Nucleated red blood cell counts in term neonates with umbilical artery pH < or = 7.00

The purpose of this study was to determine whether nucleated red blood cell (NRBC) counts are elevated in term neonates who have severe fetal acidemia at birth. The neonatal NRBC counts of term (gestational age > or = 37 weeks) neonates with pathological acidemia were compared with those from control neonates who met the following criteria: gestational age > or = 37 weeks, birth weight > or = 2800 g, umbilical artery pH > or = 7.25, and a 5-minute APGAR > 7. Pathological acidemia was defined as an umbilical artery pH < or = 7.0 and a base excess > -12 mEq/L. Twenty-six neonates met all inclusion criteria and were compared to 78 controls. The mean NRBC/100 WBC was 11.9 +/- 13.5 (range 0 to 45) for acidemic neonates compared to 3.9 +/- 2.9 NRBC/100 WBC (range 0 to 11) for control neonates [p <0.001]. Our findings suggest that the onset of hypoxia-ischemia in pregnancies complicated by severe fetal acidemia often begins prior to the intrapartum period.

Effects of intra-amniotic meconium exposure on the fetal rat: development of a pathogenic model

OBJECTIVE

To develop an in vivo animal model for the study of the effects of intrauterine meconium exposure on the fetus.

METHODS

Timed pregnant Long-Evans rats were purchased on gestational day (GD) 12 and allowed to acclimate for at least 48 h prior to surgery. Laparotomy was performed and both uterine horns were exteriorized through the abdominal incision. A 26-gauge needle was used to inject either 0.1-cm(3) sterile normal saline or a 20% meconium suspension into each individual gestational sac. The uterus was returned to the abdomen and the incision was closed. On GD 21 (term = 21 days) a cesarean section was completed and the number and viability of fetuses in each horn were recorded.

RESULTS

A total of 14 animals were involved in this pilot study. One rat underwent sham surgery with only intra-amniotic saline injection and 13/15 fetuses survived to term. Two animals that underwent surgery on day 18 expired < 24 h postinjection. Eleven maternal animals were injected on GD 20 and underwent cesarean delivery at term; survival rates for saline-injected animals were 71.2% compared to 66.2% for meconium-exposed fetuses.

CONCLUSION

We have established an in vivo animal model that allows for the examination of the effects of prolonged intrauterine meconium exposure on the fetus.

Meconium staining and meconium aspiration syndrome. Is there seasonal variation?

OBJECTIVE

To determine whether the incidence of pregnancies complicated by meconium-stained amniotic fluid (MSAF) or meconium aspiration syndrome (MAS) differs with seasonal changes.

METHODS

An established perinatal database was used to identify all term (> or = 37 weeks) singleton gestations resulting in a live birth from January 1, 1997 to December 31, 1999. Patients were divided into groups based on the season of delivery: winter (December-February), spring (March-May), summer (June-August), and fall (September-November). Rates of MSAF (%MSAF/total deliveries) and MAS (%MAS/total deliveries) were calculated and compared among seasons. Local climatic data (average monthly temperature and monthly precipitation) were obtained from the National Weather Service. Multiple logistic regression analysis was performed to control for the effects of confounding variables and odds ratio (OR) with 95% confidence intervals (CI) were calculated. p < 0.05 was considered significant.

RESULTS

Over the 3-year study period there were a total of 14,888 deliveries meeting the criteria. MSAF occurred in 3,206 (21.5%) deliveries and MAS developed in 92 (0.6% of total, 2.9% of MSAF). There were no differences in the rate of MSAF (p = 0.2) or MAS (p = 0.6) between seasons. By logistic regression neither season, temperature, nor precipitation were associated with MSAF or MAS.

CONCLUSIONS

Our findings suggest that over the period examined there were no significant seasonal variations in the incidence of MSAF or MAS.

The effects of intrapartum magnesium sulfate therapy on fetal serum interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha at delivery: a randomized, placebo-controlled trial

OBJECTIVE

Elevated levels of inflammatory cytokines in the fetus have been linked to neurologic morbidities in preterm neonates. Magnesium sulfate is currently being studied in clinical trials as a potential fetal neuroprotective agent. The purpose of this study was to determine whether intrapartum magnesium sulfate therapy has an effect on the umbilical venous concentrations of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha at delivery.

