Corticosteroids after preterm premature rupture of membranes

A review of all relevant randomized controlled trials provides strong evidence that corticosteroid therapy causes a significant reduction in respiratory distress syndrome (RDS) in preterm babies overall. This reduction in RDS is accompanied by a reduced incidence of neonatal death, intraventricular hemorrhages, and necrotizing enterocolitis. These benefits are also seen in cases of PROM. Corticosteroid therapy in PROM is associated with a trend toward an increase in neonatal infection.

Delivery in an obstetric birth chair: a randomized controlled trial

OBJECTIVE

To determine whether nulliparae whose second stage of labour is conducted in an obstetric birth chair have a lower incidence of instrumental delivery than those using a conventional delivery bed.

DESIGN

Randomized controlled trial using sealed, opaque envelopes for allocation.

SETTING

Delivery ward in a busy teaching hospital.

PATIENTS

1250 nulliparae with a singleton live fetus with cephalic presentation, without epidural anaesthesia, who had achieved full dilatation.

INTERVENTION

Intention to conduct second and third stages of labour in either the Birth-EZ chair or the conventional delivery bed, as randomly allocated.

MAIN OUTCOME MEASURES

Primary measure: vaginal operative delivery; principal secondary measures: duration of second stage, perineal trauma, blood loss, women's views, and neonatal status.

RESULTS

Delivery in the birth chair did not result in a reduction in operative delivery, overall. However, there was a reduction in vaginal operative delivery for fetal heart rate abnormality. There was no beneficial effect on perineal trauma or puerperal perineal pain. Post-partum haemorrhage was more frequent in the birth chair group.

CONCLUSIONS

Delivery in the birth chair does not offer any obvious advantage to women over delivery on a bed.

Obstructive sleep apnea following topical oropharyngeal anesthesia in loud snorers

Previous studies support the presence of an upper airway reflex mechanism that contributes to the maintenance of upper airway patency during sleep. We investigated the possibility that interference with this reflex mechanism contributes to the development of obstructive sleep apnea. Eight otherwise asymptomatic snorers (seven male and one female), age 39 +/- 5.3 yr (mean +/- SEM), underwent overnight sleep studies on three successive nights. An acclimatization night was followed by two study nights randomly assigned to control (C) and oropharyngeal anesthesia (OPA). On the OPA night topical anesthesia was induced using 10% lidocaine spray and 0.25% bupivacaine gargle. A saline placebo was used on night C. All subjects slept well on both study nights (mean sleep duration was 6.2 h on both study nights), and sleep stage distribution was similar on both nights. Obstructive apneas and hypopneas (OAH) rose from 114 +/- 43 during C to 170 +/- 49 during OPA (p less than 0.02). Central apneas and hypopneas (CAH) were unchanged between the two nights (8 +/- 4.9 versus 7 +/- 3). The duration of OAH was similar on both study nights (20 +/- 1.9 s during C versus 20 +/- 1.5 s during OPA). The frequency of movement arousals terminating OAH tended to be higher during OPA (7 +/- 2.9/h) than during C (3 +/- 0.7); P = NS. The frequency of oxyhemoglobin desaturations was also higher during OPA (5 +/- 2.1/h) than during C (3 +/- 1.4), p less than 0.07.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel NADPH/NADH-dependent aldehyde reduction enzyme isolated from the tapeworm Moniezia expansa

An aldehyde reduction enzyme has been purified from the cytosol of the tapeworm, Moniezia expansa, by chromatofocusing and Reactive-Red chromatography. The enzyme is monomeric (subunit 34 kDa) and can utilise NADH and NADPH as co-factors. Substrates of the enzyme include alkanals, alka-2,4-dienals and alk-2-enals, established secondary products of lipid peroxidation. The enzyme reduced methylglyoxal, another possible natural substrate (M. expansa lacks glyoxalase I activity). The parasite enzyme may help form a final line of defence against cytotoxic aldehydes arising from host immune initiated lipid peroxidation.

Is intrauterine growth retardation with normal umbilical artery blood flow a benign condition?

OBJECTIVE

To determine whether intrauterine growth retardation associated with normal umbilical artery blood flow is a benign condition.

DESIGN

A prospective comparative study of growth retarded fetuses with normal and abnormal umbilical artery blood flow.

SETTING

The fetal assessment clinic of a large maternity hospital in Ireland.

PATIENTS

179 Women with singleton pregnancies in which the fetal abdominal circumference, measured by ultrasonography, was below the fifth centile for gestation.

MAIN OUTCOME MEASURES

Perinatal deaths, fetal distress requiring caesarean section, preterm delivery, cerebral irritation.

RESULTS

Of 124 fetuses with normal flow, all physically normal fetuses survived but one baby had cerebral irritation; there were six preterm deliveries and four caesarean sections for fetal distress. Among 55 women with abnormal flow there were two midtrimester abortions, three perinatal deaths, and one case of cerebral irritation in physically normal fetuses.

