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Biomedical subjects

G Richter

Publications and source records attributed to G Richter.

At least 181 records · Page 10Linked to original sources
PubMed1989

[The sprue behavior of nonprecious metals].

As a base for single crowns and bridge anchors the individual casted construction combined with the manufactured root post offers undisputed advantages. At casting silver-palladium alloys, the root posts possibly may change the characteristic properties of their material. The casting reactions of sipal with cylindrical pins made of pure titanium (EMO Ti110) and root posts with adhesion head made of implant steel (URX2CrNiMoN18.12(0] was investigated. Interstice-free castings of sipal to pin from implant steel and titanium can be demonstrated by means of pictures of metallographic (grinding) specimens investigated by light- and electron-beam microscopy. The casting quality is identified mainly by selection of the embedding mass, the rise of the preheating temperature and period of preheating.

Crowns↗
PubMed1989

[Optimization of surgical tooth preservation using a fully ready-made post implant construction system for endodontic implantation].

By individual cast constructions necessary for endodontic implantations the cold-formed post material (pure titanium/implant steel) has to be heat-treated by recasting (Sipal as construction material). Therewith are connected structure changes with distinct worsening of the material properties. By means of the potentiodynamic anodic polarization it can be proved that the silver-palladium alloy is the component with the highest susceptibility to corrosion. A suitable alternative to the individual cast construction is a fully ready-made implant construction system made from pure titanium which can solve the problems of bond, corrosion and strength.

Crowns↗
PubMed1989

[Bonding strength of adhesive resins with non-precious metal alloys in relation to conditioning methods].

The tensile strength of adhesive metal bonds of the alloys Gisadent KCM degrees, KCM 83 degrees and NCA degrees with the adhesive materials Evicrol degrees, Spofacryl degrees and ABC-Cement degrees has been determined in dependence on the conditioning methods sandblasting, electrolytic etching and Silicoater degrees treatment. The Silicoater degrees treatment was found to be the most successful conditioning method independent on the alloy and the used adhesives. After electrolytic etching increased bond strength values are to be expected particularly with Gisadent NCA degrees. Independent on the used alloy and the conditioning method Spofacryl degrees shows the best adhesive properties of the tested adhesive materials.

Dental Alloys↗
PubMed1989

[Percutaneous puncture and drainage of pancreatic pseudocysts].

A total of 63 patients with cystic pancreatic lesions (60 pseudocysts, 3 true cysts) underwent percutaneous therapeutic procedures with ultrasound guidance. Repeated needle aspirations were performed in 50 patients, 13 underwent transabdominal catheter drainage. Complete resolution of the cystic lesion was obtained in 37 (59%) patients overall, while 41% required further therapy. Thirty seven (62%) of the 60 pancreatic pseudocysts were successfully drained by percutaneous procedures, in 23 (38%) fluid collections recurred. Complications of the drainage procedures occurred in two patients (3.2%). Considering these results, ultrasound guided needle aspiration and catheter drainage of pancreatic pseudocysts have proved to be of value for both nonsurgical temporary and definitive treatment.

Adolescent↗
PubMed1989

Near-drowning.

Explore the source record for details and available documents.

Drowning↗
PubMed1989

[Myocardial infarct with normal coronary angiogram].

We report on a 50-year-old woman who was able to escape from the cellar which contained fermenting wine, whereas her husband died there. Immediately after the incident she developed an extended myocardial infarction of the anterior and septal wall in spite of an intravenous administration of streptokinase within 2 h. Four weeks later coronary angiography showed normal vessels. A spasm is assumed, favored by systemic hypoxia, CO2-overloading, and systemic adrenergic reaction. The postulated cause of the special localization of the spasm is an unknown individual local factor as in all other similar cases.

Coronary Angiography↗
PubMed1988

Influence of experimental hyperthyroidism on blood and myocardial serotonin in rats.

Recent reports suggest a role for serotonin in the pathogenesis of primary hypertension and left ventricular (LV) hypertrophy. In this study, we have induced LV hypertrophy by oral feeding of thyroxine at increasing dosages (150-450 micrograms/kg b.wt.) over a 5-week period. The effects of hyperthyroidism on cardiovascular parameters, blood and myocardial serotonin concentrations were assessed. Water-fed rats and formerly hyperthyroid recovered animals served as controls. Thyroxine caused a significant LV hypertrophy: hyperthyroid rats 2.19 +/- 0.16*; controls 1.65 +/- 0.13 g/kg b.wt. (mean +/- SD; *P less than 0.05). An almost complete regression of LV hypertrophy occurred in the recovery group (1.66 +/- 0.20 g/kg b.wt.) 3 weeks after cessation of thyroid hormone application. Thyroxine-treated animals showed a significant increase of serotonin blood levels (thyroxine rats: 2108 +/- 781*, recovery: 1132 +/- 726, controls: 705 +/- 480 ng/ml; *P less than 0.05). The concentrations of serotonin in left ventricular myocardium were increased after thyroid hormone application, whereas the highest levels were found in the recovery group (thyroxine rats: 139.1 +/- 30.4, recovery: 167.2 +/- 43.1, controls: 68.9 +/- 27.9 mg/ml homogenate). Serotonin-containing cells in the left ventricular myocardium were stained immunohistochemically. They were localized perivascularly and were assumed to represent tissue mast cells. In experimental hyperthyroidism the serotonin levels in blood and heart are increased possibly indicating an interaction of both hormones in thyroxine-induced cardiomyopathy.

