Localization of iNKT subsets determines lipid response (APP2P.101)

iNKT cells can be rapidly activated by α-galactosylceramide (α-GalCer), and α-GalCer or analogues of it are being tested for clinical use against certain cancers and autoimmune diseases. Recent studies in our lab showed that iNKT cells are comprised of NKT1, NKT2 and NKT17 effector subsets. In the current study, we asked whether these different iNKT subsets respond equivalently to α-GalCer using Nur77GFP transgenic mice to quantify the antigen specific response. We observed a robust response by NKT1, but not NKT2, in the spleen, despite in vitro stimulation showing they could be equivalently activated. Using an in vivo antibody-labeling technique, we found that NKT1 possess significantly higher accessibility to blood than NKT2, suggesting that NKT1 cells are preferentially localized to red pulp. This was confirmed by tetramer-based immunofluorescence studies. As expected, i.v. labeled iNKT cells showed a greater response than unlabeled cells. Thus, iNKT cells with accessibility to blood are the predominant cells to respond to lipid. Consistent with this, we observed a robust response of liver iNKT cells, and no response by lymph node iNKT cells, regardless of the subset. Because iNKT subsets produce distinct cytokines, their differential response to i.v. lipids is a critical consideration in therapeutic applications.

Detection of indoxyl sulfate levels in dogs and cats suffering from naturally occurring kidney diseases

Indoxyl sulfate (IS), a protein-bound uraemic toxin, has been found to accumulate in the serum of people with renal diseases and is associated with free radical induction, nephrotoxicity cardiovascular toxicity, and osteoblast cytotoxicity. Although IS has been studied in humans and in experimental models, the role of IS in dogs and cats with kidney disease has not been investigated. A high performance liquid chromatography system was applied to detect plasma IS concentrations in non-azotaemic animals (63 dogs, 16 cats) and in animals with renal azotaemia (66 dogs, 69 cats). The IS levels of azotaemic animals were significantly higher (P <0.01) than those of non-azotaemic animals (median [IQR] 20.4 (9.5) mg/L vs. 7.2 (8.8) mg/L for dogs; median [IQR] 21 (18.9) mg/L vs. 14.8 (12.3) mg/L for cats). The IS level was significantly correlated with blood urea nitrogen, serum creatinine and phosphate concentrations. Dogs with acute kidney injury had significantly higher IS levels (P <0.01) than those with chronic kidney diseases (CKD) (median [IQR] 57.7 (40.8) mg/L vs. 17.7 (25.1) mg/L). When CKD was graded using the International Renal Interest Society (IRIS) staging system, IS levels were correlated with CKD severity in both dogs and cats. The IS concentration is directly related to loss of renal function. Further studies are necessary to determine whether measurement of IS provides any additional diagnostic or prognostic information in dogs and cats with kidney disease.

Expression pattern analysis of hepatocellular carcinoma tumor markers in viral hepatitis B and C patients undergoing liver transplantation and resection

BACKGROUND

This study was conducted to compare the expression patterns of serum alpha-fetoprotein (AFP) and proteins induced by vitamin K absence or antagonist-II (PIVKA-II) in hepatocellular carcinoma (HCC) patients undergoing liver transplantation (LT) and resection at a high-volume single institution.

METHODS

First, 663 liver transplant recipients with HCC were selected. They were divided into hepatitis B virus (HBV) (n = 628) and hepatitis C virus (HCV) groups (n = 35). Their medical records were retrospectively reviewed. Second, another cohort of 2709 patients who underwent HCC resection included 2258 HBV, 143 HCV, and 308 non-HBV non-HCV (NBNC) patients.

RESULTS

In the transplantation group, pretransplantation AFP level >20 ng/mL was observed in 42.5% of HBV patients and 60% of HCV patients (P = .042). PIVKA-II level >40 mAU/mL was observed in 30.6% of HBV patients and 42.9% of HCV patients (P = .127). In the resection group, a preoperative AFP level >20 ng/mL was observed in 51.7% of HBV patients and 43.3% of HCV patients (P = .052). PIVKA-II level >40 mAU/mL was observed in 59.7% of HBV patients and 56.6% of HCV patients (P = .47). Preoperative AFP level >20 ng/mL and PIVKA-II level >40 mAU/mL were observed in 35.7% and 61% of NBNC patients, respectively. Receiver-operator characteristic curve analyses revealed that the expression pattern of PIVKA-II in patients with elevated AFP level was not predictable and vice versa, regardless of background liver diseases.

