Induction of thioredoxin and thioredoxin reductase gene expression in lungs of newborn primates by oxygen. (1/1464)

Thioredoxin (TRX) is a potent protein disulfide oxidoreductase important in antioxidant defense and regulation of cell growth and signal transduction processes, among them the production of nitric oxide. We report that lung TRX and its reductase, TR, are specifically upregulated at birth by O2. Throughout the third trimester, mRNAs for TRX and TR were expressed constitutively at low levels in fetal baboon lungs. However, after premature birth (125 or 140 of 185 days gestation), lung TRX and TR mRNAs increased rapidly with the onset of O2 or air breathing. Lung TRX mRNA also increased in lungs of term newborns with air breathing. Premature animals (140 days) breathing 100% O2 develop chronic lung disease within 7-14 days. These animals had greater TRX and TR mRNAs after 1, 6, or 10 days of life than fetal control animals. In 140-day animals given lesser O2 concentrations (as needed) who do not develop chronic lung disease, lung TRX and TR mRNAs were also increased on days 1 and 6 but not significantly on day 10. In fetal distal lung explant culture, mRNAs for TRX and TR were elevated within 4 h in 95% O2 relative to 1% O2, and the response was similar at various gestations. In contrast, TRX protein did not increase in lung explants from premature animals (125 or 140 days) but did in those from near-term (175-day) fetal baboons after exposure to hyperoxia. However, lung TRX protein and activity, as well as TR activity, eventually did increase in vivo in response to hyperoxia (6 days). Increases in TRX and TR mRNAs in response to 95% O2 also were observed in adult baboon lung explants. When TRX redox status was determined, increased O2 tension shifted TRX to its oxidized form. Treatment of lung explants with actinomycin D inhibited TRX and TR mRNA increases in 95% O2, indicating transcriptional regulation by O2. The acute increase in gene expression for both TRX and TR in response to O2 suggests an important role for these proteins during the transition from relatively anaerobic fetal life to O2 breathing at birth.  (+info)

Mediators of ethnic-associated differences in infant birth weight. (2/1464)

PURPOSE: To examine whether ethnic differences in low birth weight babies of low-income women may be explained in part by group differences in prenatal health behaviors and psychosocial factors. METHODS: A prospective, survey of 1,071 low-income, primiparous African-American and Mexican-origin women was conducted in Los Angeles County, California. In face-to-face interviews, data were obtained on substance use, prenatal stress, social support, attitudes toward pregnancy, initiation of prenatal care, and medical risk. Medical chart data were abstracted regarding medical risk factors and labor, delivery, and neonatal data. Interview data were linked with birth outcome data retrieved from maternal medical records. Structural equation modeling was used to test a hypothesized model in which differences in birth weight were expected to be mediated by ethnic differences in substance use, psychosocial factors, and medical risk. RESULTS: As expected, African-American women delivered babies of earlier gestational age and lower birth weight than did women of Mexican origin. Direct predictors of low birth weight were use of drugs and cigarettes, prenatal stress, and positive attitudes toward pregnancy; together, these factors accounted for the observed ethnic differences in birth weight. CONCLUSION: These data contribute to our understanding of the factors that may account for ethnic-associated differences in low birth weight.  (+info)

The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1--a meta-analysis of 15 prospective cohort studies. The International Perinatal HIV Group. (3/1464)

BACKGROUND: To evaluate the relation between elective cesarean section and vertical transmission of human immunodeficiency virus type 1 (HIV-1), we performed a meta-analysis using data on individual patients from 15 prospective cohort studies. METHODS: North American and European studies of at least 100 mother-child pairs were included in the meta-analysis. Uniform definitions of modes of delivery were used. Elective cesarean sections were defined as those performed before onset of labor and rupture of membranes. Multivariate logistic-regression analysis was used to adjust for other factors known to be associated with vertical transmission. RESULTS: The primary analysis included data on 8533 mother-child pairs. After adjustment for receipt of antiretroviral therapy, maternal stage of disease, and infant birth weight, the likelihood of vertical transmission of HIV-1 was decreased by approximately 50 percent with elective cesarean section, as compared with other modes of delivery (adjusted odds ratio, 0.43; 95 percent confidence interval, 0.33 to 0.56). The results were similar when the study population was limited to those with rupture of membranes shortly before delivery. The likelihood of transmission was reduced by approximately 87 percent with both elective cesarean section and receipt of antiretroviral therapy during the prenatal, intrapartum, and neonatal periods, as compared with other modes of delivery and the absence of therapy (adjusted odds ratio, 0.13; 95 percent confidence interval, 0.09 to 0.19). Among mother-child pairs receiving antiretroviral therapy during the prenatal, intrapartum, and neonatal periods, rates of vertical transmission were 2.0 percent among the 196 mothers who underwent elective cesarean section and 7.3 percent among the 1255 mothers with other modes of delivery. CONCLUSIONS: The results of this meta-analysis suggest that elective cesarean section reduces the risk of transmission of HIV-1 from mother to child independently of the effects of treatment with zidovudine.  (+info)

