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Biomedical subjects

M Büttner

Publications and source records attributed to M Büttner.

At least 19 recordsLinked to original sources
PubMed1992

Photosynthetic reaction center genes in green sulfur bacteria and in photosystem 1 are related.

Oxygenic photosynthesis of chloroplasts and cyanobacteria involves two photosystems, which originate from different prokaryotic ancestors. The reaction center of photo-system 2 (PS2) is related to the well-characterized reaction center of purple bacteria, while the reaction center of photosystem 1 (PS1) is related to the green sulfur bacteria, as is convincingly documented here. An operon encoding the P840 reaction center of Chlorobium limicola f.sp. thiosulfatophilum has been cloned and sequenced. It contains two structural genes, coding for proteins of 730 and 232 amino acids. The first protein resembles the large subunits of the PS1 reaction center. Putative binding elements for the primary donor, P840 in Chlorobium and P700 in PS1, and for the acceptors A0, A1, and FeS center X are conserved. The second protein is related to the PS1 subunit carrying the FeS centers A and B. An adjacent third gene, not belonging to the reaction center, encodes a protein related to dolichyl-phosphate-D-mannose synthase from yeast. The different origins of PS1 and PS2 are discussed.

Amino Acid Sequence↗
PubMed1992

The photosystem I-like P840-reaction center of green S-bacteria is a homodimer.

An operon encoding the P840 reaction center of Chlorobium limicola f.sp.thiosulfatophilum has been cloned and sequenced. It contains two structural genes coding for proteins of 730 and 232 amino acids. The first protein resembles the large subunits of the Photosystem I (PS I) reaction center. Putative binding elements for the primary donor, P840 in Chlorobium and P700 in PS I and for the acceptors A(o), A(1) and FeS-center X are conserved. The second protein is related to the PS I subunit carrying the FeS-centers A and B. Since all our efforts to find a gene for a second, large subunit failed, the P840 reaction center probably is homodimeric.

Amino Acid Sequence↗
PubMed1991

Natural killer (NK) activity of porcine blood lymphocytes against allogeneic melanoma target cells.

Allogeneic PM/86 melanoma cells of Munich Troll miniature swine have been used for the demonstration of porcine peripheral blood NK cell activity. Compared with the specific lysis of xenogeneic K562-, U937- and Vero-target cells, NK cell-mediated cytotoxicity (NK-CMC) against PM/86 melanoma tumor cells was significantly lower in a 16 h chromium release assay. The target cell susceptibility to peripheral blood NK-CMC of both adult Troll miniature swine and German Landrace sows was very similar. Cold target inhibition assays revealed the allogeneic PM/86 melanoma cells to be the most powerful inhibitors of NK-CMC. Nylon wool non-adherent lymphocytes produced interferon (IFN)-alpha in different quantities upon contact with NK susceptible target cells. The NK effector cells could be stimulated to a higher lytic activity against all susceptible targets by a moderate dose of natural human interleukin-2 (nhuIL-2). The role of NK-CMC in melanoma tumor rejection and/or prevention of metastases is yet unknown in swine although porcine melanoma serves as a good model for the disease in man.

Animals↗
PubMed1991

Treatment of chronic stomatitis of cats by local paramunization with PIND-ORF.

33 cats, suffering from chronic stomatitis, were treated with orally given paramunity inducer PIND-ORF (local paramunization). As a control 39 cats in the same practice were treated with other conventional methods. The reconvalescence rate (healing without rezidives) of experimental animals was 42%. From control animals only 13% reached this status. Oral paramunization with PIND-ORF is recommended as an alternative treatment for hitherto existing therapeutic measures against chronic stomatitis.

Animals↗
PubMed1991

[Interferon in sheep].

There is only limited information on sheep interferon available. Recent publications have reported on: 1. an interferon (IFN) alpha subtype, which is secreted by the fetal trophectoderm into the lumen of the uterus between the 10th and 21st day of gestation. It was therefore named ovine trophoblast protein (oTP-1), and is responsible for signalling pregnancy to the ewe via high affinity receptors in the endometrium. It is thought that oTP-1 acts by directly influencing prostaglandin metabolism. 2. the role of lentivirus-induced interferon (LV-IFN) in the pathogenesis of Maedi/Visna. The results indicate that LV-IFN limits viral replication and therefore contributes to virus persistence and is also responsible for a chronic inflammatory process. 3. the mitogen- or antigen-dependent induction of ovine interferon gamma (IFN gamma) and its characterization.

