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Biomedical subjects

R M Jacobs

Publications and source records attributed to R M Jacobs.

At least 91 records · Page 5Linked to original sources
PubMed1984

Use of a microtiter Coombs' test for study of age, gender, and breed distributions in immunohemolytic anemia of the dog.

Sixteen of 17 dogs with immunohemolytic anemia had a microtiter Coombs' test titer greater than or equal to 1:64. Performance of the test as a hemagglutination assay apparently increased the sensitivity of the test. Three of the dogs with immunohemolytic anemia were sexually intact females, 11 were spayed females, and 3 were sexually intact males. When age and gender were considered together, females were 4.3 times more likely to have immunohemolytic anemia than were males (P less than 0.05). When corrected for population age distribution, spayed females were not predisposed to the problem.

Age Factors↗
PubMed1983

Effects of dietary zinc, manganese, and copper on tissue accumulation of cadmium by Japanese quail.

The beneficial effects of a combined dietary supplement of Zn, Cu, and Mn in decreasing Cd absorption was previously reported. The purpose of this study was to investigate the individual and combined effects of these three elements. In the first two experiments, day-old Japanese quail were fed basal diets containing either requirement amounts of Zn (30 ppm) and Mn (12 ppm) and slightly above requirement levels of Cu (5 ppm). From Day 7 birds were fed either the basal diet or diets containing combinations at twice these concentrations; a 2 X 2 X 2 factorial design was used. 109Cd content and Cd concentration of these diets were 100 mu Ci and 145 micrograms/kg, respectively. In the third experiment, day-old birds were fed either the basal diet or a basal diet containing 109Cd and single additional supplements of either Zn, Cu, or Mn. All birds were killed at 14 days of age. The Cd concentration was determined for the duodenum, jejunum-ileum, liver, and kidney. When the experimental diets were fed for 7 days, only Zn had a protective effect against Cd. Whereas none of the elements reduced the Cd concentration of the duodenum, Zn reduced the Cd in the jejunum-ileum, liver, and kidney by approximately 66, 21, and 11%, respectively. Cu and Mn caused occasional increases of Cd in some tissues. Feeding the experimental diets for 2 weeks resulted in similar responses. Zn nutrition appears to play an important role in protecting against dietary Cd absorption.

Animals↗
PubMed1982

Diseased dogs isoamylases in clinically normal and diseased dogs.

Isoamylases in normal canine sera were separated on cellulose acetate membranes using a discontinuous buffer system without EDTA. Four peaks of amylase activity were present in 17 of 24 sera. Normal values were established. The majority of activity was present in Peak 4 (cathodal isoamylase). Tissue extracts of pancreas, duodenum, kidney, lung, testis, spleen and uterus-ovaries contained Peak 4 isoamylase. Liver and salivary gland lacked all isoamylase activity. Pancreas contained Peak 3 in addition to Peak 4 isoamylase. A tissue origin for Peaks 1 and 2 was not identified. An overall lack of resolution resulted from the inclusion of EDTA in the electrophoresis buffer system. This may account for previous findings suggesting that pancreatic amylase is not present in normal canine serum. An increase in the Peak 3 isoamylase was present in dogs with pancreatitis while dogs with pancreatic atrophy had a decrease in all isoamylases. Total amylase activity was significantly (p < 0.05) decreased in dogs with pancreatic atrophy.

Journal Article↗
PubMed1981

Histocytology of lymphoid tumors in the dog, cat and cow.

In a retrospective study of lymphomas in animals, tumors in 72 dogs, 81 cats and 90 cows were classified on the basis of cell size (small, medium and large), nuclear cleavage (follicular center cells), and histologic architecture (nodular or diffuse). Each subtype was classified by age of animal at death, number of metastases, breed, and sex. As in man, nodular cleaved tumors are rare in animals, the cow having the most varied tumor types. There was one cleaved-cell tumor in 72 lymphomas in dogs, 23 of 81 in cats, and 33 of 90 in cows. There were six nodular tumors of 72 in dogs, two of 81 in cats and eight of 90 in cows. Fifteen of 16 nodular lymphomas had noncleaved cells and twelve had small or predominantly small cells. Cats with nodular lymphomas were older at death than cats with diffuse lymphomas. Nodularity was not associated with greater age at death in dogs and cows. Animals with cleaved-cell lymphomas were older at death than those with noncleaved tumors; this difference was highly significant in cows. The number of metastases was greater with nodular tumors in all three species, and was equal in cleaved and noncleaved tumors. The biological behaviour of lymphoid tumors in animals is similar to those in man when the same criteria of classification are used.

Age Factors↗
PubMed1981

Partial purification of a common antigen in bovine lymphoma and its use in a lymphocyte blastogenesis assay.

