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Biomedical subjects

O E Winsett

Publications and source records attributed to O E Winsett.

9 recordsLinked to original sources
PubMed1988

Renal transplantation in the infant and young child.

Fourteen renal transplantations were performed in 13 children, aged 5 years or younger, including three infants. The mean duration of follow-up was 68 months, with a range of 14 to 203 months. Eleven children are alive; of these, nine had prolonged graft function. Graft survival rate was 92% at one year and 73% at two and five years following surgery. Sustained catch-up growth occurred in all growth-retarded children who underwent successful transplantation. At this writing, the oldest patient is 20 years of age and a junior in college; all school-age children are functioning at the appropriate grade level, except one, who is one year behind. The youngest child is 3 years old and is developing normally. Infants and young children appear to be good candidates for renal transplantation.

Child Development↗
PubMed1988

Renal transplant dysfunction: MR evaluation.

The results of 45 MR examinations were prospectively compared with the clinical course and biopsy results in 38 renal transplant patients to determine the role of MR in evaluating allograft dysfunction. Twenty-six patients underwent allograft biopsy. In eight patients in whom the biopsy was performed more than 48 hr after MR examination and in 19 patients who did not have a biopsy, the subsequent clinical course was sufficiently diagnostic to determine the specific cause of the transplant dysfunction. Corticomedullary differentiation, graded from 0 to 3, was not helpful in separating rejection (n = 20) from acute tubular necrosis (n = 9), drug toxicity (n = 7), pyelonephritis (n = 2), or normal grafts (n = 7) because of overlap between groups (sensitivity =; 60%, specificity = 60%). In the six patients with two or more MR studies, serial changes in corticomedullary differentiation were not consistent and could not be used to diagnose rejection. When any abnormality of allograft sinus fat, size or shape, or corticomedullary differentiation was considered, the sensitivity for the diagnosis of rejection approached 80%; however, specificity was low (48%). We conclude that MR imaging is not sufficiently accurate to replace transplant biopsy and therefore has a limited role in the evaluation of transplant dysfunction.

Cyclosporins↗
PubMed1987

Calcium and magnesium content of skeletal muscle. Studies in subjects undergoing diagnostic testing for malignant hyperthermia.

Ca2+ and Mg2+ contents were measured and compared among three different malignant hyperthermia susceptible (MHS) diagnostic groups. No difference was found among mean values for Ca2+ content, whereas Mg2+ content was greater in MHS muscle. Variance of measured values was unequal and greatest among MHS muscles, suggesting a possible abnormal distribution associated with MHS. Although more muscle fibres with Ca2+ less than or equal to 12 mumol g-1 were observed in MHS muscle, this difference was not statistically significant. In contrast, non-parametric analysis showed that the population of Mg2+ values was significantly greater in the MHS muscle. This study suggests that the distribution of Ca2+ and Mg2+ values is different in MHS muscle as a result of unknown genetic factors associated with the disease.

Calcium↗
PubMed1987

Comparison of Ca++ uptake and spontaneous Ca++ release from sarcoplasmic reticulum vesicles isolated from muscle of malignant hyperthermia diagnostic patients.

Inward Ca++ transport and spontaneous Ca++ release activities were compared among sarcoplasmic reticulum (SR) membrane fractions isolated from human skeletal muscle in patients undergoing malignant hyperthermia (MH) diagnostic contracture testing. Two different membrane fractions were isolated, a heavy (8-12,000 X g) and light (12-48,000 X g) fraction, from each diagnostic subject. The rates of inward Ca++ transport were faster in light SR compared to heavy SR, but no statistically significant difference was observed among MH diagnostic groups. Spontaneous Ca++ release occurred at optimum Ca++ preload in all SR fractions and this preload did not differ among MH diagnostic groups. Optimal Ca++ preload for rate of spontaneously released Ca++ was greater in light SR compared to heavy SR. Similarly, rate of Ca++ release was faster in light SR than in heavy SR, but no difference in rate of spontaneously released Ca++ was observed among MH diagnostic groups. Amount of Ca++ released did not differ among SR fractions and it did not differ among diagnostic groups. In contrast to previous studies showing a defect in Ca++-induced Ca++ release, the mechanisms related to spontaneous Ca++ release and to oxalate-facilitated inward Ca++ transport, as measured in this study, appear to be normal in SR from human MH skeletal muscle.

