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Biomedical subjects

J Schumann

Publications and source records attributed to J Schumann.

At least 19 recordsLinked to original sources

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

[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

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

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

[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

[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

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

[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

[Experimental examinations about the proliferation and radiotherapy after administration of Vincristin and Adriamycin (author's transl)].

Cytophotometric examinations of solid carcinomas of Ehrlich in mice don't show a considerable cyto-cinetic effect after administration of Vincristin. On the other hand, Adriamycin causes in the same tumor a significant stop in the G2 + M phase with a synchronization factor of 1,4 to 1,5 related to G2. The following experiment with the combined Adriamycin and radiotherapy demonstrates with a statistical significance lying about 5% that an immediate radiotherapeutic success can be obtained which is even increased by a partial synchronization. A considerably enriched G2 + M phase as a result of the administration of Adriamyzin is proven by a first cyto-cinetic examination of human cancerous tissue. A possible clinical therapy scheme is discussed.

Animals

[The effect of bencyclane hydrogen fumarate (Fludilate) on the adhesion of tumor cells in vivo and in vitro].

Bencyclane hydrogen fumarate (Fludilat) was tested on the stickiness of tumor cells in vivo and in vitro. It was intended to determine whether Fludilat reduced the cancer cell stickiness in vitro, and if the survival time of cancer cell carrying animals can be increased with Fludilat in vivo, or in combination with a cytostatic. For the in vitro trials, concentrations from 0.001 mg/ml to 1 mg/ml medium were chosen. The survival trial on NMRI-mice with Nemeth-Kellner lymphosarcoma was performed in three groups, each with 4-5 sub-groups: Control group--Fludilat 5 mg, 10 mg, 20 mg/kg bodyweight, Bleomycin--50 mg/kg bodyweight, 100 mg/kg bodyweight, 250 mg/kg bodyweight, Bleomycin 50 mg/kg bodyweight + Fludilat 5 mg/kg bodyweight, Bleomycin 100 mg/kg + Fludilat 10 mg/kg bodyweight, Bleomycin 250 mg/kg + Fludilat 20 mg/kg bodyweight. The sequence of deaths was determined, and the 50% survival time was taken as criterium for the effect of the treatment. The in vitro trials showed a complete removal of the monolayer of the tumor cells from the bottom of the culture flask, in doses of 0.01-1 mg/ml medium. In the in vivo trial an increase in the 50% survival time could be achieved in all groups. The results of combined therapy of Fludilat and Bleomycin were striking. In comparison to the control animals, the treated animals showed that the occurrence of solid abdominal metastases from the Nemeth-Kellner lymphosarcoma could be almost completely prevented, especially at high doses. The Ca++-antagonistic effect, in changing the surface of the cells, is discussed as a mechanism of action.

Animals

Irradiation treatment of inoperable squamous cell carcinomas of the oral cavity and oropharynx after partial synchronisation.

Bleomycin has proved to be an efficacious cyclus-synchronising drug in the sense that it arrests the radiosensitive G2-phase directly. In comparison with 5-Fluor-uracil, Bleomycin possesses a more effective cell-kinetics. An analytical clinical remission with the application of Bleomycin, coupled with a higher incidence of local and general side effects.

Bleomycin