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Biomedical subjects

C Beck

Publications and source records attributed to C Beck.

At least 181 records · Page 10Linked to original sources
PubMed1982

Only one gene is required for the glpT-dependent transport of sn-glycerol-3-phosphate in Escherichia coli.

Deletion and point mutants defective in the glpT-dependent sn-glycerol-3-phosphate transport system were isolated and located on the Escherichia coli chromosome. They mapped in glpT in the clockwise order gyrA, glpA, glpT at around 48 min on the Escherichia coli linkage map. The mutations within glpT were ordered by deletion mapping, three factor crosses, and by crosses involving lambda transducing bacteriophages carrying glpT-lac operon fusions. Results obtained using these fusion phages indicated that glpT is transcribed in the counterclockwise direction on the E. coli linkage map. Complementation analysis using these mutants revealed only one complementation group. Thus, one gene is necessary and sufficient for the proton motive force-dependent sn-glycerol-3-phosphate transport system.

Biological Transport↗
PubMed1982

Interstitial radiotherapy with 198Au seeds in the primary management of carcinoma of the oral tongue: results in Freiburg/Breisgau from January 1964 to July 1980.

Thirty-two patients with histologically proven carcinoma of the oral tongue, Stage T1-3, were analyzed retrospectively. They were treated from January 1964 through July 1980 in Freiburg by interstitial implantation with Au-198-seeds for the primary tumor management. Out of 25 patients with complete follow-up, one patient developed a local recurrence. In three patients, regional lymph node metastases occurred, once after prior adjuvant radiotherapy to the regional lymph nodes area, and in two patients after exclusive interstitial radiotherapy to the tumor of the tongue. The overall five-year survival rate was 52% for all stages (overall group), 75% for Stage T1 and 44% for Stages T2-3. The corrected five-year survival rate was 75% for all stages, 86% for Stage T1 and 71% for Stages T2-3. The method of 198Au-seed implantation as it is practiced in Freiburg is discussed, as well as the radiation exposure of the personnel.

Adult↗
PubMed1982

[Sandwich irradiation of patients with squamous cell carcinoma of the tonsil, the base of the tongue and the hypopharynx].

Taking into account the death rate of all other causes for that age group and comparing the survival time and the recurrence rate in patients with preoperative short-time irradiation with telecobalt 60 and a focal dose of 20 Gy with a second group of patients treated with postoperative radiotherapy, we were unable to detect any advantage of the so-called "sandwich therapy" in cancer of the tonsils, the base of the tongue or the hypopharynx. On the contrary: patients with "sandwich therapy" had to be hospitalized longer because of the interval between preoperative radiotherapy and surgery and because of the delay in restoring postoperative speech and deglutition.

Carcinoma, Squamous Cell↗
PubMed1982

[Are porous tricalcium phosphate ceramics suited for the replacement of bony walls in ear surgery? An animal experiment study of the hypotympanum of the domestic swine].

The purpose of this study was to examine the possibility of a partially or totally posterior canal and lateral attic wall reconstruction with a more stable and therefore less porous tricalcium phosphate ceramic plate (S8). The hypotympanon of 4 pigs was drilled out, leaving the bony shell intact. In the middle part of this cavity a 2 mm thick S8-ceramic plate was placed horizontally. The hypotympanon of further 11 pigs was drilled out and obliterated with a more porous tricalcium phosphate ceramic (S5). Additionally, a single S8 ceramic plate served as a wall to the cavum tympani. 1 to 18 months after operation the pigs were sacrificed; sections of the hypotympanon were investigated with light microscopy. After few weeks, the S8-ceramic plate was covered by granulation tissue and epithelium on the tympanic side. After three months newly formed bony tissue could be observed between the peripheral parts of the S8-ceramic plate and the tympanic epithelium. After six months both sides of the S8-ceramic plate were completely covered by new bone; moreover this bone is covered by the mucosa on the tympanic side. At this time the S8-ceramic plate has a tight bony contact to the shell of the hypotympanon and bone growth can be observed in the macropores of this plate. The bony layer on the tympanic side of the S8-ceramic plate remained slim, there was no exophytic growth after 12 months. After 18 months the S8-ceramic plate shows distinct signs of resorption and bony replacement. However, in comparison to the S5-ceramic this occurs slower and later.

Animals↗
PubMed1981

A contribution to the pathogenesis of cholesteatoma. A histochemical and ultrastructural study.

In a histochemical and ultrastructural study the pathogenesis of cholesteatoma ostitis is analysed on human tissue. In the subepithelial layer there is evidence of an inflammatory reaction leading to proliferation of granulation tissue with bony invasion. Bony destruction is initiated by osteocytic osteolysis. In the case of cholesteatoma there is a combined action of extraosseous and osseous lysosomal enzymes. The pathological changes of the fibrillar elements suggest that the self-perpetuation of degeneration is maintained by a disturbance of fibrillogenesis. The causal pathogenesis of cholesteatoma formation is discussed as a function of a disturbance between cellular activity, extracellular matrix, and cellular surface.

