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Presents information on a study which determined the temperature dependence of crystal field energy levels of cerium (Ce) ions in metals caused by the Kondo effect. Properties of Ce intermetallic compounds and alloys; Calculation of neutron quasi-elastic and inelastic scattering spectra; Dynamical susceptibility of the ion.

Conversion of Salmonella typhimurium to L-forms, both in vitro and in vivo, resulted in the expression of proteins cross-reacting to the mycobacterial 65000 MW heat-shock protein (hsp). Immunization of C3H/HeJ mice with a protective dose of stable L-form S. typhimurium induced γδ T cells in the liver, in accordance with the multiplication of L-form Salmonella in Kupffer cells. The number of γδ T cells decreased after the intracellular growth of L-form Salmonella plateaued. Persistance of the L-forms in Kupffer cells, however, allowed hepatic γδ T cells to increase within 48 hr of infection with virulent S. typhimurium. Thus, the intrahepatic colonization of L-form Salmonella seems to keep γδ T cells on standby, but the emergence of these T cells does not correlate with the expression of L-form hsp. In addition, Kupffer cells colonized by L-forms constitutively synthesized mRNA for interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α). These results suggest that conversion of S. typhimurium to L-forms in phagocytic cells builds up and maintains acquired resistance, conferred by live-cell vaccines of S. typhimurium, against murine typhoid. [ABSTRACT FROM AUTHOR]

The active component in crude ribosomal fraction (CRF) of Salmonella typhimurium, capable of inducing protective antibody, was partially purified by two series of chromatography (Sephadex 0-150 and DEAF-Sepharose CL6B) after sodium dodecyl sulphate (SDS)-treated CRF was precipitated with ammonium sulphate. The major active component was eluted by 0.4-045 M NaCl from DEAE-Sepharose CL6B, and its molecular weight was 43,000 as determined by SDS-polyacrylamide gel electrophoresis. Immunization with the fraction containing 43,000 component alone did not always confer protection on CFI mice, but its administration together with either the purified transfer RNA (tRNA) or Freund's complete adjuvant (FCA) was much more effective against infection with S. typhimurium. Antibody to the fraction containing 43,000 component was not only free in serum but also associated with peritoneal cells. Macrophages that had been exposed to the antibody had enhanced anti-bacterial activity. Western blot analysis showed that 43,000 component did not react to antiserum to lipopolysaccharide (LPS), but to antiserum to CRF. The antibody elicited by non-O antigenic component and the cell-mediated resistance stimulated by the adjuvant effect of RNA together confer effective protection on CFI mice. [ABSTRACT FROM AUTHOR]

Two outbred mouse strains, ddY and CF1, were tested for their ability to be protected against infection with Salmonella typhimurium by several types of salmonella vaccines. These strains have the same levels of innate susceptibility to S. typhimurium, and also have the same capacity to develop delayed-type hypersensitivity (DTH) to salmonella antigens. Both the crude ribosomal fraction (CRF) and live-cell vaccines conferred acquired resistance on both strains, characterized by greater responses of T cells to salmonella antigens. Mice of the ddY strain were also protected by the purified transfer RNA (tRNA) vaccine, which was free of O antigens, but CF1 mice were not, despite the presence of T-cell reactivity with salmonella antigens. Neither strain was protected by the phenol--water-extracted lipopolysaccharide (LPS). The tRNA-immunized CF1 mice were protected by transfer of antiserum to CRF, but not by transfer of anti-LPS antibody. This antiserum to CRF. however, did not transfer acquired resistance into non-immune mice of either strain. These observations suggest that CF1 mice may require an antibody to another non-O antigen existing in CRF to develop acquired resistance, and that stimulation of the defence system by tRNA may be essential to the development of acquired resistance in CF1 mice. [ABSTRACT FROM AUTHOR]

