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R Herrmann

Publications and source records attributed to R Herrmann.

At least 181 records · Page 10Linked to original sources
PubMed1995

Nonradioactive quantification of mdr1 mRNA by polymerase chain reaction amplification coupled with HPLC.

We describe a new strategy for quantifying mRNA by using polymerase chain reaction (PCR) coupled with HPLC. PCR-amplified products are directly analyzed with a specific HPLC column and are quantified by standardization against a housekeeping gene, beta-actin. To evaluate the experimental conditions, we examined the multidrug-resistance-associated mdr1 gene expression in two drug-sensitive cell lines (RPMI-8226 and KB-3-1) and in their drug-resistant sublines. This revealed a significant overexpression of the mdr1 gene in chemoresistant sublines that paralleled the degree of in vitro drug resistance and the amounts of mRNA determined by other methods. Results were consistently reproducible, with imprecision (CV) < 25%. The reverse transcription option PCR/HPLC protocol described here is a sensitive, nonradioactive method for quantifying mdr1 mRNA in cell lines or clinical tumor samples, and can be applied to the simultaneous quantification of several mRNA species.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

[Testing of bioequivalence of a new sotalol hydrochloride preparation in comparison to a standard formulation].

An investigation on the bioavailability of a new tablet with 160 mg sotalol hydrochloride (CAS 959-24-0, Rentibloc 160), was performed in a two-way cross-over study with 16 volunteers. The relative bioavailability with respect to a reference preparation for AUC0-infinity was 98.1% and for Cmax 100.8%. A positive decision for bioequivalence derived from the usual confidence intervals for both parameters. The difference in tmax showed no clinical relevance. The new formulation is bioequivalent to the reference.

Adult↗
PubMed1995

Matching for MHC haplotypes results in improved survival following unrelated bone marrow transplantation.

Unrelated bone marrow donor-recipient pairs were assessed retrospectively for matching of the HLA-B, -C region (beta-block) and HLA-DR, DQ region (delta block) of the major histocompatibility complex (MHC) using a new DNA-based method referred to as MHC-block typing. The method utilises non-HLA DNA polymorphisms in the MHC as markers of blocks of ancestral haplotypes. Kaplan-Meier analysis of recipients who were matched at both the beta- and delta-blocks revealed a 6 months survival of 54%. Survival was better than for patients who were matched only by conventional criteria, including SSO-typing for class II.

Adult↗
PubMed1995

Correlation of bone marrow minimal residual disease and apparent isolated extramedullary relapse in childhood acute lymphoblastic leukaemia.

We have used a polymerase chain reaction (PCR) technique capable of detecting one leukaemic cell in 10(5) normal cells to monitor minimal residual disease (MRD) in a retrospective study of childhood ALL. We were particularly interested in comparing MRD findings in patients in long-term remission, bone marrow relapse and apparent isolated extramedullary relapse (EMR). Archival slides were initially studied from 21 patients. However, on subsequent analysis, only 15 patients were informative at the molecular level. All seven patients with EMR had evidence of MRD in the bone marrow at the time of relapse. Five of the seven also had evidence of bone marrow MRD prior to EMR. In one of the seven patients, MRD was not detected in a bone marrow sample studied 5 months prior to EMR. The remaining EMR patient was not studied prior to EMR. Of five patients who remained in long-term remission (mean 144 months), three did not have detectable MRD at the end of induction therapy (2 months) and all five were MRD-negative at the end of treatment (36 months). This contrasts with the three patients who relapsed in the bone marrow at 8, 15 and 88 months post-treatment and who had evidence of MRD at the end of therapy.

Bone Marrow↗
PubMed1995

A plant lectin derived from Viscum album induces cytokine gene expression and protein production in cultures of human peripheral blood mononuclear cells.

A plant lectin from Viscum album (ML-I) has been shown to increase the number and cytotoxic activity of natural killer cells and to induce antitumor activity in animal models. However, the mechanisms underlying the effects of ML-I on natural host defenses are unknown. After 24 h incubation of peripheral blood mononuclear cells in the presence of 10 and 1 ng/ml of ML-I, mRNA expression and secretion of a panel of cytokines were evaluated by reverse polymerase chain reaction and by ELISA, respectively. The lectin induced expression of interleukin (IL)-1 alpha, IL-1 beta, IL-6, tumor necrosis factor-alpha, interferon-gamma, granulocyte-monocyte colony-stimulating factor and IL-10 genes but no expression of IL-2 and IL-5 genes could be detected. Regarding cytokine secretion, IL-6 and TNF-alpha production was induced by 10 ng/ml ML-I. On the other hand, IL-10 secretion was only stimulated by 1 ng/ml lectin. No production of IFN-gamma or, as expectable, IL-2 could be detected. In addition, ML-I increased the percentage of HLA-DR+ T lymphocytes in vitro. In tests performed on whole blood, monocytes and granulocytes bound the fluorescence-conjugated ML-I molecules to a higher degree than lymphocytes. Expression of IL-1 beta and IFN-gamma genes could also be observed upon ML-I stimulation of nonadherent cells. These results suggest that lectin-sugar interactions on the cell surface of immunocompetent cells can induce cytokine gene expression and protein synthesis.

