Mental Well‐Being Mediates the Relationship between Perceived Stress and Perceived Health

The association between stress and health has been well researched in the past; however, comparatively few mediators have been tested to understand the underlying mechanism. With increasing awareness on mental well‐being, this study evaluated the relationship between perceived stress and perceived health and examined mental well‐being as a mediator. Two‐hundred undergraduates aged 21 to 26 years completed the English Perceived Stress Scale, Health Status Questionnaire and Asian Mental Well‐Being Scale that assess perceived stress, perceived health and mental well‐being, respectively. Factor analysis and structural equation modelling on the Perceived Stress Scale replicated the reported two‐factor structure after excluding an insignificant item. Linear multiple regression analyses indicated that perceived stress was negatively associated with perceived health. Results showed that mental well‐being partially mediated the relationship between perceived stress and perceived health, although it is acknowledged that this association could be bidirectional. Findings from the present study suggest that future research could focus on reducing stress and improving mental well‐being to alleviate the effect of stress on health. Copyright © 2013 John Wiley & Sons, Ltd.     

Assessment of aldehyde dehydrogenase in viable cells

Cytosolic aldehyde dehydrogenase (ALDH), an enzyme responsible for oxidizing intracellular aldehydes, has an important role in ethanol, vitamin A, and cyclophosphamide metabolism. High expression of this enzyme in primitive stem cells from multiple tissues, including bone marrow and intestine, appears to be an important mechanism by which these cells are resistant to cyclophosphamide. However, although hematopoietic stem cells (HSC) express high levels of cytosolic ALDH, isolating viable HSC by their ALDH expression has not been possible because ALDH is an intracellular protein. We found that a fluorescent aldehyde, dansyl aminoacetaldehyde (DAAA), could be used in flow cytometry experiments to isolate viable mouse and human cells based on their ALDH content. The level of dansyl fluorescence exhibited by cells after incubation with DAAA paralleled cytosolic ALDH levels determined by Western blotting and the sensitivity of the cells to cyclophosphamide. Moreover, DAAA appeared to be a more sensitive means of assessing cytosolic ALDH levels than Western blotting. Bone marrow progenitors treated with DAAA proliferated normally. Furthermore, marrow cells expressing high levels of dansyl fluorescence after incubation with DAAA were enriched for hematopoietic progenitors. The ability to isolate viable cells that express high levels of cytosolic ALDH could be an important component of methodology for identifying and purifying HSC and for studying cyclophosphamide-resistant tumor cell populations.     

Accuracy of supplementary serologic testing for human T-lymphotropic virus types I and II in US blood donors. Retrovirus Epidemiology Donor Study

Blood donations in the United States have been screened for antibody to human T-lymphotropic virus type I (HTLV-I) by HTLV-I enzyme immunoassay (EIA) since November 1988. Specimens repeatedly found to be reactive by EIA undergo confirmation by supplementary serologic tests. We assessed the accuracy of blood center testing of 994 HTLV-I EIA repeat-reactive specimens in five US blood centers between November 1988 and December 1991. Of 410 confirmed HTLV-I/II donations, 407 (99.3%) were infected with HTLV-I/II, as determined by polymerase chain reaction (PCR) (403 cases) and by repeat serologic testing (4 cases). The three false- positive results occurred in the first year of testing. Of 425 HTLV- indeterminate specimens, 6 (1.4%) were found to be infected by PCR (5 with HTLV-II and 1 with HTLV-I). None of 159 confirmatory test-negative donations was PCR positive. Of HTLV-I/II-seropositive specimens, 80.2% to 95.4% could be typed as HTLV-I or HTLV-II by type-specific serologic assays. These results support recommendations that HTLV-I/II- seropositive donors should be advised that they are infected with HTLV- I, HTLV-II, or HTLV-I/II (depending on results of type-specific assays). HTLV-indeterminate donors should be advised that their results only rarely indicate HTLV infection. HTLV confirmatory test-negative donors should be reassured that they are not infected with HTLV-I or HTLV-II.     

Charlson Comorbidity Index Is an Important Prognostic Factor for Long-Term Survival Outcomes in Korean Men with Prostate Cancer after Radical Prostatectomy

Purpose

To analyze overall survival (OS), prostate cancer (PCa)-specific survival (PCaSS), and non-PCaSS according to the Charlson Comorbidity Index (CCI) after radical prostatectomy (RP) for PCa.

Materials and Methods

Data from 336 patients who had RP for PCa between 1992 and 2005 were analyzed. Data included age, preoperative prostate-specific antigen (PSA), prostate volume, clinical stage, and pathologic stage. Pre-existing comorbidities were evaluated by the CCI, and patients were classified into two CCI score categories (0, ≥1).

Results

The mean age of patients was 64.31±6.12 years. The median PSA value (interquartile range, IQR) was 11.30 (7.35 and 21.02) ng/mL with a median follow-up period (IQR) of 96.0 (85.0 and 121.0) months. The mean CCI was 0.28 (0-4). Five-year OS, PCaSS, and non-PCaSS were 91.7%, 96.3%, and 95.2%, respectively. Ten-year OS, PCaSS, and non-PCaSS were 81.9%, 92.1%, and 88.9%, respectively. The CCI had a significant influence on OS (p=0.022) and non-PCaSS (p=0.008), but not on PCaSS (p=0.681), by log-rank test. In multivariate Cox regression analysis, OS was independently associated with the CCI [hazard ratio (HR)=1.907, p=0.025] and Gleason score (HR=2.656, p<0.001). PCaSS was independently associated with pathologic N stage (HR=2.857, p=0.031), pathologic T stage (HR=3.775, p=0.041), and Gleason score (HR=4.308, p=0.001). Non-PCaSS had a significant association only with the CCI (HR=2.540, p=0.009).

Conclusion

The CCI was independently associated with both OS and non-PCaSS after RP, but the CCI had no impact on PCaSS. The comorbidities of a patient should be considered before selecting RP as a curative modality for PCa.     

A comparison between central blood pressure values obtained by the Gaon system and the SphygmoCor system

Central pulse pressure is correlated with carotid atherosclerosis and the incidence of cardiovascular events more significantly than brachial pulse pressure. Augmentation index (Aix) has been shown to be an independent predictor of cardiovascular morbidity and mortality. Pulse wave analysis using the Gaon system allows for the estimation of central blood pressure (CBP), corrected augmentation index (Aix@HR75), ejection duration (ED) and subendocardial viability ratio (SEVR), and is widely used in clinical research in Korea. However, the accuracy of this system is controversial. From February 2008 to March 2011, 99 patients were recruited for this study. Measurements were taken both by the Gaon system and the SphygmoCor system on the same day for all study participants. The estimated values of CBP, Aix@HR75, ED and SEVR for the two systems were compared using paired t-tests, simple correlation analyses and Bland-Altman plots. Systolic blood pressure (SBP) estimated by the two systems was significantly (P<0.001) correlated; the coefficient was 0.982. The two s.d. of the difference in SBP between these systems was quite small--<7?mm?Hg. Aix@HR75, ED and SEVR as estimated by the two systems were also significantly correlated, although they, especially SEVR, showed much weaker correlations than were observed in SBP: coefficients for Aix@HR75, ED and SEVR were 0.727, 0.648 and 0.230, respectively. We assessed the CBP of Korean patients estimated by the two systems and observed that the correlations of Aix, ED and SEVR were weaker than that of CBP. Such variations may be due to the difference in measuring methods between the devices. As even a slight change in pulse waveforms may result in a large difference in estimations, parameters, including Aix@HR75, ED and SEVR, should be carefully interpreted by experienced clinicians.