CONCLUSIONS

Intrauterine growth retardation associated with normal umbilical blood flow is a different entity from that associated with abnormal flow, normal flow being largely benign and abnormal flow carrying a serious risk of adverse outcome.

Relative distribution of glutathione transferase, glyoxalase I and glyoxalase II in helminths

Glutathione transferase, glyoxalase I and glyoxalase II activities were not evenly distributed among the major helminth groups. Intestinal cestodes and digeneans had higher glutathione transferase activity than parasitic nematodes. High glyoxalase II activity was found in cestodes and digeneans but no glyoxalase I was detectable. Glyoxalase I and II were both detected in nematodes. These results are discussed in relation to the enzymes' suggested role in protection against secondary lipid peroxidation products.

Detoxification reactions of Fasciola hepatica cytosolic glutathione transferases

Acidic/neutral glutathione (GSH) transferase forms have been isolated from Fasciola hepatica by a combination of GSH-affinity chromatography and chromatofocusing. Approximately 10-25% of the activity failed to interact with the GSH-affinity matrix when applied from crude cytosolic preparations. Following partial purification by chromatofocusing this GSH transferase activity did subsequently bind to the affinity matrix. The F. hepatica GSH transferases had catalytic activity with secondary lipid peroxidation products, the latter being possible natural substrates. The enzymes also interacted with a number of hydrophobic ligands including haematin and substituted phenol-based anthelmintics.

The effects of corticosteroid administration before preterm delivery: an overview of the evidence from controlled trials

Continuing differences of opinion among obstetricians and neonatologists about the place of corticosteroid administration before preterm delivery have prompted us to carry out a systematic review of the relevant controlled trials, using methods designed to minimize systematic and random error. Data from 12 controlled trials, involving over 3000 participants, show that corticosteroids reduce the occurrence of respiratory distress syndrome overall and in all the subgroups of trial participants that we examined. This reduction in respiratory morbidity was associated with reductions in the risk of intraventricular haemorrhage, necrotizing enterocolitis and neonatal death. There is no strong evidence suggesting adverse effects of corticosteroids. The risks of fetal and neonatal infection may be raised if they are administered after prolonged rupture of the membranes, but this possibility is not substantiated by the results of the available trials. The available data on long-term follow-up suggest that the short-term beneficial effects of corticosteroids may be reflected in reduced neurological morbidity in the longer term.

Neonatal seizures: the Dublin Collaborative Study

Asphyxial seizures occurred in 89 of 101,829 infants born alive at term (0.87/1000) in three large maternity hospitals from January 1980 to December 1984. These seizures were significantly associated with antenatal complications, primiparity, and prolonged pregnancy. Meconium staining of the amniotic fluid was also associated with asphyxial seizures, but there were high false positive (11%) and false negative (50%) rates. Fifteen of the infants who had seizures died (18%) and 21 (25%) were handicapped at 1 year. Outcome was most successfully predicted by the way the infant was feeding at 1-2 weeks. All infants taking more than half their estimated requirements by mouth at 1 week were normal, and those still being fed by tube at 2 weeks were handicapped.

Inhibition of growth of B16 melanoma by glucocorticoids does not result directly from receptor-mediated inhibition of tumour cells

The ability of dexamethasone (DM) to slow the growth of B16 melanoma in C57B1 mice was confirmed. Inhibition was dose-related and was demonstrated in the use of established tumours as well as initial transplants. Although glucocorticoid receptors (GR) were present in cultured tumour cells, DM did not reduce growth of B16 in vitro, even at high concentration. This dissociation of effect on growth in vivo and in vitro suggests that DM slows B16 tumour growth in vivo by mechanisms other than GR-mediated inhibition of tumour cells.

An E. coli-yeast shuttle cosmid with positive selection for inserted fragments

We describe the construction of a cosmid cloning vector, pMT555, which allows positive selection for the presence of an inserted DNA fragment. The vector contains sequences which enable its replication and selection in either E. coli or Saccharomyces cerevisiae. We demonstrate that pMT555 may be used for the efficient construction of total genomic banks from small quantities of donor DNA. The positive selection permits the stable maintenance of the cosmid in E. coli and the faithful replication of inserted sequences.