STUDY DESIGN

Women with singleton gestations >32 weeks with no clinical indications for magnesium sulfate therapy (preeclampsia or tocolysis) and either clinical chorioamnionitis or prolonged rupture of membranes were recruited for the study. Consenting patients were randomly assigned, in a double-blinded fashion, to receive either magnesium sulfate (6-g load then 2 g/hr) or matched volumes of lactated Ringer's solution until delivery. Fetal blood specimens were obtained by aspiration of the umbilical vein after cord clamping but before placental separation. Umbilical cytokine levels were measured with a sensitive and specific immunoassay.

RESULTS

Twenty-two patients were randomly assigned to groups and received either magnesium sulfate (n = 11) or placebo (n = 11). There were no differences in the demographic or clinical characteristics between groups. The umbilical venous ionized magnesium concentration was significantly higher in the magnesium sulfate group (2.32 +/- 0.27 mg/dL vs 1.23 +/- 0.15 mg/dL; P <.001). There were no statistically significant differences between groups with respect to umbilical levels of interleukin-1beta (1.5 pg/mL [1.5-58] vs 1.5 pg/mL [1.5-10]; P =.5); interleukin-6 (8.5 pg/mL [1-1000] vs 11.2 pg/mL [1-113]; P =.9); or tumor necrosis factor-alpha (16 pg/mL [7.6-20.3] vs 16.6 pg/mL [8.3-22.2]; P =.5).

CONCLUSION

In this pilot study the intrapartum administration of magnesium sulfate does not appear to affect the concentration of inflammatory cytokines in fetal blood at delivery.

Does cervical cerclage prevent preterm delivery in patients with a short cervix?

OBJECTIVE

Our purpose was to determine whether cerclage placement in women with a short cervix on transvaginal ultrasonography reduces the rate of preterm delivery.

STUDY DESIGN

A retrospective cohort study identified patients with an ultrasonographic short cervix (cervical length < or =15 mm) between 14 and 24 weeks' gestation. Cerclage placement was performed at the discretion of the attending physician. Clinical characteristics and outcome with and without cerclage were compared.

RESULTS

Seventy patients met inclusion criteria; 25 (36%) underwent cerclage placement. Patients managed with cerclage had a lower gestational age at diagnosis (19.6 weeks vs 21.3 weeks, P <.01) but had a similar median cervical length, presence of funneling, and a history of cervical surgery, in comparison with those managed without cerclage. The rate of spontaneous preterm delivery was not different between groups. Patients with cerclage had a higher rate of preterm premature rupture of membranes than those without cerclage (65.2% vs 36.4%, P <.05).

CONCLUSION

Cervical cerclage in patients with a short cervix did not reduce the rate of spontaneous preterm delivery and increased the risk of preterm premature rupture of membranes.

Meconium aspiration syndrome in term neonates with normal acid-base status at delivery: is it different?

OBJECTIVE

Our aim was to compare the clinical characteristics of meconium aspiration syndrome in cases with pH > or =7.20 and in those with pH <7.20.

STUDY DESIGN

Medical records of diagnostic codes from the International Classification of Diseases, Ninth Revision, were used to identify neonates with severe meconium aspiration syndrome who had been delivered at our institution from 1994 through 1998. Severe meconium aspiration syndrome was defined as a mechanical ventilator requirement of >48 hours. Clinical data including neonatal outcomes of cases of meconium aspiration syndrome associated with umbilical pH > or =7.20 at delivery were compared with data on outcomes of cases with pH <7.20.

RESULTS

During this 4-year study period, 4985 singleton term neonates were delivered through meconium-stained amniotic fluid. Forty-eight cases met all study criteria, and pH values at delivery were as follows: pH > or =7.20, n = 29, and pH <7.20, n = 19. There were no differences between groups in the incidence of clinical chorioamnionitis, in the presence of meconium below the vocal cords, or in birth weight. Neonates with meconium aspiration syndrome and umbilical pH > or =7.20 at delivery developed seizures as often as those with pH <7.20 (20.1% vs 21.1%; P = 1.0).

