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Biomedical subjects

E A Wilson

Publications and source records attributed to E A Wilson.

At least 37 records · Page 2Linked to original sources

Expression of plasminogen activator (PA) and a PA inhibitor in human granulosa cells from preovulatory follicles.

Studies with rat ovarian cells indicate that proteolytic enzymes, such as plasminogen activator (PA), play a role in the tissue remodeling that occurs before ovulation. In the rat, gonadotropins appear to increase granulosa cell tissue-type plasminogen activator (t-PA) content by increasing the cellular concentration of t-PA mRNA as well as by modulating the activity of a specific PA inhibitor (PAI). We obtained granulosa cells from preovulatory follicles of women undergoing either in vitro fertilization or gamete intra-fallopian tube transfer in order to evaluate the roles of PA and PAI in human ovulation. Samples of granulosa cell total RNA were hybridized with probes for t-PA, urokinase-type PA, PAI type 1 (PAI-1), or inhibin A-chain (as a control). Northern analyses revealed that the RNA of granulosa cells from preovulatory follicles contained little or no detectable PA mRNA. In contrast, two species of PAI mRNA were detected in relative abundance. The signal intensity produced by the PAI-1 probe varied by about 8-fold among patient samples, suggesting that PAI-1 may be useful as a marker of follicular maturation and differentiation. These results demonstrate that human granulosa cells collected immediately before ovulation contain PA inhibitor mRNA, yet have little or no PA mRNA.

Cells, Cultured↗

Dietary history and nutritional state in treated coeliac patients.

The gluten content and nutritional adequacy of the diet of a group of adult coeliac patients supposedly following a gluten-free diet for at least one year were assessed. Results were considered in relation to the nutritional state of these patients, determined by anthropometric measurement, and the histological appearance of jejunal biopsies taken at the time of nutritional assessment. Imperfect gluten avoidance, mild malnutrition and mild histological abnormalities on jejunal biopsy were frequent findings. A careful dietary and nutritional assessment when considered in light of histological findings at jejunal biopsy helps to identify the causes of persisting symptoms or malnutrition in treated coeliac patients. A normal jejunal biopsy in a malnourished patient whose dietary compliance is good should prompt a search for an alternative diagnosis.

Adolescent↗

Natural history of diabetes presenting age 40-69 years: a prospective study of the influence of intensive dietary therapy.

Two hundred and twenty-three newly-diagnosed symptomatic diabetic patients with onset age 40-69 years enrolled in a prospective study of intensive dietary management of diabetes were observed for a period of six years and the data obtained is analysed. The variables studied were weight and fasting levels of plasma glucose and insulin, and of serum total cholesterol and triglyceride. These tests were monitored throughout the study and in addition the oral glucose tolerance test was analysed at entry to the study, after six months intensive dietary management and again after 72 months. Blood pressure, electrocardiogram and the presence of posterior tibial artery pulsation were recorded at entry to the study and at 36 months and 72 months. Approximately 80 per cent of the patients were managed solely by dietary restriction for the entire six years, but 25 patients received oral hypoglycaemic drugs and 26 required insulin treatment. Weight, and fasting glucose and triglyceride values fell in the first few months of intensive dietary management. Analysis of possible risk factors in survivors and patients dead at six years showed no significant differences, apart from a higher mean age at diagnosis in those who died. During the six years of intensive dietary management the mortality from all causes in these diabetic patients was no greater than that for the general population of Northern Ireland.

Adult↗

Classification of endometriotic implants by morphologic appearance and capacity to synthesize prostaglandin F.

