The Role of Zinc in Copper Homeostasis of Aspergillus fumigatus.

Copper is an essential metal ion that performs many physiological functions in living organisms. Deletion of Afmac1, which is a copper-responsive transcriptional activator in A. fumigatus, results in a growth defect on aspergillus minimal medium (AMM). Interestingly, we found that zinc starvation suppressed the growth defect of the Δafmac1 strain on AMM. In addition, the growth defect of the Δafmac1 strain was recovered by copper supplementation or introduction of the CtrC gene into the Δafmac1 strain. However, chelation of copper by addition of BCS to AMM failed to recover the growth defect of the Δafmac1 strain. Through Northern blot analysis, we found that zinc starvation upregulated CtrC and CtrA2, which encode membrane copper transporters. Interestingly, we found that the conserved ZafA binding motif 5'-CAA(G)GGT-3' was present in the upstream region of CtrC and CtrA2 and that mutation of the binding motif led to failure of ZafA binding to the upstream region of CtrC and upregulation of CtrC expression under zinc starvation. Furthermore, the binding activity of ZafA to the upstream region of CtrC was inversely proportional to the zinc concentration, and copper inhibited the binding of ZafA to the upstream region of CtrC under a low zinc concentration. Taken together, these results suggest that ZafA upregulates copper metabolism by binding to the ZafA binding motif in the CtrC promoter region under low zinc concentration, thus regulating copper homeostasis. Furthermore, we found that copper and zinc interact in cells to maintain metal homeostasis.

Predictors of patient satisfaction with tertiary hospitals in Korea.

This study examined the general and system-related predictors of outpatient satisfaction with tertiary health care institutions in Korea. A cross-sectional descriptive study design was employed. The subjects were 1,194 outpatients recruited from 29 outpatient clinics of a university medical center in Korea. Measurements included 5 outpatient service domains (i.e., doctor service, nurse service, technician service, convenience, and physical environment of facility) and patient satisfaction. Of the five domains, nurse service was the domain with the highest mean score (M = 4.21) and convenience was the domain with the lowest mean score (M = 3.77). The most significant predictor of patient satisfaction was the constructs of convenience (ß = 0.21). The results of this study suggest that the concept of patient satisfaction with health care institutions in modern hospitals reflects an integrative process that includes not only the concerned health care personnel but also improved convenience such as user-friendly reservation system and comfortable waiting areas.