CCCTC-binding factor mediates effects of glucose on beta cell survival

OBJECTIVES

Pancreatic islet β-cell survival is paramount for regulation of insulin activity and for maintaining glucose homeostasis. Recently, Pax6 has been shown to be essential for many vital functions in β-cells, although many molecular mechanisms of its homeostasis in β-cells remain unclear. The present study investigates novel effects of glucose- and insulin-induced CCCTC-binding factor (CTCF) activity on Pax6 gene expression as well as for subsequent effects of insulin-activated signalling pathways, on β-cell proliferation.

MATERIALS AND METHODS

Pancreatic β-TC-1-6 cells were cultured in DMEM and stimulated with high concentrations of glucose (5-125 mm); cell viability was assessed by MTT assay. Effects of CTCF on Pax6 were evaluated in the high glucose-induced environment and CTCF/Erk-suppressed cells, by promoter reporter and western blotting analyses.

RESULTS

Increases in glucose and insulin concentrations upregulated CTCF and consequently downregulated Pax6 in β-cell survival and proliferation. Knocking-down CTCF directly affected Pax6 transcription through CTCF binding and blocked the response to glucose. Altered Erk activity mediated effects of CTCF on controlling Pax6 expression, which partially regulated β-cell proliferation.

CONCLUSIONS

CTCF functioned as a molecular mediator between insulin-induced upstream Erk signalling and Pax6 expression in these pancreatic β-cells. This pathway may contribute to regulation of β-cell survival and proliferation.

Peliosis hepatis mimicking cancer: A case report

Peliosis hepatis (PH) is a rare condition characterized by the presence of blood-filled cavities within the liver. The etiology of PH remains unknown, but it has been reported to be associated with infections or malignancies. However, the cause of PH is not clear in 20–50% of patients. The current study presents the case of a 19-year-old male who presented with right upper quadrant pain that had lasted for three days. The patient was a student with no previous medical history. Contrast-enhanced computer tomography (CT) and ultrasonography showed a neoplasm in the right liver and a diagnosis of primary liver cancer was made due to the manifestation of the disease and the results of physical tests. The individual was treated successfully with an irregular right hemihepatectomy and was in good health at 6-months post-surgery. A tissue specimen was obtained and determined to be PH by pathological examination and immunohistochemistry analysis. Consequently, a diagnosis of PH must be considered in cases like this.

A novel strategy to evaluate the quality of traditional Chinese medicine based on the correlation analysis of chemical fingerprint and biological effect

A novel strategy was developed to assess the quality of TCM (traditional Chinese medicine) based on the correlation analysis of the chemical fingerprint and biological effect. Using Rehmanniae glutinosa (RG) to treat the kidney yin deficiency as an example, chemical fingerprints of 27 RG samples were analyzed by liquid chromatography-mass spectrometry (LC-MS), and urinary metabolic profiling of RG treatment of kidney yin deficiency in rats was explored by using LC-MS. A correlation analysis between the chemical fingerprints and efficacy evaluation was developed to identify quality marker components to assess TCM quality. Thirty-four variables in chemical fingerprints were successfully defined to have a close relationship with the efficacy of RG. The validation test with a new RG sample indicated that these efficacy-related components could be used to evaluate the integral quality of RG accurately. Compared with conventional chemical fingerprint methodology, not only is the proposed approach a powerful tool to identify efficacy-related components for the quality evaluation of TCM, but the approach can also be used to predict the therapeutic efficacy of TCMs.

Characterization of rheumatoid arthritis subtypes using symptom profiles, clinical chemistry and metabolomics measurements

OBJECTIVE

The aim is to characterize subgroups or phenotypes of rheumatoid arthritis (RA) patients using a systems biology approach. The discovery of subtypes of rheumatoid arthritis patients is an essential research area for the improvement of response to therapy and the development of personalized medicine strategies.

METHODS

In this study, 39 RA patients are phenotyped using clinical chemistry measurements, urine and plasma metabolomics analysis and symptom profiles. In addition, a Chinese medicine expert classified each RA patient as a Cold or Heat type according to Chinese medicine theory. Multivariate data analysis techniques are employed to detect and validate biochemical and symptom relationships with the classification.

RESULTS

The questionnaire items 'Red joints', 'Swollen joints', 'Warm joints' suggest differences in the level of inflammation between the groups although c-reactive protein (CRP) and rheumatoid factor (RHF) levels were equal. Multivariate analysis of the urine metabolomics data revealed that the levels of 11 acylcarnitines were lower in the Cold RA than in the Heat RA patients, suggesting differences in muscle breakdown. Additionally, higher dehydroepiandrosterone sulfate (DHEAS) levels in Heat patients compared to Cold patients were found suggesting that the Cold RA group has a more suppressed hypothalamic-pituitary-adrenal (HPA) axis function.

