Interferon production in mice by the capsular polysaccharide of Klebsiella pneumoniae

The capsular polysaccharide of Klebsiella pneumoniae (CPS-K) type 1, Kasuya strain, induces interferon production in the blood of mice when injected intravenously. CPS-K resembles bacterial endotoxin (lipopolysaccharide) in the time pattern of interferon production, with peak levels 2h after injection. CPS-K on a weight basis exhibits a more potent interferon-inducing effect than lipopolysaccharide. The active substance responsible for the interferon-inducing activity of CPS-K is the neutral CPS-K antigen which is antigenically distinct from the O antigen and from acidic CPS-K (the type-specific capsular antigen). Neutral CPS-K from the Kasuya strain has been already found to exhibit a strong adjuvant effect on antibody responses to various antigens in mice. Preparations of neutral CPS-K from other strains of K. pneumoniae, of which adjuvant action is only very weak, exhibit interferon-inducing activity similar to the preparation from the Kasuya strain. Heterologous and homologous tolerance to re-induction of interferon is produced by a prior injection (one each) of LPS, neutral CPS-K, and acidic CPS-K. No simple correlation exists between the inducing and tolerogenic capabilities of these substances.

A histochemical study on the central effect of monoamine precursors

A histochemical investigation has been made on the central monoamine neurons after the administration of monoamine precursors and peripheral decarboxylase inhibitor in experimental animals and the results are summarized as below: (1) Catecholamine fluorescence in the brain reduces and yellowish indoleamine fluorescence manifests after the treatment with 5HTP alone and Ro4-4602 plus 5HTP. These findings support the view that catecholamine is likely to be replaced by indoleamine. (2) Ro4-4602 does not cause directly any change in central catecholamine neurons except in median eminence where the inhibitor causes a decrease in dopamine fluorescence. The findings indicate that the inhibitor may act in the hypothalamus as same manner as in the peripheries, because the hypothalamus is presumably lacking of blood brain barrier. (3) L-Dopa alone and L-Dopa plus Ro4-4602 enhance dopamine fluorescence in the substantia nigra and the median eminence, especially an increase in the extra-neuronal fluorescence can be seen in the latter. This indicates the releasing of amines from cell body into extraneuronal spaces.

Quantitation of bidirectional shunt from a single dye-dilution curve

A method for quantitating intracardiac bidirectional shunt and estimating its blood flow is presented. Three curves, defined as "right-to-left shunt curve", "normal pathway curve", and "left-to-right shunt curve" were separately drawn from the original downstream dye-dilution curve, and their areas ?A'', A, A', respectively, were calculated in the conventional manner. A'/A showed left-to-right shunt ratio (QL-R%) even in the presence of right-to-left shunt. However, right-to-left shunt ratio (QR-L%) was given by (1-A'/A)/(A/A'' + 1--A'/A), and equalled A''/(A + A'') only when left-to-right shunt was absent (A' equals O). A''/(A + A) should become increasingly higher than QR-L% with rise in QL-R% (equals A'/A). The relationship between A''/(A + A'') and QR-L% for various A/A isopleths is shown by figure. A good agreement (r equals 0.848, p less than 0.001) was found between QL-R% values by the present method and those calculated by the oxygen method. In contrast, QR-L% values by the present method were consistently lower than those by the oxygen method; the difference was exaggerated especially in cases with history of cardiac failure, and these cases tended to show lower systemic flow. The average difference in QR-L% between the two methods, found in cases free from failure, was 7 per cent. This was thought to be ascribed to intrapulmonary physiological shunt.

Comparative studies on 5,5'-dithiobis-(2-nitrobenzioc acid)-treated myosins

Myosins prepared from chicken and rabbit fast and slow muscles were treated with 5,5'-dithiobis-(2-nitrobenzoic acid) (Nbs2). About half of the thiol groups of the fast muslce myosins reacted with Nbs 2, but in slow muscle myosins, only about 10-20% of the thiol groups reacted. This treatment removed 50-60% of the L2 components, Nbs2 light chain, from fast muscle myosins, but did not result in specific dissociation of the light chains in slow myscle myosins. The treatment sometimes released L4 component from chicken muscle myosins instead of L2 component. The changes of myosin ATPase [EC 3.6.1.3] activities caused by this treatment did not correlate with the release of Nbs2 light chain, but were dependent upon the species, chicken or rabbit.

