Father involvement and children's functioning at age 6 years: a multisite study.

Research suggests that fathers' involvement in their children's lives is associated with enhanced child functioning. The current study examined (a) whether presence of a father was associated with better child functioning, (b) whether children's perceptions of fathers' support was associated with better functioning, and (c) whether the above association was moderated by the father's relationship to the child, the child's race, and the child's gender. Participants included 855 six-year-old children and their caregivers. Father presence was associated with better cognitive development and greater perceived competence by the children. For children with a father figure, those who described greater father support had a stronger sense of social competence and fewer depressive symptoms. The associations did not differ by child's gender, race, or relationship to the father figure. These findings support the value of fathers' presence and support to their children's functioning. Priorities for future research include clarifying what motivates fathers to be positively involved in their children's lives and finding strategies to achieve this.

Comparative in vitro effects of arachidonic acid metabolites on tracheal spirals and parenchymal strips.

We compared the pharmacologic effects of a number of oxidative products of arachidonic acid metabolism, including prostaglandin (PG) F2 alpha, PGD2, PGI2, PGE2 6-keto-PGF1 alpha, and the 9 alpha, 11 alpha and 11 alpha, 9 alpha cyclic ether endoperoxide analogues, with that of histamine on guinea pig tracheal spirals and lung parenchymal strips. These agents demonstrated different profiles of activity on the tracheal (central) and parenchymal (peripheral) airway tissues. None of the metabolites studied exceeded the ability of histamine to constrict the tracheal spirals, whereas the cyclic ether endoperoxide analogues and PGD2 were as good as, or better, constrictors of the parenchymal strips than histamine. This suggests that these mediators, which are formed during hypersensitivity reactions, may play an important role in the peripheral airway constriction that is a part of this syndrome.

Alteration of histamine response by H2-receptor antagonism in the guinea pig.

Effects of H2-receptor antagonism on the response to histamine was studied in the guinea pig in vivo and in vitro. The H2-receptor antagonist, metiamide (100 micro M), resulted in an enhanced histamine response in eight of eight parenchymal strips and in four of eight tracheal spirals. On the average the parenchymal strips were 20-fold more sensitive to histamine (P less than 0.001), whereas the tracheal spirals demonstrated an insignificant, 20%, increase in sensitivity after metiamide treatment. These results are consistent with the hypothesis that there are inhibitory H2-receptors in guinea pig airways and they predominate in the periphery. When we determined the effects of H2-antagonism on the histamine response in vivo we found that the histamine response was enhanced only in animals that had been treated with the beta-receptor antagonist propranolol. In these animals there was a mean 2.2-fold increase in histamine sensitivity. These results suggest that although there are inhibitory H2-receptors in the guinea pig lung, their role in modulating the in vivo response is much less than beta-adrenergic mechanisms.

Bronchodilator activity of dimaprit in the guinea pig in vitro and in vivo.

The bronchodilator activity of the H2-recptor agonist, dimaprit, was assessed in vitro and in vivo. In vitro dimaprit relaxed guinea pig tracheal spirals and parenchymal strips that were constricted by the H1 receptor agonist, 2-PEA, or by carbachol. The H2-receptor antagonist, metiamide, inhibited this effect of dimaprit in vitro on both tissues constricted by 2-PEA but not on the carbachol constricted tracheal spiral. Intravenous infusion of dimaprit in the intact guinea pig resulted in reversal of bronchoconstriction induced by subcutaneous injection of 2-PEA. In vivo pretreatment with the H2-recptor antagonist, metiamide, resulted in a diminished sensitivity to the bronchodilating effects of intravenous dimaprit.

Comparative responses of tracheal spirals and parenchymal strips to histamine and carbachol in vitro.

The responses of isolated guinea pig tracheal spirals and parenchymal strips to histamine and carbachol were compared. The parenchymal strip, a 1.5 x 1.5 x 20-mm strip cut from the periphery of the lung, constricted at a lower dose and had a larger maximal response to histamine than to carbachol. In contrast, the response of the tracheal spiral to equimolar doses of histamine or carbachol was the same. The responsiveness of both muscle strips to histamine was decreased by treatment with the H1 receptor antagonist mepyramine (0.1 micrometer), and the response to carbachol was blocked by treatment with atropine (0.1 micrometer). Indomethacin (3 micrometer), cimetidine (1 micrometer), propranolol (10 micrometer), and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) (4 micrometer) did not alter the differential response of the two strips to histamine and carbachol. The differential response of parenchymal strips with many, few, or no conducting airways and blood vessels was identical, suggesting that the contractile element is alveolar duct smooth muscle or alveolar contractile elements. This differential pharmacologic response in vitro is consistent with the in vivo observation that histamine causes more peripheral airway constriction than does acetylcholine.