CONCLUSION

Significant and relevant biochemical differences are found between Cold and Heat RA patients. Differences in immune function, HPA axis involvement and muscle breakdown point towards opportunities to tailor disease management strategies to each of the subgroups RA patient.

A possible connection between adhesion regulating molecule 1 overexpression and nuclear factor kappa B activity in hepatocarcinogenesis

Adhesion regulating molecule 1 (ADRM1), a 19S proteasome cap-associated protein, and nuclear factor kappa B (NF-κB), a protein transcription factor controlling DNA transcription, may play an important role in tumorigenesis. Overexpression of ADRM1 and activation of NF-κB are well-observed in hepatocellular carcinoma (HCC). However, little is known about whether both are functionally connected during hepatocarcinogenesis, and the mechanisms involved. In this study, using laboratory techniques including short hairpin RNA (shRNA)-mediated knockdown, immunohistochemistry (IHC), both semi-quantitative and real-time RT-PCR, western blotting, MTT assay, transwell assay, flow cytometry and electrophoretic mobility shift assay (EMSA), the expression of ADRM1, the effects of ADRM1 knockdown on NF-κB activity, as well as the biological behavior of HCC cells including proliferation, migration, invasion and apoptosis were investigated in the samples from HCC patients and HCC cell lines. We found that both mRNA and protein levels of ADRM1 were increased in HCC tissues and that this increase in ADRM1 expression was parallel to the metastatic potential of HCC cell lines. After ADRM1 knockdown in MHCC97-H cells, the expression of IκB-α was increased and the NF-κB activity was reduced. Furthermore, ADRM1 knockdown inhibited MHCC97-H cell proliferation and induced cell apoptosis, and the migration and invasion of MHCC97-H cells were significantly repressed. These results indicate that there is a clear functional connection between ADRM1 and NF-κB in hepatocarcinogenesis, despite the precise mechanisms through which the two work together still being unknown.

Decoupled circular-polarized dual-head volume coil pair for studying two interacting human brains with dyadic fMRI

A major function of the human brain is to mediate interactions with other people. Until recently, studying social interactions as they occur within the brain was not possible due to the lack of measurable methods to observe two interacting minds simultaneously. We have developed a novel MRI dual-head volume coil pair that can scan two subjects' brains simultaneously while the subjects are socially interacting in one MRI scanner. The feasibility of using this coil for dyadic functional MRI (fMRI) study has been successfully demonstrated for the first time. Meanwhile, an innovative robust scheme for decoupling two circular-polarized coils (not surface coils) is introduced in theory and validated in practice in the coil technology development.

Bone marrow-derived cell transplantation therapy for myocardial infarction: lessons learned and future questions

Over the last decade, many investigators have utilized bone marrow-derived cells for cell transplantation therapy in animal studies and in patients with acute myocardial infarction and chronic heart failure. In those experimental and clinical studies, various doses and types of bone marrow-derived cells have been transplanted to the injured myocardium using a variety of approaches, such as intracoronary infusion or catheter-based direct endomyocardial injection, and at different time points after successful coronary reperfusion. The reported treatment effects are variable, which may be related to differences in cell type and quantity of transplanted cells, timing and approach of cell transplantation and patient selection. In this review, we summarize and discuss the controversies and questions related to the clinical use of bone marrow-derived cells.

[Evaluation of the effect of the traditional Chinese medicine tongxinluo or ginseng on excess fatigue rats studied by metabonomics approach based on liquid chromatography-mass spectrometry]

Excess fatigue is a pathological state of continuing accumulation of fatigue, which may cause the deterioration of body health, occurrence of diseases, and even lead to death. A metabonomics study was performed on the excess fatigue rats treated with traditional Chinese medicine Tongxinluo or ginseng based on ultra fast liquid chromatography coupled with ion trap-time of flight mass spectrometry (UFLC-IT-TOF-MS). The plasma metabolic profiling data of the control rats, excess fatigue rats, and excess fatigue rats treated with Tongxinluo or ginseng were acquired. The orthogonal partial least squares analysis (OPLS) was applied for the multivariate statistics and the discovery of important differential metabolites distinguishing the excess fatigue rats treated with Tongxinluo or ginseng from the control rats and excess fatigue rats. The results showed tryptophan, bile acid, lysophosphatidylcholine metabolism were disturbed in the excess fatigue rats. The metabolic pattern including the related metabolic pathways of the rats, being treated with Tongxinluo or ginseng, was adjusted towards the normal state.

AUC-based biomarker ensemble with an application on gene scores predicting low bone mineral density

MOTIVATION

The area under the receiver operating characteristic (ROC) curve (AUC), long regarded as a 'golden' measure for the predictiveness of a continuous score, has propelled the need to develop AUC-based predictors. However, the AUC-based ensemble methods are rather scant, largely due to the fact that the associated objective function is neither continuous nor concave. Indeed, there is no reliable numerical algorithm identifying optimal combination of a set of biomarkers to maximize the AUC, especially when the number of biomarkers is large.

