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G Müller

Publications and source records attributed to G Müller.

At least 37 records · Page 2Linked to original sources
PubMed2004

A new test to improve the training quality of wheelchair racing athletes.

STUDY DESIGN: Validation of a new wheelchair racing test. OBJECTIVE: To assess the reproducibility of test parameters at different, subjectively chosen, intensity levels in wheelchair racing athletes. SETTING: Swiss Paraplegic Centre, Nottwil, Switzerland. SUBJECTS: We tested 11 (eight male, three female) young competitive wheelchair racing athletes. Their age was 20.5+/-6.4 years, height 164.7+/-16.3 cm and weight 54.1+/-9.2 kg. Average weekly training time was 6.8+/-2.7 h. All had been engaged in regular training for over 3.9+/-2.8 years. METHODS: Within a period of 3+/-1 days, every athlete completed two identical tests in their own racing chair on a training roller. The tests consisted of five 1500 m bouts at routine training intensities of 1 (warm-up) up to 5 (race speed), with a rest of 2 min between each bout. The athletes were blinded to all the collected data during the whole of the test, except for indications of the 500, 1000 and 1500 m markers. We measured the overall time (for 1500 m), average speed, stroke frequency, heart rate, rate of perceived exertion (RPE) and the concentration of lactic acid for all five intensity bouts. In order to get a measure on how reproducible these intensity levels were, we compared the two tests of each athlete with each other, and calculated the root-mean-squared coefficients of variation (CV) for all measured parameters during every bout. RESULTS: CVs of the measured data show that the most reproducible values were found for bout 5 (2.6-7.9%); except for the lactic acid parameter. The heart rate (CV: 3.1-6.4%) and stroke frequency (CV: 6.5-7.9%) parameters reached rather constant values throughout all five bouts. Lactic acid concentrations showed very high CVs (16.8-29.7%). CONCLUSION: We conclude that this test is, with the exception of the lactic acid measurements, well reproducible, and particularly suitable for young wheelchair athletes. We find it to be a helpful tool for improving awareness for the individual training intensities, and for pursuing the development of the training process, as particularly the high-intensity bouts are well reproducible.

Adolescent↗
PubMed2004

Optimal exercise intensities for fat metabolism in handbike cycling and cycling.

STUDY DESIGN: Energy expenditure (EE) and fat oxidation in handbike cycling compared to cycling in order to determine the intensity that elicits maximal fat oxidation in handbike cycling. OBJECTIVE: To establish the exercise intensity with the highest fat oxidation rate in handbike cycling compared with cycling (control group) in order to give training recommendations for spinal cord-injured (SCI) athletes performing handbike cycling. SETTING: Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland. METHODS: Eight endurance-trained handbike cyclists (VO2 peak(handbike cycling) 37.5+/-7.8 ml/kg/min) and eight endurance trained cyclists (VO2 peak(cycling) 62.5+/-4.5 ml/kg/min) performed three 20-min exercise blocks at 55, 65 and 75% VO2 peak in handbike cycling on a treadmill or in cycling on a cycling ergometer, respectively, in order to find the intensity with the absolutely highest fat oxidation. RESULTS: The contribution of fat to total EE was highest (39.1+/-16.3% EE) at 55% VO2 peak in handbike cycling compared to cycling, where highest contribution of fat to EE (50.8+/-13.8%) was found at 75% VO2 peak. In handbike cycling, the highest absolute fat oxidation (0.28+/-0.10 g/min) was found at 55% VO2 peak compared to cycling, where highest fat oxidation (0.67+/-0.20 g/min) was found at 75% VO2 peak. CONCLUSION: Well-trained handbike cyclists have their highest fat oxidation at 55% VO2 peak(handbike cycling) compared to well-trained cyclists at 75% VO2 peak(cycling). Handbike cyclists should perform endurance exercise training at 55% VO2 peak(handbike cycling), whereas well-trained cyclists should be able to exercise at 75% VO2 peak(cycling). For training recommendations, the heart rate at 55% VO2 peak(handbike cycling) lies at 135+/-6 bpm in handbike cycling in SCI compared to 147+/-14 bpm at 75% VO2 peak(cycling) in well-trained cyclists. We presume that the reduced muscle mass involved in exercise during handbike cycling is the most important factor for impaired fat oxidation compared to cycling. But also other factors as fitness level and haemodynamic differences should be considered. Our results are only applicable to well-trained handbike cyclists with SCI and not for the general SCI population.

