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Biomedical subjects

R D Schultz

Publications and source records attributed to R D Schultz.

At least 19 recordsLinked to original sources
PubMed1979

Serological response of the bovine fetus to bovine viral diarrhea virus.

Susceptible pregnant heifers were inoculated with bovine viral diarrhea virus at 150 days of gestation and earlier. Fetuses were surgically collected at selected times after inoculation. Serum immunoglobulins were quantitated, and the presence of specific antibodies was determined. In fetuses from heifers inoculated at 150 days, immunoglobulin M (IgM) appeared approximately 2 weeks after inoculation and was followed in 7 days by IgG1. Later IgG2 was detected in the sera of three fetuses. Serum-neutralizing and complement-fixing antibodies were first detected in a fetus taken at 206 days of gestation. Fetuses taken at later times also had specific serum antibodies. Possible explanations for the appearance of serum immunoglobulin substantially before specific bovine viral diarrhea antibodies include the viral alteration of host tissues rendering them antigenic viral activation of polyclonal B cells, and viral modulation of virus-specific lymphocytes causing specific interference with the appearance of antiviral antibodies. In one of the fetuses having IgG2, the serum also contained IgA. Placental leakage of material immunoglobulins was thought to be responsible for the presence of IgA and IgG2 in this fetus. Small quantities of IgM were found in the serum of two fetuses taken from heifers inoculated between 65 and 95 days of gestation, but specific antibodies were found in none.

Animals↗
PubMed1979

Experimental coonhound paralysis: animal model of Guillain-Barré syndrome.

Coonhound paralysis (CHP), a polyradiculoneuritis of dogs that resembles the human Guillain-Barré syndrome, was experimentally reproduced by inoculating a dog with raccoon saliva. The test animal was a coonhound that had previously sustained two naturally occurring attacks of CHP. Success in inducing the disease strengthened the notion that raccoon saliva contains the etiologic factor for CHP and that only specifically susceptible dogs are at risk of developing CHP when exposed to this factor.

Animals↗
PubMed1979

Bovine fetal inoculations with calf rotavirus.

The serological and histopathological responses of bovine fetuses to in utero inoculation with virulent and attenuated strains of the calf rotavirus (reovirus-like agent of neonatal calf diarrhea) are described. Thirteen bovine fetuses, 63 to 190 days of gestation, were inoculated in utero with attenuated (three fetuses) or field strain virus (nine fetuses) or both (one fetus).Serum-neutralizing antibody titers ranging from 1:16 to > 1:256 were detected in six of eight fetuses tested, demonstrating the ability of the bovine fetus to respond immunologically to this agent. The youngest fetus in the series was inoculated at 63 days of gestation and developed a titer of 128 in 64 days. This represents the earliest stage of gestation at which a bovine fetus has been inoculated with a bovine virus and found to produce antibody to it. Serum neutralizing titers in six of the eight dams tested increased significantly following the inoculations of their fetuses in utero. Histological changes associated with viral replication and antigenic stimulation of the lymphoreticular system were observed. Pneumonic lesions consisting of both local and diffuse lymphoreticular proliferation were present in five of the nine fetuses that were alive at slaughter. Gliosis and perivascular cuffing were noted in the brains of two of these fetuses and meningitis was seen in one. No evidence of teratogenic change was found.

Animals↗
PubMed1979

Influence of vitamin E and selenium on immune response mechanisms.

Vitamin E and selenium have both been shown to have immunostimulatory effects in a variety of species when administered in quantities in excess of established deitary requirements. Responses to each nutrient appeared to be independent of the nutrition of the other. Deficiencies of vitamin E and selenium conversely caused suppression of the immune response system, particularly, cell mediated mechanisms. Suppression was shown to be associated with serum factors coating lymphocytes from dogs deficient in vitamin E and selenium. Oral supplementation with vitamin E transformed or removed the suppressive factors, dietary selenium had no effect. In vitro peripheral lymphocyte blast transformation tests corroborated observations of in vivo studies. Reducing agents and synthetic anti-oxidants eliminated suppressive effects in vitro. Suppression was most marked in dogs fed diets highest in polyunsaturated fatty acid (PUFA) content, providing conditions most conductive to lipid peroxidation in vivo. The essential fatty acids linoleic and arachidonic have been shown to similarly influence immunoregulatory mechanisms in vivo. The effect may be a direct one since plasma membrane fluidity of lymphoid cells increases the probability of modification of cell--antigen interactions by PUFA. However, their effect may also be an indirect one. PUFA are known precursor substances of E anf F type prostaglandins which have been shown to affect immediate and delayed hypersensitivity by stimulating synthesis of cyclic AMP. More definitive studies are needed to resolve this question.

Animals↗
PubMed1979

Lymphoreticular neoplasia in a dog resembling malignant histiocytosis (histiocytic medullary reticulosis) in man.

Malignant histiocytosis was diagnosed in a 4-year-old-dog. Major clinicopathologic findings included multiple cutaneous tumors, peripheral lymphadenopathy, hepatomegaly, lytic bone lesions, anemia, thrombocytopenia, and monoclonal IgA gammopathy. Pathologic findings included multi-systemic infiltration of erythrophagocytic malignant histiocytes. Chemotherapy was unsuccessful.

Animals↗
PubMed1978

Immunologic methods for the detection of humoral and cellular immunity.