CONCLUSIONS

This study indicates that serum AFP and PIVKA-II may be expressed variably regardless of the types of background liver disease. Further large-volume multicenter studies are needed to evaluate the possibility of the etiology-dependent expression of tumor markers.

Innate memory T cells

Memory T cells are usually considered to be a feature of a successful immune response against a foreign antigen, and such cells can mediate potent immunity. However, in mice, alternative pathways have been described, through which naïve T cells can acquire the characteristics and functions of memory T cells without encountering specific foreign antigen or the typical signals required for conventional T cell differentiation. Such cells reflect a response to the internal rather the external environment, and hence such cells are called innate memory T cells. In this review, we describe how innate memory subsets were identified, the signals that induce their generation and their functional properties and potential role in the normal immune response. The existence of innate memory T cells in mice raises questions about whether parallel populations exist in humans, and we discuss the evidence for such populations during human T cell development and differentiation.

Risk factors for deterioration of nodular bronchiectatic Mycobacterium avium complex lung disease

SETTING The long-term natural course of Mycobacterium avium complex (MAC) disease with nodular bronchiectasis, the most common pulmonary non-tuberculous mycobacterial disease, is not well described.

OBJECTIVE

To identify risk factors for the deterioration of nodular bronchiectatic MAC lung disease over a 5-year follow-up period.

DESIGN

Clinical and laboratory data of 67 patients with nodular bronchiectatic MAC lung disease were collected. Chest computerised tomographic images were used to count the number of lung segments involved at diagnosis and measure subcutaneous fat thickness during follow-up.

RESULTS

The 34 patients who showed deterioration had significantly lower body mass index (BMI) (P = 0.004) and % predicted forced vital capacity (P = 0.032), higher numbers of lung segments involved (P < 0.001) and MAC-positive sputum cultures (P = 0.028), and thinner chest subcutaneous fat during follow-up (P < 0.001) than patients without deterioration. In particular, patients with both BMI <21.0 kg/m(2) and more than four lung segments involved had a 240-fold increased risk of deterioration (P < 0.001).

CONCLUSION

Patients with poor nutritional status and extensive lung involvement tend to experience deterioration of nodular bronchiectatic MAC lung disease.

Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies

BACKGROUND

The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors.

PATIENTS AND METHODS

Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing.

RESULTS

Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure.

CONCLUSION

OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored.

CLINICALTRIALSGOV IDENTIFIER

NCT01184807.

A case of idiopathic intracranial hypertension associated with PCOS

Idiopathic intracranial hypertension (IIH) is a rare neurologic disorder. It is also known as pseudotumor cerebri. The incidence of IIH is one to two per 100,000 population annually. The higher incidence is in obese women from 15 to 44 years. The main symptoms are headache and visual loss. It mostly affects women of childbearing age who are overweight or obese. There are many theories of pathogenesis of IIH, but precise pathogenesis is unknown. One of the causes of IIH is intracranial venous sinus thrombosis. It can cause increased cerebrospinal fluid (CSF) pressure by obstruction of venous outflow and blocking of CSF absorption. In polycystic ovary syndrome (PCOS) patients, thrombogenic tendency is increased due to increased aromatization of testosterone to estradiol which could induce estrogen-mediated thrombophilia. The authors present a 14-year-old girl with PCOS stigma who presented with a severe headache and papilledema. These symptoms were not improved by standard medical therapy of IIH and PCOS, but improved after laparoscopic ovarian drilling. The authors report it with a review of the literature.

Association of metabolic syndrome with coronary atherosclerosis in non-diabetic postmenopausal women

OBJECTIVE

We investigated the possible association of metabolic syndrome with arterial stiffness and coronary atherosclerosis in non-diabetic, postmenopausal women.

METHODS

A total of 293 non-diabetic, postmenopausal women who visited the health promotion center for a routine health check-up were included in a cross-sectional study. Arterial stiffness was measured by brachial-ankle pulse wave velocity, and coronary atherosclerosis was detected using 64-row multi-detector computed tomography.

