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Biomedical subjects

W Schmid

Publications and source records attributed to W Schmid.

At least 181 records · Page 10Linked to original sources

[Further investigations into the effectiveness of gentamicin and other antibiotics against urinary tract infection organisms (author's transl)].

In continuance of our investigations from 1968 to 1972, we isolated 32939 microorganisms from urinary tract infections and subjected them to routine sensitivity tests against six antibiotics from 1973 to August 1975. All organisms except enterococci and proteus proved to be sensitive to gentamicin at a level exceeding 90% during the study period of two and a half years. A loss of activity of gentamicin worth mentioning was not detected during the studies. So this antibiotic must further be considered as one of the drugs of first choice in the treatment of urinary tract infections.

Alcaligenes↗

[The Sézary syndrome].

A case of the rare Sézary syndrome is described. The Sézary syndrome is a lymphoproliferative disorder of the skin, the lymph nodes, and to a smaller extent the bone marrow, which begins with erythrodermia. In the blood, strange circulating lymphocytes with a "cerebriform" chromatin structure and T-cell properties are found. The disease is primarly benign but may become malignant. The origin is unknown. Endogenic and exogenic factors are considered and relationships to other cutaneous lympho-proliferative diseases and treatment are discussed.

Chlorambucil↗

Further delineation of the clinical picture of trisomy for the distal segment of chromosome 13: report of three cases.

Three cases of partial trisomy for the distal segment of chromosome 13 are reported. Common clinical features included normal birth weight, postnatal asphyxia, convulsions, severe psychomotor retardation, normal growth, and a distinct pattern of dysmorphias consisting of trigonocephalic head with prominent metopic suture, long and markedly curved eyelashes, a stubby nose, increased distance between nose and upper lip, high-arched palate, misshapen ears with virtually absent lobules and prominent anthelices which are curved in a sharp angle, and hemangiomata. Features present in 2 cases were microcephaly, long and narrow fingers with convex nails, and hexadactyly. Two cousins were unbalanced offspring of a large family of carriers of a 9/13 translocation, whereas the third case exhibited a 13p+ chromosome which was formed de novo. The clinical features in the 3 patients are typical of the syndrome due to partial trisomy for the distal segment of chromosome 13 which shows selected and mitigated signs of full trisomy 13.

Abnormalities, Multiple↗

Lymphocyte chromosome studies in humans exposed to chemical mutagens. The validity of the method in 67 patients under cytostatic therapy.

Eighty-three lymphocyte cultures from 67 patients exposed to high therapeutic doses of chemical mutagens and from 10 healthy controls were examined for structural aberrations of the chromatid type (gaps, breaks and exchanges) and chromosome type (rings, dicentrics, acentric fragments and abnormal chromosomes) in order to evaluate the reliability of this testing system. Most of the patients had received several drugs; a few had radiotherapy as well. Owing to insufficient yields of mitoses at shorter incubation periods a culture time of 72 h had to be chosen. Whenever possible, 100 mitoses were analyzed. Because evaluation is highly subjective, gaps (i.e. interruptions of the chromatid structure not clearly exceeding a chromatid's width) were not included in the results. The incidence of chromatid breaks was 0--2% in the controls and 0--4% in most of the patients. In 6 cases containing 5--15% mitoses with chromatid breaks and exchanges, these values did not correlate with increased incidences of chromosome type aberrations. The incidence of chromosome type aberrations was 0--1% in the controls as well as in 19/20 patients who had received anti-metabolites and spindle poisons only and in 22/53 patients who had received therapeutic irradiation and/or well-known clastogenic agents. From these findings it is concluded that an increased incidence of chromatid breaks and exchanges is not a typical finding in lymphocyte cultures of persons exposed in vivo to chromosome breaking agents, and that a normal incidence of chromosome type aberrations does not exclude exposure to massive doses of clastogens. This testing system is therefore judged to be inadequate for monitoring weak or questionable mutagens in exposed populations.

Adolescent↗

Ten model mutagens evaluated by the micronucleus test.

