[Animal experiment studies on the modification of the immune system by ofloxacin]

Effects of cefodizime and cefotaxime on cellular and humoral immune responses

Cefodizime is a new cephalosporin antibiotic which has shown some remarkable immunomodulating activities. To mimic possible immunopharmacological effects of prolonged chemotherapy in vivo, we investigated the influence of a seven-day treatment with cefodizime on cellular and humoral parameters of the immune system in BALB/c mice. The dosages (0.4, 0.8 and 1.8 mg cefodizime per day) were calculated on a per kg bodyweight basis according to therapy recommendations for humans. Delayed type hypersensitivity (oxazolone test) as well as the production of IgM and IgG antibodies (direct and indirect plaque forming test) were investigated in BALB/c mice. Leukocyte and monocyte activities were measured using human cells. The results are discussed using cefotaxime as comparable reference drug.

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.

Chemiluminescence response of human polymorphonuclear and mononuclear phagocytic cells induced by Staphylococcus saprophyticus, lectinophagocytosis versus opsonophagocytosis

Two strains of Staphylococcus saprophyticus with well characterized cell surface structures were studied to determine the contribution of lectinophagocytosis versus opsonophagocytosis exerted by human phagocytic cells from five healthy donors. The luminol specific chemiluminescence assay was used to evaluate the response of phagocytes. Human polymorphonuclear leukocytes (PMNL) were demonstrated to have surface lectin receptors, since the chemiluminescence response towards both S. saprophyticus strains was inhibited by lectin-specific glycoconjugates for those organisms. Phagocytosis of S. saprophyticus by mononuclear cells was not inhibited by microbial lectin-specific glycoconjugates but was inhibited by D-mannose, suggesting that human monocytes express D-mannose specific lectins on their surface.

Granulocyte activation by a cell surface complex of Staphylococcus saprophyticus: a receptor-mediated phenomenon

High molecular weight cell surface complex (CSC) from Staphylococcus saprophyticus strain S 1 could be shown to be a potent stimulator of human polymorphonuclear leukocyte (PMN) chemiluminescence whereas human monocytes were not activated. Heating of the CSC (100 degrees C for 5 min) as well as protease treatment significantly (p less than 0.001) inhibited the PMN activating process suggesting that the protein part of the molecule mediates its biological activity. Data on the biochemical character of the CSC are given. Preincubation of PMNs with CSC inhibited another chemiluminescence response to this substance and to homologous opsonized S. saprophyticus, respectively. However, restimulation with formylmethionyl peptides (fMLP) or non-opsonized staphylococci suggested that the PMN function is a receptor-mediated phenomenon. These data were substantiated since fMLP activated PMNs could be evidently re-stimulated with CSC but not with analogue peptides. Evaluation of the bactericidal capacity of human PMNs yielded comparable results.

Granulocyte activating factor released from Propionibacterium acnes. A possible mediator of inflammation in acne vulgaris

Incubation of Propionibacterium acnes but not of Propionibacterium granulosum or Propionibacterium avidum (for 30 min at 37 degrees C in physiological saline) released a soluble factor that produced enhanced chemiluminescence response of human granulocytes as well as increased chemotactic motility of these cells. Sephadex G-25 filtration of the granulocyte activating factor (GAF) revealed its low molecular weight and apparent peptide character. Thus, GAF may be a stimulus for inflammation in acne vulgaris since low molecular weight chemotactic factors can be expected to penetrate follicular walls.

Lectin-mediated cell-attachment and phagocytosis of Staphylococcus saprophyticus strain S1

Adhesion studies with cryotome sections of human kidney and lung respectively uroepithelial cells together with blocking experiments with competitive carbohydrates suggested that specific attachment of S. saprophyticus strain S 1 to host cells apparently is mediated by lectins. Accordingly, microbial lectin blocking with specific glycoconjugates or lectin dysfunction (after treatment of bacteria with subinhibitory concentrations of tunicamycin) significantly decreased staphylococcal adherence to epithelial cells. Chemiluminescence measurements of human polymorphonuclear leukocyte (PMN) function yielded results suggesting importance of lectin-receptor interaction in phagocytosis, too, since PMN activity was significantly decreased after staphylococcal lectin blocking or dysfunction.

Studies on a biological response modifying LYSAT from Propionibacterium avidum KP 40

Propionibacterium avidum KP 40 cells were mechanically disintegrated in order to obtain the soluble immunostimulatory (antineoplastic) LYSAT. Chemiluminescence measurements of human leukocyte function yielded enhanced activation of the cells after incubation with 2.5 and 5 mg of LYSAT. As compared to non-treated controls, administration of LYSAT to BALB/c-mice (1, 2.5 and 5 mg; intraperitoneally, subcutaneously, intranasal; 7, 4 and 2 days prior to challenge) induced a significant enlargement of the spleen as well as significantly reduced sarcoma L-1 lung colonization 14 days after challenge and evidently enhanced chemiluminescence response of peritoneal macrophages.