RESULTS

Women with coronary atherosclerosis had a significantly higher proportion of metabolic syndrome than those without coronary atherosclerosis. The brachial-ankle pulse wave velocity was significantly higher in women who had metabolic syndrome compared to those who had no metabolic syndrome (1567.71 ± 211.81 vs. 1336.75 ± 159.62 cm/s, p < 0.001). In addition, the brachial-ankle pulse wave velocity was shown to increase with increasing number of metabolic syndrome components (p for trend < 0.001). Metabolic syndrome was associated with increased risk of coronary atherosclerosis (adjusted odds ratio 2.38; 95% confidence interval 1.01-5.06), after adjusting for confounding factors.

CONCLUSIONS

Metabolic syndrome increases the risk of coronary atherosclerosis in postmenopausal women. Increased arterial stiffness may partly explain an increased risk of coronary atherosclerosis in postmenopausal women with metabolic syndrome.

Role of AMP-activated protein kinase in cross-talk between apoptosis and autophagy in human colon cancer

Unresectable colorectal liver metastases remain a major unresolved issue and more effective novel regimens are urgently needed. While screening synergistic drug combinations for colon cancer therapy, we identified a novel multidrug treatment for colon cancer: chemotherapeutic agent melphalan in combination with proteasome inhibitor bortezomib and mTOR (mammalian target of rapamycin) inhibitor rapamycin. We investigated the mechanisms of synergistic antitumor efficacy during the multidrug treatment. All experiments were performed with highly metastatic human colon cancer CX-1 and HCT116 cells, and selected critical experiments were repeated with human colon cancer stem Tu-22 cells and mouse embryo fibroblast (MEF) cells. We used immunochemical techniques to investigate a cross-talk between apoptosis and autophagy during the multidrug treatment. We observed that melphalan triggered apoptosis, bortezomib induced apoptosis and autophagy, rapamycin caused autophagy and the combinatorial treatment-induced synergistic apoptosis, which was mediated through an increase in caspase activation. We also observed that mitochondrial dysfunction induced by the combination was linked with altered cellular metabolism, which induced adenosine monophosphate-activated protein kinase (AMPK) activation, resulting in Beclin-1 phosphorylated at Ser 93/96. Interestingly, Beclin-1 phosphorylated at Ser 93/96 is sufficient to induce Beclin-1 cleavage by caspase-8, which switches off autophagy to achieve the synergistic induction of apoptosis. Similar results were observed with the essential autophagy gene, autophagy-related protein 7, -deficient MEF cells. The multidrug treatment-induced Beclin-1 cleavage was abolished in Beclin-1 double-mutant (D133A/D146A) knock-in HCT116 cells, restoring the autophagy-promoting function of Beclin-1 and suppressing the apoptosis induced by the combination therapy. These observations identify a novel mechanism for AMPK-induced apoptosis through interplay between autophagy and apoptosis.

RAGE is essential for oncogenic KRAS-mediated hypoxic signaling in pancreatic cancer

A hypoxic tumor microenvironment is characteristic of many cancer types, including one of the most lethal, pancreatic cancer. We recently demonstrated that the receptor for advanced glycation end products (RAGE) has an important role in promoting the development of pancreatic cancer and attenuating the response to chemotherapy. We now demonstrate that binding of RAGE to oncogenic KRAS facilitates hypoxia-inducible factor 1 (HIF1)α activation and promotes pancreatic tumor growth under hypoxic conditions. Hypoxia induces NF-κB-dependent and HIF1α-independent RAGE expression in pancreatic tumor cells. Moreover, the interaction between RAGE and mutant KRAS increases under hypoxia, which in turn sustains KRAS signaling pathways (RAF-MEK-ERK and PI3K-AKT), facilitating stabilization and transcriptional activity of HIF1α. Knock down of RAGE in vitro inhibits KRAS signaling, promotes HIF1α degradation, and increases hypoxia-induced pancreatic tumor cell death. RAGE-deficient mice have impaired oncogenic KRAS-driven pancreatic tumor growth with significant downregulation of the HIF1α signaling pathway. Our results provide a novel mechanistic link between NF-κB, KRAS, and HIF1α, three potent molecular pathways in the cellular response to hypoxia during pancreatic tumor development and suggest alternatives for preventive and therapeutic strategies.

