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Biomedical subjects

M Werner

Publications and source records attributed to M Werner.

At least 19 recordsLinked to original sources
PubMed1992

A new histological embedding method by low-temperature polymerisation of methyl methacrylate allowing immuno- and enzyme histochemical studies on semi-thin sections of undecalcified bone marrow biopsies.

A new procedure of embedding in methyl methacrylate (MMA) is introduced, which enables immunostaining by preservation of cellular epitopes. This could be achieved by reduction of polymerisation temperature from ca. 60 degrees C to 22 degrees C within the core of tissue blocks. Reduction of the polymerisation temperature is due to destabilisation of acrylate monomer, reduction of catalyst, exclusion of molecular oxygen, chemical initiation and reduction of environmental temperature. This results in good preservation of antigens and enzymes in the haematopoietic and lymphatic tissue of bone marrow as well as lymphoid, epithelial and mesenchymal markers in other tissues, comparable to paraffin embedding. Results are demonstrated by application of monoclonal and polyclonal antibodies and by demonstration of enzyme activity conventionally used in haematology.

Biopsy↗
PubMed1992

Effects of cytokines on growth in vitro of primary human renal cell carcinoma.

In clinical trials different haematopoietic active cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) have been proven to alleviate myelosuppressive side effects of intensive chemotherapy in different non-urological malignancies. On the other hand, these cytokines can directly stimulate the proliferation of cells originating from some non-urological tumours. To clarify the impact of these cytokines on the proliferative behaviour of human renal cell carcinoma (RCC), 29 previously untreated RCC tumours were prepared for culturing in vitro using the cell cluster technique. The success rate for growth in vitro was 82.8% (24/29). The malignant renal cells were treated with different cytokines (GM-CSF, G-CSF and interleukin-3) in different dosages. Cell number and proliferation rates detected by immunostaining were used for treatment evaluation. A dosage-dependent stimulation of cell growth could not be observed compared to untreated cells. From the data presented in this study, proliferative stimulation of RCC by administering colony-stimulating factors in clinical trials cannot be assumed.

Carcinoma, Renal Cell↗
PubMed1992

Chromosome analyses in patients with myelodysplastic syndromes: correlation with bone marrow histopathology and prognostic significance.

Chromosome analyses of bone marrow and peripheral blood cells were performed in a total of 51 patients with myelodysplastic syndromes (MDS) simultaneously with histopathological examination of resin-embedded bone marrow biopsies. Diagnosis of MDS was established by histopathology according to the French-American-British (FAB) classification, and reassessed by haematological data and clinical course. Clonal karyotypic changes were found in 30 of the 51 patients (59%): in 15 of 19 (79%) patients with refractory anaemia, 7 of 11 (64%) with refractory anaemia and excess of blasts (RAEB), 6 of 10 (60%) with RAEB in transformation, and 2 of 11 (18%) with chronic myelomonocytic leukaemia. The following three features of the histopathology revealed positive correlations with karyotype abnormalities: all cases of myelofibrosis in MDS (7/51) were accompanied by chromosome aberrations, microforms of megakaryocytes with reduced nuclear lobulation were observed in 18 of 30 cases with karyotype changes, and hypocellularity of haematopoiesis was associated with aberrations of chromosome 7 in 2 of 4 cases. No positive correlations were revealed between abnormal karyotypes and the transformation to acute leukaemia. The survival times were significantly decreased in patients with complex (3 and more) karyotype changes, when compared with patients with single (1-2) chromosome aberrations or normal karyotype, independently of the FAB classification.

Aged↗
PubMed1992

Immunohistochemical examination of routinely processed bone marrow biopsies.