An antigen was isolated from tumor cells derived from cases of bovine lymphoma which caused the in vitro blastogenesis of lymphocytes from nine of 13 (69%) adult cattle with lymphoma. Lymphocytes derived from five of 122 (4%) normal adult cattle also underwent blastogenesis while lymphocytes from three cases of the sporadic form of lymphoma did not respond. Blastogenesis of lymphocytes from normal cattle may have resulted from alloantigen activity in the antigen; however, normal lymph node antigen did not stimulate lymphocytes from normal adult cows or cows with lymphoma. Antigen derived from tumor was localized to the cell membrane and cytoplasm of tumor cells by indirect immunofluorescent staining using an antiserum prepared in rabbits. Specific fluorescence was reduced by the absorption of this antiserum with a crude tumor extract. The antiserum did not cross-react with normal lymph node antigen or viral components as demonstrated by immunodiffusion. With further refinement of the antigen, the blastogenesis assay may be of use in the early detection and study of the pathogenesis of lymphoma in adult cattle.

Animals↗
PubMed1981

Response of cows with lymphoma to the intradermal injection of tumor cell antigens and phytohemagglutinin.

Tumor cell-membrane antigens did not elicit specific intradermal reactions in cows with lymphoma and were therefore not effective in identifying animals with tumor. Sixty-two percent (8/13) of cows with lymphoma in the advanced stages of disease responded poorly to the intradermal injection of a nonspecific mitogen (PHA-M) and normal lymphoid cell extracts. This finding may explain the lack of response to the tumor cell extracts that some cows with lymphoma and indicates the presence of immune deficits in animals with lymphoma. Six of eight animals with tumor and poor cutaneous sensitivity had sera that inhibited the blastogenesis of normal lymphocytes. The presence of this inhibitory material is associated with the presence of tumor, not with bovine leukemia virus infection and partially accounts for the relative cutaneous anergy in cattle with lymphoma.

Animals↗
PubMed1981

Failure to detect soluble tumor associated antigen by radioimmunoassay in bovine lymphoma.

The detection of circulating soluble tumor-associated antigen by radioimmunoassay was attempted in cows with lymphoma. The assay system did detect PAGE-purified tumor-associated antigen but did not detect immunoreactive substances in the sera of 20 affected animals and 20 normal cattle. Similarly, ultrafiltration of low pH-dissociated serum to separate immune complexes did not aid in the detection of antigen.

Animals↗
PubMed1981

Cutaneous response to PHA-M and hematological changes in corticosteroid treated cows.

The effect of corticosteroids on the reaction to the intradermal injection of phytohemagglutinin was examined in normal cattle. The associated hematological changes were also examined. Normal, untreated cattle responded to an injection of 1 mg phytohemagglutinin in 0.1 mL saline by a 40 to 80% increase in double skin thickness while corticosteroid treated animals had responses approximately one half of the controls. Neutrophils predominated early in the reaction but were replaced by increasing proportions of lymphoid cells towards 72 hours. These results indicate that an intact and functional inflammatory mechanism is required for a cutaneous response to phytohemagglutinin. Normal animals had a physiological leukocytosis characterized by an increase in mature neutrophils and lymphocytes. Corticosteroid treated animals had a mature neutrophilia, lymphopenia, eosinopenia and monocytosis. These hematological changes were qualitatively similar to those seen in other species.

Adrenal Cortex Hormones↗
PubMed1980

Elemental content of predigested liquid protein products.

Eight commercially available partially digested gelatin liquid products that have been used as a source of protein in dietary regimens for weight reduction and for protein supplementation were analyzed for their elemental composition. These products were prepared either by dry ashing or wet digestion techniques that were suitable for the analysis of individual elements by their respective analytical methods. Analytical methods used to assess the elemental content included inductively coupled argon plasma emission spectrometry for Ca, Mg, P, Fe, Zn, Cu, Mn, Ni, Mo, V, Be, Co, Cr, Tl, Al, Te, Sn and Sb; atomic absorption spectrophotometry for Na and K; hybride generation with atomic absorption spectrophotometry for Se and As; anodic stripping voltammetry for Cd and Pb; and ion selective electrode for F. The content of almost all of the elements in these products was extremely low compared with the amounts supplied daily for normal individuals by usual sources of dietary protein, the adult United States Recommended Daily Allowances, and typical intakes from the Total Diet Study. The following elements were not detectable in significant amounts in these products by inductively coupled argon plasma emission spectrometry: Mo, V, Be, Co, Cr, Tl, Al, Te, Sn, and Sb. The results suggest that use of these predigested liquid protein products as a sole source of nutriment will result in an inadequate intake of all of the essential elements. These products contained insignificant amounts of Ce and Pb, nonessential toxic elements.

Adult↗
PubMed1980

Effects of vitamin C and iron and cadmium metabolism.

Toxic levels of dietary cadmium (5-200 ppm) interfered with iron absorption and produced an iron deficiency. Supplements of iron (particularly the divalent form) and ascorbic acid protected against the cadmium. With very low levels of dietary cadmium (about 0.06-0.08 ppm), typical of those in the diets of humans, supplements of iron(II) and ascorbic acid markedly decreased cadmium concentrations in the liver, kidney, and small intestine. Iron deficiency changed the distribution of cadmium within the body. The effect of ascorbic acid on cadmium metabolism appears to depend primarily, if not entirely, on its influence in improving iron absorption. Maintenance of modest iron stores appears to be very important in minimizing cadmium absorption.

Animals↗