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Biomedical subjects

H Wagner

Publications and source records attributed to H Wagner.

At least 379 records · Page 21Linked to original sources
PubMed1991

[Immunologic studies of plant combination preparations. In-vitro and in-vivo studies on the stimulation of phagocytosis].

The activity of phagocytosis was tested in the in vitro granulocyte test and the in vivo carbon-clearance-test in the mouse for an extract combination consisting of four plant extracts (Echinacea angustifolia, Eupatorium perfoliatum, Baptisia tinctoria and Arnica montana). In both immune models, a step by step stimulation of the activity of phagocytosis by the addition of the four plant extracts was shown with an increase in effectiveness of partially over 50% in comparison to the pure Echinacea angustifolia mono-extract. The extract combination showed also in both test models a higher efficiency than two other differently composed combination preparations and two Echinacea mono-preparations.

Animals↗
PubMed1991

Human gamma/delta T cells responding to mycobacteria.

Responses of human T cells against mycobacteria and mycobacterial components were analysed. T cells expressing either the alpha/beta or the gamma/delta T cell receptor were selected from human peripheral blood lymphocytes and proliferative responses to intact mycobacteria and to molecular mass-fractionated mycobacterial lysates were determined. alpha/beta T cells responded primarily to fractions greater than 30 kDa. Protease digestion abolished the stimulating activities for alpha/beta T cells, confirming that alpha/beta T cells respond to protein components. In contrast components recognized by gamma/delta T cells proved resistant to protease digestion. In limiting dilution studies, frequencies of proliferating gamma/delta T cells remained virtually unaltered by protease treatment of stimulating lysates, while those of alpha/beta T cells became almost undetectable. Furthermore, only few gamma/delta T cells responded to the 65 kDa heat shock protein. Our data indicate that, unlike alpha/beta T cells, gamma/delta T cells respond to mycobacterial components which are resistant to vigorous protease digestion.

Cells, Cultured↗
PubMed1991

[Admission of elderly patients in psychiatry: a study on the topic of "misplacement"].

Misplacement of the old in psychiatry gains in special importance based on the absolute and relative increase of this population. 117 patients have been announced for admission to the psychogeriatric department of the Zwiefalten State Mental Hospital within six months. Admission of 47 patients did not happen mostly as the result of advising the announcing person or refusing because of pure social indication. The remaining 70 patients and further 16 emergency patients have been admitted to the department of them about two thirds with cerebro-organic syndromes and one third with other mental diseases in old age. Mostly family doctors organized the hospitalisation, psychiatrists have been rarely engaged. In spite of severe reasons for hospitalisation, clinical treatment of patients with cerebro-organic syndromes turned out to be avoidable in more of the half of the cases, whereas it was justified in nearly 80% of the patients with other mental diseases in old age. As a whole, approximately the half of our admitted old patients would have not needed clinical treatment if there would exist enough qualified social care facilities, information deficits of the family doctors could be removed, and if psychiatrists would engage more in the treatment of mentally ill old persons.

Aged↗
PubMed1991

Lonidamine versus high-dose tamoxifen in progressive, advanced renal cell carcinoma: results of an ongoing randomized phase II study.

Sixty patients with metastatic renal cell carcinoma were entered into an ongoing randomized phase II study with lonidamine, 350 mg/m2 orally daily (arm A) and high dose tamoxifen, 150 mg/m2 orally daily for 6 months, afterwards 50 mg/m2 (arm B), until tumor progression. All patients had measurable disease and documented tumor progression prior to treatment. There were 1 complete and 1 partial remission among 19 evaluable patients in arm A (10.5%) and 2 complete and 1 partial remission among 25 evaluable patients (12%) in arm B. Objective responses were observed in pulmonary, nodal, and cutaneous metastases. In addition, in 63% and 64% tumor progression could be stopped in arm A and B, respectively. Median response duration was 100 days (range, 20-361) in arm A and 150 days (range, 28-355) in arm B. One year survival rate was 37.5% with lonidamine and 35% with tamoxifen. In arm A patients with tumor progression within 12 weeks after diagnosis of metastatic disease survived significantly shorter than patients with a longer interval (P less than 0.05). Nephrectomy or number and localization of metastatic sites failed to significantly influence probability of remission or survival. Toxicity was mostly mild to moderate. Four patients in the lonidamine arm had to discontinue treatment because of intolerable myalgias, which were immediately reversible. These data suggest that lonidamine and high-dose tamoxifen are moderately effective in widespread renal cell carcinoma where treatment intention is palliative.

