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Biomedical subjects

B Schmitz

Publications and source records attributed to B Schmitz.

At least 163 records · Page 9Linked to original sources

[Results of follow-up of untreated anterior cruciate ligament rupture].

A series of 90 patients, 85 males and 5 females, all with ACL-ruptures had a follow up between 5 and 12 years. All of them had a primary arthrotomy with or without meniscectomy but in no case an operative repair of the ACL-rupture was done. The most concomitant injury was a torn medial meniscus in 76.3%, a damaged lateral meniscus was found in 17.1%, chondromalacia was seen in 53%, either of tibia, femur or patella. Nearly 60% of the patients could resume their former sports activities in some cases on a lower level, whereas 33% had to change their sport or even had to give up any sport. 75%-80% of the patients with partial or total meniscectomy and 90% of those without meniscectomy estimated the outcome as good or fair. In contrast to this 61% rsp. 86% of the patients with partial or total meniscectomy had an osteoarthritis of grade III and IV, patients without meniscectomy in only 23%.

Adult↗

[A comparison of systemic radiotherapy, chemotherapy or local radiotherapy in the treatment of extensive small-cell bronchial carcinoma. Results of a randomized series].

Between 1982 and 1987 we carried out a prospective randomized study to compare the effectiveness of high-dose half-body irradiation (HBI) (A), intensive combined chemotherapy (B), and local or locoregional radiotherapy (C) in the therapy of extended small cell lung carcinoma (SCLC). 99 patients with a histologically proved SCLC were assigned to the three therapeutic groups of series: A = 31 patients, B = 37 patients, C = 31 patients. The median survival period showed a statistically significant advantage (p less than 0.01) for the chemotherapy group (B = 46 weeks) versus the two radiotherapy groups (A = 19 weeks, C = 23 weeks). The survival after half a year, one year, and two years also gave a clear advantage for the chemotherapy group. No difference was found between the radiotherapy groups A and C. The high-dose HBI gave no improvement of the sad therapeutic situation for the extended SCLC.

Antineoplastic Combined Chemotherapy Protocols↗

A small isoform of NADH:ubiquinone oxidoreductase (complex I) without mitochondrially encoded subunits is made in chloramphenicol-treated Neurospora crassa.

In mitochondria of Neurospora crassa grown in the presence of chloramphenicol a small form of NADH:ubiquinone reductase is made in place of the normal electron-transfer-complex I. This smaller enzyme has a molecular mass of approximately 350 kDa and consists of (at least) 13 different subunits which are all synthesized in the cytoplasm. The complex I which is normally found in Neurospora has a molecular mass of approximately 700 kDa and consists of around 30 different subunits, of which at least six are made in the mitochondria. Immunoblotting and peptide mapping suggest that the subunits of the small enzyme are homologous to subunits of the large enzyme, one subunit might even be identical. The small and the large NADH:ubiquinone reductases have the same high-affinity binding site for NADH but the two enzymes differ in the affinity and inhibitor sensitivity of the ubiquinone-binding site. The possibility is discussed that the small NADH:ubiquinone reductase is primitive isoform of complex I.

Binding Sites↗

[Subacute cerebral infarct: native and contrast medium-enhanced MRT].

Twenty-five patients with clinical and CT findings indicating supratentorial cerebral infarct were prospectively studied with MR. MR examinations were performed between the 3rd and 150th day after stroke. T2-weighted axial images were compared with T1-weighted sequences after i.v. administration of Gd-DTPA. T2-weighted images demonstrated parenchymal lesions in all 25 patients. Postcontrast T1-weighted images, however, displayed pathologic contrast enhancement in only 19 areas of infarction. In 5 of the 25 patients, the use of Gd-DTPA provided additional diagnostic information by demonstrating gyral contrast enhancement as a pattern typical for ischemia. In 2 of the 25 patients, pathologic contrast enhancement was observed in an area that was isointense to the surrounding brain tissue on the T2-weighted images. In one patient, Gd-DTPA improved differentiation between areas of subacute and chronic infarction. At present, in the patient with suspected cerebral infarction, MR imaging after i.v. administration of Gd-DTPA appears recommended when clinical findings and CT are equivocal.

