γ-Tocotrienol enhances autophagy of gastric cancer cells by the regulation of GSK3ß/ß-Catenin pathway.

γ-Tocotrienol (γ-T3) is a major subtype of vitamin E, mainly extracted from palm trees, barley, walnuts, and other plants. γ-T3 has effects on anti-inflammation, anti-oxidation, and potential chemoprevention against malignancies. It is still uncompleted to understand the effect of γ-T3 on the inhibitory mechanism of cancer. This study aimed to investigate whether γ-T3 enhanced autophagy in gastric cancer and the underlying molecular mechanism. The results showed that γ-T3 (0-90 µmol/L) inhibited the proliferation of gastric cancer MKN45 cells and AGS cells, and arrested the cell cycle at the G0/G1 phase in a dose-dependent manner. Autophagy was increased in MKN45 cells treated with γ-T3 (0-45 µmol/L), especially at a dose of 30 µmol/L for 24 h. These effects were reversed by 3-methyladenine pretreatment. Furthermore, γ-T3 (30 µmol/L) also significantly downregulated the expression of pGSK-3ß (ser9) and ß-catenin protein in MKN45 cells, and γ-T3 (20 mg/kg b.w.) effectively decreased the growth of MKN45 cell xenografts in BABL/c mice. GSK-3ß inhibitor-CHIR-99021 reversed the negative regulation of GSK-3ß/ß-Catenin signaling and autophagy. Our findings indicated that γ-T3 enhances autophagy in gastric cancer cells mediated by GSK-3ß/ß-Catenin signaling, which provides new insights into the role of γ-T3 enhancing autophagy in gastric cancer.

The role of circulating microRNA-126 (miR-126): a novel biomarker for screening prediabetes and newly diagnosed type 2 diabetes mellitus.

Recent studies suggested an association of endothelial microRNA-126 (miR-126) with type 2 diabetes mellitus (T2DM). In the current study, we examined whether circulating miR-126 is associated with T2DM and pre-diabetic syndrome. The study included 82 subjects with impaired glucose tolerance (IGT), 75 subjects with impaired fasting glucose (IFG), 160 patients with newly diagnosed T2DM, and 138 healthy individuals. Quantitative polymerase chain reaction (qPCR) was used to examine serum miR-126. Serum miR-126 was significantly lower in IGT/IFG subjects and T2DM patients than in healthy controls (p<0.05). After six months of treatment (diet control and exercise in IGT/IFG subjects, insulin plus diet control and exercise in T2DM patients), serum miR-126 increased significantly (p<0.05). An analysis based on serum miR-126 in the sample revealed a significantly higher odds ratio (OR) for the subjects with the lowest 1/3 of serum miR-126 for T2DM (OR: 3.500, 95% confidence interval: 1.901-6.445, p<0.05) than subjects within the highest 1/3 of serum miR-126. Such an association was still apparent after adjusting for other major risk factors. The area under the curve (AUC) for the receiver-operating characteristic (ROC) analysis was 0.792 (95% confidence interval: 0.707-0.877, p<0.001). These results encourage the use of serum miR-126 as a biomarker for pre-diabetes and diabetes mellitus, as well as therapeutic response.

Metabolomics analysis reveals an effect of homocysteine on arachidonic acid and linoleic acid metabolism pathway.

An increase in serum homocysteine level has been associated with an increased risk of vascular disease; however, the biochemical mechanisms that underlie these effects remain largely unknown. The present study aimed to use high-performance liquid chromatography-mass spectrometry (HPLC­MS) to demonstrate the effects of serum homocysteine on human blood metabolites. A total of 75 fasting serum samples were investigated in the present study. Using a threshold of 15 µmol/l serum homocysteine level, samples were divided into high­ and low­homocysteine groups, and the serum extracts were analyzed with an HPLC­MS­based method. A total of 269 features exhibited significant differences and correlation with serum homocysteine levels in the electrospray ionization­positive [ESI(+)] mode, and 69 features were identified in the ESI(­) mode between the two groups. The principal component analysis plot revealed a separation between the high­ and the low­homocysteine groups. Metabolite set enrichment analysis identified arachidonic acid metabolism and linoleic acid metabolism as the two pathways with significantly enriched differences. These results revealed that arachidonic acid and linoleic acid metabolism may be associated with serum homocysteine levels and may be involved in homocysteine-induced vascular disease.