Characteristics of pleural effusions in systemic lupus erythematosus: differential diagnosis of lupus pleuritis

We investigated the clinical characteristics of pleural effusion in systemic lupus erythematosus (SLE). A prospective analysis of 17 SLE patients with pleural effusion (seven lupus pleuritis, eight transudative effusions and two parapneumonic effusions) was performed. Thirty non-SLE patients with pleural effusion were recruited as controls. A pleural fluid ANA titer ≥1:160 was found in 8/17 (47.1%) SLE patients and none of the 30 non-SLE patients (p = 0.0001). Pleural fluid to serum C3 ratios were significantly lower in SLE than in non-SLE (median (minimum-maximum) 0.29 (0.03-0.43) versus 0.52 (0.26-0.73), p = 0.0002). Among SLE patients, pleural fluid ANA titers ≥1:160 were more frequently found in patients with lupus pleuritis than in those with pleural effusion from causes other than lupus itself (85.7% versus 20.0%, p = 0.0152). Serum CRP levels were significantly increased in patients with lupus pleuritis compared with SLE patients with transudative pleural effusion (2.30 (0.30-5.66) versus 0.7 (0.12-1.47) mg/dl, p = 0.0062). In conclusion, pleural fluid ANA titer and serum CRP levels are significantly increased in lupus pleuritis.

Changes in high-density-lipoprotein cholesterol upon statin treatment in type 2 diabetic patients: a meta-analysis

BACKGROUND AND AIM

To investigate the diversity of change in high-density-lipoprote in cholesterol (HDL-C) after statin treatment in patients with type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

A systemic review searched for trials that reported a serum change in HDL-C in patients with T2DM after statin treatment, and extracted data for meta-analysis. Of 6709 articles surveyed, 160 articles were identified as eligible articles. In the analysis of simvastatin, serum HDL-C was increased in Non-Asian and Asian patients with T2DM by 2.17 mg/dl (95% CI 1.43 ∼ 2.90 mg/dl, p < 0.001) and 2.31 mg/dl (95% CI 1.37 ∼ 3.25 mg/dl, p < 0.001), respectively. In the analysis of atorvastatin, although significant, serum HDL-C was subtly increased in Non-Asian patients with T2DM by 1.14 mg/dl (95% CI 0.28 ∼ 2.01 mg/dl, p = 0.010) mg/dl; however, atorvastatin treatment did not significantly change the serum HDL-C by 0.12 mg/dl (95% CI -1.04 ∼ 1.27 mg/dl, p = 0.839) mg/dl in Asian patients with T2DM. According to meta-regression analysis, the baseline HDL-C did not affect the change in serum HDL-C in Asian patients with T2DM after either simvastatin or atorvastatin treatment. However, contrary to simvastatin, the coefficient of regression (r) showed a significant negative association (r = -0.18; 95% CI -0.32 to -0.04; p = 0.01) between baseline HDL-C and the change of HDL-C in non-Asian patients with T2DM after atorvastatin treatment.

CONCLUSION

We have demonstrated for the first time that there may be a discrepancy in the change of serum HDL-C in Asian patients with T2DM after atorvastatin treatment.

The association of radiographic progression with serum R-spondin 1 (RSPO1) levels or Dickkopf-1 (DKK1)/RSPO1 ratios in rheumatoid arthritis patients: clinical evidence for reciprocal inhibition between DKK1 and RSPO1

OBJECTIVES

To investigate the clinical implications of serum levels of R-spondin 1 (RSPO1), a natural antagonist for Dickkopf-1 (DKK1), and of DKK1/RSPO1 ratios in rheumatoid arthritis (RA) patients.

METHOD

Serum DKK1 and RSPO1 levels were measured in 102 RA patients and 39 age- and gender-matched healthy controls. In addition, DKK1 and RSPO1 levels were determined prior to and 3 months after anti-tumour necrosis factor alpha (anti-TNF-α) therapy in 15 RA patients. Clinical and laboratory data and baseline radiographs of the hands and feet were obtained. Serial radiographs were evaluated in 83 RA patients. Radiographic joint damage was assessed by the modified Sharp/van der Heijde score (SHS).

