Nelore females along a new Brazilian agricultural frontier: hematological and clinical-biochemical approaches / [Abordagens hematológicas e bioquímicas clínicas de fêmeas Nelore na nova fronteira agrícola brasileira]

The Nelore breed is the second largest bovine breed in the world and has actively participated in the expansion of new Brazilian agricultural frontiers. In this context, the purpose of this study was to determine the hematological and biochemical reference intervals of healthy Nelore matrices raised under an extensive regime without supplementation along southwest of Piauí state. Blood samples were collected from fifty-five multiparous female of the Nelore breed. Biochemical and hematological parameters were analyzed using a parametric statistical method with 95% CI of reference limits. The average values of red blood cells, hemoglobin as well as hematimetric indices showed reference ranges similar to reference standards. The hematocrit as well as granulocytes and agranulocytes presented alterations typical of animals raised in environments with higher temperatures. Mineral, enzymatic, protein and metabolic profiles were similar to other bovine breeds but with a narrower range of values. However, lower mean values were observed for levels of ionized calcium, total protein and urea. Nelore females present slightly different biochemical and hematological profiles from other breeds, which might result from the environmental and nutritional management applied and the natural deficiency of nitrogen, phosphorus and calcium in the region's pastures.(AU)

Nelore é a segunda maior raça bovina do mundo e tem participado ativamente da expansão das novas fronteiras agrícolas brasileiras. Nesse contexto, o objetivo do presente estudo foi determinar os intervalos de referência hematológicos e bioquímicos de matrizes Nelore criadas em regime extensivo sem suplementação, ao longo do sudoeste do estado do Piauí. Amostras de sangue foram coletadas de 55 fêmeas multíparas da raça Nelore. Os parâmetros bioquímicos e hematológicos foram analisados por método estatístico paramétrico com IC 95% para os limites de referência. Os valores médios de hemácias, hemoglobina e índices hematimétricos apresentaram intervalos de referência semelhantes aos padrões de referência. Tanto o hematócrito quanto os granulócitos e os agranulócitos apresentaram alterações típicas de animais criados em ambientes com temperaturas mais elevadas. Os perfis mineral, enzimático, proteico e metabólico foram semelhantes aos de outras raças bovinas, mas com uma faixa de valores mais estreita. No entanto, valores médios mais baixos foram observados para os níveis de cálcio ionizado, proteína total e ureia. Fêmeas Nelore apresentam perfis bioquímicos e hematológicos ligeiramente diferentes de outras raças, o que pode resultar dos manejos ambiental e nutricional aplicados e da deficiência natural de nitrogênio, fósforo e cálcio nas pastagens da região.(AU)

Granulocytopenia associated with thymoma in a domestic shorthaired cat.

A 5-year-old, spayed female cat was referred because of a mass in the cranial mediastinum noted on thoracic radiographs. A thymoma was diagnosed following ultrasound and biopsy of the mass. Treatment was initiated with coarse-fraction radiation therapy using external-beam therapy (four fractions of 5 Gy). The mass responded, but granulocytopenia developed. Bone marrow examination showed a myeloid to erythroid ratio of approximately 1:1, with a left shift within the myeloid line. These findings, as well as the lack of toxic changes within the peripheral blood neutrophils, suggested immune-mediated destruction of peripheral granulocytes. Immune suppression with prednisone and cyclosporine was instituted. After 7 weeks, the neutrophil count returned to normal. The tumor was removed, and cyclosporine was reduced and eventually discontinued 3 weeks postsurgery.

Toxic effects of mebendazole at high dose on the haematology of red-legged pademelons (Thylogale stigmatica).

