Specific Karyological Features of Siberian Stone Pine (Pinus sibirica Du Tour) in Western Siberian Bogs

The results of a karyological study on Siberian stone pines growing in the bog demonstrated differences from the populations of this species studied earlier with respect to sizes of chromosomes and location of secondary constrictions. The number of nucleolar organizer regions in the chromosomes of Siberian stone pine trees growing in the bog was larger than in other populations. A wide spectrum of chromosome aberrations was revealed, which had not been observed in this species before. These were genome and chromosome aberrations of various types, as well as structural aberrations accompanied by changes in the number of chromosomes. It is assumed that the aberrations in the karyotype of Siberian stone pine resulted from stressful conditions.     

Normal karyotype in cultured chorionic villus cells,but mosaicism in amniotic and fetal cells

A case with a normal male karyotype in cultured chorionic villus cells, but 46,XY/45,X/ 46,X,i(Yq) mosaicism in amniotic and fetal tissue is reported. The fetus was a phenotypic male. Pathological examination revealed discrete features, which might indicate a syndrome, and histological examination showed large, bright cells in the tubules of the testes. Possible explanations for discordance between the karyotype of embryonic and extraembryonic tissue are discussed.     

Identification of abnormal chromosomal complement in formalin-fixed,paraffin-embedded placental tissue

The objective of this project was to assess the efficacy of fluorescence in situ hybridization (FISH) with chromosome-specific DNA probes to identify chromosome number in formalin-fixed, paraffin-embedded placental specimens. Using this approach, 75 per cent of the karyotypes in 20 formalin-fixed placental samples (comprising aneuploids, triploids, and normals) were correctly identified. As this technology improves, the ability to obtain information regarding chromosomal abnormalities in formalin-fixed, paraffin-embedded placental tissue should improve as well. This technology can potentially provide important cytogenetic information even when fresh tissue is not available for standard karyotypic analysis.     

Fetal karyotypes from fetoscopy blood samples

The fetal karyotype was determined in 42 out of 45 cases from fetal blood obtained by fetoscopy for prenatal diagnosis of β-thalassemia. The procedure described is quick and reliable and it is recommended for women over 35 years of age undergoing prenatal diagnosis for haemoglobinopathies.     

Cytogenetic abnormalities among perinatal deaths demonstrating a single umbilical artery

The presence of a single umbilical artery is associated with fetal congenital malformations and cytogenetic abnormalities. The incidence of chromosomal abnormalities in perinatal deaths complicated by a single umbilical artery is unknown. We studied the proportion of cytogenetic abnormalities associated with a single umbilical artery among perinatal deaths undergoing autopsy. Of 1078 autopsies, 42 (3·9 per cent) were identified with a single umbilical artery. Chromosome analysis was attempted in 21 of the 42 cases (50 per cent). There were 16 successful chromosome analyses, of which three (18·75 per cent) were abnormal. All the chromosomally abnormal fetuses had major congenital malformations. These data suggest that in a perinatal death, the presence of a single umbilical artery does not clinically alter the a priori risk of cytogenetic abnormalities.     

游蛇科4种的核型比较

以骨髓细胞直接制备染色体标本，分析了游蛇属（Ｎａｏｔｒｉｘ）３种和链蛇属（Ｄｉｎｏｄｏｎ）１种蛇的核型．草游蛇（Ｎ．ｓｔｏｌａｔａ）２ｎ＝３６，１８（１５Ｍ＋１ＳＴ＋２Ｔ）·１８ｍ（♀）．渔游蛇（Ｎ．Ｐｉｓｃａｔｏｒ）２ｎ＝４０，１６（１０Ｍ＋１ＳＭ＋３ＳＴ＋２Ｔ）·２４ｍ（♀）．乌游蛇（Ｎ．ｐ．ｐｅｒｃａｒｉｎａｔａ）２ｎ＝４０，１８（８Ｍ十２ＳＭ＋８Ｔ）·２２ｍ（♂）．赤链蛇（Ｄ．ｒｕｆｏｚｏｎａｔｕｍ）２ｎ＝４６，２０（１Ｍ＋３ＳＭ＋１６Ｔ）·２６ｍ（♀）．草游蛇和渔游蛇的Ｎｏｓ，赤链蛇的Ｎｏ３为ＺＺ／ＺＷ型性染色体．草游蛇Ｚ染色体为Ｍ型，Ｗ染色体为ＳＴ型；渔游蛇Ｚ为ＳＭ型，Ｗ也是ＳＴ型；赤链蛇Ｚ为Ｍ型，Ｗ为ＳＭ型．三者Ｚ均略大于Ｗ．草游蛇和渔游蛇Ｎｏ４长臂末端有时可见随体．对游蛇属、链蛇属以及游蛇亚科（Ｃｏｌｕｂｒｉｎａｅ）已知各属种的核型进行了比较和讨论．     

Prediction of an abnormal karyotype in fetuses with omphalocele

The aim of this study was to assess the value of ultrasonographic evaluation in predicting abnormal karyotypes in fetuses with omphalocele. Forty fetuses with antenatally diagnosed omphalocele and available karyotype results were reviewed. Ultrasound evaluation included herniation contents and size, and the detection of other anomalies. Nine of 40 consecutive fetuses had abnormal karyotypes: trisomy 18 (n = 5), trisomy 13 (n = 3), 47,XXX (n = 1). Only 1/25 with an extracorporeal liver versus 8/15 with an intracorporeal liver had abnormal chromosomes [P = 0·0006, RR = 0·14 (0·02 < RR <0·9)]. Small defects (<3 cm) were associated with abnormal karyotypes [P = 0·01, RR = 4·7 (1·4<RR <15·6)]. Finding concurrent malformations was highly associated with chromosomal anomalies [P = 0·00004, RR = 4·4 (2·3 < RR < 8·5)]. The presence of associated malformations, an intracorporeal liver, and a small herniation size are highly suggestive of an associated abnormal karyotype.