Calcium↗
PubMed1986

Gastrin stimulates growth of colon cancer.

Gastrin is trophic for normal gastric and colonic mucosa. We examined the potential trophic effects of chronic gastrin administration on the growth of mouse colon adenocarcinoma (MC-26). Thirty-three mice bearing transplantable MC-26 colon cancers were treated with varying doses (125, 250, or 500 micrograms/kg/day) of pentagastrin. Significant increases in tumor weight and DNA content were observed. Fundic mucosal weight and DNA content in these mice showed a dose-related trophic response. The weight of control fundic mucosa was 10 mg and rose to 20, 45, and 65 mg with increasing doses of gastrin. The DNA content of control fundic mucosa was 155 micrograms and rose to 220, 340, and 480 micrograms as the dose of gastrin was increased. Pentagastrin stimulated growth of the MC-26 colon cancer, but the threshold for gastrin-stimulated tumor growth was different from that of normal mucosal growth. The hyperplastic response of the fundic mucosa was increased by increasing gastrin doses; whereas, colon cancer hyperplasia was maximal at the lowest dose tested (125 micrograms/kg/day) and did not increase further with increasing doses of hormone. Mice bearing gastrin-stimulated tumors died at a significantly greater rate than did mice with untreated tumors (80% of control mice and none of the treated mice were alive at day 55). The effects of gastrin treatment on the growth of MC-26 colon cancer persist after treatment is discontinued; mice with tumors that were treated with gastrin for either 7 or 14 days and in which the treatment was stopped were all dead by 35 or 28 days, respectively, after the end of treatment.

Adenocarcinoma↗
PubMed1985

Complications of vascular access for hemodialysis.

This study of 533 vascular access sites for long-term hemodialysis in patients with end-stage renal disease, accumulating more than 12,000 patient months, indicated that primary arteriovenous fistula (AVF) is the procedure of choice. The group receiving primary AVF had the greatest duration of patency: 84% at three years compared to 70% for the group receiving polytetrafluoroethylene (PTFE) grafts and less than 50% for those receiving bovine carotid artery heterografts (BCAH). Furthermore, the primary AVF group had fewer complications (25 complications in 273 fistulas) than either the BCAH group (61 in 58 grafts) or the PTFE group (171 in 202 grafts). No complication resulted in death in the primary AVF group, but seven deaths resulted from complications of the access in the graft groups, further solidifying the position of the primary AVF as the procedure of choice for chronic hemodialysis access.

Adolescent↗
PubMed1985

Rapid and repeated blood sampling in the conscious laboratory rat: a new technique.

A method for obtaining repeated blood samples from conscious rats by translumbar vena cava puncture is presented. Studies performed at laparotomy enabled us to select a 5/8-in., 25-gauge needle as the ideal instrument for aspirating blood. The awake rat is held prone by an assistant and the needle inserted at the level of the first lumbar vertebra in the coronal plane at an angle of 45 degrees from the vertical. We performed the procedure 350 times in 30 rats (100-300 g) at weekly intervals for 8 wk. Each time, we have obtained 2 ml of blood. The time required for obtaining 30 samples is 15-20 min. There have been no complications and only three deaths (mortality rate, 0.9% per puncture); in all three instances the rats jerked free, lacerating the vena cava. The procedure has been performed in guinea pigs and hamsters, with equal ease, without morbidity or mortality. This new technique permits rapid, atraumatic, repeated samplings from awake animals with no morbidity and minimal mortality.

Animals↗