Short incubation with 2-methoxyestradiol kills malignant glioma cells independent of death receptor 5 upregulation.

We investigated the effects of 2-methoxyestradiol (2-ME), a promising new antitumor agent, on viable cell number and nuclear morphology of malignant glioma cells (three human and one rat glioma cell lines) and analyzed the controversial role of death recepor 5 (DR5) upregulation in 2-ME induced apoptosis. Microtiter-tetrazolium (MTT) assays showed a significant reduction of viable cells after incubation with 2 microM and 20 microM 2-ME for 48 and 72 hours in all cultures. In the 20 microM concentration, there were even significant effects in the majority of shorter incubation periods. Hoechst 33258 stains showed a substantial amount of cells with nuclear fragmentation indicating a late stage of apoptosis after 20 microM 2-ME treatments of 24 hours and more. The role of the DR5-mediated extrinsic apoptotic pathway was further studied in the three human glioma cell lines; 50 ng/ml of the DR5 ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) and 2 microM 2-ME showed no synergism, as determined by MTT assays. Real-time PCR revealed no significantly increased amount of DR5 mRNA, suggesting that receptor upregulation does not play a major role for 2-ME-induced apoptosis in glioma cells, in contrast to data for a breast cancer cell line in the literature.

Re-evaluation of the dysfunction of mitochondrial respiratory chain in skeletal muscle of patients with Parkinson's disease.

The origin and tissue distribution of the mitochondrial dysfunction in Parkinson's disease (PD) remains still a matter of controversy. To re-evaluate a probably free radical-born, generalized mitochondrial impairment in PD, we applied optimized enzymatic assays, high resolution oxygraphic measurements of permeabilized muscle fibers, and application of metabolic control analysis to skeletal muscle samples of 19 PD patients and 36 age-matched controls. We detected decreased activities of respiratory chain complexes I and IV being accompanied by increased flux control coefficients of complexes I and IV on oxygen consumption of muscle fibers. We further investigated if randomly distributed point mutations in two discrete regions of the mitochondrial DNA are increased in PD muscle, and if they could contribute to the mitochondrial impairment. Our data confirm the previously debated presence of a mild mitochondrial defect in skeletal muscle of patients with PD which is accompanied with an about 1.5 to 2-fold increase of point mutated mtDNA.

New insights into the metabolic consequences of large-scale mtDNA deletions: a quantitative analysis of biochemical, morphological, and genetic findings in human skeletal muscle.

In order to study putative genotype phenotype correlations in mitochondrial disorders due to large-scale mtDNA deletions we performed a quantitative analysis of biochemical, morphological, and genetic findings in 20 patients. The size of the mtDNA deletions varied from 2 to 7.5 kb with a degree of heteroplasmy ranging from 16% to 78%. Applying improved methods for measuring respiratory chain enzyme activities, we found highly significant inverse correlations between the percentage of cytochrome c oxidase (COX)- negative fibers and citrate synthase (CS) normalized COX ratios. Significant correlations were also established between CS normalized complex I and complex IV ratios as well as between the degree of heteroplasmy of mtDNA deletions and the percentage of ragged red fibers, COX-negative fibers, and CS normalized complex I and complex IV ratios. Our results indicate that the degree of heteroplasmy of mtDNA deletions is mirrored on the histological as well as the biochemical level. Furthermore, our findings suggest that single large-scale deletions equally influence the activities of all mitochondrially encoded respiratory chain enzymes. Even low degrees of heteroplasmy of mtDNA deletions were found to result in biochemical abnormalities indicating the absence of any well-defined mtDNA deletion threshold in skeletal muscle.

Mitochondrial DNA abnormalities in skeletal muscle of patients with sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is a neurodegenerative disease affecting the anterior horn cells of the spinal cord and cortical motor neurons. Previous findings have suggested a specific impairment of mitochondrial function in skeletal muscle of at least a limited number of patients. Applying flavoprotein/NAD(P)H autofluorescence imaging of mitochondrial function in saponin-permeabilized muscle fibres, we detected a heterogeneous distribution of the respiratory chain defect among individual fibres in muscle biopsies of patients (11 out of 17) with sporadic amyotrophic lateral sclerosis (SALS). These findings correlate with the presence of cytochrome c oxidase (COX)-negative muscle fibres detected histologically. We established the molecular basis for the decreased activities of NADH:CoQ oxidoreductase and COX in SALS muscle. In the skeletal muscle of the investigated patients, diminished levels (13 out of 17) or multiple deletions (one out of 17) of mitochondrial DNA (mtDNA) were observed. These alterations of mtDNA seem to be related to decreased levels of membrane-associated mitochondrial Mn-superoxide dismutase. Our results support the viewpoint that an oxygen radical-induced impairment of mtDNA is of pathophysiological significance in the aetiology of at least a subgroup of patients with SALS.

Evaluation of methods for the determination of mitochondrial respiratory chain enzyme activities in human skeletal muscle samples.

