Electronic structure and magnetic properties of penta-graphene nanoribbons

Calculations predict that bipolar magnetic semiconductor and half-metal behaviors can be observed in penta-graphene nanoribbons.

Long noncoding RNA, tissue differentiation-inducing nonprotein coding RNA is upregulated and promotes development of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the major causes of cancer death worldwide, especially in Eastern Asia. Due to the poor prognosis, it is necessary to further dissect the underlying mechanisms and explore therapeutic targets of ESCC. Recently, studies show that long noncoding RNAs (lncRNAs) have critical roles in diverse biological processes, including tumorigenesis. Increasing evidence indicates that some lncRNAs are widely involved in the development and progression of ESCC, such as HOTAIR, SPRY4-IT1 and POU3F3. An emerging lncRNA, tissue differentiation-inducing nonprotein coding RNA (TINCR), has been studied in human cutaneous squamous cell carcinoma and has critical biological function, but its role in ESCC remains unknown. Here, we evaluated the expression profile of TINCR and its biological function in ESCC. In a cohort of 56 patients, TINCR was significantly overexpressed in ESCC tissues compared with paired adjacent normal tissues. Further, in vitro silencing TINCR via small interfering RNA (siRNA) inhibited the proliferation, migration and invasion of ESCC cells. Meantime, siRNA treatment induced apoptosis and blocked the progression of cell cycle. Taken together, our study suggests that TINCR promotes proliferation, migration and invasion of ESCC cells, acting as a potential oncogene of ESCC.

[Interleukin-20 and interleukin-22 in pleural effusion]

OBJECTIVE

To investigate the concentrations and clinical significance of interleukin (IL)-20 and IL-22 in pleural effusion with various etiologies.

METHODS

Pleural effusion (PE) and corresponding serum samples were obtained from 88 patients from Wuhan Tuberculosis Prevention and Control Institute from June 2011 to June 2013. There were 27 cases with malignant pleural effusion, 24 with tuberculous pleural effusion, 17 with bacterial pleural effusion and 20 with transudativeeffusion. The pleural and serum levels of IL-20 and IL-22 were determined by sandwich enzyme-linked immunosorbent assays (ELISA).

RESULTS

(1) Except for transudativeeffusion, the concentration of IL-20 in malignant pleural effusion (36.8±5.1) ng/L, tuberculous pleural effusion (34.8±6) ng/L, bacterial pleural effusion (41.7±20.2) ng/L, were significantly higher than that of the corresponding serum concentration (29.7±5.97) ng/L, (27.3 ±6.7) ng/L, (25.6±4.7) ng/L (t=5.044, 3.804, 3.452, P<0.05). However, the concentration of IL-20 in pleural effusions of different causes showed no significant difference; malignant (36.8±5.1) ng/L, tuberculous(34.8±6.0) ng/L, bacterial (41.7±20.2) ng/L, transudate (34.1±7.3) ng/L (P>0.05). The concentration of IL-22 (median, quartiles) in tuberculouseffusion was 146.1 (39.8) ng/L and bacterial effusion 59.6 (484.3) ng/L was significantly higher than those in the corresponding serum concentrations 18.7 (9.8) ng/L, 15.7 (17.2) ng/L (Z value respectively -3.971, -3.290, P<0.05). The concentration of IL-22 in tuberculous pleural effusion, bacterial pleural effusion, transudative pleural effusion was significant higher than those in malignant pleural effusion respectively (all P<0.001). (2)The concentrations of IL-22 in malignant pleural effusion was correlated positively with those in serum (r=0.729, P<0.001). (3) With a cut-off value of 19.7 ng/L, pleural IL-22 exhibited a high sensitivity and specificity of 95.1% (39/41) and 88.9%(24/27) respectively, when used for distinguishing infectious pleural effusion (including tuberculous and bacterial effusion) from malignant pleural effusion (P<0.001).

CONCLUSIONS

Higher levels of IL-22 in tuberculous and bacterial pleural effusion were found when compared with corresponding serum levels and might be involved in the pathogenesis of infectious pleural effusion. Pleural IL-22 measurement provided reliable diagnostic efficiency for distinguishing infectious from malignant pleural effusion.

Liraglutide ameliorates non-alcoholic fatty liver disease by enhancing mitochondrial architecture and promoting autophagy through the SIRT1/SIRT3-FOXO3a pathway

AIM

Overwhelming oxidative stress is implicated as crucial in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Liraglutide, a well-established antidiabetes drug, was recently reported to ameliorate NAFLD with an elusive mechanism. We used a mouse model to examine whether liraglutide could ameliorate NAFLD and explored the possible mechanisms.

