PubMed Health⌕ Search

Biomedical subjects

U Müller

Publications and source records attributed to U Müller.

At least 451 records · Page 25Linked to original sources
PubMed1987

A 45,X male with Y-specific DNA translocated onto chromosome 15.

A 20-year-old male patient with chromosomal constitution 45,X, testes and normal external genitalia was examined. Neither mosaicism nor a structurally aberrant Y chromosome was observed when routine cytogenetic analysis was performed on both lymphocytes and skin fibroblasts. Y chromosome-specific single-copy and repeated DNA sequences were detected in the patient's genome by means of 11 different recombinant-DNA probes of known regional assignment on the human Y chromosome. Data indicated that the short arm, the centromere, and part of the long-arm euchromatin of the Y chromosome have been retained and that the patient lacks deletion intervals 6 and 7 of Yq. High-resolution analysis of prometaphase chromosomes revealed additional euchromatic material on the short arm of one of the patient's chromosomes 15. After in situ hybridization with the Y chromosome-specific probe pDP105, a significant grain accumulation was observed distal to 15p11.2, suggesting a Y/15 chromosomal translocation. We conclude that some 45,X males originate from Y-chromosome/autosome translocations following a break in the proximal long arm of the Y chromosome.

Adult↗
PubMed1987

Mapping of testis-determining locus on Yp by the molecular genetic analysis of XX males and XY females.

Sex reversal in males with female karyotypes is likely to be caused by the presence of cytogenetically undetectable Y-chromosomal DNA sequences that include the testis-determining gene(s). Studying a total of sixteen 46,XX males and one 47,XXX male, we detected Y-chromosomal DNA in 13 of the XX males (i.e. 80%) and in the 47,XXX male. The amount of Y-chromosomal DNA present in the patients varied between individuals. This allowed the construction of a molecular map of the Y-chromosome short arm. The putative testis-determining locus was assigned to the more distal portion of Yp, yet proximal to the pseudoautosomal region. Mapping of the testis-determining locus was complemented by molecular findings in 46,XY females. These individuals may carry microdeletions of the portion of Yp that appears to be required for normal male gonadogenesis. The deletions detected in 46,XY females always included those Y-chromosomal DNA sequences that were found in most 46,XX males. Furthermore, the same DNA sequences were missing in a female with a 46,X,dic(Y) karyotype. The observations suggest that some of our DNA probes hybridize with Y-chromosomal DNA sequences within a few million base pairs of the testis locus. Chromosome walking and pulsed-field gel electrophoresis investigations have been initiated in order to isolate those Y-chromosomal DNA sequences that are required for normal testicular development.

Chromosome Mapping↗
PubMed1986

[Allergic angioedema after local dental anesthesia and a hyaluronidase-containing preanesthetic injection solution].

Two patients are described who developed allergic angioedema following local anesthesia for dental surgery. Skin testing revealed that hyaluronidase from bull testes contained in one of the preparations used for local anesthesia was the responsible allergen. In both patients hyaluronidase-specific serum IgE antibodies were detected by RAST. Mammalian hyaluronidase, also called spreading factor, is believed to improve penetration of tissues by local anesthetics. It is used worldwide for this and other indications. In the presence of allergic reactions to local anesthetics the possibility of sensitization to hyaluronidase should be considered.

Adult↗
PubMed1986

[Synergistic inhibition of thrombocyte activation by drugs added in pairs].

Synergistic activity on human platelets can be observed between two platelet agonists administered in threshold doses ("threshold synergism"). We were therefore interested to learn whether certain drugs known to inhibit platelet activation at high concentrations also exert a synergistic inhibitory activity if added in pairs at threshold doses to the platelets prior to activation. Samples of platelet-rich plasma were preincubated with either single drugs or pairs of drugs or saline (control). Platelet activation was performed in an aggregometer. Activation was registered as aggregation; in addition, either release of serotonin or beta-thromboglobulin was measured. All six drugs tested (propranolol, diclofenac, dipyridamole, theophylline, verapamil, ceftriaxone) clearly exhibited--independently of their inhibitory mechanisms--an additive or even synergistic inhibition of platelet activation if given in pairs. This finding may explain the clinical observation that patients under treatment with two or more such drugs develop a functional defect of platelets as the only explanation for an acquired hemorrhagic diathesis.

Blood Platelets↗
PubMed1986

Deletion mapping of the testis determining locus with DNA probes in 46,XX males and in 46,XY and 46,X,dic(Y) females.

Eleven Y-specific DNA probes hybridizing with DNA from one or more 46,XX males were isolated from a recombinant phage DNA library constructed from flow sorted human Y chromosomes. Two probes hybridized with DNA from nine out of eleven, i.e. greater than 80% of these 46,XX males. The relative frequency of hybridization of the probes in the 46,XX males and in a 46,X,dic(Y) female, together with in situ hybridization data, allowed mapping of the probes on Yp in relation to a putative testis determining locus. Several of those probes were also absent in a 46,XY female, further refining a model for ordering the probes on Yp. The DNA of one XX male hybridized both with probes from Yp and probes from proximal Yq (excluding the pericentral region). This suggests that complex translocations may occur into the DNA of 46,XX males that involve not only parts of Yp but also parts of Yq.

