Ultrastructural analysis of the interaction between F-actin and respiratory syncytial virus during virus assembly

During respiratory syncytial virus (RSV) infection there is a close physical interaction between the filamentous actin (F-actin) and the virus, involving both inclusion bodies and the virus filaments. This interaction appears to occur relatively early in the replication cycle, and can be detected from 8 h post-infection. Furthermore, during virus assembly we obtained evidence for the participation of an F-actin-associated signalling pathway involving phosphatidyl-3-kinase (PI3K). Treatment with the PI3K inhibitor LY294002 prevented the formation of virus filaments, although no effect was observed either on virus protein expression, or on trafficking of the virus glycoproteins to the cell surface. Inhibition of the activity of Rac GTPase, a down-stream effector of PI3K, by treatment with the Rac-specific inhibitor NSC23766 gave similar results. These data suggest that an intimate interaction occurs between actin and RSV, and that actin-associated signalling pathway, involving PI3K and Rac GTPase, may play an important role during virus assembly.     

Gastrodia elata BL mediates the suppression of nNOS and microglia activation to protect against neuronal damage in kainic acid-treated rats

Our previous studies showed that Gastrodia elata (GE), an herb used in traditional Chinese medicine, has both anti-convulsive and free radical-scavenging activities in kainic acid (KA)-treated rats. The aim of the present study was to further investigate possible physiological mechanisms of GE against activities of neuronal nitric oxide synthase (nNOS) and microglia in KA-treated rats; 0.5 g/kg and 1.0 g/kg of GE extract were administered orally, whereas 20 mg/kg of N-nitro-L-arginine methyl ester (L-NAME) was administered intraperitoneally (ip), both at 30 minutes prior to KA (2 microg/2 microl) being injected into the right hippocampus region of rats. ED1-staining, apoptotic, inducible nitric oxide synthase (iNOS), and nNOS-staining cells were observed in the hippocampus region. The results indicated that 1.0 g/kg of GE and 20 mg/kg of L-NAME reduced the counts of ED1-stained cells, and 0.5 g/kg and 1.0 g/kg of GE, and 20 mg/kg of L-NAME reduced the numbers of apoptotic cells and nNOS-staining cells. In addition, 20 mg/kg of L-NAME also reduced the numbers of iNOS-staining cells, but 0.5 g/kg and 1.0 g/kg of GE did not. This study demonstrated that GE was able to reduce nNOS, microglia activation and apoptosis, suggesting that GE has a protective effect against neuronal damage in KA-treated rats.     

Statins Can Delay Insulin Use and Reduce Diabetes-related Diseases in Asian Patients With Type 2 Diabetes

We evaluated the role of statins in delaying insulin use and diabetes-related diseases in Asian patients with type 2 diabetes mellitus (T2DM) because statins can cause new-onset diabetes.We used data from the Longitudinal Health Insurance Database in this retrospective cohort study. The 12,470 T2DM patients were categorized into 2 cohorts: a statin cohort comprising 2545 patients who received statin therapy for at least 6 months (180 days) before the index date and a nonstatin cohort comprising 9925 patients who did not receive statin therapy. The control-to-case ratio was set at approximately 4:1. Univariable and multivariable Cox proportional hazards regression analyses were performed to evaluate the risk of diabetes-related events and insulin use on receiving statin treatment.Patients in the statin cohort had a 48% lower risk of diabetes-related coma than those in the nonstatin cohort (95% confidence interval = 0.29–0.92). Patients with >730 days of statin therapy had a significantly lower risk of insulin use, diabetes-related disorders of the eye and neurons, and peripheral circulatory disorders. Compared with patients in the nonstatin cohort, the risk of insulin use, diabetes-related coma, and diabetes-related disorders of the eye and neurons was lower in patients on a cumulative defined daily dose (cDDD) of statins for >475 days.These results suggest that longer duration of statin use and higher cDDD of statins can delay insulin use in Asian patients with T2DM.     

Comparative analysis of urinary N7-(2-hydroxyethyl)guanine for ethylene oxide- and non-exposed workers

Ethylene oxide (EO), a direct alkylating agent and a carcinogen, can attack the nucleophilic sites of DNA bases to form a variety of DNA adducts. The most abundant adduct, N7-(2-hydroxyethyl)guanine (N7-HEG), can be depurinated spontaneously or enzymatically from DNA backbone to form abasic sites. Molecular dosimetry of the excised N7-HEG in urine can serve as an EO exposure and potential risk-associated biomarker. This study was to analyze N7-HEG in urine collected from 89 EO-exposed and 48 nonexposed hospital workers and 20 exposed and 10 nonexposed factory workers by using our newly developed on-line solid-phase extraction isotope-dilution LC-MS/MS method. Statistical analysis of data shows that the exposed factory workers excreted significantly greater concentrations of N7-HEG than both the nonexposed factory workers and hospital workers. Multiple linear regression analysis reveals that the EO-exposed factory workers had a significantly greater post-shift urinary N7-HEG than their nonexposed coworkers and hospital workers. These results demonstrate that analysis of urinary N7-HEG can serve as a biomarker of EO exposure for future molecular epidemiology studies to better understand the role of the EO-induced DNA adduct formation in EO carcinogenicity and certainly for routine surveillance of occupational EO exposure for the study of potential health impacts on workers.     

