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Biomedical subjects

J Schumann

Publications and source records attributed to J Schumann.

At least 73 records · Page 4Linked to original sources
PubMed1980

[Percutaneous extraction of gallstones by T-drainage (author's transl)].

Experience gained from the percutaneous extraction of biliary stones from 12 patients is reported. On three occasions the concrements could not be completely removed. A Zeiss sling proved more successful than a Dormia basket; with this it is not always necessary to use the guidable catheter. Conditions necessary for success are adequate thickness of the T-tube, and adequate time for the drainage (about three weeks) to permit the development of a track suitable for catheterisation. The method is so simple that it is recommended before an attempt is made to perform endoscopic extraction and papillotomy.

Catheterization↗
PubMed1980

Flow cytogenetics of uncloned and cloned Chinese hamster cells.

Flow cytometry has greatly facilitated the routine use of DNA content as a cellular indicator of the stages of the cell cycle and ploidy. DNA content can also be used to distinguish individual chromosomes. Fluorescent staining of chromosome DNA was done with a combination of ethidium bromide and mithramycin in hypotonic solution. Subsequent detergent treatment of the cells with Triton X-100 facilitated chromosome isolation. DNA flow cytometry of chromosomes of four established uncloned Chinese master cell lines showed 10 to 12 major subpopulations of chromosomes with varying degrees of overlap in the range of low and intermediate DNA content. Cloning of B14F28 cells, the line with the largest heterogeneity in chromosome number and DNA content, considerably reduced the dispersion in chromosome number and improved the resolution of DNA content distributions. Thus, cloned cells with a relatively homogeneous karyotype permit better discrimination of chromosome subpopulations by DNA content than uncloned cells and provide a more sensitive system to study mutagenic effects.

Animals↗
PubMed1980

Effects of acute gamma-irradiation on spermatogenesis as revealed by flow cytometry.

Mice irradiated with doses ranging from 0.1 to 15 Gy using a 60Co-source and controls were killed at intervals varying from 2 to 35 days after irradiation. The DNA content of the testicular cells in single cell suspensions was measured with the pulse cytophotometer to determine the frequencies of the different stages in the spermatogenesis. The relative amount of S-phase and 4c-cells was reduced initially but increased subsequently to hypernormal values. A decrease of 2c-cells indicated a higher cell-kill of diploid spermatogonia. Gamma ray-induced spermatids with abnormal DNA-values (diploid sperm) were identified. The results suggest that the spermatogenesis can be analysed with flow cytometry and used as a biologic dosimeter even for small doses of ionizing radiation.

Animals↗
PubMed1979

Flow cytometry of human spermatozoa.

Methods are given for the preparation and staining of human spermatozoa for flow cytometric DNA measurements. Using agents for the reductive cleavage of disulfide crosslinks and suitable proteolytic enzymes an effective decondensation of the sperm chromatin and a DNA-proportional uptake of fluorochromes is achieved. Thus reliable and precise measurements of the relative DNA content of human spermatozoa are possible and the two subpopulations of haploid spermatozoa can be distinguished according to the difference in their DNA content.

DNA↗
PubMed1979

[Pathogen elimination after surgical interventions on common bile duct (author's transl)].

Of 130 bile samples from the choledochus, 64% were positive for bacteria. Different antibiotics were administered according to the susceptibility tests. Colony counts were monitored daily. Beta-lactam antibiotics lead to a more rapid pathogen clearance than the tetracyclines. Antibiotic therapy is discussed especially in older patients and in patients with recurrent interventions on common bile duct. Bile cultures were positive in most of these patients.

Adult↗
PubMed1979

Cell-cycle phase-dependence of drug-induced cycle progression delay.

The effect of adriamycin on cell cycle phase progression of CHO cells synchronized into the various phases of the cell cycle by elutriation was investigated by high resolution pulse cytophotometry. Cells treated in all phases of the cell cycle showed delay in their subsequent progression. In addition to the wellknown block of cells in the G2-phase, a delay in passage of cells from G1 to S and a decreased rate of transit through the S-phase were observed. A broadening of the DNA distributions of the treated cells was observed after cell division indicating induction of chromosomal abnormalities.

Animals↗
PubMed1978

Studies on dispersed unincubated chick blastoderm cells. I. Early phases of aggregation.

Early phases of aggregation of dispersed unincubated chick blastoderm cells were investigated. Dispersed cells, when maintained in appropriate cultures, began adhering to one another almost immediately and eventually formed spherical aggregates without any recognizable structures except for occasional blood islands, after 24 hr of incubation. The number and size of aggregates derived from dispersed cells depended largely upon the speed of rotation and initial cell density. Treatment with colchicine (4 microgram/ml) had no apparent effect on adhesion of cells, although it yielded smaller aggregates than controls, especially after 14 hr of incubation. Direct observation on mitotic activity, estimations of cell number and nucleic acid content, and pulse labeling experiments with 3H thymidine clearly showed that aggregates were derived entirely from adhesion of free cells and/or fusion of smaller aggregates during the first 12 to 13 hr of incubation. In addition, all cell types present in the unincubated blastoderm contributed to the formation of aggregates, not one particular cell type.

Animals↗
PubMed1978

[Postoperative anastomotic stenosis after anterior resection of the sigmoid colon and rectum (author's transl)].

149 patients underwent anterior resection of the sigmoid colon and the rectum with decompression-transverse colostomy. In 10 cases stenosis of the anastomosis was observed. The development of the stenosis is believed to have been caused by a small leak in the anastomosis, leading to secondary bacterial infection and hence scar formation. It is suggested that a one layer through and through silk suture promotes the eventual stenosis.

Cicatrix↗
PubMed1978

[Invagination of the blind loop--a complication after jejuno-ileal shunting (author's transl)].

Shunting of the jejunum and ileum has been used as a form of therapy in extreme obesity; this may be followed not only by metabolic, but also by surgical complications. A case report is given of a patient, who had an invagination of the excluded segment of the small intestine. Diagnostic difficulties and dangers arising from this complication are discussed as well as surgical techniques allowing to avoid it.

Female↗
PubMed1977

DNA-fluorometry of mammalian sperm.

The Dna-content of sperm and testicular cells was measured by pulse-cytophotometry with high resolution. From flat sperm symmetric and narrow fluorescene distributions were obtained. Enzymatic treatment with papain or pronase and staining with an ethidiumbromide-mithramycin dye solution generate stoichiometric DNA-staining including that of mature sperm with a coefficient of variation below 2%.

Animals↗
PubMed1977

[The medullary (C-cell) carcinoma of the thyroid. A therapeutic dilemma].

Medullary carcinoma originates from the parafollicular cells (C-cells) of the thyroid. Significant for these cancers are early metastases in thyroid and in the regional lymph nodes. Total thyroidectomy combined with local excision of any palpable metastases is the procedure of choice. Radioiodine therapy of metastases as in papillary and follicular carcinoma is not possible because C-cells do not metabolise iodine. This tumor is also resistant on X-ray therapy. Follow-up and early diagnosis of medullary carcinoma is possible by determination of calcitonin in serum. The local recurrence or metastases in lymph nodes should be surgically removed.

Adult↗