Transitions in morphology, nematocyst distribution, fluid motions, and prey capture during development of the scyphomedusa Cyanea capillata.

Like that of most scyphozoans, the ontogeny of Cyanea capillata medusae involves substantive alterations in feeding structures and mechanics. We used video and optical microscopy approaches to quantify these ontogenetic changes in morphology, flow, and feeding of C. capillata medusae. We found that alterations in gross morphology and nematocyst distributions coincided with a shift from prey capture on the manubrium or lappets of ephyrae (bell diameter 0.2-0.4 cm) to capture primarily on the tentacles in adult medusae (diameter >1.0 cm). These changes occurred within a hydrodynamic framework that itself changed due to medusan growth. Viscous forces were important in flows around small ephyrae (maximum Re <10(1)), whereas viscosity was less influential in the inertially dominated flows around adult medusae (Re > 10(2)). The relative timing of these events indicates that ontogenetic processes are closely synchronized with alterations in the hydrodynamic environment within which C. capillata medusae develop.

Experience with routine voluntary perinatal human immunodeficiency virus testing in an inner city hospital.

Women enrolled in prenatal care at Grady Health System, Atlanta, GA, have routinely been offered HIV counseling and voluntary testing since 1987. Consistently >90% have accepted testing. With implementation of US Public Health Service guidelines for perinatal zidovudine prophylaxis in 1994, the mother-to-child HIV transmission rate rapidly decreased from 18% to 8% during the subsequent 2 years.

Violence in A&E departments: a systematic review of the literature.

Violence against A&E staff is increasing, and national initiatives have been implemented to counter the threat to staff. The aim of this paper is to determine the risks to staff of working in A&E and to determine methods of risk-reduction, using searches of literature and web-based resources. There is also critical appraisal of the data therein.

Comparison of Alora estradiol matrix transdermal delivery system with oral conjugated equine estrogen therapy in relieving menopausal symptoms. Alora Study Group.

OBJECTIVE: To compare the efficacy of two strengths of an estradiol matrix transdermal delivery system with daily oral doses of conjugated equine estrogens in reducing the frequency of moderate-to-severe hot flushes in postmenopausal women. DESIGN: The design of the study provided for the following treatment regimens: an estradiol transdermal delivery system (Alora 0.05 or 0.1 mg/day) administered twice weekly or oral doses of conjugated equine estrogens (CEE 0.625 or 1.25 mg) administered daily were given to 321 highly symptomatic postmenopausal women for 12 weeks following a randomized, parallel-group, double-blind, double-dummy design. RESULTS: Results indicate no statistically significant differences at any time point in mean frequency or mean percentage reduction in frequency of moderate-to-severe hot flushes between patients given Alora 0.1 mg/day and those receiving CEE 1.25 mg/day. Similarly, no significant differences were observed at any time in mean frequency of moderate-to-severe hot flushes between the Alora 0.05 mg/day and CEE 0.625 mg/day groups, although the group receiving CEE 0.625 mg/day exhibited a statistically greater percentage reduction than the Alora 0.05 mg/day group at weeks 3, 4 and 8. By week 12, these two treatments were statistically indistinguishable. There were no serious or unexpected adverse events with the two transdermal systems and local skin tolerability was excellent. Other estrogenic effects such as restoration of vaginal cytology, breast tenderness and unexpected vaginal bleeding were comparable between transdermal and oral administration groups except for a lower incidence of bleeding in those women receiving the lower dose transdermal regimen.

Relation between single tomographic intravascular ultrasound image parameters and intracoronary Doppler flow velocity in patients with intermediately severe coronary stenoses.

BACKGROUND: Intravascular ultrasound (IVUS) imaging parameters have been suggested as criteria to determine coronary lesion significance before intervention. However, there has not been a systematic examination of combined anatomic and physiologic data in the same patients with coronary artery disease. METHODS AND RESULTS: To examine the relation between coronary flow reserve and IVUS parameters, 41 patients with intermediately severe coronary artery stenoses had measurements of coronary flow velocity (0.014-inch Doppler flow wire), coronary flow velocity reserve (CVR) (hyperemic/basal mean flow), IVUS imaging (2.9F, Cardiovascular Imaging Systems, Inc.), and quantitative coronary angiography before intervention. Correlations between physiologic and anatomic parameters were performed by simple regression. Results were also examined by patient subgroups with CVR > 1.8 or < 1.8 to assess differences in IVUS parameters. The angiographic percent diameter stenosis was 52% +/- 17% (range 18% to 95%). Mean CVR was 1.88 +/- 0.56 (range 0.9 to 3.18). IVUS minimal luminal diameter (r = 0.312, p = 0.047) and angiographic percent stenosis (r = 3.05, p = 0.052) were weakly related to poststenotic CVR. Comparing patients with CVR < 1.8, IVUS reference segment area, IVUS lumen area, and angiographic percent diameter stenosis was higher (17.7 +/- 0.3 vs 12.9 +/- 4.4 mm2, p < 0.05; 6.20 +/- 3.76 vs 4.34 +/- 2.00 mm2, p < 0.05; and 60% +/- 14% vs 46% +/- 17%, p < 0.01, respectively) than in the group with CVR > 1.8. CONCLUSIONS: Despite a precise determination of cross-sectional vessel areas and absolute dimensions by IVUS, single tomographic measurements did not correlate well with coronary physiologic responses. These data suggest that the physiologic data may be complementary to anatomic quantitative IVUS, enhancing information for coronary interventional decision making.