OBJECTIVE: To investigate the effects of mebendazole at high dose on the haematology of macropods. Experimental. PROCEDURE: Five red-legged pademelons (Thylogale stigmatica) were dosed orally with mebendazole at 50 mg/kg/d for 5 to 6 days. Two control pademelons were dosed with water. Regular blood samples were taken for haematology over 20 days. RESULTS: All four treated pademelons sampled at 5 days developed severe leucopenia and neutropenia, moderate lymphopenia, thrombocytopenia, eosinopenia and monocytopenia, as well as bone marrow aplasia within 5 to 11 days after the first mebendazole dose. Four pademelons died unexpectedly or became ill and were euthanased 5 to 11 days after the first dose while the other animal recovered after 5 days of illness. Necropsy revealed systemic infection with opportunistic enteric bacteria, non-suppurative inflammation in tissues, haemorrhage and ulceration of the gastrointestinal tract. CONCLUSIONS: Red-legged pademelons rapidly develop bone-marrow aplasia and subsequent septicaemia after administration of high doses of mebendazole. Mebendazole at high doses should not be used for macropods.

The effect of 5-fluorouracil treatment of chicks: a cell depletion model for the study of avian polymorphonuclear leukocytes and natural host defenses.

Two-week-old Leghorn chicks injected intravenously with 5-fluorouracil (5-FU) were found to have a three- to fivefold reduction (P < .05) in circulating polymorphonuclear leukocytes (PMN) 5 to 10 days later. The reduction in PMN was dose-dependent with a dosage of 200 mg/kg body weight of 5-FU, causing suppression of PMN to almost undetectable levels. Increasing the dosage of 5-FU to 400 mg/kg had no further effect on reducing the number of PMN in the circulation nor were overt clinical signs of toxicity observed. Single per os administration of 10(6) viable Salmonella enteritidis (SE) to individual groups of chicks treated or not treated with 5-FU at 2, 4, 6, 8, 10, or 12 days postinjection resulted in a two- to sixfold increase in the incidence of SE organ invasion (liver and spleen) beginning on Day 4 postinjection and continuing through Day 12 postinjection. The greatest increase in organ invasion occurred on Days 8 through 10 postinjection and was inversely proportional to the greatest reduction in the number of circulating PMN. Using 5-FU, a granulocytopenic chicken model was developed that can be used to study the defensive role of avian heterophils against infectious agents. The results from these preliminary experiments indicate that PMN play a significant role in reducing organ invasion by SE in Leghorn chicks.

Methods for detection of immune-mediated neutropenia in horses, using antineutrophil serum of rabbit origin.

Equine neutrophil antibody was raised in rabbits inoculated with equine neutrophils isolated to purity greater than 99.0%, using Percoll density-gradient sedimentation. Neutrophil antibody was detected by use of agar gel diffusion, leukoagglutination, indirect immunofluorescence, staphylococcal protein A and streptococcal protein G binding, and phagocytic inhibition techniques. Precipitin lines and leukoagglutination were seen in antiserum dilutions of 1:4 and 1:64, respectively. The specific nature of leukoagglutination was characterized by the formation of rosette-like clumps of neutrophils. Specific bright membranous fluorescence was seen in neutrophils treated with the antiserum and exposed to fluorescein-conjugated goat anti-rabbit immunoglobulin, and staphylococcal protein A and streptococcal protein G. Whereas the indirect immunofluorescence and protein G-binding tests were equally sensitive and resulted in titer of 1:256, the protein A-binding test was less sensitive and resulted in titer of only 1:32. Nonspecific binding of protein A and protein G was noticed as uniform or patchy cellular fluorescence in a small number of neutrophils. Treatment of neutrophils with antiserum up to dilution of 1:8 resulted in a significant (P less than 0.05) suppression of phagocytosis of opsonized zymosan particles. Thus, protein G-binding and indirect immunofluorescence tests are highly sensitive to detect neutrophil antibody and may be used to diagnose immune-mediated neutropenias in horses and, possibly, in other animal species.

Pulmonary lesions induced by Pasteurella haemolytica in neutrophil sufficient and neutrophil deficient calves.

