Maternal serum unconjugated oestriol and human chorionic gonadotrophin levels in pregnancies with insulin-dependent diabetes: implications for screening for Down's syndrome.

OBJECTIVE: To investigate maternal serum unconjugated oestriol (uE3) and human chorionic gonadotrophin (hCG) levels in pregnant women with insulin-dependent diabetes mellitus and to consider the implications of the results for antenatal screening for Down's syndrome. DESIGN: Descriptive study using stored antenatal serum samples. SETTING: Stored serum samples collected from women receiving routine antenatal care in Oxford. SUBJECTS: 126 singleton pregnancies in 92 women with insulin-dependent diabetes mellitus and for each pregnancy, two pregnancies without diabetes matched for gestational age and duration of storage of the serum sample. None of the pregnancies was associated with fetal neural tube defect or Down's syndrome. MAIN STUDY MEASURES: Maternal serum uE3 and hCG levels at 15-22 weeks gestation. Alpha-fetoprotein (AFP) levels were also measured for comparison. RESULTS: The median uE3 level in the diabetic pregnancies was 0.92 multiples of the median (MoM) for pregnancies without diabetes at the same gestational age (P less than 0.05); and the hCG level was 0.95 MoM (P = 0.48). The median AFP level was also reduced to 0.77 MoM (P less than 0.001). CONCLUSION: The reduction in uE3 and AFP levels in insulin-dependent diabetic pregnancies is sufficiently great to be taken into account in maternal serum screening programmes for Down's syndrome. Dividing the uE3 and AFP levels in such pregnancies by the corresponding median for insulin-dependent diabetic pregnancies will yield a similar false-positive rate in pregnancies with and without insulin-dependent diabetes mellitus.

The direct barbituric acid assay for nicotine metabolites in urine: a simple colorimetric test for the routine assessment of smoking status and cigarette smoke intake.

The qualitative direct barbituric acid (DBA) method of detecting urine nicotine metabolites was modified to make it quantitative. The performance of the quantitative DBA method was compared with the qualitative method and an established cotinine radio-immunoassay (RIA), using a panel of urines from 128 reported smokers and 383 reported non-smokers. The quantitative DBA method results were highly correlated with the cotinine RIA results, r = 0.85. The coefficients of variation for the two methods were 6% and 10%, respectively. Assuming that the reported smoking history was correct the qualitative DBA method gave a smoking detection rate of 91% and a false positive rate of 3%. At cut-off levels chosen to yield the same false positive rate the quantitative DBA method detected 93% of smokers, close to that of 98% detected with the cotinine RIA. The quantitative DBA method can be used to analyse over 170 samples per day compared to about 70 per day by RIA. It is therefore a fast and inexpensive alternative to cotinine assays for the assessment of smoking status and cigarette smoke intake.

The univariate and multivariate relationships among environmental, sociocultural, biological, and developmental variables and the identification of learning disabled children.

Multivariate techniques were used to study the relationships among environmental, sociocultural, biological, and developmental variables, and their ability to discriminate between learning disabled (LD) and regular education students. Univariate analyses were employed to identify variables that were included in a discriminant analysis. Through this combination of analyses, variables that might be considered as risk factors were isolated. Variables which contributed to the separation of LD children from those not placed in special education were developmental delays, baby's length at birth, and sex of child. Developmental delays and serious illness of the child were variables most contributing to the separation of LD from low achieving children. While not increasing the accuracy of classification, these antecedent variables appear to predict probability of LD placement as accurately as academic performance or clinical decision, thus allowing early intervention rather than procedures used after learning problems have been identified.

Pilot judgment: an operational viewpoint.

The process of decision making is poorly understood in our aviation environment. Accidents may demonstrate instances where incorrect decisions were made, but current investigative techniques do not necessarily give a clear understanding of why such decisions were made. The elements of the decision-making process need to be better understood so proper attention may be given to pilot training and developing operational procedures . A study of the Aviation Safety Reporting System data base was conducted to gain a better understanding of the actual operational impact of decision making.