Adult↗
PubMed1991

Lonidamine in high-risk breast cancer patients.

Lonidamine revealed synergistic effects with anthracyclines and alkylating agents in experimental investigations. It differs from conventional cytostatics by acting on the cell energy metabolism and also lacks their typical side effects; therefore it may be valuable to be combined with established chemotherapeutic regimens. Because in unselected patients the results of randomized studies may be influenced by differences in type and combination of prognostic factors, we defined strict entry criteria: no previous systemic palliative treatment, disease-free interval less than or equal to 2 years, measurable visceral metastases, number of tumor sites less than or equal to 2, no brain or bone metastases, World Health Organization performance status less than or equal to 2, age less than or equal to 55. In an ongoing rate, remission duration, time to treatment failure, and survival time in patients treated with vindesin 3 mg/m2 plus epirubicin 100 mg/m2 plus cyclophosphamide 600 mg/m2 (day 1, intravenous, repeated every 3 weeks) +/- lonidamine 600 mg/day orally. Eight of 12 patients achieved an objective remission (complete response 4, partial response 4), 1 patients had a stable disease, 2 patients experienced tumor progression; 1 patient is not yet evaluable for response. In spite of the intensity of the therapy no treatment interval prolongation was necessary. Main toxicities were myelosuppression, nausea, emesis, alopecia, and in patients treated with lonidamine, mild myalgia. The addition of lonidamine to polychemotherapy did not affect myelosuppression. Differences in remission rates or remission duration due to lonidamine could not yet be demonstrated.

Adult↗
PubMed1990

Transcription inhibition of SV40 by in vitro DNA methylation.

SV40 DNA was methylated in vitro with prokaryotic or eukaryotic DNA cytosine-5-methyltransferases and the inhibition of transcription by methylation was studied in Xenopus oocytes. Methylation with the prokaryotic HhaI or HpaII methyltransferases did essentially not inhibit transcription of SV40. Methylation with a rat liver methyltransferase led only to minor inhibition of the SV40 early genes, but to a complete shut shut off of the SV40 late genes. Partial methylation showed that methylation of both, the regulatory region and the 5' end of the SV40 late genes, was necessary for the effect on transcription. The TK gene could be inactivated by eukaryotic methylation of either the promoter and the first 50 nucleotides of the gene or the 3' rest of the gene. Insertion of the SV40 enhancer, not containing methylatable CpGs, into the TK upstream region, had no influence on the inhibition of TK gene transcription by methylation.

Animals↗
PubMed1990

DNA methylation inhibits transcription by RNA polymerase III of a tRNA gene, but not of a 5S rRNA gene.

Methylation of cytosine in the DNA inhibits the transcription by RNA polymerase II in higher eukaryotes, but has no influence on RNA polymerase I transcription. The effect on RNA polymerase III was unknown, so far. Two polymerase III genes: a type 1 5S rRNA gene and a type 2 tRNA gene were methylated in vitro with a purified eukaryotic DNA methyltransferase (EC2.1.1.37) and their transcription was analyzed in Xenopus oocytes. The 5S rRNA gene, an oocyte 5S rRNA gene from X. laevis which is subject to developmental inactivation, was not affected by methylation. Conversely, transcription of the tRNA gene was 80% inhibited by methylation with the eukaryotic methyltransferase. HhaI and HpaII methylation left its transcription unaffected.

Animals↗
PubMed1990

Induction of peripheral tolerance to class I major histocompatibility complex (MHC) alloantigens in adult mice: transfused class I MHC-incompatible splenocytes veto clonal responses of antigen-reactive Lyt-2+ T cells.

