Crystalline amorphous semiconductor superlattice

A new class of superlattice, crystalline amorphous superlattice (CASL), by alternatively depositing two semiconductor materials, is proposed. CASL displays three states depending on the component materials' phase: both polycrystalline phases, both amorphous phases, and one polycrystalline phase while another amorphous phase. Using materials capable of reversible phase transition, CASL can demonstrate reversibility among three states. GeTe/Sb(2)Te(3) CASL has been synthesized and proved by x-ray reflectometry and TEM results. The reversible transition among three states induced by electrical and laser pulse was observed. The changes in the optical absorption edge, electrical resistivity, thermal conductivity, and crystallization temperature as a function of layer thickness are interpreted as quantum or nanoeffects. The unique properties of CASL enable the design of materials with specific properties.

Diet-induced central obesity and insulin resistance in rabbits

The present study was designed to examine whether rabbits fed a diet containing high fat and sucrose could develop obesity and insulin resistance (IR), the major pathophysiological features of metabolic syndrome. Male Japanese white rabbits were fed either a normal chow diet (control) or high fat and sucrose diet (HFSD) for 36 weeks. Plasma levels of triglycerides (TG), total cholesterol (TC), glucose and insulin were measured. To evaluate glucose metabolism, we performed an intravenous glucose tolerance test. In addition, we compared adipose tissue accumulation in HFSD-fed rabbits with that in normal rabbits. HFSD constantly and significantly led to an increase in body weight of HFSD-fed rabbits, caused by significantly higher visceral adipose tissue accumulation. Although there were no differences in plasma TG, TC, glucose, insulin levels and blood pressure between the two groups, HFSD-fed rabbits showed impaired glucose clearance associated with higher levels of insulin secretion compared to control rabbits. Our results showed that HFSD induced IR and increased adipose accumulation in rabbits, suggesting that HFSD-fed rabbits may become a model for research on human IR and obesity.

Phenotypic analysis of Dlx5 overexpression in post-natal bone

Dlx5 plays an important role in the embryonic development of mineralized tissues. We hypothesized that Dlx5 also functions in regulating post-natal bone formation in mice. To prove this hypothesis, we infected 5-day-old bone sialoprotein (BSP)/avian retroviral receptor gene (TVA) transgenic mice with replication-competent retroviral vectors expressing wild-type Dlx5 (RCAS-Dlx5WT) and mutated Dlx5 at arginine (R) 31 of its homeodomain (RCAS-Dlx5RH). Immunohistochemistry indicated that RCAS-Dlx5WT increased BSP and osteopontin (OPN) expression, whereas it decreased that of osteocalcin (OC). RCAS-Dlx5RH mediated opposite effects. Semi-quantitative RT-PCR confirmed these results. Ex vivo overexpression of RCAS-Dlx5WT in BSP/TVA calvarial cells promoted, whereas that of RCAS-Dlx5RH inhibited, mineralized nodule formation as compared with that in control cells. Our results suggest that Dlx5 promotes expression of early markers of osteogenic differentiation and increases mineralization post-natally.

Leptin increases in Vogt-Koyanagi-Harada (VKH) disease and promotes cell proliferation and inflammatory cytokine secretion

BACKGROUND/AIMS

[corrected] Leptin has recently been found to play an important role in the development of autoimmune diseases. Our study is designed to investigate the expression and possible role of leptin in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease, one of the common types of autoimmune uveitis in China.

METHODS

Leptin levels in serums of 20 active, 16 inactive VKH patients and 20 healthy controls were measured using ELISA. Peripheral blood mononuclear cells (PBMCs) separated from active VKH patients and healthy controls were cultured with recombinant human leptin, and cell proliferation was assayed by [(3)H]-TdR incorporation. Cytokine levels in the supernatant of PBMCs cultured in mixed lymphocyte reaction (MLR) upon stimulation with leptin were assayed by ELISA.

RESULTS

Our results showed that leptin was significantly increased in the serum of active VKH patients compared with that in inactive VKH patients and healthy controls. Leptin levels in active VKH patients remained markedly higher when divided by body mass index (BMI). PBMCs cultured with leptin induced a marked cell proliferation and profound secretion of IFN-gamma and IL-17.

