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Biomedical subjects

V E Valli

Publications and source records attributed to V E Valli.

At least 163 records · Page 9Linked to original sources
PubMed1980

The quantitation of Trypanosoma congolense in calves. II. Biochemical changes.

Changes in serum electrolytes, osmolality, total proteins and protein fractions, lipid levels and organ function tests were determined in neonatal and 6-month-old calves infected with T. congolense TREU 112 and control calves. There were no consistent changes in electrolytes or osmolality for either age group of calves. There was a decrease in total serum protein in the infected 6-month-old calves, caused by decreases in the albumin and beta 2-globulin fractions. The total serum protein level remained constant in the infected neonatal calves, but there was a significant decrease in the albumin fraction which was compensated for by an increase in alpha-globulin and gamma-globulin fractions. Total serum lipids and cholesterol were decreased and triglyceride levels and erythrocyte phospholipid levels were significantly elevated in both age groups of infected calves. Tests of adrenal and hepatic function were not significantly different in infected calves compared to control calves of the same age group. Thyroid function tests showed that T3 was significantly elevated in infected 6-month-old calves, whereas T4 was significantly decreased in infected neonatal calves.

Adrenal Glands↗
PubMed1980

The quantitation of trypanosoma congolense in calves. III. A quantitative comparison of trypanosomes in jugular vein and microvasculature and tests of dispersing agents.

Hemocytometer and cytofluorometric methods were used to count trypanosomes in the blood of neonatal and six-month-old calves infected with T. congolense. The correlation between these methods was highest in the six-month-old calves because their parasitemia was greater and the accuracy of cytofluorometric counting is reduced below 1,000 trypanosomes per microliter of blood. Fine needle aspiration biopsies showed many trypanosomes marginated in cerebral cortical capillaries, but few in muscle or liver. Quantitatively, the cerebral capillaries in the infected six-month-old calves were significantly wider than their controls with fewer endothelial nuclei suggesting capillary dilatation. There were fewer trypanosomes and no significant changes in capillary width in the neonatal calves. Several drugs were tried for activity in dispersing marginated trypanosomes into axial flow. Berenil and dexamethasone had a significant effect on trypanosome counts in blood and tissue whereas, epinephrine caused a fleeting increase in parasitemia. Hetastarch, dextran and cyclophosphamide had no specific effect. Fine needle aspiration bipsies of brain, thirty minutes after Berenil injection showed that the capillaries were cleared of trypanosomes.

Animals↗
PubMed1979

The pathogenesis of Trypanosoma congolense infection in calves. III. Neutropenia and myeloid response.

Calves infected with Trypanosoma congolense TREU 112 had, at the onset of anemia, a very low total white cell count and neutropenia but with chronicity there was lymphocytosis. Infected calves had a marked reduction in granulocyte mobilization for the first 14 weeks of infection and there was reduced ability to mount an inflammatory response during the onset of anemia. Bone marrow aspiration biopsies showed marked erythroid hyperplasia in response to the anemia with a relative and likely absolute reduction in myeloid precursors and marrow granulocyte reserves.

Agranulocytosis↗
PubMed1979

The pathogenesis of Trypanosoma congolense infection in calves. IV. The kinetics of blood coagulation.

Blood coagulation studies showed there was a pronounced thrombocytopenia and hypofibrinogenemia in Holstein calves infected with Trypanosoma congolense TREU 112. There was also ineffective thrombopoiesis characterized by an increased megakaryocytic mass, reduced uptake of 35S-methionine into peripheral blood platelets and a normal platelet lifespan. There was an increased uptake of isotopic label into fibrinogen and a shortened half life indicating a consumptive error with increased peripheral use of fibrinogen. No consistent abnormalities were found in ethanol gelation, partial thromboplastin time, clot retraction and lysis or plasminogen assay. Fibrin split products were rarely detected. These findings suggest that in the chronic form of bovine trypanosomiasis there is a partially compensated consumption coagulopathy.

