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Biomedical subjects

W K Vaughn

Publications and source records attributed to W K Vaughn.

At least 109 records · Page 6Linked to original sources
PubMed1985

Polyspermy: effect of varying stimulation protocols and inseminating sperm concentrations.

Results from 198 cycles of in vitro fertilization (IVF) were examined to identify factors in the subsequent development of polyspermy. Polyspermy occurred in 24 of 235 fertilized oocytes and was equally likely in mature and immature oocytes. No significant difference in polyspermy was demonstrated between the stimulation protocol using human menopausal gonadotropin (hMG) and those using clomiphene citrate (CC) or combined hMG/CC. The incidence of polyspermy was no different after insemination of oocytes with concentrations of progressively motile sperm ranging from 250,000 to 500,000. Although polyspermy continues to be a problem in IVF, we have been unable to identify possible predisposing mechanisms for its development.

Clomiphene↗
PubMed1985

Effect of the number of inseminating sperm and the follicular stimulation protocol on in vitro fertilization of human oocytes in male factor and non-male factor couples.

The effect of sperm concentration and follicular stimulation protocol on in vitro fertilization of human oocytes is not well established. Comparison was made of three inseminating concentrations (250,000, 375,000, and 500,000 progressively motile sperm/oocyte) and three protocols (human menopausal gonadotropin [hMG], clomiphene citrate [CC], and combination hMG/CC) on the fertilization rate of mature and immature oocytes in couples with male factor and non-male factor infertility. In non-male factor couples, total fertilization rates for CC, hMG, and hMG/CC were 70.3%, 54.5%, and 68.8%, respectively, while total fertilization rates at the varying number of inseminating sperm were not significantly different. Mature oocytes were more likely than immature oocytes to fertilize. Among semen male factor couples, there was no difference in fertilization by stimulation protocol; however, insemination with the higher number of inseminating sperm resulted in an increased fertilization rate.

Clomiphene↗
PubMed1985

A longitudinal study of the detection of otitis media in the first two years of life.

A number (210) of children were followed longitudinally through the first two years of life with pneumatic otoscopy and electroacoustic immitance, tympanometry, at every physician encounter. Tympanometry proved to have a high predictive value (86%) for detecting normal ears but relatively poor predictive value (58%) for detecting abnormal ears when utilized as a routine screening procedure with every clinic visit. In part the tympanometrically abnormal ears which appeared normal in otoscopic exam were temporally related to recent episodes of otitis and concurrent upper respiratory congestion, but many were unrelated to detectable middle ear pathology. These observations detract from the utility of tympanometry as a screening tool for middle ear pathology.

Acoustic Impedance Tests↗
PubMed1985

Complication of insulin-dependent diabetic pregnancies by preeclampsia and/or chronic hypertension: analysis of outcome.

The significance of hypertensive complications of insulin-dependent diabetic pregnancies (IDDP) has not been well examined since the early reports of Pedersen, which demonstrated an increased risk of neonatal death in women with pregnancy induced hypertension (PIH). To assess the effect of both PIH and chronic hypertension (CH) on outcome of IDDP managed using contemporary obstetrical and diabetic management, we reviewed the records of all 199 IDDP delivered at our institution over a 7-year period. Patients were classified as having PIH (Group 1, n = 37), CH (Group 2, n = 18) or both (Group 3, n = 4) on the basis of standard clinical criteria. All other IDDP were placed in the control group (Group 4, n = 140). Comparing all groups, significant differences were found for maternal age (P less than .0001) and distribution among White's Classes (P less than .0001). There was no significant difference in estimated gestational age (EGA) at delivery, birthweight, Apgar scores, hypoglycemia, hyperbilirubinemia, or congenital anomalies. Intrauterine fetal death (IUFD) was no more common in Groups 1, 2 or 3 than in Group 4; however, IDDP with CH were significantly more likely to have had previous stillbirths than IDDP with PIH (P = .011) or control IDDP (P = .017). Contrary to common clinical belief, the "stress" of CH and PIH did not offer protection to the newborn in the development of RDS or HMD. In fact, Group 3 infants had a higher rate of HMD than control infants (P = .024).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Methyldopa therapy and outcome in cadaveric renal transplantation.

