Circulating immune complexes in the serum of diabetes mellitus in childhood by a modified 125I-C1q binding test.

The 125I-C1q binding test for the detection of soluble immune complexes in native unheated human serum was applied to the study of sera from 52 patients with diabetes mellitus in childhood. This radiolabeled C1q binding test is more sensitive and reproducible among the various methods proposed for the detection of immune complexes. The 125I-C1q binding activity in 52 sera from diabetes mellitus in childhood was 9.47 +/- 0.36% compared to 6.94 +/- 0.74% in normal controls. 125I-C1q binding values in diabetes mellitus in childhood were significantly higher than normal controls. Slight high values were seen in 3 patients with positive anti-DNA-antibodies in diabetes mellitus in childhood. 125I-C1q binding was not significantly increased in patients with positive antithyroid antibodies and insulin antibodies. There was no significant correlation between the duration of diabetes and 125I-C1q binding activity.     

Aggregation pattern of individuals and the outcomes of competition within and between species: Differential equation models

The influence of spatial distribution pattern on the outcomes of intra- and interspecific competition is studied theoretically. The models developed are the generalized logistic andVolterra equations, whereLloyd 's indices of intra- and interspecies mean crowding were incorporated with their assumed linear relationship to mean density in order to express the intensity of crowding which is really effective to the existing individuals. It is shown that while the increasing patchiness of distribution has a pronounced effect of promoting the intraspecific competition and lowering the equilibrium density for individual populations, it generally relaxes the interspecific competition, making it easy for different species sharing the same niche, which would otherwise be incompatible, to coexist stably. These models thus provide a simplest theoretical basis to explain why many insect populations in nature are kept relatively rare in number and why a number of allied species often coexist freely sharing the same resource, against the “competitive exclusion principle” deduced from the originalVolterra equations.     

Adjuvant activity of Klebsiella O3 lipopolysaccharide: no contribution of proteins to the expression of adjuvant activity

Previously we found that Klebsiella O3 lipopolysaccharide (KO3 LPS) isolated from culture supernatant of strain Kasuya (O3: K1) or its decapsulated mutant strain LEN-1 (O3: K1-) exhibited very strong adjuvant activity in augmenting antibody response and delayed-type hypersensitivity to protein antigens in mice. The preparation of KO3 LPS after deproteinization by four cycles of treatment with chloroform-butanol (5: 1) usually contained a small percentage of proteins and a definite amount of another antigen which was destroyed by heating at 100 C for 1 hr. This antigen proved to be derived from type 1 fimbriae which are responsible for mannose-sensitive hemagglutination of guinea pig erythrocytes. The preparation of KO3 LPS isolated from culture supernatant of the strains which did not produce type 1 fimbriae exhibited strong adjuvant activity similar to that of the preparation from those which produced them. The preparation of KO3 LPS treated with hot phenol water which is known to remove lipid A-associated proteins exhibited a similar strong adjuvant activity. The preparation of KO3 LPS after extensive deproteinizing, two cycles of pronase treatment followed by ten cycles of treatment with chloroform-butanol, no longer contained detectable amounts of proteins and the fimbrial antigen, but this preparation also exhibited similar strong adjuvant activity. Moreover, there was no difference in strength of the adjuvant activity between the preparation of KO3 LPS isolated from culture supernatant and that isolated by the phenol method from bacterial cells. The present study demonstrates that the strong adjuvant activity of the preparation of KO3 LPS does not depend in any way on proteins contaminating the preparation.     

Mast cell degranulating (MCD) peptide and its optical isomer activate GTP binding protein in rat mast cells

The MCD peptide in bee venom induces degranulation in mast cells. The internal calcium concentration of mast cells increased and remained high following MCD stimulation. This calcium increase was blocked by pertussis toxin (Ptx) treatment, suggesting that MCD peptide activates Ptx-sensitive G-protein. Even in the absence of external calcium in the incubation medium, the calcium concentration increased by MCD treatment, but soon returned to the original level. D-MCD, the optical isomer of the MCD peptide, also increased the internal calcium concentration through a Ptx-sensitive pathway. We suggest that cationic clusters at one side of the surface are more important in activating the G-protein than the alpha-helix conformation.