CONCLUSION

These findings suggest that leptin may be involved in the development of VKH disease possibly by promoting an immune response.

Polymorphisms in the cardiac sodium channel promoter displaying variant in vitro expression activity

Variable transcription of the cardiac sodium channel gene is a candidate mechanism determining arrhythmia susceptibility. We have previously cloned and characterized the core promoter and flanking region of SCN5A, encoding the cardiac sodium channel. Loss-of-function mutations in this gene have been reported in approximately 20% of patients with Brugada syndrome, an inherited cardiac electrical disorder associated with a high incidence of life-threatening arrhythmias. In this study, we identified DNA variants in the proximal 2.8 kb promoter region of SCN5A and determined their frequency in 1,121 subjects. This population consisted of 88 Brugada syndrome patients with no SCN5A coding region mutation, and 1,033 anonymized subjects from various ethnicities. Variant promoter activity was assayed in CHO cells and neonatal cardiomyocytes by transient transfection of promoter-reporter constructs. Single-nucleotide polymorphisms (SNPs) were identified at approximately 1/200 base pairs which are: 11 in the 5'-flanking region, 1 in exon 1, and 5 in intron 1. In addition, a haplotype consisting of two SNPs in complete linkage disequilibrium was identified. Minor allele frequencies were >5% in at least one ethnic panel at 5/19 polymorphic sites. In vitro functional analysis in cardiomyocytes identified four variants with significantly (P<0.05) reduced reporter activity (up to 63% reduction). The largest changes were seen with c.-225-1790 G>A, which reduced reporter activity by 62.8% in CHO cells and 55% in cardiomyocytes. From these results, we can conclude that the SCN5A core promoter includes multiple DNA polymorphisms with altered in vitro activity, further supporting the concept of interindividual variability in transcription of this cardiac ion channel gene.

Dietary fish oil and pectin enhance colonocyte apoptosis in part through suppression of PPARdelta/PGE2 and elevation of PGE3

We have shown that dietary fish oil and pectin (FP) protects against radiation-enhanced colon cancer by upregulating apoptosis in colonic mucosa. To investigate the mechanism of action, we provided rats (n = 40) with diets containing the combination of FP or corn oil and cellulose (CC) prior to exposure to 1 Gy, 1 GeV/nucleon Fe-ion. All rats were injected with a colon-specific carcinogen, azoxymethane (AOM; 15 mg/kg), 10 and 17 days after irradiation. Levels of colonocyte apoptosis, prostaglandin E(2) (PGE(2)), PGE(3), microsomal prostaglandin E synthase-2 (mPGES-2), total beta-catenin, nuclear beta-catenin staining (%) and peroxisome proliferator-activated receptor delta (PPARdelta) expression were quantified 31 weeks after the last AOM injection. FP induced a higher (P < 0.01) apoptotic index in both treatment groups, which was associated with suppression (P < 0.05) of antiapoptotic mediators in the cyclooxygenase (COX) pathway (mPGES-2 and PGE(2)) and the Wnt/beta-catenin pathway [total beta-catenin and nuclear beta-catenin staining (%); P < 0.01] compared with the CC diet. Downregulation of COX and Wnt/beta-catenin pathways was associated with a concurrent suppression (P < 0.05) of PPARdelta levels in FP-fed rats. In addition, colonic mucosa from FP animals contained (P < 0.05) a proapoptotic, eicosapentaenoic acid-derived COX metabolite, PGE(3). These results indicate that FP enhances colonocyte apoptosis in AOM-alone and irradiated AOM rats, in part through the suppression of PPARdelta and PGE(2) and elevation of PGE(3). These data suggest that the dietary FP combination may be used as a possible countermeasure to colon carcinogenesis, as apoptosis is enhanced even when colonocytes are exposed to radiation and/or an alkylating agent.

Aqueous flare and cells in Fuchs syndrome

PURPOSE

To quantitatively evaluate aqueous flare and cells in patients with Fuchs syndrome.

METHODS

The medical records of 40 patients (47 eyes) diagnosed with Fuchs syndrome between February 2006 and January 2007 at the Uveitis Study Center of Sun Yat-sen University were retrospectively reviewed. Aqueous flare and cells were clinically evaluated and quantified with laser flare-cell meter. Statistical analysis was performed to investigate the relationship between flare values and cell counts, and clinical parameters including patients' age, sex, duration of disease, best-corrected visual acuity, keratic precipitate, iris depigmentation, intraocular pressure, and posterior subcapsular lens opacities.