In order to compare the potential of salmonella vaccines prepared from Salmonella zyphimurium to provide the longer-lasting protection from the aspects of cell-mediated immunity, groups of mice were immunized with optimal doses of the following preparations: live cells, ribosome-rich extract, acetone-killed cells, and heat-killed cells. At various intervals post-immunization, mouse peritoneal macrophages and splenic I cells were tested for biological activities. The capacity of each vaccine to confer mouse protection against a lethal challenge with S. typhimurium correlated with the degree of macrophage activation engendered by each of them in the early stage of immunization. In the late stage of immunization, the level of mouse protection conferred by each vaccine was found to be based on the capacity of T cells to respond to salmonella antigens, which correlated with the degree of adoptive immunity by T cells. The live-cell and ribosomal vaccines were superior to killed-cell vaccines in inducing the cell-mediated protection. Thus, the longer-lasting immunity provided by the live-cell and ribosomal vaccines can be accounted for by the fact that T cells of mice immunized with both vaccines have the persistent reactivity to salmonella antigens. [ABSTRACT FROM AUTHOR]

Transfer ribonucleic acid (tRNA) was isolated from a two-heptose mutant of Salmonella typhimurium LT2 (strain SL1004) and was found to afford 100% mouse protection against challenge with 1000 LD50 of strain LT2. The intraperitoneal minimum effective dose of tRNA was 5μg RNA per mouse and this dose was significantly lower than that of ribosomal RNA for ddY mouse strain. The protective immunity was independent of the presence of antibodies to cell-surface antigens, and was transferred mainly by T cells. The protective moiety of tRNA was sensitive to ribonuclease digestion which resulted in 85% reduction in the mouse survival rate, but was completely resistant to protease digestion. The present study demonstrates that the immunogenic activity of salmonella RNA is present in both ribosomal RNA and tRNA. [ABSTRACT FROM AUTHOR]

Intravaginal inoculation of approximately 10(6) piliated gonococci into female mice at different stages of the estrous cycle without any antibiotic pretreatment resulted in gonococcal endometritis. The percentage of mice with positive cultures for Neisseria gonorrhoeae one week after challenge was at least 80%, regardless of at which estrous stage the mice were inoculated. Recovery of gonococci from the uterus continued for more than one month, and the recovery rate appeared to depend on the estrous stage at inoculation. Serum levels of antibodies to crude outer membrane complex began rising one week after inoculation with gonococci and reached a maximum three week after challenge. This animal model is proposed for the study of gonococcal genital infection. [ABSTRACT FROM AUTHOR]

The anti-inflammatory effect of erythromycin was investigated using zymosan-induced peritonitis in mice. When mice were given erythromycin 10 mg/kg/day po for 28 days, a marked suppression of inflammatory responses, including the reduced influx of leucocytes, plasma exudation and prostaglandin E2 synthesis, was observed. However, neither a 7-day treatment with erythromycin nor a 28-day treatment with clindamycin suppressed the response. The anti-inflammatory activity induced after a 28-day treatment with erythromycin was comparable to the anti-inflammatory effect conferred by a 2-day treatment with dexamethasone 40 microgram/mouse/day. Thus, these data confirm previous studies which show that erythromycin can exert an anti-inflammatory effect when used over long periods of time. [ABSTRACT FROM AUTHOR]

The effects of erythromycin stearate over a concentration range of 0.1-10 mg/l on production of elastase, protease and leucocidin by clinical isolates of Pseudomonas aeruginosa were investigated. Growth of P. aeruginosa N42 in broth was not affected significantly during 24 h culture with erythromycin (0.1-10 mg/l), although extracellular protein contents were reduced by erythromycin at concentrations of 0.1-1.0 mg/l. Production of elastase and protease by strain N42 was significantly suppressed by erythromycin with a maximum inhibition at 0.5 mg/l, but the complete inhibition of enzyme production was not achieved. In contrast, leucocidin production by strain N42 was completely impaired by erythromycin at concentrations of 0.1-5.0 mg/l. Although the leucotoxic activity, as determined by vital staining, was not detected, the leucocidin fraction prepared from the autolysate of strain N42 cultured with 10 mg/l of erythromycin induced morphological changes in human leucocytes, resulting in release of elastase. Erythromycin exerted similar effects on other clinical isolates of P. aeruginosa. These findings indicate that erythromycin might have a role in P. aeruginosa infection, although it has no direct antibacterial activity. [ABSTRACT FROM AUTHOR]