Chrysophanol-induced necrotic-like cell death through an impaired mitochondrial ATP synthesis in Hep3B human liver cancer cells

Liver cancer is the most common form of cancer in Taiwan and it usually responds to chemotherapy. However, patients often have side effects to the chemotherapeutic drugs. Thus new agents are urgently required to treat liver cancer. Chrysophanol, one of the anthraquinone derivatives, was reported to inhibit some human cancer cell growth which may be due to the induction of apoptosis similar to other anthraquinone derivatives though such actions have not been reported. In the present study, we reported that chrysophanol inhibits cell growth in Hep3B liver cancer cells based on the following observations: 1) induc cell morphological changes; 2) decreased percentage of viable cells; 3) induced S phase arrest of cell cycle progression; 4) induced DNA damage as measured by comet assay and DAPI staining. Chrysophanol-induced cell death however, seems to be related to necrotic processes rather than typical apoptosis. Chrysophanol induced reactive oxygen species and Ca(2+) production and decreased mitochondrial membrane potential (ΔΨm) and ATP levels in Hep3B cells. No effects were observed on known protein regulators of apoptosis such as Bax and Bcl-2. Chrysophanol-induced cell death took place independently of caspase-8 and -9. Based on our findings, we propose that chrysophanol reduces cellular ATP levels causing a drop in energy resulting in necrotic-like cell death.     

The modifying effect of CYP2E1, GST,and mEH genotypes on the formation of hemoglobin adducts of acrylamide and glycidamide in workers exposed to acrylamide

This study assesses the association of acrylamide (AA) and glycidamide (GA) hemoglobin adducts (AAVal and GAVal) and their ratios with genetic polymorphisms of the metabolic enzymes cytochrome P450 2E1 (CYP2E1), exon 3 and 4 of microsomal epoxide hydrolase (mEH3 and mEH4), glutathione transferase theta (GSTT1), and mu (GSTM1) or/and the combinations of these polymorphisms, involved in the activation and detoxification of AA in humans. Fifty-one AA-exposed workers and 34 controls were recruited and provided a post-shift blood sample. AAVal and GAVal were determined simultaneously using isotope-dilution liquid chromatography-electronspray ionization/tandem mass spectrometry (LC-ESI–MS/MS). Genetic polymorphisms of CYP2E1, mEH3 and 4, GSTT1, and GSTM1 were also analyzed. Our results reveal that the GAVal/AAVal ratio, potentially reflecting the proportion of AA metabolized to GA, ranged from 0.13 to 0.45 with a mean at 0.27. Multivariate regression analysis demonstrates that the joint effect of CYP2E1, GSTM1, and mEH4 genotypes was significantly associated with AAVal and GAVal levels after adjustment for AA exposures. These results suggest that mEH4 and the combined genotypes of CYP2E1, GSTM1 and mEH4 may be associated with the formation of AAVal and GAVal. Further studies may be needed to shed light on the roles that phase I and II enzymes play in AA metabolism.     

Combination Therapy of Metformin and Statin May Decrease Hepatocellular Carcinoma Among Diabetic Patients in Asia

Previous studies have shown that metformin or statins may decrease hepatocellular carcinoma (HCC) in diabetic patients. Accordingly, this article evaluates whether combination therapy may further reduce HCC.Newly diagnosed type 2 diabetes mellitus (DM) patients, excluding those with history of malignancy prior to the date of DM diagnosis, were recruited to a DM cohort. DM patients developed HCC as the cancer cohort and the date for HCC diagnosis as index date. Non-cancer cohort was frequency matched with 4:1 according to age, sex, DM-year, and index date as case group from DM cohort.Patients who were treated with statins showed a 63% decreased risk of HCC (odds ratio [OR] = 0.37; 95% confidence interval [CI] = 0.27–0.49). Patients who consumed simvastatin, atorvastatin, or rosuvastatin significantly decreased risk for HCC (OR = 0.32, 0.31, and 0.22; 95% CI = 0.18–0.58, 0.19–0.52, and 0.08–0.61, respectively). Metformin combinations with simvastatin, atorvastatin, or rosuvastatin may decrease HCC (OR = 0.30, 0.30, and 0.24; 95% CI = 0.15–0.59, 0.16–0.54, and 0.08–0.70, respectively). The comorbidities for HCC were decreased by consuming simvastatin and atorvastatin (OR = 0.31 and 0.29; 95% CI = 0.14–0.67 and 0.15–0.57, respectively). Only combination therapy of metformin and simvastatin may significantly decreased HCC comorbidities (OR = 0.26; 95% CI = 0.11–0.60) in our study.In Asia, not all metformin combinations with statins may reduce the incidence of HCC and not all of this kind of combination therapy may decrease the HCC comorbidities.     

