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Biomedical subjects

R D Schultz

Publications and source records attributed to R D Schultz.

At least 91 records · Page 5Linked to original sources
PubMed1985

Eversion endarterectomy of the superficial femoral artery and end-to-side anastomosis to the deep femoral artery. An alternative to extended profundoplasty.

The success of aortofemoral reconstruction in patients with superficial femoral artery occlusion depends on the restoration of a satisfactory pulsatile flow to the deep femoral artery. In 18 patients with multilevel disease, widespread involvement of the deep femoral artery, and poor distal outflow, we performed an eversion endarterectomy of the proximal segment of the superficial femoral artery and constructed an end-to-side anastomosis between this segment and the distal deep femoral artery. In 10 patients, the reconstruction was performed after thrombectomy of the occluded aortofemoral graft, and in 8 the two reconstructions were simultaneous. The actuarial patency rate was 93.5 percent at 1 year and 75.2 percent at 5 years. Four late femorodistal bypasses were performed that gave an actuarial limb salvage rate of 68.8 percent at 1 year and 61.6 percent at 5 years. In selected cases, this technique is a valid alternative to an extended profundoplasty or to a femorodistal bypass.

Aged↗
PubMed1985

Abdominal aortic aneurysm in elderly patients. Selective management based on clinical status and aneurysmal expansion rate.

The records of 125 patients 75 years of age or older with a diagnosis of unruptured abdominal aortic aneurysm were reviewed. Operative mortality was 4.3 percent in 69 patients considered at low risk and 39.8 percent in 13 patients at high risk who underwent aneurysmectomy shortly after diagnosis. Forty-three patients with an asymptomatic abdominal aortic aneurysm initially measuring 3.5 to 6 cm did not undergo aneurysmal resection and were followed for 6 to 72 months (mean 24 months) with serial echography. The mean enlargement rate was 0.48 cm/year. In the 43 patients, resection of the abdominal aortic aneurysm was performed for aneurysmal expansion to greater than 6 cm, development of symptoms, or a sudden change in aneurysmal diameter. Two patients were lost to follow-up, 21 underwent elective resection, aneurysms ruptured in 2, 9 died from other causes, and 9 were alive and asymptomatic at last follow-up. An aggressive surgical approach seems appropriate, even in the asymptomatic elderly patient with a small aneurysm of 4.5 to 6 cm. Serial echographic measurement appears useful in determining which patients with a very small aneurysm of less than 4.5 cm or who are considered to be high risk surgical candidates require elective aneurysmectomy.

Actuarial Analysis↗
PubMed1985

The canine lymphocyte: effect of streptolysin O on the proliferative response of canine lymphocytes.

The effects of Streptolysin O (SLO) on canine peripheral blood lymphocytes were studied using the lymphocyte blastogenesis test (LBT). Canine lymphocytes stimulated with SLO produced a response that was similar to the response obtained with the commonly used phytomitogens: phytohemagglutinin (PHA), concanavalin A (CON A) and pokeweed mitogen (PWM). When SLO was added to any of the phytomitogens and incubated with canine lymphocytes, an additive or stimulatory response was obtained. However, mixing the phytomitogens in any combination did not produce a similar additive or stimulatory response. The results were interpreted to mean that in the canine system, the binding of SLO to lymphocytes does not sterically interfere with receptors for PHA, CON A, or PWM. Additionally, SLO may stimulate a population of lymphocytes that is distinct from that stimulated by the phytomitogens. Moreover, it would appear that the phytomitogens probably stimulate the same or an overlapping population of lymphocytes. Experiments using enriched lymphoid cell populations were used to characterize the lymphocytes stimulated by phytomitogens and SLO. Lipopolysaccharides from two different bacteria were unable to cause a significant lymphoproliferative response.

Animals↗
PubMed1985

Enhanced intraphagocytic killing of Brucella abortus in bovine mononuclear cells by liposomes-containing gentamicin.

