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Biomedical subjects

V E Valli

Publications and source records attributed to V E Valli.

At least 145 records · Page 8Linked to original sources
PubMed1981

Reversibility of the toxicological changes induced by photomirex and mirex.

Photomirex (8-monohydromirex) is a known environmental contaminant. In a previous 28-day and 90-day study, photomirex was shown to cause a number of biochemical and histological alterations in male rats. The present study was undertaken to determine the reversibility of those changes and to compare both effects and reversibility with the present compound mirex. Male rats were fed diets containing 0, 0.05, 0.5, 5.0 and 50 ppm photomirex and 5 ppm or 50 ppm mirex for 28 days. Ten animals/group were killed at this time and the remainder placed on clean feed. Ten animals/group were killed after another 12, 24, and 48 weeks. The lower body weight gain in animals fed 50 ppm photomirex and 50 ppm mirex observed after 28 days on the test was not evidence after 12 weeks on the clean diet or thereafter. Reduced food consumption produced by these groups persisted for 12 weeks but not 24 weeks. Liver hypertrophy was observed in the 5.0-ppm and 50-ppm photomirex groups after 28 days and persisted in the highest dose group for 24 weeks on clean diet. Elevated serum sorbitol dehydrogenase activity was observed in the 50-ppm photomirex group and persisted for 12 weeks on clean diet. Histological changes in liver and thyroid were present up to 48 weeks on clean diet, whereas treatment-related testicular changes observed after 28 days were not evident after 12 weeks. Significant residues of photomirex were still evident in all tissues examined up to 48 weeks postexposure in the 50-ppm photomirex group. The data indicate that photomirex and mirex are extremely persistent compounds and can result in a variety of biochemical and histological changes long after exposure has ceased.

Animals↗
PubMed1981

Equine congenital cutaneous papillomatosis: a report of 5 cases.

Four cases of equine congenital cutaneous papillomatosis were found during a review of 555 cutaneous tumours received at the pathology department, Ontario Veterinary College, during a 10-year period. A fifth case received after that period was also included. Two of the tumours were found in Thoroughbreds, one in a Standardbred, one in an Arabian and in one case the breed was not specified. The anatomical locations were the rib cage, head, hind leg and 2 on the forehead.

Animals↗
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

Ultrastructural alterations in the liver of rats fed photomirex (8-monohydromirex).

Alterations in the liver of rats fed photomirex or mirex for 28 d have been studied by electron microscopy. A dose of 0.05 or 0.5 ppm photomirex produced selective ultrastructural damage to the mitochondria of hepatocytes. The parenchymal cells had a proliferation of smooth-surfaced endoplasmic reticulum (SER) with a concomitant depletion of glycogen, a reduction of rough-surfaced endoplasmic reticulum (RER) profiles, an abnormal accumulation of lipid droplets, and pleomorphic nuclei at the 5 ppm photomirex level. In the animals receiving 50 ppm photomirex there were degenerating foci in the organ. There was an increase of electron-dense bodies in the hepatocytes from the 5 ppm mirex group but these cells, in the animals receiving 50 ppm mirex, had SER proliferation and glycogen depletion. It is concluded that photomirex causes more severe ultrastructural changes in the livers of rats than mirex.

Animals↗
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↗
PubMed1980

Short-term study of the combined effects of mirex, photomirex, and kepone with halogenated biphenyls in rats.

The combined effects of polychlorinated biphenyls (PCBs) or a polybrominated biphenyl (PBB) with mirex, kepone, or photomirex were investigated in rats. Groups of 10 animals were fed diets containing the organohalogens alone or in various combinations for 28 d. Body weight gain and food consumption were not affected by any treatment. Liver weight was increased in the group fed Aroclor 1260/photomirex and in all groups receiving PBB. Hepatic microsomal enzyme activities were elevated in the groups treated with halogenated biphenyls alone; this effect was not potentiated in the presence of mirex-related compounds. Serum biochemical parameters were, for the most part, normal. Hematology tests revealed no abnormalities. Histological changes occurred in the liver, thyroid, and kidney of rats treated with the organohalogens alone or in combination. Liver alterations consisted of central lobular cytoplasmic enlargement, exaggerated periportal perinuclear halos, and increased nuclear hyperchromicity and anisokaryosis. Fatty degeneration was observed in all treated groups. Thyroid changes were characterized by a generalized reduction in follicular size and colloid density with collapse of the follicles. Kidneys suffered mild eosinophilic cytoplasmic inclusions in the proximal convoluted tubule and focal lymphoid aggregates. Histological changes due to PCBs and PBB were aggravated by mirex and related compounds. The degree of damage appeared to be additive rather than potentiative. Mirex and photomirex levels in livers of rats concomitantly exposed to halogenated biphenyls were four to six times higher than those in rats fed mirex-related compounds alone. However, the toxic response in this organ was not potentiated as a result of the increased accumulation. It was concluded that mirex-related compounds at the dose levels studied did not potentiate the effects produced by halogenated biphenyls and vice versa.

Animals↗
PubMed1980

An anticoagulant for transport of bovine blood.