The severity of the symptoms of endometriosis has not always correlated well with the anatomic severity of the disease. This lack of correlation may be due to variations in the metabolic activity of the endometriotic implants present at different stages of the disease. Because prostaglandin F (PGF) has been implicated as a hormonal mediator of the clinical symptoms of endometriosis, PGF synthesis and content was measured in implants from 14 patients with mild, moderate, severe, or extensive disease. To assess whether PGF production was related to the status of implants, the authors classified implants, based on gross and histologic criteria, as petechial or reddish; intermediate or brown; or powder-burn or black. PGF production of implants from patients with mild or moderate disease was greater than that of implants from patients with severe or extensive disease (P less than 0.05), and PGF content was similar for all stages of endometriosis. Petechial implants produced twice the amount of PGF than intermediate implants (P less than 0.05), which in turn produced more PGF than powder-burn implants (P less than 0.05). Powder-burn implants did not have the in vitro capacity to produce PGF, and the amount of PGF contained in implants of all classes was similar. Therefore, endometriotic implant PGF production and possibly other biochemical activities are dependent on the physical status of the implant. The classification of implants by morphologic appearance may afford additional assistance in determining the prognosis of the disease and in the examination of the subtle effects of the disease on symptoms.

Adult↗

Long-term follow up of experimental microvascular grafts using Doppler ultrasound.

Non-directional Doppler ultrasound was used to determine patency in prosthetic microvascular grafts in 30 rats over 24 weeks. Examinations were carried out every two weeks and exploration and arteriography were used at intervals during the study to confirm the Doppler findings. Two rats died and were excluded from the study. Twenty-six grafts were patent at the time of examination and these were correctly assessed by the Doppler technique. However, only one of two occluded grafts was correctly identified. Our results suggest that while this technique is sensitive, its specificity is low, and graft exploration may still be required to confirm patency. Doppler ultrasound may prove a useful non-invasive tool for long-term follow-up of experimental microvascular grafts if the false positive rate can be reduced by improved technique and further experience.

Animals↗

Experimental microvascular polytetrafluoroethylene grafts: 6-month patency.

The efficacy of 1-mm internal-diameter polytetrafluoroethylene as a microvascular prosthesis is unclear. In this study, 8-mm-long segments of this material were implanted into the femoral arteries of 30 rats. Animals were examined every 2 weeks up to 6 months by Doppler ultrasound. Cumulative patency by the life-table method was 86.7 percent at 6 months. There were 26 patent grafts, 2 occlusions, and 2 deaths. Intimal hyperplasia adjacent to the anastomoses was seen in the native arteries. The pseudointima lining the grafts was cellular near the anastomoses but usually acellular in midgraft regions. It is concluded that if early failure does not occur, then good long-term patency is possible with 1-mm polytetrafluoroethylene in this setting and that patency is not dependent on development of a cellular pseudointima. Longer graft segments should be evaluated in future studies.

Actuarial Analysis↗

Studies on the surgical induction of endometriosis in the rat.

As a model to examine the pathophysiologic attributes of endometriosis, attempts were made to surgically induce the disease in the rat by autotransplanting endometrial or uterine tissue to the peritoneum. Rats (n = 46) were randomly assigned to one of four surgical techniques: (1) four uterine squares sutured to the peritoneal cavity; (2) uterine luminal lavages instilled into the peritoneal cavity; (3) endometrial scrapings flushed into the peritoneal cavity; and (4) sham-operated controls. Rats were examined at various days after surgery for the presence of endometrial implants. The autotransplantation of uterine squares to the peritoneal cavity was the only treatment that yielded healthy endometriotic implants. These implants grew into ellipsoidal cystic structures that were composed of both endometrial glands and stroma and were found to contain prostaglandin F (202 ng/mg) at concentrations similar to those measured in uterine tissue (205 ng/mg). To examine the effect of surgically induced endometriosis upon fecundity, rats (n = 40) were autotransplanted with uterine squares or were sham operated and mated. The presence of ectopic endometrial tissue reduced the number of pups at term by 48% and the number of day 14 embryos by 28% (P less than 0.05). Peritoneal adhesions were greater in rats with induced endometriosis than in sham-operated controls (P less than 0.05); however, in rats with induced endometriosis, no differences were noted in the severity of adhesions between pregnant and nonpregnant rats. Endometriotic implants underwent complete regression in the day 14 pregnant rat but had doubled in size in the nonpregnant rat. At term, the endometriotic implants were larger than in the day 14 pregnant rat (P less than 0.05) and similar to their original size. The successful growth and development of surgically transplanted endometrial tissue in the rat offers a research model that can be used to study those aspects of endometriosis that cannot be adequately investigated in women.