Cholesteatoma↗
PubMed1981

[The origin of efferent fibers to the inner ear on reptiles. A HRP study in Caiman crocodilus (author's transl)].

The origin of efferent fibers to the inner ear was studied in Caiman crocodilus. After injection of horseradish peroxidase into the basilar papilla or into the ampullae of the horizontal and anterior semicircular canals, neurons labeled by the granular reaction product of retrogradely transported HRP were found in the medulla oblongata bilaterally. Parent cells of the efferent cochlear bundle were found in the medial reticular nucleus and in the rostroventral division of the superior olive bilaterally. Efferent vestibular neurons were found in the medial reticular nucleus bilaterally with more neurons ipsilateral to the injection site.

Alligators and Crocodiles↗
PubMed1981

[The auditory pathway in guinea pigs. A [14C]2-deoxyglucose study (author's transl)].

The auditory pathway of guinea pigs was labeled with [14C]-deoxyglucose after mon- or binaural stimulation with farfield white noise in a sound-proof chamber. In the autoradiographs, all auditory nuclei were labeled. The highest metabolic effects were seen in the dorsal cochlear nucleus, the lateral superior olivary nucleus, and in the inferior colliculus. No selective labeling was observed in the auditory cortex. Monaural stimulation depressed the metabolic activity contralaterally in the ventral cochlear nucleus and ipsilaterally in the medial nucleus of the trapezoid body, the dorsomedial periolivary nucleus, and in the inferior colliculus.

Acoustic Stimulation↗
PubMed1981

[Second generation of absorbable suture material. Tissue reaction and indication (author's transl)].

Polyglycolic acid (PGA) sutures have proved to be superior than other, nonabsorbable suture materials: a higher traction capacity and knot-tearing security, a defined and nearly linear decrease of traction capacity, no immunological reactions, very little capillarity, minimal tissue reaction, nearly no scar formation, and a bactericidal effect. PGA sutures of the second generation have the same advantages, but surgical handling is so much improved that they may be technically employed in unfavorable locations. In the surgery of gastrointestinal tract and respiratory organs there is a trend to connect all layers with one suture.

Absorption↗
PubMed1981

[Cholesteatoma, oto- and tympanosclerosis: their general mechanism of tissue destruction (author's transl)].

The connective tissue contains extracellular enzymes for the turnover of the ground substance. If this enzyme system gets out of control there is development of a complex metabolic disturbance of all tissue components. The lysosomal dysfunction is the basis of the general mechanism of tissue destruction in cholesteatoma, oto- and tympanosclerosis. This process seems most enhanced in cholesteatoma. Emphasis is placed on the role of extracellular lysosomes (= matrix vesicles).

Cholesteatoma↗
PubMed1981

[The effect of irradiation on the inner laryngeal lymphatics (author's transl)].

In a combined lymphangioscopical and ultrastructural examination 7 months post telecobalt 60 irradiation with 60 Gy, the morphological and functional aspects of the inner laryngeal lymph capillaries were studied. The prominent feature of the morphological changes was the endothelial damage of the lymphatic capillaries including swelling, vacuolisation and necrosis. Many lymph vessels were dilated but patent. A few capillaries where collapsed and surrounded by increased amounts of fibrous tissue, some capillaries where lacking their endothelial lining. So degeneration of the endothelial cell i.e. of the endothelial junctions and focal increase of interstitial collagen with resulting stenosis of the capillaries may be observed. The clinical and functional aspects of the morphological findings are discussed.

Carcinoma, Squamous Cell↗
PubMed1981

[Obliteration of the mastoid air cell system with porous tricalcium phosphate ceramic. An animal experiment of the bulla tympanica of the pig (author's transl)].

The paper reports on an animal experiment on the obliteration of mastoid cavities with tricalcium phosphate ceramic. The pneumatic air cell system of the bulla tympanica of pigs of 11-12 weeks of age was totally removed in one group of animals and partially removed in the second group. In this second group, apical part of the bulla was left intact. The operation cavity was then obliterated with adjacent layers of porous tricalcium phosphate ceramic. Histological sections wee evaluated for both groups of animals after survival time of 1, 3 and 6 months. Initially, an ingrowth of granulated tissue between the ceramic layers and into the porous surface can be observed. This dissolves the ceramic material, which is substituted by bony tissue. Pneumatic cells in the apical part of the bulla, which were left intact in the second group of animals, do not obliterate after the air supply has been cut off by sealing the basal part. Cystic cavities remain which contain a serous exudate. After 6 months, the mucous membrane of such cells shows signs of "sclerosis". Formation of spongy bony tissue with marrow spaces can be seen in most of the apical areas of the growing bulla. There is no formation of air-containing cells. It appears from our preliminary results obtained from animal experiments that porous tricalcium phosphate ceramic may be a suitable material for the obliteration of mastoid cavities.

Animals↗