The lymphokine "inhibitor of DNA synthesis" (IDS) suppresses human T lymphocyte proliferation by an interleukin-2-independent mechanism.

IDS is a soluble glycoprotein product of activated T cells that inhibits lymphocyte proliferation induced by antigens and by lectin mitogens. This immunosuppressive lymphokine has been distinguished from lymphotoxin, Proliferation Inhibitory Factor, Colony Inhibitory Factor, Macrophage Inhibitory Factor, and interferon. Using IDS partially purified by isoelectric focusing from culture supernatants of concanavalin A-stimulated human peripheral blood mononuclear cells (PBMC), we investigated IDS inhibition of T cell proliferation with respect to the interleukin pathway. At concentrations that produced 75-90% suppression of proliferation in PHA-stimulated PBMC cultures, IDS caused no decrease in interleukin 2 (IL2) production (determined by bioassay) or in IL2 receptor expression (determined with anti-Tac antibody). Moreover, adding exogenous IL2 to IDS-inhibited cultures failed to restore proliferation. IDS inhibited growth of several IL2-dependent and IL2-independent cell lines, and suppressed proliferation of PBMC induced by the phorbol ester TPA (12-0-tetradecanoyl-13-phorbol acetate) or by the calcium ionophore A23187, thus distinguishing its mechanism of action from that of cyclosporin A, dexamethasone, OKT11A antibody, and other inhibitors. These data extend earlier findings that IDS acts late in G1 phase of the cell cycle, and provide evidence that IDS inhibits T cell proliferation through an IL2-independent mechanism.

Responses of pre-implantation mouse embryos to thalidomide exposure in utero.

PIP: On Day 1 of pregnancy, a thalidomide suspension (.05 ml) in saline at concentrations of 5 and 10 mcg/ml was infused into the uterine horns via the cervical route of 2 1/2-3 month old Swiss albino mice. Another group was infused on Day 0 at the doses mentioned. Parallel experiments were conducted after intrauterine infusions of saline. Following infusion, the mice were sacrificed on Days 2, 3, and 4 of gestation. Zygote and 4- and 8-cell stages of embryogenesis were most sensitive to the teratogen in terms of the induction of morphological anomalies and cell death. Drug effect was also observed in the postmorula embryos as abnormalities of varying degrees. There was an overall increase in the incidence of mitotic cells.^ieng

Population control and the women of India.

PIP: 14% of the world's population, (547,000,000 people) live on 2.4% of its land in India. 18% of the population of India live in 2690 cities, the rest in rural villages, with roughly an average of 700 people per village. The woman's role in India was mainly to produce children, most importantly sons. In 1956 India began the program of planned parenthood at a governmental level, aiming at restricting births. This met with some negativism on the part of the older generation especially due to its depriving them of the privilege and benefits of large families, and the lesser guarantee of a male heir. But due to the effects of agricultural and industrial reforms, rapid urbanization has occurred bringing better communication and helping to spread the ideas and information about family planning to the village. Urbanization also brought about a crashing economic situation. Motivation for planned parenthood has its most persuasive impetus when social and economic pressures are at their peak. Thus the message that a "small family is a happy family" has from necessity become accepted. The poor housing conditions with a total lack of privacy has contributed to the inability of Indian women to use more sophisticated methods of contraception. The pill is too expensive for most Indian women. The IUD therefore was the most practical to start with in 1956 and thereafter has been freely available. India's national leadership is committed to the success of the planned parenthood program which aims at the adoption of the norm of a small family as a social and personal ideal. The 2 facets of the program have been to persuade people to accept the new norms and to provide contraceptive services within easy reach. If the birth rate declines from its present level of 39 to 30 per 1000 by 1986, the population will still reach 792,000,000 by 1991, and 941,000,000 by 2001. The reason for the past increase in growth has been due to the rapidly declining death rate. Legislation has been passed to increase the age of marriage, but that is insufficient. It must be followed by attempts at increasing social consciousness on the merits of small families. Family planning has not failed in India, but there is an urgent need to revamp thinking and vitalize activities.^ieng