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Biomedical subjects

M Strauss

Publications and source records attributed to M Strauss.

At least 235 records · Page 13Linked to original sources
PubMed1984

Ultrastructural study of the myocardial wall of the atrio-ventricular canal during the development of the embryonic chick heart.

In the early stages of chick embryo development (days 3-5) the myocardium of the atrio-ventricular canal (AV) is continuous with the atrial and ventricular muscles; however, interruption of muscular continuity is observed at later stages (from day 6 to day 8). The most relevant event occurring at the AV canal region is the dissociation of the myocytes due to the loss of their cellular attachments, rather than an invasion of connective tissue cells (endocardial and sub-epicardial) located on both sides of the myocardium. In this study, particular attention was paid to the sequential changes that take place in the myocardium of this region, these being (1) a reduction in the number of desmosomes and intercalated discs with the subsequent appearance of large, inter-cellular spaces between myocytes; (2) migration of these cells through a complex extra-cellular matrix, to which it appears to be closely related, suggesting that the macromolecules of this matrix may be being synthesized by the myocytes, and may take part in the process of cardiac cell separation; (3) incorporation of the myocytes in the developing tricuspid valve, where they co-exist with fibroblasts. The results of the study correspond remarkably well to those previously carried out on the left AV canal myocardium, suggesting that the behaviour of the muscle is the same, at all points around the AV canal.

Animals↗
PubMed1984

A well transformable E. coli tdk-strain--suitable for direct rescue of tk gene plasmids from mammalian cells.

An E. coli C600 tdk strain which is suitable for the direct rescue of the eukaryotic HSV-1 tk gene by functional selection in E. coli is described. This E. coli tdk mutant failed to grow on fluorouracil selection plates and showed values for thymidine kinase activity smaller than in the tdk negative KY 895 strain. It is genetically well transformable, i.e. the transformation efficiency with plasmid DNA from pSK1 amounts to 5 X 10(6) or 3 X 10(8) depending on the transformation procedure applied.

Escherichia coli↗
PubMed1984

Laryngeal carcinoma in childhood. Report of a case and review of the literature.

A rare case of an 81/2 year old boy with a stage III well differentiated squamous cell carcinoma of the larynx, which responded to chemotherapy and irradiation, is reported. It is the 56th case in children up to 15 years of age and 20th case in children 10 years old or younger reported since 1868. Carcinoma of the larynx in children has similar clinicopathological features to those of adult laryngeal carcinoma, but markedly differs as concerning sex incidence ratio. The main differential diagnosis is juvenile papillomatosis and the principal risk factor is previous cervical irradiation. Delayed diagnosis is frequent since clinical manifestations might be attributed to the normal laryngeal maturation process or to a common respiratory infection. Treatment is problematic, for special effort must be made to preserve laryngeal anatomy and function and to avoid complications. Prognosis of childhood laryngeal cancer is unclear since the reported survival rates are not tumor stage related.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Epstein-Barr virus antibody titers in cancer of the head and neck.

Pretreatment serum samples from 39 white American patients with epidermoid cancer of various sites of the head and neck, including the nasopharynx, were studied for both IgA and IgG antibodies to the Epstein-Barr virus (EBV)-specific antigens. Of the various serological assays, IgG anti-viral capsid antigen (VCA) was least specific and was present frequently at high titers in both the groups with nasopharyngeal carcinoma (NPC) and groups with other cancers (OC). The geometric mean titer (GMT) of IgA anti-VCA was significantly elevated in patients with NPC compared with the groups with OC. The incidence of this virologic parameter was high in the laryngeal and stage III and IV oral cavity groups of epidermoid cancer, and the GMTs were significantly greater than the control group. Finally, the GMTs of all the antibodies to the EBV-associated antigens were significantly elevated in patients with NPC who had regional metastases compared with those who had local disease with cranial nerve involvement.

Adolescent↗
PubMed1983

Cochlear aqueduct radiographic anatomy in temporal bone preparations and in sudden hearing loss.

Sudden sensorineural hearing loss appears to have many possible etiologic factors. Shea has presented work indicating that a large cochlear aqueduct (CA) is frequently present on the side of an idiopathic sudden sensorineural hearing loss (ISHL). However, Valvassori, on performing temporal bone tomographic studies on several hundred patients complaining of ISHL, has not found enlargement of the CA in a statistically significant number of these cases. In an attempt to resolve this discrepancy, a single blind study was performed utilizing temporal bone polytomography to evaluate the presence or absence of the CA in 22 adult patients. One-half of these patients had a history of ISHL, while the remaining patients had other complaints as an indication for tomography. In all cases, the CA was identified. The CA was felt to be enlarged in 1 patient suffering from ISHL, in the nonaffected ear of 1 patient with unilateral ISHL, and in 2 control patients. There was, therefore, no positive correlation between CA enlargement and the occurrence of ISHL. In order to further elucidate the radiologic anatomy of the CA, 9 pairs of adult temporal bones removed at autopsy were studied by polytomography after cannulation and injection of radiopaque material. Measurements of the dimensions of the CA and its radiographic anatomy are discussed and compared to measurements obtained from histopathologic evaluation of the temporal bone.

Adult↗
PubMed1983

Plasmids expressing the Herpes simplex virus thymidine kinase gene in mammalian and bacterial cells.

Two plasmids containing either the complete thymidine kinase gene of Herpes simplex virus type I (pSK2) or the gene without the remote control sequence (pSK1) just behind the lac promoter and the first codons of the lacZ gene were constructed. Both plasmids efficiently transform mouse Ltk- cells as well as E. coli tk- cells to the Tk+ phenotype and are well suited for plasmid rescue from transformed mouse cells by direct functional selection for tk expression using a tk- mutant of E. coli C600.