Double-masked, multicenter study of an estradiol matrix transdermal delivery system (Alora) versus placebo in postmenopausal women experiencing menopausal symptoms. Alora Study Group.

This 12-week, double-masked, double-dummy, randomized, parallel-group study compared the efficacy and safety of an estradiol matrix transdermal delivery system (Alora) in two strengths (50-microgram/d estradiol and 100-microgram/d estradiol) with placebo in postmenopausal women who were experiencing at least 60 moderate-to-severe hot flushes per week. In 273 postmenopausal women, the reduction in the frequency of moderate-to-severe hot flushes was significantly better than placebo within 2 weeks of initiating therapy in the 100-microgram/d group and within 3 weeks of initiating therapy in the 50-microgram/d group. The reduction in hot flushes for both active treatment groups remained significantly different from placebo throughout the 12-week trial. Improvement in vaginal cytology profile (maturation index) was observed in both active treatment groups. Serum estradiol concentrations were elevated to early-to mid-follicular levels, in proportion to dose, and the estradiol/estrone ratio remained within the expected premenopausal range. The incidence of estrogen-related side effects was modest but greater in the active treatment groups than in the placebo group: Breast pain was reported in 4.5% of the patients in the 50-microgram/d group, 5.3% of patients in the 100-microgram/d group, and none of the patients in the placebo group. Breakthrough bleeding occurred in 3.4% of women in the 50-microgram/d group, 20.2% of women in the 100-microgram/d group, and 4.4% of women in the placebo group. Only 3 (1.1%) patients terminated treatment because of skin reactions. This study demonstrates that this estradiol matrix transdermal delivery system is effective in the treatment of menopausal symptoms, while providing the skin tolerability desired by patients.

The effect of desogestrel, gestodene, and other factors on spotting and bleeding.

Spotting and bleeding are among the most common side effects associated with oral contraceptive (OC) use and their occurrence is a prime determinant of whether a new user will continue to use OCs. Desogestrel and gestodene are two new progestins that were developed in part to minimize the occurrence of these side effects. Assessing the effect of these progestins is difficult, however, in part because their effects may be subtle, requiring a large sample size and possibly being overshadowed by other factors. To address these issues, we analyzed data from two comparative multicenter clinical trials that included 15,421 cycles among 2767 women. One study compared 75 micrograms gestodene + 30 micrograms ethinyl estradiol (EE) with 150 micrograms desogestrel + 30 micrograms EE, the other compared the same gestodene preparation with 150 micrograms desogestrel + 20 micrograms EE. Both studies found a higher risk of spotting or bleeding in all cycles among users of the desogestrel-containing preparation, with the differences ranging between 20% and 70% higher for the first study and 40% and 140% in the second. These differences were statistically significant in four of six cycles in each study and persisted after controlling for consistency and recency of OC use as well as smoking. After pooling the data and controlling for estrogen dose, the desogestrel-containing preparation was significantly associated with more frequent spotting or bleeding in five of six cycles. Smoking and consistency and recency of OC use were also independent predictors of spotting or bleeding.

Vasectomy and cardiovascular deaths in Korean men: a community-based case-control study.

This community-based case-control study was carried out in four cities in South Korea to examine whether vasectomy is associated with a long-term increased risk of cardiovascular death in Korean men. Our results coincide with those from epidemiological studies conducted in Western countries as well as the one study conducted in China and do not support the vasectomy--atherosclerosis hypothesis originating from animal research.

PIP: Researchers compared data on 413 35-65 year old men who died between October 1982-September 1983 with data on 413 healthy 35-65 year old men. Both cases and controls were from Seoul, Pusan, or Incheon, South Korea. Interviewers spoke only to wives as proxies of the deceased. 36 cases and 26 controls had undergone a vasectomy, but none of their counterparts had undergone a vasectomy. This paired analysis revealed a statistically nonsignificant odds ratio (OR) of 1.38. The researchers then controlled for all confounding variables while conducting a multivariate analysis. They found the adjusted OR to be 1 for vasectomy. None of the 3 underlying causes of death ORs (cerebrovascular disease, ischemic heart disease, and hypertensive disease) different significantly from unity. The leading cause of death was stroke (71.4%). Just 7% died from ischemic heart disease. Limitations of the study included problematic diagnosis of underlying causes of death, heterogeneous cardiovascular deaths, and the lack of distinction between thrombotic or hemorrhagic stroke, and small number of cases when stratified by length of exposure to vasectomy or by cause of death. Nevertheless, like other epidemiologic studies, this community-based study did not find an association between cardiovascular deaths and vasectomy, even though animal research in the late 1970s-early 1980s found that vasectomy in monkeys brought on a progression of atherosclerosis.