Analysis of Variance↗

Effect of estradiol and progesterone on human chorionic gonadotropin secretion in vitro.

Many of the substances known to control the secretion of pituitary gonadotropins also modulate the secretion of human chorionic gonadotropin (hCG) by the placenta. In order to study the effect of estrogens and progestins on hCG secretion, term placental explants were cultured in culture media for 144 hours. During the culture period, hCG secretion increased after 48 hours, and a fortyfold increase was observed after 144 hours (p less than 0.001). Compared to concentrations of hCG in control cultures, secretion of hCG was markedly suppressed in the presence of progesterone 2.25 X 10(-5)M (p less than 0.001), a concentration similar to that found in term placental tissue (1.7 +/- 0.2 micrograms/gm of tissue). Suppression of hCG by progesterone occurred in a dose-response manner (r = -0.9100, p less than 0.01). Estradiol, an important steroid modulator of pituitary gonadotropins, did not significantly suppress the secretion of hCG, except in pharmacologic concentrations (10(-4)M), and physiologic concentrations of estradiol had no effect on the suppression of hCG by progesterone. These results suggest that the mechanism by which progesterone suppresses the secretion of hCG differs from the manner in which steroids modulate the secretion of pituitary gonadotropins.

Cesarean Section↗

Accuracy of serum human chorionic gonadotropin concentrations and ultrasonic fetal measurements in determining gestational age.

Prior to 60 days' gestation, the maternal serum concentration of human chorionic gonadotropin (hCG) can predict the estimated date of confinement, but later in pregnancy, hCG concentrations vary widely. The current study was performed to compare the accuracy of hCG measurements with other determinants of gestational age. Fifteen patients in whom gestational age was documented were monitored prospectively throughout pregnancy. One to two determinations of hCG (beta subunit) were obtained during the first 60 days. Then, ultrasonographic measurements of crown-rump length were obtained between 8 and 16 weeks' gestation and two measurements of biparietal diameter were performed between 18 and 32 weeks. These results were compared to actual dates of gestation. The mean (+/- SD) difference between gestational age predicted by single measurements of hCG and actual gestational age was 3.2 +/- 2.5 days (r = 0.94, p less than 0.0001), which compared favorably with estimates by crown-rump measurements (6.7 +/- 6.5 days) and measurements of biparietal diameter (6.3 +/- 5.3 days). These results demonstrate that hCG measurements during the first 60 days accurately predict gestational age and complement ultrasonic determinations of gestational age used later in pregnancy.

Anthropometry↗

Retrograde ejaculation: etiology and treatment via the use of a new noninvasive method.

Retrograde ejaculation (RE) is not a common infertility problem, but has increased in incidence recently due to surgical aggressiveness in pelvic and genital malignancies. However, RE is the most common cause of aspermia, or absence of ejaculate at orgasm. Meanwhile, surgical or drug therapy methods have not been very promising in regaining normal antegrade ejaculation. As yet, the standard procedures for treatment of RE involve the artificial insemination of either nonprocessed or processed (via centrifugation and resuspension) postcoital voided bladder contents. RE specimens in this study were collected after postcoital voiding into a TEST buffer and resuspended in TEST-yolk buffer. The urine effects on the voided spermatozoa were studied. The technique employed in this study assists in the recovery and reconstitution of RE fit for artificial insemination.

Adult↗

A rapid method for repurifying partly degraded radiolabeled steroids.

