Illness representations according to age and effects on health behaviors following coronary artery bypass graft surgery.

OBJECTIVES: To determine if illness representations differ as a function of age and how these representations, in conjunction with age, predict postoperative health behaviors. DESIGN: Prospective study of patients undergoing coronary artery bypass graft (CABG) surgery. SETTING: A large metropolitan hospital providing regional cardiac care for patients in a tri-state area, located in Pittsburgh, Pennsylvania. PARTICIPANTS: All consenting patients (N = 309) from a consecutive series of patients scheduled for CABG surgery between January 1992 and January 1994. To be eligible for participation, patients could not be scheduled for any other coincidental surgery (e.g., valve replacement), and could not be in cardiac intensive care or experiencing angina at the time of the referral. Participants were predominantly male (70%) and married (80%), and averaged 62.8 years of age. MEASUREMENTS: Postoperative self-reported health behaviors. RESULTS: Older participants awaiting CABG surgery were significantly more likely to believe old age to be the cause of their coronary heart disease (CHD) and significantly less likely to believe genetics, health-damaging behaviors, health-protective behaviors, and emotions to be the cause of their CHD than were younger participants awaiting surgery. Furthermore, the older participants were significantly more likely to believe they had no control over the disease and that the disease would be gone after surgery, and reported fewer postoperative health behavior changes than did younger participants. CONCLUSION: These findings demonstrate significant differences in illness representations as a function of age. Furthermore, differences in postoperative health behaviors were consistent with differing illness representations.

Optimism and rehospitalization after coronary artery bypass graft surgery.

OBJECTIVE: To determine whether optimism predicts lower rates of rehospitalization after coronary artery bypass graft surgery for the 6 months after surgery. METHODS: A prospective, inception cohort design was used. The sample consisted of all consenting patients (N=309) from a consecutive series of patients scheduled for elective coronary artery bypass graft surgery at a large, metropolitan hospital in Pittsburgh, Pa. To be eligible, patients could not be scheduled for any other coincidental surgery (eg, valve replacement) and could not be in the cardiac intensive care unit or experiencing angina at the time of the referral. Participants were predominantly men (69.9%) and married (80.3%), and averaged 62.8 years of age. Recruitment occurred between January 1992 and January 1994. RESULTS: Compared with pessimistic persons, optimistic persons were significantly less likely to be rehospitalized for a broad range of aggregated problems (including postsurgical sternal wound infection, angina, myocardial infarction, and the need for another bypass surgery or percutaneous transluminal coronary angioplasty) generally indicative of a poor response to the initial surgery (odds ratio=0.50, 95% confidence interval=0.33- 0.76; P=.001). The effect of optimism was independent of traditional sociodemographic and medical control variables, as well as independent of the effects of self-esteem, depression, and neuroticism. All-cause rehospitalization also tended to be less frequent for optimistic than for pessimistic persons (odds ratio=0.77, 95% confidence interval=0.57-1.05; P=.07). CONCLUSIONS: Optimism predicts a lower rate of rehospitalization after coronary artery bypass graft surgery. Fostering positive expectations may promote better recovery.

Chinese hamster ovary cells produce sufficient recombinant insulin-like growth factor I to support growth in serum-free medium. Serum-free growth of IGF-I-producing CHO cells.

Insulin-like growth factor I has similar mitogenic effects to insulin, a growth factor required by most cells in culture, and it can replace insulin in serum-free formulations for some cells. Chinese Hamster Ovary cells grow well in serum-free medium with insulin and transferrin as the only exogenous growth factors. An alternative approach to addition of exogenous growth factors to serum-free medium is transfection of host cells with growth factor-encoding genes, permitting autocrine growth. Taking this approach, we constructed an IGF-I heterologous gene driven by the cytomegalovirus promoter, introduced it into Chinese Hamster Ovary cells and examined the growth characteristics of Insulin-like growth factor I-expressing clonal cells in the absence of the exogenous factor. The transfected cells secreted up to 500 ng/10(6) cells/day of mature Insulin-like growth factor I into the conditioned medium and as a result they grew autonomously in serum-free medium containing transferrin as the only added growth factor. This growth-stimulating effect, observed under both small and large scale culture conditions, was maximal since no further improvement was observed in the presence of exogenous insulin.

Super-CHO-A cell line capable of autocrine growth under fully defined protein-free conditions.

Chinese Hamster Ovary (CHO) cells are widely used for the large scale production of recombinant biopharmaceuticals. Growth of the CHO-K1 cell line has been demonstrated in serum-free medium containing insulin, transferrin and selenium. In an attempt to get autocrine growth in protein-free medium, DNA coding for insulin and transferrin production was transfected into CHO-K1 cells. Transferrin was expressed well, with clones secreting approximately 1000 ng/10(6) cells/24h. Insulin was poorly expressed, with rates peaking at 5 ng/10(6) cells/24h. Characterisation of the secreted insulin indicated that the CHO cells were incompletely processing the insulin molecule. Site-directed mutagenesis was used to introduce a furin (prohormone converting enzyme) recognition sequence into the insulin molecule, allowing the production of active insulin. However, the levels were still too low to support autocrine growth. Further investigations revealed insulin degrading activity (presumably due to the presence of insulin degrading enzymes) in the cytoplasm of CHO cells. To overcome these problems insulin-like growth factor I (instead of insulin) was transfected into the cells. IGF-1 was completely processed and expressed at rates greater than 500 ng/10(6)cells/24h. In this paper we report autonomous growth of the transfected CHO-K1 cell line expressing transferrin and IGF-1 in protein-free medium without the addition of exogenous growth factors. Growth rates and final cell densities of these cells were identical to that of the parent cell line CHO-K1 growing in insulin, transferrin, and selenium supplemented serum-free media.

Person variables and health: personality predispositions and acute psychological states as shared determinants for disease.

This article reviews prospective evidence linking certain classes of person variables to multiple disease end points. Included in the review is a consideration of the effects of hostility and anger, emotional suppression, depression, fatalism, and pessimism on coronary heart disease, cancer, and acquired immunodeficiency syndrome. A model is presented that integrates several of these variables into an overall conceptual scheme. In addition, several variables are identified that appear to moderate the strength of the relationships that are found between person variables and health. The article concludes with some suggested directions for future research.

Distinguishing optimism from neuroticism (and trait anxiety, self-mastery, and self-esteem): a reevaluation of the Life Orientation Test.

Research on dispositional optimism as assessed by the Life Orientation Test (Scheier & Carver, 1985) has been challenged on the grounds that effects attributed to optimism are indistinguishable from those of unmeasured third variables, most notably, neuroticism. Data from 4,309 subjects show that associations between optimism and both depression and aspects of coping remain significant even when the effects of neuroticism, as well as the effects of trait anxiety, self-mastery, and self-esteem, are statistically controlled. Thus, the Life Orientation Test does appear to possess adequate predictive and discriminant validity. Examination of the scale on somewhat different grounds, however, does suggest that future applications can benefit from its revision. Thus, we also describe a minor modification to the Life Orientation Test, along with data bearing on the revised scale's psychometric properties.