Shih-Ming Tsao

INHIBITORY EFFECT OF SEVEN ALLIUM PLANTS UPON THREE ASPERGILLUS SPECIES

Antifungal activity and minimal fungicidal concentration (MFC) of extracts of garlic, bakeri garlic, Chinese leek, Chinese chive, scallion, onion bulb and shallot bulb against Aspergillus niger, A. flavus and A. fumigatus were examined. These Allium plants possessed antifungal activity, with garlic showing the lowest MFC. With the exception of scallion, the inhibitory effect of Allium plants against three Aspergillus species decreased with increasing incubation and heating temperature (P < 0.05). Acetic acid treatments of the extracts increased the inhibitory effect for all plants against three fungi (P < 0.05), and there was no significant difference in this effect among the three pH (2, 4, 6) treatments (P > 0.05) investigated. Acetic acid, at pH = 4, plus heat treatments of the extracts resulted in a greater inhibitory effect for all Allium plants against the three fungi than heat treatment alone (P < 0.05). Treatments of the extracts with NaCl, at concentrations of 0.2 and 0.4 M, did not affect the inhibitory effect of the plant extracts. The combination of acetic acid plus Allium plants was indicated to be an effective way to inhibit fungal growth.

Apoptotic effects of protocatechuic acid in human breast, lung, liver, cervix, and prostate cancer cells: potential mechanisms of action.

Apoptotic effects of protocatechuic acid (PCA) at 1, 2, 4, 8 micromol/L on human breast cancer MCF7 cell, lung cancer A549 cell, HepG2 cell, cervix HeLa cell, and prostate cancer LNCaP cell were examined. Results showed that PCA concentration-dependently decreased cell viability, increased lactate dehydrogenase leakage, enhanced DNA fragmentation, reduced mitochondrial membrane potential, and lowered Na(+)-K(+)-ATPase activity for these cancer cells (P < 0.05). PCA also concentration-dependently elevated caspase-3 activity in five cancer cells (P < 0.05), but this agent at 2-8 micromol/L significantly increased caspase-8 activity (P < 0.05). PCA concentration-dependently decreased intercellular adhesion molecule level in test cancer cells (P < 0.05) but significantly inhibited cell adhesion at 2-8 micromol/L (P < 0.05). PCA also concentration-dependently lowered the levels of interleukin (IL)-6 and IL-8 in five cancer cells (P < 0.05), but this agent at 2-8 micromol/L significantly suppressed vascular endothelial growth factor production (P < 0.05). These findings suggest that PCA is a potent anticancer agent to cause apoptosis or retard invasion and metastasis in these five cancer cells.

Extended-Spectrum β-Lactamases and Plasmid-Mediated AmpC Enzymes among Clinical Isolates of Escherichia coli and Klebsiella pneumoniae from Seven Medical Centers in Taiwan

ABSTRACT Production of extended-spectrum β-lactamases and plasmid-mediated AmpC enzymes was investigated among 291 Escherichia coli and 282 Klebsiella pneumoniae isolates that showed decreased susceptibilities to extended-spectrum cephalosporins from seven Taiwanese medical centers. CTX-M-type and SHV-type enzymes were the most prevalent extended-spectrum β-lactamases. CMY-2-like and DHA-1-like β-lactamases were the most prevalent AmpC-type enzymes.

Clinical outcomes of tigecycline alone or in combination with other antimicrobial agents for the treatment of patients with healthcare-associated multidrug-resistant Acinetobacter baumannii infections

Tigecycline (TG) has been shown to be active in vitro against Acinetobacter baumannii, although data on the clinical efficacy of TG alone or in combination for the treatment of infections due to multidrug-resistant A. baumannii (MDRAB) remain limited. The purpose of this study was to investigate the clinical outcomes of patients with healthcare-associated infections (HAIs) caused by MDRAB who were treated with imipenem/cilastatin and sulbactam, and TG alone or in combination with other antibiotics. A total of 386 patients with HAIs caused by MDRAB were retrospectively analyzed and grouped into TG and non-TG groups, depending on whether they received TG treatment. Of the 266 patients in the TG group, 108 were treated with TG alone and 158 were treated with TG in combination with ceftazidime, ceftriaxone, piperacillin/tazobactam, or a carbapenem. All 120 patients in the non-TG group were treated with imipenem/cilastatin and sulbactam. The primary outcome measure was 30-day mortality after TG treatment and the secondary outcome was clinical outcome. There were no significant differences in survival rates between the two groups. However, the rate of unfavorable outcome was significantly lower (p < 0.05) among patients in the TG group than among patients in the non-TG group. The most significant predictor of unfavorable outcome was sepsis, whereas TG treatment and microbial eradication were the most significant predictors of favorable outcomes. Our study represents the largest study of patients with MDRAB infection treated with TG and expands our understanding of the role of TG therapy alone or in combination with other agents for the treatment of HAI caused by MDRAB.