RESULTS

Aqueous flare values (photon counts/ms) were significantly higher in Fuchs syndrome (9.40+/-5.85) than in normal controls (5.77+/-1.89, P=0.000). Aqueous cell counts (cells/0.5 mm(3)) were also significantly higher in Fuchs syndrome (5.09+/-4.84) than in normal controls (1.14+/-1.03, P=0.000). The flare values were positively correlated with the cell counts (r=0.331, P=0.001). Both flare values and cell counts were higher in eyes with keratic precipitates scored 2+ or 3+ as compared to those with a 1+ score. Higher flare values and cell counts were also observed in eyes with a 2+ or 3+ iris depigmentation score as compared to those with a 1+ score. No difference was found between flare values and cell counts and other parameters.

CONCLUSION

Breakdown of blood-aqueous barriers and increased cell counts are present in the affected eyes in patients with Fuchs syndrome. These changes are positively associated with the degree of keratic precipitates and iris depigmentation.

Longitudinal quantification of aqueous flare and cells in Vogt-Koyanagi-Harada disease

AIMS

To quantitatively evaluate the changes of aqueous flare and cells in eyes with Vogt-Koyanagi-Harada (VKH) disease.

METHODS

This prospective study included 35 initial-onset VKH patients (70 eyes) and 46 recurrent VKH patients (92 eyes) following immunotherapy. Aqueous flare and cells were quantified using the laser flare-cell meter before treatment, 2 weeks, 1, 3, 6 and 9 months after treatment.

RESULTS

Before treatment, mean aqueous flare (ph/ms) in initial-onset and recurrent VKH eyes were 8.1 (SD 4.1) vs 43.6 (20.7) (p = 0.000). Following treatment, recurrent VKH eyes showed a significantly higher flare value than initial-onset VKH eyes at 2 weeks, 1, 3 and 6 months. Prior to treatment, mean cell counts (cells/0.5 mm3) in initial-onset and recurrent VKH eyes were 2.0 (1.9) vs 39.4 (23.1) (p = 0.000). Following treatment, recurrent VKH eyes showed significantly higher cell counts than initial-onset VKH eyes at 2 weeks, 1 and 3 months.

CONCLUSIONS

Our study shows that recurrent VKH patients displayed a more striking and long-lasting breakdown of the BAB and more severe inflammation than initial-onset VKH patients. Our study also indicates that the disruption of BAB lasted longer than aqueous cells either in initial-onset or in recurrent VKH patients.

Gemcitabine plus conventional-dose epirubicin versus gemcitabine plus cisplatin as first-line chemotherapy for stage IIIB/IV non-small cell lung carcinoma: A randomized phase II trial

18072

Background: Epirubicin is active for treatment of non-small cell lung carcinoma (NSCLC) but its optimal dose was undetermined. This study was designed to evaluate the efficacy and safety of gemcitabine plus conventional-dose epirubicin for stage IIIB/IV NSCLC. Methods: Patients with histological or cytological diagnosis of stage IIIB/IV NSCLC who had not received prior chemotherapy were eligible. Patients were randomized to GE (gemcitabine, 1,000 mg/m2 on days 1, 8, and 15 and epirubicin, 70 mg/m2 on day 15) or GC (gemcitabine, 1,000 mg/m2 on days 1, 8, and 15 and cisplatin, 80 mg/m2 on day 15). Treatment cycles were repeated every 4 weeks. Objective tumor response and toxicity were evaluated by using the World Health Organization criteria. Results: No significant difference in baseline characteristics between patients randomized to GC (n=41) and GE (n=39) arms were found. The objective response rate was 31.0% (95% C.I. 16.4% to 45.5) for GC and 37.2.0% (95% C.I. 22.2% to 52.3%) for GE. The median time-to-treatment-failure and overall survival were 6.1 months (95% C.I. 4.9 to 7.4 months) and 13.2 months (95% C.I. 8.9 to 17.5 months) for GC and 6.2 months (95% C.I. 5.2 to 7.2 months) and 21.2 months (95% C.I. 14.6 to 27.8 months) for GE, respectively. More grade 3/4 neutropenia (71.8%) was noted in GE than in GC (43.9%). Febrile neutropenia was also more common in GE (4 patients) than in GC (1 patient). However, delay of protocol treatment due to leukopenia was similar between the 2 arms. Data on the expresssion of the excission repair cross-complimentation 1 (ERCC1), evaluated by immunohistochemical study for patients with available tumor tissue, will be presented. Conclusions: Gemcitabine plus conventional-dose epirubicin is an effective and well-tolerated regimen for patients with stage IIIB/IV NSCLC.

