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Biomedical subjects

D Müller

Publications and source records attributed to D Müller.

At least 271 records · Page 15Linked to original sources
PubMed1990

Neuropsychological findings in treated Wilson's disease.

Seventeen patients, treated for Wilson's disease (WD), underwent a set of neuropsychological tests and were compared with a closely matched control group. There were clear differences between the groups (chi 2-test, p less than 0.0001). Wilson patients with only hepatic involvement, however, did not at all differ from their controls. Wilson patients with neuropsychiatric signs differed from controls on a reasoning test (p = 0.0016), and the entire WD group differed on a perceptual speed task (p = 0.0025). Compared to normal test values, however, the patients' group means were all within plus or minus one standard deviation from the normal mean. Special testing procedures and construction of the test battery excluded a factor of motor deficits as a major cause for the differences. The neuropsychological findings are viewed in relation to other findings in patients with motor disorders and predominantly subcortical lesion sites. Wilson's disease may be a dementing condition, but not when treated adequately.

Adolescent↗
PubMed1990

The synthesis of glycosaminoglycans in isolated hepatocytes during experimental liver fibrogenesis.

During human and experimental liver fibrogenesis, the pattern of glycosaminoglycans in fibrotic liver matrix is greatly changed by severalfold increases of hyaluronic acid, chondroitin sulfate, and dermatan sulfate, respectively. The present study aimed to determine whether hepatocytes take part during fibrogenesis in the alteration of the glycosaminoglycan profile in liver matrix. Rats received thioacetamide orally for 2 and 10 weeks, respectively. After 10 weeks a typical micronodular cirrhosis had developed. Hepatocytes isolated at these time points were characterized by light and electron microscopy and incubated for up to 4 h in suspension cultures in [35S]-sulfate and [3H]-glucosamine containing medium to study the synthesis and intra-/extracellular distribution of total and specific types of glycosaminoglycans. A biphasic change of glycosaminoglycan synthesis in hepatocytes was found. After 2 weeks of TAA-treatment parenchymal cells synthesized about 25% more labeled glycosaminoglycans than control liver cells, but at 10 weeks the synthesis was reduced by more than 40%. Thus, between 2 and 10 weeks of TAA-treatment hepatocellular glycosaminoglycan synthesis decreased by more than 50%. The major portion of newly synthesized glycosaminoglycans was nitrous acid labile and, hence, identified as heparan sulfate. Its fractional synthesis decreased from 0.90 in control cells to 0.84 (2 weeks TAA) and 0.76 (10 weeks TAA), respectively. Thus, the absolute synthesis of heparan sulfate was reduced by 50% in hepatocytes from cirrhosis liver. Eighty to 90% of labeled glycosaminoglycans remained cell-associated. Hyaluronic acid was detected neither in normal hepatocytes nor in hepatocytes from injured liver. We conclude from these data that parenchymal liver cells will not contribute actively to the accumulation of galactosaminoglycans (chondroitin sulfate, dermatan sulfate) and hyaluronic acid in the extracellular matrix during fibrogenesis. The diminished rate of synthesis of heparan sulfate in hepatocytes from cirrhotic liver might explain its fractional decrease in cirrhotic liver matrix.

Animals↗
PubMed1990

Role of small calibre chest tube drainage for iatrogenic pneumothorax.

A 2 mm Teflon catheter was used as a chest tube in 28 patients with iatrogenic pneumothorax. Frequent aspirations through the catheter were performed in 16 of the patients. In the remaining 12 patients the catheter was connected to a one way flutter valve. The treatment was successful in 27 of the 28 patients--one patient required a large calibre chest tube. The mean drainage time was 48 hours. The small catheter technique is superior to the use of a large intercostal drain as it is much less traumatic and troublesome. The small calibre chest tube with a one way valve is recommended as a safe and easy technique.

Adult↗
PubMed1990

A mechanism of haloalkene-induced renal carcinogenesis.