CONCLUSION

Normal acid-base status at delivery is present in many cases of severe meconium aspiration syndrome, which suggests that either a preexisting injury or a nonhypoxic mechanism is often involved.

Why are cesarean delivery rates so high in diabetic pregnancies?

AIMS

The purpose of this study was to examine factors relevant to mode of delivery in term pregnancies complicated by gestational and pre-gestational diabetes.

METHODS

A retrospective chart review of term (> or = 37 weeks) singleton pregnancies complicated by Class A2 through Class R pregnancies which delivered from 1991-1997 was performed. Exclusion criteria were prior cesarean delivery, non-vertex presentation, fetal structural defects, or any contraindications to vaginal delivery. Maternal and fetal factors relevant to mode of delivery were examined and compared. Stepwise logistic regression analysis was performed to examine factors predictive of delivery mode.

RESULTS

A total of 148 patients met study criteria. Induction rates were 60.9% for gestational and 79.8% for pre-gestational diabetics. The overall cesarean delivery rate by Diabetes Class for A2, B, C, D-F pregnancies was 20.3%, 40%, 37%, and 57.1% respectively. In Class A2 pregnancies no factor was associated with cesarean delivery and only nulliparity (p = 0.03) was associated in Class B-F pregnancies.

CONCLUSIONS

These results suggest that physician factors may play an important role in the risk for cesarean delivery in our diabetic population.

Relationship between the sonographic pattern of intrauterine growth restriction and acid-base status at the time of cordocentensis

OBJECTIVE

To determine whether there is a difference in acid-base status at the time of cordocentesis between fetuses with symmetric and asymmetric intrauterine growth restriction (IUGR).

STUDY DESIGN

Non-anomalous singleton fetuses with IUGR who underwent fetal blood sampling for rapid karyotype analysis from 1992-1995 were retrospectively identified. Cases with gestational age <24 weeks, abnormal karyotype, or evidence of congenital infection were excluded. Fetuses were divided into two groups based on Head Circumference/ Abdominal Circumference Ratio (HC/AC). The asymmetric-IUGR group had HC/AC > or = 95% tile for GA, and the symmetric-IUGR group had HC/AC <95% tile. GA adjusted values of umbilical venous pH, pCO2, pO2, HCO3, hemoglobin and reticulocyte count were calculated by subtracting the mean values for GA from the observed and compared between groups.

RESULTS

Both symmetric-IUGR (n = 7) and asymmetric-IUGR (n = 9) had umbilical venous pH and pO2, levels lower than GA normative values. However, there were no differences between groups for any of the parameters studied.

CONCLUSIONS

Fetuses with symmetric and asymmetric IUGR due to UPI display a similar degree of acid-base impairment.

Vaginal birth after cesarean in the diabetic gravida

OBJECTIVE

To compare the delivery outcomes in term diabetic patients without a prior cesarean delivery to those attempting vaginal birth after cesarean (VBAC).

STUDY DESIGN

A retrospective chart review study was performed of singleton pregnancies complicated by class A-2-R diabetes who delivered at > or = 37 weeks from 1991 to 1997. Exclusion criteria were prior classical or low vertical cesarean, more than one prior cesarean delivery, fetal structural defects or any contraindications to labor. Outcome measures were compared for patients without prior cesarean (group 1) to those with a VBAC attempt (group 2).

RESULTS

One hundred fifty-nine patients, 127 patients without a prior cesarean delivery and 32 patients with a VBAC attempt, met all the study criteria. The cesarean delivery rate was 26.3% (34/127) in group 1 and 56.3% (18/32) in group 2 (VBAC success rate, 43.7%). There were no cases of uterine rupture. There were no differences in the frequency of endometritis rates or neonatal intensive care unit admission, whether vaginal or cesarean delivery occurred.

CONCLUSION

VBAC success rates appeared to be lower for diabetic gravidas as compared to those for nondiabetic women reported in the literature. Although maternal and neonatal complication rates were low, further studies are necessary to determine the safety of VBAC in this population.

