摘要:

The results of 6121 prenatal diagnoses established by 46 centers in eight West-European countries are reported. The percentage of “spontaneous” abortions following early amniocentesis (1.4 %) does not seem to exceed the normal rate of spontaneous abortion in this period of pregnancy. A total of nearly 300 affected fetuses was detected, and in all but 5 instances the parents asked for interruption of the pregnancy. The majority of prenatal monitoring (75 %) was carried out because of an increased risk of chromosomal aberration. In the group with higher maternal age, 2.8 % of the fetuses were affected; this figure was 4.6 % for mothers older than 38 years. Monitoring because of an earlier child with trisomy 21 showed 1.3 % fetuses with a chromosomal aberration, and 1.7 % abnormal karyotypes were detected in the group where amniocentesis was performed for “miscellaneous reasons.” In pregnancies where a parental translocation had been demonstrated, 6.7 % of the fetuses showed an unbalanced karyotype and 25 % were balanced carriers. Also discussed are results and organizational problems of prenatal monitoring for inherited metabolic disorders (206 analyses for 23 different enzyme defects) and for neural tube defects (about 2700

ISSN:1424-8581    

DOI:10.1159/000130663

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The fluorescent properties of drumsticks, drumstick-like appendages, and other nuclear bodies in the polymorphonuclear leukocytes from six human males and females were studied with the aid of the quinacrine-mustard staining technique. Both brightly and weakly fluorescent drumsticks (in females) and drumstick-like bodies (in males) were observed, and they were readily differentiated on the basis of size, shape and, usually, fluorescent intensity. An analysis of the correlation between the extent of nuclear lobulation of the polymorphs and the corresponding fluorescent patterns of the adjoining drumsticks and drumstick-like bodies indicated that a possible change in the state and/or condensation of chromatin in these nuclear bodies might occur with increasing age of the polymorphs. Although the brightly fluorescent regions of the nuclei usually corresponded to the areas darkly stained with Giemsa, much finer patterns of differential staining of drumsticks and other nuclear bodies were obtained only by the fluorescent method.

ISSN:1424-8581    

DOI:10.1159/000130664

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Twenty-eight cases of chromosomal abnormalities were ascertained using G-banding. Seventeen of these had structural abnormalities of a complex nature and are discussed in detail. An independent assessment of chromosome abnormalities was carried out using sequential Q- and R-banding. In no case was there a difference in the identification of the abnormal chromosome, but in two cases a more precise localization or definition of the abnormality was obtained from the R-banded cells. In one case the initial diagnosis of the terminal deletion was altered to interstitial deletion; in the second case a break point in one chromosome involved in a reciprocal translocation was found to be in a different band by R-banding. In several others better delineation of break points or confirmation of complex abnormalities was obtained from the R-banded cells. R-banding was especially helpful in the localization of break points because of the color differentiation obtained with acridine orange. Q-banding was not found to have added any additional information. It was concluded from this study that the use of both G-banding and R-banding in complex abnormalities proved worthwhile.

ISSN:1424-8581    

DOI:10.1159/000130665

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The diploid chromosome number of 35 in the male and 36 in the female African marsh mongoose, Atilax paludinosus, has been confirmed. C- and G-banding analyses have shown that the Y chromosome is probably translocated onto the proximal end of the acrocentric partner of a heteromorphic autosomal pair (C3). The other partner is a subtelocentric with a heterochromatic short arm. During the translocation process, this short arm was removed and presumably lost. The sex determining mechanism in Atilax could be written as XX in the female and XYA-A in the male.

ISSN:1424-8581    

DOI:10.1159/000130666

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Terminal chromosome associations (“satellite associations”) in ASG-banded preparations have been used to determine the number and location of satellites in the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus). Five pairs of satellites are found in the former and four in the latter. Nucleolar organizing regions (NORs) were visualized with the Ag-AS silver precipitation technique, and their number and position corresponded exactly with the number and position of satellites in Phodopus, where positive chromosome identification can be made in the absence of banding. Numerical agreement is exact in Mesocricetus as well, and the morphology of the silver-tagged NOR-bearing chromosomes strongly suggests that correspondence also occurs in this spec

ISSN:1424-8581    

DOI:10.1159/000130667

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Chiasmata were counted and paired and unpaired configurations at first meiotic division and chromosome errors at second meiotic division were assessed at different ages in males and females of two strains of laboratory mice. In the females a decrease of chiasma frequency and an increase of univalents at first meiotic metaphase (MI) were confirmed. In the males, diakineses had higher chiasma frequencies (in the range of the female Mis) and fewer univalents than the MIs had. In these male cells there was no decrease of chiasmata or increase of autosomal univalents with age, and there were some interstrain differences. In the older females there was no parallelism between the frequencies of univalents at MI and the chromosome errors that could be identified at second meiotic division; these were fewer than might be expected on the assumption that all the univalents were true univalents. The relevance of this finding to the question of the nature of most of the univalents observed at first meiotic division in aged female mice is discussed.

ISSN:1424-8581    

DOI:10.1159/000130668

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130669

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130670

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130671

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130662

出版商:S. Karger AG    

年代:1976

数据来源: Karger