Suppression of graft-versus-host reactions by D- and L-chloramphenicol

Rapid and definitive diagnosis of infectious diseases using peripheral blood smears

A timely diagnosis is essential in the management of septicemia and septic shock. Three patients are described, all of whom presented with fever and one of whom was hypotensive at the time of admission. In each patient, rapid diagnosis of the cause of fever was possible because microorganisms were identified on a peripheral blood smear obtained at the time of admission. This identification permitted prompt initiation of appropriate antimicrobial therapy. In addition, a literature review of use of peripheral blood smears in the diagnosis of bacterial, fungal, and parasitic infections is provided.

Side effects of antibiotics on immune response parameters and their possible implications in antimicrobial chemotherapy

Antibiotics may influence immune response by quite different ways. By screening the multitude of publications on this subject, the aim of this overview was to arrive at a basic generalizing statement on the relationship between chemical structure or mode of action of antibiotics and the effect on immune response and to get an indication on whether certain in vitro and/or ex vivo parameters could represent comparable effects under clinical conditions. - The influence of antibiotics on immune response may arise by direct effects on immunocompetent cells, i.e. in the absence of microorganisms, or indirectly by changes in structure or metabolic products of germs induced by subminimal inhibitory concentrations (subMIC's). In the former case, stimulatory and inhibitory effects have been observed on phagocytosis and intracellular killing activity, on antibody production including IgE, on different parameters of cellular immunity (e.g. foodpad swelling reaction, MIF-production, mitogen/antigen induced lymphocyte proliferation and delayed type hypersensitivity skin reaction), on mediator production as interleukins or prostaglandins and the expression of corresponding receptors on immunocompetent cells as well as on the course of experimental infections with primary resistant microorganisms. - Indirect effects are related to the influence of subMIC's of antibiotics on the morphology and structure of microorganisms, on their antigenicity/immunogenicity or on their serosensitivity and enzyme and toxin production. - This overview shows that - according to the actual knowledge - antibiotics may exhibit immunological side effects which, however, can not strictly be attributed to certain chemical structures or to a certain mode of action. - It has to be considered that a literary study comparing the results of different authors is rendered difficult by the often nonhomogeneity of experimental procedures and the fact that little is known yet about immunological side effects of antibiotics in man, i.e. under clinical conditions.

Leishmania donovani: an opportunistic microbe associated with progressive disease in three immunocompromised patients

Three cases are described showing that Leishmania donovani can cause progressive disease in immunocompromised hosts. The first patient was receiving corticosteroid therapy for ulcerative colitis and the second corticosteroids and cyclophosphamide for proliferative glomerulonephritis; in the third patient, leishmaniasis occurred after a long episode of hepatosplenic schistosomiasis and salmonella bacteraemia which was treated with chloramphenicol. In two cases, the patients had moved away from areas of L donovani transmission many years before the progressive disease occurred, consistent with long-term survival of the organism in normal hosts. L donovani should be added to the growing list of opportunistic microbial infections.

Suppression of graft-versus-host reaction by preincubation of the graft with an antitumor protein, neocarzinostatin

The immunosuppressive activity of neocarzinostatin, an antitumor antibiotic with a high molecular weight, was demonstrated, as measured by the local and systemic graft-versus-host reaction in rats. The preincubation of parental strain lymphocytes with doses more than 1 micrograms/ml of neocarzinostatin for at least 10 min at 37 degrees C resulted in the marked suppression of the popliteal lymph node enlargement, when injected subcutaneously into the hind footpads of F1 hybrid rats. The suppressive effect was temperature-dependent and irreversible, because the neocarzinostatin (1 microgram/ml) pretreatment of parental lymphocytes at 4 degrees C was not effective in the suppressive activity, and the reincubation of cells after the removal of the drug from the culture did not result in demonstrable changes in the degree of suppression. The neocarzinostatin pretreatment does not result in visible changes in the oxygen consumption rate and viability of cells in vitro or in the distribution pattern within a regional lymph node, indicating that treated cells may retain the same viability and migration capacity in vivo as do untreated cells. Furthermore, the drug pretreatment resulted in the complete prevention of runting syndrome, when treated parental lymphocytes were injected intravenously into F1 hybrid rats.