Methyldopa therapy for hypertension after renal transplantation could affect graft outcome adversely, since methyldopa inhibits suppressor cells. To study effects of methyldopa on transplant outcome, we analyzed prospective data on 1,648 hypertensive, first-allograft recipients; 545 patients used methyldopa and 1,103 patients did not. One-year graft functional survival was 66% and 67% for all patients using and not using methyldopa respectively. No increased acute rejection occurred related to methyldopa. During the one to six years of follow-up, no adverse effects on graft survival could be attributed solely to methyldopa except that graft survival among white recipients using methyldopa was diminished late after transplantation (P less than .05). Patient survival was not affected by methyldopa. Azathioprine and prednisone therapy may avert the suppressor cell inhibition by methyldopa. Its effect on kidney transplant outcome is not significant except in whites late in the course of graft function; methyldopa use when clinically indicated appears safe.

Actuarial Analysis↗
PubMed1985

Lack of influence of donor-recipient differences in subtypic HLA-A,B antigens (splits) on the outcome of cadaver renal transplantation.

Data collected prospectively on 3811 cadaver renal transplants performed between June 1977 and July 1982 by the 42 member institutions of the South-Eastern Organ Procurement Foundation (SEOPF) were analyzed to determine whether donor-recipient differences in sub-typic HLA-A,B specialties (splits) influenced outcome. The number of HLA-A,B antigens matched and mismatched between each donor and recipient was calculated in three ways: (1) considering all antigens and splits as distinct (not matched); (2) considering all splits as only matched with their corresponding typic antigen (but not with each other); and (3) considering all splits as matched with both their corresponding typic antigen as well as each other. Overall graft survival, graft loss from irreversible rejection, and patient survival stratified by the level of HLA match were the same using all three methods. In addition, using multivariate Cox regression analysis, the strong association between good HLA matching and increased graft survival was the same using all three methods of matching. Patients with a given number of mismatched antigens had no significant decrease in survival when additional splits were considered mismatched with each other or their corresponding typic antigen. These results suggest that matching of typic HLA-A,B antigens plays a highly significant role in reducing graft rejection but that donor-recipient differences in splits have a negligible effect on graft outcome.

Graft Survival↗
PubMed1985

Renal allograft cell infiltrates associated with irreversible rejection.

All 74 renal transplant biopsies performed between 11/78 and 8/84 at Duke University and Durham VA Medical Centers having cellular infiltrates that could be phenotyped by immunoperoxidase labeling were examined to identify histologic and immunopathologic features which correlated with rejection. Monoclonal antibodies identifying hematopoietic cells, T cells, T helper cells, T cytotoxic-suppressor cells, macrophages, and B cells were used, and each phenotype population was graded separately based on pattern of infiltration: cortical-diffuse (CD), perivascular (PV), and cortical-aggregate (CA). Histologic and immunofluorescent studies were used to evaluate acute (humoral) and cellular types of vascular and interstitial inflammation. By univariate analysis, patients having irreversible rejection within 10 weeks postbiopsy (n = 23) had significantly higher grades of both acute vascular (humoral) inflammation and TC-S cell infiltrates in a CD pattern as compared with those who had good graft function. Multivariate (Cox regression) analysis was also performed considering biopsy changes, therapy before and after biopsy, and intervals between transplant, rejection onset, and biopsy--as well as other factors potentially affecting the biopsy or graft outcome. Of nine cell phenotype-pattern combinations, only TC-S infiltrates in a CD pattern were associated with a significant (P less than 0.03) relative risk (RR) of subsequent failure from rejection (RR = 8.2). When those cases with significant acute (humoral) inflammation (n = 10) were excluded, the relative risk of TC-S-CD infiltrates increased to 46.4 (P less than 0.04). These findings indicate that the location, as well as the number and type of cell infiltrates are critical in evaluating cellular forms of rejection, and that the extent of diffuse, cortical TC-S infiltration on biopsy provides the greatest predictor of subsequent irreversible graft failure.

Acute Disease↗
PubMed1985

Relation of blood-free to blood-inclusive postmortem lung water measurements in sheep.