Adult↗
PubMed2004

Fat oxidation in men and women endurance athletes in running and cycling.

Recent studies showed that the maximal fat oxidation seems to be different in men and women and that it can be influenced by type and intensity of exercise. Nineteen endurance trained male (V.O (2)peak 61.3 +/- 4.4 ml x kg (-1) x min (-1)) and 17 female (V.O (2)peak 52.8 +/- 4.5 ml x kg (-1) x min (-1)) athletes were studied over 30 min at 55, 65 and 75 % V.O (2)peak on a treadmill and a cycling ergometer in order to find the intensity and kind of exercise with the highest absolute fat oxidation. For women, normalised (per body weight) fat oxidation was higher at 75 % V.O (2)peak than at 55 % V.O (2)peak for both running (p = 0.02) and cycling (p = 0.01). Women also oxidised a significantly higher percentage of fat with regard to total energy expenditure than men in running (p = 0.02) and cycling (p = 0.004). Normalised carbohydrate oxidation was significantly higher for men at each tested intensity (p < 0.05) and compared to kind of exercise in men (p = 0.006) and women (p = 0.002) in cycling than in running. Men and women showed a significantly higher normalised fat oxidation for running compared to cycling (p = 0.01). Cycling produced in men (p = 0.06) and women (p = 0.001) significantly more lactate than running. In summary, we found at 75 % V.O (2)peak a higher fat oxidation rate than at 65 % V.O (2)peak and 55 % V.O (2)peak for men and women in cycling and running. This is coincident with lactate threshold in men and women in cycling but not in running, where lactate threshold is higher than 75 % V.O (2)peak.

Adult↗
PubMed2004

Analysis of the RNA of Potato yellow vein virus: evidence for a tripartite genome and conserved 3'-terminal structures among members of the genus Crinivirus.

Double-stranded RNA preparations produced from potato plants graft-inoculated with a Peruvian isolate of Potato yellow vein virus (PYVV; genus Crinivirus, family Closteroviridae) contain five RNA species denoted RNA 1, RNA 2, RNA 3, x and y of approximately 8, 5.3, 3.8, 2.0 and 1.8 kbp, respectively. The complete nucleotide sequences of PYVV RNAs 1, 2 and 3 and Northern hybridization analysis showed that PYVV RNA 1 contained the replication module and an additional open reading frame (p7), while two distinct species, RNAs 2 and 3, contain the Closteroviridae hallmark gene array. Pairwise comparisons and phylogeny of genome-encoded proteins showed that PYVV shares significant homology with other criniviruses but is most closely related to the Trialeurodes vaporariorum-vectored Cucumber yellows virus. Secondary structure prediction of the 3'-untranslated regions of all three PYVV RNAs revealed four conserved stem-loop structures and a 3'-terminal pseudoknot structure, also predicted for all fully characterized members of the genus Crinivirus and some members of the genera Closterovirus and Ampelovirus.

3' Untranslated Regions↗
PubMed2004

In vivo and in vitro evidence for a hepatic modulation of the leptin signal in rats.

BACKGROUND: Leptin is primarily secreted by the adipose tissue. It binds not only to hypothalamic structures involved in energy regulation but also to many peripheral tissues including the liver. Leptin circulates in free and receptor-bound forms. Both components are differentially regulated under various pathophysiological conditions and serve different physiological functions. They are released from adipose tissue but previous data suggest an additional formation outside the fat compartment. Here we tested the contribution of the liver in binding and modulating leptin in the circulation. MATERIALS AND METHODS: In vivo experiments were performed with radioactive labelled leptin with and without pretreatment with unlabelled leptin in freely moving, chronic intravenously cannulated male rats. Livers were investigated by immunohistochemistry and in situ hybridization and immunoblotting was performed, followed by ex vivo liver perfusion studies with human recombinant leptin. RESULTS: In in vivo experiments radioactively labelled leptin (at low concentrations) is avidly bound to rat liver (greater than 80% of basal serum values 90 min following i.v. infusion). Pre-treatment with excess of unlabelled leptin in vivo revealed a rapid hepatic down-regulation of leptin receptor isoforms when tested by in situ hybridization, immunoblotting or immunohistochemistry. Ex vivo perfusion of rat liver with human recombinant leptin induced a dose- and time-dependent formation of receptor-bound leptin in the perfusate. CONCLUSIONS: The present data support an active role of the liver in the modulation of the leptin signal through different regulation of the soluble leptin receptor, the bound and free forms of the hormone, which may have important implications for leptin's central efficacy and the development of 'leptin resistance'.

