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Biomedical subjects

U Friedrich

Publications and source records attributed to U Friedrich.

At least 127 records · Page 7Linked to original sources
PubMed1979

Origin of triploidy in spontaneous abortuses.

Fourteen triploid spontaneous abortuses were studied cytogenetically by sequential Q and C banding and the marker chromosomes were compared with those of the parents. The abortuses comprised all triploid cases in a series of 288 consecutive abortuses of the first 16 weeks of pregnancy occurring in one hospital. In 12 of the triploids the origin of the extra haploid set was conclusively determined, revealing six cases of dispermy, five failures in the first maternal and one failure in the first paternal meiotic division. The results were combined with those of five other studies comprising a total of 48 informative cases. Non-reduction in the second meiotic division seems to be of little or no significance in the origin of human triploidy. Dispermy is the predominant source, accounting for 40--50% of the triploid spontaneous abortuses. Non-reduction in the first meiotic division of the father seems to be the second-most frequent source although in the present material the corresponding maternal non-reduction is much more common.

Abortion, Spontaneous↗
PubMed1978

Small metacentric nonsatellited extra chromosome: report of five mentally retarded individuals and review of literature. Contribution to further delineation of a new syndrome.

Five mentally retarded male patients with a supernumerary small metacentric nonsatellited chromosome were found to have many clinical features in common. The face showed characteristic small crowded features, the bodily habitus was asthenic, and the hands and feet had minor abnormalities. Renal anomalies were present in two patients. One patient had a myelomeningocele. Cytogenetic studies employing Q, R, and C banding in four patients showed the small extra chromosome to have staining properties compatible with an isochromosome of the short arm of chromosome 18. A comparison with previous case reports suggests a new syndrome. However, the identity of the extra chromosome has not yet been determined.

Adolescent↗
PubMed1978

[Intestinal hemorrhage in Klippel-Trenaunay syndrome].

It is reported on a 21-year-old patient with Klippel-Trenaunay's syndrome and simultaneous intestinal haemorrhage. Anamnesis and histological findings are discussed and the problems of therapy are explained. In the discussion the knowledge of the peripheral angiodysplasias and their differential diagnosis in literature are entered. Comparative considerations concerning the own case are made.

Adult↗
PubMed1978

[Hemangioendothelioma--a case contribution].

By means of two casuistics the haemangioendothelioma is demonstrated. The malignant tumour may occur in all tissues and organs metastasizing in haematogenic and lymphogenic manners. The thorotrast or vinylchloride-caused promotion of the tumour formation is especially discussed because of its considerably prophylactic importance.

Adrenal Gland Neoplasms↗
PubMed1978

[The abrasion of amalgam and composites in the lateral dental region].

In 41 patients class 11 cavities each of the lower jaw were filled with the materials Adaptic, Concise cap, Epoxydent or amalgam. The models made from impressions were systemically measured by a coordinate measuring machine according to a procedure determined by us (measuring error of this method about 15 micron). After one year the following abrasions were found: amalgam 18 micron +/- 58 micron, Adaptic 92 micron +/- 97 micron, Concise Cap 146 micron +/- 75 micron, Epoxydent 38 micron +/- 50 micron. Evaluation of the clinical examination showed that the materials Concise and Epoxydent were significantly inferior as regards border closure than amalgam and Adaptic. We determined further that a large percentage of composite filling showed visible discoloration of the borders (Adaptic 42%, Concise 55%, Epoxydent 80%). Many of the fillings were discolored after a year. Adaptic was highly significantly different with 31.6% discolored fillings to both other materials (Concise 79%, Epoxydent 78.4%).

Bicuspid↗
PubMed1978

[The abrasion of amalgam and composites in the area of the lateral teeth].

