Single-dose tolerance to the behavioral effects of dibutyryl cyclic AMP in mice

The behavioral effects of varying doses of intraperitoneally administered dibutyryl cyclic AMP, cyclic AMP, adenosine, 5-AMP, and butyric acid were studied in male ICR mice. Behavioral parameters 25 min following treatment included measurement of spontaneous locomotor activity (SLMA) and rotarod performance, the latter providing an indication of neuromuscular coordination. Dibutyryl cyclic AMP produced a dose-related inhibition of SLMA with the largest dose, 75 mg/kg, decreasing activity by 89%. Adenosine and 5-AMP produced maximal inhibition of approximately 50–80% of SLMA at doses ranging from 75–250 mg/kg, while cyclic AMP decreased SLMA by 58% at only the highest dose, 250 mg/kg. Butyric acid failed to produce alterations in SLMA at doses ranging from 25–250 mg/kg. No compound altered neuromuscular coordination. Single-dose tolerance to the inhibitory effect of dibutyryl cyclic AMP on SLMA developed within 3 h and lasted at least 7 days. Adenosine failed to produce tolerance while cyclic AMP and 5-AMP exhibited only a slightly reduced effect following a second injection at intervals of 4 and 24 h. These results suggest that exogenous administration of dibutyryl cyclic AMP and its metabolites exert centrally mediated behavioral effects with selective development of single-dose tolerance to the dibutyryl derivative.     

Psychopathology in adolescence.

A cumulative psychiatric case register was utilized to examine patterns of psychopathology in 1,334 adolescent patients. Consistent with studies of adult patients, seriousness of disorder was weighted toward being seen in an inpatient rather than outpatient settling; schizophrenia and personality disorder were relatively more common amoung lower-class patients and neurosis and situational disorder among middle- and upper-class patients; neurosis was more commonly diagnosed among female patients, and personality disorder more commonly diagnosed among males. A ten-year follow-up revealed 54.1% reasonable diagnostic stability on subsequent contacts and 62.2% complete subsequent agreement among patients originally diagnosed as schizophrenic. Aspects of the data demonstrate continuity in adolescent and adult psychopathology, the mythical nature of "normative adolescent turmoil," and what appears to be excesive use of situational disorder in diagnosing adolescent patients.     

Screening for complement deficiency in bacterial meningitis

Seventy-seven children with bacterial meningitis were screened for complement deficiency. Both the classical and the alternate pathways were normal in 75 patients. Transiently reduced total haemolytic activity of the classical pathway was documented in a boy with meningococcal meningitis. Total haemolytic activity of both the classical and the alternate pathways were reduced in another patient with pneumococcal meningitis: individual complement components determination indicated predominant activation of the alternate pathway.     

Effects of cognitive-communication stimulation for Alzheimer's disease patients treated with donepezil.

This randomized study evaluated the combined effect of a cognitive-communication program plus an acetylcholinesterase inhibitor (donepezil; donepezil-plus-stimulation group; n = 26), as compared with donepezil alone (donepezil-only group; n = 28) in 54 patients with mild to moderate Alzheimer's disease (AD; Mini-Mental Status Examination score of 12- 28) ranging in age from 54 to 91 years. It was hypothesized that cognitive-communication stimulation in combination with donepezil would positively affect the following: (a) relevance of discourse, (b) performance of functional abilities, (c) emotional symptoms, (d) quality of life, and (e) overall global function, as measured by caregiver and participant report and standardized measures. Cognitive-communication, neuropsychiatric, functional performance, and quality of life evaluations were conducted at baseline and Month 4, the month after the 2-month active stimulation period. Follow-up evaluations were performed at Months 8 and 12. The stimulation program consisted of 12 hr of intervention over an 8-week period and involved participant-led discussions requiring homework, interactive sessions about AD, and discussions using salient life stories. Additive effects of active stimulation with donepezil were examined in 2 ways: (1) comparing mean group performance over time and (2) evaluating change scores from baseline. A Group x Time interaction was found for the donepezil-plus-stimulation group in the emotional symptoms of apathy and irritability as compared with the donepezil-only group. Evaluation of change scores from baseline to 12 months revealed a positive effect for the donepezil-plus-stimulation group on discourse and functional abilities with a trend on apathy, irritability, and patient-reported quality of life. In sum, the research revealed benefits to the donepezil-plus-stimulation group in the areas of discourse abilities, functional abilities, emotional symptoms, and overall global performance. This study adds to growing evidence that active cognitive stimulation may slow the rate of verbal and functional decline and decrease negative emotional symptoms in AD when combined with acetylcholinesterase inhibitors, indicating a need to advance research in the area of cognitive treatments. The fact that AD is a progressive brain disease should not preclude ameliorative treatment.     

Economic rents derived from hospital privileges in the market for podiatric services

This study examines the relative impacts of human capital and market conditions on the economic rents associated with hospital privileges in the market for footcare. An empirical model of hospital privileges for podiatrists is formulated based on the Pauly-Redisch model of hospital behavior. The privilege model is then incorporated into a model of podiatrists' earnings via a selection adjustment as proposed by Heckman and Lee. The results indicate the persistance of economic rents even after controlling for unobserved 'quality' factors.