Effects of beta-naphthoflavone and 3-methylcholanthrene administered to pregnant rats on steroid metabolism in the isolated basal zone of the placenta

Steroid synthesis and metabolism were studied in the isolated basal zone of the rat placenta in which the steroidogenic giant trophoblast cells are localized. Incubation of [14C]progesterone with the 10,000 X g supernatant fraction of the basal zone from untreated animals resulted in formation of the following metabolites: 5 alpha-pregnane-3 alpha-ol-20-one, androstenedione, 17 alpha-hydroxy progesterone, 5 alpha-pregnane-3 beta-ol-20-one, testosterone and 5 alpha-pregnane-3,20-one. The multiple oxidized and reduced products of progesterone were resolved and radiochemically characterized by thin-layer chromatography in combination with high-pressure liquid chromatography. The administration of beta-naphthoflavone (beta-NF) and 3-methylcholanthrene (3-MC) during midgestation produced no adverse effects on maternal weight gain, fetal resorption rate, fetal body weight or basal zone weight when studied on day 15 of gestation. Both beta-NF and 3-MC treatments were associated with a 40 to 50% decrease in the formation of androstenedione, 17 alpha-hydroxy progesterone and testosterone. In addition the formation of 5 alpha-pregnane-3 alpha-ol-20-one, 5 alpha-pregnane-3 beta-ol-20-one and 5 alpha-pregnane-3,20-one was decreased by 30 to 60% in basal zone preparations from beta-NF- and 3-MC treated animals. Thus, the suppressed enzyme activities involve cytochrome P-450 dependent monooxygenase as well as 5 alpha-reductase pathways. Although neither beta-NF- nor 3-MC-treated animals showed evidence of in utero toxicity on day 15 of gestation, study of animals later in pregnancy on day 20 showed significant inhibition of late fetoplacental growth.(ABSTRACT TRUNCATED AT 250 WORDS)

The value of ultrasound measurement of amniotic fluid volume in the management of prolonged pregnancies

Ultrasound assessment of amniotic fluid volume was used to monitor 335 patients with prolonged pregnancy. Reduced amniotic fluid was diagnosed when no single vertical pool of amniotic fluid measured greater than 30 mm. Sixty-five patients with reduced amniotic fluid had labour induced while 270 patients with normal amniotic fluid were managed expectantly unless the cervix was favourable. Patients with reduced amniotic fluid had a statistically significant increase in meconium-stained amniotic fluid and growth-retarded babies and were more likely to require delivery by caesarean section for fetal distress. There were no perinatal deaths in the series and the perinatal outcome was satisfactory in both groups. Ultrasound measurement of amniotic fluid represents an effective discriminatory test in post-term pregnancy.

Spontaneous preterm labour and delivery at under 34 weeks' gestation

The management and outcome of 242 infants delivered between 26 and 34 weeks' gestation in an obstetrical and neonatal regional referral centre as a result of spontaneous preterm labour were recorded prospectively. Results of the survey show that the decision to intervene and delay delivery will depend on the availability of neonatal intensive care facilities. Infants likely to require intensive neonatal care should be transferred in utero to a centre with these facilities. The use of steroids reduces the mortality of preterm infants. The maximum effect occurs between 30 and 32 weeks' gestation, and there is no benefit after 34 weeks. If the weight is over 1500 g the mode of delivery of the preterm infant presenting by the breech does not influence outcome; if under 1500 g a caesarean section improves survival over those infants born by vaginal breech delivery.

Comparative mortality and morbidity of infants transferred in utero or postnatally

The outcome of two hundred and twelve infants transferred in utero and delivered in the regional neonatal intensive care center is compared with one hundred and sixty-six infants born elsewhere and transferred neonatally to the same unit, during the same period of time. The mean birthweight (+/- 1 S.D.) was 1391 g (+/- 415 g) for the infants transferred in utero, and 1398 g (+/- 415 g) for the infants transferred neonatally. The mean gestational age of the two groups was 29.9 completed weeks for both groups. Survival was defined as discharge from the neonatal unit and intraventricular hemorrhage was diagnosed ultrasonically. The survival rate was 83% for the group transferred in utero and 70% for the group transferred postnatally (p = less than 0.01). The incidence of intraventricular hemorrhage was 30% and 45% respectively (p = less than 0.01). Using birthweight specific perinatal mortality rates and intraventricular hemorrhage rates of the neonatally transferred group for standardisation, it can be calculated that 27 infants survived and 31 were protected from intraventricular hemorrhage because of in utero transfer. It is concluded that infants likely to require neonatal intensive care have decreased mortality and morbidity if transferred in utero to a center with these facilities rather than being transferred neonatally.

Non quantitative estimation of amniotic fluid volume in suspected prolonged pregnancy

A simple non-quantitative method of assessing the volume of amniotic fluid by ultrasound examination is described. The classification is based on the presence or absence of echo-free space between the fetal limbs and the fetal trunk or the uterine wall. In order to test the value of the classification, 150 patients with pregnancies of 42 weeks or more duration underwent ultrasound examination in the 48 hours prior to delivery. The patients classified as having "reduced" or "absent" amniotic fluid has statistically significant excess incidence of meconium stained liquor, fetal acidosis, birth asphyxia and meconium aspiration. The outcome of patients with "normal" amniotic fluid volume was excellent.