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Biomedical subjects

R Brunner

Publications and source records attributed to R Brunner.

At least 73 records · Page 4Linked to original sources

Prevention of heterotopic ossification in hip arthroplasties by means of an early single-dose radiotherapy (6 Gy).

Radiotherapy has proven to be efficient in the prevention of heterotopic bone formation. Its importance is increasing in the treatment of uncemented implants in prosthetic hip surgery, where a localized irradiation field is applied to cover the bone-implant interface. In a prospective study the efficiency of two radiation concepts using two different doses to prevent heterotopic ossifications after total hip arthroplasties or revision arthroplasties was compared. In 7 patients after fractioned irradiation (5 x 2 Gy), two recurrences of periarticular ossification occurred, whilst in 17 patients after a single-shot irradiation of 6 Gy on the first postoperative day, no recurrences were seen. There were no side-effects from the radiation. Radiological signs of lucent cement-free implants or delayed wound-healing were absent. Thus, a single shot of 6 Gy applied within 24 h postoperatively reliably prevents heterotopic bone formation. It is safer than 5 x 2 Gy and facilitates the management of the patient.

Aged↗

Circadian variations in antigen-specific proliferation of human T lymphocytes and correlation to cortisol production.

Cortisol is a well-known immunosuppressant when used therapeutically. The present investigation was set out to study if diurnal variations in endogenous cortisol production are reflected by changes in proliferative responses of human lymphocytes to either a mitogen (phytohemagglutinin-A, PHA) or an antigen (tetanus toxoid, TT) stimulus. The study included eight healthy volunteers. Blood was withdrawn at 0200, 0600, 1000, and 1800h for preparation of lymphocytes and determination of cortisol in plasma. Isolated cells were incubated without (baseline activity) or with inclusion of either 1 micrograms PHA or 10 micrograms TT. Proliferation was measured by labelling with 3H-thymidine for 16 h of culture. The cortisol plasma levels exhibited the well known diurnal variations with highest concentrations at 1000h and lowest levels at 0200h. Baseline activity or PHA stimulated cell proliferation did not show significant diurnal fluctuations. The response to TT, however, decreased by 38% between 0600 and 1000h (p = .01). Correlation analyses revealed that the reduction of the proliferative responses to TT correlated significantly (p < .05) with increases in cortisol plasma levels. It was concluded that diurnal fluctuations in the production of endogenous cortisol might be relevant for daytime dependent variations in immune responsiveness.

Adult↗

Electrophysiologic abnormalities in two cases of familial amyloidosis.

PURPOSE/METHODS: We recorded electrophysiologic data of two patients with familial amyloidosis. RESULTS/CONCLUSIONS: Only minor abnormalities could be demonstrated clinically and by means of fluorescein angiography in one patient. Considerable alterations of electrophysiologic responses could be found in both patients. These results suggest that an early retinal or optic nerve involvement in amyloidosis could be detected by using these noninvasive techniques.

Adult↗

[Changes in muscle power following tendon lengthening and tendon transfer].

Each muscle consists of a tendon, the aponeuroses and the muscle fibers. Because of the anatomical architecture a force functionally adapted to the joint motion is generated by the muscle. If the functional length changes, the muscle adapts by altering the number of sarcomeres in a series. If the tendon is elongated without changing the functional range of motion at which the muscle is active on the joint, the passive tension is decreased. As a result, the number of sarcomeres in a series is reduced. The muscle produces less force and the range of active force production is narrowed. If by elongating the tendon, however, the functional range of motion of the muscle at the joint is moved and the tension remains unchanged, the muscle force can be preserved. A tendon transfer affects the muscle in a similar way. If the length of the muscle (and the tension) remains unchanged, the muscle force will be preserved. This prerequisite is fulfilled even better the more the architecture of the replacing muscle equals what is being replaced.

Biomechanical Phenomena↗

Change in hemorrheological and biochemical parameters following membrane differential filtration.

INTRODUCTION: The elimination of high molecular weight proteins may have a positive influence on disorders of the microcirculation due to an improvement in rheological parameters. We therefore attempted to evaluate the rheological efficacy of membrane differential filtration (MDF). PATIENTS AND METHODS: Ten patients suffering from macular disease underwent MDF. Rheological and biochemical parameters as well as visual acuity were determined one day before and after therapy: The study aimed at a reduction in plasma viscosity, standardized whole blood viscosity at hematocrit 0.45 and erythrocyte aggregation at hematocrit 0.3. RESULTS: Severe side-effects were not observed. The rheological parameters were significantly reduced. In detail the posttreatment values were reduced as compared to the pretreatment values as follows: plasma viscosity 85%, standardised whole blood viscosity 86% (hematocrit 0.45), erythrocyte aggregation 59% (hematocrit 0.3), total protein 81%, IgG 66%, IgA 59%, IgM 33%, alpha-2-macroglobulin 30%, triglycerides 102%, total cholesterol 47%, VLDL cholesterol 94%, LDL cholesterol 33%, HDL cholesterol 62%. Visual acuity was improved in 7/10 patients. CONCLUSIONS: MDF is a safe and highly effective method for lowering biochemical and improving rheological parameters which led to improvement in visual acuity. We have already replaced plasma exchange with MDF in our clinical practice of hemorrheological therapy.

