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Biomedical subjects

E Müller

Publications and source records attributed to E Müller.

At least 181 records · Page 10Linked to original sources

Rapid adaptation to eccentric exercise-induced muscle damage.

This study examined eccentric exercise-induced muscle damage and rapid adaptation. Twenty-two male subjects performed 70 eccentric actions with the knee extensors. Group A (n = 11) and group B (n = 11) repeated the same exercise 4 and 13 days after the initial bout, respectively. Criterion measures included muscle soreness, muscle force generation (vertical jump height on a Kistler platform), and plasma levels of creatine kinase (CK), slow-twitch skeletal (cardiac beta-type) myosin heavy chains (MHC), and cardiac troponin I. Subjects were tested pre-exercise and up to day 4 following each bout. The initial exercise resulted in an increase in CK and MHC, a decrement in muscle force, and delayed onset muscle soreness in all participants. CK and MHC release correlated closely (rho = 0.73, p = 0.0001), both did not correlate with the decrement in muscle force generation after exercise. Because cardiac troponin I could not be detected in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for a injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Repetition of the initial eccentric exercise bout after 13 days (group B) did not cause muscle soreness, a decrement in muscle reaction force with vertical jump or significant changes in plasma MHC and CK concentrations, whereas in case of repetition after 4 days (group A) only the significant increases in CK and MHC were abolished. The decrement in reaction force with vertical jump did not differ significantly from that after the initial exercise session, but perceived muscle soreness was less pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗

[Treatment of postoperative shivering with nalbuphine].

OBJECTIVE: Postoperative shivering is common and has potentially adverse side effects in high-risk patients. Meperidine, which binds to both mu- and kappa-opioid receptors, is reported to be more effective in treating shivering than morphine or fentanyl. Recent data indicate that much of meperidine's special antishivering effect may be mediated by its kappa-opioid receptor activity. Nalbuphine, an opioid agonist/antagonist also has a potent affinity for kappa-receptors. The aim of this study was to evaluate the antishivering effect of nalbuphine in comparison to meperidine. METHODS: 100 ASA physical status I-II patients shivering after elective surgery were included in the study. General anaesthesia was performed with thiopentone, low-dose fentanyl and enflurane in N2O/O2. After arrival in the recovery room patients shivering within 5 min received either meperidine 25 mg or nalbupine 10 mg in a double-blind, randomised manner. The duration and severity of shivering, heart rate, respiratory rate, blood pressure, end-tidal CO2 concentration, O2-saturation and awareness were documented until 20 min after injection. Patients in need of a second injection were excluded from the study. RESULTS: Demographic variables, duration of operation and temperature decreases were not significantly different between treatment groups. The suppression of shivering was achieved within 4.0 +/- 3.5 or 4.6 +/- 4.1 min following the injection of meperidine or nalbuphine, respectively (p = NS). Vital signs and postoperative vigilance showed no significant differences. No adverse side effects were observed. DISCUSSION: The data indicated that nalbuphine suppressed postoperative shivering as effectively and timely as meperidine in equianalgesic doses. The observation is consistent with the hypothesis that stimulation of kappa-opioid receptors is a likely explanation for much of meperidine's antishivering action.

Adult↗

Cerebral arteriovenous malformations: flow quantitation by means of two-dimensional cardiac-gated phase-contrast MR imaging.

PURPOSE: To test two-dimensional cardiac-gated phase-contrast (2DGPC) magnetic resonance (MR) imaging in the evaluation of cerebral arteriovenous malformations (AVMs) and the alterations in flow that accompany embolization therapy. MATERIALS AND METHODS: A 2DGPC sequence was used to measure flow velocity in the feeding vessels and corresponding contralateral vessels (CCVs) of seven patients (six men and one woman, 21-55 years of age; mean, 37 years) with cerebral AVMs and in the vessels of four healthy volunteers (all men; mean age, 22 years). RESULTS: In the patients, the flow in the feeding vessels exceeded the flow in the CCVs by a margin far greater than the asymmetry in flow in the volunteers. The mean reduction in flow after embolization was 54.9% +/- 11.1 in embolized feeding vessels (n = 6) and 5.3% +/- 2.8 in nonembolized vessels (n = 3). Postembolization flow enhancement was observed in the CCV (n = 2), which suggests a degree of autoregulatory dysfunction. CONCLUSION: This technique can be used to evaluate the flow patterns of AVMs and the hemodynamic changes that occur with embolization.

