Search PubMed⌕ Search

Biomedical subjects

E Müller

Publications and source records attributed to E Müller.

At least 73 records · Page 4Linked to original sources
PubMed2000

Radio Emission from Three-dimensional Relativistic Hydrodynamic Jets: Observational Evidence of Jet Stratification.

We present the first radio emission simulations from high-resolution three-dimensional relativistic hydrodynamic jets; these simulations allow us to study the observational implications of the interaction between the jet and the external medium. This interaction gives rise to a stratification of the jet in which a fast spine is surrounded by a slow high-energy shear layer. The stratification (in particular, the large specific internal energy and slow flow in the shear layer) largely determines the emission from the jet. If the magnetic field in the shear layer becomes helical (e.g., resulting from an initial toroidal field and an aligned field component generated by shear), the emission shows a cross section asymmetry, in which either the top or the bottom of the jet dominates the emission. This, as well as limb or spine brightening, is a function of the viewing angle and flow velocity, and the top/bottom jet emission predominance can be reversed if the jet changes direction with respect to the observer or if it presents a change in velocity. The asymmetry is more prominent in the polarized flux because of field cancellation (or amplification) along the line of sight. Recent observations of jet cross section emission asymmetries in the blazar 1055+018 can be explained by assuming the existence of a shear layer with a helical magnetic field.

Journal Article↗
PubMed2000

Maculo-papillary branch retinal artery occlusions following the Wada test.

BACKGROUND: The Wada test induces short-term anesthesia of one hemisphere by injection of sodium amytal into an internal carotid artery. It is an important presurgical diagnostic tool in epileptic patients. PATIENT: A 22-year-old man with idiopathic epilepsy noticed a shadow in the central visual field of his right eye immediately following a Wada test of the right hemisphere. RESULTS: The patient presented with an occlusion of two small branch retinal arteries and corresponding defects in his visual field. Fluorescence angiography revealed small dense hyperfluorescent spots within the occluded retinal vessels. CONCLUSION: Branch retinal artery occlusions are a possible complication of the Wada test, possibly induced by undissolved contrast medium or sodium amytal.

Adult↗
PubMed2000

Inner-medullary organic osmolytes and inorganic electrolytes in K depletion.

The renal concentrating defect typical for chronic K depletion has been ascribed to malfunction of renomedullary cells caused by inadequate accumulation of organic osmolytes. A reduction in intracellular ionic strength, which is believed to influence decisively the accumulation of organic osmolytes, has been held responsible for insufficient osmolyte accumulation. To test this hypothesis, intra- and extracellular Na, Cl and K concentrations, the major determinants of ionic strength, were measured in the papilla by electron microprobe analysis and organic osmolytes (glycerophosphorylcholine, betaine, sorbitol, myo-inositol, free amino acids) in inner-medullary tissue by HPLC in antidiuretic rats kept on either a control (normal-K) or a K-deplete (low-K) diet and in euhydrated rats with free access to water and control diet. K depletion was associated with a reduced urine concentrating ability. Papillary interstitial ionic strength (sum of Na, Cl and K) in antidiuretic low-K rats was significantly reduced compared with antidiuretic normal-K rats (688+/-19 vs. 971+/-61 mmol/kg wet wt) but was similar to that in euhydrated normal-K rats (643+/-35 mmol/kg wet wt). The lower interstitial ionic strength in antidiuretic low-K and euhydrated normal-K rats was associated with a lower total content of organic osmolytes in the inner medulla (365+/-14 and 381+/-20, respectively, vs. 465+/-11 mmol/kg protein in antidiuretic normal-K rats). Intracellular ionic strength (sum of Na, Cl and K) of papillary collecting duct cells, however, was similar in antidiuretic normal-K and euhydrated normal-K rats (171+/-5 and 179+/-11 mmol/kg wet wt) but lower in antidiuretic low-K rats (138+/-9 mmol/kg wet wt). These results do not support the view that, in the steady state of osmotic adaptation of renomedullary cells in situ, intracellular ionic strength is the decisive factor for maintaining high levels of organic osmolytes. During chronic K depletion, reduced osmolyte accumulation by renomedullary cells may be the consequence, rather than the cause, of lower medullary interstitial tonicity.