Prevalence of dysglycaemic events among inpatients with diabetes mellitus: a Singaporean perspective

INTRODUCTION

As the effectiveness of intensive glycaemic control is unclear and recommended glycaemic targets are inconsistent, this study aimed to ascertain the prevalence of dysglycaemia among hospitalised patients with diabetes mellitus in an Asian population and evaluate the current standards of inpatient glycaemic control.

METHODS

A retrospective observational study was conducted at a secondary hospital. Point-of-care blood glucose (BG) values, demographic data, medical history, glycaemic therapy and clinical characteristics were recorded. Dysglycaemia prevalence was calculated as proportions of BG-monitored days with at least one reading exceeding the cut points of 8, 10 and 15 mmol/L for hyperglycaemia, and below the cut point of 4 mmol/L for hypoglycaemia.

RESULTS

Among the 288 patients recruited, hyperglycaemia was highly prevalent (90.3%, 81.3% and 47.6% for the respective cut points), while hypoglycaemia was the least prevalent (18.8%). Dysglycaemic patients were more likely than normoglycaemic patients to have poorer glycated haemoglobin (HbA1c) levels (8.4% ± 2.6% vs. 7.3% ± 1.9%; p = 0.002 for BG > 10 mmol/L) and longer lengths of stay (10.1 ± 8.2 days vs. 6.8 ± 4.7 days; p = 0.007 for BG < 4 mmol/L). Hyperglycaemia was more prevalent in patients on more intensive treatment regimens, such as basal-bolus combination therapy and the use of both insulin and oral hypoglycaemic agents (100.0% and 96.0%, respectively; p < 0.001 for BG > 10 mmol/L).

CONCLUSION

Inpatient glycaemic control is suboptimal. Factors (e.g. type of treatment regimen, discipline and baseline HbA1c) associated with greater prevalence of dysglycaemia should be given due consideration in patient management.     

Association between Total Daily Doses with duration of hospitalization among readmitted patients in a multi-ethnic Asian population

Increased length of stay (LOS) in the hospital incurs substantial financial costs on the healthcare system. Multiple factors are associated with LOS. However, few studies have been done to associate the impact of Total Daily Doses (TDD) and LOS. Hence, the aim of this study is to examine the association between patients’ LOS upon readmission and their TDD before readmission. A retrospective cross-sectional study of readmission cases occurring from 1st January to 31st March 2013 was conducted at a regional hospital. Demographics and clinical variables were collected using electronic medical databases. Univariable and multiple linear regressions were used. Confounders such as comorbidities and drug related problems (DRP) were controlled for in this study. There were 432 patients and 649 readmissions examined. The average TDD and LOS were 18.04 ± 8.16 and 7.63 days ± 7.08 respectively. In the univariable analysis, variables that were significantly associated with the LOS included age above 75 year-old, race, comorbidity, number of comorbidities, number of medications, TDD and thrombocytopenia as DRPs. In the multiple linear regression, there was a statistically significant association between TDD (β = 0.0733, p = 0.030) and LOS. Variables that were found significant were age above 75 year-old (β = 1.5477, p = 0.008), Malay (β = −1.5123, p = 0.033), other races (β = −2.6174, p = 0.007), depression (β = 2.1551, p = 0.031) and thrombocytopenia as a type of DRP (β = 7.5548, p = 0.027). When TDD was replaced with number of medications, number of medications (β = 0.1487, p = 0.021), age of 75 year-old (β = 1.5303, p = 0.009), Malay (β = −1.4687, p = 0.038), race of others (β = −2.6499, p = 0.007), depression (β = 2.1951, p = 0.028) and thrombocytopenia as a type of DRP (β = 7.5260, p = 0.028) were significant. In conclusion, a significant relationship between TDD and number of medications before readmission and the LOS upon readmission was established. This finding highlights the importance of optimizing patients’ TDD in the attempt of reducing their LOS.