The effects of a progestin-only oral contraceptive (levonorgestrel 0.03 mg) on breast-feeding.

This study was a non-randomized clinical trial which compared the breast-feeding experience of 250 Argentine women taking levonorgestrel 0.03 mg daily (begun one week after delivery) with that of 250 women using non-hormonal contraceptives. Weight gain of unsupplemented infants, the most important of the several criteria used to assess breast-feeding performance, was similar for the two contraceptive groups. Levonorgestrel users began supplementary feeding of their infants significantly later than did non-hormonal users; levonorgestrel users were also somewhat less likely to discontinue breast-feeding during the study period. The two contraceptive groups were similar with regard to several other measures of breast-feeding performance: growth of all infants (regardless of supplementation), patterns of contraceptive discontinuation, mothers' subjective impressions of breast-milk sufficiency, and comparison of supplementation initiation with previous experience.

PIP: This study was a non-randomized clinical trial which compared the breast-feeding experience of 250 Argentine women taking levonorgestrel 0.03mg daily (begun one week after delivery) with that of 250 women using non-hormonal contraceptives. Weight gain of unsupplemented infants, the most important of the several criteria used to assess breast-feeding performance, was similar for the 2 contraceptive groups. Levonorgestrel users began supplementary feeding of their infants significantly later than did non-hormonal users; levonorgestrel users were also somewhat less likely to discontinue breast-feeding during the study period. The 2 contraceptive groups were similar with regard to several other measures of breast-feeding performance; growth of all infants (regardless of supplementation), patterns of contraceptive discontinuation, mothers' subjective impressions of breast-milk sufficiency, and comparison of supplementation initiation with previous experience.

Effect of the contraceptive sponge on chlamydial infection, gonorrhea, and candidiasis. A comparative clinical trial.

To investigate the effect of the nonoxynol 9-impregnated contraceptive sponge on the incidence of chlamydial infection, gonorrhea, and candidiasis, we conducted a randomized comparative study among high-risk women in Bangkok, Thailand. The first (parallel) portion of the study covered 434 woman-weeks among sponge users and 494 woman-weeks among nonusers. As compared with women not using the sponge, sponge users were found to be less likely to become infected with chlamydia (relative rate, 0.67; 95% confidence interval, 0.42 to 1.07) and gonorrhea (relative rate, 0.31 [0.16 to 0.60]) but more likely to become infected with Candida (relative rate, 2.76 [0.96 to 7.98]). Women who continued in the study were crossed over to the alternate group, with former nonusers starting to employ the sponge and vice versa. The results of this second phase were similar to those of the larger parallel study. Overall, these results suggest that women using the sponge are protected against the two most common sexually transmitted pathogens, which are also those with the most serious health consequences. However, women using the sponge should be advised they may have an increased likelihood of a vaginal infection with Candida.

[Vasectomy and cardiovascular deaths in Korean men].

PIP: This community-based case-control study was carried out in 4 cities in South Korea to investigate whether vasectomy is associated with a long-term increased risk of cardiovascular death. The cases are 413 men who died at ages 35-65 between October 1982 and September 1983 with an underlying cause of death, as reported in the death certificate, of ischemic heart disease (29 men), nontraumatic cerebrovascular disease (295 men), or hypertensive disease (89 men). Each case was matched for age and parity to a living male from the same neighborhood. Wives of cases and controls were interviewed at home as surrogates. Univariate analysis of the association between vasectomy and cardiovascular death revealed an odds ration of 1.4. Multivariate logistic regression analysis, controlling for potentially confounding variables, revealed a lower adjusted odds ratio of 1. The authors did not detect an association between vasectomy and cardiovascular death in Korean men; nor did they find a statistically significant increased risk for those subjects who had a vasectomy 15 years or more previously. These results concur with those from Western epidemiologic studies and do not support the vasectomy-atherosclerosis hypothesis originating from animal research.^ieng

Parity and use-effectiveness with the contraceptive sponge.

