Prenatal diagnosis of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency in a family with a previous fatal case of sudden unexpected death in childhood

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a potentially fatal inherited disease with a carrier frequency of approximately 1:100 in most Caucasian populations. The disease is implicated in sudden unexpected death in childhood. A prevalent disease-causing point mutation (A985G) in the MCAD gene has been characterized, thus rendering diagnosis easy in the majority of cases. Since the clinical spectrum of MCAD deficiency ranges from death in the first days of life to an asymptomatic life, there are probably other genetic factors—in addition to MCAD mutations—involved in the expression of the disease. Thus, families who have experienced the death of a child from MCAD deficiency might have an increased risk of a seriously affected subsequent child. In such a family we have therefore performed a prenatal diagnosis on a chorionic villus sample by a highly specific and sensitive polymerase chain reaction (PCR) assay for the G985 mutation. The analysis was positive and resulted in abortion. We verified the diagnosis by direct analysis on blood spots and other tissue material from the aborted fetus and from family members.     

Expanding multiple marker screening for Down's syndrome to include Edward'S syndrome

Information on maternal age and maternal serum alpha-fetoprotein, unconjugated oestriol (uE₃), and human chorionic gonadotrophin (hCG) levels was used to investigate retrospectively the effect of estimating Edward's syndrome risk in women having multi-marker screening for Down's syndrome. The screened population comprised 15 pregnancies affected by Edward's syndrome, 15 with Down's syndrome and 5472 unaffected pregnancies. The use of all three markers to estimate Edward's syndrome risk would have led to the detection of 10–12 (67–80 per cent) cases with a false-positive rate of 0.3–0.6 per cent depending on the risk cut-off. A further case would have been detected as a result of screening for Down's syndrome alone. Similar results were obtained when the Edward's syndrome risk was based on uE₃ and hCG only. These data suggest that extending Down's syndrome screening to include Edward's syndrome risk will yield a high detection rate with only a small increase in the false-positive rate.     

Service transformation—managing a shift from business travel to virtual meetings

It has been shown that the potential for environmental, and financial improvements through the increased substitution of in-person meetings by virtual communication is considerable. However, it has also been shown that this potential is not automatically realized by investing in the technology that can enable virtual meetings. This paper describes two case studies that explored the factors that influenced communication and meeting behavior. A number of drivers and barriers for virtual meetings are identified, and, in addition, measures are proposed to improve the utilization of virtual tools for business communication.     

土壤中水溶氟与总氟和土壤PH值的相关分析

使用实测资料，利用数理统计方法分析了土壤中水溶氟与总氟和土壤ＰＨ值三者间的相关关系，提出了在背景地区，土壤水溶氟与总氟、土壤ＰＨ值间无相关性；与土壤ＰＨ值间无相关性的结论。     

Hepatic calcifications in a fetus with trisomy 9 that underwent cordocentesis

Foci of calcification were observed at autopsy in the liver of a fetus with complete trisomy 9 on which two cordocenteses had been performed. It is suggested that liver calcifications are a possible complication of the procedure. As several other cases of calcifications in the liver and other organs of fetuses with autosomal trisomies have been described without a history of cordocentesis, further studies should be carried out to determine whether fetuses with chromosomal anomalies are more prone to thrombus formation and embolization.     

Serum PAPP-A measurements in first-trimester screening for Down syndrome

Serum PAPP-A measurements taken from 254 women in the first trimester are reported. Eleven chromosomal abnormalities were detected. The mean serum PAPP-A levels in cases of Down syndrome were 0.44 MOM at 9 weeks gestation, 0.15 MOM at 10 weeks, and 0.29 MOM at 11 weeks. The PAPP-A level at 10 weeks was below those of pregnancies which aborted spontaneously. At 11 weeks, the pregnancies with Down syndrome recorded the lowest PAPP-A levels at that gestation. On this small sample, offering chorionic villus sampling to women with singleton pregnancies and a PAPP-A level below 0.3 MOM (approximately 6.5 per cent of this at-risk group) would have detected all the Down syndrome fetuses at 10 weeks and 50 per cent at 11 weeks without selecting those cases destined to abort. This suggests that serum PAPP-A should continue to be investigated as a potential first-trimester screening test for Down syndrome.     

Cellular and ultrastructural changes in the endoderm of the temperate sea anemone Anemonia viridis as a result of increased temperature

Exposure of the temperate sea anemone Anemonia viridis Forskål to increased seawater temperature (from 16 to 26°C) reduced the lysosomal latency of coelenterate tissues. Lysosomes in the mesenterial filaments of anemones were destabilised by increased temperature, with greater destabilisation in heat-shocked symbiotic anemones than in heat-shocked aposymbiotic anemones in the early stages of the experiment. Lysosomal enzyme activity in zooxanthellae from heat-shocked symbiotic anemones was associated with the algal membranes and the cytoplasm of degenerate algal cells. While the relationship between host coelenterate and symbiotic alga may confer many benefits under normal conditions, comparison of the responses of symbiotic and aposymbiotic anemones to heat shock suggests that there may be disadvantages for symbiotic anemones under stress.     

Major primary stages of biomineralization in radular teeth of the limpet Lottia gigantea

The radula (feeding organ) of the limpet Lottia gigantea is a membraneous ribbon to which are attached up to 150 transverse rows of teeth. The organic matrix of the teeth is impregnated with inorganic salts (Fe, Si, Ca). In its posterior end, the radula originates from a radular gland which is coiled dorsally, where long odontoblast cells secrete the tooth and the radular membrane. Teeth mature gradually. The organic matrix of this complex was stained homogeneously in the first five rows (hematoxylin-eosin). From Row 6 onward, the tooth became demarcated from the radular membrane by forming segments within the matrix of the radular membrane. The cusp's organic matrix milieu was histologically divided into two main domains, internal and external, each one consisting of fibrillar milieu. Teeth are embedded within the tall columnar superior epithelium, which superimposes the cusps. Iron-bearing granules started to appear in these cells beginning at Rows 7 to 10, increasing in number to Row 20 and continuing to at least Row 65. Iron proceeded to infiltrate first into the internal part of the cusp at Row 15. The outer part of the cusp was mineralized beginning at Rows 22 to 27. At about Row 30, the cusp was heavily mineralized by iron. Calcium was deposited into the radular membrane and tooth bases from the most posterior part. It is concluded that radula biomineralization is subject to highly complex but precisely controlled cytological-biochemical processes and that different parts of each young tooth are subjected simultaneously to different biomineralization pathways. Specimens used in this study were collected in 1984 from the intertidal zone at La Jolla, California.