Psychosocial predictors of health status revisited.

A one-year prospective design was used to explore health care costs, claims, and job burnout in relation to the following predictors: work and life stress, social support, exercise, Type A behavior, and personal hardiness. Nowack's (1991) model guided the study. A sample of 260 working adults from two organizations participated. Bivariate correlational results suggested that stressful work events were positively related to health care costs and the number of claims filed. With regard to job burnout, (a) stress appeared positively related to personal accomplishment and (b) Type A behavior was associated with greater emotional exhaustion. Higher job satisfaction, social support, and Type A behavior were associated with an increased sense of personal accomplishment. Findings concerning objective health indicators are discussed in relation to previous results pertaining to self-reports of health/illness.

Low power millimeter wave irradiation exerts no harmful effect on human keratinocytes in vitro.

Low power millimeter wave (LP-MW) irradiation has been successfully used in clinical practice as an independent and/or supplemental therapy in patients with various diseases. It is still not clear, however, whether exposed skin is directly affected by repeated LP-MW irradiation and whether cells of the epidermis can be activated by the absorbed energy. Keratinocytes, the most numerous component of the epidermis are believed to manifest functional responses to physical stimuli. In this study we analyzed whether LP-MW irradiation modulated the production of chemokines, including RANTES and IP-10 of keratinocytes in vitro. We also investigated whether LP-MW irradiation induces a heat stress reaction in keratinocytes, and stimulates heat shock protein 70 (Hsp70) production. Vital staining of keratinocytes with carboxyfluorescein succinimidyl ester and ethidium bromide was used to analyze the MW effect on the viability of adherent cells. In addition, we studied the effect of LP-MW irradiation on intercellular gap junctional communication in keratinocyte monolayers by Lucifer yellow dye transfer. We found no significant changes in constitutive RANTES and inducible IP-10 production following LP-MW irradiation. LP-MW exposure of keratinocyte monolayers did not alter Hsp70 production, unlike exposure to higher power MWs (HP-MW) or hyperthermia (43 degrees C; 1 h). LP-MW irradiation and hyperthermia did not alter the viability of adherent keratinocytes, while HP-MW irradiation induced cellular damage within the beam area. Finally, we found no alteration in the gap junctional intercellular communication of keratinocytes following LP-MW irradiation, which on the other hand, was significantly increased by hyperthermia. In summary, we detected no harmful effect of LP-MW irradiation on both keratinocyte function and structure in vitro, although these cells were sensitive to higher MW power that developed heat stress reaction and cellular damage. Our results provide further evidence that LP-MW irradiation does not induce evidence of skin inflammation or keratinocyte damage and that its clinical application appears to be safe.