Chromosome Aberrations↗
PubMed1986

A sensitive and rapid gel retention assay for nuclear factor I and other DNA-binding proteins in crude nuclear extracts.

The paper describes a rapid and sensitive assay for DNA binding proteins which interact with specific and defined binding sites. It exploits the observation that complexes of proteins and small synthetic DNA fragments (40 bp) containing the protein/DNA binding site can enter native polyacrylamide gels and remain stably associated during electrophoresis under non-denaturing conditions. The assay was applied to nuclear factor I, to its identification and purification from porcine liver, to an analysis of its binding site on adenovirus type 5 DNA and to an exploration of other potential binding sites for DNA binding proteins within the inverted terminal repetition of adenovirus DNA. The extreme sensitivity of the assay which surpasses that of conventional footprint assays by at least two orders of magnitude permitted the identification of nuclear factor I-like activities in Saccharomyces cerevisiae.

Animals↗
PubMed1986

Moderately repeated DNA sequences specific for the short arm of the human Y chromosome are present in XX males and reduced in copy number in an XY female.

Four DNA sequences specific for the Y chromosome were isolated from a recombinant phage library constructed from flow sorted human Y chromosomes. Two of these sequences were moderately repeated and assigned to the short arm of the Y chromosome by in situ hybridization. Both sequences were detected in five out of six [corrected] 46,XX males and were reduced in copy number in one out of two 46,XY gonadal dysgenesis patients tested. The findings suggest close proximity of these Y-specific moderately repeated DNA sequences to a testis determining locus.

Cell Fractionation↗
PubMed1986

Construction, analysis, and application to 46,XY gonadal dysgenesis of a recombinant phage DNA library from flow-sorted human Y chromosomes.

The analysis of a recombinant human Y-enriched Hind III total digest phage library prepared from the DNA of flow sorted human Y chromosomes is described. Out of 43 phage inserts from the library thus far mapped, 25 revealed hybridization with Y chromosomal DNA. These inserts may be divided into five groups according to their degree of Y specific hybridization: inserts that hybridize with one single copy or slightly repeated Y-specific DNA sequence, Y-specific repeated sequences of various restriction fragment lengths, Y-chromosomal DNA sequence(s) shared by a sequence on the X and/or on autosomes, Y-specific DNA sequences in addition to multiple X and/or autosomal sequences, or Y-specific repeated DNA in addition to multiple X and/or autosomal sequences. Application of probes from this library for diagnostic purposes is shown in two 46,XY patients with gonadal dysgenesis and small deletions of the Y short arm.

Cloning, Molecular↗
PubMed1986

Repeated DNA sequences in the distal long arm of the human X chromosome.

Two DNA probes from within a single large insert from a recombinant phage-DNA library that was constructed from flow-sorted chromosomes enriched for the human X chromosome were shown to hybridize with repeated X-specific and autosomal DNA sequences. The X-chromosomal repeated sequences were assigned to the distal long arm of the X chromosome by both hybrid mapping and in situ hybridization. Fine mapping places these repeats in a region of Xq28 between DX13 (DXS15, in distal Xq28) and factor VIII (F8C, in proximal Xq28). The location of the X-specific repeats makes them potentially useful for future investigations of diseases mapping to the distal long arm of the X chromosome, such as the fragile X syndrome.

Animals↗
PubMed1986

[Determination of piperazine in hen eggs with HPLC following oral administration].

After oral administration of piperazine citrate to hens, this antihelmintic agent appeared unchanged in the eggs. After a therapeutic dose of ca. 0.9 g piperazine citrate per hen, a maximum level of 1.5 mg piperazine/kg egg was found two days after the application. The elimination half-life was 29 h and piperazine was found in the eggs up to 17 days after administration (limit of detection: 1 microgram/kg). Piperazine determination was performed by HPLC of the dansylderivative after clean-up by TLC.

Administration, Oral↗
PubMed1986

[Anesthesia procedures and perioperative patient monitoring in chemonucleolysis].

Premedication with H1 and H2 blockers as well as cortisone to reduce or prevent allergic reactions should be an integral part of the overall treatment. The facilities for immediate treatment of anaphylactic reactions including cardiopulmonary resuscitation must be readily available. Our haemodynamic measurements allow us to give a negative answer to the question--so far not investigated in man--whether the use of chymopapain or of its fragments leads to constant cardiocirculatory effective reactions in the early phase. Our experiences collected so far favour catheter peridural anaesthesia as the method of choice in chemonucleolyses.

Anesthesia↗
PubMed1986

Reaggregates of cells from rat testis resemble developing gonads.

Reaggregates prepared from newborn rat testis cells in Moscona-type rotation cultures were analyzed and compared with normal fetal (12-21 days) and newborn testes at the light and electron microscope level. After 25 h of culture, the aggregates resembled normal testicular tissue. The cells of the surface layer were spindle-shaped and connected by adherent junctions. The epithelial cords were composed exclusively of Sertoli cells and were surrounded by elongated cells resembling the developing myoid cells in newborn testes. The basal aspect of the cords was covered by a layer of flocculent material which, in places, was organized like an ordinary basement membrane. Individual spermatogonia with pseudopodes were observed in the interstitial tissue. Some Leydig cells were organized into small clusters like those typical in newborn testes. The present observations indicate that, histologically, the reaggregation of separated testicular cells resembles the differentiation of embryonic male gonads.

Animals↗