Factors affecting experimental infection with Cryptococcus neoformans in mice with special reference to an endotoxic substance of C. neoformans

A close correlation was observed between body weight and length of the survival time of mice inoculated intravenously (i.v.) with Cryptococcus neoformans (p less than 0.001). An endotoxic substance of C. neoformans (Cr-ET) increased the susceptibility of mice to i.v. infection of C. neoformans only when more than 50 mug of Cr-ET was injected i.v. 24 hours before infection. Intraperitoneal (i.p.) administration of dimethyl sulfoxide which is found to enhance bacterial infection did not enhance death rate of mice infected i.p. with C. neoformans.

Microbial adjuvant and autoimmunity. I. Induction of antibody responses to syngeneic tissue extracts in mice treated with capsular polysaccharide of Klebsiella pneumoniae

With the use of the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) as a powerful adjuvant, high precipitin responses could be induced in mice to syngeneic eyeball extracts and thyroid gland extracts which were normally nonimmunogenic. Only very weak responses were induced to eyeball extracts by Freund's complete adjuvant. Repeated administrations of the antigens mixed with CPS-K at time intervals of 30 days (more than twice for the eyeballs or more than three times for the thyroid glands) were required for induction of high precipitin responses. Antibody responses detectable by the immunofluorescent technique could be induced to syngeneic lymphoid tissue extracts by injecting the mixture of antigen and CPS-K more than five times at time intervals of 30 days. These findings suggest that repeated stimulation by autoantigens together with such a strong adjuvant as CPS-K can terminate natural tolerance against autoantigens.

Non-specific stimulation of immunoglobulin synthesis in mice by capsular polysaccharide of Klebsiella pneumoniae

Intramuscular injection of a non-immunogenic dose (1 mg) of the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) into mice caused a marked and prolonged increase in the amount of the serum IgM and IgG. The increase of IgM after this injection was over 100 times greater than that of antigen-specific IgM antibodies produced by injection of an immunogenic dose of CPS-K (5 μg) or sheep red blood cells (SRBC) (2 X 10⁸). The increase in the amount of immunoglobulins was not related to induction of immunological paralysis to the major subcomponent of CPS-K (acidic CPS-K) by a large dose of antigen, but was induced by non-antigenic stimulation by the minor subcomponent of CPS-K (neutral CPS-K), which was non-immunogenic at any dose. In mice injected with a non-immunogenic dose of CPS-K, antibody levels in the serum to three kinds of non-cross-reacting antigens, SRBC, bovine serum albumin (BSA) and a possibly autochthonous IgG (IgM—IgG mixed type cryoglobulin) were also increased. The number of plaque-forming cells (PFC) for SRBC in the spleens of mice was also markedly increased after CPS-K injection. These antibodies to SRBC and BSA and PFC for SRBC were exclusively of IgM type and increased to as high levels as those found after specific antigenic stimulation. This marked increase in IgM antibody was neither followed by an increase in IgG antibody nor by immunological memory for a secondary IgG response.

The effect of antigen doses and time intervals between antigen injections on secondary, tertiary and quaternary antibody responses. Establishment of hyperimmunization with bovine serum albumin in mice treated with capsular polysaccharide of Klebsiella pneumoniae

Injection of bovine serum albumin (BSA) with the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) as adjuvant strongly primes mice for booster injections of BSA alone. The best doses of antigen for booster injections varied according to the frequency of antigen injections and the time interval between antigen injections. Increase in memory following the injection of BSA mixed with CPS-K adjuvant was first detected 10 days later. Memory continued to increase as the time interval after priming was increased to 90 days. Memory for the tertiary response increased after the optimum secondary antigenic stimulus. Increase in memory after the secondary antigenic stimulus was detected as early as 7 days after injection. Even secondary injection of the high dose of 50 mg of BSA did not exhaust immunological memory. Memory was also increased after the tertiary antigenic stimulus. Extremely high antibody responses (up to 49.2 mg protein per ml of antibody) could be obtained by eliciting tertiary and quaternary antibody responses optimally at the time memory was developed to the maximum level.