The results of a randomized United States study indicated that the Today contraceptive sponge was less effective than the diaphragm (1-year cumulative life-table rate of 17.4 versus 12.9 pregnancies per 100 women, p = 0.01). However, this overall comparison is misleading. Using univariate and multivariate analyses to account for the effects of user characteristics we found parity to be the most important single determinant of effectiveness for users of the sponge, but parity was unimportant as a risk factor for pregnancy among diaphragm users. For nulliparous women the sponge was as effective as a physician-prescribed barrier method (13.9 for sponge, 12.8 for diaphragm, p = 0.45); however, parous women using the sponge were twice as likely to become pregnant (28.3 for sponge, 13.4 for diaphragm, p = 0.001). The effect of parity among sponge users is consistent with the results of international studies of the contraceptive sponge.

Delivery type and neonatal mortality among 10,749 breeches.

Data on 10,749 breech presentations were analyzed for the effect of delivery type on neonatal mortality. Most of the data are from developing countries, and most of the hospitals have higher mortality than is found in Europe or the United States. The simultaneous effect of type of hospital where the delivery occurred, type of breech, birthweight, and parity were examined. The benefit of cesarean delivery was greater for nulliparae than multiparae, greater for footlings than for frank or complete breeches, and greater for larger babies than smaller ones. This last finding probably reflects the quality of neonatal care in developing country hospitals rather than the value of cesarean section. Maternal mortality and morbidity was higher among women delivered abdominally than among those delivered vaginally.

Hospitalizations among black women using contraceptives.

We analyzed hospitalizations among 26,507 young black women who attended a large metropolitan family planning clinic between 1968 and 1976. Age-adjusted hospitalization rates were compared for women using oral contraceptives, intrauterine contraceptive devices, and depot medroxyprogesterone acetate. Overall, intrauterine contraceptive device and depot medroxyprogesterone acetate users were hospitalized at about the same rate, while women using oral contraceptives were hospitalized 30% less often. The oral contraceptive users were not hospitalized at a higher rate for circulatory disease. Compared to women using intrauterine contraceptive devices, users of oral contraceptives and depot medroxyprogesterone acetate were less likely to be hospitalized for benign breast disease (rate ratios = 0.5 and 0.2, respectively, with 95% confidence limits of 0.3 to 0.7 and 0.1 to 0.5) and for pelvic inflammatory disease. Women were four times as likely to be using depot medroxyprogesterone acetate when they were hospitalized with carcinoma in situ of the cervix, but depot medroxyprogesterone acetate users with at least 3 years of use were less likely to be hospitalized for carcinoma in situ than comparable groups of oral contraceptive and intrauterine contraceptive device users.

Statistical comparison of Pearl rates.

Statistical procedures for hypothesis testing and interval estimation of the difference in a pair of Pearl rates are presented. The p value of the test statistic is evaluated exactly from the binomial distribution or approximately from the standard normal distribution. Interval estimation is provided by the test-based method of Miettinen. The procedures are applied to two published data sets, and the conceptual link between the Pearl rate and life-table methods is discussed.

Sterilization in the northeast of Brazil.

Results of household surveys carried out in four states in the Northeast of Brazil showed that female sterilization is the most prevalent method among women who want no more children. Many women who indicated an interest in tubal ligation, however, had not been sterilized. Access to sterilization depends on the type of hospital in which the child was delivered and the type of delivery the woman had. Over 60% of the sterilized women reported that they had a tubal ligation at the time they were hospitalized for a cesarean delivery. Compared with unsterilized women, the sterilized women are characterized by relatively higher education levels and a greater likelihood of urban residence and were far more likely to have had cesarean deliveries and, therefore, to have qualified for postpartum sterilization on medical grounds.

Early symptoms and discontinuation among users of oral contraceptives in Sri Lanka.

The relationship between symptoms reported during the first two cycles of oral contraceptive use and subsequent discontinuation was studied using data from a comparative clinical trial of two oral contraceptives (standard dose and low dose) in Sri Lanka. Among 24 symptoms considered, the most commonly reported were headache, nausea, irritability, dizziness, tiredness, intermenstrual spotting/bleeding, backache, abdominal pain, vomiting, and hair loss. Headache, nausea, vomiting, and dizziness were closely associated with each other and strongly predictive of discontinuation for both drugs. No other symptoms were consistently associated with each other or with subsequent discontinuation. Intermenstrual spotting/bleeding was associated with later discontinuation of the standard dose preparation, but not the lower dose preparation.

Effects of breastfeeding on IUD performance.

The effect that lactation might have on intrauterine device (IUD) performance was investigated by using data from a series of multicenter clinical trials. Life-table methods were applied to compare breastfeeding and non-breastfeeding women with respect to IUD expulsion, accidental pregnancy, IUD removal for various reasons, and overall continuation of IUD use. Results indicate that breastfeeding does not increase the risk of expulsion or other events, whether the device is inserted immediately (within ten minutes) or more than 42 days after delivery. (Am J Public Health 1983; 73:384-388.)