Assessing the relevance of the hopelessness theory of depression to women with disordered eating.

OBJECTIVE: The aim of this study was to investigate the relevance of the hopelessness theory of depression to women with partial-syndrome eating disorders. METHOD: Three groups of women, one meeting criteria for eating disorders not otherwise specified (EDNOS), one with major depression, and a control group, completed the Balanced Attributional Style Questionnaire, the Eating Disorders Examination Questionnaire, and the Beck Depression Inventory. RESULTS: Once levels of depression were controlled, all three groups differed significantly with respect to their attributional style for bad events, with the depressed group showing the greatest tendency to attribute the causes of negative life events to internal factors. However, with respect to the attributional style for good events, the depressed and control group displayed similar styles of attribution, whereas the EDNOS group showed a significantly more dysfunctional style, being more likely to attribute positive events to external factors. DISCUSSION: These findings are discussed in terms of their implications for specific therapeutic interventions with disordered eating.

Genotypic variation for condensed tannin production in trembling aspen (POPULUS TREMULOIDES, salicaceae) under elevated CO2 and in high- and low-fertility soil.

The carbon/nutrient balance hypothesis suggests that leaf carbon to nitrogen ratios influence the synthesis of secondary compounds such as condensed tannins. We studied the effects of rising atmospheric carbon dioxide on carbon to nitrogen ratios and tannin production. Six genotypes of Populus tremuloides were grown under elevated and ambient CO(2) partial pressure and high- and low-fertility soil in field open-top chambers in northern lower Michigan, USA. During the second year of exposure, leaves were harvested three times (June, August, and September) and analyzed for condensed tannin concentration. The carbon/nutrient balance hypothesis was supported overall, with significantly greater leaf tannin concentration at high CO(2) and low soil fertility compared to ambient CO(2) and high soil fertility. However, some genotypes increased tannin concentration at elevated compared to ambient CO(2), while others showed no CO(2) response. Performance of lepidopteran leaf miner (Phyllonorycter tremuloidiella) larvae feeding on these plants varied across genotypes, CO(2), and fertility treatments. These results suggest that with rising atmospheric CO(2), plant secondary compound production may vary within species. This could have consequences for plant-herbivore and plant-microbe interactions and for the evolutionary response of this species to global climate change.

The effects of ethylene oxide sterilization on the in vitro cytotoxicity of a bone replacement material.

The effect of degassing on the cytotoxicity of an ethylene oxide (EtO)-sterilized copolymer constituent of a bone replacement material, was determined using the (51)Cr release assay. An initial experiment used mouse L929 cells and a copolymer with an ambient pressure and temperature (APT) degassing time of 24 hr. Both copolymer and nylon control discs caused a significantly (P

A scanning electron microscopic study of in vitro toxicity of ethylene-oxide-sterilized bone repair materials.

Polylactic acid (PLA) and polyglycolic acid (PGA) have been under investigation for use in the management of hard- and soft-tissue wounds. Current research has included the incorporation of osteo-inductive substances into a PLA-PGA copolymer alloplastic implant material for enhancement of the healing of osseous defects. Conventional methods of sterilization--such as dry heat, steam heat, or 60Co--tend either to destroy or attenuate osteo-inductive activity and alter polymer biodegradation. Ethylene oxide (EO) gas sterilization is currently being tested as an alternate method. This study examined the relationship of EO-induced cytotoxicity to the length of time of polymer aeration following EO sterilization. Three groups of copolymer implant discs were studied: (1) 50:50 PLA-PGA copolymer, (2) PLA-PGA polymer with hydroxyapatite (HA), and (3) PLA-PGA with autolyzed, antigen-extracted (AA) bone particles. Polymer discs, as well as particulate HA and AA bone controls, were sterilized with EO for 12 hours. Following periods of two weeks, one week, one day, or no subsequent vacuum aeration, samples were placed into 24-well culture plates. A suspension of human fibroblasts was added to each well. Cell growth and attachment were permitted for 24 hours. Medium was then removed, and solutions for cell fixation, buffer washing, and dehydration were added to each well. SEM examination revealed changes in cell growth with increasing periods of aeration suggestive of increasing cell vitality. Cells growing on discs having no aeration were small, round, and lobulated, whereas those of seven to 14 days' aeration were more numerous, and flattened with many microvilli, pseudopodia, and dendritic processes, features consistent with normal cell morphology. These results suggest that EO-sterilized polymer implants should be aerated for least seven to 14 days prior to surgical use.