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Biomedical subjects

W W Hurd

Publications and source records attributed to W W Hurd.

At least 19 recordsLinked to original sources
PubMed1998

Cocaine augments contractility of the pregnant human uterus by both adrenergic and nonadrenergic mechanisms.

OBJECTIVE: Our purpose was to evaluate the mechanisms of cocaine's effect on both spontaneous and agonist-induced contractility of pregnant human myometrium. STUDY DESIGN: Myometrium was obtained from 42 women at term who were undergoing cesarean section. Myometrial strips were suspended in contraction baths and isometric contractions were measured. Tissue was exposed to various combinations of cocaine, prazosin, desipramine, benzoylecgonine, and procaine. Spontaneous contractility and the contractile responses to increasing concentrations of methoxamine and oxytocin were measured and compared. RESULTS: Cocaine increased spontaneous myometrial contractility by more than threefold. Prazosin, an alpha-adrenergic antagonist, blocked this effect only for the first 35 minutes of exposure. The cumulative concentration-response to the alpha-adrenergic agonist methoxamine was increased by cocaine in terms of both sensitivity and maximal response. The maximal response to oxytocin, but not the sensitivity, was increased by cocaine by an effect that could not be blocked by prazosin. CONCLUSION: Cocaine augments spontaneous and agonist-induced contractility of pregnant human myometrium by mechanisms that appear to be both alpha-adrenergic and nonadrenergic in nature.

Adrenergic alpha-Agonists↗
PubMed1998

Comparison of low-technology and high-technology monitoring of clomiphene citrate ovulation induction.

OBJECTIVE: To determine whether newer monitoring techniques, including urinary detection of the LH surge and vaginal ultrasound, offer an advantage over basal body temperature (BBT) charts alone in achieving pregnancy using clomiphene citrate (CC). DESIGN: Randomized clinical trial. SETTING: Infertility patients in an academic research environment. PATIENT(S): Forty-five women undergoing ovulation induction with CC. INTERVENTION(S): The women were assigned randomly to receive either low- or high-technology ovulation monitoring for a total of 3 ovulatory cycles. Both groups were followed with BBT charts. The high-technology group also was monitored with urinary LH kits and vaginal ultrasound. MAIN OUTCOME MEASURE(S): Cycle fecundity rates for each technique were compared statistically with use of life-table analysis. RESULT(S): Forty-five patients were studied during a total of 134 cycles. The overall cycle fecundity rate was 8%, 10% (8 of 81 cycles) for the low-technology monitoring group and 6% (3 of 53 cycles) for the high-technology monitoring group. These rates were not statistically significant when evaluated by Fisher's exact test (P = .53) or when using life-table analysis and a log-rank test (P = .48). CONCLUSION(S): These data suggest that, for initial attempts at ovulation induction with CC in unselected patients, high-technology monitoring of ovulation offers no increase in fecundity over low-technology monitoring.

Adult↗
PubMed1998

Size of the urogenital hiatus in the levator ani muscles in normal women and women with pelvic organ prolapse.

OBJECTIVE: Compare urogenital hiatus size in normal women and women with pelvic organ prolapse. METHODS: The sagittal and transverse urogenital hiatus diameters were measured and hiatus area calculated in 300 women whose support was scored using a modified Baden system. RESULTS: In women with normal support and without prior surgery, hiatus area was 5.4 cm2 (+/-1.71 standard deviation [SD], n = 197). In women with uncorrected clinical prolapse (grade 2-3), the area of the hiatus was enlarged (9.6 cm2 +/- 3.97, n = 34, P < .05) and became larger with progressive prolapse (grade 0, 5.4 cm2 +/- 1.71, n = 197; grade 1, 7.3 cm2 +/- 1.91, n = 27; grade 2, 8.3 cm2 +/- 2.45, n = 18; grade 3, 11.0 cm2 +/- 4.90, n = 16). When matched for age and parity, prolapse patients had a larger hiatus than normal women. Women with recurrent prolapse had a larger hiatus than cured women (13.3 cm2 +/- 3.86, n = 8 compared with 8.1 cm2 +/- 2.44, n = 16, P < .05) or women with recurrence after one operation (8.9 cm2 +/- 1.77, n = 18, P < .05). Hiatus size in patients surgically cured (8.3 cm2 +/- 2.44, n = 16) did not return to normal (5.4 cm2 +/- 1.71, n = 197, P < .05). Increasing area of the hiatus was correlated with an increase in anterior-posterior diameter (r2 = 0.9, P < .05), was less attributable to increased transverse diameter (r2 = 0.6, P < .05), and was not related to thickness of the perineal body (r2 = 0.0, P > .05). CONCLUSION: Increasing pelvic organ prolapse is associated with increasing urogenital hiatus size; the hiatus is larger after several failed operations than after successful surgery or single failure.

