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Biomedical subjects

R D Schultz

Publications and source records attributed to R D Schultz.

At least 73 records · Page 4Linked to original sources
PubMed1987

In vitro effects of prostaglandin E1, prostaglandin E2, indomethacin, histamine, and tuftsin on chemiluminescence response of bovine polymorphonuclear leukocytes.

The in vitro effects of prostaglandin E1 (PGE1), prostaglandin E2 (PGE2), indomethacin, histamine, and tuftsin on the chemiluminescence response of bovine polymorphonuclear cells (PMN) were determined. Addition of PGE1, PGE2, indomethacin, and histamine in vitro significantly suppressed the chemiluminescence response of bovine PMN's, whereas tuftsin had no effect. Suppression was dependent upon the continued presence of PGE1, PGE2, and histamine in the culture media. However, indomethacin's suppressive effect remained even after it was removed from the culture media. Hydrogen peroxide generated chemiluminescence was suppressed by high concentrations of indomethacin and histamine. Results of this study suggest possible pharmacologic or regulatory mechanisms for certain of these immune modulators in the control of the oxidative burst reaction of bovine PMN's.

Alprostadil↗
PubMed1987

The effects of glucocorticosteroids on the chemiluminescence response of bovine phagocytic cells.

The effects of corticosteroids on the chemiluminescence response of bovine phagocytic cells were determined both in vitro and in vivo. The in vitro addition of hydrocortisone or dexamethasone had no significant effect on the chemiluminescence response of leukocytes in a whole blood or purified polymorphonuclear leukocyte (PMN) population. Cattle that received a single 20 mg dose of dexamethasone or three 20 mg doses of dexamethasone (given 24 hours apart) demonstrated the expected effects on the bovine leukogram (leukocytosis, neutrophilia, lymphopenia, eosinopenia, and monocytosis) and also demonstrated the expected suppressive effect on lymphocyte response to phytohemagglutinin (PHA). However, neither a single nor multiple dexamethasone treatment(s) had an effect on the chemiluminescence response of phagocytes in whole blood, but significantly enhanced the chemiluminescence response of the purified PMN leukocyte population. There was no significant difference between the two dexamethasone treatment groups in either the degree or duration of the effects observed in the chemiluminescence or lymphocyte response assays.

Animals↗
PubMed1987

Inhibition of bovine lymphocyte response to phytohemagglutinin by a specific 5-lipoxygenase inhibitor.

AA861, a specific 5-lipoxygenase inhibitor, inhibited bovine lymphocyte response to phytohemagglutinin (PHA). Mitogen-stimulated cultures of mononuclear cells produced leukotriene B4 (LTB4) in 24 hours. The production of LTB4 was completely inhibited by concentrations of AA861 that inhibited mitogen-induced 3H-thymidine incorporation. The inhibition of lymphocyte proliferation was totally reversed by LTB4 but not by leukotriene C4 or leukotriene D4. The inhibition of interleukin-2 (IL-2) production by AA861 was also completely reversed by addition of exogenous LTB4 to lymphocyte cultures. Thus, endogenous LTB4 production appeared to be necessary for PHA-induced IL-2 production and lymphocyte proliferation.

Animals↗
PubMed1987

Failure of vaccine or virulent strains of canine parvovirus to induce immunosuppressive effects on the immune system of the dog.

It is generally believed that canine parvovirus (CPV) is immunosuppressive and that immunosuppression plays an important role in the pathogenesis of canine parvovirus disease. However, there is little experimental evidence to support this assertion. The effects of virulent and vaccine strains of CPV on natural effector (NE) cell activity, antibody-dependent cell-mediated cytotoxicity (ADCC), chemiluminescence (CL) of neutrophils, lymphocyte response to mitogen, specific antibody response to CPV, and dermal reaction to phytohemagglutinin (PHA) were examined. Neither a virulent nor a vaccine strain of CPV significantly suppressed the immune system. The only potential effect noted was that dogs infected with the virulent strain of CPV developed a transient peripheral blood leukopenia. It was concluded that CPV does not cause immunosuppression and that immunosuppression does not play a significant role in the pathogenesis of canine parvovirus disease.

