Biomedical subjects

J Beuth

Publications and source records attributed to J Beuth.

At least 73 records · Page 4Linked to original sources

PubMed1992

Influence of 12 antibiotics on antitumor immunity in BALB/c-mice.

The effects of 7 days' chemotherapy with penicillin G, piperacillin, mezlocillin, cephalothin, cefamandole, cefotaxime, gentamicin, amikacin, streptomycin, rifampicin, doxycycline, and clindamycin on local tumor growth and metastatic lung colonization were studied in an experimental tumor model (BALB/c-mouse-sarcoma L-1). The antibiotic dosages administered to mice were calculated on a body weight basis from doses recommended for human therapy. Except for mezlocillin, piperacillin, rifampicin and doxycycline, antibiotic treatment did not significantly influence local tumor growth, lung colonization and immune functions. Whereas mezlocillin exerted positive (tumor suppressive) or negative (tumor promoting) effects depending on the chemotherapy schedule, tumor growth and spread were significantly increased independent of the timing scheme after rifampicin or doxycycline treatment. Since certain immune functions (delayed type hypersensitivity; proliferation of spleen lymphocytes) were significantly suppressed after administration of mezlocillin, rifampicin and doxycycline, a correlation between antimicrobial chemotherapy and tumor progression may be possible.

Animals↗

PubMed1992

Antibacterial in vitro-activity of meropenem against 200 clinical isolates in comparison to 11 selected antibiotics.

The antimicrobial activity of meropenem, a new parenteral carbapenem, was tested in vitro by an agar dilution method against 200 clinical isolates (gram-negative/positive aerobes and anaerobes). Meropenem was compared with imipenem, ceftazidime, cefotaxime, piperacillin, ciprofloxacin, gentamicin; and metronidazole, cefoxitin, chloramphenicol, clindamycin, vancomycin when appropriate. Meropenem and imipenem exhibited an extended spectrum of activity with low minimal inhibitory concentrations (MICs). Only one strain each of Enterococcus faecium and Pseudomonas (Xanthomonas) maltophilia were resistant. Of the carbapenems, imipenem was slightly more active against Enterococcus faecalis, Streptococcus agalactiae, and staphylococci, but meropenem was obviously more active against enterobacteriaceae and Clostridium perfringens. Both, meropenem and imipenem had similar activities towards Pseudomonas aeruginosa, Acinetobacter calcoaceticus, Streptococcus pyogenes and Bacteroides sp. All other antibiotics tested were less potent than the carbapenems with the exception of ciprofloxacin which generally exhibited similar antibacterial activities, except for anaerob microorganisms.

Anti-Bacterial Agents↗

PubMed1992

Etiology and antibiotic susceptibility of bloodstream Streptococcus sp.

249 episodes of Streptococcus bacteraemia in hospitalized patients were evaluated for both clinical and microbiological features. Specification of the isolates demonstrated that infective endocarditis was predominantly associated with Streptococcus sanguis and Streptococcus bovis whereas Streptococcus pyogenes and Streptococcus milleri were the most common cause of local and/or systemic infections. In vitro-susceptibility tests towards 9 selected antibiotics proved that beta-lactam antibiotics are potent compounds for the treatment of Streptococcus sp. with the exception of enterococci; that ampicillin turned out to be highly effective against enterococci; and that vancomycin may be regarded as a potent alternative in the treatment of streptococcal infections.

Anti-Bacterial Agents↗

PubMed1992

Thymocyte proliferation and maturation in response to staphylococcal lipoteichoic acid.

Lipoteichoic acid (LTA) from Staphylococcus saprophyticus strain S1 could be shown to induce thymocyte proliferation and maturation in BALB/c-mice after systemic administration. The increase in thymocyte numbers per mg organ weight was statistically significant. Determination of thymic lymphatic subsets revealed a considerable up-regulation of mature cells expressing helper/inducer (L3T4) or cytotoxic/suppressor (Lyt-2) phenotypes. Thus administration of staphylococcal LTA obviously accelerated murine thymocyte proliferation and maturation. Counts of BALB/c-mouse peripheral blood lymphocytes (PBL) revealed no evident fluctuation within one week after LTA administration, however, statistically significant increases could be detected two weeks after treatment. The determination of activated PBL expressing IL-2 receptors suggested that injection of staphylococcal LTA apparently induced an immunostimulation since those cells were significantly enhanced within one week after LTA administration.

