IgM accelerates affinity maturation.

Secreted IgM is a potent adjuvant that concentrates antigen into secondary lymphoid organs and initiates antibody responses, germinal centre formation and is crucial in resolving infections. The current studies investigated the influence of specific IgM on both the quantity and quality of antibody produced in response to T-dependent and T-independent antigens. The addition of IgM to either antigen had no significant effect on the titre or duration of antibody responses. However, the presence of specific IgM led to accelerated affinity maturation when mice were challenged with low doses of IgM-containing immune complexes (IgM-IC) of T-dependent antigens compared with antigen alone. Interestingly, the administration of higher concentrations of IgM-IC increased follicular deposition of antigen but did not result in accelerated affinity maturation or in higher antibody affinities. The administration of IgM complexed with T-independent antigens had no effect on antibody titre, duration or affinity maturation, despite increased antigen deposition in lymphoid follicles. Together, these results demonstrate that IgM accelerates affinity maturation in immune responses to T-dependent antigens and implies an antigen optimum exists for the generation of high affinity antibodies. The data also suggest IgM plays an important role in the induction of CD4 T cells, facilitating germinal centre formation and function.

Preventing and reducing substance use among institutionalized adolescents.

The Residential Student Assistance Program, serving high-risk, multiproblem, inner-city, primarily African-American and Latino youth, was evaluated for its ability to prevent and decrease alcohol and other drug use. Participants were drawn from several adolescent residential facilities: three foster care sites for abused, neglected, orphaned, or troubled adolescents, a nonsecure facility for adjudicated juvenile offenders, a treatment center for teens with severe psychiatric problems, and a locked county correctional facility. In addition, comparison groups were employed. A 5th-year outcome evaluation documented the program's effectiveness in both preventing and reducing substance use among participants, with impact related to program dosage. Qualitative process data clarified and strengthened confidence in the quantitative outcomes.

Overview--Air Force policy on halons.

Halons have been used for decades by the Air Force for a variety of fire protection applications. Their unique combination of effectiveness, low toxicity, ease of use, cleanliness, and low manufacturing cost appear to make them ideal for many situations. Unfortunately, they also deplete the earth's protective ozone layer and, consequently, their production is being phased out globally under the Montreal Protocol. United States legislation implementing the terms of the Protocol required an end to production of ozone depleting chemicals (ODCs) by the year 2000. In November 1991, the Air Force issued a policy requiring an end to ODC purchases by the end of 1997. In February 1992, President Bush announced an even more accelerated phaseout to 1995. The Montreal Protocol is expected to be amended to reflect the more aggressive US phaseout date. This accelerated date increases the urgency of the Air Force's search for ODC alternatives, especially for mission critical uses for which no alternatives have yet been identified. The search is complicated by the fact that the requirements an alternative must meet are unique to their specific application. This paper will provide an overview of the most important Air Force halon uses and review Air Force strategies for ensuring mission continuity until alternatives can be developed.

Daily marijuana use and problem behaviors among adolescents.

Previous research by Johnston has shown that high school seniors who are daily marijuana users are distinct from the larger population of seniors in a variety of ways. This paper focuses on adolescent daily marijuana users. It replicates Johnston's work and also qualifies it in an important way. We find that level of marijuana use does not make a significant independent contribution to school problems when such critical factors as lifetime cigarette smoking, lifetime multiple drug use, whether respondent has ever used an illicit drug, rebelliousness, and gender, are taken into account. It is concluded that use of marijuana is only one element in a large and complex picture of interrelated problems and behaviors.

Working in the schools with children of alcoholic parents.

Despite evidence that parental alcoholism has a serious effect on children, few resources are available to help children of alcoholic parents cope with their feelings. The author suggests that the school is the logical place to provide services, describes characteristics common to most of these children, and discusses ways in which school social workers can intervene.