Aged↗

The bovine lactoferrin gene (LTF) maps to chromosome 22 and syntenic group U12.

Five overlapping lambda EMBL-clones, containing the complete bovine lactoferrin gene (LTF), have been used to map this gene by fluorescence in situ hybridization to bovine Chromosome (Chr) band 22q24. Primers derived from promoter and exon I sequences were applied in polymerase chain reactions (PCRs) to DNA samples of a previously characterized panel of somatic cell hybrid lines, allowing the assignment of the bovine lactoferrin locus to syntenic group U12. These results permit the assignment of syntenic group U12 to bovine Chr 22.

Animals↗

[Digital data collection and analysis in clinical electrophysiology. A PC program for electrophysiology].

BACKGROUND: The number of data acquired in electrophysiology and the need for immediate analysis and interpretation justified the use of computerized signal acquisition and -analysis. Since such techniques are well known and established in computerized perimetry, the user of EOG, ERG, and VEP will profit from such an approach. METHOD: A computer program for signal acquisition and -analysis of clinical electrophysiology is described. The software is written in BASIC for IBM compatible PC/XT/AT computers. The program supports all electrophysiological examinations (EOG, ERG, VEP). It contains a subroutine for automated EOG recording and -analysis, allows measurements of amplitude and latency of standardized Ganzfeld-ERG and pattern-ERG. Options for recording and analysis of further stimuli are prepared. The possibility of determination of area under the curve is implemented. In the VEP subroutine evaluation of amplitude, latency, area under the curve, and Fast-Fourier-Transformation--necessary for steady-state-VEP--is installed. CONCLUSION: The program demonstrates that with the now available low cost Personal Computer technology it is possible to build up individual software systems for clinical electrophysiology supporting and optimizing all recording, analysing, and administrative procedures.

Data Collection↗

P-glycoprotein expression as unfavorable prognostic factor in acute myeloid leukemia.

In order to further define the role of the MDR1 gene in acute myeloid leukemia (AML), we determined the association between the presence of P-glycoprotein on leukemic cells and the efficacy of therapy in patients with AML. Immunocytochemistry with monoclonal antibody C219 was performed to demonstrate the presence of P-glycoprotein. Positive staining ranged from 0 to 60% of the leukemic cells. For further analysis, patients were assigned into groups with 0-5% staining cells (group 1, n = 33) and with > 5% staining cells (group 2, n = 19). The complete remission rate of induction chemotherapy was 76% for group 1 but only 32% for group 2 (p = 0.002). The median duration of overall survival was 19 months for patients in group 1 as compared to 3 months for patients in group 2 (p = 0.007). The data indicate that P-glycoprotein expression is associated with an unfavorable prognosis in patients with AML.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Reproducibility and intraindividual variability of the pattern electroretinogram.

The human pattern electroretinogram (PERG) is a contrast-specific potential presumedly reflecting the functional integrity of ganglion cells. Many studies have devised criteria that enable PERG measurements to distinguish established glaucomatous (hypertonic) eyes from normal controls. As there are relatively few reports concerning the reproducibility and reliability of the PERG, we studied the intraindividual variability of the PERG in 20 healthy subjects. Both transient and steady-state responses were recorded using a high-contrast (98%), black-and-white, counterphasing checkerboard pattern (average luminance, 80 cd/m2) generated by a television monitor (subtending angle, 13.8 degrees x 10.8 degrees) using three different check sizes (15', 30', and 60'). Recordings were performed in both eyes simultaneously at a 7-day interval under test-retest conditions. Responses of 30' spatial frequency were most consistent and resulted in a mean amplitude (+/- SD) of 2.18 +/- 0.95 microV (P50) and 4.00 +/- 1.69 microV (N95) for transient patterns and 1.84 +/- 1.25 microV for steady-state patterns. No statistically significant difference was observed between either right and left eyes, test and retest conditions or 1st- and 7th-day recording sessions for PERG parameters. In linear correlation analysis there was an adequate, positive correlation between the right and left eyes (r = 0.78); a weak correlation between test and retest conditions (r = 0.58); and no correlation between measurements made at a 7-day interval. As a consequence, we conclude that the follow-up of patients (e.g., glaucoma, ocular hypertension) by means of PERG is critical, especially when therapeutic consequences may be based on the physiological variability of a weak retinal signal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Is general anaesthesia necessary to record reproducible electroretinograms in rabbits?

In toxicity testing of intraocularly applied substances the flash electroretinogram (ERG) serves as an indicator of intact or reduced retinal function in the animal. Insufficiently monitored narcosis may be a source of puzzling ERG results. We performed electroretinography in 25 dark-adapted rabbits without general anaesthesia to evaluate the reproducibility of that method. Two recordings obtained at a mean interval of 26.87 days were compared. The scotopic a- and b-waves showed the same characteristics concerning shape, amplitude and implicit time known from other publications dealing with ERG recordings in narcotised rabbits. No statistically significant difference could be found between the test and retest recordings. It could be demonstrated that narcosis is not necessary for recording of stable and reproducible scotopic ERGs in rabbits.