Animals↗

PubMed1992

Propionibacterium acnes-metabolites inhibit experimental lung metastasis of murine sarcoma L-1 in BALB/c-mice.

Adhesive interactions between tumor cells and host tissue occur at several stages of metastasis. Such interactions might be inhibited by microbial metabolites resembling the binding regions of matrix molecules. Certain metabolite sequences including Gly, Asp, Arg, and Ser (GAAS) proved to be critical for cell interactions, e.g. with fibronectin. In vitro, the rosette formation of murine pulmonary cells and sarcoma L-1 cells decreased significantly in the presence of Propionibacterium acnes-metabolites rich in GAAS. In vivo, coinjection of Propionibacterium acnes-metabolites and sarcoma L-1 cells significantly inhibited the formation of lung colonies in BALB/c mice. The inhibition of lung colonization by these metabolites appeared to be noncytotoxic and obviously did not result from impairment of cellular tumorigenicity.

Amino Acid Sequence↗

PubMed1991

Chemiluminescence response of human polymorphonuclear leukocytes induced by purified, latex attached Klebsiella fimbriae.

Type 1 fimbriae (T1F) and type 3 fimbriae (T3F) were isolated from Klebsiella species, purified, attached to latex beads and tested for their ability to stimulate human polymorphonuclear leukocyte (PMNL) oxidative activity. The luminol dependent chemiluminescence assay was used to evaluate the response of phagocytes. Latex particles coated with type 3 fimbriae (1-T3F) induced a significantly higher chemiluminescence response than those with type 1 fimbriae (1-T1F). Opsonization of 1-T1F with pooled human serum induced chemiluminescence responses which were statistically significantly enhanced as compared to opsonized 1-T3F and both kinds of non-opsonized fimbriae.

Fimbriae, Bacterial↗

PubMed1991

Staphylococcal lipoteichoic acid exerts growth factor-like activity towards human and murine cells.

Lipoteichoic acid (LTA) was extracted from Staphylococcus saprophyticus strain S1 and tested for the capacity to induce hematopoietic and lymphatic cell proliferation. As compared to nontreated cells, the number of human bone marrow cells significantly increased in the presence of low LTA concentrations. Optimal growth was observed on the fifth day of in vitro incubation. After exposure to LTA, the lymphocyte proliferation rate also increased in a dose and time dependent manner. On the other hand, human epithelial cells and fibroblasts did not show enhanced growth activities in the presence of LTA.

Animals↗

PubMed1991

Activation of mononuclear immune cells in response to staphylococcal lipoteichoic acid.

The goal of the present study was to evaluate the influence of staphylococcal lipoteichoic acid (LTA) on the activation of mononuclear immune cells. A murine tumor necrosis-like factor (TNF-like) was induced in the sera of CD-1 mice which had been primed with heat/formalin-inactivated Propionibacterium avidum KP-40 and subsequently exposed to LTA extracted from Staphylococcus saprophyticus strain S 1. Monoclonal antibody against murine TNF (anti-TNF) significantly inhibited the cytostatic activity of mice sera against transformed L-929 cells. Freshly isolated lymphocytes did not display interleukin 2 (Il-2) receptors, but receptors were expressed on Con A incubated cells and in significantly higher numbers after coexposure to staphylococcal LTA in vitro. Since the induction of TNF (macrophages) and Il-2 receptors (lymphocytes) represent stimulation of the mononuclear immune system, staphylococcal LTA may be considered to be an immunomodifier.

Animals↗

PubMed1991

Adequate function of the immune system and physiological microflora are closely correlated.