METHODS

Twenty C57BL/6J mice were randomly treated with a normal-fat diet or high-fat diet for 16 weeks, then further distributed into four groups and subjected to s.c. injection of liraglutide or saline for 4 weeks. The growth/metabolism, oxidative stress, mitochondrial architecture and autophagy were assessed prospectively at the 20th week.

RESULTS

High-fat diet inducement resulted in severe NAFLD while liraglutide treatment significantly reversed the trend, marked by reduced bodyweight, improved glucose tolerance and liver triglyceride composition. Reduced hepatic malondialdehyde level, increased mRNA and protein levels of CATALASE and MNSOD indicated liraglutide affected both the oxidative and antioxidative process to ameliorate oxidative stress. After liraglutide administration, the upregulated mRNA and protein levels of mitochondrial fission and fusion-related DRP1, OPA1 and respiratory chain-related COMPLEX1, UCP2 demonstrated the enhancement of mitochondrial architecture which may attenuate the generation of reactive oxygen species (ROS), while the diminished mRNA and protein level of P62 and increased levels of Beclin1 and LC3II/I ratio indicated the promoting autophagy, which probably contribute to the ROS elimination. Further, restored protein levels of Sirtuin1/Sirtuin3 and the downstream p-FOXO3a reveal the probable pathways of liraglutide acting on autophagy.

CONCLUSION

Liraglutide diminishes oxidative stress by enhancing mitochondrial architecture and promoting autophagy through the SIRT1/SIRT3-FOXO3a-LC3 pathway to ameliorate diet-induced NAFLD.

Application of BOLD Magnetic Resonance Imaging for Evaluating Regional Volumetric Foot Tissue Oxygenation: A Feasibility Study in Healthy Volunteers

OBJECTIVE/BACKGROUND

To evaluate the feasibility and repeatability of applying blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in the feet to quantify regional dynamic changes in tissue oxygenation during proximal cuff occlusion and reactive hyperemia.

METHODS

Ten healthy male subjects underwent BOLD and T1-weighted imaging of the feet on two separate occasions, using a 3-T scanner. Dynamic changes in BOLD signal intensity were assessed before and during proximal cuff occlusion of the thigh and during reactive hyperemia, and BOLD time course data were evaluated for the time-to-half ischemic minimum, minimum ischemic value, peak hyperemic value, time-to-peak hyperemia, time-to-half peak hyperemia, and end value. T1-weighted images were used for segmentation of volumes of interest (VOI) in anatomical regions of the foot (heel, toes, dorsal foot, medial and lateral plantar foot). Repeatability of vascular responses was assessed for each foot VOI using semiautomated image registration and quantification of serial BOLD images.

RESULTS

The heel VOI demonstrated a significantly higher peak hyperemic response, expressed as percent change from baseline BOLD signal intensity, compared with all other VOIs of the foot (heel, 7.4 ± 1.2%; toes, 5.6 ± 0.8%; dorsal foot, 5.7 ± 1.6%; medial plantar, 5.6 ± 1.7%; lateral plantar, 5.6 ± 1.5% [p < .05]). Additionally, the lateral plantar VOI had a significantly lower terminal signal intensity value (i.e., end value) when compared with all foot VOIs (p < .05). BOLD MRI was repeatable between visits in all foot VOIs, with no significant differences between study visits for any of the evaluated functional indices.

CONCLUSION

BOLD MRI offers a repeatable technique for volumetric assessment of regional foot tissue oxygenation. Future application of BOLD imaging in the feet of patients with peripheral vascular disease may permit serial evaluation of regional tissue oxygenation and allow for improved assessment of therapeutic interventions targeting specific sites of the foot.

Polarization-independent plasmonic subtractive color filtering in ultrathin Ag nanodisks with high transmission

We demonstrate a TE/TM polarization-independent plasmonic subtractive color filtering scheme employing ultrathin two-dimensional Ag nanodisks. These TE/TM polarization-independent subtractive color filters exhibit small feature sizes (below 200 nm) and high transmission up to 70% in the visible spectral region, superior to previously reported plasmonic color filters. Simulated optical transmission spectra and colors are in good agreement with experimental results. The color-filtering behaviors strongly depend on thickness and period of nanodisks. Underlying mechanisms are also discussed in detail.