Oxidant Stress and B Vitamins Status in Patients With Non-Small Cell Lung Cancer

Abstract In this study, we examined oxidative stress and B vitamins status in non-small cell lung cancer (NSCLC) patients at different stages. NSCLC patients were divided into 2 groups, stage III (IIIA + IIIB, n = 27) and stage IV (n = 23). A total of 16 healthy control subjects were included for comparison. Plasma levels of α -tocopherol, β -carotene, vitamin C, Se, Cu, Zn, reduced glutathione (GSH), oxidized glutathione (GSSG), lipid oxidation and the activities of glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase, and xanthine oxidase (XO) were determined for evaluating oxidative status in these subjects. B vitamins (B1, B2, B6, B12, folate) in blood and plasma ghrelin level in these subjects were analyzed. Results showed that plasma level of ghrelin and lipid oxidation in NSCLC patients were significantly greater than control groups (P < 0.05). The activity of GPX, SOD, or catalase was significantly reduced, but XO activity was significantly elevated in NSCLC patients (P < 0.05). Plasma level of GSH was significantly lower, but GSSG level was significantly increased in NSCLC patients (P < 0.05). Vitamins B2 and B6 levels in red blood cells (RBC) from NSCLC patients were significantly lower (P < 0.05), and both were negatively correlated with plasma ghrelin. The correlation coefficients were –0.788 and –0.752, respectively. These data suggest that plasma GSH level may be a proper biomarker for evaluating oxidation status for NSCLC patients. RBC levels of vitamins B2 and B6 were reduced in NSCLC patients; thus, the importance of vitamins B2 and B6 for NSCLC patients could not be ignored.

Trends in the Susceptibility of Clinically Important Resistant Bacteria to Tigecycline: Results from the Tigecycline In Vitro Surveillance in Taiwan Study, 2006 to 2010

ABSTRACT The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA) (n = 1,834), penicillin-resistant Streptococcus pneumoniae (PRSP) (n = 423), vancomycin-resistant enterococci (VRE) (n = 219), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 1,141), ESBL-producing Klebsiella pneumoniae (n = 1,330), Acinetobacter baumannii (n = 1,645), and Stenotrophomonas maltophilia (n = 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC90, 0.03 μg/ml), and only one MRSA isolate (MIC90, 0.5 μg/ml) and three VRE isolates (MIC90, 0.125 μg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producing E. coli (MIC90, 0.5 μg/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC90, 2 μg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate for A. baumannii (MIC90, 4 μg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptible A. baumannii isolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptible A. baumannii isolates. In Taiwan, tigecycline continues to have excellent in vitro activity against several major clinically important drug-resistant bacteria, with the exception of A. baumannii.

Diagnostic value of Her-2/neu, Cyfra 21-1, and carcinoembryonic antigen levels in malignant pleural effusions of lung adenocarcinoma

Aims: Cytology fails to detect neoplastic cells in 40–50% of cases of malignant pleural effusion, a condition that frequently accompanies lung adenocarcinoma. Published reports of diagnostic sensitivity of various tumour markers are inconsistent, and optimal cut‐off points have not been determined. This study aimed to evaluate the ability of three markers to discriminate lung adenocarcinoma‐associated malignant pleural effusion (LAC‐MPE) from benign effusion. Methods: Pleural effusion samples were collected from 41 patients with LAC‐MPE, and from 93 with various benign conditions. The diagnostic sensitivity and specificity for Her‐2/neu, Cyfra 21‐1, and carcinoembryonic antigen (CEA) were evaluated. Cut‐off points for these markers are optimally set at 3.6 µg/L, 60 µg/L, and 6.0 µg/L, respectively. Results: Her‐2/neu, Cyfra 21‐1, and CEA vary in their diagnostic accuracy to differentiate LAC‐MPE from benign pleural effusion: 79.85%, 88.81%, and 94.03%, respectively. CEA combined with Cyfra 21‐1 increases diagnostic sensitivity to 97.6%, with a specificity of 91.4%. Conclusions: With appropriate cut‐off points, CEA currently provides the best diagnostic accuracy. Combining CEA with Cyfra 21‐1 increases diagnostic sensitivity to nearly 100%. The results of the present study may help clinicians decide whether to obtain a cytological/histological specimen by invasive means to investigate a possible diagnosis of malignancy.

