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Biomedical subjects

W Schnedl

Publications and source records attributed to W Schnedl.

At least 55 records · Page 3Linked to original sources
PubMed1977

DIPI and DAPI: fluorescence banding with only negliglible fading.

DIPI and DAPI produce distinct fluorescent bands in human chromosomes similar to quinacrine banding patterns. Additionally, the AT rich secondary constrictions in the chromosomes Nos. 1, 9 and 16 are brightly fluorescent. On the other hand the brilliantly fluorescent regions after staining with quinacrine mustard in the chromosomes Nos. 3 and 4, satellites and some other regions in the acrocentric chromosomes are less striking. The distal part of the Y, however, is clearly discernible. Thus DIPI and DAPI seem to be strictly AT specific fluorochromes like Hoechst 33258. In interphase nuclei the Y chromosome can be identified. However, quinacrines are superior for Y-body analysis in buccal, hair cell and sperm smears. BrdU labeled chromatids show reduced fluorescence intensity. The difference, however, is less apparent than after staining with Hoechst 33 258. DAPI and especially DIPI are highly resistant to UV-irradiation; there is almost no fading within 30 min when using DIPI. Moreover, fluorescence intensity is stronger than in quinicrines. When photographing, exposure times may be reduced to about one quarter compared to quinacrine mustard.

Amidines↗
PubMed1977

A photometric method for quantifying the polymorphisms in human acrocentric chromosomes.

Photometric measurements on photomicrographs of quinacrine mustard--stained metaphase chromosomes, processed by a reverse developing procedure provide quantitative data on the polymorphisms of human acrocentric chromosomes. The method described is intended for population studies. The method is easily reproducible, allowing comparisons of data obtained by different laboratories.

Chromosomes↗
PubMed1977

[Catamneses of YY carriers in prison].

Among the 700 inmates of a big Austrian prison 5 cases of XYY caryotype were detected by means of the Quinacrinfluorescence method and subsequent lymphocyte culture. Keeping in mind that, if at all, only a small amount of criminal behavior may be explained by chromosomal factors three hypotheses about possible links between the XYY abnormality and criminal behavior are discussed in this paper. 1. the connection is a spurious one, as both criminal behavior and the XYY caryotype are more frequent in a working class population without being necessarily linked causally. 2. criminal behavior may be a consequence of the bodily abnormalities connected with the XYY abnormality. 3. the XYY type may contribute to criminal behaviour by acting upon neuro-endocrinological structures.

Adult↗
PubMed1976

[Translocation (13; 18) (q22; p 11) and prenatal diagnosis (author's transl)].

A balanced translocation (13; 18) (q 22; p 11) was diagnosed in two generations. Out of 10 pregnancies in these two translocation carriers, mother and daughter, only two phenotypically normal childern were born. One of these, namely the daughter, showed balanced translocation, whilst a normal karyotype was diagnosed prenatally in the second case. The other eight pregnancies ended either in spontaneous abortions, in intrauterine death or in lethal malformations. In the present translocation the formation of unbalanced gametes seems to be enhanced.

Abnormalities, Multiple↗
PubMed1976

Increased sister chromatid exchange events in the human late replicating X.

Human female blood cultures were labeled with BrdU for detecting sister chromatid exchanges (SCEs) by the Hoechst 33258 fluorescence technique. Late labeling with 3H-thymidine and autoradiography allowed the identification of the late replicating X. The mean number of SCEs in the cells was 13. The isopycnotic X showed an exchange frequency according to its relative length in the karyotype; in the late replicating X a doubled number of SCE events was observed.

Chromatids↗
PubMed1976

Origin of the extra chromosome no. 21 in Down's syndrome.

Eighteen of 38 examined families with children with Down's syndrome showed polymorphisms of chromosome 21 elucidating the origin of the extra chromosome 21. Maternal origin was found in 10 cases and paternal origin in 8 cases. In both sexes errors occurred both in the first and in the second meiotic division.

Adult↗
PubMed1976

5-methylcytosine in heterochromatic regions of chromosomes in Bovidae.

The centromeric regions of cattle, goat and sheep chromosomes bind anti-5-MeC as revealed by immunofluorescence technique, indicating concentration of 5-MeC at these heterochromatic regions. The centromere of the submetacentric X of cattle remains nearly unstained and so do the centromeres of the acrocentric X chromosomes in goat and sheep. The short arm of the cattle Y exhibits strong anti-5-MeC binding whereas the tiny Y chromosomes of goat and sheep contain no brightly fluorescent material.

Animals↗
PubMed1976

8-methoxypsoralen and UVA promote sister-chromatid exchanges.

8-Methoxypsoralen (8-MOP) and long-wave UV light (UVA 365 nm) are now being use to treat vitiligo and psoriasis. Cultured human lymphocytes exposed to these agents in vitro show an increased infrequency of sister chromatid exchanges, related to 8-MOP-DNA photoadducts. Although these data raise questions regarding the biologic consequences of this therapeutic regimen, it is unknown whether 8-MOP and UVA cause mutations or extracutaneous somatic cell recombinants in vivo. Exchanges may represent cellular repair of DNA damage.

Cells, Cultured↗
PubMed1975

[New methods in cytogenetic diagnosis (author's transl)].

Several different methods for identifying human chromosomes were developed over the past years. These methods include fluorescence techniques using quinacrine mustard, acridine orange or Hoechst 33 258 and special methods using Giemsa staining. Studies on replication of chromosomes were greatly improved by using BUdR labelling.

Acridines↗
PubMed1975

5-Methylcytosine in heterochromatic regions of chromosomes: chimpanzee and gorilla compared to the human.

Fixed metaphase chromosomes of gorilla and chimpanzee were UV-irradiated to produce regions of single-stranded DNA and then treated with antibodies specific for the minor DNA base 5-methylcytosine (5 MeC). An indirect immunofluorescence technique was used to visualize sites of antibody binding. In the gorilla six pairs of autosomes contained major fluorescent regions, indicating localized regions of highly methylated DNA. These corresponded, with the exception of chromosome 19, to the major regions of constitutive heterochromatin as seen by C-banding. The Y chromosome also contained a highly fluorescent region which was located just proximal to the intense Q-band region. In the chimpanzee no comparable concentrations of highly methylated DNA were seen. Smaller regions of intense 5 MeC binding were present on perhaps six chimpanzee chromosomes, including the Y. Five of these corresponded to chromosomes which were highly methylated in the gorilla.--There is diversity among the human, gorilla and chimpanzee in both the size and location of concentrations of 5 MeC, supporting the idea that satellite DNA evolves more rapidly than DNA in the remainder of the chromosome.

Animals↗
PubMed1975

[A case of X/X translocation: t(X;X) (q26;p11)].

An eight-year old girl showing a X/X-translocation (45,X/46,Xt(X;X)(q26;p11)) is presented. Besides short stature and congenital heart-anomaly no other phenotypical abnormalities were present. In all cells containing the abnormal X-chromosome, the latter was late labeling as shown by autoradiography and BrdU-labeling.

Adult↗