Influence of maternal-fetal medicine subspecialization on the frequency of trial of labor in term pregnancies with breech presentation

OBJECTIVE

To investigate the role of subspecialization in maternal-fetal medicine (MFM) on the frequency of a trial of labor in term pregnancies with breech presentation.

METHODS

We conducted a retrospective study of 332 singleton pregnancies > or =37 weeks with nonfootling breech presentation that delivered over a 6-year period (1994-1998) at a university-based, tertiary care hospital. Patients were divided into two groups based on whether the delivery was attended by an MFM or non-MFM obstetrician-gynecologist. Demographic and clinical data were compared between groups and outcome variables included whether the patient had an attempt at vaginal delivery, cesarean delivery after a labor attempt, or vaginal breech delivery.

RESULTS

The frequency of labor attempt (OR 1.4, 95% CI 0.9-2.3), vaginal breech success rate (OR 0.6, 95% CI 0.3-1.5), and overall cesarean rates (OR 0.9, 95% CI 0.5-1.7) were similar between groups. Using discriminant function analysis, only nulliparity (R2 = 1.6%, F = 6.0, P = 0.005) and birthweight (R2 = 2.0% F = 6.4, P = 0.01) were associated with trial of vaginal delivery.

CONCLUSIONS

Subspecialization in MFM had no impact on the frequency of trial of labor in the term pregnancy with a breech presentation.

The relationship between nucleated red blood cell counts and early-onset neonatal seizures

OBJECTIVE

This study was undertaken to better define the timing of neurologic insult in neonates with early-onset seizures through evaluation of neonatal nucleated red blood cell levels.

STUDY DESIGN

Medical records and the International Classification of Diseases, Ninth Revision codes were used to identify all term neonates with neonatal convulsions who were delivered at our institution (January 1, 1990-December 31, 1995). Each neonate with early-onset seizures was matched to the next 3 neonates who met the following criteria: gestational age > or =37 weeks, no early-onset seizures, birth weight > or =800 g, umbilical artery pH > or =7.25, and a 5-minute Apgar score >7. Demographic characteristics, clinical factors, and mean initial nucleated red blood cell counts were compared between groups.

RESULTS

During the 6-year study period, there were a total of 36, 490 singleton term deliveries of infants who were alive at birth. Forty-five (0.1%) of these neonates had early-onset seizures. Thirty neonates with early-onset seizures met the inclusion criteria. Mean nucleated red blood cell counts (number of nucleated red blood cells per 100 white blood cells) for neonates with early-onset seizures were significantly increased compared with those of control neonates (18.4 +/- 22.0 vs 4.6 +/- 4.5; P <.0008).

CONCLUSIONS

Our findings are suggestive of the hypothesis that neurologic injury leading to early-onset seizures often occurs before the intrapartum period.

Patients with an ultrasonographic cervical length < or =15 mm have nearly a 50% risk of early spontaneous preterm delivery

OBJECTIVE

The aim of this study was to determine the value in the prediction of spontaneous preterm delivery of ultrasonographically measured cervical length measured between 14 and 24 weeks' gestation.

STUDY DESIGN

A retrospective cohort study examined cervical length by means of a two-stage procedure, transabdominal ultrasonography followed by transvaginal ultrasonography if cervical length was <30 mm.

RESULTS

A total of 6877 patients met inclusion criteria. Mean cervical length was 37.5 mm. Odds ratios for early preterm delivery (< or =32 weeks' gestation) for patients with cervical lengths < or =10, < or =15, < or = 20, < or =25, and < or =30 mm were, respectively, 29.3 (95% confidence interval, 11.3-75.8), 24.3 (95% confidence interval, 12. 9-45.9), 18.3 (95% confidence interval, 10.8-31.0), 13.4 (95% confidence interval, 8.8-20.6), and 3.2 (95% confidence interval, 2. 4-4.4). For early preterm delivery a cervical length of < or =15 mm had a positive predictive value of 47.6%, a negative predictive value of 96.7%, a sensitivity of 8.2%, and a specificity of 99.7%.

CONCLUSIONS

A short cervix seen on a second-trimester sonogram was a powerful predictor of early spontaneous preterm delivery (< or =32 weeks' gestation). Nearly 50% of patients with a cervical length < or =15 mm had an early spontaneous preterm delivery, which suggests that clinical trials of interventions (eg, cerclage) in this population are urgently needed.