The following ten mutagenic compounds were subjected to the micronucleus bone marrow test (MNT) in the mouse: cyclophosphamide (CTX), thiotepa (TT), vincristin (VCR), colcemid (COLC), adriamycin (AM), bleomycin (BM), cytosin arabinoside (ARA C), 6-mercaptopurine (6-MP), methotrexate (MTX) and 5-fluorouracil (5-FU). Dose-effect curves were established for all compounds. With the exception of CTX, COLC and AM, the drugs also were subjected to chromosome analyses on Chinese hamster fibroblasts in vitro. The MNT revealed loss of chromatin due to chromosome breakage and rearrangements by CTX, TT and AM, to breakage by ARA C, 6-MP, MTX and 5-FU, as well as loss of entire chromosomes caused by impairment of the spindle by VCR and COLC. With the exception of BM, the effects were demonstrable in the therapeutic dose range. The MNT, provided it is carried out by the methodology of the authors, not only reveals chromatin loss but permits important conclusions in regard to the proliferative state of the bone marrow and the specific time of action of the mutagens in the cell cycle. If arrest of the cell cycle occurs, as in the case of anti-metabolites MTX and 5-FU particularly, the routine scheme of investigation needs to be modified since micronucleated cells appear only after release of the metabolic block, i.e. after a delay of 24 h. The negative bone marrow results obtained with BM emphasize the importance of combining in vivo and in vitro tests.

Animals↗

Christmas disease (haemophilia B) in a girl with deletion of the short arm of one X-chromosome (functional Turner syndrome).

A I-year-old girl with severe Christmas disease and a factor IX content less than I% of normal is described. The family history was negative and coagulation studies on her relatives were normal. Genetic investigation showed an XXp-karyotype with deletion of the short arm of one X-chromosome, a cytogenetic variant of Turner syndrome. The transmission pathway of the haemophilia gene is discussed.

Chromosome Aberrations↗

Trisomy 9p due to paternal translocation, t(9;13) (q13;q12).

A 16-year-old girl with trisomy 9p is described. She had a short stature, severe mental retardation and the following abnormal clinical findings: peculiar face with hypertelorism, downward slanting palpebral fissures, convergent strabismus, a bulbous nose with broad and prominent bridge, short upper lip, narrow, high-arched palate; short neck with low hairline; severe kyphoscoliosis and a congenital clubfoot deformity; hypoplasia and dysplasia of several phalanges of the fingers and toes and some nails, a delay by about 6 years in bone age, and remarkable dermatoglyphic patterns. The father and 3 other family members carried a balanced translocation between chromosomes 9 and 13, t(9;13)(q13;q12).

Abnormalities, Multiple↗

A technique for in situ karyotyping of primary amniotic fluid cell cultures.

A time proven technique is described for growing amniotic fluid cell cultures on cover glasses in Leighton tubes and for processing the mitotic cells in situ. Karyotyping the clones in situ eliminates most of the problems caused by somatic chromosome mutations in vitro and by maternal cell growth.

Amniocentesis↗

[First experiences with amniocentesis from genetic indications].

Genetically indicated amniocentesis was performed in 93 patients in the first half of pregnancy and in 36 in the second half. To the common and recognized indications several obstetric indications were added. Six (4.7%) fetal abnormalities were diagnosed by karyotyping and determination of alpha1-fetoprotein (AFP), i.e. a child with trisomy 21 and a boy with XXY Klinefelter syndrome, both in mothers aged over 40, a partial trisomy 3 in a pregnancy with a balanced anomaly, 2 boys with X-linked hereditary disease and an anencephalic. In 4 cases (3.1) abortion was performed at the parents' request. Three pregnancies ended in spontaneous abortion. In 54 cases in which amniocentesis was performed in the first half of pregnancy the babies have now been born. One was found to have a congenital heart defect and the remainder were healthy. In the cases which had undergone genetic screening during the second half of pregnancy 3 neonates displayed anomalies not detectable by karyotyping or AFP determination, one of which was hydrocephalus. The abortion rate was 0.8%.

Anencephaly↗

Tandem duplication q14 and dicentric formation by end-to-end chromosome fusions in ataxia telandiectasia (AT). Clinical and cytogenetic findings in 5 patients.