Animals↗
PubMed1987

Reoperation for femoral anastomotic false aneurysm. A 15-year experience.

An experience on the surgical treatment of anastomotic false aneurysms during the last 15 years was reviewed. Fifty-nine were femoral anastomoses complicated by false aneurysm appearance requiring surgical excision. They represented 2.9% of all femoral anastomoses performed, whereas they represented 3.3% when considering reconstruction in which the femoral artery was the distal anastomosis. Reconstructions with distal anastomosis performed on the femoral artery were primarily involved (58 of 59), whereas grafts with "take off" from the femoral artery were rarely affected (p less than 0.05). A higher incidence of false aneurysm formation was demonstrated in hypertensive patients (p less than 0.05) as well as those who previously had femoral thromboendarterectomy (p less than 0.01). Infection was considered a causative factor even if it developed before (6-14 months) false aneurysm appearance. When a false aneurysm was resected, the best hemodynamic reconstruction, to avoid recurrence, was considered a bypass with distal anastomosis performed end-to-end on the femoral artery (p less than 0.05). The surgical treatment of choice was false aneurysm resection and graft interposition. However, a reanastomosis in the presence of small false aneurysms, when technically possible, has been successfully performed. Both treatments allowed good long-term results.

Aged↗
PubMed1987

Survival of Listeria monocytogenes in milk during high-temperature, short-time pasteurization.

Milk from cows inoculated with Listeria monocytogenes was pooled for 2 to 4 days and then heated at 71.7 to 73.9 degrees C for 16.4 s or at 76.4 to 77.8 degrees C for 15.4 s in a high-temperature, short-time plate heat exchanger pasteurization unit. L. monocytogenes was isolated from milk after heat treatment in six of nine pasteurization trials done at 71.7 to 73.9 degrees C and in none of three trials done at 76.4 to 77.8 degrees C. An average of 1.5 to 9.2 L. monocytogenes cells was seen in each milk polymorphonuclear leukocyte before heat treatment in 11 of 12 pasteurization trials. Noticeable degradation of leukocytes with intracellular listeria was detected in unpasteurized milk after 3 days of storage at 4 degrees C, and by 4 days of storage leukocytes had deteriorated to cellular debris, suggesting that holding unpasteurized milk refrigerated for 4 or more days would eliminate a protective effect leukocytes may provide for increasing heat resistance of L. monocytogenes. Results indicate that under the conditions of this study, L. monocytogenes can survive the minimum high-temperature, short-time treatment (71.7 degrees C, 15 s) required by the U.S. Food and Drug Administration for pasteurizing milk.

Animals↗
PubMed1987

Cystic adventitial degeneration of the femoral artery: is evacuation and cyst excision worthwhile as a definitive therapy?

A case of cystic adventitial degeneration of the left common femoral artery in a patient with localized left groin pain, normal distal pulses, and normal arteriographic findings is reported. This patient was first treated with evacuation and cyst excision. Recurrence was noted after 20 months, and an excision of the cyst and a segment of the common femoral artery with graft interposition was required. At gross examination, the cyst was unilocular and contained gelatinous material. The cyst appeared to be situated in the tunica adventitia and did not communicate with the vascular lumen. No synovial lining was present. Histologically, it was similar to a ganglion cyst with contents rich in hyaluronic acid. A review of the literature was undertaken to determine the results of treating this lesion. The disease is rare. All senior authors of case reports were contacted to construct follow-up information. A high incidence of recurrence was noted in patients treated by evacuation and cyst excision. We believe that total cyst excision with the involved artery and graft interposition at the femoral site can be done easily, safely, and with virtually no chance for recurrence.

Arterial Occlusive Diseases↗
PubMed1986

Multiple pulmonary neurofibromas with hypoxemia. Occurrence due to pulmonary arteriovenous shunts within the tumors.