Our purpose was to see if the postmortem weight ratio of extravascular lung water to blood-free dry lung (blood-free ratio) was related to similar ratios in blood-inclusive lung and in blood. We developed linear regressions of blood-free ratio on ratios for blood-inclusive lung and blood together and for blood-inclusive lung alone for 73 sheep studied under 11 different protocols and for two subgroups of sheep, one with plasma space expansion and the other without expansion. The relation of ratios of blood-free to blood-inclusive lungs was different between the two subgroups. Although all regressions were highly correlated, the fits of the blood-free ratio on ratios for blood-inclusive lung and blood together were better than for blood-inclusive lung alone. The mean error of prediction of extravascular lung water for all sheep was significantly less for the regression of blood-free ratio on ratios for blood and blood-inclusive lung together (11 g) than for blood-inclusive lung alone (18 g). This study shows that weights of lung homogenate and blood samples before and after simple oven drying can be used to provide accurate inexpensive estimates of postmortem extravascular lung water.

Animals↗
PubMed1985

Reduction of infarct size with intracoronary perfluorochemical in a canine preparation of reperfusion.

The effect of low-dose (15 ml/kg) intracoronary perfluorochemical (Fluosol-DA) on infarct size, regional myocardial blood flow, and ventricular function was studied in 20 anesthetized closed-chest dogs subjected to 11/2 hr of proximal left anterior descending occlusion. In this preparation reperfusion was simulated with fibrinolytic therapy. The animals were randomly assigned one of two treatment groups and given 15 ml/kg of either oxygenated intracoronary perfluorochemical (n = 9) or saline (n = 11). Contrast ventriculograms were obtained at baseline, 1 hr after occlusion, and at 24 hr after reperfusion and were analyzed with a radial fractional shortening method. Regional myocardial blood flow was measured with radioactive microspheres. At 24 hr the area at risk was defined in vivo with monastryl blue staining and the area of necrosis was estimated after incubation of left ventricular slices with triphenyltetrazolium chloride. No significant changes were noted in heart rate, blood pressure, pulmonary capillary wedge pressure, or dP/dt during the experimental protocol. Infarct size was significantly reduced (p less than .02) in the perfluorochemical-treated group, both when expressed as a percentage of the total left ventricular mass (7.9 +/- 1.7% vs 14.7 +/- 2.5%) and as a percentage of the area at risk (20.1 +/- 5.0% vs 46.8 +/- 8.5%). This was associated with significant improvement in fractional shortening in the jeopardized zone at 24 hr after reperfusion. Although endocardial blood flow was significantly greater in the central ischemic zone and lateral region at risk immediately after reperfusion in the perfluorochemical-treated group, no difference was found 1 hr after reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Morphologic changes in long-term saphenous vein bypass grafts.

A retrospective autopsy study was performed in 56 patients who had undergone saphenous vein bypass graft (SVBG) surgery 12 to 168 months prior to death. Twenty-five grafts had atherosclerosis, 66 grafts had fibrointimal proliferation, and 26 grafts were fibrotic with total occlusion. No significant differences were noted among the three morphologic groups with regard to age of the patient or number of native coronary arteries severely narrowed. Vein grafts with fibrointimal proliferation occurred with greater frequency in patients with systemic hypertension (p less than 0.001), and atherosclerotic grafts were more prevalent in patients with hypercholesterolemia (p less than 0.02). Therefore, the presence of risk factors may determine the type of change that occurs in saphenous vein bypass grafts: systemic hypertension leads to fibrointimal proliferation, whereas hypercholesterolemia leads to atherosclerotic change.

Adult↗
PubMed1984

Benefits of HLA-A and HLA-B matching on graft and patient outcome after cadaveric-donor renal transplantation.