Suicidal ideation among college students in the United States

This study analyzed data from the 1995 National College Health Risk Behavior Survey (NCHRBS) to assess the prevalence of suicidal ideation among college students in the United States and to examine the association between suicidal ideation and substance use in this population. The NCHRBS used a mail questionnaire to assess health-risk behaviors in a nationally representative sample of undergraduate students. During the 12 months preceding the survey, 10% of the students had seriously considered attempting suicide. When controlling for demographic characteristics, the analysis showed that students who had considered suicide were at increased odds of using tobacco, alcohol, and illegal drugs. These results suggest that colleges and universities should establish suicide prevention programs that also address the related problem of substance use.

Suicidal ideation among college students in the United States

This study analyzed data from the 1995 National College Health Risk Behavior Survey (NCHRBS) to assess the prevalence of suicidal ideation among college students in the United States and to examine the association between suicidal ideation and substance use in this population. The NCHRBS used a mail questionnaire to assess health-risk behaviors in a nationally representative sample of undergraduate students. During the 12 months preceding the survey, 10% of the students had seriously considered attempting suicide. When controlling for demographic characteristics, the analysis showed that students who had considered suicide were at increased odds of using tobacco, alcohol, and illegal drugs. These results suggest that colleges and universities should establish suicide prevention programs that also address the related problem of substance use.

Expression and functional characterization of bluetongue virus VP2 protein: role in cell entry

Segment 2 of bluetongue virus (BTV) serotype 10, which encodes the outer capsid protein VP2, was tagged with the S-peptide fragment of RNase A and expressed by a recombinant baculovirus. The recombinant protein was subsequently purified to homogeneity by virtue of the S tag, and the oligomeric nature of the purified protein was determined. The data obtained indicated that the majority of the protein forms a dimer and, to a lesser extent, some trimer. The recombinant protein was used to determine various biological functions of VP2. The purified VP2 was shown to have virus hemagglutinin activity and was antigenically indistinguishable from the VP2 of the virion. Whether VP2 is responsible for BTV entry into permissive cells was subsequently assessed by cell surface attachment and internalization studies with an immunofluorescence assay system. The results demonstrated that VP2 alone is responsible for virus entry into mammalian cells. By competition assay, it appeared that both VP2 and the BTV virion attached to the same cell surface molecule(s). The purified VP2 also had a strong affinity for binding to glycophorin A, a sialoglycoprotein component of erythrocytes, indicating that VP2 may be responsible for BTV transmission by the Culicoides vector to vertebrate hosts during blood feeding. Further, by various enzymatic treatments of BTV-permissive L929 cells, preliminary data have been obtained which indicated that the BTV receptor molecule(s) is likely to be a glycoprotein and that either the protein moiety of the glycoprotein or a second protein molecule could also serve as a coreceptor for BTV infection.

Spectrophotometric and spectrofluorimetric determination of fluorouracil in the presence of its degradation products

Three reliable spectrophotometric and spectrofluorimetric procedures are described for the determination of fluorouracil in bulk powder and ampoules in the presence of its degradation products. One spectrophotometric procedure, based on measurement at 555 nm of the violet-coloured complex formed by fluorouracil with cobalt(II), has a detection limit of 0.03 mg mL(-1). Two sensitive spectrofluorimetric procedures are also proposed. One is based on measurement of the intrinsic fluorescence of the liberated fluorouracil at 375 nm, after precipitation as its cobalt(II) complex, decomposition of the precipitate with sulphuric acid and excitation at 295 nm. The second depends on excitation of the fluorouracil-cobalt(II) complex at 395 nm and measuring its fluorescence at 483 nm. The limits of detection of the two spectrofluorimetric procedures are 0.5 and 2 microg mL(-1), respectively. The three procedures have been used successfully for the determination of fluorouracil ampoules. The validity of the methods has been assessed by applying the standard addition technique.

