Clonidine and lidamidine (WHR-1142) stimulate sodium and chloride absorption in the rabbit intestine

The effects of clonidine and lidamidine on ion transport in the intestine of the rabbit were determined. In the ileum both clonidine (10(-6) M) and lidamidine (10(-3) M) (a) decreased the short circuit current (-1.9 +/- 0.3 and -2.0 +/- 0.4 muEq/h . cm2, respectively) and potential difference; (b) increased net sodium absorption (2.0 +/- 0.6 and 1.8 +/- 0.4 muEq/h . cm2) and chloride absorption (3.4 +/- 0.5 and 3.4 +/- 0.6 muEq/h . cm2); and (c) increased tissue conductance (8.7 +/- 1.7 and 10.0 +/- 1.6 mmho/cm2). The increase in net sodium and chloride absorption was primarily due to an increase in mucosal-to-serosal movement of the ions and a decrease in serosal-to-mucosal movement of chloride. The action of clonidine on the short circuit current was quantitatively similar to the action of epinephrine. Both were readily reversed by yohimbine, a specific alpha 2-adrenergic antagonist. Further, methoxamine, an alpha 1-adrenergic agonist has no effect on the short circuit current up to the concentration of 10(-5) M; and prazosin, an alpha 1-adrenergic antagonist, did not affect the change of the short circuit current induced by epinephrine. The results indicate the presence of alpha 2-adrenergic receptors on the intestine and suggest that alpha 2-adrenergic stimulation may account for the effect of epinephrine on ion transport. Lidamidine was studied because it is structurally related to clonidine and has many similar actions. Yohimbine transiently reversed the effect of lidamidine. alpha 1-Adrenergic or dopaminergic antagonists did not reverse the effect of lidamidine, suggesting that it may affect alpha 2-adrenergic receptors. The results indicate that both clonidine and lidamidine stimulate electrolyte absorption and may be clinically useful.

Hearing loss and treatment in young Down's syndrome children

Twenty-four home-reared Down's syndrome children aged 9-32 months were assessed by trained audiologists on three separate occasions (summer, autumn and spring 1977-1978). Distraction test procedures were used; all failed to pass the screening test and 80-85% registered as having moderate to profound losses. Seventy-five per cent were categorized as having a conductive loss and some improvements were found over the test sessions as a result of surgical and decongestant treatment. Approximately 50% of the infants had been passed on similar screening procedures by the local health services. The results are discussed in relation to language development and service needs.

A study of the hearing and receptive vocabulary of the trainees of an adult training centre

Hearing and receptive vocabulary (E.P.V.T. full-range version) of the trainees of an adult training centre have been studied. A high incidence of hearing loss (47.1 per cent) was found. The correlation between receptive vocabulary and hearing loss was significant at the five per cent level for the adult Down syndrome subjects in the study. Recommendations are made on the services required, particularly with reference to audiology, that could significantly contribute to the reduction in the number of hearing-impaired mentally handicapped subjects who are at present in hospital care.