RESULTS

Serum RSPO1 levels were significantly reduced whereas serum DKK1 levels and DKK1/RSPO1 ratios were significantly increased in RA patients compared with controls (all p < 0.0001). Anti-TNF-α treatment significantly suppressed DKK1/RSPO1 ratios (p < 0.01). In contrast to DKK1 or RSPO1 levels, the ratios were significantly associated with erosive disease, elevated acute phase reactants, Disease Activity Score in 28 joints (DAS28) > 3.2, and radiographic progression rate (all p < 0.05). Although the RA patients with radiographic progression exhibited significantly increased DKK1 and reduced RSPO1 levels (p < 0.05), only the DKK1/RSPO1 ratio (log-transformed) was found to be a significant predictor of subsequent radiographic progression [odds ratio (OR) 2.07, p < 0.01].

CONCLUSIONS

In this study, the presence of RSPO1 in the circulation was shown for the first time. Our results suggest that the serum DKK1/RSPO1 ratio represents a better predictor of structural progression than either DKK1 or RSPO1 levels alone in RA patients.

Effects of dietary levels of glycine, threonine and protein on threonine efficiency and threonine dehydrogenase activity in hepatic mitochondria of chicks

This study was carried out to evaluate the relationship between threonine (Thr) efficiency and Thr dehydrogenase (TDG) activity as an indicator of Thr oxidation on chicks fed with levels of diets (CP [17.5% and 21.5%] and Thr [3.8 and 4.7 g/100 g CP]; glycine [Gly][0.64% and 0.98%] and true digestible Thr [dThr] [0.45% and 0.60%]). Calculation of the Thr efficiency was based on N-balance data and an exponential N-utilization model, and TDG activity was determined as accumulation of aminoacetone and Gly during incubation of hepatic mitochondria. This study found that in the liver of chicks who received a diet containing up to 0.79% Thr (4.7 g Thr/100 g of CP) in the 17.5% CP diet, no significant (p>0.05) effect on TDG activity was observed. However, significantly (p = 0.014) increased TDG activity was observed with a diet containing 21.5% CP (4.7 g Thr/100 g of CP) and the efficiency of Thr utilization showed a significant (p = 0.001) decrease, indicating the end of the Thr limiting range. No significant (p>0.05) effect on the total TDG activity and accumulation of Gly was observed with addition of Gly to a diet containing 0.45% dThr. In addition, addition of Gly to a diet containing 0.60% dThr also did not result in a change in accumulation of Gly. Due to an increase in accumulation of aminoacetone, an elevated effect on total TDG activity was also observed. No significant (p>0.05) reduction in the efficiency of Thr utilization was observed after addition of Gly at the level of 0.45% dThr. However, significantly (p<0.001) reduced efficiency of Thr utilization was observed after addition of Gly at the level of 0.60% dThr. Collectively, we found that TDG was stimulated not only by addition of Thr and protein to the diet, but also by addition of Gly, and efficiency of Thr utilization was favorably affected by addition of Gly at the level near to the optimal Thr concentration. In addition, no metabolic requirement of Gly through the TDG pathway was observed with almost the same accumulation of Gly and a slight increase in TDG activity by addition of Gly. Thus, our findings suggest that determination of TDG activity and parameter of efficiency of Thr utilization may be useful for evaluation of dietary Thr level.

The effectiveness of a brochure describing an acceptable method of sputum collection for tuberculosis testing

We evaluated the effectiveness of an educational brochure explaining proper sputum collection techniques for tuberculosis (TB) diagnosis. Patients with suspected pulmonary TB (PTB) were randomly assigned to either the brochure-using group or the non-using group. No significant difference in positive TB culture rates was observed between the brochure-using and non-using groups (33.1% vs. 35.6%, P = 0.690). The proportions of acceptable specimen samples for bacterial pneumonia were also similar between the two groups (37.1% vs. 35.6%). An educational brochure provided by the attending physician explaining an acceptable specimen collection method for TB testing did not result in a higher detection rate of PTB.

Evaluation of In-Stent Restenosis After Stent Implantation in the Vertebral Artery Ostium by Multislice Computed Tomography Angiography: Factors Affecting Accurate Diagnosis

PURPOSE

Few articles have evaluated vertebral artery ostium stents using multislice computed tomography (CT). The purpose of our study was to evaluate the diagnostic performance of 64- and 16-slice CT for detecting significant in-stent restenosis after vertebral artery ostium stenting, and to identify factors affecting the accurate diagnosis by CT.