Endurance exercise ameliorates low birthweight developed catch-up growth related metabolic dysfunctions in a mouse model

Low birthweight is known to predict high risk of metabolic diseases in adulthood, while regular endurance exercises are believed sufficient to improve metabolic dysfunction. In this study, we established a mouse model to determine whether long-term exercise training could ameliorate catch-up growth, and we explored the possible underlying mechanisms. By restricting maternal food intake during the last week of gestation, we successfully produced low birthweight pups. Further, normal birthweight mice and low birthweight mice were randomly distributed into one of three groups receiving either a normal fat diet, high fat diet, or high fat diet with exercise training. The growth/metabolism, mitochondrial content and functions were assessed at 6 months of age. Through group comparisons and correlation analyses, the 4th week was demonstrated to be the period of crucial growth and chosen to be the precise point of intervention, as the growth rate at this point is significantly correlated with body weight, intraperitoneal glucose tolerance test (IPGTT), Lee's index and fat mass in adulthood. In addition, regular endurance exercises when started from 4 weeks remarkably ameliorated low birthweight outcomes and induced catch-up growth and glucose intolerance in the 25th week. Furthermore, real-time PCR and western blot results indicated that the effect of long-term exercise on mitochondrial functions alleviated catch-up related metabolic dysfunction. To conclude, long-term exercise training from the 4th week is sufficient to ameliorate catch-up growth and related metabolic disturbances in adulthood by promoting mitochondrial functions in skeletal muscle.

Gender-related affecting factors of prediabetes on its 10-year outcome

OBJECTIVE

To investigate the gender-related affecting factors of prediabetes on its 10-year outcome, in a longitudinal study.

METHODS AND RESULTS

This longitudinal population-based study was performed in the Ping Liang community, Yangpu district, Shanghai, between November 2002 and October 2014. There were 334 participants with prediabetes enrolled in the final analysis. While a certain proportion of the prediabetic population progress to diabetes, the majority remain at the same level or even revert to normal glucose regulation. No gender difference was observed in the change of glucose regulation. However, results from an adjusted logistic regression analysis in males showed that physical activity was significantly associated with both elevated odds of reverting to normal glucose regulation (active vs inactive, OR 3.00, 95% CI 1.09 to 8.30) and developing diabetes (OR 0.34, 95% CI 0.13 to 0.92). Age, baseline 2 h glucose, triglycerides and smoking status were also risk factors significantly associated with diabetes development; while for females, waist circumference played a key role in the outcome. Every unit elevation of waist circumference was associated with lower odds of reverting to normal glucose regulation (OR, 0.94; 95% CI 0.89 to 0.98) and higher odds of progressing to diabetes (OR, 1.05; 95% CI 1.01 to 1.10). Baseline hypertension and family history of diabetes carried higher risk for developing diabetes as well.

CONCLUSIONS

Physical activity in males and waist circumference in females are important factors predicting both progression to diabetes and regression to normal glucose regulation, indicating that more exercise for males and lower waist circumference for females are beneficial for prediabetes to achieve reversion.

Developmental expression and function analysis of protein tyrosine phosphatase receptor type D in oligodendrocyte myelination

Receptor protein tyrosine phosphatases (RPTPs) are extensively expressed in the central nervous system (CNS), and have distinct spatial and temporal patterns in different cell types during development. Previous studies have demonstrated possible roles for RPTPs in axon outgrowth, guidance, and synaptogenesis. In the present study, our results revealed that protein tyrosine phosphatase, receptor type D (PTPRD) was initially expressed in mature neurons in embryonic CNS, and later in oligodendroglial cells at postnatal stages when oligodendrocytes undergo active axonal myelination process. In PTPRD mutants, oligodendrocyte differentiation was normal and a transient myelination delay occurred at early postnatal stages, indicating the contribution of PTPRD to the initiation of axonal myelination. Our results also showed that the remyelination process was not affected in the absence of PTPRD function after a cuprizone-induced demyelination in adult animals.

miRNAs are required for the terminal differentiation of white matter astrocytes in the developing CNS

While the regulation of the neurogenesis and oligodendrogenesis by microRNAs has been intensively studied, little is known about the role of microRNAs (miRNAs) in the development of astrocytes. Here, we report that microRNAs play an essential role in the differentiation and maturation of white matter astrocytes in mouse spinal cord tissues. In glial fibrillary acidic protein (GFAP)/Dicer conditional mutants, the initial generation of astrocyte progenitor cells was normal in the spinal cord. However, there was a much reduced number of GFAP+ astrocytes with shorter processes in the white matter of mutant tissues. In contrast, the expression of gray matter protoplasmic astrocyte marker was not affected. Together, our studies indicated that miRNAs are required for the differentiation and morphological maturation of white matter fibrous astrocytes in the developing spinal cord.