Immunohistochemistry was performed on paraffin sections of 169 bone marrow biopsies fixed in a buffered methanol-formalin solution and decalcified with EDTA. The biopsies included specimens with normal hematopoiesis, and specimens that were affected by various hematological disorders as well as some metastatic carcinomas. The results demonstrate that a wide spectrum of antigens was preserved in routinely processed bone marrow biopsies, even after long-term fixation up to 12 days. Markers for granulopoietic cells were lysozyme, elastase, DAKO-M 1, and MT 1. Megakaryopoiesis was stained with glycoprotein IIIa, von Willebrand factor, and Ulex europaeus agglutinin (UEA), and erythropoiesis with LN 1. Normal lymphocytes as well as lymphoma cells of all non-Hodgkin's lymphomas tested were positive for leukocyte common antigen (LCA), and at variable degree, for MB 1, 4 KB 5, LN 1, LN 2, UCHL 1, or MT 1. Reed-Sternberg and Hodgkin's cells in Hodgkin's lymphomas were reactive with Ber-H 2, LN 2 and Dako-M 1. In plasma cell disorders, staining for immunoglobulin light chains gave best results. Metastatic carcinomas showed predominantly staining with EMA, and KL 1. A selected panel of specific cell markers is proposed, which proved to be helpful in routine bone marrow diagnosis in most cases.

Biopsy↗
PubMed1992

Antimicrobial susceptibilities of Campylobacter jejuni and Campylobacter coli isolated in Sweden: a 10-year follow-up report.

Resistance to erythromycin and doxycycline and more recently to fluoroquinolones has been reported to occur in Campylobacter spp. both in vitro and in patients treated with these antibiotics. The frequency of resistance to 14 antimicrobial agents in Campylobacter jejuni and Campylobacter coli isolated from patients infected in Sweden or abroad is described. For some agents, a comparison of susceptibility in strains of Campylobacter spp. isolated in 1978 with those isolated in 1988 is made. No general increase in in vitro resistance to antibiotics commonly used for the treatment of human gastroenteritis caused by C. jejuni or C. coli has occurred during the last 10 years in Sweden, which might be a consequence of strict antibiotic control. The numbers of strains from 1988 to 1989 resistant to ciprofloxacin and to norfloxacin included in this study (0.7 and 1.4%, respectively) are still fewer than those that were resistant to erythromycin (7.3%) or doxycycline (12.4%). There is, however, since 1989 to 1990 an indication of increasing resistance to these antibiotics.

Anti-Bacterial Agents↗
PubMed1992

RPC82 encodes the highly conserved, third-largest subunit of RNA polymerase C (III) from Saccharomyces cerevisiae.

RNA polymerase C (III) promotes the transcription of tRNA and 5S RNA genes. In Saccharomyces cerevisiae, the enzyme is composed of 15 subunits, ranging from 160 to about 10 kDa. Here we report the cloning of the gene encoding the 82-kDa subunit, RPC82. It maps as a single-copy gene on chromosome XVI. The UCR2 gene was found in the opposite orientation only 340 bp upstream of the RPC82 start codon, and the end of the SKI3 coding sequence was found only 117 bp downstream of the RPC82 stop codon. The RPC82 gene encodes a protein with a predicted M(r) of 73,984, having no strong sequence similarity to other known proteins. Disruption of the RPC82 gene was lethal. An rpc82 temperature-sensitive mutant, constructed by in vitro mutagenesis of the gene, showed a deficient rate of tRNA relative to rRNA synthesis. Of eight RNA polymerase C genes tested, only the RPC31 gene on a multicopy plasmid was capable of suppressing the rpc82(Ts) defect, suggesting an interaction between the polymerase C 82-kDa and 31-kDa subunits. A group of RNA polymerase C-specific subunits are proposed to form a substructure of the enzyme.

Amino Acid Sequence↗
PubMed1992

Inactivation of the protein phosphatase 2A regulatory subunit A results in morphological and transcriptional defects in Saccharomyces cerevisiae.