Adult↗

Frequency of common cystic fibrosis gene mutations in chronic bronchitis patients.

It has been suggested that the delta F508 deletion, the most common mutation in the cystic fibrosis (CF) gene, might be linked to chronic bronchial hypersecretion. We investigated whether such an association could be found in chronic bronchitis, since chronic bronchial hypersecretion is an important and specific element of chronic bronchitis. We screened 100 patients hospitalized for chronic bronchitis with six of the most frequently occurring CF gene mutations: delta F508, R553X, G542X, G551D, N1303K, and 621-1G-->T. Only one patient affected by chronic bronchitis and diffuse bronchiectasis was heterozygous for the deletion delta F508; no other mutations were found. This is not significantly different from the expected frequency of CF carriers in northern Europe, which is 1 in 25. Thus, no association between the most commonly occurring cystic fibrosis genes and chronic bronchitis is likely to exist and routine screening of patients without further signs of cystic fibrosis would seem to be of no benefit in northern Europe.

Aged↗

IFN-gamma up-regulates platelet-activating factor receptor gene expression in human monocytes.

Human monocytes constitutively express the platelet-activating factor receptor (hPAF-R). In this report, we have investigated the modulation of hPAF-R by IFN-gamma. Treatment of monocytes with IFN-gamma caused a time- and concentration-dependent accumulation of hPAF-R mRNA. In contrast, IFN-alpha was inactive. The effect of IFN-gamma was rapid, evident by 1 h of stimulation and reaching a maximum after 2 h. The high level of hPAF-R mRNA was maintained for at least 24 h. Flow cytometry analysis revealed that monocytes treated with IFN-gamma had a two- to sixfold increase in PAF receptor expression at the cell surface, when compared with untreated cells. The increase in hPAF-R expression was associated with an augmented response of IFN-gamma-treated cells to PAF in terms of cytosolic calcium ([Ca2+]i) variations. The IFN-gamma-dependent accumulation of hPAF-R mRNA was not due to the stabilization of hPAF-R mRNA, as shown by unchanged hPAF-R mRNA t1/2. Pretreatment of monocytes with actinomycin D, however, completely abrogated the effect of IFN-gamma, suggesting a transcriptional regulation. Moreover, the up-regulation of hPAF-R mRNA by IFN-gamma was independent of de novo protein synthesis since cycloheximide, an inhibitor of protein synthesis, did not affect this up-regulation. These studies are the first report showing that IFN-gamma regulates hPAF-R gene expression in human monocytes, by a mechanism suggesting transcriptional regulation. This may represent a prototypic example of regulation by lymphocyte-derived cytokines of lipid mediator receptors in myeloid cells, thus adding a novel element in the interrelationship between immune and inflammatory responses.

Base Sequence↗

Functional 2D and 3D magnetic resonance imaging of motor cortex stimulation at high spatial resolution using standard 1.5 T imager.

This paper reports the effects of motor cortex stimulation of normal volunteers using conventional MR imaging techniques on standard 1.5 T clinical scanner. Improvement in signal-to-noise (S/N) ratio has been achieved by using a commercially available eye/ear surface coil with a loop of 8.5 cm in diameter. Magnet shimming with all first order coils was performed to the volunteer's head resulting in a magnetic field homogeneity of about 0.1-0.2 ppm. The imaging technique used was an optimized conventional 2D and 3D, first order flow rephased, gradient-echo sequence (FLASH) with fat-suppression and reduced bandwidth (16-28 Hz/pixel) and TR = 80-120 ms, TE = 60 ms, flip angle = 40 degrees, matrix = 128 x 128, FOV = 150-250 mm, slice-thickness = 2-5 mm, NEX = 1, and a total single scan time for one image of about 12-16 s. In the 3D FLASH measurements, a slab of 32 mm thickness with 16 partitions was evaluated. The motor cortex stimulation was achieved by touching each finger to thumb in a sequential, self-paced, and repetitive manner. During stimulation, an increase in signal of order 10-20% was detected in the motor and sensory cortex due to reduced partial volume effects and optimized S/N for the measurements at small voxel size. 3D FLASH imaging at high spatial resolution shows good anatomical correlation of signal increase with gray matter of the motor and sensory cortex. The reported data demonstrate the technical feasibility of functional 2D and 3D MR imaging at high spatial resolution using optimized conventional sequences and equipment.