Animals↗
PubMed1979

The pathogenesis of Trypanosoma congolense infection in calves. V. Quantitative histological changes.

Calves infected with Trypanosoma congolense TREU 112 had generalized microvascular dilation which was most prominent in the liver and the mesentery; there also was increase in cellularity in the lung with significant alveolar thickening and accumulation of hemosiderin-bearing cells in the alveolar septa, focal accumulations of lymphocytes primarily at the corticomedullary junction of the kidneys and a well developed glomerulonephritis, likely membranoproliferative. Reticuloendothelial changes were marrow hyperplasia with an erythroid shift, moderate hemosiderosis and moderate dysthrombopoiesis, marked thymic cortical atrophy, hypersplenism and enlarged nodes with reduced cellular density, paracortical atrophy and medullary sclerosis.

Abomasum↗
PubMed1979

Bovine granulocyte/macrophage and erythroid colony culture: characteristics of the colonies and the assay systems.

Bovine bone marrow granulocyte/macrophage colonies were cultured in vitro in methyl cellulose and in plasma clots using bovine endotoxin-stimulated serum as a source of colony stimulating activity. The endotoxin-stimulated serum was four times as potent as the control serum in the methyl cellulose cultures. No significant increase in the number of colony forming units was observed when bovine marrow cells were maintained in suspension cultures for various periods prior to plating in methyl cellulose. The percentage of glass/plastic adherent cells in bovine marrow cells was observed to be 43% +/- 12 (SD). Benzidine positive erythroid colonies appeared in plasma clot cultures on day 4 and disappeared by day 9. No second population of erythroid colonies appeared either as a function of time or as a function of erythropoietin concentration. The optimum erythropoietin concentration for bovine erythroid cultures was found to be 1.0 unit/mL. A significant difference was observed between animals in their marrow capacity to produce erythroid colonies in culture but no significant difference was observed within individual animals over a period of three months.

Animals↗
PubMed1979

Inhibition of bovine bone marrow granulocyte/macrophage colony formation in vitro by serum collected from cattle infected with Trypanosoma vivax or Trypanosoma congolense.

Serum collected from cattle infected with Trypanosoma vivax or Trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in methyl cellulose cultures. Maximum inhibition was caused by serum collected two and three weeks post infection. The degree of inhibition appeared to be related to the degree of parasitemia. Inhibition of erythroid colony formation by serum collected from these animals was not observed.

Animals↗
PubMed1979

Cyclical changes of vaginal cytology in the cat.

Vaginal smears from seven cats were examined at two-day intervals for 32 days in order to describe the cyclical pattern of epithelial cells exfoliated throughout the stages of the estrus cycle. Vaginal epithelial cells were classified as parabasal, intermediate and superficial (nucleate and anucleate) cells, and their dimensions were measured for the purpose of definition. The percentages of the epithelial cell populations (i.e. Maturation Index) from Wright's stained smears, were determined at all stages of the estrus cycle. The Eosinophilic Index was estimated on Papanicolaou stained smears. Smears of cats in estrus were populated almost entirely with nucleate and anucleate superficial epithelial cells. Proestrus was characterized by intermediate epithelial cells with increasing eosinophilia, and rare neutrophils. Metestrus was associated with desquamation of intermediate and parabasal epithelial cells, neutrophils and debris. In the anestrus period, groups of intermediate cells and some parabasal epithelial cells were exfoliated. Two cats in the study did not cycle and exhibited anestrus. Of the five cats cycling, eight estrus periods were observed of two to five days duration. The cycles were of 15 to 17 days interval in three normal cats. Two cats did not show a second estrus within 30 days, and were subsequently found to have bacterial growth on the culture of vaginal swabs, however the presence of an initial ovular estrus cannot be ruled out. The rare presence of erythrocytes was associated with vaginal bacterial infections and discharge in two cats.

