Fruit bats (Pteropodidae) fuel their metabolism rapidly and directly with exogenous sugars.

Previous studies reported that fed bats and birds mostly use recently acquired exogenous nutrients as fuel for flight, rather than endogenous fuels, such as lipids or glycogen. However, this pattern of fuel use may be a simple size-related phenomenon because, to date, only small birds and bats have been studied with respect to the origin of metabolized fuel, and because small animals carry relatively small energy reserves, considering their high mass-specific metabolic rate. We hypothesized that approximately 150 g Egyptian fruit bats (Rousettus aegyptiacus Pteropodidae), which are more than an order of magnitude heavier than previously studied bats, also catabolize dietary sugars directly and exclusively to fuel both rest and flight metabolism. We based our expectation on the observation that these animals rapidly transport ingested dietary sugars, which are absorbed via passive paracellular pathways in the intestine, to organs of high energy demand. We used the stable carbon isotope ratio in exhaled CO(2) (delta(13)C(breath)) to assess the origin of metabolized substrates in 16 Egyptian fruit bats that were maintained on a diet of C3 plants before experiments. First, we predicted that in resting bats delta(13)C(breath) remains constant when bats ingest C3 sucrose, but increases and converges on the dietary isotopic signature when C4 sucrose and C4 glucose are ingested. Second, if flying fruit bats use exogenous nutrients exclusively to fuel flight, we predicted that delta(13)C(breath) of flying bats would converge on the isotopic signature of the C4 sucrose they were fed. Both resting and flying Egyptian fruit bats, indeed, directly fuelled their metabolism with freshly ingested exogenous substrates. The rate at which the fruit bats oxidized dietary sugars was as fast as in 10 g nectar-feeding bats and 5 g hummingbirds. Our results support the notion that flying bats, irrespective of their size, catabolize dietary sugars directly, and possibly exclusively, to fuel flight.

Experience and covariates of depressive symptoms among a cohort of HIV infected women.

OBJECTIVES: The objectives of this study are to assess (a) the level of depressive symptoms among a cohort of HIV infected women and comparable controls and (b) the relationship with covariates including socioeconomic status, substance use, social relations, disease status. METHODS: Participants were enrolled in the Women's Interagency HIV Study (WIHS). Depressive symptoms were measured using the Center for Epidemiological Studies Depression Scale (CESD). Data from 1993 HIV seropositive and 551 seronegative women are presented. RESULTS: Of HIV positive women 57.7% of HIV positive women scored 16 or higher on the CESD (ns) as compared to 55.0% of HIV negative women; at a cutoff of 23, the percents were 40.4% and 35.9% respectively (p = .06). The mean score was high 19.8 but not significantly different between groups. Scores were higher among women who had less education, lower income, were of Hispanic ethnicity, used alcohol or drugs, experienced domestic abuse, had more than one partner, or had less supportive relationships. Among infected women, higher CESD scores were not significantly associated with CD4 cell count but were elevated for self-reported Class C AIDS defining clinical conditions. CONCLUSIONS: The scores on the CESD were elevated for both HIV positive and HIV negative women and the differences between the groups were small. Lower socioeconomic status and social support and higher substance use and domestic abuse were associated with depressive symptoms similarly for both groups.

Domestic violence and childhood sexual abuse in HIV-infected women and women at risk for HIV.

OBJECTIVES: The purpose of this study was to determine the prevalence and effect of domestic violence and childhood sexual abuse in women with HIV or at risk for HIV infection. METHODS: Participants with HIV or at risk for HIV infection enrolled in the Women's Interagency HIV Study. Childhood sexual abuse; all physical, sexual, and coercive violence by a partner; HIV serostatus; demographic data; and substance use and sexual habits were assessed. RESULTS: The lifetime prevalence of domestic violence was 66% and 67%, respectively, in 1288 women with HIV and 357 uninfected women. One quarter of the women reported recent abuse, and 31% of the HIV-seropositive women and 27% of the HIV-seronegative women reported childhood sexual abuse. Childhood sexual abuse was strongly associated with a lifetime history of domestic violence and high-risk behaviors, including using drugs, having more than 10 male sexual partners and having male partners at risk for HIV infection, and exchanging sex for drugs, money, or shelter. CONCLUSIONS: Our data support the hypothesis of a continuum of risk, with early childhood abuse leading to later domestic violence, which may increase the risk of behaviors leading to HIV infection.