The quantification of mitochondrial enzyme activities in skeletal muscle samples of patients suspected of having mitochondrial myopathies is problematic. Therefore, we have evaluated different methods for the determination of activities cytochrome c oxidase and NADH:CoQ oxidoreductase in human skeletal muscle samples. The measurement of cytochrome c oxidase activity in the presence of 200 microM ferrocytochrome c and the detection of NADH:CoQ oxidoreductase as rotenone-sensitive NADH:CoQ(1) reductase resulted in comparable citrate synthase-normalized respiratory chain enzyme activities of both isolated mitochondria and homogenates from control human skeletal muscle samples. These methods allowed the precise detection of deficiencies of respiratory chain enzymes in skeletal muscle of two patients harboring only 20 and 27% of deleted mitochondrial DNA, respectively. Therefore, citrate synthase-normalized respiratory chain activities can serve as stable reference values for the determination of a putative mitochondrial defect in human skeletal muscle.

Permeabilized cell and skinned fiber techniques in studies of mitochondrial function in vivo.

In this chapter we describe in details the permeabilized cell and skinned fiber techniques and their applications for studies of mitochondrial function in vivo. The experience of more than 10 years of research in four countries is summarized. The use of saponin in very low concentration (50-100 microg/ml) for permeabilisation of the sarcolemma leaves all intracellular structures, including mitochondria, completely intact. The intactness of mitochondrial function in these skinned muscle fibers is demonstrated in this work by multiple methods, such as NADH and flavoprotein fluorescence studies, fluorescence imaging, confocal immunofluorescence microscopy and respiratory analysis. Permeabilized cell and skinned fiber techniques have several very significant advantages for studies of mitochondrial function, in comparison with the traditional methods of use of isolated mitochondria: (1) very small tissue samples are required; (2) all cellular population of mitochondria can be investigated; (3) most important, however, is that mitochondria are studied in their natural surrounding. The results of research by using this method show the existence of several new phenomenon--tissue dependence of the mechanism of regulation of mitochondrial respiration, and activation of respiration by selective proteolysis. These phenomena are explained by interaction of mitochondria with other cellular structures in vivo. The details of experimental studies with use of these techniques and problems of kinetic analysis of the results are discussed. Examples of large-scale clinical application of these methods are given.

Impaired mitochondrial oxidative phosphorylation in skeletal muscle of the dystrophin-deficient mdx mouse.

The mdx mouse, an animal model of the Duchenne muscular dystrophy, was used for the investigation of changes in mitochondrial function associated with dystrophin deficiency. Enzymatic analysis of skeletal muscle showed an approximately 50% decrease in the activity of all respiratory chain-linked enzymes in musculus quadriceps of adult mdx mice as compared with controls, while in cardiac muscle no difference was observed. The activities of cytosolic and mitochondrial matrix enzymes were not significantly different from the control values in both cardiac and skeletal muscles. In saponin-permeabilized skeletal muscle fibers of mdx mice the maximal rates of mitochondrial respiration were about two times lower than those of controls. These changes were also demonstrated on the level of isolated mitochondria. Mdx muscle mitochondria had only 60% of maximal respiration activities of control mice skeletal muscle mitochondria and contained only about 60% of hemoproteins of mitochondrial inner membrane. Similar findings were observed in a skeletal muscle biopsy of a Duchenne muscular dystrophy patient. These data strongly suggest that a specific decrease in the amount of all mitochondrial inner membrane enzymes, most probably as result of Ca2+ overload of muscle fibers, is the reason for the bioenergetic deficits in dystrophin-deficient skeletal muscle.

Impairment of mitochondrial function in skeletal muscle of patients with amyotrophic lateral sclerosis.

In skeletal muscle homogenates of 14 patients with sporadic amyotrophic lateral sclerosis, an approximately twofold lower specific activity of NADH:CoQ oxidoreductase in comparison to an age matched control group (n=28) was detected. This finding was confirmed by a detailed analysis of mitochondrial oxidative phosphorylation in skeletal muscle using saponin-permeabilized muscle fibers. (i) A significantly lowered maximal glutamate+malate and pyruvate+malate supported respiration of saponin-permeabilized fibers was detected in the patients group. (ii) Titrations with the specific inhibitor of NADH:CoQ oxidoreductase amytal revealed a higher sensitivity of respiration to this inhibitor indicating an elevated flux control coefficient of this enzyme. (iii) Applying functional imaging of mitochondria using ratios of NAD(P)H and flavoprotein autofluorescence images of saponin-permeabilized fibers we detected the presence of partially respiratory chain inhibited mitochondria on the single fiber level. A secondary defect of mitochondrial function due to the neurogenic changes in muscle seems to be unlikely since no mitochondrial abnormalities were detectable in biopsies of patients with spinal muscular atrophy. These results support the viewpoint that an impairment of mitochondria may be of pathophysiological significance in the etiology of amyotrophic lateral sclerosis.

Oxygen dependence of flux control of cytochrome c oxidase -- implications for mitochondrial diseases.

