The calmodulin-sensitive adenylate cyclase of Bordetella pertussis: cloning and expression in Escherichia coli.

The adenylate cyclase toxin of the prokaryote Bordetella pertussis is stimulated by the eukaryotic regulatory protein, calmodulin. A general strategy, using the adenylate-cyclase-calmodulin interaction as a tool, has permitted cloning and expression of the toxin in Escherichia coli in the absence of any B. pertussis trans-activating factor. We show that the protein is synthesized in a large precursor form composed of 1706 amino acids. The calmodulin-stimulated catalytic activity resides in the amino-terminal 450 amino acids of the adenylate cyclase. The enzyme expressed in E. coli is recognized in Western blots by antibodies directed against purified B. pertussis adenylate cyclase, and its activity is inhibited by these antibodies.

The calmodulin-sensitive adenylate cyclase of Bordetella pertussis: cloning and expression in Escherichia col.

The adenylate cyclase toxin of the prokaryote Bordetella pertussis is stimulated by the eukaryotic regulatory protein, calmodulin. A general strategy, using the adenylate-cyclase-calmodulin interaction as a tool, has permitted cloning and expression of the toxin in Escherichia coli in the absence of any B. pertussis trans-activating factor. We show that the protein is synthesized in a large precursor form composed of 1706 amino acids. The calmodulin-stimulated catalytic activity resides in the amino-terminal 450 amino acids of the adenylate cyclase. The enzyme expressed in E. coli is recognized in Western blots by antibodies directed against purified B. pertussis adenylate cyclase, and its activity is inhibited by these antibodies.

[Abuse in adolescence. Incest. Apropos of 21 cases]. / Sévices à l'adolescence. L'inceste. A propos de 21 observations.

While violent behavior and delinquency in youth have been extensively described, the different patterns of violence that adolescents are subjected to in their families are far less known. Physical abuse is probably as frequent as in childhood and offers some distinctive features because of its appearance or prolongation in adolescence. Moreover, sexual assaults become more important, especially in girls. From review of the literature and the experience of 21 cases of incest observed in the Adolescent Medicine Unit of Hospital Bicêtre, we discuss the circumstances, impact on adolescents and role of the professionals involved. The majority of these cases of incest occur in an impoverished atmosphere, both on psychological and social levels. Intervention strategy is often very delicate.

[Acquired immunodeficiency syndrome in an adolescent hemophiliac]. / Syndrome immunodéficitaire acquis chez un adolescent hémophile.

In an adolescent with hemophilia B, the diagnosis of AIDS was established in face of cachexia, orodigestive candidiasis, associated with lymphopenia, major decrease in T4/T8 ratio with marked decrease in T helper cells and presence of LAV-antibodies. The patient died rapidly from a cerebral infection due to Toxoplasma gondii. Difficulties in diagnosis and treatment of cerebral toxoplasmosis are discussed.

[Resistance and compliance to contraception in adolescents]. / Resistance et compliance a la contraception a l'adolescence.

PIP: Although inadequate information on sex and contraception is frequently believed to account for contraceptive failure in adolescents, other factors including resistence to contraception or poor compliance with method requirements have been invoked to explain contraceptive failures in well-informed adolescents. Sexual relations are beginning at ever-younger ages in France; a 1980 survey indicated that 50% had their 1st sexual relations before age 17. Sexual activity is sporadic and irregular but usually occurs with the same partner. At least 50% of 1st sexual relations are unprotected by contraception, and half of adolescent pregnancies occur in the 1st 6th months of sexual activity. 6-12 months pass on average before sexually active adolescents begin to use contraception. Rates of pregnancy and abortion have increased especially among adolescents under 16, and in 1979 almost 20% of all abortions were in women under 20 years old. In 1980, only 20% of adolescents used contraception, with 17.3% using oral contraceptives. Few statistics exist on the complex phenomenon of conscious or subconscious contraceptive resistence in adolescence, and clinical experience serves as a better guide. A frequent attitude among adolescents is that sexual relations should be spontaneous and romantic, traits viewed as incompatible with contraception. "Magical thinking", failure to appreciate the real risk of pregnancy, and dissociation of sex and pregnancy are common. Adolescents who doubt their fecundity may engage in unprotected relations to reassure themselves, while some seeking to assert their femininity may use pills although they have no need for contraception. Guilt and ambivalence may be unconscious motivations for poor contraceptive use. Young girls in cold, uncaring, neglectful, or conflict-ridden homes may seek affection from a sexual partner and wish to have a baby to demonstrate their attachment. Such situations often lead to well-accepted pregnancies and may also demonstrate a desire for self-affirmation, a search for identity, and a reliving of the mother's own childhood. Very young girls especially may be reluctant to discuss contraception for fear of displeasing their partners or losing their love. Fear of gynecological examinations, distrust of both the side effects of pills and the efficacy of all other contraceptive methods, and rebellion against the adult world are additional reasons for nonuse of contraception. Fears on the part of the mother or resentment of the daughter's maturity and sexuality or other feelings may impede communication and hence acquisition and use of contraception. Resistence by adults in general to expressions of sexuality among adolescents may prevent physicians from prescribing pills and educators from providing information on sex and contraception. Compliance with contraception appears to be a multidimensional phenomenon with 3 principal domaines: individual characteristics, the environment, and the availability of contraception. Unfavorable social situations and young age at initiation of sexual activity are unfavorable to compliance, while a well-defined identity, autonomy, and sense of responsability are favorable. The most important environmental factor is a supportive family, while the type of method appears to be less significant. Careful and sympathetic reception of the adolescent and good follow-up by the health worker can boost compliance.^ieng