Several halogenated alkenes are nephrotoxic; some others induce renal tubular adenocarcinomas in rodents after lifelong administration. A bioactivation mechanism accounting for the organ-selective tumor induction has been elucidated: conjugation of the parent compounds with glutathione (GSH), catalyzed by hepatic GSH S-transferases, results in the formation of haloalkyl and halovinyl glutathione S-conjugates. Formation of S-conjugates (identified by NMR and mass spectrometry) could be demonstrated with trichloroethene, tetrachloroethene, hexachlorobutadiene, perfluoropropene, trichlorotrifluoropropene, and dichloroacetylene in incubations with rat liver microsomes and in the isolated perfused rat liver. The GSH conjugates formed are eliminated from the rat liver with the bile and may be translocated to the kidney, intact or after metabolism to the corresponding cysteine S-conjugates that are metabolized in the kidney by renal tubular cysteine conjugate beta-lyase (beta-lyase) to reactive intermediates, most likely thioacylchlorides and thioketenes. Interaction of these potent electrophiles with DNA [demonstrated for intermediates formed from S-(1,2,3,4,4-pentachlorobutadienyl)-L-cysteine] causes mutagenicity in bacteria, genotoxicity in cultured renal cells, and cytotoxicity in kidney cells. As an alternative to beta-lyase-catalyzed cleavage, the cysteine S-conjugates may be acetylated to the corresponding mercapturic acids, which have been identified in urine. The ability of the kidney to concentrate GSH and cysteine S-conjugates and the intensive metabolism of GSH S-conjugates to cysteine S-conjugates in this organ are evidently responsible for the organotropic carcinogenicity.

Acetylcysteine↗
PubMed1990

[F-waves and H-reflexes in hemispastic syndrome].

Canalized F-waves and H-reflexes occurring on small hand and foot muscles are to be considered symptoms of central disinhibition. Occurrence of these waves and reflexes in patients with hemispastic syndrome is analyzed and correlated with clinical aspects.

Adolescent↗
PubMed1990

Influence of acute physical exercise on glutathione and lipid peroxides in blood of rat and man.

In rats physical exercise (30 min running on a treadmill) lowered total glutathione, oxidized glutathione and lipid peroxide concentration in blood. In man (young healthy male volunteers, moderate to excellent physical condition) running (30 min) did not influence these parameters. It is concluded that by normal life and psychophysical vigilance the moderate oxidative stress could be compensated.

Adult↗
PubMed1990

[Infection model for the reproduction of eperythrozoonosis in splenectomized SPF primary piglets].

Reported in this paper is an infection experiment in which whole blood infected with Eperythrozoon (Ep.) suis was applied to bacterioscopically Ep. suis negative SPF primary piglets for the purpose of doubtless diagnosis of eperythrozoonosis (EEZ) of swine. EEZ could thus be clinically, bacterioscopically, haematologically, biochemically, pathologico-anatomically, and histologically reproduced. Such experimental infection, on top of splenectomy of EEZ-suspicious store pigs, was found to be an additional step for adequate diagnosis on the basis of animal experiments. Immediate and reliable diagnosis of EEZ was found to be generally possible solely by clinical, bacterioscopic, and haematological examinations.

Animals↗
PubMed1989

Isolation and characterization of parenchymal cells from experimentally induced macronodular rat liver cirrhosis.

