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Biomedical subjects

W Braun

Publications and source records attributed to W Braun.

At least 199 records · Page 11Linked to original sources
PubMed1985

[Value of cervical myelography in lateral cervical root compression].

The roentgenograms of preoperative cervical metrizamide myelography performed in 133 patients who had undergone surgery for a lateral cervical root compression (foraminotomy) were retrospectively re-evaluated without knowledge of the findings at surgery. Detailed criteria of the radiologic root cavity recess were compared with details of findings at surgery, in order to check the value of the information provided by the myelogram with regard to the morphological nature of the root compression. A review of the two main categories--"soft prolapse with or without primary sequestrum" and "hard protrusion" revealed different myelographic findings. It was not possible to establish an unequivocal diagnosis in individual cases and with regard to forms of root compression exhibiting a greater degree of differentiation.

Evaluation Studies as Topic↗
PubMed1984

Polypeptide secondary structure determination by nuclear magnetic resonance observation of short proton-proton distances.

The use of proton-proton nuclear Overhauser enhancement (NOE) distance information for identification of polypeptide secondary structures in non-crystalline proteins was investigated by stereochemical studies of standard secondary structures and by statistical analyses of the secondary structures in the crystal conformations of a group of globular proteins. Both regular helix and beta-sheet secondary structures were found to contain a dense network of short 1H-1H distances. The results obtained imply that the combined information on all these distances obtained from visual inspection of the two-dimensional NOE (NOESY) spectra is sufficient for determination of the helical and beta-sheet secondary structures in small globular proteins. Furthermore, cis peptide bonds can be identified from unique, short sequential proton-proton distances. Limitations of this empirical approach are that the exact start or end of a helix may be difficult to define when the adjoining residues form a tight turn, and that unambiguous identification of tight turns can usually be obtained only in the hairpins of antiparallel beta-structures. The short distances between protons in pentapeptide segments of the different secondary structures have been tabulated to provide a generally applicable guide for the analysis of NOESY spectra of proteins.

Aprotinin↗
PubMed1984

Evidence for heterogeneity in hereditary hemochromatosis. Evaluation of 174 persons in nine families.

Hereditary hemochromatosis is an autosomal recessive disease in which the gene is linked to the HLA system. Investigation of nine unrelated probands and their family members has revealed distinct groups based on biochemical and clinical manifestations of the disease. Four different types of disease expression were identified: Group I--classic hereditary hemochromatosis with elevated transferrin saturation, serum ferritin levels, and liver iron content; Group II--severe iron overload, accelerated disease manifesting at an early age; Group III--elevated total body iron stores, normal transferrin saturation and serum ferritin levels; Group IV--markedly elevated findings on serum biochemical tests, e.g., transferrin saturation, serum ferritin levels, with minimal elevation in total body iron stores. This evidence for several clearly distinguishable modes of expression in different families suggests that more than one genetic lesion in iron metabolism may be responsible for iron overload in hereditary hemochromatosis. This genetic heterogeneity may be helpful in delineating the fundamental abnormalities in iron metabolism in this group of disorders.

Absorption↗
PubMed1984

Renal transplantation of patients on chronic peritoneal dialysis.

A retrospective review of patients transplanted from peritoneal dialysis was performed to assess the risk of this form of dialysis for patients awaiting renal transplantation. Eighteen transplants have been performed in 16 patients, ages 6 to 57 years, undergoing chronic peritoneal dialysis over the past 4 years. Sixteen were from cadaver donors, and two were from living related donors (LRD). The patients had been undergoing intermittent peritoneal dialysis or continuous ambulatory peritoneal dialysis (CAPD) using permanent silastic catheters, from five days to 4 years. No patient had clinical evidence for peritonitis at the time of transplantation. The peritoneal catheter was removed at the time of transplant in all cadaver donor recipients without complication. One recipient of a LRD kidney had the catheter removed two days prior to transplant. Cultures of the catheter were sterile in 16 cases. Two patients had positive peritoneal catheter cultures at the time of transplant but were treated with appropriate antibiotics and never developed clinical peritonitis. Fourteen transplants had postoperative fevers. No definite source was found in 13; one had fever in relation to acute graft rejection. The fevers resolved in all patients either spontaneously or subsequent to therapy. Other complications were similar to those seen in patients transplanted from hemodialysis. Hemodialysis was performed as needed pretransplant and posttransplant using a temporary femoral vein catheter or arteriovenous fistula without complication. Nine patients are alive with a functioning kidney 1 to 36 months posttransplant (mean 17 months). Six transplants rejected (five patients), and one failed secondary to renal vein thrombosis. Two patients died posttransplant, one after a cerebrovascular accident, and one due to an unknown cause 1 month postnephrectomy for rejection. In conclusion, patients undergoing chronic peritoneal dialysis can be successfully transplanted without a significant incidence of complications related to their peritoneal dialysis.

Adolescent↗
PubMed1984

[Value of bone scintigraphy in secondary (intestinal) hyperparathyroidism].

We report on 4 patients with secondary hyperparathyroidism of intestinal origin presenting a characteristical pattern of distribution, namely focal accumulations of 99mTc-methylene diphosphonate on locations typical of Looser's zones. In accordance with other authors we demonstrate the higher sensitivity of skeletal scintigraphy as compared to radiography which is well known from other disorders of bone. We also refer to the problems of differential diagnosis arising when multiple foci are visible on bone scan.