Improved Count Rate and Resolution Performance of a Thermoelectrically Cooled Si(Li) X-ray Detector.

: A new energy-dispersive spectrometer Si(Li) detector for microanalysis applications, cooled by a thermoelectric (Peltier) refrigerator, was significantly improved with regard to the resolution and high count-rate performance. This new detector was mounted on a JEOL 6400 scanning electron microscope, and several application tests were run to analyze its performance. The common resolution test using an Fe55 radioactive source was performed, and it was compared with the conventional liquid nitrogen (LN) detector. The resolution at low and high count-rate was found to be slightly less than the LN detector's performance; however, these differences are minor and most application requirements were easily met. The thermoelectric cooling mechanism was found to be stable and reliable with no degradation in its performance recorded during several years of use. The collected data show improved performance by the new thermoelectrically cooled (TEC) detector compared with the old TEC design and underscore performance very close to the LN product. For most microanalysis applications, the new TEC X-ray detector can easily replace the LN detector and avoid the maintenance associated with LN filling.

Sexual, contraceptive, and drug use behaviors of women with HIV and those at high risk for infection: results from the Women's Interagency HIV Study.

OBJECTIVE: To document the sexual and contraceptive practices of women with HIV infection or who are at risk for infection. DESIGN: Data on the baseline behaviors of 561 HIV-negative and 2040 HIV-positive women were collected as part of the Women's Interagency HIV Study (WIHS). WIHS is a multisite, longitudinal study following the natural history of HIV infection among women in the United States. METHODS: Each participant contributed an interviewer administered, self-report interview including questions on sexual and contraceptive behavior. RESULTS: Women with HIV were less likely to report heterosexual activity in the previous 6 months (65% HIV-positive, 76% HIV-negative). Among sexually active women, there were no differences in the proportion of those reporting vaginal (97% HIV-positive, 98% HIV-negative) or anal sex (12% HIV-positive, 10% HIV-negative), although women with HIV were less likely to report cunnilingus (41% HIV-positive, 70% HIV-negative) and fellatio (48% HIV-positive, 57% HIV-negative). Of women with HIV, 63% always used condoms during vaginal sex (versus 28% HIV-negative), with lower rates reported during other sexual activities. Crack, cocaine, or injecting drug use, reported by 27% of HIV-positive and 35% of HIV-negative women, was associated with inconsistent condom use, independent of serostatus. HIV-positive women who reported using condoms and another contraception method were less consistent condom users (57% consistent versus 67%). CONCLUSIONS: The prevalence of sexual risk behavior in this sample suggests that, although women with HIV exhibit lower levels of sexual risk behavior than uninfected women, many have not been successfully reached with regard to implementing safer behaviors. These findings have implications for more widespread and effective behavioral intervention efforts.

Lower genital tract infections among HIV-infected and high-risk uninfected women: findings of the Women's Interagency HIV Study (WIHS).

BACKGROUND AND OBJECTIVES: Few comparisons of factors associated with sexually transmitted diseases (STDs) and HIV are available for representative samples of American women. GOAL OF THE STUDY: To compare factors associated with STDs in a large sample of women infected with HIV and women not infected with HIV. STUDY DESIGN: A cross-sectional analysis of STDs in 2,058 women seropositive (HIV+) for HIV and 567 women seronegative (HIV-) for HIV. RESULTS: HIV + women were more likely than HIV- women to report previous STDs, with the exceptions of chlamydia and bacterial vaginosis. Both HIV status and CD4 lymphocyte count were associated with evidence of genital ulcerations, warts, and vaginal candidiasis (p <0.001 for all). HIV- women were more apt to report recent vaginal intercourse (p <0.001), a factor that was independently associated with the occurrence of bacterial and protozoan infections. CD4 lymphocyte depletion was the factor most closely associated with the expression of chronic viral infections. CONCLUSIONS: In this North American cohort, HIV+ women were more likely than HIV- women to report previous genital tract infections and symptoms. However, the HIV+ women reported less recent sexual activity and few gonococcal or chlamydial infections.

