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Biomedical subjects

R Zehnder

Publications and source records attributed to R Zehnder.

14 recordsLinked to original sources
PubMed2000

Elevation of soluble Fas and soluble Fas ligand in reactive macrophage activation syndromes.

Derailed T-cell activation can give rise to life-threatening macrophage activation, the final common pathway of the different forms of reactive macrophage activation syndromes (rMAS). Besides inappropriate activation of the immune system, impaired termination of immune responses might be another mechanism leading to rMAS. The Fas (CD95)/Fas ligand (CD95 ligand) system functions in turning off immune responses by executing activation-induced cell death (AICD). Soluble Fas (sFas) and Fas ligand (sFasL) can interfere with their corresponding membrane-bound counterparts, qualifying them as potential parameters of impaired immune termination. Hence, sFas and sFasL were analyzed in sera of rMAS patients. We show that soluble Fas/CD95 (sFas) is elevated >2 SD over the mean of controls in all 8 rMAS episodes studied (mean 12.08 +/- 6.12 ng/mL, range 3.7-20.2; controls 2.46 +/- 0.49, range 1.5-2.9). sFasL was detected during five rMAS episodes (0.70 +/- 0.49 ng/mL, range 0.16-1.28; controls all below the limit of detection of 0.1). In addition, both parameters decrease during convalescence, reflecting clinical evolution. In conclusion, sFas seems to be consistently elevated during acute rMAS. sFasL is detected only in a subgroup of our adult rMAS patients extending the recent finding of sFasL elevation in a majority of children with macrophage activation syndromes (Hasegawa et al. Blood 1998;91(8):2793-2799). By interfering with AICD, sFas and sFasL might contribute to the pathogenesis of at least a subset of rMAS.

Adult↗
PubMed1997

Qualitative assessment of blood washing with the continuous autologous transfusion system (CATS)

A number of different blood-processing methods can be used at the end of cardiopulmonary bypass (CPB) to improve the quality of autologous blood. They include centrifugation, hemofiltration and cell-washing. They differ in processing time required, cost of disposables and the quality of the processed autologous blood product. The newly developed continuous auto-transfusion system (CATS: Fresenius AG, Bad Homburg) uses a continuous cell-washing method. In a prospective study, the oxygenator blood of 10 patients was processed at the end of cardiac surgery with CATS and the quality of autologous blood before and after processing was compared. The processing volumes and the time required were recorded. The concentrations and elimination rates of blood parameters and waste products such as activated coagulation and complement products were measured. At the end of CPB a mean volume of 1,010 +/- 174 ml diluted oxygenator blood was processed and concentrated to 310 +/- 88 ml in 11.0 +/- 2.2 mins. Cellular elements such as erythrocytes and leucocytes were mostly retained and their concentration showed a significant increase after processing (250% and 210% respectively; p < 0.01). Thus, the blood processing with CATS resulted in an excellent hemoconcentration (hematocrit 62 +/- 3 vs. 24 +/- 4% before processing) with a consistent reproducibility. On the other hand, the CATS concentrate showed a significant loss of autologous plasma proteins. Likewise, all water soluble elements such as waste products are significantly lower in concentration after processing and, if calculated by quantity, they show a high elimination rate (> 93%). In conclusion, the continuous autologous transfusion system permits an automated, rapid and continuous processing of autologous blood yielding a standardised high quality erythrocyte concentrate.

Aged↗
PubMed1988

Functional diagnostics of the cervical spine using computer tomography.

35 healthy adults and 137 patients after cervical spine injury were examined by functional CT. The range of axial rotation at the level occiput/atlas, atlas/axis and the segment below were measured in all subjects. A rotation occiput/atlas of more than 7 degrees, and C1/C2 more than 54 degrees could indicate segmental hypermobility, a rotation at the segment C1/C2 less than 29 degrees to hypomobility. According to the postulated normal values based upon a 98% confidence level, out of 137 patients examined after cervical spine injury and with therapy-resistant neck pain, 45 showed signs of segmental hypermobility of the upper cervical spine, 17 showed hyper- or hypomobility at different levels, 10 patients presented segmental hypomobility at C1/C2 level alone. In all patients, according to the clinical assessment, functional pathology was suspected in the upper cervical spine. Surgical correction of rotary instability should be considered as a possible therapeutic procedure after successful diagnostic stabilisation of the cervical spine by minerva cast.

Adolescent↗
PubMed1987

CT-functional diagnostics of the rotatory instability of the upper cervical spine. Part 2. An evaluation on healthy adults and patients with suspected instability.

Nine healthy adults and 43 patients with cervical spine injury were examined by using functional (computerized tomography) CT scanning. The ranges of axial rotation at the levels occiput C0-C1, C1-C2, and C2-C3 were measured. A rotation at C0-C1 greater than 8 degrees; at C1-C2, 56 degrees; or a right-left difference C0-C1 greater than 5 degrees and C1-2 greater than 8 degrees indicates hypermobility. A rotation at segment C1-C2 of less than 28 degrees indicates hypomobility. Surgical stabilization of rotatory instability could be considered as a possible therapeutic procedure.