Antioxidative and Antiinflammatory Activities of Asiatic Acid, Glycyrrhizic Acid, and Oleanolic Acid in Human Bronchial Epithelial Cells

Protective effects of triterpenic acids, asiatic acid (AA), glycyrrhizic acid (GA), or oleanolic acid (OA), for two human bronchial epithelial cells, 16HBE and BEAS-2B cells, against hydrogen peroxide (H2O2) induced injury were examined. Cells were pretreated by triterpenic acid at 4 or 8 μmol/L and followed by H2O2 treatment. Results showed that H2O2 significantly upregulated both Bax and cleaved caspase-3 expression, and also downregulated Bcl-2 expression in test cells. AA at these doses retained Bcl-2 expression, but GA and OA only at 8 μmol/L reserved Bcl-2 expression. Test triterpenic acids lowered cleaved caspase-3 expression dose-dependently. H2O2 treatment lowered Na(+)-K(+)-ATPase activity and mitochondrial membrane potential in cells. Triterpenic acid pretreatments significantly maintained mitochondrial membrane potential and Na(+)-K(+)-ATPase activity. H2O2 enhanced reactive oxygen species, interleukin-6, tumor necrosis factor-α, and prostaglandin E2 levels in test cells. Three triterpenic acid treatments dose-dependently reversed these changes. H2O2 promoted the protein expression of p47(phox), gp91(phox), cyclooxygenase-2 (COX-2), mitogen-activated protein kinase, and nuclear factor-κB (NF-κB). AA, GA, or OA pretreatments dose-dependently downregulated the expression of p47(phox), COX-2, NF-κB p65, and p-p38 but only at 8 μmol/L decreased gp91(phox) expression. These results support that these triterpenic acids could protect bronchial epithelial cells to attenuate apoptotic, oxidative, and inflammatory stress.

Protocatechuic Acid Inhibits Lung Cancer Cells by Modulating FAK, MAPK, and NF-κB Pathways

Cytotoxic effects of protocatechuic acid (PCA) upon 3 nonsmall cell lung cancer (NSCLC) cell lines, A549, H3255, and Calu-6 cell lines, were examined. PCA at 1, 2, 4, and 8 μM was used to treat these cells. Results showed that PCA dose-dependently reduced cell growth; and at 2–8 μM enhanced protein expression of Bax and cleaved caspase-3; as well as diminished Bcl-2 expression. This compound destabilized mitochondrial membrane via increasing caspase-3 activity, decreasing mitochondrial membrane potential and Na+-K+-ATPase activity in these cells. PCA treatments dose-dependently decreased protein expression of vascular endothelial growth factor and fibronectin, as well as lowered interleukin (IL)-6 and IL-8 release; and at 2–8 μM suppressed protein expression of basic fibroblast growth factor, matrix metalloproteinase (MMP)-2 and MMP-9. Furthermore, PCA treatments dose-dependently downregulated nuclear factor kappa (NF-κ)B p50 and NF-κB p65 protein expression, and at 2–8 μM suppressed protein expression of p-p38, p-JNK, and p-focal adhesion kinase (FAK). Our data revealed that PCA declined FAK, mitogen-activated protein kinase, and NF-κB activation, which subsequently decreased the production of cytokines and growth factors, and consequently inhibited proliferation of 3 test NSCLC cells. These findings suggest that PCA could provide wide-ranging anti-NSCLC potency.

In-vitro activity of tigecycline against clinical isolates of Acinetobacter baumannii in Taiwan

We performed susceptibility testing using the microdilution method to determine the in-vitro activity of tigecycline against 393 Acinetobacter baumannii clinical isolates collected in 2006 from 19 hospitals in Taiwan. Significant proportions of the isolates were resistant to imipenem (44%), ciprofloxacin (75%), amikacin (69%), sulbactam (34%) and all four antibiotics (22%), and susceptibility to tigecycline among these different resistant phenotypes of A. baumannii varied from 71% to 82%. The minimum inhibitory concentration (MIC) of tigecycline ranged from 0.6 to 16 microg/mL (MIC(50) 2 microg/mL; MIC(90) 4 microg/mL). The cumulative curve of tigecycline MICs showed that when the MIC cut-offs were set at 2 microg/mL and 4 microg/mL, 80.9% and 93.1% of the isolates were susceptible, respectively. As tigecycline will be used in the future for infections caused by multidrug-resistant A. baumannii because of limited antibiotic choice, and as resistance to tigecycline in A. baumannii isolates may develop following antibiotic exposure, continuous monitoring of the susceptibility of A. baumannii isolates to tigecycline is warranted.