A 62-year-old woman with multiple neurofibromas of the lung was found to have severe hypoxemia due to right-to-left shunting within the tumors. Pulmonary angiograms demonstrated that the major area of shunting was in a large tumor mass in the right lower lobe. Pathologically the neurofibromas were vascular with hyperplastic small arteries and arterioles and large dilated veins. Multiple pulmonary neurofibromas are rare; and, to our knowledge, never previously reported in association with pulmonary arteriovenous shunting.

Female↗
PubMed1986

Ontogeny of natural killer cell activity and antibody dependent cell mediated cytotoxicity in pigs.

Cells from pigs of various ages were collected from peripheral blood, mesenteric lymph node, spleen and thymus and their ability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) and natural killer (NK) cell activity was determined. ADCC against chicken red blood cell (CRBC) was present in cells from peripheral blood, lymph node and spleen, but was absent in thymic cells. There were no age-related differences in ADCC to CRBC and cells from fetal pigs had similar activities to cells from adult pigs. Maximal cytotoxicity against CRBC was found in the polymorphonuclear leukocyte (PMN) cell fraction. In contrast to the good response against CRBC, PMN cells were not lytic in the ADCC assay when PI3 virus-infected cells were used as target cells. Peripheral blood lymphocytes (PBL) had low but significant lytic activity against PI3 virus-infected cells in the presence of high concentrations of specific antiserum. NK cell activity against K562 target cells was readily detected in PBL of pigs older than 2 weeks but was not observed with cells from spleen, lymph node or thymus from pigs of any age. PBL of pigs younger than 2 weeks of age had low but detectable NK activity: however, fetal pigs had no NK activity against K562 target cells. In contrast, when PI3 virus infected Vero cells were used as target cells, NK cells were detected in spleen and PBL, but not lymph nodes or thymus, of pigs greater than one day of age. Similar to the absence of activity to K562, none of the lymphoid cells from fetal pigs had NK activity against PI3 virus-infected Vero cells. The present results suggest that the effector cells that mediate ADCC are distinct from those that mediate NK activity in that cells mediating ADCC develop earlier and are found in different organs than the NK cells. Additionally, the cells that mediate NK activity against viral infected cells may be different from those that mediate NK activity for K562 target cells; however, regardless of the target, NK cells are not present before birth in the pig.

Age Factors↗
PubMed1986

Effect of corticosteroid on porcine leukocytes: age-related effects of corticosteroid inhibition on porcine lymphocyte responses to mitogens.

The effects of prednisolone sodium succinate on the responses of porcine lymphocytes to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) were investigated. Sensitivity of peripheral blood lymphocytes (PBL) to the synthetic glucocorticoid, prednisolone, was related to age of the lymphocyte donor. The greatest sensitivity was found in PBL from animals less than one week old; PBL from animals between 2 to 4 months retained some glucocorticoid sensitive cells; whereas, PBL from animals older than 6 months were exceptionally resistant to steroid. Similar age-associated sensitivities were found for lymphocytes from lymph node, spleen and thymus. Significant differential sensitivities among the various lymphoid organs were found with the thymic lymphocyte possessing the greatest sensitivity to steroid and the PBL lymph node and splenic lymphocytes possessing the highest resistance to the suppressive effects of steroid. The age related differences in sensitivity to steroid did not appear to be caused by differences in the number of steroid receptors because lymphocytes from susceptible and resistant animals had similar numbers of receptors. The results suggest that the age related sensitivity may be associated with a higher percentage of sensitive thymic-derived lymphocyte in the PBL, lymph node and spleen of the younger animals. Results of this study also suggest that the adult pig (6 months) should be classified as a steroid resistant species.

Aging↗
PubMed1986

Immunomodulation with killed Propionibacterium acnes in guinea pigs simultaneously vaccinated with Brucella abortus strain 19.