No significant financial relationships to disclose.

Extent of nodal dissection and patient age impact recurrence-free survival (RFS) after surgery for non-small cell lung cancer (NSCLC)

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Background: Factors influencing the pattern of disease relapse after curative surgical resection in early stage NSCLC is unknown. We sought to evaluate the effect of tumor- and patient-related characteristics on the pattern of disease recurrence (local relapse and/or metastatic disease) and survival in relation to surgical resection for NSCLC. Methods: A consecutive retrospective series of 488 patients seen at Mayo Clinic Rochester who had complete resection of NSCLC between 1997 and 1998 was utilized. Cox proportional hazards model was used to evaluate the effect of age, gender, smoking status, TNM stage, number of lymph node (LN) involved, number of LN resected, and histopathologic diagnosis on RFS. Logistic regression was used to evaluate the effect on recurrence or death within the first 2 years after surgical resection. Results: Data on 342 patients with a median follow-up of 85 months (range: 0.1 to 162) are reported. 60% were male, and 81% had N0 stage at diagnosis. There were 26 (7.6%) never smokers. Median number of LN resected was 20 (interquartile range [IQR]: 14–29). Median age at surgery was 71 years (IQR: 64 to 76). A bi-modal pattern of local recurrence (N=62) after surgery for early stage NSCLC was observed, with 57% of patients having a local recurrence within 2 years and 21% of patients having a local recurrence from 5–7 years post-surgery. The median duration from surgery to first documented recurrence was 16 months (IQR: 8 to 39). While age, N stage, number of LN involved, and T stage were significant predictors of RFS univariately, only lesser LN resected (p=0.008), older age (p<0.0001) and higher T-stage (p=0.003) were significant adverse predictors of RFS in the multivariate analysis when adjusted for all factors. Higher T-Stage was associated with a significantly increased risk of recurrence or death within the first 2 years after surgical resection (p =0.004). Updated results using data from all 488 patients will be presented in the meeting. Conclusions: A trend towards a bimodal distribution of local recurrences after surgical resection of early stage NSCLC was observed. Increased number of LN resected, younger age and lower T stage were associated with better RFS.

No significant financial relationships to disclose.

Glutathione pathway genes predict quality of life (QOL) in lung cancer patients: A NCCTG-97–24–51 based study

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Background: Platinum compounds are major chemotherapeutic agents in lung cancer and are metabolized by the glutathione pathway enzymes. We reported that genotypes of glutathione-related enzymes, especially GCLC, may be host factors in predicting survival of patients with stage IIIB/IV non-small cell lung cancer who were stable or responding from prior platinum-based chemotherapy (Yang et al., ASCO 2006). NCCTG investigators previously correlated allelic variants in 5-FU metabolizing genes with QOL in colorectal cancer patients (Sloan et al., ASCO 2004). We sought to evaluate the role of glutathione pathway genotypes on QOL. Methods: DNA samples were analyzed using 6 polymorphic DNA markers in the glutathione metabolic pathway. The contrasting genotypes in the analysis were GSTM1 and GSTT1 (null vs. present), GSTP1-I105V (AA vs. GA/GG), GSTP1-A114V (CC vs. CT/TT), GPX1 (CC vs. TT/TC), and GCLC (homozygous repeat 77 vs. heterozygous 7*). Forty-six patients completed the FACT-L and the UNISCALE QOL questionnaires at baseline and week-8, and we have results for all 6 genotypes. A clinically significant decline (CSD) in QOL was defined as a 10% decrease from baseline to week-8. A multivariate logistic regression model was used to evaluate the association of all 6 genotypes with a CSD in QOL. Results: Patients carrying the GPX1-CC genotype had a CSD in the UNISCALE (Odds Ratio (OR): 10.0; p=0.02), total FACT-L score (OR: 7.9; p=0.03), the FACT-L physical well being construct (OR: 13.7; p=0.02), and the FACT-L functional well being construct (OR: 5.3; p=0.05). Other constructs, i.e., emotional, social and family, and additional concerns were not significantly associated with the genotypes. Conclusions: Genotypes of glutathione-related enzymes, especially GPX1 may be inherited factors in predicting patients’ QOL after platinum-based chemotherapy. Further investigation to define and measure the direct or indirect effects of these genes on QOL is critical, particularly, via drug responses, toxicities, and disease recurrence. (This work was partly supported by NIH grants CA77118, CA80127, and CA84354.)