The role of neutrophils in the development of peracute lung lesions of bovine pneumonic pasteurellosis was investigated. Eight calves were divided into two groups of four calves each. Group I was treated with intravenous phosphate-buffered saline and served as the neutrophil sufficient calves. Group II was treated with intravenous hydroxyurea which produced a state of neutropenia. When peripheral blood neutrophil numbers dropped below 300 cells/microL in group II, all calves were challenged with an intrabronchial bolus of Pasteurella haemolytica in the log phase of growth. An acute inflammatory process occurred in both groups of calves indicated by a rise in body temperature. While pulmonary lesions occurred in both groups by six hours postinoculation, they varied in pathological characteristics. Pulmonary lesions in the neutrophil sufficient calves consisted of fibrinopurulent alveolitis-bronchiolitis with associated alveolar septal necrosis, interlobular edema, and intravascular thrombi. The neutrophil deficient calves had extensive intra-alveolar edema, interlobular edema, intraalveolar hemorrhage, atelectasis, and focal areas of alveolar septal necrosis. These results show that P. haemolytica can induce severe pulmonary tissue damage through both neutrophil dependent and neutrophil independent mechanisms.

Chronic idiopathic neutropenia in a cat.

Persistent neutropenia (0-0.6 X 10(9) neutrophils/l) was documented during a 10-month period in a 4-year-old spayed female domestic shorthair cat that was presented for anorexia and depression. Salient abnormalities detected on physical examination were fever (40.3 degrees C), dehydration, and gingivitis. The cat was neutropenic (0.5 X 10(9) neutrophils/l) and enzyme-linked immunosorbent assay (ELISA) test for feline leukemia virus was negative. A bone marrow aspirate showed decreased numbers of mature granulocytic cells. In vitro bone marrow cultures for colony-forming units-granulocyte/macrophage (CFU-GM) were performed comparing bone marrow from the patient with that of a normal cat. The patient had fewer CFU-GM than the control. The number of CFU-GM increased when bone marrow mononuclear cells were cultured in the presence of 10(-5) and 10(-6) mol/l of hydrocortisone, but the cat did not respond to oral prednisolone therapy. The pathogenesis of the neutropenia in this cat remains obscure, but resembles the chronic idiopathic neutropenia syndrome of man.

Bone marrow response in cattle with chronic dermatitis caused by Psoroptes ovis.

Six Hereford heifer calves were infested with Psoroptes ovis and compared to six uninfested control calves. Infested calves developed severe exudative dermatitis which covered 100% of the body surface by 7 weeks after infestation. They developed moderate nonregenerative anemia, decreased numbers of neutrophils and lymphocytes, and increased plasma protein and fibrinogen concentrations. Sternal marrow core biopsies taken 7 weeks after infestation were 75 to 90% cellular, while cores from uninfested calves were 10 to 20% cellular. Comparison of myelograms between the two groups of calves revealed increased M:E ratio, myelocyte and metamyelocyte hyperplasia with depletion of mature neutrophils and eosinophils in the P. ovis-infested calves. It was concluded that P. ovis-infested calves develop myeloid hyperplasia and that mange-related neutropenia is not due to bone marrow suppression by a mite or scab-associated toxin.

Cyclic hematopoiesis associated with feline leukemia virus infection in two cats.

Cyclic oscillations in the numbers of blood elements were detected in 2 cats with FeLV infection. Periodic neutropenia, followed by a return to normal neutrophil numbers, was detected in both cats. The mean cycle duration was 11.8 days, with a range of 8 to 14 days. Just before the return of normal neutrophil numbers, monocytosis developed. In 1 cat, cyclic variations in the number of reticulocytes and platelets also were detected. Bone marrow aspirates obtained during periods of neutropenia had a predominance of progranulocytes in the myeloid cell line. myeloid hyperplasia, with numerous segmented neutrophils, was seen in bone marrow aspirates obtained during periods of normal neutrophil numbers. Oral administration of prednisolone resulted in cessation of the cyclic oscillations of blood elements in 1 cat. Cyclic hematopoiesis appeared to be another non-neoplastic manifestation of FeLV infection.