Animals↗
PubMed1991

[Effectiveness of dental prevention programme for Swiss youth].

In the past few years, the caries research has reached a level for an effective prevention, that in Switzerland has been practiced already for 25-30 years. The results are conclusive and today I will show that the caries rate has been dramatically deduced. An adequate and regular fluoride delivery is the basis for an effective caries prevention. Also other important measures are optimal oral hygiene and a proper nutritional diet. In Switzerland, we are coming close to the two goals for the 5 year olds and for the 12 year olds set by WHO for the year 2000 for healthy teeth. In many Swiss communities, these two goals have already been reached. It seems that with group-prophylaxis, no noticeable improvement has been made against gingivitis. Group-prophylaxis begins in Kindergarten (ca. 4 years olds) and extends to the four years of ground school education. On entering the middle school level (ca. 11 year olds), the patient leaves the group-prophylaxis and receives individual prophylaxis instruction. Also, the substance matter changes from caries prophylaxis to gingivitis-prophylaxis. Carrying out the program are private local dentist through contract arrangements or the canton school dental clinic. The dentist delegates the prophylaxis program to specially trained personnel. Public enterprise finances the prophylaxis measurements in its entirety. Today there is a small group of patients showing a large susceptibility to caries. Certain prophylaxis test today demonstrate these risk factors. The caries risk is already from the mother or other persons in contact with the child at the Kindergarten age, or at the latest, at the time the child enters school.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Swiss organization of preventive dentistry].

As a result of 25--30 years of caries research practiced in Switzerland, a level for an effective caries prevention has been reached. The results are conclusive and show that at present the caries rate has been considerably reduced. An adequate and regular application of fluoride is the basis for an effective caries prevention. Other important measures are an optimal oral hygiene and a proper nutritional diet. In Switzerland, we are coming very near to the two aims set by WHO for the year 2000 in respect of healthy teeth, namely: a) half of the 5 years olds should be caries-free, b) 12 year olds should have no more than 3 carious teeth. In many Swiss communities, these two aims have already been achieved. Group prevention begins in kindergarten (ca. 4 year olds) and continues up to the fourth year of ground school education. On entering the middle school level (ca. 11 years olds), the patients leaves the group-prevention and receives individual prevention instruction. Also the substance matter changes from caries-prevention to gingivitis-prevention. It seems that with group-prevention, no noticeable improvement has been made against gingivitis. Carrying out the program are private local dentists with contract arrangements, or the canton's school dental clinic. The dentist delegates the prevention program to specially trained personnel. Public funds finance the prevention measures in its entirety. In the last few years we have discovered a small group of patients showing a higher caries-susceptibility despite the general improvement of oral hygiene.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1990

Corynebacterium parvum (Propionibacterium acnes): an inducer of tumor necrosis factor-alpha in human peripheral blood mononuclear cells and monocytes in vitro.

The present study investigates the potential capacity of the immunostimulant Corynebacterium parvum (C.p.) to induce tumor necrosis factor-alpha (TNF-alpha) in human peripheral blood mononuclear cells (PBMC) and blood monocytes (BMo) in vitro. Both at the mRNA and protein level, stimulation of PBMC and BMo upon C.p. induces TNF-alpha. Compared to the hitherto used TNF-alpha inducers in vitro such as Sendai virus, phytohemagglutinin or lipopolysaccharide the C.p. stimulus displayed a threefold stronger induction of TNF-alpha production (p less than 0.001). Using C.p. as an inducer it was possible to demonstrate that TNF-alpha production is regulated by prostaglandin E2; preincubation of the cells with prostaglandin E2 resulted in a reduced C.p.-mediated TNF-alpha production (p less than 0.001). Coincubation of interferon-gamma (IFN-gamma) together with C.p. led to an enhanced release of TNF-alpha, supporting the assumption that C.p. is a potent TNF-alpha inducer. The additive effect of IFN-gamma and TNF-alpha on the receptor level was demonstrated by addition of IFN-gamma antibodies to the PBMC cultures. Under these conditions TNF-alpha production, stimulated by C.p. and IFN-gamma, was decreased by 30%, compared to the production in assays supplemented with C.p. alone. From these data we conclude that C.p. is a new inducer of TNF-alpha in vitro and a useful tool to study TNF-alpha production of PBMC and BMo from either healthy donors or from patients.

Blotting, Northern↗
PubMed1990

Bare lymphocyte syndrome--combined immunodeficiency and neutrophil dysfunction.