Chromosome studies on lymphocyte cultures were performed in 5 patients with AT, 2 of whom had been followed for 4 years. Four out of these patients showed an increased incidence of chromosome-type aberrations. A clonal development was present in one patient, 96% of his metaphases containing a tandem duplication of almost the entire long arm 14. Four years earlier the proportion of these cells was 80%. Two other patients presented a small proportion of cells with an unidentified abnormally long D chromosome. In a total of 724 metaphases from 4 patients 31 dicentric chromosomes were observed, all of a peculiar type; in their formation no chromosome material was lost and they all seem to have arisen by end-to-end fusions. The incidence of chromatid-type aberrations was normal or at the upper limit of control values in all 5 cases. The sister chromatid exchange rate studied with BUDR in 3 patients was found to be normal.

Adolescent↗

The rate of sister chromatid exchanges parallel to spontaneous chromosome breakage in Fanconi's anemia and to trenimon-induced aberrations in human lymphocytes and fibroblasts.

The incidence of structural chromosome aberrations and the rate of sister chromatid exchanges (SCE) was investigated in lymphocyte cultures from a patient with typical Fanconi's anemia and his parents. The rate of SCEs was found to be normal. In experiments with the alkylating agent Trenimon the SCE rates proved to be a sensitive indicator for the induction of structural aberrations: in presence of an induced aberration rate half as high as the spontaneous rate in the Fanconi's anemia case, the rate of SCEs was found to be quintupled. Dose-effect relationships for the induction of SCE rates by Trenimon were studied over a wide dose range in lymphocyte and fibroblast cultures. The results reflect the same difference in sensitivity earlier observed in the induction of structural chromosome aberrations, fibroblasts being far more sensitive.

Anemia, Aplastic↗

Nucleolar RNA synthesis in the liver of partially hepatectomized and cortisol-treated rats.

RNA synthesis by isolated nucleoli from rat liver is significantly enhanced 12--14 h after partial hepatectomy and 4 h after cortisol administration. The increased RNA synthetic capactiy is demonstrable also in the respective high salt nucleolar extracts and in Biogel A-1.5 filtration fractions of the nucleolar extracts. DNA saturation experiments using nucleoli and Biogel fractions from control and treated animals as RNA polymerase source, have demonstrated, that independent of the extent of RNA synthesis, saturation of transcription is reached at the same concentration of exogenous template. We conclude that the activity and not the amount of nucleolar RNA polymerase is increased as a result of partial hepatectomy or cortisol administration. Parallel to the effects on RNA polymerase, the activity, of RNA-degrading enzymes present in nucleoli is also enhanced by the same treatment.

Animals↗

Ring chromosome 13 in a polymalformed anencephalic.

In the 33rd week of pregnancy an amniocentesis was performed because of low estriol. X-ray indicated the presence of anencephaly and a premature delivery was induced. Necropsy, in addition to anencephaly, showed a wide variety of malformations. The fetal karyotype determined from cultured amniotic fluid cells revealed a ring chromosome 13.

Abnormalities, Multiple↗

High amniotic fluid alpha-1-fetoprotein in a case of fetal sacrococcygeal teratoma.

Amniocentesis was performed in a pregnancy of 26 weeks because of hydramnios. The amniotic fluid was examined for fetal karyotype and AFP content. The latter was elevated to 300 mug/ml. Fetal death occurred shortly after amniocentesis and a malformed male fetus with a large sacrococcygeal teratoma was stillborn 3 days later.

Alpha-Globulins↗

[Triploidy as a cause of midtrimester gestosis(author's transl)].

The authors report a case of triploidy in a prematurely born child. The pregnancy was complicated by severe toxemia beginning during the second trimester and terminating in preeclampsia leading to cesarian section in the 33th week of gestation. The externally female child was underweight, hypotonic and asphyctic and died shortly after birth. She exhibited a complex brain malformation including excessive hydrocephaly, cebocephaly and aplasia of the piturary gland, and multiple dysmorphic signs. Autopsy revealed hypoplasia and dysplasia of the adrenal glands; no uterus, tubes and ovaries were present, but no testes were found. The placenta showed localized hydatidiform degeneration and was relatively large. The karyotype was 69,XXY, and with the aid of fluorescence markers, paternal origin of the additional haploid chromosome set was demonstrated. Typical findings in pregnancies with fetal triploidy are discussed and the possibility of prenatal diagnosis of triploidy by chromosome analysis in cultivated amniotic fluid cells is pointed out.

Abnormalities, Multiple↗