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Biomedical subjects

M Heinemann

Publications and source records attributed to M Heinemann.

At least 73 records · Page 4Linked to original sources
PubMed1987

[Ultraradical surgery of the shoulder and thoracic wall--indications and prognosis].

Super-radical surgery upon shoulder-girdle and chest wall often means mutilation and is therefore a heavy burden for the patient. Nevertheless it can have very rewarding results, if the indications are correct. They include treatment of soft tissue tumours, under certain conditions of metastases within the thoracic wall and very rarely of trauma. Experiences with 9 patients, treated between 1983 and 1985, are reported. Indications for these operations and their prognosis are discussed.

Adult↗
PubMed1986

[Mediastinal metastases of extrathoracic tumors--important findings in mediastinoscopy].

From 700 mediastinoscopies performed between 1976 and 1985, 11 revealed metastases from extrathoracic malignancies. Primary tumours were eventually located in the gastrointestinal tract (5), the breasts (2), the kidneys (2) and the thyroid gland (1). All lymphatics join within the mediastinum. Therefore mediastinal secondaries from tumours of all body regions may be encountered. Mediastinoscopy facilitates safe biopsy and histological diagnosis. It is essential for adequate therapy.

Adult↗
PubMed1982

[Possible mechanisms, differential diagnosis and prophylaxis of vocal cords palsy following endotracheal intubation].

This report is based on a total of 53 vocal cord palsies after endotracheal intubation on the basis of a bibliographical review and 5 of our own observations. Pressure and extension injuries of the recurrent laryngeal nerve, especially of its terminal branches, are probably the cause of such damage. It seems that infection of the respiratory tract encourage vocal cords palsies. Possible aetiological mechanisms and questions concerning the innervation of the larynx connected with this, the clinical differential diagnosis and prophylactic measures are discussed.

Diagnosis, Differential↗
PubMed1982

[Intralaryngeal struma].

This is the first report of an intralaryngeal struma in which particular case the thyroid tissue was connected with the extralaryngeal struma because of a defect in the thyroid cartilage below the beginning of the left vocal cord. Pathogenetically speaking, it cannot be fully explained how this could develop. Hypothetically, the thyroid tissue had already invaded the larynx before the median had fused with the lateral chondrification centers of the thyroid cartilage (before the 10th-13th embryonic week); later, in the course of the struma disease, the struma developed.

Diagnosis, Differential↗
PubMed1979

Initial site of insulin cleavage by insulin protease.

Exposure of insulin to insulin protease (insulinase, EC 3.4.22.11), a degradative enzyme with considerable specificity toward insulin, results in alterations in the properties of the insulin molecule. Limited degradation by the enzyme results in a decrease in the ability of insulin to bind to membrane receptors with less change in the immunoprecipitability or trichloracetic acid precipitability of the hormone. Limited degradation by insulin protease also alters insulin so that the molecule becomes susceptible to attack by nonspecific endopeptidases which have no effect on unaltered insulin. These data demonstrate the production of an intermediate in the proteolytic degradation of insulin. By labeling with [14C]dansyl chloride, an insulin intermediate with three amino-terminal residues, glycine, phenylalanine, and leucine, was identified. Analysis of this intermediate demonstrated that it was composed of an intact A chain and a B chain cleaved between residues B16 and B17, with the three peptide chains held together by disulfide bonds. Based on these findings, we hypothesize that a stepwise degradation of insulin occurs in vivo and that an early step in the process is the cleavage between B16 and B17 that renders the molecule sucseptible to further degradation by nonspecific proteases.

Amino Acid Sequence↗
PubMed1975

Proteolytic degradation of insulin and glucagon.

The degradation of insulin and glucagon by a highly purified enzyme isolated from rat skeletal muscle was investigated. A sensitive assay for proteolytic degradation of insulin and glucagon using fluorescamine to detect an increase in primary amine groups was established. As measured by an increase in fluorescamine reactive materials, insulin was rapidly degraded by this highly purified enzyme without requiring initial disulfide cleavage. Associated with the increase in fluorescamine reactive materials was a decrease in immunoassayable insulinmglucagon wal also proteolytically degraded by this enzyme but a number of other peptides and proteins including proinsulin, and A and B chains of insulin were not degraded. Thus, we have demonstrated that insulin (and glucagon) can be proteolytically degraded by an enzyme isolated from an insulin sensitive tissue, skeletal muscle. Proteolytic degradation by this enzyme requires the intact insulin molecule rather than separate A and B chains.

Animals↗
PubMed1971

Direct measurement of proinsulin in human plasma by the use of an insulin-degrading enzyme.

A method has been described for the direct measurement of proinsulin in human plasma. The method makes use of an insulin-degrading enzyme designated "insulin-specific protease (ISP)", which is obtained from rat skeletal muscle. Under the conditions used, this enzyme rapidly degrades insulin and insulin-like polypeptides to nonimmunoassayable components, whereas proinsulin and proinsulin cleaved at position B(54,55) are not appreciably affected. The incubation of plasma with ISP results in the disappearance of insulin, but not proinsulin, as demonstrated by column chromatography. Immunoassay of the plasma, therefore, before and after incubation, determines the values for the total immunoreactive substance (TIR) and for immunoreactive proinsulin (IRP), respectively. The values obtained for proinsulin levels are reproducible and compare closely with the more complicated column fractionation methods. Proinsulin responses were studied in four normal subjects and one patient with an insulinoma after a glucose load. Fasting proinsulin levels varied widely in the normal subjects, and the levels rose more slowly than TIR levels after glucose. IRP levels in the patient with an insulinoma were very high and fell to normal after removal of the tumor. The ISP method, therefore, appears to be suitable for the direct, accurate, and rapid determination of proinsulin and proinsulin-like materials in human plasma.

Adenoma, Islet Cell↗