Update of the Providence Health System experience with the CarboMedics prosthesis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to update the authors' experience with the CarboMedics bileaflet mechanical prosthesis in terms of early and long-term outcomes. METHODS: Between July 1994 and April 2005, a total of 774 CarboMedics valves was implanted at two Providence Health System hospitals in Portland Service Area. Of these valves, 406 (59%) were aortic valve replacements (AVR), 196 (28.5%) were mitral valve replacements (MVR), and 86 pairs (12.5%) were double valve replacements (DVR). RESULTS: The mean and maximum follow up was 4.6 and 10.2 years, respectively; total follow up was 3,150 patient-years (pt-yr) (total 3,503 valve-years). Operative mortality was 5.7% (4.4% for AVR, 7.7% for MVR, 7.0% for DVR). Five- and 10-year survivals respectively were 79 +/- 2% and 55 +/- 10% for AVR, 74 +/- 3% and 57 +/- 8% for MVR, and 64 +/- 6% and 39 +/- 11% for DVR (p = 0.009). Freedom from valve explant at five and 10 years respectively was 98 +/- 1% and 97 +/- 10% for AVR, 98 +/- 1% and 86 +/- 12% for MVR, and 96 +/- 3% and 96 +/- 3% for DVR (p = 0.950). Freedom from thromboembolism at five and 10 years respectively was 93 +/- 1% and 91 +/- 2% for AVR, 97 +/- 1% and 95 +/- 2% for MVR, and 90 +/- 4% and 90 4% for DVR (p = 0.226). Freedom from bleeding at five and 10 years respectively was 98 +/- 1% and 97 +/- 1% for AVR, 97 +/- 1% and 96 +/- 2% for MVR, and 91 +/- 4% and 91 +/- 4% for DVR (p = 0.006). Freedom from endocarditis at five and 10 years respectively was 99 +/- 1% and 99 +/- 1% for AVR, 98 +/- 1% and 98 +/- 1% for MVR, and 95 +/- 3% and 91 +/- 4% for DVR (p = 0.030). There were nine perivalvular leaks (six after AVR, three after MVR), and three valve thromboses (two after MVR, one after DVR). Freedom from overall valve-related events at five and 10 years respectively was 80 +/- 2% and 74 +/- 3% for AVR, 82 +/- 3% and 57 +/- 11% for MVR, and 69 +/- 6% and 66 +/- 6% for DVR (p = 0.074). CONCLUSION: Long-term experience with the CarboMedics valve shows the clinical performance of the valve to be very good, with results comparable to those obtained with other mechanical valves.

Durability of pericardial versus porcine aortic valves.

OBJECTIVES: This study compares the long-term performance of the Carpentier-Edwards (CE) porcine bioprosthesis and the CE pericardial bioprosthesis for aortic valve replacement (AVR). BACKGROUND: With new bioprostheses on the horizon, there is renewed interest in how the long-term durability of current pericardial bioprostheses compares with the traditional porcine bioprosthesis. METHODS: We reviewed 518 AVR with CE porcine valves from 1974 to 1996 and 1,021 AVR with CE pericardial valves from 1991 to 2002. The age distribution and clinical profiles were similar for both groups. The total (mean) follow-up was 3,322 (6.4) years for porcine and 2,556 (2.5) years for pericardial. RESULTS: Long-term mortality was similar (p = 0.29) for porcine and pericardial, with 10-year survival rates of 34 +/- 2% and 38 +/- 6%, respectively. Ten-year freedom from major adverse cardiac events was also similar for both (respectively): thromboembolism (80 +/- 2% and 87 +/- 2%; p = 0.24); endocarditis (98 +/- 1% and 99 +/- 1%; p = 0.30). However, 10-year freedom from explant was lower for porcine (90 +/- 2%) than for pericardial (97 +/- 1%, p = 0.04). Reasons for explant for porcine were structural valve deterioration (SVD) (n = 25), endocarditis (n = 4), and periprosthetic leak (n = 2). The reasons for explant for pericardial were SVD (n = 4), endocarditis (n = 4) and periprosthetic leak (n = 1). CONCLUSIONS: The current CE pericardial valve offers better midterm durability than the traditional CE porcine valve. Its freedom from SVD and reoperation makes it our current bioprosthesis of choice for AVR in appropriately selected patients.

Downregulation of SUMF2 gene in ovalbumin-induced rat model of allergic inflammation.