A multi-method review of home-based chemotherapy

This study summarises research- and practice-based evidence on home-based chemotherapy, and explores existing delivery models. A three-pronged investigation was conducted consisting of a literature review and synthesis of 54 papers, a review of seven home-based chemotherapy programmes spanning four countries, and two case studies within the Canadian province of Ontario. The results support the provision of home-based chemotherapy as a safe and patient-centred alternative to hospital- and outpatient-based service. This paper consolidates information on home-based chemotherapy programmes including services and drugs offered, patient eligibility criteria, patient views and experiences, delivery structures and processes, and common challenges. Fourteen recommendations are also provided for improving the delivery of chemotherapy in patients' homes by prioritising patient-centredness, provider training and teamwork, safety and quality of care, and programme management. The results of this study can be used to inform the development of an evidence-informed model for the delivery of chemotherapy and related care, such as symptom management, in patients' homes.

A novel lncRNA, LUADT1, promotes lung adenocarcinoma proliferation via the epigenetic suppression of p27

Long noncoding RNAs (lncRNAs) are known to regulate the development and progression of various cancers. However, few lncRNAs have been well characterized in lung adenocarcinoma (LUAD). Here, we identified the expression profile of lncRNAs and protein-coding genes via microarrays analysis of paired LUAD tissues and adjacent non-tumor tissues from five female non-smokes with LUAD. A total of 498 lncRNAs and 1691 protein-coding genes were differentially expressed between LUAD tissues and paired adjacent normal tissues. A novel lncRNA, LUAD transcript 1 (LUADT1), which is highly expressed in LUAD and correlates with T stage, was characterized. Both in vitro and in vivo data showed that LUADT1 knockdown significantly inhibited proliferation of LUAD cells and induced cell cycle arrest at the G0–G1 phase. Further analysis indicated that LUADT1 may regulate cell cycle progression by epigenetically inhibiting the expression of p27. RNA immunoprecipitation and chromatin immunoprecipitation assays confirmed that LUADT1 binds to SUZ12, a core component of polycomb repressive complex 2, and mediates the trimethylation of H3K27 at the promoter region of p27. The negative correlation between LUADT1 and p27 expression was confirmed in LUAD tissue samples. These data suggested that a set of lncRNAs and protein-coding genes were differentially expressed in LUAD. LUADT1 is an oncogenic lncRNA that regulates LUAD progression, suggesting that dysregulated lncRNAs may serve as key regulatory factors in LUAD progression.

Effects of prediabetes mellitus alone or plus hypertension on subsequent occurrence of cardiovascular disease and diabetes mellitus: longitudinal study

Whether prediabetes mellitus alone or combined with other disorders means a higher risk for cardiovascular disease (CVD) is still controversial. This study aimed to investigate the association between prediabetes mellitus and CVD and diabetes mellitus and to explore whether prediabetes mellitus alone or combined with other syndromes, such as hypertension, could promote CVD risks significantly. This longitudinal population-based study of 1609 residents from Shanghai in Southern China was conducted between 2002 and 2014. Participants with a history of CVD at baseline were excluded from analysis. Multivariate log-binomial regression models were used to adjust possible coexisting factors. Incidence of CVD during follow-up was 10.1%. After adjusting for age, sex, and other factors, the association between prediabetes mellitus and CVD was not observed. When hypertension was incorporated in stratifying factors, adjusted CVD risk was elevated significantly (odds ratio, 2.41; 95% confidence interval, 1.25-4.64) in prediabetes mellitus and hypertension combined group, and coexistence of diabetes mellitus and hypertension made CVD risk highly significantly increased, reaching 3.43-fold higher than the reference group. Blood glucose level within prediabetic range is significantly associated with elevated risks for diabetes mellitus after multivariable adjustment, but only when it is concurrent with other disorders, such as hypertension, it will significantly increase CVD risk.