Adipose Tissue↗
PubMed2004

Priming with testosterone enhances stimulated growth hormone secretion in boys with delayed puberty.

BACKGROUND AND OBJECTIVE: Tests for growth hormone (GH) deficiency are not always helpful in the differential diagnosis of physiological delay of growth and puberty and GH deficiency. PATIENTS AND METHODS: To enhance diagnostic specificity, we used a single dose testosterone priming before repeating the arginine stimulation test in 26 boys with short stature and only early signs of puberty who failed to show an adequate response of serum GH in the first test. RESULTS: 77% (20/26 patients) increased their serum GH peak to more than 10 ng/ml, whereas six patients were still below this concentration. CONCLUSION: We propose that testosterone priming is a useful tool to distinguish between physiological delay of growth and puberty and GH deficiency and should be included in the diagnostic procedure.

Adolescent↗
PubMed2004

Fluorides in groundwater, soil and infused black tea and the occurrence of dental fluorosis among school children of the Gaza strip.

The purpose of this study was to determine the fluoride levels in water, soil and tea, and to identify the major fluoride minerals in soil that supply water with fluoride ions. Another aim was to study the prevalence of dental fluorosis in permanent dentition of the school children of the Gaza Strip. Monitoring of fluoride levels in 73 groundwater wells and 20 topsoil samples for the last three years revealed a general trend of increasing from north to south of the Gaza Strip. A linear regression analysis found a correlation coefficient of r=0.93 between the fluoride concentrations in groundwater and soil for the same geographic areas. However, the X-ray diffraction technique (XRD) results showed that none of the four major fluoride minerals were detected in the tested soil samples; the PHREEQC model showed that fluorite (CaF2) was the main donating mineral of fluoride ions to groundwater. A high positive correlation was found between fluoride concentrations in groundwater and occurrence of dental fluorosis. Among 353 school children of the five geographic areas of the Gaza Strip the prevalence of dental fluorosis was 60%, and 40% had no signs of fluorosis in their permanent dentitions. The highest occurrence, 94%, was in Khan Yunis, followed by 82% in Rafah, 68% in the middle area, 29% in Gaza and the lowest occurrence of 9% was in the northern area. These percentages were directly proportional to the average content of fluoride in groundwater of each area: 2.6, 0.9, 1.7, 1.2, and 0.7 ppm, respectively. The exception was Rafah where people drank from new groundwater wells that have been dug in the last 10 years. The occurrence of the disease was due to intake of high amounts of fluorides in drinking water, tea and fish. Communication with population indicated a heavy intake of tea starting from a very young age; not uncommonly tea is put in nursing bottles. No significant correlation was found between prevalence figures and gender or age groups. This high prevalence indicates a need to examine other sources of F including diet.

Adolescent↗
PubMed2003

Molecular variation of Potato yellow vein virus isolates.

To evaluate the variation of Potato yellow vein virus from potato fields, 12 isolates were collected from Colombia and one was collected from Peru. Double-stranded RNA was extracted from the plants and used as a template for RT-PCR amplification of the coat protein ( CP) gene and, in separate reactions the C-terminal region of the heat shock protein 70 homologue ( Hsp70h) gene and the N-terminal region of the p60 open reading frame. The CP amplicons were subjected to single-strand conformation polymorphism (SSCP) analysis and, together with the other amplicon, nucleotide sequence analysis. These analyses suggested that there is low genetic diversity in the PYVV isolates examined and that the Peruvian isolate of PYVV may have originated in Colombia.

Capsid Proteins↗
PubMed2003

[Improvement of care for diabetics using the care model from Saxony].