In vitro intraphagocytic killing of Brucella abortus in bovine mononuclear leukocytes was enhanced by cationic, anionic, and neutral multilamellar liposomes-containing gentamicin. Free gentamicin not entrapped in liposomes. and liposomes without antibiotic did not enhance intraphagocytic killing of B. abortus in bovine phagocytes. In vivo killing of B. abortus in guinea pigs was also enhanced by liposomes-containing gentamicin when compared to free gentamicin. Liposomes-containing alpha tocopherol acetate failed to enhance in vivo killing of B. abortus.

Animals↗
PubMed1985

Thoracic aorta-femoral artery bypass: indications, technique, and late results.

Retroperitoneal descending thoracic aorta-femoral artery bypass was performed in 18 patients over an 11-year period. The reconstruction was carried to both femoral arteries in 12 patients; in the other 6, only a single femoral artery was revascularized. The operative indication in Group 1 (3 patients) was infection of a previous aortoiliac reconstruction; in Group 2 (12 patients), occlusion of a previous aortoiliac reconstruction; and in Group 3 (3 patients), aortoiliac occlusive disease in which a direct transabdominal procedure was considered hazardous. Follow-up ranged from 6 months to 9 years (mean, 40 months). Cumulative patency rate was 96 +/- 3.9% at 1 year and 85 +/- 8.1% at 5 years. No alterations of serum creatinine and blood urea nitrogen values were recorded seven days and 6 months after operation. Retroperitoneal thoracic aorta-femoral artery bypass is a useful technique for accomplishing lower limb revascularization in patients in whom exposure or availability of the abdominal aorta poses a specific hazard.

Aged↗
PubMed1985

Constrictive calcific pericarditis following coronary arterial bypass surgery.

A case of postsurgical constrictive calcific pericarditis is reported. The unusual features of this case are the short interval (two months) from surgery to the development of pericarditis and the involvement of the coronary arterial grafts, resulting in tearing of the vessels and the death of the patient during decortication.

Aged↗
PubMed1985

Role of insects in the transmission of bovine leukosis virus: potential for transmission by stable flies, horn flies, and tabanids.

The ability of stable flies (Stomoxys calcitrans), horn flies (Haematobia irritans), and tabanids (Diptera: Tabanidae) to transmit bovine leukosis virus (BLV) was investigated. Stable flies and horn flies were fed on blood collected from an infected cow, and the flies' mouthparts were immediately removed, placed in RPMI-1640 medium, ground, and inoculated into sheep and calves. Infection of sheep occurred with mouthparts from as few as 25 stable flies or 25 horn flies. However, sheep were not infected when removal of stable fly mouthparts was delayed greater than or equal to 1 hour after blood feeding. Infection of calves occurred after inoculation of mouthparts removed immediately after feeding from as few as 50 stable flies or 100 horn flies. Infected blood, applied by capillary action to the mouthparts (labella) of 15 deer flies (Chrysops sp) and a single horse fly (Tabanus atratus) caused infection in each of 2 sheep. Infection did not occur in 2 calves inoculated daily for 5 days with mouthparts from 50 horn flies collected after feeding on a BLV-infected steer. Four calves receiving bites from 75 stable flies interrupted from feeding on a BLV-positive cow also were not infected. Seronegative cattle held for 1 to 4 months in a screened enclosure with positive cattle in the presence of biting flies were not infected with BLV. The feeding behavior of each insect is discussed to assess their potential as vectors of BLV.

Animals↗
PubMed1985

Unusual observations on a serologically negative bluetongue virus infected bull.

A Holstein bull named "Regency" born in New York in July 1968, maintained in an artificial insemination (AI) stud for 9 years, unremarkable from the point of view of health history or semen production, was discovered "by accident" to have bluetongue (BT) virus (BTV) in his semen. A microscopic study in 1975 and 1977 revealed unusual cytoplasmic vacuoles in the sperm of "Regency" prompting us to send semen to A. J. Luedke, USDA-ARS, Denver, Colorado, USA, to attempt virus isolation. Serotype 13 BTV was isolated from the semen. Serum sent with the semen was negative for antibody by the agar gel immunodiffusion (AGID) and complement fixation (CF) tests. Annual AGID serologic tests begun in 1975 and continuing to the present have been negative for antibody to BTV for all bulls in this AI stud. "Regency" was moved to Auburn, Alabama, USA in 1978 and further studies were performed. The bull was maintained with the Veterinary School herd. The BT serologic status of the cattle did not change during the year the bull was in the herd nor were the cows he bred or their calves serologically positive for BT. Studies on insemination of cattle with experimentally contaminated semen indicated that 5X10(4) infectious doses of BTV were required for infection. These results suggest that since "Regency's" semen did not infect cows, the semen probably contained less than this amount of virus. The rete testis was cannulated, rete fluid collected, a testis removed and virus isolation attempted.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Seven-year experience with polytetrafluoroethylene as above-knee femoropopliteal bypass graft. Is is worthwhile to preserve the autologous saphenous vein?

