Treatment with nontoxic monophosphoryl lipid A (MPL), which was derived from a polysaccharidedeficient, heptoseless Re mutant of Salmonella typhimurium, was found to inactivate suppressor T-cell activity, as evidenced by a decrease in the degree of low-dose immunological paralysis expressed and an increase in the magnitude of the antibody response to type III pneumococcal polysaccharide. The effects produced, which could not be attributed to the polyclonal activation of immune B cells by MPL, were dependent upon the dose of MPL used, as well as the time when MPL was given relative to low-dose priming or immunization with type III pneumococcal polysaccharide. Neither amplifier nor helper T-cell activity was decreased by treatment with the same, or larger, doses of MPL. The significance of these findings to the use of MPL as an immunological adjuvant or an immunomodulating agent is discussed.

BALB/c mice immunized with bacterial levan (BL) produce an immune response that fails to generate antibody expressing the idiotype (Id) of the beta (2 leads to 6) fructosan-binding myeloma protein ABPC 48 (A48). Pretreatment of newborn BALB/c mice (at 1 d of age) with 0.01-10 microgram of affinity purified BALB/c anti-A48 Id antibody followed by immunization with BL 1-2 mo later produces an anti-BL response that expresses the A48 Id. This shows that A48 Id+ anti-BL clones belong to a normally silent fraction of the anti-BL repertoire. The activation of A48 Id+ anti-BL clones anti-A48 Id antibody is specific because the pretreatment of newborn mice with anti-MOPC 384 Id antibody, followed by immunization with BL, does not lead to its activation. Moreover, pretreatment of mice with anti-A48 Id antibody does not alter the MOPC 460 Id+ component of the anti-TNP response. It is also important to note that the activation of the A48 Id+ clone in pretreated mice requires subsequent immunization with BL.

Treatment with nontoxic monophosphoryl lipid A increased the magnitude of the immunoglobulin M (IgM) antibody response to type III pneumococcal polysaccharide in young (2to 4-week-old) mice. This was accompanied by the appearance of significant numbers of IgGland IgG3secreting antibody-forming cells in 4-week-old mice. These findings indicate that monophosphoryl lipid A can be used as an adjuvant to improve the immunogenicity of poorly immunogenic antigens in young, immunologically immature animals.

Processes of expansion in central and eastern Africa, independently evidenced by linguistics, anthropobiology and archaeology, display such similar patterns that they may be regarded as facets of the same sequence of events. This paper develops mainly the anthropobiological evidence by using new methods of analysis based on multivariate distances. It ends with a coherent synthesis of the contributions of the three disciplines to the problems of Bantu expansion.

A large set of measurements were taken on 512 women and 425 men belonging to ten populations of the Niger bend area, some of which live in the Sahelian, the other in the Sudanian climatic zones about 200 km apart. The two zones differ chiefly by a two-fold higher annual rainfall in the Sudanian zone. The pattern of differences in body weight, skinfold and limb circumferences suggests that the Sahelians allot proportionally more food and/or less physical work to women than the Sudanians . In one or both sexes, Sahelians have significantly longer lower limbs and forearms, larger hands and ears, a narrower face, and a higher and narrower nose. Sexual dimorphism of the shoulder-hip-width proportions is lower in the Sahelians , resulting from the Sahelian males, but not females, having wider hips, whereas Sahelians of both sexes have narrower shoulders. Multivariate analysis using D2 distances shows Sahelian and Sudanian populations forming two separate clusters, with the exception of the Dogon . In the male sex, nose width and sitting height account for the total multivariate interpopulational variation; nose width alone separates the two zonal groups, again with the Dogon as an exception. The position of the Dogon near to Sudanian populations while living in the Sahelian zone is explained by their migration from the Sudanian zone a few centuries ago. Adaptative genetic response to climate is proposed as a partial explanation of the evidence presented.