small increase in marrow space star volume (Ma. Star V.) were detected. The structural changes became more pronounced when OVX was combined with mild Ca. restriction (0.75% Ca.) with an increase in Ma. Star V. to 164%.(ABSTRACT TRUNCATED AT 250 WORDS)

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