Gpr177-mediated Wnt Signaling is Required for Fungiform Placode Initiation

Fungiform papillae are formed as patterned rows on the surface of the anterior tongue at early organogenesis and contain one taste bud in each papilla to form one of the important sensory organs. Despite the essential role of Wnt/β-catenin signaling in controlling the development of fungiform taste papillae, the universal function of Wnt ligands in the initiation of the fungiform placode has not been completely elucidated. Here, by Shh (Cre) -mediated oral epithelial deletion of Wntless (Gpr177), a regulator essential for intracellular Wnt trafficking, we demonstrate that an overall function of Wnts is required for initiation of the fungiform placode. Multiple Wnts are expressed in the tongue epithelium at E11.5 before initiation of the fungiform placodes. Epithelial Gpr177 loss-of-function, associated with reduction of canonical Wnt signaling in lingual epithelium as exhibited by a loss of TopGal activity and Axin2 expression, results in the failure of fungiform placode initiation, as assessed by diminished expression of several taste placode molecular markers. Moreover, LiCl treatment of Gpr177 epithelial-deficient tongue explants at E11.5, but not at E12.5, restores tongue placode formation, demonstrating that Wnt ligands in the tongue surface prior to but not after fungiform placode initiation are responsible for fungiform papilla initiation. Epithelium-specific expression of an active β-catenin in the Gpr177-deficient tongue leads to fungiform papillae generation, suggesting that an intra-epithelial response to Wnts is required for placode initiation. Together, these results suggest that Gpr177 controls epithelial initiation of the fungiform placode through signaling via epithelial Wnt ligands.

Protective effects of pioglitazone against immunoglobulin deposition on heart of streptozotocin-induced diabetic rats

AIM

Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists have immunomodulatory and anti-inflammatory effects. The study investigated the autoimmune injuries of diabetic cardiomyopathy (DCM) and tested the hypothesis that PPAR-γ agonists suppress disordered immune responses in diabetic heart, thereby preventing evolution of DCM.

METHODS

STZ-induced diabetic rats were assigned to five groups: DM group, given no treatment; INS group, given insulin (4 U kg(-1) d(-1)); PIL group, given low dose pioglitazone (4 mg kg(-1) d(-1)); PIL/INS group, given both low dose pioglitazone and insulin; PIH group, given high dose pioglitazone (20 mg kg(-1) d(-1)). Normal rats (CON group) were also monitored as control. The pathologic abnormalities of hearts were observed. The immunoglobulin deposition was examined by immunohistochemistry and immunofluorescence.

RESULTS

At 16 weeks, interstitial fibrosis was shown in diabetic heart which was accompanied by plenty of inflammatory cells infiltrated. Pioglitazone therapy could ameliorate the cardiac injuries. Shown by immunohistochemistry, the difference of integrated optical density (IOD) of immunoglobulin deposition among each group had statistic significance. No obvious immunoglobulins were deposited in the intercellular substance of heart in CON group (IgA 290.8 ± 88.1, IgG 960.4 ± 316.0 and IgM 341.3 ± 67.9). But the deposition of immunoglobulins increased significantly in DM group (IgA 7,047.5 ± 1,328.3, P < 0.05; IgG 28,945.9 ± 5,160.7, P < 0.05 and IgM 8,580.8 ± 1,336.8, P < 0.05). Administration of pioglitazone greatly reduced the increased deposition in a dose-dependent fashion. Moreover, the statistical significance was the same with immunofluorescence analysis as with immunohistochemical examination.

CONCLUSIONS

The data suggest that disordered immune responses play an important role in the pathogenesis of DCM. Pioglitazone showed protective effects by inhibiting the immunoglobulin deposition on diabetic myocardium.

Epitope specificity of cross-clade neutralizing sera from Chinese HIV-1-positive individuals

Induction of broadly neutralizing antibody is considered important for an effective HIV-1 vaccine. Identification and characterization of broadly neutralizing antibodies in HIV-1-infected patients will facilitate our understanding of the immune correlates to protection and the design of an effective prophylactic vaccine. A number of studies to probe the specificity of antibodies in broadly neutralizing sera in the United States and Europe have been reported. However, little is known about and would be interesting to investigate the immunological characteristics of HIV-1-positive sera in China where non-clade B viruses are prevalent and the circulating viral subtypes are distinct and more complex than both the United States and Europe. Here, we screened 80 Chinese HIV-1-positive sera against a minipanel of pseudoviruses representing various circulating HIV-1 subtypes in China and identified 8 cross-clade neutralizing sera (CNsera). Immunological characterization of the sera showed that gp120-targeting antibodies with multiple epitope specificities contributed to the cross-clade neutralizing activity of these CNsera. V3-directed antibodies were prevalent in these CNsera, but did not mainly contribute to their neutralization breath and potency while CD4bs-specific, 2F5- and 4E10-like antibodies were rarely detected. 2G12-like neutralizing antibodies were more frequently detected in HIV-1 patients from China where recombinant subtype viruses are prevalent than in United States and Europe. One broadly neutralizing serum (Serum 45) was identified to contain antibodies with unknown epitope specificities that were sensitive to terminal glycan modifications on virus Env and insensitive to N160K mutagenesis, and correlated with the cross-clade neutralization activity of Serum 45.