A 4-year-old girl presented with recurrent infections. Immunoglobulin deficiency (serum and secretory IgA, serum IgG3) neutropenia and neutrophil dysfunction (defective spontaneous migration and chemotaxis) were found. T-lymphocyte counts were normal and they responded to phytohaemagglutinin but were not stimulated by Concanavalin A, pokeweed mitogen and microbial antigens in vitro. Delayed cutaneous hypersensitivity testing to purified protein derivative and candidin was negative. Despite bacille Calmette-Guérm vaccination and candidiasis, near normal beta-2-micro-globulin and human leucocyte antigen (HLA) class I concentrations were detected on mononuclear cells and phytohaemagglutinin-induced lymphoblasts. HLA class II antigens (HLA-DP, -DQ, -DR) were not expressed. These observations indicated a bare lymphocyte syndrome (BLS) type II. This is the first time neutrophil dysfunction has been noted in association with BLS.

Cell Movement↗
PubMed1990

[Recent information about the orf virus of small ruminants].

New scientific findings in the field of immunobiology and diagnosis of parapoxvirus ovis (Orf-virus) as the causal agent of a zoonosis are presented. The adaptation of Orf-virus to cell lines and its in vitro multiplication without difficulties offer the possibility for extensive studies into the biology of parapoxviruses. The development of monoclonal antibodies (MAB) against an attenuated Orf-virus strain (D-1701) led to the elaboration of a simplified, cheap and highly sensitive "antigen detection ELISA" as a diagnostic tool. Moreover the MAB's can be used to identify parapoxvirus in cells of infected tissues (indirect immuno-peroxidase technique) which is an important precondition for more detailed surveillance of the pathogenesis of parapoxvirus infections. The immunobiological behavior of the Orf-virus in its natural hosts (small ruminants) as well as in non-susceptible species (e.g. laboratory animals) is explained by the course of cellular and humoral immune reactions following infection or vaccination. The problems of combat measures against contagious ecthyma (scabby mouth) of sheep and the human Orf-virus infections are discussed.

Animals↗
PubMed1990

[Comparative studies of the paraspecific immunostimulation (paramunization) by bacterial lysates in bacterial infection models and in the cytotoxicity test].

Bacterial lysates of different bacterial strains (E. coli, B. bronchiseptica, P. haemolytica) were prepared by heating, acid- and alkaline-hydrolysis. Lysates were tested for their immunostimulating effect in bacterial infection models and with chromium 51 test demonstrating spontaneous (natural) cytotoxicity. Lysate production was standardized by protein- and Lps-determination. The alkaline-hydrolysis reduced toxicity of Lps and increased the content of soluble bacterial protein. Heating and acid-hydrolysis did not alter bacterial suspensions with respect to Lps-toxicity and protein-content. Mice infected with P. aeruginosa, P. multocida, E. coli and L. monocytogenes (5-10 LD50) had a significantly longer survival time after prophylactic immunostimulation with bacterial lysates than control animals. No protection was observed in immunostimulated mice infected with Erysipelothrix rhusiopathiae. In the Pseudomonas infection model, bacterial lysates prepared by alkaline-hydrolysis had a 10 times higher immunostimulating effect than lysates prepared by acid-hydrolysis or heating. Bacterial lysates stimulated spontaneous cytotoxicity of natural mouse peritoneal killer cells after intraperitoneal application. Whole bacterial lysates had a higher NK-activity as their corresponding purified lipopolysaccharide portion.

Adjuvants, Immunologic↗
PubMed1989

[Experimental detection of the paraspecific effects of purified and inactivated poxviruses].

The paraspecific effect of pox viruses i.e. stimulation of the nonspecific part of the complex immune system, was demonstrated in vitro and in vivo for 3 different types of virus (vaccinia virus, avipox virus, parapox virus). By means of purification, concentration and inactivation, it was possible to prove that the paraspecific effect is brought about by the pox virus particle per se. The effect is induced by certain epitopes in the complex structure of the virus and is independent of virus multiplication. Both purified pox viruses and inactivated, purified pox viruses stimulate NK cell activity, the CSA and the formation of interferon, and reach higher efficacy indices in a challenge test with baby mice using stomatitis vesicularis virus than non-purified and non-inactivated cell culture material. The degree of purity of the pox virus preparations was established using the electron microscope and monoclonal antibodies. The purified and concentrated pox virus preparations proved to be pyrogen-free; they were not toxic to baby mice in vivo. An endotoxin-induced effect could be ruled out. The broad paraspecific effect of pox viruses and their structural components lends itself to use as paramunity inducers in prophylaxis and therapy.

Animals↗