Anesthesia, General↗

Atypical presentations of Best's vitelliform macular degeneration: clinical findings in seven cases.

The clinical findings obtained in seven patients from four families with atypical vitelliform macular degeneration are described. Five patients had an onset of the disease in childhood and two patients, at the age of 45 years. Their visual acuity was mildly reduced (0.52 +/- 0.27). The fundus showed variable changes with single or multiple central or paracentral yellowish subretinal exudates and deposits, sometimes surrounded by scars. Both eyes were affected in all patients. The scotopic and photopic electroretinograms were normal in all cases. The electrooculogram (EOG) showed a significant reduction of the light rise in all affected eyes, and in five eyes a reduction in the dark trough could be observed. In three clinically unaffected first-order relatives with normal fundus appearance, the light rise of the EOG was reduced, thus identifying them as gene carriers. The clinical features of atypical vitelliform macular degeneration are discussed with respect to similar diseases that must be excluded and may give reason for misdiagnosis.

Child↗

[Sinus tarsi syndrome. Results of surgical treatment].

Following exclusion of other causes of pain debridement of the sinus tarsi was carried out in 47 hindfeet with persisting pain despite local infiltration with steroids. In 41 patients with a total of 42 feet treated this way, evaluation by a research questionnaire was possible: 15 patients had some persistent problems or had inadequate results after surgery, and in 13 of these a clinical follow-up examination was carried out. Our retrospective study confirms that surgery is successful in treating chronic pain syndromes in the region of the sinus tarsi, as is known from the literature. It is especially successful if the pain is not due to an earlier fracture. In 60% of the hindfeet an instability required a ligamentous reconstruction is found on surgery. This high percentage suggests that the development of the sinus tarsi syndrome may quite often be due to an instability in the hindfoot.

Adolescent↗

[Disordered alpha 2-adrenoreceptor function in hemodialysis patients with renal anemia--a possible cause of increased blood pressure in relation to recombinant human erythropoietin?].

Nine patients on maintenance hemodialysis and transfusion-demanding renal anemia (group A) were treated with rHuEPO 120 IU/kg i.v. three times per week. Hemoglobin-content was raised from 7.2 +/- 0.9 to 10.4 +/- 0.8 g/dl. In all patients blood pressure rose, three patients developed arterial hypertension. Mean diastoloic blood pressure was 66 +/- 12 and 78 +/- 16 mmHg (p less than 0.001) before and after rHuEPO. Rise in blood pressure was accompanied by a significant fall in plasma-noradrenaline-levels (from 498 +/- 100 to 383 +/- 75 pg/ml; p less than 0.05) and alpha 2-adrenoceptor-density (from 574 +/- 76 to 384 +/- 49; p less than 0.05). Compared to nine patients on maintenance hemodialysis and hematocrit over 30% (group B), patients with severe renal anemia (group A before treatment) had higher densities of alpha 2-adrenoceptors (574 +/- 76 vs. 218 +/- 32; p less than 0.001) despite higher plasma-noradrenaline-levels (498 +/- 100 vs. 399 +/- 63; n.s.). We suppose a anemia-related disturbance of alpha 2-receptor-function with the result of abolished receptor down-regulation and impaired vascular reagibility to vasoconstricting stimuli. With the correction of anemia receptor-function improves, receptor down-regulation as well as vascular reagibility is re-established resulting in augmented vascular resistance and higher blood pressure.

Adult↗

Repair of fibular ligaments: comparison of reconstructive techniques using plantaris and peroneal tendons.

The results of treatment of chronic ligamentous insufficiency of the lateral hindfoot using plantaris tendon grafting (52 ankles) or peroneal tenodesis (128 ankles) were compared with an average followup of 66 months. In two-thirds of all cases an instability of the subtalar joint was present, isolated or combined with an instability of the talocrural joint. The overall outcome with both methods was good, but the results after plantaris repair were slightly more favorable. This fact is underlined by the frequency of reoperations: 1.9% after plantaris repair compared with 9.4% after peroneal tenodesis. We conclude that plantaris repair is the method of choice.

Adolescent↗

Changes in the alpha adrenergic system and increase in blood pressure with recombinant human erythropoietin (rHuEpo) therapy for renal anemia.

Recombinant human erythropoietin (rHuEpo) is effective in correcting renal anemia with the development of hypertension as the most frequent side-effect. Compared to hemodialysis patients with normal hemoglobin concentration, nine examined patients with transfusion-dependent renal anemia had low blood pressure in the context of high alpha 2-receptor densities and high plasma levels of catecholamines. This constellation can be explained by a defective receptor-ligand-interaction. During treatment with rHuEpo all patients showed an increase in blood pressure due to increased peripheral resistance, accompanied by a significant fall in plasma noradrenaline and alpha 2-receptor-density. There was a significant negative correlation between hemoglobin concentration and alpha 2-receptor density. We conclude that correction of renal anemia abolishes anemia-mediated disturbance of alpha 2-receptor function with the consequence of receptor down-regulation and increased vasoconstriction, which contributes to the rise in arterial blood pressure.

Adult↗