The Women's Interagency HIV Study. WIHS Collaborative Study Group.

The Women's Interagency HIV Study comprises the largest U.S. cohort to date of human immunodeficiency virus (HIV)-seropositive women (N = 2,058) with a comparison cohort of seronegative women (N = 568). The methodology, training, and quality assurance activities employed are described. The study population, enrolled between October 1994 and November 1995 through six clinical consortia throughout the United States (totaling 23 sites) represents a typically hard-to-reach study population. More than half of the women in each cohort were living below the federally defined levels of poverty. The women ranged in age from 16 to 73 years; approximately one-quarter self-identified as Latina or Hispanic, over one-half as African-American not of Hispanic origin, and less than 20% as white, non-Hispanic origin. Self-reporting of HIV exposure risk included injection drug use by 34% of the seropositive women and 28% of the seronegative women, heterosexual contact (42% vs 26%), transfusion risk (4% vs 3%) and no identified risk (20% vs 43%). Demographic and HIV exposure risk characteristics of the seropositive cohort were comparable with characteristics of nationally reported AIDS cases in U.S. women. This well characterized cohort of HIV-seropositive and high-risk seronegative women represents a rich opportunity for future studies of HIV disease progression and pathogenesis.

Woman abuse and pediatrics: expanding the web of detection.

Efforts to increase the medical care system's responsiveness to victims of domestic violence have been focused on emergency and obstetric/gynecologic care. This paper advocates for expanding the web of detection to include pediatric practitioners. In order to effectively address the issue of domestic violence, medical providers must be linked to community-based resources. Physicians need to understand the complexity of this issue and focus on the process (empowerment) rather than on an outcome (leaving). A broader conceptualization of the battering situation, appropriate medical system response, and specific suggestions for how pediatric providers can inquire about and respond to domestic violence are provided.

Clinical determinants of the racial disparity in very low birth weight.

BACKGROUND: Although the risk of very low birth weight (less than 1500 g) is more than twice as high among blacks as among whites in the United States, the clinical conditions associated with this disparity remain poorly explored. METHODS AND RESULTS: We reviewed the medical records of over 98 percent of all infants weighing 500 to 1499 g who were born in Boston during the period 1980 through 1985 (687 infants), in St. Louis in 1985 and 1986 (397 infants), and in two health districts in Mississippi in 1984 and 1985 (215 infants). The medical records of the infants' mothers were also reviewed. These data were linked to birth-certificate files. During the study periods, there were 49,196 live births in Boston, 16,232 in St. Louis, and 16,332 in the Mississippi districts. The relative risk of very low birth weight among black infants as compared with white infants ranged from 2.3 to 3.2 in the three areas. The higher proportion of black infants with very low birth weights was related to an elevated risk in their mothers of major conditions associated with very low birth weight, primarily chorioamnionitis or premature rupture of the amniotic membrane (associated with 38.0 percent of the excess proportion of black infants with very low birth weights [95 percent confidence interval, 31.3 to 45.4 percent]); idiopathic preterm labor (20.9 percent of the excess [95 percent confidence interval, 16.0 to 26.4 percent]); hypertensive disorders (12.3 percent [95 percent confidence interval, 8.6 to 16.6]); and hemorrhage (9.8 percent [95 percent confidence interval, 5.5 to 13.5]). CONCLUSIONS: The higher proportion of black infants with very low birth weights is associated with a greater frequency of all major maternal conditions precipitating delivery among black women. Reductions in the disparity in birth weight between blacks and whites are not likely to result from any single clinical intervention but, rather, from comprehensive preventive strategies.

Delayed childbearing: no evidence for increased risk of low birth weight and preterm delivery.

Prior studies of the effect of increased maternal age on reproductive outcome in primiparous women have often ignored the possible influence on this relation of more frequent histories of spontaneous abortion and infertility in older women. When these histories are taken into account, the present study of 1,382 white primiparous women who had live singleton deliveries at Yale-New Haven Hospital finds no evidence for an increased risk of low birth weight (relative risk (RR) = 1.06, 95% confidence interval (CI) = 0.38-2.94) or preterm delivery (RR = 1.07, 95% CI = 0.50-2.24) in women delivering at age 30 years or more compared with younger women. Mean birth weight (beta = -19 g, p = 0.57) and gestational age (beta = -0.16 weeks, p = 0.34) were also not significantly affected by older maternal primiparity. Women aged 35 years or more had twice the rate of preterm births compared with women under age 30, although this result was not statistically significant in this data set (RR = 2.07, 95% CI = 0.67-6.35). Other confounding variables were taken into account.