Immunomodulation with killed Propionibacterium acnes was attempted in guinea pigs simultaneously vaccinated with Brucella abortus strain 19. Two groups, each comprised of 9 guinea pigs, were injected by different routes (s.c. and or i.v.) with 1.4 mg of P. acnes and 5 X 10(8) CFU of B. abortus, S-19, while 3 other groups each received either P. acnes, B. abortus S-19, or saline (s.c.). The antibody titers to B. abortus measured at 6, 10 and 14 weeks after vaccination indicated no significant (P less than 0.01) response in the 2 groups immunopotentiated with P. acnes concurrent with B. abortus S-19 vaccination. The delayed hypersensitivity response to 3 Brucella antigens conducted 8 weeks after immunization did not show a significant difference between the B. abortus S-19 vaccinated group compared with the 2 groups immunopotentiated and vaccinated. However, the proliferative response of lymphocytes to the B. abortus soluble antigen diluted 1:100 indicated significantly enhanced blastogenesis in the (s.c.) immunopotentiated and immunized guinea pigs compared with the B. abortus S-19 vaccinated group. A slightly enhanced response was also observed in the group immunopotentiated (i.v.) and vaccinated (s.c.). The guinea pigs were challenged with B. abortus strain 2308 and necropsied 4 weeks later. The mean splenic CFU of the Brucella in the group immunopotentiated (i.v.) and vaccinated (s.c.) was significantly decreased when compared with the guinea pigs vaccinated with B. abortus S-19 alone. These findings indicated that P. acnes administered simultaneously with B. abortus S-19 vaccine was able to augment the immune response in guinea pigs. Immunomodulation as evidenced by enhanced clearance of B. abortus from the spleens of immunopotentiated animals was presumably brought about by activated macrophages or a T-cell mediated cytolytic mechanism or both.

Adjuvants, Immunologic↗
PubMed1986

A technique for profunda femoris artery reconstruction. Hemodynamic assessment and functional results.

A modified technique of profunda femoris artery reconstruction is presented. In case of occlusion of the superficial femoral artery, the proximal segment of this vessel is rolled over the profunda femoris artery as a patch after an endarterectomy has been performed. This technique has been performed in 110 patients (131 limbs) during the last 14 years. Five-year actuarial patency rate (life-table method) was 65.3%. With measurements obtained from nine biplanar angiograms, glass models of three different methods of profunda femoris reconstruction were constructed. The model representing this modified technique of profundaplasty showed less turbulence than the others. The results of this study validate the use of this type of profundaplasty in clinical practice.

Actuarial Analysis↗
PubMed1986

Refractoriness of rhesus monkeys to repeated ovarian stimulation by exogenous gonadotropins is caused by nonprecipitating antibodies.

Oocytes obtained from superstimulated rhesus monkeys are needed for in vitro fertilization experiments. The animals become refractory to repeated ovarian stimulation by pregnant mare serum gonadotropin (PMSG). Production of antibodies against PMSG was suspected. Antibodies were not detected by gel-diffusion tests, but were found using ELISA procedures in sera from all monkeys that had been treated with PMSG. Sera from seven of nine treated monkeys had antibodies that cross-reacted with FSH-P. An ovarian stimulation test using golden hamsters showed that sera from PMSG-treated rhesus monkeys completely blocked superstimulation of follicle development and ovarian weight gain by PMSG. This study demonstrates that the refractoriness of rhesus monkeys to repeated ovarian stimulation by PMSG is due to the production of nonprecipitating antibodies to PMSG that effectively block the activity of PMSG on the ovary. Formation of these antibodies may preclude use of other gonadotropin preparations in refractory monkeys. Alternative ovarian stimulation procedures avoiding use of gonadotropin preparations need to be developed to permit repeated treatment of rhesus monkeys for multiple oocyte collection.

Animals↗
PubMed1986

Aortic and renal atherosclerotic disease.