Determination of glafenine in dosage forms and serum by thin layer densitometry and high performance liquid chromatography

New thin layer densitometry and high performance liquid chromatography (HPLC) methods are described for quantitative determination of glafenine in dosage forms in the presence of its photo-degradation products and in serum in the presence of its metabolites. Mobile phases consisting of toluene-isopropyl alcohol-dimethylformamide-water (18:3:1:0.5) and methanol-water-phosphoric acid (80:120:0.5) are found to be efficient for reasonable separation and adequate resolution of glafenine from associated substances by thin layer chromatography (TLC) and HPLC techniques, respectively. The methods are used for the study of glafenine purity, stability, bioavailability, bioequivalence and tablet dissolution rate. The results obtained by TLC and HPLC techniques are in good agreement and offer the advantages of reproducibility and accuracy.

Vascular disruption birth defects and history of prenatal cocaine exposure: a case control study

OBJECTIVE

To test the hypothesis that prenatal cocaine exposure is associated with a 3-fold increased risk for vascular disruption among malformations.

STUDY DESIGN

A retrospective case-control study was based upon >68,000 delivery records at Hutzel Hospital for a 9-year period. Ascertainment was based upon ICD-9 codes for limb defects, abdominal wall defects, and facial clefts. Transverse limb defects and gastroschisis were defined as cases, and nondisruption anomalies served as controls. Statistical analysis for history of maternal cocaine use reported during pregnancy was performed by chi(2) analysis and the odds ratio determined.

RESULTS

A total of 190 cases of limb anomalies, abdominal wall defects, and cleft lips were identified after exclusion criteria. Statistical analysis was performed on the 119 cases informative for maternal cocaine use during pregnancy. Seven of 34 vascular disruption cases had cocaine exposure reported versus 12 of 85 other malformations controls. The odds ratio for cocaine exposure and vascular disruption is 1.58 (95% confidence interval = 0.55-4.47).

CONCLUSION

The putative association of prenatal cocaine exposure and vascular disruption birth defects remains unresolved, but the attributable risk is very likely less than the 3-fold odds ratio previously reported.

Miniaturized graphite sensors doped with metal-bathophenanthroline complexes for the selective potentiometric determination of uric acid in biological fluids

Miniaturized poly(vinyl chloride) matrix membrane sensors in an all-solid-state graphite support, responsive to urate anion, were developed. The membranes incorporate lipophilic ion-pair complexes of urate anion with ruthenium(III), iron(II), nickel(II) and copper(I) bathophenanthroline (4,7-diphenyl-1,10-phenanthroline) counter cations. The sensors demonstrate a near-Nernstian response to urate over the concentration range 1 x 10(-2)-1 x 10(-5) mol l-1 and have micromolar detection limits and good selectivity properties. The response is virtually unaffected by pH changes in the range 7-10 and the response times are 5-10 s in aqueous solutions and in human serum and urine samples. A flow injection detector incorporating an iron(II) bathophenanthroline-urate graphite sensor was used for continuous monitoring of uric acid. The minimum detectable concentration was approximately 8 micrograms ml-1 and the sample throughput was approximately 120 h-1. Direct potentiometric determination of uric acid in the static and hydrodynamic modes of operation over the range 15 micrograms ml-1-1.5 mg ml-1 showed average recoveries of 98.7 and 97.8% with RSDs of 0.6 and 0.7%, respectively. Application of the method to the determination of uric acid in human serum and urine gave results that compared favourably with those obtained by the standard spectrophotometric method.

Cross-sectional serosurvey for Japanese encephalitis specific antibody from animal sera in Malaysia 1993

Serum specimens were collected from 6 species of animals living in 9 states of Malaysia including Sabah, North Borneo in 1993. Antibodies against Japanese encephalitis (JE) virus in these sera were detected by means of hemagglutination-inhibition (HI) and neutralization (NT) tests. By HI test, 702 of 2,152 (32.6%) sera showed positive results. Higher positive rates were obtained by the NT test, in which 1,787 of 1,927 (92.7%) sera had antibodies against JE virus. All serum specimens with positive HI were confirmed as positive by the NT. Swine sera showed especially higher rates of antibody positive and higher antibody titers compared with other animals. These results suggest that JE infections are widely distributed among many animals of Malaysia, and pig is the most susceptible amplifier host for JE virus.