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Biomedical subjects

C Braun

Publications and source records attributed to C Braun.

At least 145 records · Page 8Linked to original sources
PubMed1990

Nitrous oxide reductase from denitrifying Pseudomonas stutzeri. Genes for copper-processing and properties of the deduced products, including a new member of the family of ATP/GTP-binding proteins.

Nitrous oxide (N2O) respiration by the denitrifying bacterium Pseudomonas stutzeri requires the synthesis of the multi-copper enzyme N2O reductase, nosZ, the structural gene for this enzyme, is part of a DNA region of approximately 8 kbp that carries several essential genes. Insertional mutagenesis of the region downstream of nosZ generates apoenzyme-synthesizing strains, which argues for the existence of functions for copper acquisition or copper processing, or both, for N2O reductase. The relevant DNA region of approximately 3.2 kbp was sequenced and found to consist of three genes, nosDFY, presumably within a single transcriptional unit. Cellular concentration, copper content, and location of the N2O reductase protein were studied with mutants which were affected in the three genes. Interactions of the deduced gene products among each other and with the cytoplasmic membrane appear to be analogous to those of the components of osmotic-shock-sensitive bacterial transport systems. The 33.8-kDa product of the nosF gene belongs to the family of nucleotide-binding proteins [C. Higgins et al. (1986) Nature 323, 448-450]. Its amino acid sequence shows two canonical nucleotide-binding motifs, and the positional identity of amino acids to members of this family is around 30%. The 29.4-kDa product of the nosY gene is a hydrophobic protein with six predicted transmembrane helices and an export signal. The 48.2-kDa product of the nosD gene is a periplasmic component; it carries an export signal and is a hydrophilic protein. N2O reductase itself is a periplasmic enzyme. Our results provide evidence for an auxiliary system of Cu processing and suggest its involvement in the periplasmic biosynthesis of the Cu centers of N2O reductase.

Amino Acid Sequence↗
PubMed1990

[Effect of long-term therapy with prazosin/propranolol on blood pressure and cardiopulmonary function in essential hypertension].

In 25 hypertensives (42 +/- years), predominantly at stage I according to WHO-criteria, by the application of daily 5 +/- 4 mg prazosine and as combination of 9 +/- 6 mg with 73 +/- 31 mg propranolol the blood pressure normalized itself from on an average 183 to 148 mgHg systolically and 113 to 93 mgHg diastolically. In a long-term experiment confirmable also echocardiographically prazosine alone decreased the afterload of the heart in an unchanged high energy requirement at rest, and in a submaximal ergostasis the aerobic metabolic situation deteriorated. This could again be balanced by the combination with propranolol, whereby oxygen pulse, product of the pressure frequency and PWC 130 even improved. Function and size of the left ventricle remained echocardiographically uninfluenced in the two forms of therapy.

Adult↗
PubMed1990

Significant association between outdoor NO2 and respiratory symptoms in preschool children.

A study of 1225 preschool children was conducted in four regions of Switzerland with different levels of air pollution to investigate the relationship between air pollution and respiratory symptoms. Daily symptoms were recorded by parents on a diary form and air pollution exposure assessed by personal NO2 samplers. Each family participated for 6 weeks and personal samplers were changed every week. The frequency of respiratory symptoms per child and day was found to increase with increasing levels of NO2 measured outdoors. This relationship remained significant in a multiple regression model in which the factors smoking, origin, indoor air pollution, age and sex, season, and parents appreciation of air pollution at the living site were taken into account.

Air Pollutants↗
PubMed1990

[Correlation of respiratory tract symptoms in young children and NO2 concentrations of the outside air].

In four regions of Switzerland (2 towns, 1 municipal agglomerate, 1 rural area) the relationship between the degree of air pollution measured in terms of NO2 and the incidence of airway symptomatology was investigated in 1,225 young children. The airway symptoms were recorded by the parents in a diary; the NO2 loading was measured with the aid of personal collecting tubes at the place of residence of the child. A significant relationship was found to exist between the mean incidence of airway symptomatology per child and day, and the individually measured NO2 concentration in the outside air at the child's place of residence. This relationship remained significant even when, in a multiple regression analysis, account was also taken of other major factors, such as smoking, nationality, individual susceptibility to airway diseases, the season of the year, and the subjective assessment of the air pollution at the place of residence, were also taken into account.

Air Pollutants↗
PubMed1989

[A treatment concept using external transfixation in unstable defect trauma of the knee joint].

The main problems in the treatment of severe knee injuries with extensive soft tissue damage, ligamentary lesions and compound fractures consist in the high risk of infection and complex instability of the joint. 20 patients suffering such type of trauma were treated by a schedule comprising an extensive debridement and a combination of minimal internal osteosynthesis and external transfixation. Secondary operations were always performed as a second look in all patients and various surgical reconstructions of the soft tissue coverage under continuous protection of the external fixation. Most patients obtained satisfactory functional results, only 2 cases ended up with arthrodesis due to deep infection.