Adolescent↗
PubMed1987

The subcoracoid space. An anatomic study.

Soft tissue impingement under the coracoid process has recently been identified as a cause of painful shoulder disability. In this study the normal space between the humeral head and the coracoid process in two functional positions of the arm was measured in an attempt to delineate anatomic risk factors predisposing to subcoracoid impingement. Forty-seven normal shoulders were studied by computerized tomography (CT) in adduction, 20 additionally in forward flexion/internal rotation, which is the position most frequently causing subcoracoid impingement. The distance between the humeral head and the coracoid tip averaged 8.7 mm for the adducted arm and 6.8 mm for the flexed arm. Modifications of the coracohumeral relationship were found to affect the subcoracoid clearance roughly 1.5 times more in flexion than with arm at the side. Subcoracoid impingement appeared particularly likely during forward flexion of a shoulder with a coracoid tip close to the scapular neck and projecting far laterally.

Adult↗
PubMed1986

[Post-traumatic osteitis following severe soft tissue and skeletal injuries of the distal lower leg and foot].

Complications after severe soft tissue- and skeletal injuries of the distal lower leg and foot are frequent. The incidence of infection is outlined on the basis of the AO-Documentation-Center in Berne. In case of infection, necrotic tissue must be eliminated and stability of the fracture has to be maintained. Cancellous bone grafts as well as microvascular plastics should only be considered in the presence of a well vascularized fracture-bed. The benefit of antibiotics and disinfectants and the interrelation between infection and allergy to implants are discussed.

Anti-Bacterial Agents↗
PubMed1985

The lower-extremity musculature in chronic symptomatic instability of the anterior cruciate ligament.

We studied the musculature of the lower extremity in forty-one patients with chronic symptomatic instability of the anterior cruciate ligament. Computed tomographic and clinical measurements of the limb were taken at levels fifteen and twenty-five centimeters proximal to the medial joint line and ten centimeters distal to it. Biopsy specimens from the vastus lateralis of both lower extremities were analyzed by histochemistry and electron microscopy. Computed tomography revealed a decrease in the muscle square area of the affected thigh of 8 per cent as compared with the control lower extremity. There was quadriceps atrophy of 10 per cent and hamstrings atrophy of only 4 per cent. The atrophy of the vastus medialis was significantly greater than that of the entire quadriceps. Histochemistry revealed a similar decrease in fiber size for all fiber types, and hence no shift in fiber type. Electron microscopy showed an increase in intracellular fat but no change in mitochondrial volume density or capillarization.

Adolescent↗
PubMed1975

[The consumption of alcohol, drugs and the smoking habits of 4,082 healthy young Swiss men as evidenced by a random study].

By means of written questionnaires and (with every third or fourth subject, selected at random) standardized interviews, 4082 recruits from various regions of Switzerland were asked about their alcohol and drug consumption and smoking habits in civilian life. To estimate the consumption pattern during military training all recruits still available towards the end of military service (64.3 percent) were questioned again regarding intake of alcohol, tobacco and drugs during military service. The inquiry showed that in civilian life only 10.4 percent were alcohol abstainers, 39.8 percent were non-smokers and 77 percent had no drug experience. 8.6 percent reported a weekly alcohol consumption of more than 350 g alcohol 100 percent (an amount corresponding to 9 1 beer, 41/2 1 wine, 1 1 brandy), 17.4 percent had smoked more than 24 g tobacco per day (corresponding to more than 24 cigarettes daily), and 10.6 percent had taken drugs more than 6 times in their lives. The study was also designed to demonstrate the relations between family or socioeconomic data and intake of alcohol, tobacco and drugs. It was found that French and Italian speaking recruits indicated a higher alcohol consumption, that the lower socioeconomic class was exposed to be greater risk with regard to alcohol and tobacco consumption and the separately interviewed group of pupils to the greatest risk of drug experinece. Sons of divorced or separated parents, of parents married after the subject's birth or of parents who are heavy alcohol, tobacco or medicament consumers represent a higher percentage among the highest consumption class for alcohol, tobacco and drugs than subjects who had grown up in stable families or whose parents had been non-consumers or only moderate consumers of alcohol, tobacco or drugs. Finally, a correlation was also found between use of leisure time and alcohol, tobacco and drug consumption. It was in the groups of recruits who spent their spare time rather passively that the highest percentage of subjects in the upper consumption classes for alcohol, tobacco and drugs was observed. During military training consumption patterns withregard to alcohol and tobacco hardly changed, and only a small number of subjects (7.7 percent of 2587) took drugs during this time.

Adult↗