It is already known that physiological microflora of the digestive system plays an important role in local immunity. Studies on immunomodulating activity of some autoantibodies have shown that drugs affecting intestinal microflora possess potent immunosuppressive effect on systemic immunity. These observations inspired to recent investigation on the mechanisms of the influence of digestive tract bacteria on the immune system.

Animals↗

PubMed1990

[Neopterin as a marker of aspecific immunostimulation with Propionibacterium avidum KP-40 in patients with gastrointestinal tumors. A prospective randomized study].

This prospective randomized study demonstrated that a preoperative intravenous infusion of 10 mg of the bacterial preparation Propionibacterium avidum KP-40 to patients with gastrointestinal tumors significantly (P less than 0.001) enhanced the secretion of neopterin, measurable as long-lasting (greater than 16 days) elevated urine excretion. Postoperative re-infusion of P. avidum KP-40 caused (statistically significant (p less than 0.001] re-enhancement of neopterin urine levels.

Adult↗

PubMed1990

Digestive tract microflora liberates low molecular weight peptides with immunotriggering activity.

Antibiotic digestive tract decontamination in BALB/c-mice resulted in a significant reduction of peritoneal macrophage function and lymphocyte proliferation. Considerable evidence has accumulated showing that certain species of the indigenous gastrointestinal (GI)-tract microflora, e.g. Bacteroides sp., Clostridium sp., Lactobacillus sp., and Propionibacterium sp., liberate low molecular weight peptides which are able to trigger basic immune responses. Eradication of the GI-tract microflora apparently results in a lack of peptide production correlating to immunosuppression in experimental BALB/c-mice. Substitution of peptides in GI-tract decontaminated mice reconstituted macrophage function as well as proliferation of lymphatic tissue.

Animals↗

PubMed1990

Evidence for lectin-mediated adherence of S. saprophyticus and P. aeruginosa to polymers.

By hemagglutination tests surface lectins on S. saprophyticus strain S 1 with N-acetylgalactosamine (GalNac) and N-acetylglucosamine (GlcNac) specificity and on P. aeruginosa ATCC strain 27853 with N-acetylneuraminic acid (NANA) specificity could be demonstrated. To elucidate the role of bacterial surface lectins for the specific adhesion, polyether urethane discs were preincubated for 15 h at 4 degrees C in human serum or urine. Adhesion studies with S. saprophyticus S1 and P. aeruginosa ATCC 27853 onto precoated polymers revealed that microbial lectins may play a role in the colonization of prosthetic devices since lectin-blocking with competitive glycoconjugates significantly decreased bacterial adherence to the coated surfaces. Non-specific carbohydrates did not inhibit the adherence demonstrating specificity of this process.

Bacterial Adhesion↗

PubMed1990

Bacteria of human physiological microflora liberate immunomodulating peptides.

Human isolates of Propionibacterium acnes and Staphylococcus saprophyticus could be shown to liberate low molecular weight peptides (MW less than 6.500 D) with immunomodulating activity. FACS analyses of BALB/c-mouse lymphoid cells from the thymus and spleen revealed an enhanced percentage of T-helper cells after peptide administration. Intestinal microflora decontamination of BALB/c-mice considerably reduced immune cell function and lymphatic tissue proliferation. Apparently, lack of peptide production or liberation correlated to immunosuppression. Substitution of peptides (from P. acnes or S. saprophyticus) to decontaminated mice reconstituted immune cell function and proliferation. Cortisone-resistant thymocytes were used as an experimental equivalent of functional cells in the thymus. Thus, cortisone treatment of BALB/c-mice significantly reduced the number of thymocytes, however, administration of microbial peptides restored the thymus population.

Adjuvants, Immunologic↗

PubMed1990

Type of fimbriation determines adherence of Klebsiella bacteria to human epithelial cells.

