GENERAL WELL-BEING AND USE OF SOCIAL SUPPORT

Research interest on well-being and social support has focused largely on social factors as related to attaining and maintaining well-being, self-perceptions of well-being and to a lesser extent the relationship of current level of self-perceived well-being to use of formal or informal sources of social support. This study analyzed responses to the General Well-Being Schedule of 6,913 subjects (25-74 years) interviewed during the National Health and Nutrition Examination Survey (1971-1975). The purpose of this analysis was to relate the level of GWBS scores to the use of social support, both informal (family and friends) and formal (community professionals).^ Study questions addressed were whether well-being level was related to selection of a specific social support resource and/or rate of use of resources and whether gender differences were apparent in level of well-being and social support use. Because age, sex, race, socioeconomic status (income and education) and marital status may confound the relation between level of GWB and type of social support chosen, the association between these variables with GWB and use of social support were considered. For analysis, test scores were grouped into four categories and for detailed analysis, two categories: low (0-70) and high (71-110). Cross tabulations and percentages were computed and the chi-square test of significance was used.^ Although 16 to 25 percent of the sample population reported low well-being, less than 10 percent used formal resources to discuss emotional, mental or behavior problems. Medical resources, mostly physicians, were the most used formal social supports. Informal social support was important for all well-being levels where 65-77% of each category reported using this resource.^ While well-being level does not appear to serve as a screener/selector of type of formal social support used, it is related to rates of use. Females reported slightly lower well-being than males, and except in the lowest well-being group, had higher rates of social support use. Findings support the conclusion that perceived well-being is related to use of social support such that the lower the well-being, the greater tendency to use formal and/or informal social support. ^

The role of Lmx1b in the control of dorsoventral compartmentalization in the distal mesenchyme of the developing mouse limb

Lmx1b encodes a LIM-homeodomain transcription factor required for dorso-ventral (D-V) patterning in the mesenchyme of the vertebrate limb. In the absence of Lmx1b function, limbs exhibit a bi-ventral pattern indicating that Lmx1b is required for cells to adopt a dorsal cell fate. However, how Lmx1b specifies dorsal cell fates in the mesenchyme of the distal limb is unknown. Lmx1b is initially expressed throughout the dorsal and ventral limb bud mesenchyme, then becomes dorsally restricted around E10.5. At this stage, there is a sharp boundary between Lmx1b expressing and Lmx1b non-expressing cells. How the dorso-ventral Lmx1b expression boundary is formed and maintained is currently unknown. One mechanism that may contribute to establishing and/or maintaining the Lmx1b expression boundary is if the dorsal mesenchyme is a lineage-based compartment, where different groups of non-mingling cells are separated. Compartment formation has been proposed to rely on compartment-specific selector gene activity which functions to restrict cells to a compartment and specifies the identity of cells within that compartment. Based on the evidence that the dorsal limb identity relies on the expression of Lmx1b in the dorsal half of the limb mesenchyme, we hypothesized that Lmx1b might function as a dorsal limb bud mesenchyme selector gene to set up a dorsal compartment. To test this hypothesis, we developed an inducible CreERT2/ loxP based fate mapping approach that permanently marks Lmx1b wild-type and mutant cells and examined the distribution of their descendents in the developing limb. Our data is the first to show that dorso-ventral lineage compartments exist in the limb bud mesenchyme. Furthermore, Lmx1b is required for maintenance of the dorso-ventral compartment lineage boundary. The behavior of Lmx1b mutant cells that cross into the ventral mesenchyme, as well as previous chimera analysis in which mutant cells spread evenly in the ventral limb and form patches in the dorsal side, suggest that cell affinity differences prevent intermingling of dorsal and ventral cells. ^