Cells, Cultured↗
PubMed1994

[gamma-heavy chain production as an epiphenomenon in non-Hodgkin's lymphoma].

A 46-year-old woman was found to have localized lymphoplasmocytic lymphoma (low-malignancy non-Hodgkin lymphoma). Repeated recurrences required various chemotherapy courses with different drugs. Gamma heavy chains in serum and urine, as well as in blast cells in bone marrow, were first found 3 years later as part of a follow-up examination. When the lymphoplasmocytic lymphoma subsequently changed into a highly malignant disseminated large-cell lymphoma, the monoclonal gamma heavy chain-producing components no longer occurred. During continuing treatment and presumably selection of different cell clones the now terminal chemotherapy-resistant lymphoma again produced biclonal IgG heavy chains. The gamma heavy chain production added little to the histomorphological characterization of the underlying lymphoma, as well as its treatment and prognosis.

Combined Modality Therapy↗
PubMed1994

[Which way ahead? Carcinoma of the exocrine pancreas, the gallbladder and the bile ducts--nonsurgical therapy in the locally advanced and in the metastasized stage].

Carcinomas of the pancreas, gallbladder and bile ducts in inoperable stages can be treated with chemotherapy, radiotherapy and a combination of both modalities. Therapy is always palliative. In the past 20 years treatment results have not improved. Patients treated should be entered in controlled clinical studies with new substances randomized versus less toxic 5-FU or optimum supportive care. Pain and jaundice can be relieved by radiotherapy, bypass surgery and stent insertion. The choice of an option should be made according to patient characteristics and risk factors, as well as the possibilities and experience of the treating center.

Aged↗
PubMed1994

[Isolation ward: initial experiences after 4 years].

UNLABELLED: Since October 1988 there has been an isolation ward at Basle Cantonal Hospital. Its purpose is to treat patients with high dose chemotherapy and bone marrow transplantation under protective isolation and by standardized criteria. The isolation ward has two sub-units, viz. the reverse isolation for neutropenic patients (8 single room units) and the LAF unit (5 laminar airflow units) for allogeneic bone marrow transplantation (BMT). Up to July 1992, 287 patients (152 males and 133 females) required 527 hospitalizations. The median age was 41 (5-82) years in the reverse isolation unit and 28 (4-61) years in the LAF unit. Bed occupation was 90% and 82% throughout the period. 71% of patients were from the Basle area and the rest from elsewhere in Switzerland or from other countries. DIAGNOSIS: acute leukemias (112); myelodysplastic or myeloproliferative syndromes (52); severe aplastic anemia or agranulocytosis (46); lymphoproliferative syndromes (50); solid tumors (28). Indications for hospitalisation: BMT (107); complications after BMT (infections, GvHD) (63); chemotherapy on protocols of SAKK (105); other chemotherapies (64); antilymphocyte globulin or growth factor treatment (27); splenectomies (18); neutropenic fever (62); patient work-up (59); terminal care (20). Patients in reverse isolation were hospitalized for a median 17 (1-142) days; in the LAF unit for 52 (1-121) days.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

What is a realistic frontal-offset test procedure?

With an increasing number of vehicles satisfying the FMVSS 208 Flat Barrier Impact Test and increasing belt usage, a high reduction of occupant injuries in general and a change from acceleration-induced to intrusion-induced injury mechanisms has been observed in Europe. The significance of intrusion-induced injury mechanisms associated with offset frontal impacts is assuming greater importance. Beginning in 1978, in response to this challenge, Mercedes-Benz has emphasized front structural countermeasures that have been found to be effective in the frequent asymmetrical frontal impacts. As an internal test, an offset impact with 40% overlap against a rigid barrier was defined. The relationship between actual accident frontal-overlap damage and barrier-test overlap values is explored in the paper. The results support the view that if a test of this type and associated design countermeasures were adopted by all vehicle manufacturers, a significant reduction of injuries would take place.

Accidents, Traffic↗
PubMed1994

Identification and characterization of hitherto unknown Mycoplasma pneumoniae proteins.

Eleven hitherto unknown Mycoplasma pneumoniae proteins were identified and characterized with respect to their size and subcellular location. This was carried out through the construction of in vitro gene fusions between a modified mouse dehydrofolate reductase (dhfr) gene and selected regions (cosmid clones) of the M. pneumoniae genome and expressing them in Escherichia coli. Positive clones were identified using antibodies against specific fractions of M. pneumoniae. The deduced protein sequences of 11 out of 30 clones did not show significant homologies to known proteins in protein data-bank searches. Monospecific antibodies against these 11 fusion proteins were used to determine the size and cellular location of the corresponding M. pneumoniae proteins by immunoscreening Western blots of SDS-acrylamide gels from M. pneumoniae cell extracts.