Data collected prospectively on 3811 renal transplantations performed between June 1977 and July 1982 by the 42 member institutions of the South-Eastern Organ Procurement Foundation were analyzed to determine the influence of donor-recipient HLA-A and HLA-B matching on patient and graft outcome. Well-matched recipients were more likely to have received kidneys from outside their own centers, were more highly presensitized, included fewer blacks, and were more likely to have lost an earlier graft. Multivariate Cox regression analysis that included these and six other potential confounding variables revealed a significant association (P less than 0.001) between good HLA-A and B matching and increased graft survival. The difference in mean (+/- S.E.) actuarial graft survival between recipients worst matched and best matched for HLA-A and B antigens increased with time: 55 +/- 2 per cent as compared with 64 +/- 4 per cent at six months and 18 +/- 4 per cent as compared with 44 +/- 7 per cent at four years. Poor HLA matching of donor with recipient provided the greatest relative risk (2.16) of irreversible graft rejection of all the variables examined. Among patients with functioning grafts, well-matched recipients had lower serum creatinine levels and received significantly smaller amounts of glucocorticoids. Our findings indicate that good HLA-A and B matching is highly dependent on a system for sharing organs among institutions, and results in decreased graft rejection, better long-term graft function, and less need for post-transplantation immunosuppression.

Adult↗
PubMed1984

Severe functional declines, work disability, and increased mortality in seventy-five rheumatoid arthritis patients studied over nine years.

Seventy-five patients with rheumatoid arthritis (RA) were reviewed 9 years after an extensive evaluation which included quantitative measures of functional capacity. These patients had received multiple intraarticular injections of thiotepa with corticosteroids early in their course, but appear demographically and functionally similar to other RA patients who had not received this therapy. Severe morbidity was seen over the 9-year period in the 55 surviving patients, including significantly lower overall functional capacity in 92% of patients studied, lower grip strength in 93%, and longer button test results in 84%. Work disability occurred in 85% of patients under age 65 who had been working full-time at disease onset. There was increased mortality at the 9-year review, similar to most reported series of RA patients from referral centers; however, a significant increase in neoplasia, which was of concern because of the use of intraarticular thiotepa, was not seen. In terms of functional capacity, including responses to questions about ability to perform activities, walking time, and the button test, those patients who had died prior to review had significantly lower baseline values than did those who survived. Of the 75 patients, 20 had died and 51 had lost significant functional capacity over a 9-year period, documented by quantitative measures of functional capacity.

Activities of Daily Living↗
PubMed1984

Tubal patency and pelvic adhesions at early second-look laparoscopy following intraabdominal use of the carbon dioxide laser: initial report of the intraabdominal laser study group.

It has been suggested that the carbon dioxide (CO2) laser, by virtue of its hypothetical capabilities for precise incisions, minimization of tissue handling and bleeding, and shortened operating time, may improve the success rate of gynecologic infertility surgery. To assess this hypothesis, a multicenter prospective study was performed to assess tubal patency and adhesion formation at early second-look laparoscopy after intraabdominal laser surgery. Procedures performed included salpingoneostomy, fimbrioplasty, lysis of adhesions, vaporization of endometriosis, and ovarian wedge resection. The results were compared with those of another multicenter prospective study that utilized nonlaser reconstructive pelvic surgery. Use of the CO2 laser was found to result in a greater tubal patency rate at the time of the second-look procedure. Adhesions present at the time of the second-look procedure were reduced from initial presentation at most sites; however, nonlaser infertility surgery appeared to have equal or greater efficacy in the prevention of adhesion formation at most sites. Thus, the CO2 laser does not appear to be a panacea for the treatment of tuboperitoneal causes of infertility. Pregnancy rates following intraabdominal use of the CO2 laser remain to be established.

Adolescent↗
PubMed1984

Seroepidemiology of hepatitis B in Tennessee prisoners.

A prevalence serosurvey was performed on an 11.7% sample of the 6,503 adult male inmates in Tennessee prisons. On the basis of the sample, 0.9% of the prisoners possessed hepatitis B surface antigen, and 29.5% had one or more serum markers for hepatitis B virus (HBV). Thirty-two possible risk factors were analyzed for association with possession of HBV serum markers. The significant risk factors for possession of HBV markers in this population were found to be age, intravenous drug use while not incarcerated, intravenous drug use while incarcerated, race, education, military service history, and duration of prior and current imprisonments, in that order of importance. Given the modest contribution of incarceration to overall risk, mass immunization of prisoners against HBV seems unwarranted. Prisoners with unusually long sentences or who use intravenous drugs in prison are subgroups at particularly high risk. The logistic model can be used to target a serological screening and immunization program.

Adolescent↗