No significant financial relationships to disclose.

Investigation of Key Parameters in SAGD Wellbore Design and Operation

Abstract

A simulation study was carried out to evaluate the impact of wellbore pressure drops and subcool control on SAGD reservoir performance using a three-dimensional fully coupled reservoir/wellbore model. This work builds on several concepts introduced by others and attempts to provide a method to evaluate these concepts and the relationships between them.

The results indicated a significant impact on steam chamber conformance, productivity and SOR at various operating pressures due to wellbore pressure drops. Pressure profiles within the injection and production wells were transferred into the reservoir, skewing the predominantly gravity drainage process. The chamber shape and conformance influence performance as it relates to subcool control. Sensitivities were run to evaluate the impact of key parameters.

This paper highlights some critical factors that affect SAGD performance and behaviour. Potential mitigating measures are introduced, such as liner and tubing design, variable perforations and injection ports, along with practical operating implications of each. The impacts of the findings on artificial lift selection and operation are discussed with regard to subcool control and net positive suction head available (HPSH). Potential implications to low pressure (LP-SAGD) operations are also considered in that light.

Introduction

It is generally accepted that optimal SAGD performance requires control of produced fluids to some subcool value so that a liquid level is maintained above the production well. This liquid level reduces the tendency for steam to flow directly into the production well liner, which ensures that steam is used efficiently in the SAGD process. However, too much liquid accumulation can reduce productivity, primarily due to a lower fluid temperature and corresponding higher fluid viscosity at the drainage faces and at the critical points of convergence to the production liner.

Optimum performance of the SAGD process can be defined for each project and reservoir type, however optimization is generally based on bitumen production rate (CDOR) and steam-to-oil ratio (SOR), often with conflicting imperatives.

One critical parameter in this optimization is subcool. Nasr's work indicates that there is no appreciable difference in CDOR between 5 ° and 30 °C of subcool for two-dimensional models (Tawfik Nasr, Alberta Research Council, Personal Communication, February 2005). However, Ito and Suzuki(1) demonstrated that the optimum SOR for the Hangingstone reservoir occurs at subcool ranges of between 30 ° and 40 °C with reasonable productivity. Edmunds(2) indicated that 20 ° to 30 °C subcool was a reasonable operating target for the 2D cases. However, he discussed the real world complications of the three-dimensional case in some detail as well.

Edmunds' work hinted that localized variability in subcool would occur, so that control of production rates to some optimum mixed or average subcool would result in steam production at some points along the liner, and large liquid level accumulations at other points. This is primarily due to the fact that the flow capacity of the wellbores is much greater than that of the reservoir in the same direction, making compensating steam movements in the reservoir difficult. Also, local liquid levels cannot effectively drain parallel to the well due to the very low drainage angles(2).