Animals↗
PubMed1994

Spatial arrangement of gene products of the P1 operon in the membrane of Mycoplasma pneumoniae.

The spatial arrangement of three P1 operon-encoded proteins--attachment protein P1 (ORF5 gene product) and the ORF6-derived proteins of 40 and 90 kDa--in the membrane of Mycoplasma pneumoniae M129 was investigated by nearest-neighbor analysis. For these studies, the homobivalent, thiol-cleavable, and nonmembrane-permeating cross-linking reagent 3,3'-dithiobis(sulfosuccinimidylpropionate) (DTSSP) was used. The cross-linked proteins were isolated by immunoprecipitation with antibodies directed against fusion proteins of selected regions of the 40-kDa, the 90-kDa, or the P1 protein. The individual components of the immunoprecipitated protein complexes were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, autoradiography, and immunoblot analysis. This study showed that the P1 protein, the ORF6 gene product, and an unidentified 30-kDa protein were linked to each other in the intact bacterial membrane by the reagent DTSSP, indicating that these proteins are located at a maximal distance of 12 A (1 A = 0.1 nm) on the tip structure of M. pneumoniae.

Adhesins, Bacterial↗
PubMed1994

Sequence divergence in the ORF6 gene of Mycoplasma pneumonia.

The ORF6 gene product of Mycoplasma pneumoniae is involved in a yet-unknown manner in the adhesion of the bacterium to its host cell. Part of the ORF6 gene is a repetitive DNA sequence (RepMP5), about 1,900 bp long. Seven additional similar copies of RepMP5 are dispersed on the genome. In the independently isolated strains M. pneumoniae M129 and FH, the RepMP5 copies residing in the ORF6 gene are not identical. Two conserved regions, ranging from nucleotides 1 to 799 and from nucleotide 1795 to the end of the gene, border a variable region, ranging from nucleotides 800 to 1794. This variable region differs in DNA sequence and by 201 bp. Analysis of RepMP5 copies outside the ORF6 gene showed that both M. pneumoniae M129 and M. pneumoniae FH carry a RepMP5 copy on a 6-kbp EcoRI fragment which has the same DNA sequence as the variable region of RepMP5 in the M. pneumoniae FH ORF6 gene. According to these data, a switch from the M. pneumoniae M129 ORF6 gene to the M. pneumoniae FH ORF6 gene could take place by gene conversion.

Bacterial Adhesion↗
PubMed1994

Gene expression analysis by a competitive and differential PCR with antisense competitors.

We report a sensitive method for the reproducible and accurate measurement of gene expression from small samples of RNA. This method is based on a combination of two PCR techniques: First, an endogenous reporter gene and the gene of interest are simultaneously amplified in one tube after random-primed reverse transcription (RT) of RNA (differential RT-PCR). Second, exogenous homologous fragments of both genes with artificially introduced mutations are added and coamplified in the same reaction (competitive PCR). The first-strand cDNA, and the mutated antisense homologues of the reporter as well as the target gene compete for their respective primers and are therefore amplified with equal efficiencies. After PCR, restriction enzyme digestion allows visualization of the quantitative differences between the four resulting reaction products. The ratios of products that competed during PCR provide the quantitative information. The initial amount of a specific cDNA can be calculated from any competitor/cDNA ratio of reliably measurable PCR product amounts. Extensive competitor titration to experimentally approach the equilibrium is therefore unnecessary. The differential counterpart of competitive and differential RT-PCR (CD-RT-PCR) allows expression of the levels in reference to a reporter gene. MDR1 expression was determined in tumor cells by CD-RT-PCR.

Binding, Competitive↗
PubMed1994

[Hepatocellular carcinoma: systemic chemotherapy, perspectives of gene or immunotherapy].

The systemic chemotherapy of hepatocellular carcinoma with single agent or combination chemotherapy has not resulted in reproducible response rates above 20%. Correspondingly, an effect on the survival of the treated patient population has not been shown so far. The most effective single agent is doxorubicin, which should, however, not be used outside of clinical studies in the systemic treatment of hepatocellular carcinoma. The results of hormonal treatment of hepatocellular carcinoma are also disappointing: the response rates of agents like tamoxifen, ketoconazol, nilutamid, LHRH-agonists or megestrol are usually below 10% and the survival of patients can not be improved. New approaches that are currently tested in vitro and in mouse models are pharmacological or immunological interactions with tumor cells that make use of molecular biology techniques and are summarised under the term "gene therapy". Some of these projects are in clinical phase I studies and first results can be expected in the next three to five years.

Antineoplastic Agents↗