The efficacy and the mode of action of pretransplant transfusion with class I major histocompatibility complex (MHC)-disparate splenocytes in establishing a state of peripheral tolerance in adult mice is analyzed. Adult mice injected intravenously with a critical number of approximately 5 x 10(7) allogenic splenocytes accept skin grafts and develop chimerism in the peripheral lymphatic tissues, but not in thymus and bone marrow. In parallel, a split tolerance evolves: the frequency of class I MHC-reactive Lyt-2+ cytotoxic T lymphocyte precursor (CTL-p)- and interleukin 2 (IL-2)-producing T cells falls off in the peripheral lymphoid tissue, but remains unaltered intrathymically. In particular, high affinity CTL-p become clonally undetectable. In vivo generation of tolerant cells is cyclosporin A resistant, but dependent on recipient L3T4+ T cells. Loss of Lyt-2+ CTL-p- and IL-2-producing T cell precursors is not due to active suppression, but is caused by clonal anergy. Donor-derived chimeric cells positively selected 7 d after intravenous transfusion exhibit in vitro the hallmarks of veto cells, i.e., paralyze CTL-p reactive to donor-type class I MHC alloantigens. We conclude that the peripheral (split) tolerance induced in vivo by pretransplant transfusion operates because donor-type cells develop in vivo efficiently into "veto cells," which in turn induce a state of clonal anergy within antigen-reactive Lyt-2+ T lymphocytes.

Animals↗
PubMed1990

Binding of a Bolton-Hunter substituted homostatine analog to affinity-immobilized human renin.

The binding of a Bolton-Hunter reagent substituted homostatine analog, SDZ 213-776, to human renin was investigated at pH 6.5 and 7.4. At both pH values, SDZ 213-776 bound to human renin in a reversible and saturable manner. The binding characteristics conformed to a one-site binding model. The dissociation constant Kd, obtained at equilibrium, was four-fold lower at pH 6.5 that at pH 7.4 (0.94 nM vs 3.7 nM). Under non-equilibrium conditions, only the association kinetic constant k+1 was affected by pH. The results of the binding assay at pH 6.5 correlated well with those obtained in enzymatic assay at the same pH.

Antibodies, Monoclonal↗
PubMed1990

Transcription of HIV1 is inhibited by DNA methylation.

A possible role of DNA methylation as a factor in HIV latency was studied by methylating a HIV1-LTR-CAT plasmid in vitro and measuring its expression after transfection on Vero cells. Methylation with a eukaryotic DNA methylase resulted in a 70% inhibition of chloramphenicol acetyltransferase expression, in the absence as well as in the presence of the HIV1 trans-activator protein TAT in the cell. A similar degree of transcription inhibition was obtained by methylation of the only Hpa II site at position-143 in the HIV1-LTR with the bacterial Hpa II methylase. In contrast to the effect by eukaryotic methylation, the inhibition by Hpa II methylation could be partially reversed by cotransfection of the TAT gene. The reason may lie in an about 40% demethylation at the Hpa II site which was concomitantly observed.

Animals↗
PubMed1990

Primary responses of human T cells to mycobacteria: a frequent set of gamma/delta T cells are stimulated by protease-resistant ligands.

T lymphocyte subsets expressing either T cell receptor alpha/beta or gamma/delta were selected from human peripheral blood T cells and proliferative responses to molecular mass-fractionated mycobacterial lysates were determined. alpha/beta T cells primarily responded to fractions greater than 30 kDa whereas gamma/delta T cells preferentially reacted to fractions less than 3 kDa. Protease digestion abolished the stimulating activities for alpha/beta T cells, confirming that alpha/beta T cells respond to protein components. In contrast, components recognized by gamma/delta T cells proved resistant to protease digestion. In limiting dilution studies, frequencies of proliferating gamma/delta T cells remained virtually unaltered by protease treatment of stimulating lysates, while those of alpha/beta T cells became almost undetectable. Furthermore, only few gamma/delta T cells responded to the 65-kDa heat-shock protein. Our data indicate that, unlike alpha/beta T cells, gamma/delta T cells respond to mycobacterial components which are resistant to vigorous protease digestion.

Antigens, Bacterial↗
PubMed1990

Free flow electrophoresis for the purification of proteins: I. Zone electrophoresis and isotachophoresis.