Amino Acids↗
PubMed2000

Argatroban and alteplase in patients with acute myocardial infarction: the ARGAMI Study.

ARGAMI was designed to assess safety and efficacy of argatroban compared with heparin as adjunctive treatment to alteplase in the treatment of patients with acute myocardial infarction. ARGAMI consisted of an open-dose finding study (35 patients) followed by a placebo-controlled study with double dummy technique and 2:1 (argatroban:heparin) randomization. An argatroban dosage of 100 microg/kg bolus plus 3 microg/kg/min infusion for 72 hours was selected for the randomized study in which 82 patients were allocated to argatroban and 45 to heparin (5000 U intravenous bolus, 1000 U/h infusion). Patency of the infarct-related artery (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3 flow) after 90 minutes was obtained in 62 patients (76%) allocated to argatroban versus 37 patients (82%) allocated to heparin (p=ns). Angiograms after 24 hours and 5 to 10 days showed low reocclusion rates in both groups. Bleeding complications were observed in 16 patients allocated to argatroban (19.5%) and in 9 patients allocated to heparin (20.0%). One patient allocated to heparin suffered from hemorrhage stroke. Argatroban, given as adjunctive treatment to alteplase, is tolerated well in patients with acute myocardial infarction. Safety and efficacy of the combination alteplase and argatroban (with this dose regimen) are similar to those of alteplase and heparin.

Aged↗
PubMed2000

Specific fitness training and testing in competitive sports.

Improvements of athletic capacity in high-performance sport are mainly achieved through an increase of the quality of training. In physical preparation, the quality of training can be improved by developing highly specific means of training. The aim of this paper is to present three examples of how highly specific means of fitness training of world class athletes can be developed. The first example presents a test profile of specific motor abilities of top class tennis players, the second one deals with the improvement of specific strength training methods for ski jumpers, and the third deals with the development of specific training devices of Alpine ski racers.

Analysis of Variance↗
PubMed2000

Molecular chaperones in the kidney: distribution, putative roles, and regulation.

Molecular chaperones are intracellular proteins that prevent inappropriate intra- and intermolecular interactions of polypetide chains. A specific group of highly conserved molecular chaperones are the heat shock proteins (HSPs), many of which are constitutively expressed but most of which are inducible by diverse (in some cases specific) stress factors. HSPs, either alone or in cooperation with "partner" chaperones, are involved in cellular processes as disparate as correct folding and assembly of proteins, transport of proteins to specific intracellular locations, protein degradation, and preservation and restructuring of the cytoskeleton. The characteristic distribution of individual HSPs in the kidney, and their response to different challenges, suggests that a number of HSPs may fulfill specific, kidney-related functions. HSP72 and the osmotic stress protein 94 (Osp94) appear to participate in the adaptation of medullary cells to high extracellular salt and urea concentrations; the small HSPs (HSP25/27 and crystallins) may be involved in the function of mesangial cells and podocytes and contribute to the volume-regulatory remodeling of the cytoskeleton in medullary cells during changes in extracellular tonicity. HSP90 contributes critically to the maturation of steroid hormone receptors and may thus be a critical determinant of the aldosterone sensitivity of specific renal epithelial cells. Certain HSPs are also induced in various pathological states of the kidney. The observation that the expression of individual HSPs in specific kidney diseases often displays characteristic time courses and intrarenal distribution patterns supports the idea that HSPs are involved in the recovery but possibly also in the initiation and/or maintenance phases of these disturbances.

Animals↗
PubMed2000

Nasal continuous positive airway pressure: A method to avoid endotracheal reintubation in postoperative high-risk patients with severe nonhypercapnic oxygenation failure.