Adult↗
PubMed1988

[The Graner capitate interposition arthroplasty in lunate malacia].

In capitate interpositional arthroplasty (Graner II) the necrotic lunate bone is removed and the congruity of the proximal carpal row is restored by interposition of the proximal half of the capitate. The carpal bones are fused except for the scaphotrapezial joint. In this fashion carpal instability can be safely treated. Good results are achieved for both grip strength and relief of pain. Motion is restricted but with a useful range of motion remaining. The arc of remaining motion can be shifted into extension through the use of an opening wedge osteotomy of the capitate. Capitate interpositional arthroplasty without an intercarpal arthrodesis has poor result because of remaining carpal instability.

Adult↗
PubMed1988

Screening urine before microscopy, by automated test-strip preselection: clinical evaluation of the improved Rapimat II/T (Behring).

In many laboratories, microscopy of urines is restricted to specimens selected on the basis of positive tests, mainly for protein, blood, nitrite, and leukocyte esterase. Here, we analyzed several hundred specimens by use of multiple dipsticks, read in an improved reflectometer. By comparing the results with quantitative microscopy, it could be shown that this system allows selection, with acceptable sensitivity and specificity, of those specimens that are likely to contain clinically important microscopic elements.

Autoanalysis↗
PubMed1987

Gene cluster for streptomycin biosynthesis in Streptomyces griseus: analysis of a central region including the major resistance gene.

A central segment of a cluster of biosynthetic genes for the antibiotic streptomycin cloned from Streptomyces griseus was analysed for open reading frames, as well as for transcriptional and translational activity. The nucleotide sequence revealed two significant open reading frames, ORF1 and APH(6), orientated in opposite directions and with a spacer of 885 bp between the start codons. The first, ORF1, had a coding capacity of 38 kDa. One open reading frame, APH(6), was identified as the major resistance gene coding for streptomycin 6-phosphotransferase, a protein of 307 amino acid residues and 33 kDa. Sequence determination of the first 14 N-terminal amino acid residues of the purified APH(6) enzyme protein was in agreement with the proposed primary structure. The possible identity of the presumed gene product of ORF1 with an in vitro translated protein (apparent molecular weight 41 kDa) is discussed. Comparison of the two APH(6) genes from S. griseus and the hydroxystreptomycin-producing S. glaucescens (cf. Vögtli and Hütter 1987) revealed 75% nucleotide sequence homology in the coding region and 74% conservation of the polypeptide sequence. Two protein domains which are highly conserved in other antibiotic and protein phosphotransferases were detected.

Amino Acid Sequence↗
PubMed1986

[Macro- and microreplantations of the lower leg and foot].

Amputations suitable for replantation in the distal lower leg and foot are seldom. There is no indication if shortening will exceed 5 cm or loss of sensitivity is to be expected. Forefood and toe replantations are to be seen predominantly under aesthetic points of view. Satisfactory results in 10 own cases could be achieved if indications for lower leg replantations were limited to guillotine-type amputations, children and some bilateral lesions. Polytrauma as a rule is not a good indication.

Amputation, Traumatic↗
PubMed1986

Filamentous actin in paramecium cells: functional and structural changes correlated with phalloidin affinity labeling in vivo.

Rhodaminylated (R)-phalloidin microinjected into Paramecium tetraurelia cells at a final concentration of greater than or equal to 20 micrograms/ml produces considerable functional and structural changes. F-actin bundles (with 20 micrograms/ml phalloidin within 15 min) are formed, which subsequently (greater than 30 min) are sequestered into autophagic vacuoles; simultaneously, the originally intense fluorescence of a narrow cortical layer becomes more and more diminished. When such microinjected cells are processed for electron microscopy, they display concomitant ultrastructural alterations, namely, the formation of transcellular bundles of 5-7 nm-thick filaments, which subsequently appear in autophagosomes, as well as a considerable reduction of filamentous materials in the cortex. This, in turn, entails a considerable restructuring of the cortex, enabling free access of various structural components to the cortex. Higher doses of R-phalloidin abolish cytoplasmic streaming (e.g., 50 micrograms/ml after 20-30 min); although the cells may survive, new secretory organelles (trichocysts) are no longer docked to the cell membrane. In contrast, exocytosis of docked trichocysts (as well as subsequent membrane resealing and retrieval) is not impaired under any conditions. Cortical F-actin may account for the cytoplasmic streaming that may normally guarantee the delivery of new trichocysts to free docking sites at the cell membrane. When docking is inhibited by high R-phalloidin doses, excess free trichocysts are sequestered into autophagosomes (crinophagy). One of the most sensitive cell functions is food vacuole formation (assayed by prelabeling with India ink), which correlates with the presence of R-phalloidin labeling in the cytostomal region and around food vacuoles. The main conclusions from this work are that filamentous actin may be involved in structuring of the cortex and in cytoplasmic streaming, and may therefore influence the formation, and possibly the transcellular transport (cyclosis), of food vacuoles, as well as the docking of trichocysts, whereas it does not play a role in exocytosis per se or in the steps immediately following.