Clinical isolates of three Klebsiella strains (encapsulated and nonencapsulated mutants) with type 1 (mannose-sensitive, MS+MR-), type 3 (mannose-resistant, MS-MR+) and type 1 and 3 (MS+MR+) fimbriae were investigated for their ability to adhere to epithelial cells. Considerable adhesion to human buccal, tracheal, pulmonary and uroepithelial cells could be demonstrated. Independent of encapsulation and type of epithelial cells, adhesion of MS+MR+ (type 1.3) fimbriated Klebsiella bacteria was significantly stronger than adhesion of microorganisms carrying only type 1 (MS+MR-) or type 3 (MS-MR+) fimbriate, respectively. Adherence of nonencapsulated type 1 and 3 (MS+MR+) fimbriated Klebsiella bacteria to mammalian cells was significantly inhibited in the presence of D-mannose. Certain carbohydrates (D-glucose, D-galactose) did not interfere with this adhesion process.

Bacterial Adhesion↗

PubMed1990

Effects of beta-lactam antibiotics imipenem/cilastatin and cefodizime on cellular and humoral immune responses in BALB/c-mice.

The effects of a 7-day chemotherapy with two broad-spectrum beta-lactam antibiotics (imipenem/cilastatin and cefodizime) on the humoral and cellular immune responses in BALB/c-mice were investigated. Antibiotic dosages were calculated on a body weight basis from therapeutical dosages in human medicine. Treatment of experimental mice with imipenem/cilastatin and cefodizime did not influence the production of immunoglobulines (IgM and IgG) nor the delayed type hypersensitivity to oxazolone. In vitro, exposure of human granulocytes to imipenem/cilastatin and cefodizime did not interfere with their phagocytic activity as determined by chemiluminescence assay. Subinhibitory concentrations of both antibiotics modified Staphylococcus aureus and made them more susceptible for granulocyte phagocytosis in chemiluminescence assays.

Animals↗

PubMed1990

Tetracycline and 13-cis-retinoic acid inhibit production and activity of granulocyte activating factor (GAF) from Propionibacterium acnes.

The aim of this study was to evaluate different treatment schedules on release or activity of a granulocyte activating factor (GAF) from Propionibacterium acnes. Incubation of P. acnes in physiological saline (30 min, 37 degrees C) resulted in release of a soluble factor that elicited considerable chemiluminescence response and chemotactic stimulus on human granulocytes. Pretreatment of the microorganisms with subinhibitory concentrations of tetracycline or incubation of granulocytes with 13-cis-retinoic acid significantly reduced the activating potency of GAF on these phagocytic cells. Since GAF was considered to be one of the stimuli for inflammation in acne vulgaris, administration of tetracycline and 13-cis-retinoic acid appears to be an adequate therapy.

Chemotaxis, Leukocyte↗

PubMed1990

Behaviour of lymphocyte subsets in response to immunotherapy with Propionibacterium avidum KP-40 in cancer patients.

In 15 patients the influence of unspecific immunostimulation/immunomodulation was studied. Patients constituting the therapeutical group suffered from colorectal- and gastric carcinoma, respectively, and were preoperatively treated with 10 mg whole cell preparation of immunomodulating Propionibacterium avidum KP-40. This adjuvant immunotherapy resulted in a significant increase (p less than 0.01) of the natural killer (NK)-cell population, however, total leukocyte and lymphocyte count as well as helper- and suppressor T-lymphocyte subsets did not significantly differ form control values.

Adjuvants, Immunologic↗

PubMed1990

Comparative study on the macrolides erythromycin and clarithromycin: antibacterial activity and influence on immune responses.

The in vitro activity of erythromycin and clarithromycin (a new macrolide antibiotic) on clinical bacterial isolates as well as their effects on the cellular and humoral immune responses in BALB/c-mice and on human granulocytes/monocytes was investigated. Treatment of BALB/c-mice for 7 days with these drugs did not influence the delayed type hypersensitivity to oxazolone nor the production of IgG and IgM immunoglobulins. In vitro, exposure of granulocytes to erythromycin resulted in increased phagocytosis only in higher concentrations (20 mcg/ml), whereas clarithromycin enhanced chemiluminescence response of granulocytes in concentrations ranging from 2.5-20 mcg/ml. Subinhibitory concentrations of both substances modified Staphylococcus aureus and made them more susceptible for granulocyte phagocytosis.

Animals↗