Acute Disease↗

MS and NMR analysis of the cross-reacting determinant glycan from Trypanosoma brucei brucei MITat 1.6 variant specific glycoprotein.

The cross-reacting determinant glycan from Trypanosoma brucei brucei MITat 1.6 is known to contain galactose, mannose and non-acetylated glucosamine. The structural elucidation of this oligosaccharide has been impeded by an unusual non-glycosidic linkage to the peptide chain and a glycosidic linkage to inositol phosphate on either side of the oligosaccharide. Using two different approaches for the isolation of the glycan, namely hydrolysis to give the oligosaccharide directly or pronase digestion to yield the glycan-containing C-terminal glycophosphopeptide, the structure of this glycan was elucidated by mass spectrometry and 1H-NMR spectroscopy. There was evidence of heterogeneity in the glycan residue.

Animals↗

Lectin interactions with the variant surface glycoprotein from Trypanosoma brucei brucei incorporated into liposomes.

The variant specific surface glycoprotein from Trypanosoma brucei brucei is incorporated into lipid vesicles using 8M urea as an unfolding reagent. Pronase treatment of these proteoliposomes removes most of the protein, leaving a glycophospholipopeptide which is the membrane attachment site. We show here that lectins, specific for mannose and galactose are able to recognize oligosaccharide residues on these proteoliposomes, using a straightforward aggregation assay. The relevance of these results obtained with the liposome model system to the accessibility of the surface antigens in living trypanosomes is discussed.

Animals↗

A study of the membrane attachment site of the membrane-form variant surface glycoprotein from Trypanosoma brucei brucei using lipid vesicles as a model of the plasma membrane.

The incorporation of the membrane form and the soluble form of variant surface glycoprotein (mfVSG and sVSG) from Trypanosoma brucei brucei into liposomes has been investigated. It was found that selective incorporation of mfVSG into liposomes was possible in the presence of 8 M urea as a denaturing agent; sVSG, by contrast, was incorporated only poorly into liposomes. After proteolysis of mfVSG incorporated into liposomes, a compound was isolated from the liposomes which carries with it constituents of the glyophospholipid membrane anchor: ethanolamine, di-14:0-diglyceride and phosphatidylinositol were identified by electron impact and fast atom bombardment mass spectrometry, thus providing direct confirmation of the earlier findings of Holder [Holder, A.A. (1983) Biochem. J. 209, 261-262] and Ferguson et al. [Ferguson, M.A.J., Haldar, K. and Cross, G.A.M. (1985) J. Biol. Chem. 260, 4963-4968; Ferguson, M.A.J., Low, M.G. and Cross, G.A.M. (1985) J. Biol. Chem. 260, 14547-14555].

Animals↗

Cardiac metabolism of omega-(p-iodo-phenyl)-pentadecanoic acid: a gas-liquid chromatographic-mass spectrometric analysis.

The omega-(p-iodo-phenyl)-pentadecanoic acid (I-PPA) has been used successfully for the investigation of the cardiac metabolic activity and for the imaging of the myocardium (Machulla, H. J., M. Marsmann, and K. Dutschka. 1980. Eur. J. Nucl. Med. 5: 171-173). In the present study, the metabolic fate of I-PPA in the perfused rat heart was investigated. After application of I-PPA to the perfused rat heart, lipids were extracted, separated by thin-layer chromatography, and transesterified. The gas-liquid chromatographic-mass spectrometric (GLC-MS) analysis yielded the following results. Heart triglycerides contained 73% of the recovered I-PPA; only small amounts of unesterified I-PPA were found in the heart. This finding is in good agreement with the radioactivity distribution determined simultaneously. Three metabolites could be detected and characterized by GLC-MS: omega-(p-iodo-phenyl)-propionic acid, omega-(p-iodo-phenyl)-propenoic acid, and p-iodo-benzoic acid. These short chain metabolites were found only in the perfusion medium demonstrating that they are not enriched but rapidly eliminated from the perfused rat heart.

Animals↗

The role of antibody and complement in the cellular response to Trypanosoma congolense.

