Dopamine is required for hyperphagia in Lep(ob/ob) mice.

Feeding is a complex process responsive to sensory information related to sight and smell of food, previous feeding experiences, satiety signals elicited by ingestion and hormonal signals related to energy balance. Dopamine released in specific brain regions is associated with pleasurable and rewarding events and may reinforce positive aspects of feeding. Dopamine also influences initiation and coordination of motor activity and is required for sensorimotor functions. Thus, dopamine may facilitate integration of sensory cues related to hunger, initiating the search for food and its consumption. Dopaminergic neurons in the substantia nigra and ventral tegmental area project to the caudate putamen and nucleus accumbens, where they modulate movement and reward. There are projections from the nucleus accumbens to the lateral hypothalamus that regulate feeding. Dopamine-deficient mice (Dbh(Th/+), Th-/-; hereafter DD mice) cannot synthesize dopamine in dopaminergic neurons. They gradually become aphagic and die of starvation. Daily treatment of DD mice with L-3,4-dihydroxyphenylalanine (L-DOPA) transiently restores brain dopamine, locomotion and feeding. Leptin-null (Lep(ob/ob)) mice exhibit obesity, decreased energy expenditure and hyperphagia. As the hypothalamic leptin-melanocortin pathway appears to regulate appetite and metabolism, we generated mice lacking both dopamine and leptin (DD x Lep(ob/ob)) to determine if leptin deficiency overcomes the aphagia of DD mice. DD x Lep(ob/ob) mice became obese when treated daily with L-DOPA, but when L-DOPA treatment was terminated the double mutants were capable of movement, but did not feed. Our data show that dopamine is required for feeding in leptin-null mice.

Feeding behavior in dopamine-deficient mice.

Mice that cannot make dopamine (DA), a condition caused by the selective inactivation of tyrosine hydroxylase in dopaminergic neurons, are born normal but gradually become hypoactive and hypophagic, and die at 3 weeks of age. We characterized the feeding and locomotor responses of these DA-deficient (DA-/-) mice to 3, 4-dihyroxy-L-phenylalanine (L-DOPA) to investigate the relationship between brain DA levels and these complex behaviors. Daily administration of L-DOPA to DA-/- mice stimulated locomotor activity that lasted 6 to 9 hr; during that time the mice consumed most of their daily food and water. The minimal dose of L-DOPA that was sufficient to elicit normal feeding behavior in the DA-/- mice also restored their striatal DA to 9.1% of that in the wild-type (WT) mice at 3 hr; then DA content declined to <1% of WT levels by 24 hr. This dose of L-DOPA induced locomotor activity that exceeded that of treated WT mice by 5- to 7-fold, suggesting that DA-/- mice are supersensitive to DA. Unexpectedly, DA-/- mice manifested a second wave of activity 24 to 48 hr after L-DOPA treatment that was equivalent in magnitude to that of WT mice and independent of DA receptor activation. The DA-/- mice approached, sniffed, and chewed food during this second period of activity, but they ate <10% of that required for sustenance. Therefore, DA-/- mice can execute behaviors necessary to seek and ingest food, but they do not eat enough to survive.

The Executive Skills Profile: a method for assessing development needs among family medicine faculty.

BACKGROUND AND OBJECTIVES: The purpose of this paper is to report on how the Executive Skills Profile, a measure of job demands and employee skills, can be used as a faculty development tool in academic family medicine departments. METHODS: The Executive Skills Profile (ESP) identifies 72 work activities and groups them into 12 scales, each of which is displayed graphically. Faculty identify the work activities that are relevant to their jobs and then identify the personal skills they must have to carry out those work activities. RESULTS: The ESP successfully characterized the job demands and personal skills of one family medicine department. The evaluation showed that overall perceived job demands were greater than the faculty's perceived personal skills, particularly in the areas of interpersonal and behavioral skills. CONCLUSIONS: The ESP can be used to characterize the job demands and personal skills of faculty.

Cutaneous reactions to surgical preparations and dressings.

A prospective study of 100 surgical patients was undertaken to identify causes of contact dermatitis. Patch testing with the North American Contact Dermatitis Standard Series and additional agents used in the surgical preparation and dressing was performed in 11 patients with post-operative dermatitis or a history of tape allergy. 12 patients were diagnosed as having irritant (mechanical) contact dermatitis. One patient had allergic contact dermatitis to benzoin postoperatively; another patient with a history of an adhesive tape reaction had a positive patch test to thiuram mix, rubber accelerators formerly present in adhesive tapes. Our findings indicate that irritant contact dermatitis is a common problem in the surgical patient. Allergic contact dermatitis is less common, occurring in 2 of the 100 patients.

Dermatoses among poultry workers: "chicken poison disease".

To investigate the causes of skin eruptions affecting poultry workers, we reviewed our medical records and surveyed a southcentral Pennsylvania poultry processing plant. Examination of the records of routine patch test clinic patients seen from January, 1981, to July, 1982, revealed three poultry workers with allergic contact dermatitis and one with irritant contact dermatitis. We then examined one hundred fifty workers at a poultry processing plant, noting the presence of occupational dermatoses, with special interest in the occurrence of contact dermatitis. We found thirteen dermatoses in nine workers. These included Candida infections, irritant contact dermatitis, allergic contact dermatitis, abrasions and cuts, warts, and dyshidrotic eczema.