Hepatocytes were isolated from thioacetamide (TAA)-induced macronodular cirrhotic rat livers by a collagenase perfusion method. In the content of cellular metabolites, fatty acid uptake and lipid secretion there were no substantial differences compared with cells isolated from micronodular cirrhosis described previously. In contrast to isolated hepatocytes from normal livers those from macronodular cirrhosis had a lowered cellular content of triglycerides, phospholipids and cholesterol but not of cholesterol esters and free fatty acids. In macronodular cirrhosis hepatocytes of hypertrophic type, rich in cell organelles, can be distinguished ultrastructurally from those with signs of atrophy and degeneration. Immediately after isolation many hepatocytes isolated from macronodular cirrhosis showed plasma membrane blebbing. Whereas the blebbing was without recognizable effects on the fine structure of the isolated hepatocytes of the hypertrophic type, in the more atrophic ones some mitochondria were swollen. In addition, morphological analysis of the crude and purified suspensions revealed a partial selection of the hypertrophic cells during the isolation procedure, presumably due to a more labile state of those cells which showed signs of atrophy and degeneration. When stabilized in the suspension medium, however, the hepatocytes maintained complex metabolic functions for at least 2 h. Thus, the method described allows the isolation of parenchymal cells from TAA-induced macronodular cirrhotic livers for studying ultrastructural and biochemical alterations in hyperregenerative experimental liver cirrhosis.

Animals↗
PubMed1989

Testing of hydralazine in in vivo-in vitro hepatocyte assays for UDS and stimulation of replicative DNA synthesis.

The vasodilator hydralazine was tested for induction of DNA-repair synthesis and stimulation of replicative DNA synthesis in rat hepatocytes after administration in vivo, either once or repetitively. No increase in unscheduled or replicative DNA synthesis was observed. By contrast, positive controls clearly induced DNA-repair synthesis, either after a single treatment (4-aminobiphenyl, dimethylnitrosamine and methyl methanesulphonate) or after repetitive treatment (benzo[a]pyrene), or stimulated replicative DNA synthesis (carbon tetrachloride and dimethylnitrosamine). Thus, hydralazine displayed no genotoxic and no tumour-promoting activity in these in vivo-in vitro test systems.

Animals↗
PubMed1989

Metabolic differences between AGA-and SGA-infants of very low birthweight. III. Influence of postnatal age.

Seven very low birthweight (VLBW) infants, small for gestational age (SGA), with moderate intrauterine growth retardation and 7 VLBW-infants, appropriate for gestational age (AGA), fed breast milk fortified with 6 g freeze-dried human milk per 100 ml were studied on the 8th, 21st and 42nd days of life. The protein intake on the study days varied between 2.68 and 3.61 g/kg/day in the SGA-and 2.69 and 3.75 g/kg/day in the AGA-infants. Serum concentrations of total bile acids (BA) and the renal excretion of total nitrogen (TN) as well as alpha-amino-nitrogen (AAN) were measured in all infants on each study day. On the 8th day of life a mean protein intake of 3.2 g/kg/day resulted in higher serum concentrations of BA as well as in a higher renal excretion of TN and AAN in the SGA-infants when compared to the AGA-infants. On the 21st day of life these differences were smaller and only the serum concentration of BA and the renal excretion of AAN were still significantly higher in the SGA-infants. On the 42nd day of life only serum concentrations of total BA were elevated in the SGA-infants when compared to that in the AGA-infants. The observed metabolic differences between moderately SGA-and AGA-infants related to protein and bile acid metabolism diminished during the first weeks of life. The present data suggest that when nutritional management of VLBW-infants is planned, differences in metabolic capacities must be considered and protein intake should be increased with caution and in accordance to the individual metabolic situation of the infants during the first weeks of life.

Age Factors↗
PubMed1989

[Neurophysiological research on the trigeminal nerve].

With neurophysiologic investigations we can distinguish many aspects of functional lesions in the nervus trigeminus, for example localization, prognosis and effects of treatment. Interdisciplinary cooperation is necessary.

Cranial Nerve Diseases↗
PubMed1989

[Determination of fucokinase activity in the blood of schizophrenic patients].

An investigation was conducted into whether dopamine induces an alteration in the fucolysation of glycoproteins, starting from the dopamine hypothesis of schizophrenia and taking the fucokinase activity determined in erythrocytes of schizophrenic patients as parameter. As with patients with "schizoaffective psychosis" and those with manic-depressive disorders, who were likewise examined, it was found that the enzyme activity of schizophrenic patients was no different than that found in the blood of a control group.

Adolescent↗