Thyroid antibodies are not a risk factor for pregnancies with down syndrome

The observation that thyroid disease is frequent in mothers of children with Down syndrome (DS) has suggested that maternal thyroid antibodies could be a factor predisposing to trisomy 21 in their offspring. In this study, the incidences of thyroglobulin (Tg) and thyroid peroxidase (TPO) antibodies were analysed with a sensitive solid-phase immunosorbent radioassay in sera from 29 mothers giving birth to children with trisomy 21 and 87 control mothers. The serum samples were collected at delivery. There was no statistical difference regarding the proportion of thyroid antibodies (against Tg and/or TPO) in the two groups. Thyroid antibodies were detected in 6/29 (20.7 per cent) of the DS mothers and in 23/87 (26.4 per cent) of the control mothers. Among the women with thyroid antibodies, 4/6 (66.7 per cent) of the DS mothers and 12/23 (52 per cent) of the control mothers had antibodies against both Tg and TPO. There was no increase in the relative risk of having a child with DS if the titre of either Tg or TPO antibodies or both were positive, i.e. ≥ 1/5. The results indicate that the presence of thyroid antibodies in the serum of a pregnant woman has no prognostic value for the birth of an infant with DS.     

北欧湖泊鱼类状况调查:酸化、富营养化和放养活动对现有鱼类品种组成的影响

1995～1997年间对挪威、瑞典和芬兰的3821个湖泊的鱼类种群状况做了评估.采用分层随机抽样从芬诺斯堪的亚(芬兰、挪威、瑞典、丹麦的总称)所有面积≥0.04km2的126482个湖泊中选择调查湖泊.分析了湖泊的水化学,湖内鱼类状况则从邮件调查问卷中获得.鱼类种群损失发生最为频繁的地区在挪威南部酸化最严重的地区,而在芬诺斯堪的亚东部最少.根据调查问卷,鳟(Salmotrutta)、拟鲤(Rutilus rutilus)、北极红点鲑(Salvelinus alpinus)和鲈鱼(Percafluviatilis)鱼群损失的数量估计超过10000条.这些品种的鱼群潜在地受低碱性湖水影响的数量超过11000条.大约有3300个湖泊显示出总磷高于25μg/L,品种以鲤科鱼为主,这在芬诺斯堪的亚东部、芬兰西南最为明显.这次调查并未显示出鱼类品种由于富营养化而灭绝.1/3的湖泊人工放养了至少一个新的鱼类品种,最常放养的品种有鳟、白鲑(Coregonus lavaretus s.1.)、北极红点鲑、虹鳟(Oncorhynchusmykiss)、梭鲈(Stizostedion lucioperca)、茴鱼(Thymallus thymallus)、狗鱼(Esox lucius)、欧鳊(Abramis brama)、丁 (Tinca tinca)和欧 (Phoxinus phoxinus).在芬诺斯堪的亚湖泊,这些品种的人工放养量估计超过52000群.因此,北欧湖泊现有鱼类品种的数量最近受放养的影响超过了因环境变化如酸化等而损失造成的影响.     

Peri- and paracentric inversions in chromosome 12: Prenatal diagnosis and family study

Three different types of chromosome 12 inversion were seen in 15 individuals out of 44 individuals examined in one 8 generation family. Type 1: a pericentric inversion inv(12) (p112; q131) was found in 7 individuals and twice at prenatal diagnosis. Type 2: a paracentric inversion inv(12) (p123; p131) was seen in two individuals. Two individuals carried both inversion chromosomes, namely type 1 and type 2. The two inversion chromosomes were transmitted from each of the parents. Type 3: a double pericentric and paracentric inversion (type 3) inv(12) (p123; p131) (p112; q131) was observed in the daughter of one of the carriers of type 1 and 2 inversions and again at prenatal diagnosis in her son. The double inversion most likely arose through crossing-over in between the two inversion loops. A balanced translocation t(7; 13) and the inversion type 1 was observed in one individual, who transmitted the translocation only to an offspring. The frequency of inversions in amniotic fluid cells observed in our laboratory was 1·9 per cent. The clinical implications of these findings are discussed.     

Ein quantitatives Strukturmaß in der digitalen Bildverarbeitung

Die Idee zu dieser Arbeit geht auf Diskussionen mit W. Priester über die Reduktion von Radiobeobachtungen ausgedehnter Galaxien im Jahre 1974 zurück. Die wesentlichen Teile wurden während eines Aufenthalts des Autors am Department of Astronomy, University of Florida, Gainesville, im Jahre 1987 entworfen. Ich habe ferner vielen Kollegen für hilfreiche Hinweise zu danken, darunter E. E. Baart, J. Condon, T. Cornwell, L. Erickson, S. Gottesman, J. Högbom, J. Skilling.