METHODS

We reviewed 57 stents scanned using 64-slice CT and 34 stents using 16-slice CT. The accuracy of CT for diagnosing significant in-stent restenosis (≥ 50% diameter narrowing) was calculated using conventional angiography as a reference standard. Possible factors influencing the diagnostic performance of CT were analyzed, such as CT scanner, image quality, and stent characteristics.

RESULTS

With 64-slice CT, 46 (80.7%) of 57 stents were classified as evaluable, while with 16-slice CT, 28 (82.3%) of 34 stents were classified as evaluable. No stents with diameters ≤ 2.75 mm were evaluable. The respective results for 64- versus 16-slice CT were sensitivity 87.5% (95% confidence interval [CI] 47.3-99.7%) versus 100% (95% CI 15.8-100.0%), specificity 94.7% (95% CI 82.3%-99.4%) versus 96.2% (95% CI 80.4-99.9%). Factors reducing the accurate diagnosis were those associated with poor image quality, a diameter ≤ 2.75 mm, and drug-eluting stent type (p < 0.05).

CONCLUSIONS

64-slice and 16-slice CT scans are adequate in stents with diameters > 2.75 mm for the evaluation of in-stent restenosis after stent implantation in the vertebral artery ostium.

Rapamycin-enhanced mitomycin C-induced apoptotic death is mediated through the S6K1-Bad-Bak pathway in peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) is the most common secondary cancerous disease, and more effective novel regimens are needed. In this study, we identified a novel combination treatment for PC, chemotherapeutic agent mitomycin C in combination with mTOR (mammalian target of rapamycin) inhibitor rapamycin. We observed that the combination of mitomycin C and rapamycin induced synergistic cytotoxicity and apoptosis, which was mediated through an increase in caspase activation. The combination of mitomycin C and rapamycin inactivated p70 S6 ribosomal kinase (S6K1) and dephosphorylated Bad, leading to dissociation of Bcl-xL from Bak, which resulted in Bak oligomerization, mitochondria dysfunction and cytochrome c release. PF-4708671, a S6K1-specific inhibitor, enhanced the combination treatment-induced apoptosis, whereas S6K1 E389 DeltaCT-HA (S6K1 active form) dramatically decreased the induction of apoptosis. In addition, the combination treatment significantly inhibited LS174T intraperitoneal tumor growth in vivo. This study provides a preclinical rationale for apoptosis induction linked with the mTOR pathway through a combination of chemotherapeutic agents and mTOR inhibitor, and will support this combinatorial strategy to PC patients.

Effect of triceps surae and quadriceps muscle fatigue on the mechanics of landing in stepping down in ongoing gait

The aim of this study was to evaluate the effects of muscle fatigue of triceps surae and quadriceps muscles in stepping down in ongoing gait. We expected that the subjects would compensate for muscle fatigue to prevent potential loss of balance in stepping down. A total of 10 young participants walked over a walkway at a self-selected velocity to step down a height difference of 10-cm halfway. Five trials were performed before and after a muscle fatigue protocol. Participants performed two fatigue protocols: one for ankle muscle fatigue and another for knee muscle fatigue. Kinematics of and ground reaction forces on the leading leg were recorded. Fatigue did not cause a change in the frequency of heel or toe landing. Our results indicate that in stepping down fatigue effects are compensated by redistributing work to unfatigued muscle groups and by gait changes aimed at enhancing balance control, which was however only partially successful.

Fabrication of GaAs/Al0.3Ga0.7As multiple quantum well nanostructures on (100) si substrate using a 1-nm InAs relief layer

Nanometer scale thin InAs layer has been incorporated between Si (100) substrate and GaAs/Al0.3Ga0.7As multiple quantum well (MQW) nanostructure in order to reduce the defects generation during the growth of GaAs buffer layer on Si substrate. Observations based on atomic force microscopy (AFM) and transmission electron microscopy (TEM) suggest that initiation and propagation of defect at the Si/GaAs interface could be suppressed by incorporating thin (1 nm in thickness) InAs layer. Consequently, the microstructure and resulting optical properties improved as compared to the MQW structure formed directly on Si substrate without the InAs layer. It was also observed that there exists some limit to the desirable thickness of the InAs layer since the MQW structure having thicker InAs layer (4 nm-thick) showed deteriorated properties.