Sulfate-modifying factor 2 (SUMF2), a member of the formylglycine-generating enzyme family, was earlier found to play a role in the regulation of interleukin (IL)-13 expression and secretion in airway smooth muscle cells. IL-13 is a T helper 2 cytokine that plays important roles in the pathogenesis of asthma. However, there is little evidence of the potential role of SUMF2 in the cellular inflammatory responses in asthma. Here, using an ovalbumin-induced asthma rat model, we show that SUMF2 gene expression is significantly decreased in allergic asthma rats. Moreover, several pathological changes were observed in the lung tissue and IL-13 was found to be overexpressed in the ovalbumin-induced asthma model. Additional studies on the lung bronchial epithelial tissues, peripheral blood lymphocytes and bronchoalveolar lavage fluid of the OVA-induced asthma rats showed that SUMF2 mRNA and protein expression were attenuated. However, there was only a little significant correlation was found between SUMF2 and IL-13 expression. These results indicate that SUMF2 may mediate airway inflammation in allergic asthma by modulating the expression of IL-13. More data from in vivo experiments are needed to clearly understand the role of SUMF2 in asthma.

Continuous insulin infusion reduces mortality in patients with diabetes undergoing coronary artery bypass grafting.

OBJECTIVE: Diabetes mellitus is a risk factor for death after coronary artery bypass grafting. Its relative risk may be related to the level of perioperative hyperglycemia. We hypothesized that strict glucose control with a continuous insulin infusion in the perioperative period would reduce hospital mortality. METHODS: All patients with diabetes undergoing coronary artery bypass grafting (n = 3554) were treated aggressively with either subcutaneous insulin (1987-1991) or with continuous insulin infusion (1992-2001) for hyperglycemia. Predicted and observed hospital mortalities were compared with both internal and external (Society of Thoracic Surgeons 1996) multivariable risk models. RESULTS: Observed mortality with continuous insulin infusion (2.5%, n = 65/2612) was significantly lower than with subcutaneous insulin (5.3%, n = 50/942, P <.0001). Likewise, glucose control was significantly better with continuous insulin infusion (177 +/- 30 mg/dL vs 213 +/- 41 mg/dL, P <.0001). For internal comparison, multivariable analysis showed that continuous insulin infusion was independently protective against death (odds ratio 0.43, P =.001). Conversely, cardiogenic shock, renal failure, reoperation, nonelective operative status, older age, concomitant peripheral or cerebral vascular disease, decreasing ejection fraction, unstable angina, and history of atrial fibrillation increased the risk of death. For external comparison, observed mortality with continuous insulin infusion was significantly less than that predicted by the model (observed/expected ratio 0.63, P <.001). Multivariable analysis revealed that continuous insulin infusion added an independently protective effect against death (odds ratio 0.50, P =.005) to the constellation of risk factors in the Society of Thoracic Surgeons risk model. CONCLUSION: Continuous insulin infusion eliminates the incremental increase in in-hospital mortality after coronary artery bypass grafting associated with diabetes. The protective effect of continuous insulin infusion may stem from the effective metabolic use of excess glucose to favorably alter pathways of myocardial adenosine triphosphate production. Continuous insulin infusion should become the standard of care for glycometabolic control in patients with diabetes undergoing coronary artery bypass grafting.

Forty-year survival with the Starr-Edwards heart valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to update an analysis of the long-term survival of heart valve replacement using the Starr-Edwards prosthesis. METHODS: Cases of isolated aortic (AVR, n = 2,247) and mitral (MVR, n = 1,406) valve replacement with Starr-Edwards prostheses implanted between 1960 and 1997, with follow up to 2003, were reviewed. Introduced in 1965, the Models A1200/1260, M6120 are still in use (Current), while other models have been discontinued (Discontinued). For AVR, 938 valves were Discontinued, with a total follow up of 8,506 patient-years (pt-yr) and a maximum of 41 years; by comparison, 1,309 valves were Current, with a total follow up of 11,586 pt-yr and a maximum of 36.1 MVR, were Discontinued, with a total follow up of 6,454 pt-yr and maximum of 37.2 years; and 771 valves were Current, with a total follow up of 6,211 pt-yr and maximum of 37.0 years. RESULTS: Kaplan-Meier (KM) survival at 10 years was 53% for AVR and 51% for MVR; KM survival at 20 years was 23% for both AVR and MVR; KM survival at 30 years was 8% for both AVR and MVR; KM survival at 40 years was 4% for AVR. The standard error for all KM percentages was 1%. Four patients are currently alive with their original valves, more than 40 years after implantation. CONCLUSION: This series of patients, who underwent valve replacement with the Starr-Edwards valve, now have a follow up extending beyond 40 years, thereby confirming the excellent durability of this valve.

