Effects of iron and ascorbic acid on acid phosphatases of the enamel organ of rat molars.

Protein extracts from 6- to 11-day-old rat enamel organs were applied to columns of carboxymethyl-52 cellulose. Protein eluted from the columns was assayed for acid phosphatase activity with substrates para-nitrophenylphosphate (p-NPP), beta-glycerolphosphate (beta-GP), ATP and phosphocasein. A weakly-bound peak of activity (A) emerged first which was insensitive to stimulation by iron and ascorbic acid. This enzyme hydrolysed only the phosphomonoester substrates (p-NPP and beta-GP). A strongly bound peak of activity (B) emerged later and was completely separated from the first activity. It hydrolysed all substrates except beta-GP, and was stimulated at least 10-fold by 0.1 mM ferrous ion (Fe2+) in the presence of a strong reducing agent (1.0 mM ascorbic acid). Both substances were more effective as stimulators when used together than they were when each was used separately. Dependency on these co-factors for the development of full activity increased with purification, especially when phosphocasein was substrate. The results were similar for each age of rat used. These properties of enzyme B are parallel with those of the acid phosphoprotein phosphatases of liver and spleen, and the tartrate-resistant acid phosphatase of rat bone. We conclude that enzyme B requires iron and a reducing agent for full activity and has properties that distinguishes it from the classical acid phosphatases (E.C. 3.1.3.2.).

Experience of abuse in primary care patients. Racial and rural differences.

OBJECTIVE: To examine the experience of abuse in rural, urban, black, and white women on the following dimensions: prevalence, symptom experience, health status, medical services utilization, and coping mechanisms. DESIGN: Retrospective study using patient interviews. SETTING: Half the subjects were recruited from a large medical university family medicine center and half from a rural family medicine center, both in the Southeast. PATIENTS: Four hundred seven women were interviewed. Groups were distributed as follows: urban white, 24.9% (n = 99); urban black, 25.6% (n = 102); rural white, 11.1% (n = 44); and rural black, 38.4% (n = 153). MAIN OUTCOME MEASURES: Self-report of abuse (sexual, physical, and emotional) was related to symptom history, current health status, medical services utilization, and coping styles. RESULTS: Sixty-six percent of the total sample reported some kind of abuse. Black, rural women reported the least (52.3%). Presence of greater numbers of symptoms, greater medical services utilization, and lower health status were found in the abused population. Abused women used all types of coping mechanisms to a greater extent than non-abused women. Black women were more likely to use confrontation (F = 8.82 [P = .003]), problem solving (F = 8.24 [P = .004]), and reappraisal (F = 4.13 [P = .04]) than white women. Rural women were more likely to use psychological distancing (F = 5.25 [P = .02]) and escape (F = 5.67 [P = .02]) than urban women, although abused women in general use those coping methods more than nonabused women. CONCLUSIONS: The experience of abuse remains similar across black, white, rural, and urban women; however, coping mechanisms appear to be influenced by group membership.