The role of staphylococcal lectins in human granulocyte stimulation

The anti-staphylococcal activity spectrum of human polymorphonuclear leucocytes (PMN) is widely ranged. Using chemiluminescence measurements, the opsonin-independent stimulation of PMNs from eight healthy humans towards two Staphylococcus saprophyticus strains (S 1 and S 35) was investigated. Strain S 1 was shown to have surface lectins with N-acetylgalactosamine specificity, whereas strain S 35 had N-acetyl-neuraminic acid specificity. Three different PMN-reaction patterns could be demonstrated: PMN stimulation was either sensitive to N-acetylgalactosamine-or N-acetylneuraminic acid-blocking, or resistant to both. These results point to the importance of lectins for staphylococcal-PMN interactions.

Modification of glycosylation by tunicamycin treatment inhibits lectin-mediated adhesion of Streptococcus pneumoniae to various tissues

Oligosaccharide moieties of cell surface glycoconjugates are thought to be involved in recognition events associated with infectious diseases. Treatment of Streptococcus pneumoniae (which exhibits well defined surface lectins) with subinhibitory concentrations of the antibiotic tunicamycin was found to block the protein glycosylation of the bacterial surfaces. Since bacterial lectins (adhesins) are in most cases glycoproteins and play an important role in the organ specificity of infectious diseases, adhesion of Streptococcus pneumoniae to frozen sections of lung, meninges and kidney (from Balb/c-mice) was almost totally lacking after inhibition of the biosynthesis of N-linked carbohydrate chains which are important for an adequate lectin function. Chemiluminescence measurements of human granulocyte stimulation yielded results suggesting a great importance of lectin-carbohydrate interactions in this process, too. These experimental data indicate that the presence of specific cell surface carbohydrates is required for a successful completion of the adhesion phase of pathogenic bacteria in infectious diseases and for the induction of granulocyte stimulation.

Cell surface antigen of encapsulated Staphylococcus epidermidis ATCC 31432

The cell surface antigen (CSA) from encapsulated Staphylococcus epidermidis ATCC 31432 was isolated and fractionated by DEAE-Sephadex ion-exchange chromatography. It yielded a single precipitin line against rabbit antiserum and was composed of galactose, glucosamine, and two (so far) unidentified carbohydrates linked to a protein backbone. Glycerol could not be detected. In an experimental mouse infection, CSA showed some protective activities, enhancing the stimulation of granulocytes as well as the immunoglobulin M response. Apparently, CSA is different from teichoic acid.

Ofloxacin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use

Ofloxacin is one of a new generation of fluorinated quinolones structurally related to nalidixic acid. It is an orally administered broad spectrum antibacterial drug active against most Gram-negative bacteria, many Gram-positive bacteria and some anaerobes. Ciprofloxacin is the only other quinolone with superior in vitro antibacterial activity. However, the pharmacokinetic profile of ofloxacin is superior to that of ciprofloxacin, with more rapid absorption and a peak serum concentration several times higher. Moreover, ofloxacin achieves high concentrations in most tissues and body fluids. The results of clinical trials with ofloxacin have confirmed the potential for use in a wide range of infections, which was indicated by its in vitro antibacterial and pharmacokinetic profiles. It has proven effective against a high percentage of infections caused by Gram-negative organisms, slightly less effective against Gram-positive infections, and effective against some anaerobic infections. Clinical efficacy has also been confirmed in a variety of systemic infections as well as in acute and chronic urinary tract infections, and ofloxacin has generally appeared to be at least as effective as alternative orally administered antibacterial drugs. Ofloxacin is well tolerated and, although experience with the drug in clinical practice to date is limited, bacterial resistance does not appear to develop readily. Thus, ofloxacin is an orally active drug which offers a valuable alternative to other broad spectrum antibacterial drugs.

Effects of ciprofloxacin on the humoral and cellular immune responses in Balb/c-mice

The effects of a 7 days chemotherapy with ciprofloxacin on the humoral and cellular immune responses in Balb/c-mice were examined. Ciprofloxacin-doses used were calculated on a body weight basis from therapeutic dosages in humans. In a dose-dependent way IgM as well as IgG responses were significantly increased. The delayed-type hypersensitivity reaction to oxazolone was not significantly changed. In in vivo as well in vitro experiments ciprofloxacin showed no modulatory activity on the concanavalin A and LPS-induced proliferative activities of mouse spleen cells.