[Arsenic trioxide induced apoptosis and expression of p53 and bcl-2 genes in human small cell lung cancer cells].

OBJECTIVE: To study the arsenic trioxide (As(2)O(3)) induced apoptosis in a human small cell lung cancer cell line (NeI-H cells) and its possible mechanisms. METHODS: Apoptotic cells were detected by the TUNEL method. The expression of p53 and bcl-2 was analyzed with immunohistochemical staining. RESULTS: NeI-H cells showed the sub-G(1) peak after treatment with As(2)O(3) (0.5 micromol/L, 1.0 micromol/L, and 2.0 micromol/L) for 72 hours. The ratio of apoptotic cells increased with the increasing concentrations of the drug and the time of culture. Immunohistochemical staining of NeI-H cells showed increased expression of p53, but decreased expression of bcl-2 with the increasing concentrations of the drug. CONCLUSION: The anti-carcinogenic effect of As(2)O(3) is due to the induction of cell apoptosis. Up-regulation of the p53 gene and down-regulation of the bcl-2 gene may be an underlining mechanism.

Stability of miR-126 in Urine and Its Potential as a Biomarker for Renal Endothelial Injury with Diabetic Nephropathy.

Background. The purpose of the present study was to assess the feasibility of using miR-126 in the urine as a biomarker for diabetic nephropathy. Methods. miRNAs were extracted from the urine samples of T2DM patients with diabetic nephropathy (DN; n = 92), T2DM without DN (n = 86), and 85 healthy volunteers using quantitative reverse transcriptase polymerase chain reaction (real-time polymerase chain reaction) analysis. Stability of urinary miR-126 and factors that affected the stability were assessed. A subgroup analysis was also carried out to compare the urinary miR-126 level in T2DM patients well controlled by the treatment versus those who were not well controlled. Results. Urinary miR-126 was stable when the urine samples were kept at room temperature for extended period of time, 4°C, -20°C, and -80°C for up to 12 hours or subjected to 10 freeze-and-thaw cycle. Urinary miR-126 was significantly higher in T2DM patients with DN (5.76 ± 0.33 versus 3.25 ± 0.45 in T2DM patients without DN). Successful treatment significantly reduced urinary miR-126 in T2DM patients with DN to 3.89 ± 0.52 (P < 0.05). Conclusion. miR-126 in the urine is stable and it could be used as a biomarker of DN and to monitor the treatment response.

Cost-effectiveness of aortic valve replacement in the elderly: an introductory study.

OBJECTIVE: With increased life expectancy and improved technology, valve replacement is being offered to increasing numbers of elderly patients with satisfactory clinical results. By using standard econometric techniques, we estimated the relative cost-effectiveness of aortic valve replacement by drawing on a large prospective database at our institution. By using aortic valve replacement as an example, this introductory report paves the way to more definitive studies of these issues in the future. METHODS: From 1961 to 2003, 4617 adult patients underwent aortic valve replacement at our service. These patients were provided with a prospective lifetime follow-up. As of 2005, these patients had accumulated 31,671 patient-years of follow-up (maximum 41 years) and had returned 22,396 yearly questionnaires. A statistical model was used to estimate the future life years of patients who are currently alive. In the absence of direct estimates of utility, quality-adjusted life years were estimated from New York Heart Association class. The cost-effectiveness ratio was calculated by the patient's age at surgery. RESULTS: The overall cost-effectiveness ratio was approximately 13,528 dollars per quality-adjusted life year gained. The cost-effectiveness ratio increased according to age at surgery, up to 19,826 dollars per quality-adjusted life year for octogenarians and 27,182 dollars per quality-adjusted life year for nonagenarians. CONCLUSIONS: Given the limited scope of this introductory study, aortic valve replacement is cost-effective for all age groups and is very cost-effective for all but the most elderly according to standard econometric rules of thumb.

Mitral valve repair on the beating perfused heart.

It is difficult to assess the success of mitral valve repair in the arrested heart. Various techniques have been described. Transesophageal echocardiogram (TEE) provides excellent two-dimensional evaluation of the repair, but three-dimensional anatomic characteristics are limited. We describe a simple technique for performing mitral valve repair on the beating heart. This allows accurate evaluation of valvular competence and three-dimensional anatomic characteristics prior to closure of the atriotomy.