We have determined that TPD3, a gene previously identified in a screen for mutants defective in tRNA biosynthesis, most likely encodes the A regulatory subunit of the major protein phosphatase 2A species in the yeast Saccharomyces cerevisiae. The predicted amino acid sequence of the product of TPD3 is highly homologous to the sequence of the mammalian A subunit of protein phosphatase 2A. In addition, antibodies raised against Tpd3p specifically precipitate a significant fraction of the protein phosphatase 2A activity in the cell, and extracts of tpd3 strains yield a different chromatographic profile of protein phosphatase 2A than do extracts of isogenic TPD3 strains. tpd3 deletion strains generally grow poorly and have at least two distinct phenotypes. At reduced temperatures, tpd3 strains appear to be defective in cytokinesis, since most cells become multibudded and multinucleate following a shift to 13 degrees C. This is similar to the phenotype obtained by overexpression of the protein phosphatase 2A catalytic subunit or by loss of CDC55, a gene that encodes a protein with homology to a second regulatory subunit of protein phosphatase 2A. At elevated temperatures, tpd3 strains are defective in transcription by RNA polymerase III. Consistent with this in vivo phenotype, extracts of tpd3 strains fail to support in vitro transcription of tRNA genes, a defect that can be reversed by addition of either purified RNA polymerase III or TFIIIB. These results reinforce the notion that protein phosphatase 2A affects a variety of biological processes in the cell and provide an initial identification of critical substrates for this phosphatase.

Amino Acid Sequence↗
PubMed1992

Effect of mutations in a zinc-binding domain of yeast RNA polymerase C (III) on enzyme function and subunit association.

The conserved amino-terminal region of the largest subunit of yeast RNA polymerase C is capable of binding zinc ions in vitro. By oligonucleotide-directed mutagenesis, we show that the putative zinc-binding motif CX2CX6-12CXGHXGX24-37CX2C, present in the largest subunit of all eukaryotic and archaebacterial RNA polymerases, is essential for the function of RNA polymerase C. All mutations in the invariant cysteine and histidine residues conferred a lethal phenotype. We also obtained two conditional thermosensitive mutants affecting this region. One of these produced a form of RNA polymerase C which was thermosensitive and unstable in vitro. This instability was correlated with the loss of three of the subunits which are specific to RNA polymerase C: C82, C34, and C31.

Amino Acid Sequence↗
PubMed1992

[Borderline between Hodgkin and non-Hodgkin lymphomas with unfavorable clinical course: a clinical, histological and immunohistochemical analysis of 33 cases within the German Hodgkin Lymphoma Study].

Reevaluation of diagnostic biopsies from 502 patients who entered the German Hodgkin Therapy trial was performed by a panel of four pathologists. Classification revealed 90% of unambiguous Hodgkin-lymphomas (HL), 1.6% of Non-Hodgkin-lymphomas (NHL) and 8.4% of cases difficult to evaluate, reflecting to the well-known problem of the border between these 2 groups of lymphoma. As these cases had the worst prognosis, a second attempt of reclassification, including immunohistochemical studies, was made, resulting in final classifying of 25% of these cases as NHL, 50% as HL, and 25% as further unclassifiable. The most common differential diagnostic problem was separating pleomorphic nodular sclerosing HL from large cell NHL's and HL with rather few Hodgkin- or Reed-Sternberg-cells from Lennerts lymphoma or angioimmunoblastic lymphadenopathy. Immunohistochemistry was helpful for the differential diagnostic decisions in these individual cases. A very high percentage of these problem cases had initially entered the trial as lymphocyte depleted HL, and the large majority of deaths came from the large cell NHL group.

Diagnosis, Differential↗
PubMed1992

[Courses in health education as interventions in industry].

Following a brief overview of approaches to workplace health promotion and more specifically of health education courses the paper describes the objectives, contents and methods of a new health course for workers at elevated health risk. This course was developed as part of a comprehensive workplace intervention programme. It comprises three consecutive modules, coping with stress, nutrition, and fitness, each consisting of five 75-minute lessons. Due to intervals of several months between the modules the whole course takes about a year. Course objectives are to improve awareness of own health-related life-style, to mobilise health resources and to develop potentials for health action. Instructional methods include teaching of relevant knowledge, exchange of experience, observational tasks as well as practical exercises.

Curriculum↗
PubMed1992

[Carcinoid of the middle ear: a rare tumor with biphasic differentiation. Case report with special reference to immunohistochemistry and electron microscopy].