Four materials: amalgam, Epoxydent, Adaptic and concise Cap were filled after certain criteria into class II mandibular cavities and examined after one year. The very accurate models were submitted to measuring with a three-dimensional measuring device. The results were the following: amalgam 18 +/- 58 micron Epoxydent 38 +/- 50 micron Adaptic 92 +/- 97 micron Concise Cap 146 +/- 75 micron Only the first difference between amalgam and Epoxydent is statistically insignificant, the others are all relevant. Furthermore, a mean abrasion of functional cusps of 70 micron and a maximum abrasion of 300 micron could be observed. Clinically, relative to marginal adaptation and discoloration, Adaptic was clearly superior to the other two composites. Class II cavities must routinely be restored with amalgam, and composite "streets" must be strictly avoided.

Adolescent↗
PubMed1977

Hypoxanthine-guanine phosphoribosyl transferase with altered substrate affinity in mutant mouse lymphoma cells.

Cells with altered hypoxanthine-guanine phosphoribosyl transferase (HPRT) (IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) have been selected. Compared to wild type, mutant enzyme has a reduced affinity for the substrate phosphoribosyl pyrophosphate and is more labile to heat inactivation. Mutant cells are resistant to 6-thioguanine at 33-39 degrees C and sensitive to hypoxanthine-aminopterin-thymidine at 37-39 degrees C, but not at 33 degrees C. We hypothesize that a single structural mutation of HPRT can explain these results.

Aminopterin↗
PubMed1977

[Triploidy].

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Female↗
PubMed1977

Mutations causing charge alterations in regulatory subunits of the cAMP-dependent protein kinase of cultured S49 lymphoma cells.

Two-dimensional polyacrylamide gel electrophoresis is used to visualize the regulatory subunit of cAMP-dependent protein kinase from cultured S49 mouse lymphoma cells and to demonstrate its in vivo phosphorylation. Regulatory subunits from mutant cells with altered kinases exhibit at least two patterns of charge shifts consistent with substitutions of single amino acids. The direct demonstration of structural alteration of this protein provides strong evidence for structural gene mutation in this cultured cell system. While mutant and wild-type gene products co-exist in the mutant cells, there is apparently preferential expression and phosphorylation of mutant subunit in these heterozygotes.

Cell Line↗
PubMed1977

Mutagenesis in S49 mouse lymphoma cells: induction of resistance to ouabain, 6-thioguanine, and dibutyryl cyclic AMP.

The effects of mutagens on three genetic markers--resistance to ouabain, 6-thioguanine, and dibutyryl cyclic AMP (Bt2cAMP), were investigated in a mouse lymphoma cell line, S49. Nitrosoguanidine, ethyl methanesulfonate, ICR 191, and x-rays were used. Mutagen-specific responses were seen. Ouabain resistance was induced by nitrosoguanidine, but not by ICR 191. ICR 191 induced resistance to 6-thioguanine more efficiently than did nitrosoguanidine; the converse was true of resistance to Bt2cAMP. The relative frequency of biochemically distinguishable subtypes of mutants resistant to Bt2cAMP was characteristic of the mutagen used to generate them. The results can be interpreted as follows: nitrosoguanidine and ethyl methanesulfonate frequently, but ICR 191 and x-rays rarely, give rise to DNA base sequence changes that result in structurally altered but functional proteins. This type of change is required for induction of mutants resistant to ouabain and of certain classes of mutants resistant to Bt2cAMP. Resistance to 6-thioguanine and other classes of mutants resistant to Bt2cAMP can result from DNA base sequence changes that lead to extensive alteration of protein structure or expression; these changes are induced by ICR 191 or x-rays.

Bucladesine↗
PubMed1976

Origin of the extra chromosome in trisomy 16.

Chromosome analysis was carried out on 22 spontaneous abortuses with trisomy 16 and their parents by means of sequential Q- and C-banding techniques. In seven cases, the extra chromosome No. 16 originated from a non-disjunctional error in the first meiotic division in the mother, and in two cases from an error in the first meiotic division in the father. In two cases, non-disjunction had occurred during the second meiotic division (one in the mother and one in the father). It seems that trisomy 16, although independent of maternal age, most frequently results from a first meiotic non-disjunction in the mother.

Abortion, Spontaneous↗