Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by steroid analysis in the amniotic fluid of mid-pregnancy: Comparison with HLA typing in 17 pregnancies at risk for CAH

Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies.     

英国塘鹅蛋中多氯联苯同类物的时空变化趋势

1977～1998年间,在苏格兰西部的艾尔萨克雷格对收集到的塘鹅蛋中的多氯联苯(PCB)同类物进行了回顾性分析.对一些年份所收集的塘鹅蛋中每年选择8～10个对其PCB同类物浓度范围分别进行了分析.所有的同类物在几年之内浓度都降在低,但不同的同类物降解速率不同.     

Climate anomalies, Indonesian vegetation fires and terrestrial carbon emissions

There was a widespread misconception about the causes of vegetation and land fires in Indonesia. At a certain point, the public perceived that fires and the associated haze pollution were primarily caused by smallholders' agricultural activities. In fact, there was a variety of land-use activities including large-scale land clearing following deforestation for further land development. El Niño events and the associated dry weather were sometimes quoted by officials and the media as the cause of fires. The fire episodes from 1980 to 2000 were analysed in connection with climate anomalies and the implementation of land-use policies related to forest conversions. The analysis employs long-term climatic and sea surface temperature data to reconstruct climate distributions and anomalies including Southern Oscillation Index (SOI), Sea Surface Temperature (SST) and Outgoing Long-wave Radiation (OLR). In this study, the terrestrial carbon emissions from vegetation fires were estimated based on official statistical data on area burnt. The possible incentives for sustainable land management were discussed in the light of fire prevention. The underlying cause neglected in the discussion of Indonesian vegetation fires was forest and land development policy. Legitimated in the early 1980s, it drove massive forest conversions and the use of fires for land clearing. El Niño Southern Oscillation (ENSO) provided dry weather suitable for biomass burning and widespread fire, but it was hardly the cause of fires. The estimate of area burnt in the big fires in 1997 was about 11.6 Mha, resulting in carbon release of 1.45 Gt, equivalent to 0.73 ppmv of CO₂, or almost half the annual global atmospheric CO₂ growth. Based on the current carbon market price such emissions by the 1997 fire episode were worth around US$ 3.6 billion.