Possible role of sialic acid and endogenous neuraminidase in T-cell proliferation.

The proliferation of T cells in MLR with strains C57Bl/6 and DBA2, mouse spleen and lymph node cells was increased when the inhibitors of endogenous neuraminidase was added in the culture. This is in favor of participation of this enzyme and implicitly of terminal sialic acid in the proliferation of T-cells. Ths possibility that the suppressive activity of T-cells might have been abolished is discussed.

Contribution to the Study of Plectranthus fruticosus Leaf Essential Oil.

The essential oil of PLECTRANTHUS FRUTICOSUS L'Hérit. (Labiatae) is shown to contain at least fifty components, among which the major one, i.e. sabinyl acetate, accounts for more than 60% of the total. To our knowledge, this compound is described in Labiatae at such a high concentration for the first time. A preliminary study on rats reveals that this essential oil is teratogenic and/or highly foetotoxic.

Immunoglobulin Gm and Km genetic markers in Vietnamese.

The distribution of the G1m (1,2,3,17), G2m(23), G3m(5,10,11,13,14,15,21,28) and Km (1,2) allotypic markers has been examined in 122 unrelated Vietnamese subjects originating from all regions of Vietnam. The 13 observed phenotypes have been explained by means of 8 haplotypes: 5 'major' ones (which are also known to be usual in all other reported Mongoloid populations) and 3 'minor' ones. Consideration of gene frequencies allows easy integration of Vietnamese within the south-north cline of Gm haplotype distribution in East Asia, where they insert between Southern Chinese, on one hand, and Singapore as well as South Central Chinese on the other hand. The observed Km10.290 frequency value revealed to be of the same order of magnitude as the values reported for most other non-Thai Mongoloids.

The variable region of human immunoglobulins. I. Serologic and structural correlations of antigenic markers common to V lambda I and V lambda IV proteins (isotypic cross-reactivities).

Sixty-eight human lambda-chain sources including representatives of the five different subgroups were studied for the distribution of the serologic markers ST, 111, and VOR The variable region character of these antigenic determinants has been demonstrated for those proteins whose primary structures had been partially or completely determined previously. The lambda-chain sub-groups I and IV are readily distinguished antigenically but the specificity designated VOR is shared between them and is absent in the II, III, and V subtypes. The results of these studies are discussed with respect to the possible relationships of the structural genes controlling the synthesis of the lambda-chain subgroups, and some potential phylogenetic and functional meaning of the heterogeneities is revealed.