Escherichia coli↗
PubMed1983

Knotting and handling characteristics of coated synthetic absorbable sutures.

The purpose of this study was to evaluate the knotting and handling characteristics of the new coated synthetic absorbable sutures. When compared to the coated polyglactin 910 sutures, the coated polyglycolic acid sutures displayed a lower coefficient of friction, encountered less tissue drag forces, and exhibited less flexural rigidity. In the case of sizes O, 2-O, and 3-O coated polyglycolic sutures, knot security was achieved with one less throw than with similar sizes of coated polyglactin 910 sutures. On the basis of these comprehensive mechanical performance tests, the knotting and handling characteristics of the coated polyglycolic acid sutures were judged to be superior to that of the coated polyglactin 910 sutures.

Absorption↗
PubMed1983

New clinical applications of the stapedial reflex.

Stapedial reflex data were obtained from 11 myasthenic, 18 hyperthyroid and six hypothyroid patients. Data were studied with respect to reflex threshold, amplitude and decay. Elevated threshold, decreased amplitude, and high and low frequency reflex decay were observed in myasthenic and hyperthyroid patients. Hypothyroidism merely increases stapedial reflex amplitude but causes no significant threshold or decay changes.

Adult↗
PubMed1983

Malignant catecholamine-secreting carotid body paraganglioma.

The second known case of a malignant catecholamine-secreting (DA)-secreting carotid body paraganglioma is presented. Dopamine synthesis and secretion can be increased in malignant tumors derived from neural crest cells. Whether this is true, in addition, for extra-adrenal paragangliomas is not yet clear. Malignant paragangliomas of the carotid body and larynx, although rare, frequently have been accompanied by increased catecholamine secretion. Malignant catecholamine-secreting carotid body paragangliomas are best treated by composite resection (internal carotid artery and neck dissection), with special attention being given to measures preventing severe hypertension and arrhythmias in the perioperative period.

Adult↗
PubMed1983

Cis-platinum ototoxicity: clinical experience and temporal bone histopathology.

A clinical and pathologic study of cis-platinum ototoxicity was performed. Twenty-four patients treated with cis-platinum for head and neck cancer were studied prospectively. Post cis-platinum hearing losses were subclinical, detected in 25% of patients, isolated to 4 and 8 kHz, and did not exceed 25 dB at any frequency. Temporal bones from a 9-year-old with frontal lobe astrocytoma and with cis-platinum ototoxicity were studied with routine and special techniques to elucidate oto and neurotoxicity. Degenerative changes in the outer hair cells in the lower turns of the cochlea, in the spiral ganglion, and cochlear nerve were the most striking findings.

Adult↗
PubMed1983

The efficiency of genetic transformation of mammalian cells by transfection and microinjection depends on the transferred gene.

The efficiency of genetic transformation of mammalian cells was analysed with respect to the kind of the transferred gene and the selective system. Plasmids pAGO and pAG60 harboring the thymidine kinase gene of Herpes simplex virus type 1 and the bacterial neomycin resistance gene, respectively, were compared concerning their ability to transform mouse Ltk-aprt- cells. Using the calcium phosphate technique the neomycin resistance gene transformed at least ten times more efficiently than the thymidine kinase gene (3 X 10(-3) versus 2 X 10(-4] whereas the difference is even more impressive following microinjection of the plasmids into the nuclei (2 X 10(-1) versus 2.5 X 10(-3]. The neomycin system also proved to be more effective in secondary gene transfer experiments and, thus, seems to be the most convenient marker for cotransfer experiments.

Animals↗
PubMed1983

Coexistent carcinoma of the thyroid gland and Hashimoto's thyroiditis.

Three instances of Hashimoto's thyroiditis occurring in association with carcinoma of the thyroid gland are presented. Diagnosis was made by open surgical biopsy, revealing one papillary, one follicular and one mixed papillary-follicular carcinoma. Total thyroidectomy was performed and TSH suppressive therapy was administered postoperatively. All patients are alive with no evidence of local recurrence or distant metastases observed during five to 13 years of follow-up study. In our series, three of 18 patients had coexistent carcinoma of the thyroid gland and Hashimoto's disease. This figure is lower than the 25 per cent incidence of carcinoma of the thyroid gland in noninflammatory goiters observed at the same hospital. Although the number of patients is small, Hashimoto's thyroiditis does not seem to be a premalignant lesion and should not be treated by total thyroidectomy. A review of the literature points out that clinical, biochemical and radioactive scan findings in patients with Hashimoto's thyroiditis do not aid in differentiating between glands with or without coexistent carcinoma of the thyroid gland unless the goiter is uninodular and cold on the radioiodine scan. The prognosis of patients with carcinoma of the thyroid gland occurring in association with Hashimoto's disease is probably better than that of patients with carcinoma of the thyroid gland alone. It seems that the presence of the chronic inflammatory reaction may suppress growth and metastatic dissemination of the coexistent neoplasm of the thyroid gland.

Adenocarcinoma↗
PubMed1982

The DNA tumor virus SV 40 induces gene mutations in human cells. Reversion of HPRT deficiency.

The mutagenic effect of papovavirus SV40 on human cells could be demonstrated by reversion of HPRT deficiency in Lesch-Nyhan fibroblasts transformed by the virus. SV40 seems to induce different gene mutations in individually selected cell clones, as was clearly shown by the respective HPRT enzyme properties. The consequences of our results for use of SV40-derived vectors in gene substitution experiments are discussed.

Cell Transformation, Viral↗