From 1972 to 1985, 39 patients underwent simultaneous aortic and renal revascularization. Thirty-six patients were hypertensive, whereas three patients were normotensive and the lesion of the renal artery was treated prophylactically. The operative mortality rate was 10 per cent. At late follow-up study, 65.6 per cent of the patients with hypertension were "cured" or "improved." Improvement of renal function was obtained in nine of 13 survivors with reduced renal function preoperatively. In addition, 133 patients who underwent aortic reconstruction without repairing the lesion of the renal artery because it was clinically "silent" were reviewed. Five patients experienced renal failure in the early postoperative period. At late follow-up study (a mean of 30 months), three of the 126 survivors died of renal failure and only 18 were hypertensive. Respectable results can be achieved after simultaneous aortic and renal revascularization. However, the increased operative mortality and morbidity warrants a conservative approach in patients considered at high risk or in whom stenosis of the renal artery causes few or no clinical problems.

Aorta↗
PubMed1986

Thoracic aorta as source of inflow in reoperation for occluded aortoiliac reconstruction.

We reviewed our experience with reoperations for recurrent obstruction occurring after aortoiliac or aortofemoral reconstruction. Patients who underwent successful transfemoral thrombectomy of the aortofemoral graft or femorofemoral crossover graft were excluded from the study. A more proximal source of inflow to revascularize the ischemic limbs was required in the remaining 35 patients. Bilateral reconstruction was performed in 22 patients. Operative indication was rest pain or necrosis in 36 limbs and severe claudication in 21 limbs. Preoperative ankle/brachial pressure index (API) ranged from 0.05 to 0.61. Thirteen patients (21 limbs, group I) underwent transabdominal reoperation. Since the transabdominal approach was considered hazardous because of multiple previous operations, the remaining patients underwent retroperitoneal descending thoracic aorta-femoral artery bypass (15 patients, 25 limbs; group II) or axillofemoral bypass graft (7 patients, 11 limbs; group III). No statistically significant difference was present between the three groups in regard to the operative indication, API, and angiographically determined outflow (analysis of variance, p greater than 0.2). Axillofemoral bypass was preferred in patients with severe chronic pulmonary disease. Postoperative deaths (2 of 35 patients) and morbidity (6 of 35 patients) had a similar incidence in the three groups (p greater than 0.2). Follow-up ranged from 3 to 120 months (mean 37 months). The 5-year actuarial patency rate was 80.5% for group I and 80.2% for group II. In group III it was statistically lower (32.9%, p less than 0.05). Serial measurement showed a significant decrease of API in group III compared with group I and group II. We conclude that retroperitoneal descending thoracic aorta-femoral artery bypass is a valid alternative to transabdominal reoperation when exposure or availability of the abdominal aorta poses a specific hazard and is preferable to axillofemoral bypass in terms of long-term patency and hemodynamic results.

Adult↗
PubMed1986

Effects of aflatoxin on the growth performance and immune responses of weanling swine.

Aflatoxin (AF)-contaminated ground corn was mixed with a commercial swine ration to yield 2 concentrations (500 mg of AFB1/kg of feed [A] and 300 mg of AFB1/kg [B]) and was fed to 2 groups of pigs. Groups A and B were fed the AF-containing ration, whereas control group C was fed the same commercial ration mixed with ground corn devoid of AF. A comparative analysis of the average weight gain per pig in each of the treatment groups, compared with that in the control group, indicated a significantly (P less than 0.01) greater weight gain in the control group. The average feed conversion rate was also significantly (P less than 0.01) lower in group A pigs, compared with that in the control group. The humoral immune response to Erysipelothrix rhusiopathiae, measured by enzyme-linked immunosorbent assay, did not reveal a significant difference among groups; there were no consistent differences observed in the proliferative responses of lymphocytes to mitogens. In contrast, a significant (P less than 0.05) reduction in complement titers was observed, whereas an increase in serum immunoglobulin G and M values occurred in the AF-treated group A, compared with that in group C. Gross enlargement of the liver, substantiated by histologic evidence of toxic damage to the hepatic parenchyma, revealed that AF at concentrations of 500 mg/kg of feed was toxigenic and produced an adverse effect on the growth rate, feed efficiency, and general well-being of young pigs.

Aflatoxins↗