Humans↗

The pulmonary artery acceleration time determined with the MR-RACE-technique: comparison to pulmonary artery mean pressure in 12 patients.

The goal of our study was to evaluate a rapid noninvasive MR technique for quantification of the pulmonary artery acceleration time (PAT) and other parameters of pulmonary hemodynamics and to correlate with pulmonary artery mean pressure (mPAP). The PAT known as "time-to-peak" out of Doppler echocardiographic measurements normally shows significant inverse correlation with mPAP. With the MR-RACE-Technique (RACE: Real time ACquisition and Evaluation of motion) blood velocity measurements can be obtained with a total acquisition time of a few seconds. The application of this technique to the pulmonary artery has not been reported before. Out of the RACE velocity wave form PAT can be obtained with a temporal resolution of about 15 ms. To explore the relationship between PAT and mPAP, right heart catheterization and MR-RACE measurements were performed in 12 patients with different pulmonary vascular abnormalities. Results of MR-RACE were compared with those of mPAP measured by right heart catheter and showed significant inverse correlation (r = -0.82, p = .0011, n = 12). The ability of MR-RACE to enable measurements of blood flow with profiles may be important for characterizing pulmonary and cardiovascular abnormalities.

Aged↗

Extension of the 2-deoxyglucose method to the fetus in utero: theory and normal values for the cerebral glucose consumption in fetal guinea pigs.

Fetal cerebral metabolism changes during development. The normal fetal metabolic rate must be known to evaluate pathophysiological changes. Therefore, we determined the regional cerebral glucose consumption in the fetal guinea pig. This required the application of the 2-deoxyglucose method to this species. We measured both the transfer coefficients of deoxyglucose and glucose between the maternal arterial plasma and the fetal brain and the lumped constant in chronically prepared undisturbed guinea pig dams using a three-compartment model. Furthermore, the ratio between the initial clearances of deoxyglucose and glucose between the maternal arterial plasma and the fetal brain and the ratio between the phosphorylation coefficients of these substrates in the fetal brain were determined. The total cerebral glucose consumption measured by the deoxyglucose method (10 +/- 1.2 mumol/100 g/min) was similar to that calculated from the glucose concentration and the phosphorylation coefficient of glucose in the cerebrum (10 +/- 0.4 mumol/100 g/min). We conclude that the 2-deoxyglucose method is applicable to the guinea pig, and we further conclude that in the fetal guinea pig cerebral glucose consumption is 10 times lower than that in the adult.

Animals↗

[New perspectives in color ultrasound in breast diagnosis].

In recent years, ultrasound has become established as part of the diagnostic evaluation of breast tumours. Not replacing, but complementing mammography, ultrasonic investigations increasingly represent a sensitive means of early diagnosis. Thermography, on the other hand, has proved of relatively little value and doesn't play a significant role today. Lately, Colour Doppler sonography has been used for differentiating tumour-associated blood supply patterns--however, sensitivity and specificity were not as high as initially expected. Colour spectrum analysis of local findings in comparison to the remaining glandular tissue, however, seems to be a promising method in the differentiation of ultrasound findings of uncertain tumour status. A fibroadenoma shows no significantly different colour density as compared to surrounding tissue. In carcinoma, on the other hand, one regularly finds a hyperintensive zone with sharp margins. In 70 patients, who had breast tumours, we attempted the differentiation of benign and malignant findings with the help of colour spectrum analysis. Postoperatively, these results were validated by histology. With the exception of one mesenchymal tumour, the Doppler diagnosis was identical to the histopathological findings.

Breast↗

Analysis of the biomechanical characteristics of different swinging techniques in alpine skiing.