A 7-year experience with 90 polytetrafluoroethylene (PTFE) femoropopliteal bypass grafts in the above-knee (AK) position is presented. The 5- and 7-year actuarial patency rate was 58.3%. No statistical difference was found between the patency rate of this series and that of a group of 17 AK and 77 below-knee (BK) femoropopliteal bypass grafts performed during the same period with the autologous saphenous vein (ASV). During the follow-up period (range 6 to 84 months, mean 42 months) a new bypass in a more distal location was required in 20 limbs. The ASV was available in seven of the eight PTFE graft failures and in only one of the 12 ASV failures. The 3-year patency rate of these new groups was 58.3% and 16.7%, respectively (p less than 0.02). Eighteen of the 48 deaths occurring during the follow-up period were related to atherosclerotic heart disease, whereas only one patient underwent coronary artery bypass grafting. Five hundred patients randomly selected from our series of myocardial revascularization procedures were reviewed. In five a femorodistal reconstruction was performed before coronary artery bypass, and in only two (0.4%), the ASV was not available. PTFE use in the AK position may be a reasonable alternative to the ASV to preserve it for additional treatment of more distal occlusive disease. There is no evidence that such a need exists for further treatment of coronary artery disease.

Aged↗
PubMed1984

Incorporation of a follicle stimulating hormone used for embryo transfer in cattle into multilamellar liposomes.

A commercially available follicle stimulating hormone preparation (FSH-P) was successfully incorporated into multilamellar vesicles (liposomes). Multilamellar liposomes were found to contain 9.39 +/- 1.14 mg FSH-P (n=4) per 100 mg phospholipid or approximately 19.0% of the original material used to form the liposomes. A 1% solution of Triton X-100 incubated with liposomes containing FSH-P for one-half hour at 37 degrees C released 33% of the entrapped FSH-P; more than 99% of the entrapped FSH-P was released when liposomes were incubated with a 2% solution of Triton X-100. Entrapment of FSH-P increased proportionally to the mole percentage of stearylamine used in liposome formation, suggesting that FSH-P is entrapped in the aqueous interstices of the cationic liposomes. Entrapment of FSH-P in stable liposomes suggests that these multilamellar vesicles may be useful as a FSH-P delivery vehicle used for the superovulation and embryo transfer of food animals.

Journal Article↗
PubMed1984

Effect of bacterial lipopolysaccharide on bovine polymorphonuclear neutrophil migration in vitro.

The in vitro effects of Escherichia coli 026:B6 lipopolysaccharide (LPS) on random migration of bovine polymorphonuclear neutrophils (PMN) was investigated. Treatment of peripheral blood leukocytes (PBL) with LPS significantly inhibited PMN migration. These inhibitions were observed at a threshold concentration of 5.0 micrograms/2.0 X 10(6) PBL. PMN migration inhibition was eliminated in PBL by the addition of polymyxin B, which binds the Lipid A moiety of LPS. Treatment of isolated PMNs with LPS significantly enhanced migration. Enhanced migrations were observed at threshold concentration of 2.5 micrograms/4.0 X 10(6) PMN. Collectively these findings indicate that the inhibition was caused by leukocyte inhibitory factor (LIF) production in PBL cultures, whereas enhancement was probably caused by PMN activation. These results provide further insight into the effects of LPS on in vitro bovine PMN migration by its distinct actions on different cells of PBL.

Animals↗
PubMed1984

Factors affecting the infectivity of lymphocytes from cattle with bovine leukosis virus.

