Fate of the monoamine oxidase inhibitor pargyline in cultured hepatocytes

The interaction of the monoamine oxidase inhibitor pargyline with cultured hepatocytes has been studied. [Phenyl-3, benzyl-3H] pargyline (38 nM) rapidly enters the cells and a plateau of incorporation into a trichloroacetic acid insoluble form (monoamine oxidase) is reached after 2 hr. The level of labelling is lower in freshly isolated cells than in those in later culture. The maximum incorporation accounts for only 6% of the added radioactivity and produces a 9% inhibition of monoamine oxidase activity. The remaining [3H] pargyline is metabolized and quickly accumulates in the cell culture medium in a form which cannot label exogenous mitochondria. The metabolism of pargyline varies both qualitatively and quantitatively with culture age. In 0 hr and 20 hr-cultured cells one metabolite preferentially appears whilst in 140 hr cultured hepatocytes at least three metabolites are formed. The metabolism of [3H] pargyline in early culture is consistent with a cytochrome P-450 involvement. The use of [3H] pargyline to label monoamine oxidase in cultured hepatocytes offers several attractive features for studying the turnover of this enzyme. These include speed of interaction, non-reutilization, application to normal cells, controlled inhibition of monoamine oxidase and metabolism of non-specific label.     

An elective in primary care internal medicine for students in the preclinical years

A two-week elective to introduce first- and second-year medical students to primary care internal medicine was developed and evaluated. Course time is divided between conference sessions (25 percent) provided by full-time clinical faculty members and office experience (75 percent) provided by volunteer clinical faculty members (general internists in private practice and in prepaid health plans). Evaluations by the students (n = 58) who took the elective consisted of a questionnaire assessment of the conference session topics, the student's ability to carry out course objectives, and the preceptor's teaching activities. The conference topics were highly rated, with a mean score of 4.1 on a rating scale ranging from 1 (unfavorable) to 5 (favorable). The course objectives and teaching activities were also well rated, with a mean score of 4.1 and 3.9, respectively, on a rating scale ranging from 1 (none) to 5 (outstanding).     

Esophageal pH monitoring for gastroesophageal reflux: a United Kingdom study

Esophageal pH monitoring is the accepted standard for the investigation of gastroesophageal reflux (GER) in adults. A postal questionnaire was sent to 912 United Kingdom paediatric physicians & surgeons. Five hundred forty-seven (61%) replied, with 124 (22.7%) currently using the technique, mostly in conjunction with barium swallow and/or esophagoscopy. The use of pH monitoring to quantify GER was also accepted in principal as being the best determinant of reflux by a further 186 (34%), but as yet was unavailable in their hospitals. Pediatricians were also questioned as to their management of children with GER. The majority were treated medically with a variety of antireflux medication, with only 237 (42%) referring cases for surgery.