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Biomedical subjects

R Huber

Publications and source records attributed to R Huber.

At least 631 records · Page 35Linked to original sources
PubMed1979

Crystal structure analysis of the tetragonal crystal form are preliminary molecular model of pig-heart citrate synthase.

The crystal structure of pig heart citrate synthase was analyzed at 0.35-nm resolution. Chain tracing was possible and an initial molecular model constructed. The dimensions of the dimer molecule (located on a crystallographic diad) are 7.5 x 6.0 x 9.0 nm. The chain folding is characterized by the predominance of helices and the absence of sheet structure. The electron density accounts for 355 residues per monomer, so that about 80 residues must be disordered in the crystal. The disordered segment in probably N-terminal. The ordered part consists of two closely associated domains, a large domain with 300 residues and a C-terminal domain of 55 residues consisting of 3(anti)parallel helices. The large domain is built from 12 helical segments, some of which are buried in the interior of the molecule. Inhibitor binding studies with citrate and CoA revealed citrate binding sites but showed no electron density for CoA. It is suggested that CoA binds to the disordered, flexible N-terminal domain. Experiments of limited proteolysis with trypsin showed that under conditions a segment of Mr 9000 is cleaved off selectively. The remaining 35 000-Mr part is dimeric.

Animals↗
PubMed1979

Isolation of the globular region of the subcomponent q of the C1 component of complement.

Digestion after heat treatment of the subcomponent q of the C1 component of complement by collagenase leads to the isolation of the globular region of the protein. This product ('heads') is composed of three chains giving an overall molecular weight of about 57000. About half of the collagen-like region present in C1 q is lost after digestion. The 'heads' are shown to be soluble and hemolytically active products.

Amino Acids↗
PubMed1979

[The influence of uric acid on the calcium oxalate stone formation (author's transl)].

Statistic analysis of data from 209 calcium oxalate stone patients and 42 stone-free patients pertinent to the concentration and excretion of uric acid in urine and of uric acid levels in the serum yielded no significant difference between the two groups. Only 17% of the calcium oxalate stone patients suffered from hyperuricuria and hyperuricemia was found only in 15% of these patients. Based on these findings, our in-vitro experiments as to the influence of uric acid on calcium oxalate stone formation yielded the following results: firstly, precipitates in urine form only at uric acid concentrations which in-vivo are rate exceptions humans, and secondly, the precipitates at pH 5.5--6.0 always contain uric acid, and a precipitation of calcium oxalate only is never observed. From the experiments one has to conclude that there exists no "salting-out effect" of uric acid on calcium oxalate in urine but rather that precipitate formation reflects the individual solution- and crystallization characteristics of the precipitating compounds.

Calcium Oxalate↗
PubMed1979

[The conservative therapy of urolithiasis (author's transl)].

Some common conservative treating methods of urolithiasis are critically discussed. Based on physico-chemical relationships of solubility and cristallisation of stone-forming compounds our own methods of conservative treatment of urolithiasis is presented.

Allopurinol↗
PubMed1979

[Accuracy of lymphography in carcinoma of the cervix (author's transl)].

A review has been made of lymphographic diagnoses recorded from patients with cervical carcinoma over more than five years. The diagnosis by lymphography of nodes metastases had to be altered in some 25 per cent, and correction proved necessary also in cases in which lymphography had failed to yield conclusive information. - In the group with lymphographically secured cancer lymph nodes coincided with histological results in 70 per cent of all primary and 90 per cent of secondary checks. Comparable gaps were recorded also from the group with lymphographically inconclusive information on lymph node cancer. - The following conclusions are drawn from the study described: (a) The accuracy of lymphographic diagnosis depends on the experiences of the examiner and changes within time and this must be considered in the evaluation of therapeutic success or failure. - (b) Conclusive findings in the context of lymph node problems are obtainable from selective use of lymphography.

Carcinoma, Squamous Cell↗
PubMed1978

Quantitative element investigations in urine, serum, kidney and muscle tissue of calcium oxalate stone patients.