Progressive unilateral sensorineural deafness and tinnitus developed in a 59-year-old woman over a 1-year period. Clinical examination showed a tumor mass which almost completely filled the tympanic cavity, and grew around the auditory ossicular chain. Histological findings revealed the tumor to be a primary carcinoid of the middle ear. Neuro-endocrine differentiation was confirmed immunohistochemically by positivity for neuron-specific enolase, chromogranin, pancreatic polypeptide and synaptophysin. Using electron microscopy, neuroendocrine granules could be visualized. In addition, both light and electron microscopy revealed that cells had an epithelial differentiation with mucin granules while immunohistochemistry showed a positivity for cytokeratins. The detection of intermediary filaments (immunohistochemically with vimentin and under electron microscopy) was unique to this neoplasm and has to be considered in distinguishing the carcinoid tumor from the papillary adenoma of the middle ear. Tumor prognosis is excellent with radical extirpation from the middle ear. In the case presented, there has been no evidence for either recurrence or metastases 10 months after surgical resection.

Biomarkers, Tumor↗
PubMed1992

[Rosai-Dorfman syndrome. On the differential diagnosis of lymph node swelling].

The Rosai-Dorfman syndrome is a benign disease, one of its commonest affected sites being the cervical lymph nodes. This disease should be considered in the differential diagnosis of a cervical lymphadenopathy. The syndrome often begins with a chronic rhinitis, and is accompanied by sinusitis, tonsillitis or pharyngitis; blood tests indicate chronic infection. The pathogenesis of the disease is still unknown but may include infection or an abnormal autoimmune reaction. The diagnosis is established by the findings of characteristic histiocytes with haemophagocytosis. We report a female patient with persistent cervical lymph node swelling resistant to treatment. The cause was proved by histology to be a Rosai-Dorfman syndrome.

Diagnosis, Differential↗
PubMed1992

Myelofibrosis in primary myelodysplastic syndromes: a retrospective study of 352 patients.

In a retrospective study of 352 patients with primary myelodysplastic syndromes, 61 (17.3%) revealed myelofibrosis in bone marrow biopsies. The fibrosis was observed to occur mostly focally (41/61 cases), and collagen deposits were found very rarely (4/61). The histopathology of bone marrow biopsies revealed hyperplasia and disturbed differentiation in megakaryopoiesis; the frequency and grade of dysplasia in megakaryopoiesis increased with advancing myelofibrosis. Reticulin fibrosis occurred in all subtypes of MDS; however, there was a higher incidence in chronic myelo-monocytic leukaemia (CMMoL). The frequency of cytogenetic aberrations was significantly higher in the MDS cases with myelofibrosis, compared to the cases without fibrosis. Clinical data showed significantly lower values of haemoglobin and lower platelet counts in MDS with myelofibrosis. Life expectancy was reduced to 9.6 months, compared with 17.4 months in MDS without fibrosis. In refractory anaemia, the survival times were 10.0 months in MDS with myelofibrosis, compared to 28.9 months in MDS without myelofibrosis. 36.6% of the patients with MDS and myelofibrosis developed a transformation into ANLL during the course of the disease. Myelofibrosis therefore seems to herald a poor prognosis.

Adult↗
PubMed1991

Kinetic and thermodynamic characterization of the interaction between Q beta-replicase and template RNA molecules.

The specific binding of the RNA polymerase Q beta-replicase to some of its RNA template molecules, the single-stranded RNA variant MDV and also Q beta-RNA, was studied under various conditions by using a gel-retardation assay as well as filter retention. The dissociation of the replicase-RNA complex proceeds with first-order kinetics. The dependence of the dissociation rate constant on the concentration of monovalent ions suggests that there are three contacts between the midivariant (MDV) RNA and the replicase. Through analysis of the temperature dependence of the dissociation rate constant, values of 35 and 43 kJ/mol were obtained for the activation energies of complex dissociation between Q beta-replicase and the minus (-) and plus (+) strands of MDV, respectively. The bimolecular association is of second order with high rate constants that increase when the temperature is raised and decrease at higher salt concentrations. The equilibrium constants vary between 4.10(11) M-1 and 5.10(7) M-1, according to the reaction conditions. The temperature dependence of Ka gives delta H = -39 kJ/mol for MDV- and -47 kJ/mol for MDV+. Under nearly all conditions, distinct differences in the association and dissociation rates of plus and minus strands of MDV are observed. The binding of the small variant MDV to Q beta-replicase is three orders of magnitude stronger than the binding of the natural template Q beta-RNA.

Coliphages↗