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M Bürger

Publications and source records attributed to M Bürger.

10 recordsLinked to original sources
PubMed2004

An integrated methodology to assess the benefits of urban green space.

The interrelated issues of urban sprawl, traffic congestion, noise, and air pollution are major socioeconomic problems faced by most European cities. A methodology is currently being developed for evaluating the role of green space and urban form in alleviating the adverse effects of urbanisation, mainly focusing on the environment but also accounting for socioeconomic aspects. The objectives and structure of the methodology are briefly outlined and illustrated with preliminary results obtained from case studies performed on several European cities.

Conservation of Natural Resources↗
PubMed1992

[The Shy-Drager syndrome].

For 15 years a now 70-year-old woman had been having occasional episodes of circulatory collapse which 7 years ago were diagnosed as being caused by severe idiopathic orthostatic hypotension. These episodes had recently become much more frequent and she was hardly able to be upright for more than one minute. In the Schellong test the blood pressure fell from 80/50 mm Hg when lying to 70/30 mm Hg on standing, the pulse rate remaining unchanged at 60/min. The standing test had to be abandoned after 90 seconds. Serum catecholamine concentrations (epinephrine 65 ng/l, norepinephrine 100 ng/l) did not rise on standing (epinephrine 25 ng/l, norepinephrine 105 ng/l). 24-hour urinary excretion of vanillyl mandelic acid was at the lower limit of normal (2.2 mg). The autonomic dysfunction of circulatory control suggested a Shy-Drager syndrome. Other signs of autonomic failure included gastroparesis, decreased tear and sweat secretion and transitory urinary incontinence. Symptomatic treatment with elastic stockings, fludrocortisone, etilefrine, dihydroergotamine, L-dopa, yohimbine and amezinium methylsulfate gave the patient greater mobility without achieving normal blood pressure responses.

Aged↗
PubMed1992

Energy expenditure and substrate oxidation in patients with cirrhosis: the impact of cause, clinical staging and nutritional state.

Many clinicians subjectively feel that cirrhotic patients frequently have clinical signs of hypermetabolism. However, it is unknown whether hypermetabolism is a constant feature of chronic liver disease, corresponds to liver destruction and repair or is of prognostic value. This article is about resting energy expenditure and substrate oxidation rates in 123 patients with biopsy-proven cirrhosis differing with respect to cause, duration of the disease, biochemical parameters of parenchymal cell damage, cholestasis, liver function, number of complications, clinical staging and nutritional state. Resting energy expenditure varied between 1,090 and 2,300 kcal/day and differed from the predicted values in 70% of the patients. Resting energy expenditure was closely related to fat-free mass, and 52% of the variability could be explained by fat-free mass, age and sex. Of all the patients, 18% were hypermetabolic and 31% were hypometabolic. Hypermetabolism showed no strict association with the cause of cirrhosis, the duration of the disease, liver function, cholestasis, cell damage, clinical staging, blood hemoglobin, plasma thyroid hormone levels or human leukocyte antigens. An increased resting energy expenditure was associated with significant losses of muscle, body cell mass and extracellular mass at unchanged body fat, whereas fat and fat-free mass were increased in hypometabolic patients when compared with normometabolic patients. Lipid oxidation was increased, but glucose oxidation was reduced in nearly all patients with cirrhosis. This was most pronounced at advanced stages of liver disease. Although similar with respect to liver function and clinical staging, 76.2% of hypermetabolic patients had transplants within the observation period, compared with only 16.7% and 8.1% in the normometabolic group and hypometabolic group, respectively. Posttransplantation mortality was independent of pretransplantation resting energy expenditure, but it increased significantly in patients with losses in body cell mass. In conclusion, hypermetabolism is not a constant feature of cirrhosis and results more from extrahepatic than from hepatic factors. It may cause malnutrition and contributes to the clinical outcome of patients with chronic liver disease.

Adult↗
PubMed1992

Protein-calorie malnutrition in liver cirrhosis.

The purpose of this article is to present detailed data on the nutritional assessment in cirrhotic patients. The exact frequency and types of malnutrition, its associations with the aetiology of liver disease, liver dysfunction and clinical staging in liver cirrhosis are unknown. A new classification system is presented which may help to suggest some interventional guidelines. Physical (anthropometry, 24-h urinary creatinine excretion, bioelectrical impedance analysis (BIA), total body potassium counting, ultrasound examination) and metabolic (indirect calorimetry) assessment of nutritional status was therefore performed in 123 patients with liver cirrhosis, who were considered as potential candidates for liver transplantation. Data were related to the clinical, biochemical, histological and prognostic data of liver disease. Of our patients 65% showed some signs of protein-calorie malnutrition as indicated by low body cell mass, reduced serum albumin concentrations or abnormal skinfold thickness. Of these 34% were considered as "kwashiorkor-like" (normal body composition, serum albumin less than 35 g/l), and 18% were "marastic" (reduced body weight, body cell mass, and fat mass). However, 49% of the malnourished group had reduced body cell mass in association with increased fat mass and frequently presented with a normal body weight ("mixed" or "obese" type). Protein-calorie malnutrition did not correlate with the aetiology of the disease and biochemical parameters of liver function. Malnutrition was observed at all clinical stages but was more frequently seen at advanced stages. We conclude that malnutrition associated with liver cirrhosis is not a clear phenomenon. Its clinical presentation is heterogenous and not reflected by the histological or biochemical parameters of liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mechanism of insulin resistance associated with liver cirrhosis.

Insulin-induced glucose metabolism was investigated in 26 patients with biopsy-proven liver cirrhosis and 10 control subjects. Two glucose clamp protocols together with continuous indirect calorimetry were performed to examine whether reduced rates of glucose oxidation and/or nonoxidative glucose metabolism explain insulin resistance in liver cirrhosis. Using a 4-hour, two-step protocol (0-2 hours, plasma glucose 5.2 mmol/L, plasma insulin 92 mU/L to test the half-maximum response; 2-4 hours, hyperglycemia 10.0 mmol/L, plasma insulin 442 mU/L to test the maximum cellular glucose disposal) liver cirrhosis reduced glucose disposal to 45% and 60% of control values, respectively. Simultaneously, insulin-induced increases in glucose oxidation, plasma lactate levels, and lipogenesis were normal, whereas nonoxidative glucose metabolism was reduced (-82% and -47% of controls, respectively). To determine whether reduced nonoxidative glucose metabolism was caused by reduced glucose disposal, glucose disposal was "matched" to normal values in a subgroup of cirrhotic patients. Nonoxidative glucose metabolism values were normal, but plasma lactate concentrations disproportionally increased (+96%) after "matching" glucose disposal. Insulin resistance was independent of the etiology of the cirrhosis, the biochemical parameters of parenchymal cell damage and liver function, and the clinical and nutritional state of the patients. It is concluded that liver cirrhosis impairs insulin sensitivity and maximum cellular glucose disposal. Reduced glucose disposal is caused by defective glucose storage. Insulin resistance is independent of the etiology of liver cirrhosis and of the clinical and nutritional state of the patient.

Adult↗
PubMed1981

Dependency on serine concentration of the activity of tryptophan synthase. Cooperative properties.

The activity of the enzyme tryptophan synthase from Escherichia coli was tested as a function of the concentration of L-serine which serves as a substrate in the indole to tryptophan reaction as well as for the L-serine deaminase activity. L-Serine binding was found to follow the pattern of negative cooperativity both by kinetic and by equilibrium methods. The enzyme kinetic data support the view that a rapid equilibration model for the enzyme . substrates complex formation is not strictly obeyed.

Escherichia coli↗