BACKGROUND AND OBJECTIVE: By promoting the networking of all those involved in caring for diabetics in Saxony, through agreement between those who provide help to them and the organizations which pay the costs, the intention is to improve the overall quality of care of diabetics. It was the aim of this study to evaluate the effectiveness of this integrated health model. PATIENTS AND METHODS: As part of the 3rd Diabetes Agreement in Saxony, a total of 275,804 diabetics were registered, treated and their management costed in the first quarter of 2000 and the fourth quarter of 2001 (56.3% females, 43.7% males; median age 68,7 years). They were patients of 2800 general practitioners and 88 specialist practices. RESULTS: Nearly 80% of all diabetics were included. Taking the level of HbA1c as the criterion of quality achieved, it had decreased from 7,1 +/- 1,3 % in the first 3 months of 2000 to 6,8 +/- 1,3 % in the last 3 months of 2001, and regional differences had been reduced. There was an obvious correlation between early referral to specialist practices and good treatment results, as measured by HbA1c and blood pressure levels. While in 1996 patients were referred when the HbA1c level was 8.8% (median 8.5%), referrals in the last quarter of 2001 were made when the mean was 8,0% (median 7.7%). After two years the risk of inadequate treatment (HbA1c > 7.5% and blood pressure > 140/90 mmHg) had been clearly reduced in about half the cases. CONCLUSIONS: Diabetes agreements, as promulgated in Saxony, have provided effective disease management programs (DMP) for efficacious and efficient integrated diabetic care, so that with continuing effectiveness and further development the St. Vincent targets can be reached. Successful regional diabetes agreements must therefore be maintained within the new, politically centralized, DMPs.

Aged↗
PubMed2003

[Differential diagnosis of acute appendicitis and ileus. Invagination due to polypoid heterotopic gastric mucosa in the ileum without Meckel diverticulum].

A 13-year-old female presented with recurrent, right-sided abdominal pain since the age of 2 years. Examination showed a tender, cylindric mass in the right lower quadrant. Ultrasound and MRI revealed an ileocolic intussusception. On laparotomy, there was an ileo-ileal intussusception due to a 3.8-cm polypoid tumor about 40 cm proximal to the ileocoecal valve. Histology showed polypoid heterotopic gastric mucosa with no Meckel's diverticulum. To our knowledge, only 12 cases of intussusception of heterotopic gastric mucosa in the ileum without Meckel's diverticulum have been reported in literature. This case adds to this small list and represents a possible cause of intussusception.

Abdomen, Acute↗
PubMed2003

Influences of naturally occurring and experimentally induced porcine pneumonia on blood parameters.

It had been the objective of the studies described to establish local and systemic changes by naturally occurring pneumonia or pneumonia experimentally induced by Pasteurella multocida and Haemophilus parasuis in swine. Acute and chronic pneumonia was found to alter the cytokine level of lung lavage fluid and affect the composition and function of blood cells, especially with regard to phagocytosis, radical formation and cell surface receptors. Interleukin-6 levels in blood plasma rose 24h after experimental intrabronchial infection. The influences of the changes on growth and meat quality are discussed.

Acute Disease↗
PubMed2003

Effects of the mycotoxin ochratoxin A and some of its metabolites on human kidney cell lines.

The modulations of complement-regulating surface proteins on a human embryonic and a renal carcinoma cell line are described regarding the effects of ochratoxin A and some of its metabolites on the surface markers CD46, CD55 and CD59. Membrane integrity, cell proliferation and metabolic activity were reduced to different extents, depending on the kind of mycotoxin and the dosage, which was ranging from 10 to 1000 ng/ml. The number of cells carrying surface markers was suppressed significantly at 1000 ng/ml, in some cases even at 100 ng/ml, whereas the intensity of receptor expression on the positive cells was found to be stimulated. The fraction RE2 (OTC) isolated from an OTA-containing crude toxin surpassed the effects of all other ochratoxin metabolites. Apart from well-known cytotoxic and genotoxic effects modulation of cell surface marker expression by low concentrations of OTA and OTC deserves more attention with regard to its immuno-pathogenic importance. Furthermore, occurrence and impact of the mycotoxin OTC should be studied more into detail.

Antigens, CD↗
PubMed2003

Obesity and blood pressure--results from the examination of 2365 schoolchildren in Germany.