The oxygen dependence of cytochrome c oxidase control on succinate oxidation was investigated in saponin-permeabilized muscle fibers and isolated mitochondria from mouse quadriceps muscle applying metabolic control analysis. For this cyanide titrations of the oxygen consumption in the presence of succinate+rotenone were performed at different oxygen concentrations in the medium. While with isolated mitochondria high flux control coefficients were detected only at oxygen concentrations close to the KM value of cytochrome c oxidase, with saponin-permeabilized fibers a significant increase of cytochrome c oxidase flux control was already observed below 130 microM oxygen. The result is in line with the high oxygen sensitivity of maximal respiration of saponin-permeabilized muscle fibers (P50 = 33 microM) caused most probably by oxygen diffusion gradients through the fiber lattice. The oxygen dependence of cytochrome c oxidase flux control in muscle fibers can explain the pathological phenotype of mild cytochrome c oxidase deficiencies in mitochondrial myopathies.

[A comparison of trace element and isotope analysis in archeological bones (exemplified by a medieval bone series from Weingarten, Germany)]. / Spurenelement- und Isotopenanalyse in archäologischem Knochen im Vergleich (am Beispiel der mittelalterlichen Skelettserie von Weingarten, Deutschland).

The well established methods of isotope- and trace element analysis have been used as a reliable approach in archaeometry in order to reconstruct ecological and social parameters. Both methods offer access to palaeoecological information, however, frequently only one of the methods has been applied on the onegiven material. Up to now, isotope data are especially associated to the determination of food webs and palaeocliamtes, i.e. the position of the examined subjects within an ecological context is englightened. On the other hand, trace element analyses reveal knowledge about group specific nutrition and pollution with toxic substances. For the medieval human bone series of Weingarten (Germany), both methods have been applied independently. The results suggest special emphasis of diagenesis for the interpretation of trace element data: diagenesis and its impact on the stability of biological signals as well as consequences for data interpretation, which is dependent on the analysed phase of the material (mineral or gelatine) and its preservation.

Histopathological studies on the local reactions induced by complete Freund's adjuvant (CFA), bacterial lipopolysaccharide (LPS), and synthetic lipopeptide (P3C) conjugates.

The inflammatory reactions following subcutaneous application of adjuvants revealed characteristic pathological patterns. The injection of complete Freund's adjuvant (CFA) resulted in the formation of large lipid deposits encircled by an inflammatory reaction and concentrically arranged collagen bundles. Bacterial lipopolysaccharide (LPS) caused granulomatous aggregations of mononuclear cells with thrombotic vessel occlusions. Inoculation of the lipopeptide adjuvants induced accumulation of mononuclear cells with only minimal fibrotic changes which were resolved after day 28. Lipopeptide conjugates based on the head group tripalmitoyl-S-glyceryl-cysteinyl-serin (P3CS) can thus be used as effective immunogens and adjuvants without long-term tissue damage.

[Colonic cancer screening with KRYPTO-HAEM SSW. The results in 3015 persons]. / Dickdarmkarzinom-Screening mit KRYPTO-HAEM SSW. Ergebnisse an 3015 Personen.

In a factory 3015 individuals have been tested for occult blood in stool using the KRYPTO-HAEM SSW. Test results were positive in 100 individuals (3.3%). Subsequent investigations have revealed 6 carcinomas of the colon, one carcinoid in the cecum and adenomas in 9 cases. Eleven out of the 16 tumors detected were beyond the range of the rectoscope. The test was valued as false-positive in 42 individuals (1.4%). A cecum carcinoma and 5 adenomas were revealed by false-negative findings. The importance of case history and exact diagnostic clarification of a positive test is pointed out. The inclusion of the KRYPTO-HAEM test into basic medical care proved to be an adequate measure for early detection of colorectal tumors.

[Screening for colorectal cancer with a test for occult blood in stool (author's transl)]. / Screening auf kolorektalen Krebs mit einem Suchtest auf okkultes Blut im Stuhl.

Results of an occult-blood-test in 1 072 persons are reported. The test, recently registered as KRYPTO-HAEM, was developed by the Central Institute of Molecular Biology of the Academy of Sciences of the GDR. 27 patients (2.5%) had positive findings and by clinical examination 1 carcinoma of the sigmoid colon and 2 adenomas were detected. In 1 case (adenoma of the rectum) the test had a false-negative result. The findings were compared with own experiences with the HAEMOCCULT-Test. The KRYPTO-HAEM-Test is recommended for screening for colorectal tumors.

[Arteriomesenteric obstruction of the duodenum (author's transl)]. / Die arteriomesenteriale Duodenalstenose.

Survey of the clinical and diagnostic treatment of arteriomesenteric obstruction. Report on 4 cases of chronic obstruction and 2 cases of acute occlusion of the duodenum due to the root of mesenteric vessels. Indication of operation. Recommendation of retrocolic side-to-side duodenojejunostomy.