Adult↗
PubMed1997

The role of irrigation in the development of hypothermia during laparoscopic surgery.

OBJECTIVES: Our purpose was to determine the incidence and etiology of hypothermia during laparoscopic surgery and to evaluate the role of irrigation fluid temperature. STUDY DESIGN: A prospective randomized study was performed of 35 women undergoing operative laparoscopy under general anesthesia who received surgical irrigation fluid either at ambient temperature or warmed to 39 degrees C. The core body temperature was determined with use of both an esophageal sensor and a tympanic membrane sensor and was expressed as the change from baseline. Additional data collected included age, height, weight, amount of irrigation fluid and intravenous fluid used, room temperature, length of anesthesia, and amount of carbon dioxide used for pneumoperitoneum. RESULTS: Hypothermia occurred in 94% of all patients, with no difference in incidence between the groups. The minimal core temperature was lower in the ambient temperature group (-1.7 degrees +/- 0.2 degrees C) than in the warmed fluid group (-1.0 degrees +/- 0.2 degrees C). Of the variables measured, length of anesthesia and the amount of ambient temperature fluid alone explained the drop in core temperature. CONCLUSION: Hypothermia is extremely common in laparoscopic surgery and is related to the length of anesthesia and the use of ambient temperature irrigation fluid. The use of warmed irrigation fluid can decrease, but not eliminate, this drop in core temperature.

Adult↗
PubMed1997

Expectant management versus elective curettage for the treatment of spontaneous abortion.

OBJECTIVE: To determine whether the amount of intrauterine tissue was prognostic of the risk of complications associated with the management of nonviable pregnancies diagnosed in the first trimester before cervical dilatation (termed here impending abortion) with either expectant observation or elective curettage. DESIGN: Historic cohort study. SETTING: University Infertility Service. PATIENT(S): All women with nonviable pregnancies followed by the Division of Reproductive Endocrinology during a 5-year period. The patients were divided into those with significant intrauterine tissue (gestational sac > 10 mm) and those with minimal intrauterine tissue. INTERVENTION(S): Women either underwent elective curettage or were followed expectantly. MAIN OUTCOME MEASURE(S): Complication rates. RESULT(S): In 89 women with minimal tissue, no complications occurred regardless of treatment mode. In 63 women with significant intrauterine tissue, expectant management resulted in more complications (9/24) than elective curettage (1/39). In the expectant group, complications included missed abortion, septic abortion, and incomplete abortion requiring emergency curettage, with one patient requiring a transfusion. In the curettage group one uterine perforation occurred. CONCLUSION(S): In women with impending abortions and minimal intrauterine tissue, expectant treatment is safe after ectopic pregnancy has been excluded. In patients with significant intrauterine tissue, the risk of complications may be decreased by elective uterine curettage compared with expectant management.

Abortion, Threatened↗
PubMed1997

Comparison of the ultrasonic scalpel to CO2 laser and electrosurgery in terms of tissue injury and adhesion formation in a rabbit model.

OBJECTIVE: To determine the relative effect of an ultrasonic scalpel on reproductive tissue compared with CO2 laser and electrosurgery. DESIGN: Prospective, randomized animal study. SETTING: University laboratory setting. ANIMALS: Sixteen New Zealand White rabbits. INTERVENTION(S): A steel scalpel, an ultrasonic scalpel, a CO2 laser, or electrosurgery were used to perform an ovarian wedge resection and to remove the distal uterine horn. A 3-cm longitudinal incision also was made in the uterine horn. MAIN OUTCOME MEASURE(S): The number of 1-second bursts of needle-tip electrosurgery required for hemostasis, the depth and degree of coagulation necrosis, degree of fibrin deposition, and postoperative adhesion formation. RESULT(S): The amount of electrosurgery needed to achieve hemostasis was less for any of the four power techniques than for the steel scalpel, with the exception of the ultrasonic scalpel at level 5 when used on the ovary. The depth (range: 0.30 to 0.38 mm) and the degree of coagulation necrosis was not different for any of the power techniques. The fibrin score was greatest for the ultrasonic scalpel at level 5 in both the ovarian tissue and the uterine tissue. There was no difference in adhesion scores for the power techniques and the steel scalpel. CONCLUSION(S): The ultrasonic scalpel at level 3 is not different from either CO2 laser or electrosurgery in terms of hemostatic properties, coagulation necrosis, or adhesion formation in the rabbit model.