Neutropenia in cats with the Chediak-Higashi syndrome.

Thirteen cats with Chediak-Higashi syndrome and 22 control cats from the same colony, were evaluated for neutropenia. The absolute neutrophil counts of the Chediak-Higashi syndrome cats were significantly less (P less than 0.05) than those of the control cats. It is concluded that Chediak-Higashi syndrome cats, like Chediak-Higashi syndrome humans, have a neutropenia associated with the other manifestations of the syndrome. Lysozyme activity which was undetectable in the serum of both Chediak-Higashi syndrome and control cats was not of use for determining if the neutropenia was the result of neutrophil destruction.

Canine cyclic hematopoiesis: alterations in T lymphocyte subpopulations in peripheral blood, lymph nodes, and thymus of gray collie dogs.

Cyclic hematopoiesis (CH), also called cyclic neutropenia, is an inherited disorder known to occur in both humans and gray collie dogs. Previous reports have provided ample evidence to suggest that lymphocyte activity and regulatory mechanisms may be abnormal in CH. The present study examined the lymphocyte populations of several lymphoid compartments of gray collie dogs. The percentage of B lymphocytes in the lymph nodes of CH dogs was significantly increased whereas that of null lymphocytes was decreased. The percentage of T lymphocytes did not differ between CH and normal dogs, however, the proportions of T lymphocyte subpopulations were significantly different. The levels of T lymphocytes expressing IgGFc receptors (T gamma) in the thymus, lymph nodes, and peripheral blood were significantly increased; whereas the levels of T lymphocytes expressing IgMFc receptors (T mu) were significantly decreased. The percentage and absolute numbers of T gamma and T mu lymphocytes cycled in CH dogs. The percentage and absolute numbers of neutrophils were greatest when that of T gamma lymphocytes was reduced. The cycles of monocytes and T gamma lymphocytes occurred in close association and a linear relationship between the levels of these cells was observed both in terms of percentage (r = 0.62; P less than 0.01) and absolute number (r = 0.67; P less than 0.05). The percentage of T gamma and T mu lymphocytes were inversely correlated (r = -0.68; P less than 0.01).

Neutrophil depletion of calves with hydroxyurea: methods and clinical and pathologic effects.

Twenty-six Holstein calves were treated with hydroxyurea in order to induce neutropenia. Calves were given a daily dosage of hydroxyurea (70 mg/kg of body weight) for 4 consecutive days, and clinical signs, blood leukograms, hemograms, and platelet counts were monitored daily until the calves became neutropenic. Once a neutropenic state was induced, the calves were anesthetized and pulmonary function tests were performed. Subsequently, calves were euthanatized and complete necropsies were performed. Hydroxyurea treatment induced profound neutropenia in all calves by 8 days after initiating treatment, with mild decreases in circulating numbers of lymphocytes. Treatment did not cause clinical or pulmonary functional abnormalities. Severe pathologic changes were restricted to the bone marrow and consisted of partial to complete destruction of myeloid elements, with less severe effects on erythrocytic precursors and megakaryocytes. Hydroxyurea was useful for the induction of neutropenic states in calves and did not induce major toxic effects on other cells when given at 70 mg/kg.

Granulocytopaenia and thrombocytopaenia in dairy cattle--a suspected mycotoxicosis.

During a 6-week period, 22 Dairy Shorthorn cows and heifers died with granulocytopaenia and thrombocytopaenia. Clinical signs observed in the affected animals included increased salivation, pyrexia, depression, rumenal stasis, bilateral epistaxis, melaena, increased bleeding after removal of retained foetal membranes and rapid weight loss. Despite intensive antibiotic and vitamin K therapy and blood transfusions, all affected animals died. The aetiological agent, thought to be a fungal toxin, could not be isolated from post mortem specimens or pasture samples.