OBJECTIVES: To investigate the relationship between different indices of body fat and blood pressure in children and adolescents. DESIGN: Cross-sectional cohort study along with regular public health service examinations in school classes two, five and nine. PARTICIPANTS: A total of 2365 healthy schoolchildren aged 8-16 y. MEASUREMENTS: Body mass index (BMI), skinfolds, waist-hip ratio, body fat determined by bioelectric impedance analysis and blood pressure. RESULTS: In comparison with recently published normative data, a significant increase of obesity was found. There is a higher prevalence of obesity in children with lower education. A positive association between body fat and hypertension was observed in children aged above 10 y. The BMI had the strongest association with blood pressure among the indices of body fat considered here. CONCLUSION: Obesity is an increasing problem even among schoolchildren. This observation should be treated seriously as the relationship of body fat to cardiovascular risk is detectable already at a young age. Attention should be paid to the dependence of obesity on the level of education. The analysis suggests that BMI should be the preferred index to assess body fat. International Journal of Obesity (2003) 27, 1459-1464. doi:10.1038/sj.ijo.0802462

Adipose Tissue↗
PubMed2003

Evaluation of sprint exercise testing protocols in wheelchair athletes.

STUDY DESIGN: Comparison of five different exercise testing protocols with different speeds on a treadmill with seven wheelchair athletes. OBJECTIVE: To determine which speed and duration in an exercise protocol is best to test wheelchair athletes performing sprint races on a track. SETTING: Swiss Paraplegic Centre, Nottwil, Switzerland. METHODS: Three elite and four junior wheelchair athletes (18.7+/-6.8 years, 52.1+/-9.7 kg and 165.3+/-19.3 cm) performed five different exercise testing protocols at different speeds on a treadmill until exhaustion. Maximal effort treadmill (0.7% incline) testing protocols were performed using three timeframes. The first was focussing on short duration tests (S1 and S2) where incremental increases in velocity (0.42 and 0.1 m.s(-1)) were required from a stationary start. The second were medium duration tests (M1 and M2) where the athlete started at their 200 m and 800 m personal best time (mean velocities) and then had the velocity increased 1 km.h(-1) by every 10 and 60 s respectively. The long duration test (L) started at 14 km.h(-1) and velocity was increased by 2 km.h(-1) every 120 s. Maximal heart rate, maximal concentration of lactate, maximal speed, and maximal duration of the test were measured. RESULTS: The highest concentration of lactate and the highest heart rates were measured in the longest tests. CONCLUSION: During maximal effort testing wheelchair athletes are able to produce higher lactate concentrations when tested for longer duration. Post test lactate assessments provide little information in short duration testing protocols. Sequential lactate assessments post-test may provide additional information on the rate of recovery for middle distance wheelchair athletes and warrants further investigation.

Adolescent↗
PubMed2003

Antibacterial activity and endotoxin-binding capacity of Actisorb Silver 220.

Actisorb Silver 220 wound dressing demonstrated a high in vitro endotoxin-binding capacity combined with a marked bactericidal activity without releasing Pseudomonas aeruginosa endotoxins into the environment, and so may be beneficial in the treatment of infected wounds, particularly colonization by Gram-negative bacteria.

Anti-Infective Agents, Local↗
PubMed2003

Direct comparison of inositol phosphoglycan with prostaglandylinositol cyclic phosphate, two potential mediators of insulin action.

Though insulin signalling is thought by many groups to function without second messenger action, others have provided evidence for the existence and action of such regulators. Chemically quite different compounds, however, have been proposed as mediators, such as various inositol phosphoglycans and prostaglandylinositol cyclic phosphate (cyclic PIP). In spite of marked structural differences, these compounds are reported to have the same regulatory properties, i.e. to activate protein ser/thr phosphatases and to inhibit protein kinase A. In order to clarify this discrepancy, the regulatory potency of these different compounds was assayed under identical conditions. It was found that in contrast to cyclic PIP, the synthetic inositol phosphoglycan PIG41 neither directly inhibited protein kinase A nor activated protein ser/thr phosphatases. However, when added to intact cells, such as primary adipocytes, PIG41 inhibited isoproterenol-stimulated lipolysis. This effect most likely results from tyrosine phosphorylation of insulin receptor substrates (IRSs) by PIG41. This tyrosine phosphorylation is not carried out by the insulin receptor tyrosine kinase but by cytosolic tyrosine kinases. This indicates that cyclic PIP, an intracellular regulator, which primarily acts on protein kinase A and on protein ser/thr phosphatases, operates more downstream in the signal transduction cascade as compared to the inositol phosphoglycan PIG41. Thus, cyclic PIP appears to be a suitable candidate to close the gap between IRSs and the protein kinases/phosphatases involved in the signal transduction of insulin.

Adenosine Triphosphate↗