Animals↗
PubMed1996

Cocaine and beta-adrenergic receptor function in pregnant myometrium.

OBJECTIVE: Our purpose was to evaluate the in vitro effect of cocaine on beta-adrenergic receptor function in pregnant human myometrium. STUDY DESIGN: Myometrium was obtained from 25 pregnant women at term who were undergoing cesarean section but who were not in labor. Membrane preparations were assayed for cyclic adenosine monophosphate production after exposure to isoproterenol, sodium fluoride, or forskolin in the presence and absence of either cocaine or benzoylecgonine, a major metabolite of cocaine. RESULTS: Cocaine inhibited isoproterenol-induced cyclic adenosine monophosphate production in concentrations as low as 10(-8) mol/L but had no effect on cyclic adenosine monophosphate production induced by sodium fluoride or forskolin. Benzoylecgonine (10(-4) mol/L) had no effect on isoproterenol-induced cyclic adenosine monophosphate production. CONCLUSION: Cocaine is a beta-adrenergic receptor antagonist in human myometrium at concentrations as low as 10(-8) mol/L. This acute effect of cocaine may result in increased uterine contractility with adrenergic stimulation, potentially leading to increased uterine activity associated with acute cocaine use.

Cocaine↗
PubMed1996

Luteal support with both estradiol and progesterone after clomiphene citrate stimulation for in vitro fertilization.

OBJECTIVE: To determine if pregnancy rates (PRs) for clomiphene citrate (CC)-stimulated IVF-ET can be increased by luteal support with E2 and P. DESIGN: Prospective randomized crossover clinical study. SETTING: Infertile women volunteers in an academic research environment. PATIENTS: Ninety-three infertile women underwent a total of 143 IVF-ET cycle using CC for ovulation induction. INTERVENTIONS: Each woman received either no luteal support (control group) or luteal support with both oral E2 (2 mg three times daily) starting on the day of retrieval and vaginal P suppositories (100 mg twice daily) starting on the day of ET. MAIN OUTCOME MEASURE: Clinical PR. RESULTS: In 79 of 143 (55%) of the cycles, at least one embryo was transferred. Compared with the control group (n = 35 cycles), the luteal support group (n = 44 cycles) had a significantly higher PR per retrieval (control: 2% versus luteal support: 16%) and were older (control: 33 +/- 4 versus luteal support: 35 +/- 4 years; mean +/- SEM). They did not differ in terms of E2 or P levels, endometrial thickness on the day of hCG, number of follicles > 16 mm in diameter, mature oocytes retrieved, or embryos transferred. CONCLUSIONS: Luteal support with both E2 and P significantly increase the clinical PRs for CC-stimulated IVF-ET.

Adult↗
PubMed1996

Laparoscopic transillumination for the location of anterior abdominal wall blood vessels.

OBJECTIVE: To determine the efficacy of transillumination for locating abdominal wall vessels prior to trocar placement during laparoscopy. DESIGN: Prospective clinical descriptive study. SETTING: Normal human volunteers in an academic research environment. PATIENTS: Forty-seven white and 21 black women of various weights undergoing laparoscopy for clinical indications unrelated to this study. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The location and number of abdominal wall vessels visible by transillumination were recorded for each patient. RESULTS: In women of normal weight, a single vessel could be seen approximately 5 cm from the midline in > 90% of the patients, and second vessel approximately 8 cm from the midline could also be seen in 51%. The more medial vessels did not correlate with the course of the inferior epigastric vessels seen laparoscopically. The ability to see vessels was decreased significantly by the patients' weight but not by skin color. CONCLUSIONS: Superficial abdominal wall vessels may be located by transillumination in the majority of women of normal weight regardless of skin color, but is of less value in overweight and obese women. However, the deep (inferior) epigastric vessels cannot be effectively located by transillumination, and thus other techniques should be used to minimize the risk of injury to these vessels.

Abdominal Muscles↗
PubMed1995

A comparison of the relative risk of vessel injury with conical versus pyramidal laparoscopic trocars in a rabbit model.