Birth of a healthy neonate following the intracytoplasmic injection of testicular spermatozoa from a patient with Klinefelter's syndrome. (4/1464)

Klinefelter's syndrome is one of the known causes of azoospermia or cryptoazoospermia, and it may present in non-mosaic (47,XXY) or mosaic (47,XXY/46,XY) form. The likelihood of finding spermatozoa in the ejaculate or testicular tissue of patients with mosaic Klinefelter's syndrome is low, and with the non-mosaic form, even lower. We describe a patient with non-mosaic Klinefelter in whom initially non-motile spermatozoa were derived from searching the ejaculate. Ten mature oocytes were injected, but none was fertilized. Subsequently, testicular biopsy was undertaken in order to collect spermatozoa for oocyte injection. Fifteen motile sperm cells were found and injected. Nine oocytes were fertilized and cleaved; three embryos were transferred into the uterine cavity. The woman conceived and following a normal pregnancy delivered a healthy child. Genetic analysis of the neonate disclosed a normal 46,XY karyotype. Non-motile spermatozoa in the ejaculate did not prove their fertilization potential, but their presence did not exclude finding motile, fertile spermatozoa in the testicular tissue in a non-mosaic Klinefelter patient. This report is further evidence that normal spermatozoa with fertilization potential are produced in the testes of patients with Klinefelter's syndrome.  (+info)

Programming for safe motherhood: a guide to action. (5/1464)

The Safe Motherhood Initiative has successfully stimulated much interest in reducing maternal mortality. To accelerate programme implementation, this paper reviews lessons learned from the experience of industrial countries and from demonstration projects in developing countries, and proposes intervention strategies of policy dialogue, improved services and behavioural change. A typological approach with three hypothetical settings from resource poor to resource rich environments is used to address the variability in health behaviours and infrastructure encountered when programming for safe motherhood.  (+info)

The development and implementation of normal vaginal delivery clinical pathways in a large multihospital health system. (6/1464)

The entire country has become more concerned with healthcare costs due to managed care, capitation risk-based contracts, and the near elimination of the cost-plus reimbursement system. Clinical pathways have become one way to reduce unnecessary resource consumption by reducing provider variance, improving clinical outcomes, and reducing cost. We present here our rationale and process for developing a common clinical pathway for normal vaginal delivery in a large and varied multihospital system. We also discuss how this new pathway is expected to improve quality of care and reduce costs.  (+info)

Method of linking Medicaid records to birth certificates may affect infant outcome statistics. (7/1464)

OBJECTIVES: This study assessed how different methods of matching Medicaid records to birth certificates affect Medicaid infant outcome statistics. METHODS: Claims paid by Medicaid for hospitalization of the newborn and for the mother's delivery were matched separately to 1995 North Carolina live birth certificates. RESULTS: Infant mortality and low-birthweight rates were consistently lower when Medicaid was defined by a matching newborn hospitalization record than when results were based on a matching Medicaid delivery record. CONCLUSIONS: Studies of birth outcomes in the Medicaid population may have variable results depending on the method of matching that is used to identify Medicaid births.  (+info)

Neonatal outcome and mode of delivery after epidural analgesia for labour with ropivacaine and bupivacaine: a prospective meta-analysis. (8/1464)

In this prospective meta-analysis, we have evaluated the effect of epidural analgesia with ropivacaine for pain in labour on neonatal outcome and mode of delivery compared with bupivacaine. In six randomized, double-blind studies, 403 labouring women, primigravidae and multiparae, received epidural analgesia with ropivacaine or bupivacaine 2.5 mg ml-1. The drugs were administered as intermittent boluses in four studies and by continuous infusion in two. Apgar scores, neurological and adaptive capacity scores (NACS), degree of motor block and mode of delivery were recorded. The studies were designed prospectively to fit meta-analysis of the pooled results. Results showed similar pain relief and consumption of the two drugs. In the vaginally delivered neonates, NACS scores were approximately equal for both groups at 2 h, but at 24 h there were fewer infants with NACS less than 35 in the ropivacaine compared with the bupivacaine group (2.8% vs 7.6%; P < 0.05). Spontaneous vaginal deliveries occurred more frequently overall with ropivacaine than with bupivacaine (58% vs 49%; P < 0.05) and instrumental deliveries (forceps and vacuum extraction) less frequently (27% vs 40%; P < 0.01), while the frequency of Caesarean section was similar between groups. The intensity of motor block was lower with ropivacaine. There were no significant differences in adverse events.  (+info)