Various anticoagulant were assessed in order to develop a transport media for bovine blood which would improve leukocyte stability. The effects of time, disease in the donor and different personnel and laboratory equipment were also tested. The transport media most effective for leukocyte stability was found to be Titriplex IV. This is a modification of Titriplex I by the inclusion of acetylsalicyclic acid to prevent cellular clumping and by the removal of methylene blue. Anticoagulant citrate dextroseformalin-ASA performed equally well for transport but cellular morphology was impaired. Febrile or neoplastic disease in the donor animal did not alter the efficiency of the formalin containing anticoagulants.

Animals↗
PubMed1980

Serum electrophoresis and immunoglobulin concentrations in cows with lymphoma.

Changes in the serum electrophoretic patterns and immunoglobulin (Ig) concentrations were examined in cows with lymphoma, in clinically normal cows, and in cows with various inflammatory conditions. Cows with lymphoma had moderately increased concentrations of alpha 2-globulin which were significantly different from concentrations in normal animals (P less than or equal to 0.01) and in animals with inflammatory conditions (P less than or equal to 0.05). This was possibly due to the increase in acute-phase reactant proteins which occurs with inflammation and neoplasia; however, there was the suggestion that these alpha 2-globulins may be qualitatively different in animals with neoplasia. beta 2-Globulins were significantly (P less than or equal to 0.01) decreased in cows with lymphoma, and this was attributed to lower concentrations of Ig observed in this group. All Ig classes, except IgA, were decreased in cows with lymphoma, but the greatest decrease was observed in the IgM class.

Animals↗
PubMed1980

The quantitation of Trypanosoma congolense in calves. Iv. In vitro culture of myeloid and erythroid marrow cells.

Myeloid and erythroid cultures were prepared from bone marrow aspirates taken from control and T. congolense infected neonatal and six-month-old calves. The aspirates obtained from the infected animals were more cellular than the controls and it was found that the removal of adherent cells prior to Ficoll separation improved the sensitivity of the cultures to colony stimulating factors and removed the background connective tissue cells and megakaryocytes from the resulting colonies. There was an apparent decrease in the number of myeloid colonies from the infected six-month-old calves, but an initial increase in myeloid colonies in the infected neonatal calves compared to their controls. There were no significant differences between infected and control calves for the numbers of erythroid colonies produced, but the degree of maturation as measured by hemoglobinization was decreased in two infected six-month-old calves at week 13 of infection.

Animals↗
PubMed1980

Inhibition of lymphocyte blastogenesis by sera from cows with lymphoma.

The sera from cows with lymphoma inhibit the blastogenesis of normal lymphocytes. The inhibitory sera were partially characterized. Twenty of 34 sera from cows with lymphoma caused inhibition, whereas 3 of 25 sera from healthy animals were inhibitory. Sera from 15 cows with various inflammatory conditions did not cause inhibition. Seventy-four cows were tested for responsiveness to phytohemagglutinin, and of this group, the stimulation indices of 25 animals which had antibody to the bovine leukemia virus did not differ from the remainder of the group. The inhibitory substance: (a) was heat stable at 56 C for 30 minutes, (b) was not overcome by the addition of phytohemagglutinin, (c) was active in a manner that was proportional to the concentration of serum in the culture media, (d) was not lymphocytotoxic at a concentration which was profoundly inhibitory to blastogenesis, (e) was found in the first peak eluted from a Sephadex G-200 column, (f) was nonspecifically active because it inhibited the blastogenesis of a panel of lymphocytes from healthy animals, (g) was present in 59% of cows with lymphoma in the terminal stages of disease, (h) was rarely present in healthy cows or cows with inflammatory conditions, and (i) was not associated with bovine leukemia virus infection in the absence of tumor development.

Animals↗
PubMed1980

The quantitation of Trypanosoma congolense in calves. 1. Hematological changes.

Anemia due to Trypanosoma congolense infection in neonatal and 6-month-old calves was hemolytic and moderately responsive. The red cells were macrocytic and normochromic in both groups of calves and the anemia was milder in infected neonatal calves compared to the 6-month-old calves. The neonatal calves maintained normal white blood cell counts and developed a lymphocytosis at two weeks of infection. The six-month-old calves developed mild neutropenic leukopenia at one week post-infection without lymphocytosis. Plasma iron turnover rates were not different between infected and control calves in either age group at the second week of infection but both groups of infected calves had higher turnover rates at the sixth week of infection. The mean percent of radioiron uptake into peripheral blood red cells was similar in the controls and infected calves, but the rate of appearance of labelled red cells in the peripheral blood was more rapid in the infected calves. Radioiron uptake was depressed in the infected six-month-old calves during second week of infection but not in the sixth week. Apparent plasma volumes were increased in both groups of calves at both time periods.

Anemia, Hemolytic↗
PubMed1980

Inhibition of leukopoiesis by sera from Trypanosoma congolense infected calves: partial characterization of the inhibitory factor.

Sera collected from calves infected with Trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in vitro, but not erythroid colony formation. The inhibitor was found to be TCA precipitable in nature and on Sephadex G-200 chromatography, it was found to elute with the second major peak. Sonicated T. brucei, T. congolense, and T. theileri added directly into the cultures had no effect on granulocyte/macrophage colony formation, but induced significant enhancement of erythroid colony formation.

Animals↗