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Objective: New medical discoveries regarding genetic susceptibility to common chronic diseases, and the decoding of the human genome have increased public attention to genetics. What information is understood and what attitudes exist towards genetics and genetic research have not been well examined in underserved, culturally diverse communities. Methods: To better understand attitudes and beliefs towards genetics and genetic testing in these groups, we conducted eight focus groups with 55 patients and health care workers in New York City and Westchester, N.Y., in English, Spanish, and Chinese. Results: Focus group participants had limited understanding about genetics or genetic testing. Newborn screening was the least-known genetic issue, even among health care workers. Regardless of their cultural group, most participants expressed a desire for more information about genetics and genetic tests. Latinos and Chinese participants generally expressed positive attitudes towards genetic studies and genetic testing, with the possibility of preventing diseases cited as the main advantage. Black Americans and Non-Hispanic Whites reported mixed feelings about genetic research and genetic testing. Concerns expressed included: anxiety before receiving test results or waiting for a disease to develop, fear of genetic discrimination by health and life insurance companies and employers, not having the financial means to deal with genetic diseases in themselves or a sick child, concern that children and adults are having too many tests. Black Americans expressed the most concern for possibly harmful use of genetic information. Conclusions: Minority populations of diverse cultures have limited knowledge about genetics and genetic testing, would like to have more information, and are not well reached by the current educational approaches. Participants knew the least about newborn screening, a test that is mandatory in the New York State. While genetic knowledge by minority populations was perhaps not different from the level of knowledge of consumers in general, minority populations are at particular risk of being left behind because of historically poor access to information and services.

The phosphorylase isoenzyme composition of soluble preparations isolated from potato (Solanum tuberosum L. cv. Spunta) tuber-derived callus has been studied by polyacrylamide gel electrophoresis and affinity electrophoresis. Native electrophoretic profiles indicate that dedifferentiated callus tissue contains a single form of phosphorylase that differs in primer requirement, charge and affinity towards branched α-1,4/1,6-glucans from the major phosphorylase form (phosphorylase II) in potato tuber. This latter molecular form is missing in dedifferentiated callus. However, callus phosphorylase appears to be closely related to tuber phosphorylase I, a minor form found in the original explant tissue.

Envelope membranes were isolated from potato tuber amyloplast by a discontinuous sucrose density gradient and high speed centrifugation. These membranes catalyzed the transfer of [14C]glucose from UDP-[14C]glucose to endogenous sterol acceptors and, in turn, catalyzed the esterification of steryl glucosides with fatty acids from an endogenous acyl donor. The synthesis of steryl glucosides was stimulated in the presence of Triton X-100, while formation of acyl steryl glucosides was inhibited by the detergent. However, in the presence of an added sterol acceptor and Triton X-100, the inhibition of acyl steryl glucoside synthesis was overcome by the addition of phosphatidylethanolamine. The enzyme involved in steryl glucoside formation was solubilized by treatment of the envelope membranes with 0-3% Triton X-100. The solubilized enzyme had an almost absolute requirement for sterol acceptors.

Steryl glucoside (SG) and acylated steryl glucoside (ASG) synthesis was investigated in amyloplast membranes from young, intermediate and mature potato tubers. The synthesis ratio SG/ASG was lowest in young tubers (3:2) and highest in mature tubers (6:1). About a 3-fold stimulation of [14C] glucose incorporation into a mixture of SG was observed in amyloplast membranes from mature tubers in the presence of β-sitosterol, while radioactivity incorporation in young tubers was unaffected, thus indicating that different availabilities of endogenous acceptors occur in the membranes. The enzymes involved in sterol modification exhibit a different behavior towards Triton X-100, depending on the developmental stage of the tubers. Low concentrations of the detergent (0.045%) are required to stimulate the enzymes present in young tuber membranes (2-fold). On the other,hand, 0.15% of Triton increased the enzymatic activity in mature tubers 5-fold. These results, together with those obtained after studies of pH dependence, could be related to the lipidic structure of the vesicles formed at different developmental stages of the tubers. It is concluded that the major changes in the enzymatic activities occur as a consequence of the sterol acceptors and acyl donor content during potato tuber growth.