Aged↗
PubMed1984

Results of spinal cord stimulation in patients suffering from chronic pain after a two year observation period.

Attempts were made to treat 50 patients suffering from various types of chronic pain with SCS (PISCES). In 33 patients the test stimulation was successful so that an implantation of the system was carried out. After a minimum observation period of two years, only six patients still reported satisfactory alleviation of pain. A more careful selection of patients suffering from different types of pain would appear to be the pre-requisite for better results.

Aged↗
PubMed1984

[Divorces, 1982].

Explore the source record for details and available documents.

Cohort Studies↗
PubMed1984

[Glomerular filtration in low birthweight neonates].

The glomerular filtration rate (GFR) was estimated in mature newborns appropriate for gestational age (AGA), mature newborns small for gestational age (SGA) and premature newborns AGA on the 2nd day and the end of the 3rd week of life. The GFR was determined by mannitol using the slope-clearance technique. On the 2nd day the GFR is significantly diminished in mature newborns SGA (1.21 ml/kg X min) compared to mature newborns AGA (1.84 ml/kg X min) as well as premature newborns AGA (1.54 ml/kg X min). During the first 3 weeks of life the GFR increases significantly in mature newborns both AGA (2.20 ml/kg X min) and SGA (1.65 ml per kg X min), whereas the increase is insignificant in premature newborns AGA (1.70 ml per kg X min). Therefore there is no difference between mature newborns SGA and premature newborns AGA at the end of the 3rd week of life. The decreased GFR of newborns SGA during the first weeks of life has to take into consideration for dosage of drugs tending to cumulate and for composition of parenteral nutrition.

Glomerular Filtration Rate↗
PubMed1984

[Chronic subdural hematoma--operative treatment in 77 patients with burr trepanation].

It is reported of 77 patients with chronic subdural haematoma all treated by burr-hole trepanation. The results are demonstrated and compared to those of other kinds of treatment. In our opinion burr-hole trepanation is the superior treatment of chronic subdural haematoma, because only by surgical treatment there is a rapid ans definitive relief of brain pressure. In comparison with osteoplastic craniotomy burr-hole trepanation is less invasive and more considerate for the patients.

Chronic Disease↗
PubMed1983

Conformation of glucagon in a lipid-water interphase by 1H nuclear magnetic resonance.

A determination of the spatial structure of the polypeptide hormone glucagon bound to perdeuterated dodecylphosphocholine micelles is described. A map of distance constraints between individually assigned hydrogen atoms of the polypeptide chain was obtained from two-dimensional nuclear Overhauser enhancement spectroscopy. These data were used as the input for a distance geometry algorithm for computing conformations that would be compatible with the experiments. In the region from residues 5 to 29 the mobility of the polypeptide backbone and most of the amino acid side-chains was found to be essentially restricted to the overall rotational tumbling of the micelles. The secondary structure in this region includes three turns of irregular alpha-helix in the segment of residues 17 to 29 near the C terminus, a stretch of extended polypeptide chain from residues 14 to 17, an alpha-helix-like turn formed by the residues 10 to 14 and another extended region from residues 5 to 10. In the N-terminal tetrapeptide H-His-Ser-Gln-Gly- the two terminal residues are highly mobile, indicating that they extend into the aqueous phase, and the mobility of the residues Gln3 and Gly4 appears to be only partially restricted by the binding to the micelle. The absence of long range nuclear Overhauser effects between the peptide segments 5-9 and 11-29, and between 5-16 and 19-29 shows that the polypeptide chain does not fold back on itself and hence that micelle-bound glucagon does not adopt a globular tertiary structure. Previously it was shown that the polypeptide backbone of glucagon is located close to and runs roughly parallel to the micelle surface. Combination of these observations suggests that the overall spatial arrangement of the glucagon polypeptide chain in a lipid-water interphase is largely determined by the topology of the lipid support, in the present case the curvature of the dodecylphosphocholine micelles. The tertiary structure is further characterized by the formation of two hydrophobic patches by the side-chains of Phe6, Tyr10 and Leu14, and the side-chains of Ala19, Phe22, Val23, Trp25 and Leu26, respectively.

Amino Acid Sequence↗
PubMed1983

Pseudo-structures for the 20 common amino acids for use in studies of protein conformations by measurements of intramolecular proton-proton distance constraints with nuclear magnetic resonance.

"Pseudo-structures" of the 20 common amino acid residues are introduced for use in protein spatial structure determinations, which rely on the use of intramolecular proton-proton distance constraints determined by nuclear Overhauser effects as input for distance geometry calculations. The proposed structures satisfy requirements for the initial structural interpretation of the nuclear magnetic resonance data that arise from the absence of stereospecific assignments and/or limited spectral resolution for certain resonance lines. The pseudo-atoms used as reference points for the experimental distance constraints can be used in conjunction with the real amino acid structures representing the van der Waals' constraints on the spatial molecular structure, or with simplified models in order to reduce the computing time for the distance geometry calculations.

Amino Acids↗