OBJECTIVE: Our purpose was to compare the relative risk of vessel injury after use of a 5 mm conical-tipped trocar, a 5 mm pyramidal-tipped trocar, and a 10 mm pyramidal-tipped trocar in a rabbit vessel model. STUDY DESIGN: Plastic templates were placed in front of and behind 108 mesenteric vessels in 11 anesthetized New Zealand White rabbits. Laparoscopic trocars were inserted through the templates and mesentery. The incidence of vessel injury was determined at distances from the vessels ranging from 0 to 5 mm. RESULTS: The 5 mm conical trocar resulted in a vessel injury rate of 88% at 0 mm from the vessel but 0% at 1 or 2 mm. The 5 mm pyramidal trocar resulted in 100%, 88%, and 62% injury rates of 0, 1, and 2 mm from the vessels, respectively. The 10 mm pyramidal trocar resulted in a 100% injury rate at 0, 1, 2, or 3 mm from the vessels and 80% and 40% at 4 mm and 5mm, respectively. CONCLUSION: The relative risk of vessel injury is significantly increased by the use of pyramidal-tipped trocars when compared with conical-tipped trocars, especially if larger diameter trocars are used.

Animals↗
PubMed1995

Third stage of labor: analysis of duration and clinical practice.

OBJECTIVES: Our purpose was to record gestational age-specific data for third-stage duration of labor, frequencies of retained placentas (undelivered at 30 minutes), manual removal of the placenta, and hemorrhage. STUDY DESIGN: Included were 45,852 singleton deliveries > or = 20 weeks' gestation from 1984 to 1992. Odds ratios, 95% confidence intervals, and actuarial life analysis with censoring of cases with manual placenta removal were performed. RESULTS: The frequency of retained placentas (2.0% overall) was markedly increased among gestations < or = 26 weeks (odds ratio 20.8, 95% confidence interval 17.1 to 25.4) and < 37 weeks (odds ratio 3.0, 95% confidence interval 2.6 to 3.5) compared with term. The frequency of manual removal (3.0% overall) was increased among gestations < or = 26 weeks (odds ratio 9.2, 95% confidence interval 7.5 to 11.4) and < 37 weeks (odds ratio 2.8, 95% confidence interval 2.4 to 3.1) compared with term. Hemorrhage (3.5% overall) was increased among subjects with manual placenta removal (odds ratio 10.4, 95% confidence interval 9.1 to 11.9); hemorrhage was also increased among gestations < or = 26 weeks (odds ratio 3.0, 95% confidence interval 2.3 to 4.0) and < 37 weeks (odds ratio 1.2, 95% confidence interval 1.01 to 1.3) compared with term. The frequency of hemorrhage peaked by 40 minutes regardless of gestational age. Life-table analysis predicted 90% of placentas would spontaneously deliver by 180 minutes for gestations at 20 weeks, 21 minutes at 30 weeks, and 14 minutes at 40 weeks; the predicted frequency of retained placentas was 42% higher than the recorded incidence. CONCLUSIONS: The duration of the third stage decreases and the frequencies of hemorrhage and manual removal decrease with increasing gestational age. Hemorrhage was associated with manual placental removal. Life-table analysis indicated that manual removal of placentas shortened the duration of the third stage of labor, especially among preterm deliveries. A prospective trial is needed to determine whether manual placental removal can reduce hemorrhage among prolonged third stages.

Female↗
PubMed1995

Characterization of the effect of cocaine on catecholamine uptake by pregnant myometrium.

OBJECTIVE: To characterize the effect of cocaine on catecholamine uptake by myometrium from pregnant women. METHODS: Slices of myometrium obtained from nine women during elective cesarean delivery at term were incubated with [3H]-norepinephrine and various uptake inhibitors for 30 minutes. The radiolabeled material was extracted with perchloric acid, expressed as percent control (+/- standard error of the mean), and compared by one-factor analysis of variance and Fisher multiple range test. RESULTS: Myometrial uptake was inhibited by cocaine (42 +/- 9%) by neuronal (type 1) uptake inhibitors (desipramine 41 +/- 14%; N-ethylmaleimide 53 +/- 8%), and by extraneuronal (type 2) inhibitors (normetanephrine 56 +/- 19%; corticosterone 73 +/- 9%). When uptake inhibitors were used in combination with cocaine, uptake was not decreased further in the presence of neuronal inhibitors (desipramine plus cocaine 40 +/- 20%; N-ethylmaleimide plus cocaine 42 +/- 4%). However, the effect of cocaine appeared to be added to that of extraneuronal inhibitors (normetanephrine plus cocaine 25 +/- 14%; corticosterone plus cocaine 32 +/- 1%). CONCLUSION: Catecholamine uptake by myometrium in pregnant women appears to be both extraneuronal and neuronal in nature, and cocaine inhibits the neuronal portion of this uptake. This mechanism may play a role in the increased rate of premature delivery associated with cocaine abuse.

Analysis of Variance↗
PubMed1995

Decrease in myometrial beta-adrenergic receptors with prenatal cocaine use.