This rapid method for repurifying radiolabeled steroids from degraded products is based upon differential partitioning of intact and degraded molecules between aqueous-phase solution and anhydrous diethyl ether. Results compare favorably with those by liquid-chromatographic methods.

Chromatography, High Pressure Liquid↗

Hysterosalpingography and laparoscopy: a comparative study.

Twenty-six women were evaluated with both hysterosalpingography and laparoscopy. The hysterosalpingograms were reviewed independently by two radiologists. Postdrainage films were obtained in 19 of 26 patients. A high false-negative rate (44.9% overall) and low specificity (20.6%) were observed. The postdrainage film contributed to a correct diagnosis in only four of 38 tubes evaluated by the first radiologist and in none evaluated by the second radiologist. Hysterosalpingography is valuable as a screening procedure for identifying abnormals but is not specific in differentiating tubal adhesions from tubal obstructions. It is recommended that preliminary films not be obtained routinely and that postdrainage films be reserved for cases where fluoroscopic and spot-film findings are equivocal.

Evaluation Studies as Topic↗

Determination of gestational age by serum concentrations of human chorionic gonadotropin.

To examine the accuracy and predictability of human chorionic gonadotropin concentrations in determining gestational age, serum concentrations of human chorionic gonadotropin (beta-subunit) were measured during the first 157 days after last menses. Using the regression curve generated, human chorionic gonadotropin concentrations obtained during the first 60 days accurately predicted the day of gestation. The difference (mean +/- SD) between the human chorionic gonadotropin-predicted estimated date of confinement and the estimated date of confinement established by known dates of last menses was 3.1 +/- 2.3 days. In patients followed to parturition, the difference between human chorionic gonadotropin-estimated gestational age and gestational age by physical assessment of the neonate was 8.1 +/- 7.1 days. After 60 days' gestation, human chorionic gonadotropin concentrations vary widely and are of little value in predicting gestational age. In addition to documenting conception, early human chorionic gonadotropin determinations accurately date the gestation and complement other clinical and biophysical methods for determining gestational age that are frequently used later in pregnancy.

Chorionic Gonadotropin↗

Stimulation of human chorionic gonadotropin secretion by glucocorticoids.

The effects of glucocorticoids on hormone secretion by human placenta in organ culture were studied. The addition of cortisol resulted in a fourfold increase in human chorionic gonadotropin (hCG) secretion over that in untreated cultures after 144 hours' incubation (P less than 0.05), and a twofold increase in hCG was observed in the presence of cortisone (P less than 0.01). Dexamethasone stimulated hCG secretion in a dose-response manner (r = 0.9542; P less than 0.01). Progesterone, which suppresses hCG under these conditions, decreased the cortisol-enhanced secretion of hCG (r = -0.9794; P less than 0.01). No change in the secretion of human chorionic somatomammotropin was observed, but glucocorticoids increased heat-stable alkaline phosphatase activity (P less than 0.001). The physiologic significance of glucocorticoid effects on placental hormone synthesis is discussed.

Alkaline Phosphatase↗

Effect of dextran-coated charcoal on radioimmunoassays of unconjugated estriol in serum.

Lipid interference in the radioimmunoassay of steroids can cause an apparent variation in post-prandial serum concentrations of unconjugated estriol. The effects of increased concentrations of dextran-coated charcoal (15--60 g/l) in the radioimmunoassay of estriol standards with and without triglycerides were studied. All concentrations of dextran-coated charcoal used in this study eliminated the previously observed effects of estriol-lipid partitioning. When we used similar concentrations of dextran-coated charcoal, we found that serum cortisol levels in pregnant women declined significantly during the day (P less than 0.001), but no significant variation in estriol concentrations was observed. These results indicate that the previously reported diurnal variation in serum unconjugated estriol concentrations attributed to steroid-lipid partitioning can be eliminated by increasing the concentration of dextran-coated charcoal in assays using this method of separation.

Charcoal↗