Meta- and pooled analysis of GSTT1 and lung cancer: a HuGE-GSEC review

Lung cancer is the most common malignancy in the Western world, and the main risk factor is tobacco smoking. Polymorphisms in metabolic genes may modulate the risk associated with environmental factors. The glutathione S-transferase theta 1 gene (GSTT1) is a particularly attractive candidate for lung cancer susceptibility because of its involvement in the metabolism of polycyclic aromatic hydrocarbons found in tobacco smoke and of other chemicals, pesticides, and industrial solvents. The frequency of the GSTT1 null genotype is lower among Caucasians (10-20%) than among Asians (50-60%). The authors present a meta- and a pooled analysis of case-control, genotype-based studies that examined the association between GSTT1 and lung cancer (34 studies, 7,629 cases and 10,087 controls for the meta-analysis; 34 studies, 7,044 cases and 10,000 controls for the pooled analysis). No association was observed between GSTT1 deletion and lung cancer for Caucasians (odds ratio (OR) = 0.99, 95% confidence interval (CI): 0.87, 1.12); for Asians, a positive association was found (OR = 1.28, 95% CI: 1.10, 1.49). In the pooled analysis, the odds ratios were not significant for either Asians (OR = 0.97, 95% CI: 0.83, 1.13) or Caucasians (OR = 1.09, 95% CI: 0.99, 1.21). No significant interaction was observed between GSTT1 and smoking on lung cancer, whereas GSTT1 appeared to modulate occupational-related lung cancer.

Proteomic analysis of hypoxia-induced responses in the syncytialization of human placental cell line BeWo

Syncytiotrophoblast formation is affected by a number of pathological conditions and suppressed syncytiotrophoblast formation due to hypoxia may play a role in the pathogenesis of preeclampsia. However, the molecular basis of hypoxia-inhibited trophoblast syncytialization is poorly understood. To determine the effect of hypoxia on trophoblast syncytialization, a proteomic analysis was performed in the human cytotrophoblast cell line BeWo using two-dimensional electrophoresis and MALDI-TOF-TOF-MS. Hypoxia induced marked inhibition of BeWo cell fusion and differentiation. The proteomic profiling was established under hypoxia in BeWo cell syncytialization. The results showed that twenty proteins were significantly up-or down-regulated under hypoxia, compared with cells under normoxia. In response to hypoxia, three antioxidants, peroxiredoxin 1, peroxiredoxin 2 and 1-Cys peroxiredoxin, were down-regulated, two proteins involved in glycolysis pathway (malate dehydrogenase and enolase) were up-regulated. The expression of two members of the annexin family (annexin A2 and annexin A5) increased. We also found a decreased expression of 14-3-3 tau protein in hypoxia treated cells. Proteins implied in protein degradation and folding were also identified. The expression of two cytoskeleton components (keratin 1 and beta-actin) was found to be down-regulated. In addition, galectin-3 was up-regulated. These proteins have been implicated in regulating cellular oxidative stress, glycolysis, signal transduction, protein folding and degradation, cell mobility and cytoskeletal structure formation. Western blot analysis revealed that the levels of peroxiredoxin 1 and 14-3-3 tau decreased, whereas the levels of annexin A5 and annexin A2 increased in BeWo cells under hypoxia. These findings provided new insights into the molecular mechanisms in mediating cellular response to hypoxia in trophoblast syncytialization.

Phenotype of genetically regulated thymic involution in young BXD RI strains of mice

Age-related thymic involution is a multifactorial process related to age-related changes in intrathymic T-cell development and cytokines. In contrast, early thymic involution, because of genetic differences that cause rapid or slow thymic involution at younger age, is less well characterized. Here, we analysed three representative rapid-involuting strains of mice, BXD 8, 18 and 32, compared with three representative slow-involuting strains, BXD 9, 19 and 29, all at 2 months of age. In rapid-involuting strains compared with slow involution strains, thymocyte production, as indicated by CD4+ and CD8+ T-cell receptor recombination excision circle (TREC), were decreased. Rapid-involution strains of mice exhibited a developmental block at the DN1 to DN2 and CD4-CD8- (DN) to CD4+CD8+ (double positive, DP) transition stages. There was also increased susceptibility to H2O2-induced apoptosis, decreased thymic expression of IL-7, decreased expression of an IL-7 downstream anti-apoptosis gene, Bcl-2, and increased expression of a pro-apoptotic gene, Bad. In contrast, IL-7R expression was higher on DN thymocytes of rapid-involution strains. The increased expression of IL-7R was associated with an increased thymocyte proliferation in response to anti-CD3 + IL-7 or anti-CD3 + IL-12 + IL-7. These findings indicate that, even at young age, genetic differences of IL-7/IL-7R regulation pathway in BXD strains of mice can lead to characteristic phenotypic changes that have been previously associated with age-related thymic involution.