Concentration and excretion in 24-hour urine, as well as serum concentrations of Na, K, Mg, Ca, Cl, P, uric acid and citrate were investigated in 209 calcium oxalate stone patients and 42 stone-free patients. Especially the concentration values of the urine components, except for uric acid and citrate, were found to be significantly lower for calcium oxalate stone patients. 21% of the stone patients showed hypercalciuria; hypercalciuria combined with hyperuricuria was found in only 7.1% of the cases and a solitary hyperuricuria in only 17%. As for kidney cortex, kidney papilla and muscle tissue in 10 calcium oxalate stone patients and 10 stone-free patients, the concentrations of Na, K, Ca, Mg as well as some trace elements were determined quantitatively by means of neutron activation analysis. Statistic analysis yielded a significantly lower sodium content of the kidney cortex within the stone-carrying group. Mean values of the calcium concentration in stone patients were lower for papilla and muscle tissue than in the control group. For magnesium no clear differences were found. The iron content in the papilla and muslce tissue of stone patients was significantly lower.

Calcium↗
PubMed1978

Crystallization, crystal structure analysis and atomic model of the complex formed by a human Fc fragment and fragment B of protein A from Staphylococcus aureus.

Crystals of the complex formed by human Fc fragment and fragment B (FB) of protein A from Staphylococcus aureus were prepared and the crystal structure determined at high resolution by multiple isomorphous replacement. Phase were improved considerably by combining these phases with calculated phases from the Fc component. FB is a small globular protein built of three parallel helices arranged in a triangular array. It binds by the first two helices of Fc and is attached to segments of CH2 and CH3. The CH3 module is unchanged between complex and Fc fragment crystals, but CH2 changes its position slightly relative to CH3. In addition, the upper third of CH2 is disordered in the complex crystals. Possible sources of this disorder are discussed.

Antigen-Antibody Complex↗
PubMed1977

Gastric and duodenal ulcer healing under placebo treatment.

The healing time relation of 30 gastric and 15 duodenal ulcers was assessed by repeated endoscopic measurements of ulcer size on days 1, 21, and 42 of a 6-week period, during which a selected population of patients was being treated as outpatients on an inert placebo. Antacids in small amounts were only given in case of ulcer pain. There was evidence for a linear relationship between the absolute initial ulcer size and its reduction with the time in incompletely healed ulcers of both types. Their percentage reduction from the original size was 71% after 3 weeks in gastric and 83% in duodenal ulcers; 82% after 6 weeks in gastric and 83% in duodenal ulcers. The healing time course for both types of ulcers appeared to follow an exponential function. The calculated half-life was 1.7 weeks for gastric and 1.9 weeks for duodenal ulcers. The number of healed duodenal ulcers observed at the 3-week examination was significantly greater than that of healed gastric ulcers (P = 0.05). It is concluded that repeated measurements of the ulcer size before complete ulcer healing contribute to a optimal characterization of the healing time course. The calculated half-life of less than 2 weeks makes shorter control intervals reasonable for both types of ulcers. The ulcer half-life appears to be a more accurate criterion of the healing process than that of complete healing.

Adolescent↗
PubMed1976

Crystallographic structure studies of an IgG molecule and an Fc fragment.

The crystal structures of a human IgG antibody molecule Kol and a human Fc fragment have been determined at 4-A and 3.4-A resolution respectively, by isomorphous replacement. The electron-density maps were interpreted in terms of immunoglobulin domains based on the Rei and McPC 603 models (Kol) and by model-building (Fc). The Fab parts of Kol have a different quaternary structure from that observed in isolated crystalline Fab fragments, there being no longitudinal V-C contact in Kol. The Fc part C terminal to the hinge is disordered in the Kol crystals. It is suggested that the Kol molecule is flexible in solution, whereas fragments are rigid. In the Fc fragment both CH3 and CH2 show the immunoglobulin fold. The CH3 dimer aggregates as CH1-CL while CH2 are widely separated from each other. The carbohydrate bound to Fc is in fixed position. From these structures a hypothetical liganded antibody molecule has been constructed, which is assumed to be rigid.

Antigen-Antibody Reactions↗