As a consequence of the increase in popularity of skiing as a leisure sport, ski teaching has become an important pedagogic and economic issue. Unfortunately, most ski teaching curricula lack a thorough evaluation of the most important swinging techniques. Therefore, this study analyses the biomechanical characteristics of swinging techniques in alpine skiing. The data were collected using biodynamic, kinematic and electromyographic methods, employing 21 test skiers, all of whom were state-certified Austrian ski instructors. For all techniques, the individual turns were divided into a steering phase and an initiation phase. In the main, the fundamental differences between the single techniques became apparent in the initiation phase. There it seemed useful to distinguish between turns with 'up-unweighting' and turns with 'down-unweighting'. It was found that turns with up-unweighting were initiated either from the downhill ski only or from both skis. Turns with down-unweighting were used primarily on mogul pistes and in deep powder snow. Finally, some conclusions for training methodology are given.

Acceleration↗

X linked Charcot-Marie-Tooth disease (CMTX1): a study of 15 families with 12 highly informative polymorphisms.

X linked dominant Charcot-Marie-Tooth disease (CMTX1) has previously been localised to Xq13-21. Fifteen families were studied using 12 highly informative polymorphisms in the pericentric region of the X chromosome. Phase known recombinations in these families localise the X linked dominant CMT gene to the region distal to DXS106 (Xq11.2-12) and proximal to DXS559 (Xq13.1). These markers flank approximately 2 to 3 Mb of DNA to which GJB1 and CCG1 have already been mapped. A recent report of mutations in the GJB1 gene in subjects with CMTX1 makes this a strong candidate gene.

Cell Cycle↗

[The MR phase contrast method. Determination of blood flow velocity and flow profile of intracranial arteries].

2D-phase-contrast mapping is a MR method that allows for quantitative measurements of blood flow velocity in intracranial vessels. Using a modified FISP-Sequence with a 1.5 T MR scanner, flow studies were carried out on a phantom. Two matrix sizes (256 x 256 vs. 256 x 512) were compared. In 20 healthy volunteers blood flow velocity and profile of the basal (BA), middle cerebral (MCA), and anterior cerebral artery (ACA) were compared with the corresponding findings of transcranial Doppler (TCD) sonography. 2DPK and TCD yielded equivalent velocity data and profiles of the BA. The blood flow velocity in the MCA determined by 2DPK was lower than the TCD values. Using a 256 x 512 matrix, the acquired data were in better accordance with the TCD findings. Due to significant noise measurements of the ACA and PCA were frequently degraded.

Basilar Artery↗

[Suicide incidence and suicide methods in Saxony 1830-1990].

One of the highest rates of suicide occur in German-speaking countries and particularly in Saxonia. There are grounds for the assumption that the fact has been caused by a careful recording of suicides in this country since 1829. The paper describes the development of rates of suicide and the changes of the suicidal methods in Saxonia during the last one-hundred- and -fifty years with regard to age and sex.

Adolescent↗

[Functional imaging of the human brain with conventional MRI].

It was shown in 1991 by Belliveau and co-workers that the activation of the human brain can be visualized in a completely noninvasive way by MRI. First publications coming from the US claimed that very high magnetic field strength or echo planar imaging, both available only at a few research sites, would be necessary to do this job. Recently, it was demonstrated that functional imaging of the human brain can be done with high spatial resolution MRI using conventional FLASH-sequences with the commercial widely available 1,5 Tesla systems. First results have been reported for visual as well as primary motor cortex activation in healthy volunteers. The key to a successful application of the conventional technique lies in the design of extremely low bandwidth, long echo-time FLASH-sequences with high spatial resolution.

Adult↗

[Detection of toxin-producing strains of Pasteurella multocida in nasal and tonsil swabs, a possibility for the control of atrophic rhinitis in swine breeding herds? Parallel comparison with other research methods].

Nasal, and partly tonsil swabs from pigs have been investigated by cell culture and ELISA respectively on toxigenic Pasteurella multocida strains. The controlled animals are from 89 non atrophic rhinitis- and 42 a.r.-positive herds. Toxin forming strains could not be isolated in non suspicious herds. 23 out of 42 infected herds showed toxigenic Pasteurellae. Despite a high increase in sample numbers, Pasteurella could not be detected in 19 infected herds (45%). When diagnosing atrophic rhinitis, we thus recommend to rely only on positive results of isolation. In all other cases, all other methods will have to be used in combination. Further research is necessary to find safe and fast test methods. According to recent experience, the blood-serological toxin screening test can be considered useful.

Animals↗