A variety of immunologic techniques have been introduced during the past few years. Many of these techniques are being applied to clinical specimens in an attempt to help the practicing veterinarian make a diagnosis. The introduction of new techniques requires extensive testing with clinically normal and diseased patients. It is essential for the practicing veterinarian to understand that the techniques available for the detection of immunologic disorders in the dog and cat are not routine diagnostic procedures and that adequate information has not been developed for any of the techniques described to assure the clinical significance of either positive or negative results (Table 3). This should not discourage the practitioner from submitting samples, but should encourage him or her to question the significance of those results and to attempt to correlate them with history and clinical signs before arriving at a final diagnosis.

Agglutination Tests↗
PubMed1978

Nutrition and the immune response.

Vitamin E--selenium deficiency in dogs resulted in complete suppression of lymphocyte responsiveness to stimulation with mitogens. Depressing effects on neutralizing antibody synthesis were also noted. A serum factor associated with the inability of lymphocytes to respond has been isolated and partially purified. The suppressor factor can be removed or transformed by both in vivo and in vitro vitamin E supplementation.

Animal Nutritional Physiological Phenomena↗
PubMed1978

Survival of 59Fe-labeled erythrocytes in cross-transfused equine blood.

Whole blood containing 59Fe-labeled erythrocytes (RBC) and unlabeled serum was transfused from a donor horse on 2 occasions into each of 6 recipient horses. Survival of transfused cells was monitored in the recipients as a function of time after transfusion by measuring RBC radioactivity in the recipients. After the 1st transfusion, RBC concentration of 59Fe remained at 60% to 100% of the transfused dose for 4 days, after which radioactivity values dropped to less than 10% of the dose by 6 days in 3 horses. In the 3 other horses, RBC radioactivity dropped immediately after transfusion, reaching minimal values in approximately 48 hours. After the 2nd transfusion, 1 horse retained 80% of the dose in circulating RBC for 4 days; 2 horses demonstrated a rapid loss of circulating radiolabeled RBC, reaching minimal values in 48 hours; and 2 horses demonstrated minimal radioactivity in the RBC mass even immediately after the transfusion. One horse died of anaphylactic shock during the 2nd transfusion. Erythrocyte compatibility tests, using the direct agglutination test, the antiglobulin test, and the hemolytic test, were not effective in predicting survival of transfused RBC.

Animals↗
PubMed1977

Epidermolysis bullosa simplex in the Collie dog.

Epidermolysis bullosa simplex was diagnosed in 4 Collie dogs. Three of the dogs were less than 6 months old when lesions were first noticed. Lesions were characterized by alopecia, erythema, edema, erythematous plaques, erosions, ulcers, crusts, atrophy, pigmentary changes, and (rarely) blisters affecting the skin over bony prominences and joints of the limbs, face, lips, and ears. Minimal to moderate pruritus or pain was manifested by chewing and licking at the affected areas of the limbs and by pawing and rubbing at the face and ears. Lesions could be induced by frictional trauma in areas of normal skin. Diagnosis was confirmed by histologic examination of affected tissues and induced lesions. Therapy with large oral doses of prednisolone and avoidance of trauma were palliative.

Animals↗
PubMed1976

LDH isoenzymes and myocardial infarction in patients undergoing coronary bypass surgery: an excellent correlation.

To evaluate the efficacy of LDH isoenzymes in the detection of myocardial infarction in patients undergoing coronary bypass surgery, 73 patients were studied pre- and postoperatively by ECG, CPK, SGOT, total serum LDH, and LDH isoenzyme measurements. A reversal of the LDH1:LDH2 ratio was considered indicative of myocardial necrosis. Accordingly, the patients were separated into two groups: Group A (23 patients) who demonstrated an LDH1:LDH2 ratio exceeding 1.0 and Group B (50 patients) who failed to reveal an LDH1;LDH2 reversal. The two groups were similar in regard to preoperative evaluation and operative procedure performed. The postoperative ECG findings were significantly different. In Group A 18 of 23 patients (78 per cent) developed significant new Q waves. This occurred in only one patient in Group B. Significant arrhythmias occurred in 70 per cent of the patients in Group A as compared to 14 per cent of those patients in Group B. Severe congestive heart failure and/or clinical evidence of shock occurred in 39 per cent of Group A patients and in none in Group B. The results of our study indicate that the reversal of the LDH1:LDH2 ratio is a valuable tool for the evaluation of postoperative myocardial infarction.

Aspartate Aminotransferases↗
PubMed1976

Continuous extracorporeal monitoring of animal blood using the glucose electrode.

A continuous extracorporeal monitoring system for blood glucose employing an electrochemical sensor is described. The sensor, about the size of a nickel, is rapid, is specific for glucose, generates its own power, and consists of two galvanic oxygen electrodes. Over one oxygen electrode is affixed a plastic matrix to which glucose oxidase is covalently bound; a blank matrix is over the other, which serves as a reference. Oxygen is consumed in the glucose-oxidase-containing matrix, decreasing the current from the underlying oxygen electrode. The current decrease is nonlinearly proportional to the glucose concentration. The sensor is clamped between small blocks of plastic fitted with inlet and outlet nipples so that blood pumped from the animal passes over the two electrodes and thence to an automated chemical analysis for comparison. Blood is collected and anticoagulant added in a double-lumen catheter. Blood is withdrawn at the rate of 1 cc. per hour. Results obtained by use of the system in rabbits are reported. The capacity of the system to continuously monitor changes in blood glucose produced by repeated glucose tolerances is shown in hypo-, normo-, and hyperglycemic animals. Some properties of the system and its calibration are discussed.

Animals↗