The principles and some applications of free flow zone electrophoresis and isotachophoresis are described. The influence of (i) carrier electrolyte conductivity on the migration velocity and (ii) band shape on zone electrophoresis was investigated. The technique was found convenient for studying the effect of pH on the mobility of proteins to create a mobility curve. The purification of alcohol dehydrogenase from a crude yeast extract revealed the separation power of zone electrophoresis for complex protein mixtures. Without additional steps, a purification factor of 5.4, with a recovery of 97% alcohol dehydrogenase, was achieved. Free flow isotachophoresis was applied to the purification of immunoglobulins from human serum. Disadvantages of this technique are the time-consuming development of an optimized separation system and the empirical search for suitable spacers. Also, reaching of the steady state becomes increasingly difficult as the number of sample components increases.

Alcohol Dehydrogenase↗
PubMed1990

Scale-up of free flow electrophoresis: I. Purification of alcohol dehydrogenase from a crude yeast extract by zone electrophoresis.

The potential and limitations in scaling-up free-flow electrophoresis, with emphasis on zone electrophoresis, are demonstrated. Purification of alcohol dehydrogenase (ADH) from a crude yeast extract was chosen as a model for an industrial approach to enzyme purification. In zone electrophoresis the separation quality strongly depends on the pH and conductivity of the background electrolyte, its residence time and flow rate, as well as the applied voltage. Optimization of these parameters resulted in a purification factor of 5.3 and a yield of 96% ADH, using a Tris/HCl buffer, pH 8.0, and a conductivity of 1 mS/cm, with a residence time of 10 min at 500 V. The loading capacity of the method for a laboratory-sized free-flow electrophoresis apparatus was limited to a sample throughput of about 0.4 g/h. By increasing the chamber dimensions it was possible to purify the enzyme by a purification factor of 4.7 and a yield of 93% ADH, at a throughput of about 1 g total protein/h. By simultaneously applying the sample at 3 input positions the throughput could be increased to 2.75 g/h with a purification factor of 4.7 and an overall yield of 90%.

Alcohol Dehydrogenase↗
PubMed1990

Scale-up of free-flow electrophoresis: II. Purification of alcohol dehydrogenase from a crude yeast extract by field step electrophoresis and combined field step-zone electrophoresis.

Results of the purification of alcohol dehydrogenase (ADH) by field step electrophoresis and combined field step-zone electrophoresis are presented. In field step electrophoresis, optimization of voltage, residence time and pH of the sample solution led to a maximal purification factor of 2.8 and a yield of 89% ADH. The limit of loading capacity was reached at a protein concentration of the sample solution of approximately 4 g/L, allowing a maximal throughput of 1.14 g/h with a yield of 86% and a 2.8-fold purification in the Elphor VaP 22 apparatus. With a production scale apparatus a throughput of 2.07 g/h without any loss of separation quality could be achieved. By introducing the sample solution into the separation chamber through 3 inlets, simultaneously, the throughput was increased to 3.2 g/h with a purification factor of 2.7 and a yield of 82% ADH. For the combined field step-zone electrophoresis method a maximum purification factor of 3.6 and a yield of 80% ADH were achieved. The loading capacity was limited to a 4.13 g/L protein concentration of the sample solution, resulting in a throughput of 440 mg/h. Injecting the sample solution simultaneously into 3 inlets resulted in a maximum throughput of 1.92 g/h with 3.1-fold purification and a yield of 80% ADH. Zone electrophoresis, field step electrophoresis and a combination of both are compared with respect to resolution, throughput and the application potential in a protein purification scheme. A scale-up to 3 g/h is possible in zone electrophoresis and field step electrophoresis.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Dehydrogenase↗
PubMed1990

Free-flow electrophoresis for the purification of proteins: II. Isoelectric focusing and field step electrophoresis.

Two modes of continuous isoelectric focusing are described. The development of a natural pH gradient, consisting of a mixture of three buffer solutions, and the focusing behavior of human serum albumin is investigated. The advantages of isoelectric focusing in an artificial pH gradient of three buffer solutions are demonstrated on the purification of alpha-amylase from an E. coli protein extract. Furthermore the principle of field step electrophoresis is presented. The most important factors influencing the efficiency: (i) residence time, (ii) conductivity of the sample and (iii) sample zone width, are discussed. The use of a larger sized device to allow simultaneous multiple injections of the sample demonstrates the feasibility of scaling-up field step electrophoresis. This approach permits a throughput of about 20 mL sample solution per minute.

Bacterial Proteins↗