Long-term survival of patients after coronary artery bypass graft surgery: comparison of the pre-stent and post-stent eras.

BACKGROUND: Although coronary artery bypass graft surgery (CABG) has long been the "gold standard" for treatment of multivessel coronary artery disease, current percutaneous interventional technologies are challenging that claim. We sought to determine long-term survival after isolated CABG to establish a baseline for comparison with interventional patients. METHODS: From 1968 through 2003, 20,835 patients underwent 22,378 isolated CABG procedures by a single surgical team. The intermittent fibrillation technique without use of cardioplegia was consistently utilized as a method of myocardial protection, using cardiopulmonary bypass. Patients were prospectively followed with direct contact at annual intervals. Age stratified survival was analyzed. Long-term survival was compared between pre-stent era patients and post-stent era patients. RESULTS: Operative mortality was 2.5% (95% confidence interval: 2.2% to 2.7%) and remained approximately constant since 1974 despite increasing patient age and comorbidities. Follow-up was 84% complete with 172,773 patient-years. Overall 5-, 15-, 25-, and 35-year survival was 86% +/- 0.3%, 48% +/- 0.5%, 19% +/- 0.6%, and 7% +/- 1.2%. By Cox regression, older age, prior myocardial infarction, hypertension, diabetes mellitus, and history of CABG were risk factors for long-term survival. Surgery performed during the post-stent era was a protective factor for long-term survival. CONCLUSIONS: This study presents the long-term survival of a large series of patients after CABG performed by a single surgical team with intermittent fibrillation technique. There was no difference in observed survival up to 8 years between the pre-stent and post-stent eras. This study establishes a baseline of long-term CABG survival that could be used for comparison with other methods of surgical, or nonsurgical coronary revascularization.

Effect of arsenic trioxide on human hepatoma cell line BEL-7402 cultured in vitro.

AIM:To study the effect of a varying concentrations of arsenic trioxide on human hepatoma cell line BEL-7402 cultured in vitro and its mechanism of action.METHODS:The BEL-7402 cells were treated with arsenic trioxide (at the concentrations of 0.5 1 2&mgr;mol/L, respectively) for 4 successive days. The cell growth and proliferation were observed by cell counting and cell-growth curve. Morphologic changes were studied with electronmicroscopy. Flow cytometry was used to assay cell-DNA distribution and the protein expression of Bcl-2 and Bax detected by immunocytochemical method.RESULTS:The cell growth was significantly inhibited by varying concentrations of arsenic trioxide as revealed by cell counting and cell-growth curve, which was dose- and time-dependent. Arsenic trioxide treatment at 0.5, 1 and 2&mgr;mol/L resulted in a sub-G1 cell peak, the apoptosis rate of the control group was 9.31% and that of 0.5&mgr;mol/L arsenic trioxide 15.53%, no significant difference was seen between the two.The apoptosis rates of 1,2&mgr;mol/L arsenic trioxide were 19.10% and 21.87% respectively, which were much higher (both P < 0.05). Decrease of G(0)/G(1) phase cells and increase of S phase cells were observed by flow cytometry, suggesting the inhibition effect of 0.5, 1, 2&mgr;mol/L arsenic trioxide on BEL-7402 cell lay in the G(0)/G(1) phase. Morphologic changes such as intact cell membrane, nucleic condensation, apoptotic body formation were seen under transmission electronmicrescopy, whereas the 0.5mol/L arsenic trioxide-treated BEL-7402 cells showed decrease of nucleocytoplasmic ratio, round nucleus, well-differentiated organelles in the cytoplasm. The processes and microvilli on the cell surface of the experimental groups under scanning electron microscopy were significantly decreased. High expressions of Bcl-2 and Bax were detected in 1 and 2&mgr;mol/L arsenic trioxide-treated cells, these were 46%, 87.33% and 83.08%, 95.83% respectively, among which that of Bax was more significant. Arsenic trioxide treatment at 0.5&mgr;mol/L resulted in a higher expression level of Bcl-2 and lower expression level of Bax,which were 8.81% and 3.83% respectively, as compared with that of the control group (15.33%) (P(1)<0.01, P(2)<0.01).CONCLUSION:Arsenic trioxide not only inhibited proliferation but also induced apoptosis of human hepatoma cell line BEL-7402. The induced-apoptosis effect of 1,2&mgr;mol/L arsenic trioxide was related to the expression level of Bcl-2 and Bax.