The in vitro cytotoxic response of bovine granulocytes and monocytes and of murine peritoneal macrophages against Trypanosoma congolense in the presence of antibody, antibody plus complement or complement alone was assessed using luminol aided chemiluminescence as a second parameter for effector cell activation. Neither cell type exhibited any trypanolysis exceeding that of antibodies and complement alone. The kinetics of the chemiluminescence response in the course of these reactions closely correlated with the trypanocidal activity of the antibody preparation used, suggesting effector cell activation as a response to antibody-mediated immobilization and damage of the trypanosomes. From these results and electron microscopic investigations we conclude that antibody- or complement-dependent cell-mediated cytotoxic reactions do not play a significant role in the defence of T. congolense infection, neither by extracellular lysis nor killing of ingested parasites.

Animals↗

[Left ventricular basal fibrous myocardial aneurysm in a 3-week-old girl].

A congenital bulging of the myocardial wall is a rare finding; little is known about its etiology and clinical course. The case of a 3-week-old girl in whom rapidly progressive cardiac insufficiency occurred after a completely normal postnatal development is described. Selective ventricular angiography revealed ventricular malfunction and an akinetic area occupying 57% of the basal free left ventricular wall. The child died in acute cardiac failure. Autopsy disclosed a basal fibrous aneurysm which extended to 34% of the free ventricular wall. There was no indication of a coronary or inflammatory etiology, so a focal disorder of myocardial architecture was presumed. Congenital bulging of the ventricular wall can be divided into broad-based aneurysms and diverticula, the latter being connected with the ventricle by a small orificium. A further distinction can be made on the basis of localization and histology. A reclassification of the congenital bulging of the left ventricular wall presented in the literature showed that apical muscular diverticula are the most frequent, whereas only four cases of fibrous aneurysms were reported. Differences were found, with regard to the distribution of age and race, the clinical course, and the possible etiology.

Diagnosis, Differential↗

Cellular response and resistance to the primary infection of rats and mice with Nematospiroides dubius.

LEWIS rats, in contrast to NMRI mice, have been found to be resistant to an oral infection with Nematospiroides dubius (Baylis, 1926). Comparative studies of the peritoneal response to infection showed a strong increase in the cell number predominantly of eosinophilic and neutrophilic granulocytes in rats, whereas in mice only a weak reaction occurred. As shown by the chemiluminescence response to either antibody--or complement-coated larvae, the granulocyte reaction caused an increased production of toxic oxygen species by the peritoneal cells. Purified granulocytes from rats or mice showed about a ten-fold higher oxidant generation than macrophages. The higher metabolic activity of granulocytes of either species resulted in rapid and strong killing of antibody or complement-coated infective larvae by granulocytes of either species, whereas macrophages failed to express a significant larvicidal potency. From these results we concluded that the activated oxygen species derived from the metabolic burst of granulocytes are essential for an effective control of the primary infection with N. dubius. This suggests that the rapid and strong granulocyte response may form the basis of the resistance in rats. Thus, in mice, the ability of N. dubius to prevent the granulocyte response may serve as an escape mechanism of the parasite.

Animals↗

Unimpaired histone synthesis in human fibroblasts infected by human cytomegalovirus.

Serum-starved human foreskin fibroblasts were infected by human cytomegalovirus (Towne strain) that is thought to induce DNA replication in host cells during lytic infection. At various times postinfection, the cultures were pulse labeled with either 3H-thymidine or 14C-thymidine and 3H-lysine to examine DNA synthesis and histone synthesis, respectively. Isopycnic centrifugation of labeled DNA in CsCl revealed that precursor incorporation into host-cell DNA was enhanced over the control around 24 h postinfection and decreased after onset of viral DNA synthesis which reached a peak around 72 h postinfection. For analysis of histones 3H-lysine-labeled proteins of lysates of unfractionated cells and of chromatin preparations were subjected to polyacrylamide gel electrophoresis in presence of sodium dodecyl sulfate and subsequent fluorography. Comparison of the fluorograms from the various pulses postinfection suggested that 3H-lysine incorporation into histones exhibited no major variations concurrent with the changes of host-cell DNA synthesis. In contrast, herpes simplex virus type 1 was found progressively to extinguish histone synthesis in the course of the cellular infection. Furthermore, histone synthesis in phosphonoacetic acid-treated cytomegalovirus-infected cultures was not enhanced over that in mock-infected controls. These observations do not support the view that human cytomegalovirus induces host-cell DNA replication under the conditions used.

Cell Line↗