OBJECTIVE: To determine if cocaine use during pregnancy is associated with a reduction in the number or affinity of beta-adrenergic receptors in human myometrium. METHODS: Myometrium was obtained at cesarean delivery of five women who reported using cocaine during pregnancy and from ten controls. Saturation binding assays were performed on the myometrial membrane fractions using [125I]-cyanopindolol to determine beta-adrenergic receptor concentration and affinity. The percentages of beta 1- and beta 2-adrenergic receptors were determined in three cocaine users and four control patients by performing competition binding assays using the beta 2 antagonist ICI 118,551. Results were compared using unpaired Student t tests. RESULTS: Women who reported using cocaine during pregnancy had a significantly lower mean (+/- standard deviation) concentration of myometrial beta-adrenergic receptors than did controls (22 +/- 8 versus 52 +/- 23 fmol/mg protein, respectively). There was no difference in the receptor affinity constants between cocaine users and controls (16 +/- 2 pmol/L for both groups). The percentages of beta 1- and beta 2-adrenergic receptors in the myometrium of the cocaine-use group and control group were similar: 86 +/- 1% beta 2 in the cocaine-use group and 83 +/- 7% beta 2 in the control group. CONCLUSION: Cocaine use during pregnancy may be associated with a down-regulation of beta-adrenergic receptors in human myometrium. This could result in a decreased capacity for uterine relaxation and, consequently, a predisposition to preterm labor.

Adrenergic beta-Antagonists↗
PubMed1994

The location of abdominal wall blood vessels in relationship to abdominal landmarks apparent at laparoscopy.

OBJECTIVE: Our purpose was to evaluate the location of the major blood vessels of the abdominal wall relative to landmarks apparent at laparoscopy. STUDY DESIGN: Abdominal computed tomographic images of 21 reproductive-aged women at an academic center were retrospectively reviewed to determine the location of the inferior epigastric, superficial epigastric, and superficial circumflex iliac arteries and the lateral rectus muscle margins in relation to the symphysis pubis, the umbilicus, and the abdominal midline. These locations were correlated with each other and with body mass index using Pearson's correlation coefficient. RESULTS: Above the symphysis the inferior and superficial epigastric arteries were 5.6 +/- 1.0 cm (mean +/- SD) and 5.5 +/- 2.0 cm from the midline, respectively. Although the location of these two vessels correlated (r = 0.6, p = 0.02), the mean difference in their location was 1.4 +/- 1.1 cm. Near the level of the umbilicus the superficial epigastric and circumflex iliac arteries and the lateral rectus muscle margin were 4.6 +/- 1.4 cm, 10.7 +/- 1.7 cm, and 7.6 +/- 1.5 from the midline, respectively. Only the lateral rectus muscle margin correlated with body mass index (r = 0.65, p = 0.004). CONCLUSION: When laparoscopic landmarks are not visible to guide placement, lateral trocars should be placed approximately 8 cm from the midline and at least 5 cm above the symphysis to minimize the risk of vessel injury.

Abdominal Muscles↗
PubMed1994

Urologic laparoscopy with a new blunt-tipped trocar: safe, rapid access without the use of fascial sutures.

Fifteen patients underwent successful laparoscopic procedures where a new blunt-tipped trocar was used both to gain initial access to and to insufflate the abdominal cavity. The use of this new trocar obviates the need for the use of the Veress needle and appears to be both time-saving and possibly safer. Unlike the Hasson-type trocar, the blunt trocar technique does not require the use of fascial sutures for prevention of air leaks.

Adolescent↗
PubMed1994

A gestational-age-independent model of birth weight based on placental size.

A placental weight (P) to birth weight (W) relationship, W = P1.5 x constant (A), was presented in 1966. However, based on histological and theoretical studies, placental efficiency increases proportionally to the square of the gestational age in weeks. The purpose of this study was to develop and validate a gestational-age-independent model of birth weight based on P2. Data were prospectively entered into a computerized database for liveborn, structurally normal neonates at a tertiary, urban center. 29,989 neonates had gestational ages based on menstrual dating, ultrasound and Ballard examination, 81.4% were African American. The 'best fit' of W = A x P1.5 had errors in predicting the mean birth weight by at least 10% from 24 to 33 weeks of gestation. In contrast, there was significant improvement (p < 0.05) when the model W = 0.0071 x P2 was used; errors of greater than 10% only occurred at 28 and 43 weeks of gestation. This model had similar accuracy when stratified according to gender or ethnicity. A gestational-age-independent model of mean birth weight can be based upon the square of placental weight. We hypothesize that this model may have utility in understanding disorders of intrauterine fetal growth.

Birth Weight↗