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Biomedical subjects

C Thomas

Publications and source records attributed to C Thomas.

At least 541 records · Page 30Linked to original sources
PubMed1977

[Ultrastructural study on formal pathogenesis of experimentally induced rhabdomyosarcomas (author's transl)].

UNLABELLED: During oncogenesis the rhabdomyosarcomas pass different stages of differentiation. In experimentally induced rhabdomyosarcomas the chronological sequence of cytoplasmatic changes can be analysed. MATERIAL AND METHODS: 10 mg 9,10-dimethyl-1,2-benz-anthracene were injected subcutaneously or intramuscularly in the hind-paw of Wistar rats with 100 gms weight. 30, 60, 105, and 150 days later the animals were killed and specimens withdrawn. The soft-tissue was prepared for light- and electron-microscopy. RESULTS: In the soft-tissue tumors, experimentally produced with DMBA, 4 different cell types can be observed, which--depending on exposition time--dominate in the histological picture: (1) The myofibrillar cells. These cells are similar to rhabdomyocytes and contain numerous cytoplasmatic fibrillae with sarcomere-like structure. (2) The myofilamentous cells. These cells contain the fibrillar structure, but without sarcomere-like arrangement. (3) The undifferentiated sarcoma cells. These cells show a pathologically changed ergastoplasm and chondrioma. (4) The matured fibrosarcoma cells are nearly similar to fibrocytes. Under the cytoplasmatic changes especially the hyperplasia of the chondrioma can be observed, in which dystrophic megamitochondriae are found. These possibly reflect the abnormal glycolysis in cancer tissue. Also mitochondrial antibodies are discussed at the form pathogenesis of this change in organelles. Regarding the change of the endoplasmatic reticulu, the annulatae lamellae can be noticed which are typical for tumor cells. Furthermore megacisterns are found, in which protein-containing material is condensed as a consequence of a disturbed synthesis and secretion.

Animals↗
PubMed1976

[Hemorrhagic enteropathy].

Intestinal infarction in the absence of organic vascular occlusion received increasing attention in recent years. The clinical picture is discussed based on results in 9 cases, an attempt to suggest a possible pathophysiological mechanism is made. Prophylactic digitalisation especially in the elderly patient in the absence of severe heart failure and in cases with already low mesenteric perfusion may lead to a further vasoconstriction and to hemorrhagic enteropathy. Therapeutic possibilities are discussed.

Aged↗
PubMed1976

Transmission and scanning electron microscopy of experimentally induced thyroid tumors in rats.

Irradiation of the neck region of 10 days old Wistar rats with 300 rads X-rays and their subsequent treatment with MTU leads to the development of thyroid tumors. The ultrastructure of the thyroid tumors induced was studied by transmission (TEM) and scanning electron microscopy (SEM). In follicular carcinomas, cylindrical or high columnar cells with abundant microvilli, well-developed ergastoplasmic reticulum and a hypertrophied Golgi complex predominate. The cytoplasm of the tumor cells of papillary carcinomas was composed of large pleomorphic cisternae, irregular in shape mitochondria, dense bodies, phagolysosomes and lamellar or multivesicular structures. Scanning electron microscopy revealed in the control animals a regular pattern of thyroid follicles tied to each other by tissue bridges and covered by set of blood and lymph vessels. The relief of the follicular carcinomas was irregular indicating follicles different in size and shape. The internal surface of the neoplastic follicles was also irregular as result of deep invaginations and intrafollicular cell growth. The apical region of the normal and neoplastic thyroid follicular cells was covered with abundant microvilli protruding into the colloid.

Adenocarcinoma↗
PubMed1976

Large cerebral vessel disease in sickle cell anaemia.

An 18 year old male with documented sickle cell disease was admitted to the hospital for the final time in coma. Cerebral angiography revealed multiple stenotic lesions of the large cerebral vessels. The pathology of this large vessel involvement is demonstrated and the potential contribution of large as opposed to small cerebral vessel disease in the neurological manifestations of sickle cell anaemia is discussed.

Adolescent↗
PubMed1976

Effect of space factors on Escherichia coli B/r cells.

Stationary phase cells of Escherichia coli B/r were inactivated when they were exposed to high vacuum (10(-6) torr). About 5% of the cells were still able to form a colony after 45 min exposure. Vacuum dried cells (0.5 torr, 120 min) show colony forming ability of 30% or more. They were inactivated to about 5% by further vacuum treatment. Vacuum treated cells showed higher permeability for various cell components. UV irradiated E. coli B/r cells in vacuum showed increased UV sensitivity. DNA-protein cross-links were preferentially formed in a vacuum. To obtain 63% of DNA cross linked with protein required 852 erg mm-2 (D37) of UV irradiation in suspension and only 72 erg mm-2 of UV irradiation in vacuum. The protein components of DNA-protein cross-links were hydrolysed with pronase E and the amino acids directly bonding to DNA were determined. The most important amino acids concerned in DNA-protein cross-links seem to be glycine and alanine, followed by aspartic acid (asparagine), glutamic acid (glutamine) and histidine. The sensitivity to X-rays of stationary phase E. coli B/r cells seems to depend on the remaining gas atmospheric in the vacuum since it varies with different pumping systems.

Amino Acids↗