OBJECTIVES: To study whether nasal continuous positive airway pressure (nCPAP) improves pulmonary oxygen transfer and avoids reintubation in patients with severe nonhypercapnic oxygenation failure after major cardiac, vascular, or abdominal surgery. DESIGN: Prospective interventional study. SETTING: Surgical ICU of a university hospital. PATIENTS: Twenty consecutive patients after thoracic, abdominal, or combined thoracoabdominal operations, in whom pulmonary oxygen transfer deteriorated continuously following elective extubation after initial mechanical ventilation. Respiratory failure was due to atelectasis and/or left heart failure, and all patients met predefined criteria for reintubation. INTERVENTIONS: nCPAP therapy (8 to 10 cm H(2)O) was initiated if PaO(2) had decreased to < 80 mm Hg despite application of 100% oxygen (flow, 25 L/min), intermittent mask continuous positive airway pressure, and maximum conventional therapy. MEASUREMENTS AND RESULTS: nCPAP treatment was started 24.1 +/- 3.4 h after elective extubation. PaO(2) was < 80 mm Hg in all patients, in 13 patients it was < 60 mm Hg, and in 3 patients it was < 50 mm Hg. Mean PaO(2)/fraction of inspired oxygen (FIO(2)) ratio had decreased to 60 +/- 2.6, and increased within the first hour of nCPAP to 136 +/- 12 (p < 0.001). The clinical condition in all patients improved further, and after 35.2 +/- 6.3 h, all patients were well oxygenated by face mask at ambient pressure (PaO(2)/FIO(2) ratio, 146 +/- 14). Two patients were reintubated for reasons unrelated to oxygenation or ventilation (data are presented as mean +/- SEM). CONCLUSIONS: nCPAP is safe, easy to apply, and effective to improve arterial blood oxygenation in < 1 h in postoperative patients with severe nonhypercapnic oxygenation failure. In these patients, who otherwise would have been reintubated, nCPAP can avoid endotracheal reintubation and mechanical ventilation.

Blood Gas Analysis↗
PubMed2000

The basaloid squamous cell carcinoma of the nasopharynx.

The basaloid squamous cell carcinoma (BSCC) is a very rare and widely unknown malignant tumour of the upper aerodigestive tract. It is considered a particular variant of squamous cell carcinoma (SCC), but much more aggressive. A relatively little number of cases and clinical reports has been published since its first description in 1986 by Wain et al. Only five basaloid squamous cell carcinomas with location in the nasopharynx, where it seems to have a different biological behaviour, are mentioned in the international literature. We present a new case of BSCC with this location, referring to the pathologic and clinical aspects and to the respective literature.

Biopsy, Needle↗
PubMed1999

Biohybride nerve guide for regeneration: degradable polylactide fibers coated with rat Schwann cells.

The restricted capacity of the nervous system to regenerate calls for novel therapeutic concepts. We have tested biocompatible polylactide fibers as potential nerve guides that could bridge proximal nerve stumps and synaptic target regions after nerve lesion. Polylactides have the great advantage that they degrade and resorb after completion of regeneration. Material surface properties were optimized three-fold by oxygen plasma treatment, polyanion coating and the seeding of Schwann cells from rat sciatic nerve. Immunocytochemistry and scanning electron microscopy revealed that in vitro axonal outgrowth of dorsal root ganglia on two specifically synthesized lactide polymers can be greatly improved by these surface treatments. The approach aims to develop an 'intelligent neuroprosthesis' that in vivo facilitates directed axonal regrowth in the first place and disappears thereafter.

Animals↗
PubMed1999

Breeding soundness evaluation of extensively managed bulls in Costa Rica.