Development and clinical application of methods for detection of antineutrophil antibody in serum of the cat.

Two techniques, leukoagglutination and indirect immunofluorescence, were adapted to test for the presence of antineutrophil antibody in cat serum. The leukoagglutination test was analogous to an indirect Coombs' test. The test was performed on freshly isolated cat blood neutrophils, with the test results read from stained smears (Wright's stain) made from sedimented antiserum-treated neutrophils. A positive test response was indicated by agglutinated neutrophils on the stained smear. The indirect immunofluorescence test was performed by incubating paraformaldehyde-fixed cat blood neutrophils with test serum, after which the neutrophils were stained with fluorescein isothiocyanate-tagged antiglobulin. A positive test response was a ring of fluorescence surrounding the cells, as viewed through a UV microscope. Serum samples (n = 55) from clinically neutropenic cats were tested for the presence of antineutrophil antibody by the indirect immunofluorescence technique. Ten positive-control sera (rabbit anti-cat neutrophil serum) and 10 negative-control sera (normal cat serum) were included. Only the positive control sera exhibited neutrophil fluorescence, indicative of antineutrophil antibody. None of the 55 samples of clinical origin showed any appreciable fluorescence.

Effects of heterologous antineutrophil antibody in the cat.

Rabbit anti-cat neutrophil serum was injected intraperitoneally into cats to study its effects on blood neutrophil numbers, on development of neutrophils in bone marrow, and on the fate of circulating and developing neutrophils. There was a significant difference (P less than 0.05) in curves of blood neutrophil numbers between antineutrophil serum (ANS)- and normal rabbit serum (NRS)-injected cats; neutrophil counts tended to decrease in ANS-injected cats, whereas a transient increase in counts occurred in NRS-injected cats. Significant left shifts (P less than 0.05) were present in ANS-injected cats, but absent in NRS-injected cats. Toxic morphologic changes were noted in blood neutrophils in all ANS-injected cats. Significant bone marrow changes (P less than 0.05) occurred in ANS-injected cats, but were absent in NRS-injected cats. Myelocyte percentages of the granulocyte marrow population increased during the time that segmented neutrophil percentages decreased. In ANS-injected cats, the percentage of cells in the mitotic pool (myeloblasts, promyelocytes, myelocytes) significantly increased (P less than 0.05), with a corresponding significant decrease (P less than 0.05) in the postmitotic pool (metamyelocytes, bands, segmented neutrophils). Aspirated bone marrow smears (Wright's stain) revealed marrow macrophages containing phagocytized neutrophil bands and segmented neutrophils. Sections of liver obtained after cats were necropsied revealed neutrophil phagocytosis by Kupffer's cells, but neutrophil phagocytosis was not demonstrated in other tissues examined.

Effects of poly I:C in porcine iron deficient neutropenia.

Withholding iron dextran treatment normally given to pigs at 1-3 days of age to prevent anemia resulted also in neutropenia. Polyinosinic acid:polycytidylic acid (poly I:C) at 0.5 mg/kg IV at 25 days of age resulted in induction of putative interferon 2 to 24 hours later, with significantly (P less than 0.05) lower concentrations in iron-deficient (Fe-) female pigs than in iron-supplemented (Fe+) female pigs. Poly I:C caused several transient toxic manifestations, including elevations in blood urea nitrogen, creatinine, aspartate aminotransferase, potassium (K), total bilirubin and phosphorus (P), marked leukopenia (both neutropenia and lymphopenia), and declines in serum albumin, calcium, cholesterol, glucose and globulin. Certain blood chemistries before poly I:C were significantly (P less than or equal to 0.05) different: albumin, globulin, cholesterol and K were higher in females than in males; albumin, globulin, glucose, P and K were higher in Fe- than in Fe+ pigs; and total carbon dioxide was higher in Fe+ than in Fe- pigs.