Dynamic expression of secreted Frizzled-related protein 3 (sFRP3) in the developing mouse spinal cord and dorsal root ganglia

Wnt proteins have been implicated in regulating a variety of developmental processes in the CNS. Secreted Frizzled-related protein 3 (sFRP3) is a member of the sFRP family that can inhibit the Wnt signaling by binding directly to Wnts via their regions of homology to the Wnt-binding domain of Frizzleds. Recent studies suggested that sFRP3 plays an important role in cell proliferation and differentiation in various tissues. To understand the role of sFRP3 in neural development, we carried out detailed studies on the expression of sFRP3 in the developing nervous system. Our results revealed that sFRP3 is initially expressed in the ventricular zone of the spinal cord and dorsal root ganglia (DRG), and later in the dorsal horn of spinal cord and subpopulation of DRG neurons. The spatiotemporally dynamic expression ofsFRP3 strongly suggests that sFRP3 has potential functions in the sensory neuron genesis and sensory circuitry formation.

Peer assisted learning in surgical skills laboratory training: a pilot study

BACKGROUND

Peer assisted learning (PAL) has been rarely investigated in surgical skills training.

AIMS

Describe feedback residents give peers on surgical skills with and without guidelines, determine the association between feedback and actual performance, evaluate resident satisfaction with PAL.

METHOD

Participants evaluated peers using a validated knot-tying checklist and provided feedback on suturing without a guideline. Feedback comments were coded by type and an expert scored performance of each participant. Residents completed a satisfaction questionnaire.

RESULTS

Comments were generally specific. Feedback was twice as likely with the use of a guideline. Specific feedback correlated significantly with expert knot-tying score but not suturing score. Most participants felt peer feedback was helpful and were motivated to practice surgical skills after PAL sessions.

CONCLUSIONS

Surgical residents can provide high quality specific feedback to peers on surgical skills using performance guidelines. Further exploration of effective PAL methodology in surgical skills laboratory training is needed.

Gemcitabine and capecitabine as third-line treatment in patients with metastatic colorectal cancer after failure of irinotecan and oxaliplatin

620

Background: There is no standard chemotherapeutic regimen for patients with advanced colorectal cancer (CRC) progressing after combination regimens including irinotecan and oxaliplatin and having good performance status. 5-FU and gemcitabine are synergistic in preclinical studies of colon cancer cells. And gemcitabine also increases intracellular release of 5-FU from capecitabine. The aim of this study is to evaluate the efficacy and tolerance of the gemcitabine/capecitabine combination as third-line treatment for patients with advanced colorectal cancer.

Methods: Between May 2007 and September 2009, the data on 12 patients with metastatic colorectal cancer after failure of irinotecan- and oxaliplatin-containing regimens reviewed retrospectively. The median patient age was 54.0 years (range 37-77). The ECOG performance status was 0, 1 or 2. All patients has 2 or more previous chemotherapy. Patients received GemCap regimen (oral capecitabine 1,000 mg/m2 twice daily on days 1 to 14 plus Gem 1,000 mg/m2 on days 1 and 8 every 3 weeks). Eleven patients were evaluable for the response and all patients were evaluable for toxicity.

Results: No partial response was achieved and disease stabilization in 4 (36.4.3%) cases. Median progression-free survival and median overall survival were 9.1 weeks (range 3.0-18.0) and 22.3 weeks (range 10.5- 53.0). Four patients with disease stabilization had longer median progression-free survival than those with disease progression (13 weeks vs. 6.2 weeks). No toxic deaths occurred. Grade 3 toxicities were thrombocytopenia (in 2 patients), neutropenia (in 2 patients) and mucositis (in 1 patient), hand-foot syndrome (in 1 patient) and GI toxicity (in 2 patients).

Conclusions: The combination of gemcitabine and capecitabine was found to be a safe palliative regimen for heavily pretreated patients with metastatic CRC. Despite no patients had radiologic response, patients with disease stabilization achieved better progression-free survival. This regimen seems to be potentially effective regimen in the treatment of CRC.

No significant financial relationships to disclose.