This paper describes the results of single breeding soundness evaluations (BSE) in 898 Bos indicus, Bos taurus and B. indicus x B. taurus bulls, 1 to 12 yr old, extensively reared in different climatic regions of Costa Rica and representing approximately 2% of the total breeding bull population. Thirty-three percent (n = 296) of the bulls were classified as unsound for breeding owing to clinical problems (9.1%, n = 82), low scrotal circumference (SC) being the most common finding, followed by unsatisfactory sperm morphology (23.9%, n = 214). The prevalence of bulls unsound for breeding was lowest in Bos indicus (29%, P < 0.01), intermediate in B. taurus (41%), and highest in B. indicus x B. taurus (48%). The percentages of abnormal sperm heads, acrosomes and midpieces tended to be higher in the ejaculates of bulls with softer testicular consistency (P < 0.001), a long scrotum (P < 0.01) or a low SC (P < 0.05), and such bulls were more often classified as being unsound for breeding (P < 0.05). Frequencies of sperm abnormalities were higher in bulls < 2 yr of age than in older males (P < 0.01) and were highest in B. indicus x B. taurus bulls (P < 0.001). The results confirm differences between species in their adaptability to a tropical environment and support earlier evidence of an association between SC, testicular consistency and scrotal length clinical parameters, and testicular function in bulls.

Animals↗
PubMed1999

[Interferon therapy of chronic viral hepatitis in Hungary: 5-year experience. A multicenter study].

In Hungary over the past 5 years more than thousand patients with chronic viral hepatitis have been examined and included in a treatment program with interferon (IFN) at 16 major hepatology centers, using unified diagnostic and therapeutical criteria. Authors give an account of their experiences on the clinical features of patients with chronic viral hepatitis and report the results of the treatment with IFN. According to the rules and availability of IFN for patients with chronic viral hepatitis in the country, virtually the entire Hungarian population with this diseases who required IFN therapy have been included. A total of 94 patients suffered from hepatitis B virus (HBV) infection, in addition 11 HBV + hepatitis Delta virus (HDV), 24 HBV + Hepatitis C virus (HCV) related liver disease, and 993 had chronic hepatitis C. IFN therapy for chronic HBV hepatitis consisted of IFN 5 MU thrice weekly for 6 months, and resulted in 33% seroconversion and sustained remission with 14% HBsAg clearance. For chronic hepatitis C treatment protocols (dose of IFN and duration of therapy) have changed with the time (from a weekly dose of 3 x 3 MU IFN for 6 months, to 3 x 3 MU for 12 months), and even a combination with ribavirin has been introduced. Although the therapeutic results showed a gradual improvement form a 13% sustained response over 22% in the first and second periods, respectively, differences were most significant with the advent of the combination therapy, that resulted in 36% remission rate. Only fibrosis in histology and baseline pretreatment HCV-RNA level appeared as predictors of response in chronic hepatitis C. Neither age nor gender did influence the outcome, but longer duration of treatment and higher total dose of IFN resulted moderately higher sustained remission rates. The experiences are in accordance with findings of suboptimal efficacy of IFN monotherapy reported worldwide and emphasize the need of seeking for newer and combination therapeutic modalities for these chronic viral diseases.

Adolescent↗
PubMed1999

Possible involvement of heat shock protein 25 in the angiotensin II-induced glomerular mesangial cell contraction via p38 MAP kinase.