Peripheral blood mononuclear cells were obtained from 13 bovine leukosis virus infected cattle and inoculated subcutaneously into 29 recipient adult steers to determine (a) the number of mononuclear cells (equivalent amount of blood) necessary to cause infection and (b) factors influencing infectivity of mononuclear cells from bovine leukosis virus-infected animals. A total of 55 inoculations were made. Inoculation of 1 X 10(4), 2 X 10(4) and 5 X 10(4) mononuclear cells caused seroconversion in 12%, 57% and 62% of steers, respectively. No infections occurred with 1 X 10(3) or 2 X 10(3) mononuclear cells. Cattle infected for longer than 24 months and those animals greater than three years of age were more likely to cause infection with 1 to 5 X 10(4) mononuclear cells than were cattle infected for less than 24 months or animals less than three years of age. Lymphocytes from cattle with persistent lymphocytosis caused more infections when 1 X 10(4) or 2 X 10(4) mononuclear cells were inoculated, than did lymphocytes from nonpersistent lymphocytosis cattle; however, both groups were equally infectious when 5 X 10(4) mononuclear cells were inoculated. No differences were found in infectivity of experimentally vs naturally exposed animals.

Age Factors↗
PubMed1984

Experimentally induced Cooperia oncophora infection in calves: lymphocyte blastogenic and delayed hypersensitivity responses.

Lymphocytic responses in peripheral blood and visceral lymph to Cooperia oncophora antigen and skin tests were determined in 35 Holstein male calves that were inoculated orally with single or multiple doses of C oncophora infective larvae. Several calves were vaccinated or given immune serum before larvae were inoculated. Antigen-specific in vitro blastogenesis of blood and lymph lymphocytes and delayed-type hypersensitivity reactions were observed in several inoculated, vaccinated, and/or passively immunized calves. Most calves that had delayed skin reactions also had in vitro lymphocyte responses to C oncophora antigen. The lymphocyte and skin responses were inconsistent and variable in time of onset--the earliest lymphocyte response occurring 7 days after calves were inoculated. A cellular immune response was induced by both dermal vaccination and oral inoculation; however, passive immunization by IV administration of immune serum simultaneously with inoculation did not have an apparent effect on the cellular response, as measured by the lymphocyte blastogenesis test or dermal testing. Although cellular immune responses were observed in several calves infected with C oncophora, there was no apparent relationship between the specific responses and number of nematodes establishing infection in calves after either single- or multiple-dose oral inoculations.

Animals↗
PubMed1983

Effect of antioxidants on the proliferative response of canine lymphocytes in serum from dogs with vitamin E deficiency.

The in vitro effect of vitamin E and 3 other antioxidants--ethoxyquin, 2-mercaptoethanol, and ascorbic acid--on proliferation of canine lymphocytes was examined. Lymphocytes from 2 groups of dogs given a vitamin E-deficient diet or whelped from a bitch fed such a diet were cultured with pooled samples of serum from dogs fed a vitamin E-deficient diet or whelped from a bitch fed such a diet, or normal canine serum, and stimulated with phytohemagglutinin. Added vitamin E enhanced the responsiveness in serum from the dogs with vitamin E deficiency, but not in normal canine serum. A similar effect was noted with added ethoxyquin and 2-mercaptoethanol. Ascorbic acid had no effect on proliferation in either serum pool. These results indicated that depressed lymphocyte responsiveness seen with serum from vitamin E-deficient dogs may, at least in part, be due to a loss of antioxidant activity in this serum.

Animals↗
PubMed1982

Assays of cellular immunity.

Numerous cellular assays are available to study the response or activities of mononuclear and polymorphonuclear cells in domestic species. When the assays, most developed originally to study rodent or human cells, are adapted to the cells of domestic species, minor or major modifications have been necessary. Furthermore, interpretation of results of the assays with cells from domestic species are not always consistent with those obtained in the original system, and it should not be expected that the assays will always provide results that can be interpreted similarly among species. Application and additional experience with these techniques, as well as new techniques, will provide a foundation for our understanding of the importance of cellular mechanisms in immunity of domestic species.

Animals↗