Synergistic antitumor effect of TRAIL and adriamycin on the human breast cancer cell line MCF-7

The aim of the present study was to determine the effect of the combination of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and adriamycin (ADM) on the human breast cancer cell line MCF-7 and to identify potential mechanisms of apoptosis. Cell viability was analyzed by the MTT assay and the synergistic effect was assessed by the Webb coefficient. Apoptosis was quantified using the annexin V-FITC and propidium iodide staining flow cytometry. The mRNA expression of TRAIL receptors was measured by RT-PCR. Changes in the quantities of Bax and caspase-9 proteins were determined by Western blot. MCF-7 cells were relatively resistant to TRAIL (IC50 >10 microg/mL), while MCF-7 cells were sensitive to ADM (IC50 <10 microg/mL). A subtoxic concentration of ADM (0.5 microg/mL) combined with 0.1, 1, or 10 microg/mL TRAIL had a synergistic cytotoxic effect on MCF-7 cells, which was more marked with the combination of TRAIL (0.1 microg/mL) and ADM (0.5 microg/mL). In addition, the combined treatment with TRAIL and ADM significantly increased cell apoptosis from 9.8% (TRAIL) or 17% (ADM) to 38.7%, resulting in a synergistic apoptotic effect, which is proposed to be mediated by up-regulation of DR4 and DR5 mRNA expression and increased expression of Bax and caspase-9 proteins. These results suggest that the combination of TRAIL and ADM might be a promising therapy for breast cancer.

PI3K Pathway Activation in Breast Cancer Is Associated with the Basal-Like Phenotype and Cancer-Specific Mortality

Background: Current biological therapies for breast cancer are tailored to steroid hormone (ER, PR) and HER2 receptor status. Understanding the biological basis of resistance to current targeted therapies and the identification of new potential therapeutic targets is an ongoing challenge. The PI3K pathway is altered in a high proportion of breast cancers and may be associated with specific phenotypes and therapeutic resistance. We undertook an integrative study of mutational, copy number and expression analysis of key regulators of the PI3K pathway in a cohort of 292 invasive breast cancer patients with known treatment outcomes.Material and Methods: Mutations in 3 "hotspots" in exons 9 and 20 of the PIK3CA gene were determined by sequencing and PIK3CA gene copy number by qPCR. PTEN loss and Akt activation i.e. pAkt (Ser473) were assessed by immunohistochemistry using tissue microarrays. Cores were scored by 2 independent observers blinded to clinicopathological data and patient outcome and a histoscore calculated by multiplying the percent positive cells and staining intensity in a range 0-3. Standard statistical tests were applied to assess relationship between the measured parameters and patient outcome.Results: Alterations identified included PIK3CA mutations (12/168 i.e. 7%), PIK3CA copy number gain (28/209 i.e. 14%), PTEN loss (73/258 i.e. 28%) and AKT activation (62/258 i.e. 24%). Overall at least one parameter was altered in 72% i.e. 139 of 193 assessable primary breast cancers. PI3K pathway activation was significantly associated with ER negative (P=0.0008) and PR negative (P=0.006) status, high tumor grade (P=0.032) and a "basal-like" phenotype (P=0.01), where 92% (25/27) of tumors had an altered pathway. In univariate analysis PI3K pathway aberrations were associated with death from breast cancer however this relationship was not maintained in multivariate analysis. No association was identified between an activated pathway and outcome in tamoxifen- or chemotherapy-treated patients.Discussion: We conclude that &gt;70% of breast cancers have an alteration in at least one component of the PI3K pathway and this might be exploited to therapeutic advantage especially in "basal-like" cancers.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2123.

Pancreatic perfusion of healthy individuals and type 1 diabetic patients as assessed by magnetic resonance perfusion imaging

AIMS/HYPOTHESIS

Loss of pancreatic beta cell mass and function leads to the development of diabetes mellitus. Currently there is no technical way to non-invasively image islet function and mass. Murine models suggest that islets are highly vascularised organs that make a significant contribution to the total pancreatic blood flow. The current study was undertaken to test with arterial spin labelling (ASL) magnetic resonance imaging if islet mass and/or stimulation of human pancreatic islets by hyperglycaemia can differentially increase whole-pancreas perfusion, thereby distinguishing non-diabetic from type 1 diabetic patients.

METHODS

We assessed pancreatic blood flow using ASL at baseline, during a hyperglycaemia clamp study (glucose at 11 mmol/l) and during recovery to euglycaemia.

RESULTS

Seventeen healthy volunteers and seven type 1 diabetic patients were studied. In healthy volunteers we observed no change in pancreatic blood flow during the three phases of the study. A trend for an increase in blood flow was observed in the two control tissues, the liver and kidney. Similarly, there was no significant difference in blood flow during the three stages (baseline, hyperglycaemia and recovery) in diabetic patients and there was no significant difference observed between diabetic patients and normal volunteers.