Administration, Oral↗
PubMed1988

Effect of dietary choline on volatile fatty acids in rumen liquid of sheep and rumen dry matter degradability of untreated and ammonia-treated wheat straw.

Three rumen fistulated wethers consumed a roughage (1200 g artificially dried grass) or a concentrate/roughage diet (600 g concentrate, 400 g dried grass per animal and day). The diets were unsupplemented or 0.5, 1 or 2 g choline per animal and day were added. After a 14-day feeding period, samples of rumen liquid were taken 0, 1, 2, 3, 4 and 6 h after morning feeding. In a second experiment, untreated and ammonia-treated wheat straw were incubated in nylon bags for 6, 12, 24, 48 and 72 h in rumen of 5 sheep fed on 1.2 kg dried grass and without or with 1 g choline per day. Choline supplementation decreased the total concentration of volatile fatty acids in rumen liquid in both types of diet (roughage: 106, 83, 89 and 87; concentrate/roughage: 142, 114, 91 and 106 mmol/l for 0, 0.5, 1 and 2 g choline per day resp.). Concentration of acetate and branched chain fatty acids in both diets and butyrate in concentrate/roughage diet was reduced as total acids. Butyrate in roughage diet was increased by added choline. Molar propionate concentration was not significantly influenced by choline (P greater than 0.05). Choline resulted in a little increase (P greater than 0.05) of dry matter degradability in rumen, especially when NH3-treated straw was incubated. The effect of choline on milk fat production of cows fed with diets rich in concentrate is probably not related to changes in rumen fermentation and digestion.

Acetates↗
PubMed1988

[The entero-insular axis: the new incretin candidate glucagon-like peptide-1(7-36)amide (GLP-1(7-36))amide].

The functional connection between the gut and pancreatic islets is described by the term "enteroinsular axis". A humoral factor of the gut that might enhance the glucose-induced secretion of insulin is named "incretin". For many years glucose-dependent insulin-releasing polypeptide (GIP) was the strongest incretin candidate. However, recent evidence suggests that glucagon-like peptide-1(7-36)amide represents a more potent physiological incretin. The sequence of GLP-1 is identical in various mammals including man. The 7-36 sequence of the original peptide is a potent insulin-releasing peptide in vitro and in vivo. GLP-1(7-36)amide was found in the human bowel; its circulating level rises in answer to oral glucose and after meals. Recently, specific high-affinity binding sites for GLP-1(7-36)amide were demonstrated on rat insulinoma-derived RINm5F cells. In this model system for B-cell studies the peptide has potent stimulatory effects on cAMP formation, insulin-mRNA transcript synthesis, and insulin release. Further studies in the insulinotropic action of GLP-1(7-36) amide in health and disease will be of great importance.

Animals↗
PubMed1987

[Bone and soft tissue tumors--progress in this decade].

Conventional plain film roentgenography is the basic examination of bone tumors. Modern digital roentgenography offers technical innovations but no fundamental new diagnostic dimensions. Computerized and magnetic resonance-tomography allow a far better delineation of the tumor spread (staging). These new imaging methods together with ultrasound have revolutionized the diagnosis of soft tissue neoplasms, not visible on plain film roentgenograms except lipomas and calcifications.

Bone Neoplasms↗
PubMed1987

[Vitamin E requirement of chicks and young hens].

In 4 experiments young chickens of the species White Leghorn received semisynthetic rations with a vitamin E content less than 1 mg/kg basal ration. Sunflower oil heated with FeCl3 supplement was used as a factor increasing requirement. Feed intake, live weight gain and feed expenditure with semisynthetic rations without oil supplements did not depend on vitamin E supplements. After the feeding of rations without vitamin E animal losses were higher. The losses were normalized by 1 mg vitamin E supplement per kg feed. Rations containing sunflower oil without vitamin E supplementation resulted in encephalomalacia of the young chickens. Vitamin deficiency increased triiodine thyronine content in the blood plasma. Antibody formation after the application of human gamma globulin did not depend on the vitamin E supply studied. A vitamin E requirement of young chickens and young hens of the laying species of less than 1 mg/kg mixed feed is derived from the results.

Animal Feed↗
PubMed1987

[Testing of the digestibility of crude nutrients and of the applicability of tapioca for laying hens and young chickens].

By means of the difference method an apparent digestibility of 88.3% of the organic matter, 50.4% of the crude protein, 25.1% of the crude fat, 12.7% of the crude fibre and 94.2% of the N-free extractives of Thai tapioca meal was ascertained in colostomized laying hens. It is possible to use 20% tapioca meal in the feed for chickens and pullets without a decrease in performance. Two experiments with laying hens were carried out with 5-30% tapioca. Egg production decreases slightly with a tapioca quota of 10% and more. This is why a feeding limit of 5% is recommended. With 20% tapioca the decrease of performance was 1.5%. Tapioca meal diminishes the intensity of the yellow of the yolks. Cereals may be partially substituted by tapioca in the feed for chickens, pullets and laying hens.

Animal Feed↗