Effect of temperature on the growth of Staphylococcus aureus in ready-to-eat cooked rice with pork floss.

Cooked rice with pork floss (CRPF) wrapped in dried seaweed is one of the most popular ready-to-eat (RTE) foods in many Asian countries, particularly in Taiwan. The products are susceptible to Staphylococcus aureus contamination and temperature abuse during manufacturing, distribution, and storage. The objective of this study was to examine the effect of temperature on its growth in RTE CRPF for use in risk assessment and prevention of staphylococcal food poisoning (SFP). Inoculated CRPF samples were stored at 4, 12, 18, 25, and 35°C, and the change in the populations of S. aureus during storage were analyzed using three primary models to determine specific growth rate (µmax), lag-phase duration (λ), and maximum population density (ymax). The Ratkowsky square-root and Huang square-root (HSR) models were used as the secondary models to describe the effect of temperature on µmax, and a linear and an exponential regression models were used to describe the effect of temperature on λ and ymax, respectively. The model performance was evaluated by the root mean square error (RMSE), bias factor (Bf), and accuracy factor (Af) when appropriate. Results showed that three primary models were suitable for describing the growth curves, with RMSE ≤ 0.3 (log MPN/g). Using µmax obtained from the Huang model, the minimum growth temperature (Tmin) estimated by the HSR model was 7.0°C, well in agreement with the reported Tmin. The combination of primary and secondary models for predicting S. aureus growth was validated by additional growth curves at 30°C, which showed that the RMSE was 0.6 (log MPN/g). Therefore, the developed models were acceptable for predicting the growth of S. aureus in CRPF under likely temperature abuse conditions and can be applied to assess the risk of S. aureus in CRPF and design temperature controls to reduce the risk of SFP.

Association of Physician Certification Policy and Quality of Care: Evidence of percutaneous coronary intervention certification program in Taiwan.

OBJECTIVES: The aim of this study was to compare procedural, short-term and two-year outcomes of percutaneous coronary intervention (PCI) between board-certified and non-board certified interventional cardiologists in Taiwan. BACKGROUND: Most studies of associations between quality and certification have analyzed populations in the Western developed countries. METHODS: This retrospective population-based study analyzed 2057 patients who had received PCI in 11 hospitals in 2007. The outcome measures were procedural, 30-day, and 2-year adverse events. RESULTS: Sixty certified physicians performed 1771 PCI procedures whereas 84 non-certified physicians performed 286 procedures. Patients treated by non-certified physicians had significantly higher rates of in-hospital mortality (6.99% vs. 2.82%, respectively; p ≤ 0.001) and same-stay CABG (1.40% vs. 0.06%, respectively; p ≤ 0.001). The results of multilevel logistic regression and Cox multivariate regression indicated that patients treated by non-certified physicians also had higher probabilities of in-hospital death (OR=2.92, 95% CI: 1.20-7.08) and two-year death (hazard ratio, 1.63; 95% confidence interval, 1.18-2.24). CONCLUSIONS: This is the first study in Asia in investigating the association between board certification policy and surgical outcomes, and the results confirmed that the board certification policy is also effective for Asian population. The policy implications of these findings are discussed.

Viscolin, a new chalcone from Viscum coloratum, inhibits human neutrophil superoxide anion and elastase release via a cAMP-dependent pathway.

The mistletoe Viscum coloratum is used in traditional Chinese medicine to treat inflammatory diseases. In this study, a cellular model in isolated human neutrophils, which are important in the pathogenesis of rheumatoid arthritis, chronic obstructive pulmonary disease, and other inflammatory diseases, was established to elucidate the anti-inflammatory functions of V. coloratum. The partially purified extract of V. coloratum (PPE-SVC) potently inhibited formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced superoxide anion generation and elastase release in a concentration-dependent manner with IC(50) values of 0.58+/-0.03 and 4.93+/-0.54 microg/ml, respectively. Furthermore, a new chalcone derivative, viscolin (4',4''-dihydroxy-2',3',6',3''-tetramethoxy-1,3-diphenylpropane), was isolated from PPE-SVC. Viscolin was demonstrated to inhibit superoxide anion generation and elastase release, as well as to accelerate resequestration of cytosolic calcium in FMLP-activated human neutrophils. Furthermore, the inhibitory effects of viscolin were reversed by protein kinase A (PKA) inhibitor, suggesting that PKA mediates the viscolin-caused inhibitions. Viscolin induced a substantial increase in cAMP levels, and that occurred through the inhibition of phosphodiesterase (PDE) activity but not an increase in adenylate cyclase function. Consistent with this, viscolin potentiated the PGE(1)-caused inhibition of superoxide anion release and calcium mobilization, as well as elevation of cAMP formation. These results demonstrate that inhibition of inflammatory responses in human neutrophils by viscolin is associated with an elevation of cellular cAMP through inhibition of PDE. Comparable results were also observed by PPE-SVC, indicating that the effect of PPE-SVC is at least partly mediated by viscolin. In summary, viscolin is a novel inhibitor of PDE and might be useful for treatment of neutrophilic inflammation.

Soluble guanylyl cyclase activator YC-1 inhibits human neutrophil functions through a cGMP-independent but cAMP-dependent pathway.

3-(5'-Hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), a novel type of soluble guanylyl cyclase (sGC) activator, is useful in investigating the signaling of cGMP and may provide a new approach for treating cardiovascular diseases. Herein, YC-1 was demonstrated to inhibit the generation of superoxide anion (O2-) and the release of beta-glucuronidase release, to diminish the membrane-associated p47phox and to accelerate resequestration of cytosolic calcium in formyl-l-methionyl-l-leucyl-l-phenylalanine-activated human neutrophils. YC-1 not only directly promoted sGC activity and cGMP formation but also dramatically potentiated sodium nitroprusside-induced sGC activity and cGMP formation in human neutrophils. However, the synergistic increase in the amount of cGMP was inconsistent with its cellular response. Moreover, neither an sGC inhibitor nor protein kinase G inhibitors reversed the inhibitory effect of YC-1. Interestingly, YC-1 also increased the cAMP concentration and protein kinase (PK)A activity. The inhibitory effect of YC-1 was significantly enhanced by prostaglandin (PG)E1 and isoproterenol, and almost abolished by PKA inhibitors. These results show that cAMP, but not cGMP, mediates the YC-1-induced inhibition of human neutrophils. YC-1 increased the PGE1- and forskolin-induced but not 3-isobutyl-1-methylxanthine-produced cAMP formation, suggesting inhibition of phosphodiesterase. These findings thus reveal novel mechanism-mediated anti-inflammatory properties of YC-1 in human neutrophils, which can influence the progression of cardiovascular disease. cAMP, but not cGMP, plays an important role in the regulation of respiratory burst and degranulation in human neutrophils.