Usefulness of heart rate variability indices in assessing the risk of an unsuccessful return to work after sick leave in depressed patients.

AIM: The present study aimed to examine whether heart rate variability (HRV) indices in depressed patients measured at return to work after sick leave are related to the outcome of reinstatement. METHODS: This study included 30 workers who took a leave of absence due to major depressive disorder. HRV was measured twice, once when participants left work and another when they returned to work. One month after returning to work, 19 participants continued their original work (successful return group), while 11 failed to perform their original work (unsuccessful return group). HRV indices including high- and low-frequency components (HF and LF) were calculated in three conditions within a session lasting for about 5 minutes, initial rest (Rest), mental task (Task), and rest after task (After), and were compared between the two participant groups. Psychological states were evaluated using Self-rating Depression Scale and State-Trait Anxiety Inventory. RESULTS: No significant differences were observed in the HRV indices on leaving work between groups. On returning to work, the "unsuccessful return group" exhibited lower HF Rest score, higher HF Task/Rest ratio, and higher LF/HF Rest score than the "successful return group." Psychological scores improved in both groups. CONCLUSION: These results indicate that autonomic dysregulations revealed by HRV measurement at return to work after a leave of absence in MDD patients were related to the outcome of reinstatement and can serve as useful information for the assessment of the risk of unsuccessful return.

Purification, cDNA cloning, and expression profiles of the cyclobutane pyrimidine dimer photolyase of Xenopus laevis.

Photolyase is a light-dependent enzyme that repairs pyrimidine dimers in DNA. Two types of photolyases have been found in frog Xenopus laevis, one for repairing cyclobutane pyrimidine dimers (CPD photolyase) and the other for pyrimidine-pyrimidone (6-4)photoproduct [(6-4)photolyase]. However, little is known about the former type of the Xenopus photolyases. To characterize this enzyme and its expression profiles, we isolated the entire coding region of a putative CPD photolyase cDNA by extending an EST (expressed sequence tag) sequence obtained from the Xenopus database. Nucleotide sequence analysis of the cDNA revealed a protein of 557 amino acids with close similarity to CPD photolyase of rat kangaroo. The identity of this cDNA was further established by the molecular mass (65 kDa) and the partial amino acid sequences of the major CPD photolyase that we purified from Xenopus ovaries. The gene of this enzyme is expressed in various tissues of Xenopus. Even internal organs like heart express relatively high levels of mRNA. A much smaller amount was found in skin, although UV damage is thought to occur most frequently in this tissue. Such expression profiles suggest that CPD photolyase may have roles in addition to the photorepair function.