Spontaneous X chromosome MI and MII nondisjunction events in Drosophila melanogaster oocytes have different recombinational histories.

Recent studies of human oocytes have demonstrated an enrichment for distal exchanges among meiosis I (MI) nondisjunction events and for proximal exchanges among meiosis II (MII) events. Our characterization of 103 cases of spontaneous X chromosome nondisjunction in Drosophila oocytes strongly parallels these observations. The recombinational histories of MI (97/103) and MII (6/103) nondisjunctional ova were strikingly different. MI nondisjunction occurred primarily in oocytes with non-exchange X chromosomes; of the new nondisjoining exchange bivalents, most carried distal crossovers. Thus, spontaneous MI nondisjunction reflects the failure of the achiasmate segregation systems. MII nondisjunction occurred only in oocytes with proximal exchanges. We propose several models to explain how very proximal exchanges might impair proper segregation.

Caregiving for Hispanic Alzheimer's disease patients: understanding the problem.

The authors analyze aspects of caregiving for Hispanic Alzheimer's disease (AD) patients. A review of the literature on caregiving and ethnicity and data concerning caregiving for AD patients in different Hispanic groups are presented. The presence of ethnicity-related differences in caregiving for Hispanic AD patients is confirmed. These differences, however, appear to be present largely in certain areas, such as household composition, distribution of caregiving roles, help-seeking behavior, and site of caregiving. The authors consider areas that need to be addressed in future research and specific modifications to current caregiving models for the study of AD patients in the Hispanic community.

Self-regulation predictors of medication adherence among ethnically different pediatric patients with renal transplants.

OBJECTIVE: To predict medication adherence among ethnically different pediatric patients with renal transplants between the ages of 6 and 20 years old, using self-regulation variables including motivation, perceived control and responsibility, and perceived support. METHODS: Twenty-six African American children and 42 Caucasian children were verbally administered the Self-Regulation of Medication Adherence Battery to assess their (1) motivation to be medication adherent, (2) perceived control of and responsibility for medication adherence, and (3) perceived support of medication adherence from their primary caregiver. Four measures were used to assess medication adherence: self-ratings, nephrologists' ratings, cyclosporine levels, and pill count/refill histories. RESULTS: For the African American patients, regression analyses revealed that responses to motivation and perceived control questions that focused on self-efficacy were unique predictors of medication adherence as rated by their primary nephrologist. For the Caucasian patients, one motivation question regarding how often they forget to take their medication predicted their self-reported adherence. CONCLUSIONS: Facilitating their beliefs that they can regularly take their medications may help promote medication adherence among African American children with renal transplants, whereas for Caucasian children, providing cues and reminders to take their medications may help. We discuss implications of the results for multimodal assessment of medication adherence and for ethnic group-specific medication adherence research and interventions.