CONCLUSIONS/INTERPRETATION

Our data suggest that in humans neither increased demand nor islet mass has a substantial influence on pancreatic perfusion. It is possible, however, that the current state-of-the art imaging technology employed in this study might not be sensitive enough to distinguish between a true effect and noise.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00280085.

Phase II clinical trial of XELOX as first line treatment for patients with unresectable or metastatic gastric cancer

15062

Background: The survival of advanced gastric cancer remains poor, while no chemotherapy regimen was recognized standard. Oxaliplatin and Capecitabine (Xeloda) have demonstrated promising antitumor efficacy in advanced colorectal cancer. The present study was conducted to further evaluate the efficacy and safety of XELOX (Oxaliplatin and Xeloda) regimen in gastric cancer. Methods: Patients with unresectable or metastatic gastric cancer were enrolled into this study. They all receive the XELOX regimens (Oxaliplatin 130mg/ m2 intravenously in 2 hours on day 1 followed by oral capecitabine 1000mg/ m2 twice daily for 14 days every 3 weeks).We evaluated the response every 2 cycles. Results: The median age of the total enrolled 45 patients was 55 years (range, 22–82 years), including 32 male and 13 female. They received a median of 5 cycles (range, 2–8 cycles) of XELOX. 21 of 45 patients (46.7%) achieved an objective response, 1 patient (2.2%) had completed response. 17 patients (37.8%) experienced stable disease. Median time to tumor progression (TTP) and median overall survival were not available yet due to the further follow-up needed. Most toxicity events were mild to moderate in XELOX regimen, with grade 3/4 neutropenia of 8.9 %, thrombocytopenia of 6.7%, anemia of 11.1%, hand-foot syndrome of 6.7 % and diarrhea of 6.7 %. Grade 3 neuropathy was 4.4%. The patients with advanced gastric cancer had a good tolerance to this chemotherapy. Conclusions: XELOX is a highly effective first-line treatment for unrsectable and metastatic gastric cancer. The response rates in this trial seems to be similar to those observed with FU/leucovorin/oxaliplatin combinations. XELOX is tolerable well in the treatment of advanced gastric cancer.

No significant financial relationships to disclose.

Increased production of reactive oxygen species contributes to motor neuron death in a compression mouse model of spinal cord injury

STUDY DESIGN

Experimental laboratory investigation of the role and pathways of reactive oxygen species (ROS)-mediated motor neuron cell death in a mouse model of compression spinal cord injury.

OBJECTIVES

To analyze ROS-mediated oxidative stress propagation and signal transduction leading to motor neuron apoptosis induced by compression spinal cord injury.

SETTING

University of Louisville Health Science Center.

METHODS

Adult C57BL/6J mice and transgenic mice overexpressing SOD1 were severely lesioned at the lumbar region by compression spinal cord injury approach. Fluorescent oxidation, oxidative response gene expression and oxidative stress damage markers were used to assay spinal cord injury-mediated ROS generation and oxidative stress propagation. Biochemical and immunohistochemical analyses were applied to define the ROS-mediated motor neuron apoptosis resulted from compression spinal cord injury.

RESULTS

ROS production was shown to be elevated in the lesioned spinal cord as detected by fluorescent oxidation assays. The early oxidative stress response markers, NF-kappaB transcriptional activation and c-Fos gene expression, were significantly increased after spinal cord injury. Lipid peroxidation and nucleic acid oxidation were also elevated in the lesioned spinal cord and motor neurons. Cytochrome c release, caspase-3 activation and apoptotic cell death were increased in the spinal cord motor neuron cells after spinal cord injury. On the other hand, transgenic mice overexpressing SOD1 showed lower levels of steady-state ROS production and reduction of motor neuron apoptosis compared to that of control mice after spinal cord injury.

CONCLUSION

These data together provide direct evidence to demonstrate that the increased production of ROS is an early and likely causal event that contributes to the spinal cord motor neuron death following spinal cord injury. Thus, antioxidants/antioxidant enzyme intervention combined with other therapy may provide an effective approach to alleviate spinal cord injury-induced motor neuron damage and motor dysfunction.

Negative refraction at infrared wavelengths in a two-dimensional photonic crystal

We report on the first experimental evidence of negative refraction at telecommunication wavelengths by a two-dimensional photonic crystal field. Samples were fabricated by chemically assisted ion beam etching in the InP-based low-index constrast system. Experiments of beam imaging and light collection show light focusing by the photonic crystal field. Finite-difference time-domain simulations confirm that the observed focusing is due to negative refraction in the photonic crystal area.