Long-term metformin use reduces gastric cancer risk in type 2 diabetics without insulin treatment: a nationwide cohort study

BACKGROUND

Metformin use has been associated with a decreased incidence and mortality of various cancers.

AIM

To evaluate the association between metformin use and gastric cancer.

METHODS

We randomly selected 100 000 type 2 diabetic patients from the 2004 Korean National Health Insurance claim database, and assessed gastric cancer incidence among 39 989 patients (aged 30-97 years) who were regularly treated with anti-diabetic drugs and followed-up from 2004 to 2010. In total, 26 690 patients had used metformin out of 32 978 diabetics who had not regularly used insulin (insulin non-users), and 5855 patients had used metformin out of 7011 regular insulin users.

RESULTS

Patients who used metformin showed a lower incidence of gastric cancer than those who did not use metformin, in insulin non-users (P = 0.047, log-rank test). However, in patients on regular insulin, there was no difference of gastric cancer incidence according to metformin use. In insulin non-users, the adjusted hazard ratio (AHR) for metformin use was 0.73 (95% confidential interval [CI], 0.53-1.01) with borderline statistical significance (P = 0.059). Duration of metformin use was associated with the reduction in gastric cancer risk (AHR, 0.88; 95% CI 0.81-0.96, P = 0.003), especially in patients who used metformin for more than 3 years (AHR, 0.57; 95% CI, 0.37-0.87; P = 0.009).

CONCLUSION

Metformin use >3 years in type 2 diabetics who do not use insulin is associated with a significantly reduced gastric cancer risk.

Effect of growth temperature and quantum structure on InAs/GaAs quantum dot solar cell

InGaAs-capped InAs quantum dots (QDs) and InAs QDs were adopted for the study of the effects through growth temperature and the band structure of InAs QDs on the performance of GaAs-based QD solar cell. It has been shown that the defects due to low temperature growth resulted in the decrease of Voc, Jsc and external quantum efficiency for GaAs bulk solar cell and QD embedded solar cells. It has been also found that InAs QDs act as defects by trapping photo-generated carries which affect the carrier transport in QD solar cell. The QD solar cell with InGaAs-capped InAs QDs showed higher performance than the QD solar cell with only InAs QDs. Such result has been explained by photo-generated carrier trapping and tunneling through InGaAs QW state in InGaAs-capped InAs QDs.

Vertical growth of core-shell III-V nanowires for solar cells application

High density (In)GaAs/GaAs/AIGaAs nanowires (NWs) consisting of n-type core and p-type shell have been vertically grown on (111) GaAs substrate using metal organic chemical vapor deposition (MOCVD) and fabricated into solar cells. Au colloidal nanoparticles (NPs) are employed as a catalyst. High density nanowires were obtained by uniform distribution of Au NPs. Fe-SEM, TEM and HRTEM images show that the morphology of shell is sensitive to p-doping concentration. Increase in the density of p-doping precursor results in "kinking" of NPs and rough shell surface. The origin of kinking has been explained by the GaAs twin phases due to Zn segregation on the surface of shell. It has been observed that the morphology of NPs can be controlled through optimizing various source purge technique of DEZn and deposition temperature. Electrical properties of core-shell doped NWs are carried out using I-V characterization. The core-shell NWs show characteristics of p-n junction as revealed by I-V studies.

Effects of longitudinal baffles on particles settling in a sedimentation basin

This study was conducted to evaluate the effects of longitudinal baffles on particles settling performance within a full-scale sedimentation basin with a flow rate of 1,000 m(3)/hr. Comparative experiments on turbidity removal efficiency and sludge deposit distribution were performed in longitudinally baffled and non-baffled sedimentation basins. The turbidity removal rate in the baffled sedimentation basin was observed to be higher than that in the non-baffled basin. In addition, the depth of the sludge deposit in the baffled sedimentation basin was approximately 20% less than that in the non-baffled sedimentation basin, and the sludge concentration was 10% higher. To explain these results and to further investigate the effects of longitudinal baffles, the authors performed computational fluid dynamics (CFD) simulation for both basin types. The results of this CFD simulation indicated that the flow, particularly near the outlet orifice, was more stable in the longitudinally baffled sedimentation basin. Moreover, it could be concluded that the longitudinal baffle enables a fully developed flow and is thus more effective for sedimentation.