In the rat kidney, mesangial cells (MCs), especially those in the extraglomerular mesangium (EGM) region of the juxtagomerular apparatus, express high amounts of heat shock protein 25 (HSP25). Because MCs are contractile in vivo and HSP25 is known to modulate polymerization/depolymerization of F-actin and to be involved in smooth muscle contraction, it is possible that HSP25 participates in the contraction process of MCs. We analyzed a permanent mouse MC line using Northern and Western blot analyses, and observed that similar to the MCs in the glomerulus, these cells also express high amounts of HSP25 constitutively. Exposure of these cells to angiotensin II (ANG II: 2 x 10(-7) M) evoked contraction and a concomitant increase in HSP25 phosphorylation, while the cytoplasmic fraction of HSP25 was transiently reduced. Because phosphorylation of HSP25 is essential for its actin-modulating function, we suppressed the activity of p38 MAP kinase, the major upstream activator of HSP25 phosphorylation, with the specific inhibitor SB 203580. This maneuver reduced HSP25 phosphorylation dramatically, abolished cell contraction, and prevented the decrease of the cytoplasmic HSP25 content. This suggests that HSP25 might be a component of the contraction machinery in MCs and that this process depends on p38 MAP kinase-mediated HSP25 phosphorylation. The decrease of cytoplasmic HSP25 content observed after ANG II exposure is probably the result of a transient redistribution of HSP25 into a buffer-insoluble fraction, because the whole cell content of HSP25 did not change, a phenomenon known to be related to the actin-modulating activity of HSP25. The fact that this function requires phosphorylation of HSP25 would explain the observation that HSP25 does not redistribute in SB 203580-pretreated cells.

Angiotensin II↗
PubMed1999

Fibroblast activation protein: a cell surface dipeptidyl peptidase and gelatinase expressed by stellate cells at the tissue remodelling interface in human cirrhosis.

Fibroblast activation protein (FAP) is a cell surface-bound protease of the prolyl oligopeptidase gene family expressed at sites of tissue remodelling. This study aimed to delineate the expression of FAP in cirrhotic human liver and examine its biochemical activities. Seventeen cirrhotic and 8 normal liver samples were examined by immunohistochemistry and reverse-transcriptase polymerase chain reaction (RT-PCR). Hepatic stellate cells (HSC) were isolated and immunostained. Recombinant FAP and immunopurified, natural FAP were analyzed for protease activities and similarities to dipeptidyl peptidase IV (DPPIV), a structurally related enzyme. FAP-specific messenger RNA and immunoreactivity were detected in cirrhotic, but not normal, livers. FAP immunoreactivity was most intense on perisinusoidal cells of the periseptal regions within regenerative nodules (15 of 15 cases); this pattern coincides with the tissue remodelling interface. In addition, human FAP was expressed by cells within the fibrous septa (10 of 15 cases). Cell morphology, location, and colocalization with glial fibrillary acidic protein (GFAP) indicated that FAP is present on HSC in vivo. Similarly, isolated HSC expressed FAP in vitro. Both natural FAP from cirrhotic liver and recombinant FAP were shown to have gelatinase and dipeptidyl peptidase activities. FAP is a cell-bound, dual-specificity dipeptidyl peptidase and gelatinase expressed by activated HSC at the tissue remodelling interface in human cirrhosis. FAP may contribute to the HSC-induced extracellular matrix (ECM) changes of cirrhosis.

Actins↗
PubMed1999

Glial cell swelling--effect of hypothermia.

The effect of mild to moderate hypothermia (32/27 degrees C) was analyzed on the cell volume of C6 glioma cells and primary cultured astrocytes at normal pH, during lactacidosis (pH6.2) and during exposure to glutamate or arachidonic acid in vitro. The cells were suspended in an incubation chamber under continuous control of pH, pO2 and temperature. Cell swelling was quantified by an advanced Coulter-system. Following a control period at 37 degrees C, the ambient temperature was decreased to 27 and 32 degrees C for 30 min. Hypothermia alone led to an immediate and significant cell volume increase of 107.3 +/- 0.4% (mean +/- SEM) of control after 30 min at 32 degrees C. Yet, hypothermia (27 degrees C) afforded partial protection against the acidosis-induced cell swelling at pH 6.2, attaining 120.4 +/- 0.9% in the normothermic control group after 60 min, while only 111.3 +/- 0.9% at 27 degrees C. Hypothermia, however, was not associated with a reduction of the glutamate- or arachidonic acid-induced cell swelling. The results demonstrate that mild hypothermia per se induces glial cell swelling, but simultaneously inhibits cell swelling from acidosis, while not from glutamate- or arachidonic acid.

Acidosis, Lactic↗