Determinants of work among older adults in urban China

Objective: We examined the role of personal, family and institutional factors on the work status of older adults in urban China. Method: The analysis was based on data from a large population survey (N = 7381) of community‐dwelling urban Chinese aged 60 years and older. Multivariate logistic regression was used to model work status. Results: Demographic variables such as gender, ethnicity, age and self‐perceived health status were identified as important determinants of work status. Having material assets, savings, a public pension and health insurance were all negatively correlated with remaining in the workforce, whereas earning a high income was positively correlated. Conclusions: Our findings have implications regarding the impact of health policy and pension reform on employment retention. While economic growth may create an incentive for some to continue working, the lack of widespread public and private old‐age support may force others to remain in the workforce out of economic necessity.     

Health behaviors and their determinants in multiethnic, active Israeli seniors

To assess factors that affect the adoption of healthy lifestyles among a variety of active Israeli seniors, a survey was conducted in 2002 at the Peiluyada, a physical activity-oriented health fair for seniors held annually in Israel from 1995 to 2002. A multi-language, self-administered questionnaire, assessing predisposing factors, barriers and health-protective behaviors, was fielded to potential participants. Response rate at the event was 51%. Hebrew and Arabic speakers generally characterized their health as good to very good, while Russian speakers' health was rated only poor to fair. Over 80% engaged in regular physical activity, were satisfied with their diet, and conformed to international nutritional recommendations. Vaccination coverage against influenza (81%) and pneumocccocus (58%) was highest among Arabic speakers, and lowest among Russian speakers (33.5% and 12%, respectively). Higher age (> or =75 years) was significantly associated with receiving a vaccination against influenza. Major barriers to exercise included low motivation and poor physical health or disability. Health-related dietary restrictions were the leading nutritional barrier. Prominent barriers to vaccination included concerns about vaccine effectiveness (39%) and side effects (29%). Leading cues to action were a recommendation from one's doctor (67%) and from a healthcare worker (51%).     

Intrapituitary adenoviral administration of 7B2 can extend life span and reverse endocrinological deficiencies in 7B2 null mice

The prohormone convertase PC2 requires the aid of a helper protein, known as 7B2, for production of active enzyme. Deletion of 7B2 results in a lethal phenotype resembling Cushing's disease. In this study, we have investigated the effect of a single low dose of recombinant adenovirus vector encoding 7B2 and delivered directly to the pituitary of 7B2 nulls on pituitary ACTH, plasma ACTH, corticosterone, alpha MSH and glucose, and survival time. We show that after injection of recombinant adenovirus encoding 27-kDa 7B2 into 7B2 nulls, transgene expression, as measured by RIA for 7B2, exhibits a transient elevation in the pituitary and blood, with a slight but significant elevation of PC2 activity in pituitaries of 7B2 nulls and a drop in the level of circulating ACTH concomitant with a small increase in circulating alpha MSH. The level of circulating blood glucose was increased, and that of corticosterone was decreased. Lastly, slight but significantly prolonged survival times were observed. These data showing partial rescue of 7B2 nulls support the idea that adenoviral administration of 7B2 will represent an effective means to study the role of this interesting neuroendocrine protein on endocrine function in vivo.     

Baroreflex sensitivity and heredity in essential hypertension.

BACKGROUND. Abnormalities in baroreflex control of heart rate may be important in the pathogenesis of essential hypertension. METHODS AND RESULTS. To investigate the influence of heredity on baroreflex function, we measured baroreflex sensitivity in 40 untreated patients with essential hypertension grouped by the presence (FH+) or absence (FH-) of a family history of hypertension and in 24 normotensive counterparts. Baroreflex sensitivity was assessed by both high-pressure (phenylephrine bolus) and low-pressure (amyl nitrite inhalation) stimuli. Subject groups were matched for age, blood pressure, body weight, and race. Baroreflex sensitivity (in milliseconds per millimeter of mercury) assessed by amyl nitrite inhalation was 24.3 +/- 2.8 in FH- normotensives, 12.3 +/- 1.7 in FH+ normotensives, 15.4 +/- 3.3 in FH- hypertensives, and 8.1 +/- 1.2 in FH+ hypertensives. Baroreflex sensitivity assessed by phenylephrine bolus was 28.8 +/- 5.6 in FH- normotensives, 19.3 +/- 2.8 in FH+ normotensives, 19.1 +/- 2.0 in FH- hypertensives, and 13.6 +/- 1.3 in FH+ hypertensives. Two-factor analysis of variance showed significant effects on baroreflex sensitivity for blood pressure status (normotensive versus hypertensive) and for family history of hypertension. After control line (controlling) for the effects of several variables, including age, mean arterial pressure, body weight, and race through multiple linear regression analysis, the effect of family history of hypertension on baroreflex sensitivity was still highly significant. Indeed, of all variables investigated, family history of hypertension was the strongest unique baroreflex sensitivity predictor. CONCLUSIONS. These data suggest that the impairment in baroreflex sensitivity in hypertension is in part genetically determined and may be an important hereditary component in the pathogenesis of essential hypertension.     

UV-C irradiation disrupts platelet surface disulfide bonds and activates the platelet integrin alphaIIbbeta3

UV-C irradiation has been shown to be effective for pathogen reduction in platelet concentrates, but preliminary work indicated that UV-C irradiation of platelets can induce platelet aggregation. In this study, the mechanism underlying this phenomenon was investigated. Irradiation of platelets with UV-C light (1500 J/m(2)) caused platelet aggregation, which was dependent on integrin alphaIIbbeta3 activation (GPIIb/IIIa). This activation occurred despite treatment with several signal transduction inhibitors known to block platelet activation. UV-C also induced activation of recombinant alphaIIbbeta3 in Chinese hamster ovary (CHO) cells, an environment in which physiologic agonists fail to activate. Activation of alphaIIbbeta3 requires talin binding to the beta3 tail, yet alphaIIbbeta3-Delta724 (lacking the talin binding site) was activated by UV-C irradiation, excluding a requirement for talin binding. The UV-C effect appears to be general in that beta(1) and beta(2) integrins are also activated by UV-C. To explain these findings, we investigated the possibility of UV-C-induced photolysis of disulfide bonds, in analogy with the activating effect of reducing agents on integrins. Indeed, UV-C induced a marked increase in free thiol groups in platelet surface proteins including alphaIIbbeta3. Thus, UV-C appears to activate alphaIIbbeta3 not by affecting intracellular signal transduction, but by reduction of disulfide bonds regulating integrin conformation.