Chiral separations of cationic and anionic drugs on an alpha 1-acid glycoprotein-bonded stationary phase (EnantioPac). II. Influence of mobile phase additives and pH on chiral resolution and retention.

The influence of mobile phase additives and pH on chiral resolution and retention on a high performance liquid chromatographic chiral stationary phase composed of alpha 1-acid glycoprotein bonded to diethylaminoethyl silica (EnantioPac) has been investigated. Cationic and anionic compounds of widely differing structures were chromatographed and drastic effects on stereoselectivity were observed with hydrophobic charged modifiers. For cationic solutes, a decrease in the pH of the mobile phase from 7.0 to 6.0 gave reduced retention and, in some cases, improved selectivity when tetrabutylammonium or tetrapropylammonium bromide was used as modifier. For anionic solutes, a pH decrease from 6.6 to 6.1 gave enhanced retention but without a significant change in stereoselectivity. The steric bulk and hydrophobic moieties of the solute seem to have a strong influence on chiral selectivity. Widely different separating efficiencies were obtained with molecules of different structures.

Column chromatographic analysis of barbiturates in their dosage forms. IV. Combinations with parabens.

The nature of the alkaline hydrolysis of some barbiturates in combinations with parabens (p-hydroxybenzoates) was studied with controlled variables, including temperature, viscosity, and concentrations of sodium hydroxide, barbiturate, and parabens. The kinetic studies showed that parabens could be completely hydrolyzed in strong base at 40 degrees C in 1 hr, while the barbiturate remained intact and was readily isolated by partition chromatography, Based on the theoretical results, a partition chromatographic procedure for butabarbital with parabens was devised. Standard recoveries averaged 100.7% with a standard deviation of 0.89. Kinetic data indicate that the hydrolysis of parabens could also be applied to analyze combinations with amo-, seco-, and pentobarbitals. Phenobarbital and parabens are readily separated by partition chromatographic methods without prior hydrolysis of the parabens. The low extraction constant for phenobarbital allowed its retention on a column against relatively strong solvents while the intact parabens are eluted. A slightly modified method was applied to the separation of phenobarbital from parabens. Standard recoveries average 99.9% with a standard deviation of 0.69.

Extraction and partition chromatography of tolbutamide as ion-pairs with quaternary ammonium cations.

The partition of tolbutamide (1-butyl-3-(p-tolylsulfonyl) urea) as ion-pairs with homologous tetraalkyl ammonium cations was studied. The determination of experimental extraction constants permitted quantitative calculation of distribution ratios, in agreement with theoretical relationships, over a continuous range of about one billion. The nature and the concentration of the counter-ion and solvent composition were the variables studied. Based on the theoretical results, a rapid partition chromatographic procedure was devised. A solution of tolbutamide sample in 10% aqueous tetraethyl ammonium hydroxide is incorporated in the system as the immobile phase in the partition column. A 1+1 mixture of chloroform and isooctane removes extraneous materials; then chloroform elutes the tolbutamide-tetraethyl ammonium ion-pair, which is converted to the free acid by passing the eluate through a phosphoric acid segment, and tolbutamide is determined spectrophotometrically without further treatment. Standard recoveries averaged 100.5+/-0.70%; commercial tablets assayed 100.5+/-0.85%.

Column chromatographic analysis of barbiturates in their dosage forms. II. secobarbital, amobarbital, and pentobarbital.

A general method for the analysis of barbiturates, using column parition chromatography, was extended to the assay of secobarbital, amobarbital, and pentobarbital. A solution of the barbiturate constitutes the immobile phase in the chromatographic system. It is eluted with ether-isooctane (1+9) and passed onto a K3PO4 column, which retains the barbiturate while extraneous materials are washed out. The barbiturate is removed from the column with etherisooctane (3+1), extracted from the eluate with NH3, and measured spectrophotometrically.