Actin Cytoskeleton↗
PubMed1986

Biofeedback of visual evoked potentials.

The present study investigated the operant conditioning of visual evoked potentials within a latency range between 200 and 600 ms using a visual discrimination task, and scrutinized whether biofeedback-induced potential shifts covaried with behavioral responses (reaction time, RT). It could be demonstrated that subjects were able to modify their ERPs towards more or less positivity according to the instruction given. In addition, in could be shown that a biofeedback-induced greater positivity of the P300-complex was highly correlated with a decrease of reaction time. It is hypothesized that this could be due to a modification of P300-components reflecting information processing.

Adult↗
PubMed1984

[Coronary vessel dilatation using guided balloon catheters. Experiences with the first 100 dilatations in stable and unstable angina pectoris].

Between April and December 1983 100 transluminal coronary dilatations in 98 patients were performed using new steerable balloon catheter systems. The primary success rate (diameter enlargement greater than 20%) overall was 87%, in stenoses of the anterior interventricular branch 88.1% (59 out of 67 interventions), in stenoses of the right coronary artery 88.9% (16 out of 18), and in circumflex branch stenoses 84.6% (11 out of 13). Within the first 50 interventions the success rate was 80%. Among the second 50 cases it was improved to 94%, mainly due to the increasing experience of the investigators. Emergency bypass operations had to be performed in two patients in whom coronary vascular occlusion had occurred. No patient died and in only one a small infarction occurred, probably due to occlusion of a side branch with an increase of creatine kinase to a maximum of 120 U/l. These figures show that steerable balloon systems clearly improve the primary success rate despite broadening of indications and diminish serious complications.

Adult↗
PubMed1984

[Determination of the size of the right atrium using two-dimensional echocardiography].

Echocardiographical and functional parameters of the right ventricle have been established. In addition, to improve the analysis of right heart dynamics, normal values for right atrial dimensions and the tricuspid valve anulus diameter are required. We therefore examined 30 normal adult subjects, 15 males (aged 31 +/- 10 years, mean +/- SD) and 15 females (aged 28 +/- 8 years) using two-dimensional echocardiography in the apical 4-chamber view. The contour of the right atrium was delineated with a light pen, and the end-diastolic and end-systolic areas were calculated using a computerized integration method; the percentage area shortening fraction was determined as end-systolic area - end-diastolic area/end-systolic area. The diameter of the tricuspid anulus was measured in the ECG-triggered two-dimensional stop frame; the greatest diameter was reached immediately after the end of the P-wave in the ECG and the smallest diameter at midsystole. Thus it was possible to calculate the anulus shortening fraction as greatest diameter - shortest diameter/greatest diameter. For determination of the circumference of the tricuspid valve anulus a circular geometry was assumed. The mean values, the standard deviation and the 95% upper confidence bound for the 90th percentile were calculated. The end-diastolic right atrial area in the apical 4-chamber view was 3.0 +/- 0.8 cm2/m2 in the whole study group (males 3.4 +/- 1.8 cm2/m2 and females 2.6 +/- 0.5 cm2/m2) and the end-systolic area was 6.9 +/- 1.0 cm2/m2 (males 7.1 +/- 1.1 cm2/m2 and females 6.6 +/- 0.9 cm2/m2); the calculated value of the area shortening fraction was 56.7 +/- 9.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Acyclovir therapy for acute herpes zoster.

31 adults took part in a randomised, placebo-controlled, double-blind trial of intravenous acyclovir therapy (500 mg/m2 intravenously 3 times daily for 5 days) for acute herpes zoster. Acyclovir reduced pain, decreased erythema, prevented the formation of new lesions, and healed skin faster than did placebo. The duration of viral shedding was also significantly shorter in acyclovir recipients (2 days versus 5 days). However, 6(35%) of 17 acyclovir recipients had recurrence of pain after the drug was discontinued, and acyclovir did not appear to affect post-herpetic neuralgia. Acyclovir therapy was associated with a transient rise in serum creatinine levels, and may have been related to nausea and vomiting. Intravenous acyclovir was effective therapy for acute herpes zoster but the ideal treatment regimen might be a lower daily dose given for a longer period.

Acute Disease↗