Animals↗
PubMed1978

Nutritional and metabolic studies of distillable fractions from fresh and thermally oxidized corn oil and olive oil.

A semisynthetic diet containing 15% by weight of dietary fat was fed to six groups of male wistar rats for 28 days. Two groups received the distillable fraction of fresh corn oil (DCO) or fresh olive oil (DOO), two groups the distallable fractions of the thermally oxidized fats (OCO,OOO), and two groups received the respective fresh fats as controls (FCO, FOO). Substantial changes in the fatty acid composition occurred in the fats upon thermal oxidation. Only the rats that received OOO showed overt symptoms of heated fat toxicity. This was reflected in the histological scores of these animals with the liver sustaining the most numerous and severe lesions. Tissue fatty acid changes of any significance were confined largely to the polar liver lipid of the rats that were fed OCO or OOO. The results of this study would suggest that the relatively greater toxicity of OOO, compared to OCO, may in part be due to the high oleic:linoleic acid ratio of the fresh olive oil and in part to a higher tocopherol content of the corn oil.

Adipose Tissue↗
PubMed1978

The pathogenesis of Trypanosoma congolense infection in calves. I. Clinical observations and gross pathological changes.

Holstein calves infected with Trypanosoma congolense TREU 112 had intermittent fever, debility and a poor hair coat. At postmortem examination the most significant findings were enlargement of the liver, kidneys and spleen and increased volume of hematopoietic marrow. A group of 13 calves infected for 18 weeks had marked enlargement of lymph nodes throughout the body and hemal nodes were prominent in the sublumbar area caudal to the kidneys. Another group infected for 7 weeks had no increase in the weight of lymph nodes. Studies with 51Cr labelled autologous red cells given shortly before postmortem examination showed that the liver was the most active organ with respect to sequestration of labelled red cells.

Animals↗
PubMed1978

The pathogenesis of Trypanosoma congolense infection in calves. II. Anemia and erythroid response.

The anemia caused by Trypanosoma conogolense TREU 112 in Holstein calves was of moderate severity and normochromic, macrocytic in the acute phase changing to normochromic, normocytic with chronicity. The anemia was hemolytic and responsive as shown by sharply decreased myeloid:erythroid ratio and increased mean corpuscular volume. 51Cr red cell labelling studies showed that red cell lifespan was halved in the acute phase and there was an increase in plasma volume. Surface organ counting of liver showed it to be the major site of red cell destruction. The anemia was partly dilutional as a result of the increased plasma volume and primarily hemolytic likely of a non-specific immune (innocent bystander) pathogenesis.

Anemia↗
PubMed1978

Bovine erythrocytic, granulocytic and macrophage colony formation in culture. A preliminary report.

Bovine erythrocytic colonies containing up to 300 cells each were produced by using a plasma clot technique with five percent CO2 at 37 degrees C. with high humidity and 2.5 units of sheep step III erythropoietin per milliliter. Erythropoietin was essential for colony formation. The number of colonies ranged from 24 to 823 per 10(5) nucleated marrow cells plated, in different animals. Some of the erythroid colonies were mixed with granulocytes. Granulocyte/macrophage colonies were produced in methyl cellulose cultures. Colonies contained up to 1000 cells and the number of colonies ranged from 13 to 981 per 10(5) nucleated marrow cells plated, from different animals. Glass adherent cells appeared to produce colony stimulating activity in culture. In both culture systems, there was a direct linear relationship between the number of nucleated marrow cells plated and the number of colonies produced.

Animals↗
PubMed1978

A cytofluorometric method of counting trypanosomes.

A rapid automated method of counting trypanosomes was developed using cytofluorometric methods. Organisms were vitally stained with acridine orange, and DEAE cellulose separated T. congolese were accurately counted at all concentrations. T. congolense in heparinized whole bovine blood were also counted accurately at levels greater than 1,000 per microliter. At lower levels, small fluorescent particles in whole blood interfered with the counts.

Animals↗