RESULTS

We have proposed a novel AUC-based statistical ensemble methods for combining multiple biomarkers to differentiate a binary response of interest. Specifically, we propose to replace the non-continuous and non-convex AUC objective function by a convex surrogate loss function, whose minimizer can be efficiently identified. With the established framework, the lasso and other regularization techniques enable feature selections. Extensive simulations have demonstrated the superiority of the new methods to the existing methods. The proposal has been applied to a gene expression dataset to construct gene expression scores to differentiate elderly women with low bone mineral density (BMD) and those with normal BMD. The AUCs of the resulting scores in the independent test dataset has been satisfactory.

CONCLUSION

Aiming for directly maximizing AUC, the proposed AUC-based ensemble method provides an efficient means of generating a stable combination of multiple biomarkers, which is especially useful under the high-dimensional settings.

CONTACT

lutian@stanford.edu.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Effect of the traditional Chinese medicine tongxinluo on endothelial dysfunction rats studied by using urinary metabonomics based on liquid chromatography-mass spectrometry

A urinary metabonomic method based on ultra-fast liquid chromatography coupled with ion trap-time of flight mass spectrometry (UFLC/MS-IT-TOF) was employed to study the preventive efficacy and the metabolic changes caused by simavastatin and the traditional Chinese medicine tongxinluo in endothelial dysfunction rats. Principal component analysis (PCA) was applied to study metabolic patterns of endothelial dysfunction rats and healthy control rats. 1-Methyladenosine, indoxyl sulfate, hippuric acid, riboflavin, coproporphyrin, and p-cresol glucuronide were identified as potential biomarkers, indicating that pathways of adenine, tryptophan, phenylalanine, riboflavin and porphyrin metabolism were disturbed in endothelial dysfunction rats. Applications of simvastatin and tongxinluo to endothelial dysfunction rats improved endothelial function according to the results of histopathology and measurements of endothelin-1 and nitric oxide. Metabonomic studies suggested that tongxinluo prevents endothelial dysfunction by regulating multiple metabolic pathways to their normal state, whereas simvastatin only altered selected metabolic pathways. This research demonstrated that metabonomics is a powerful and promising tool for disease investigation and the efficacy evaluation of complex traditional Chinese medicines.

CpG-island methylation study of liver fluke-related cholangiocarcinoma

BACKGROUND

Genetic changes have been widely reported in association with cholangiocarcinoma (CCA), while epigenetic changes are poorly characterised. We aimed to further evaluate CpG-island hypermethylation in CCA at candidate loci, which may have potential as diagnostic or prognostic biomarkers.

METHODS

We analysed methylation of 26 CpG-islands in 102 liver fluke related-CCA and 29 adjacent normal samples using methylation-specific PCR (MSP). Methylation of interest loci was confirmed using pyrosequencing and/or combined bisulfite restriction analysis, and protein expression by immunohistochemistry.

RESULTS

A number of CpG-islands (OPCML, SFRP1, HIC1, PTEN and DcR1) showed frequency of hypermethylation in >28% of CCA, but not adjacent normal tissues. The results showed that 91% of CCA were methylated in at least one CpG-island. The OPCML was the most frequently methylated locus (72.5%) and was more frequently methylated in less differentiated CCA. Patients with methylated DcR1 had significantly longer overall survival (Median; 41.7 vs 21.7 weeks, P=0.027). Low-protein expression was found in >70% of CCA with methylation of OPCML or DcR1.

CONCLUSION

Aberrant hypermethylation of certain loci is a common event in liver fluke-related CCA and may potentially contribute to cholangiocarcinogenesis. The OPCML and DcR1 might serve as methylation biomarkers in CCA that can be readily examined by MSP.

Initial experience in using continuous arterial spin-labeled MR imaging for early detection of Alzheimer disease

BACKGROUND AND PURPOSE

MR imaging of the brain has significant potential in the early detection of neurodegenerative disorders such as AD. The purpose of this work was to determine if perfusion MR imaging can be used to separate AD from normal cognition in individual subjects. We investigated the diagnostic utility of perfusion MR imaging for early detection of AD compared with structural imaging.

MATERIALS AND METHODS

Data were analyzed from 32 participants in the institutional review board-approved CHS-CS: 19 cognitively healthy individuals and 13 with clinically adjudicated AD. All subjects underwent structural T1-weighted SGPR and CASL MR imaging. Four readers with varying experience separately rated each CASL and SPGR scan finding as normal or abnormal on the basis of standardized qualitative diagnostic criteria for observed perfusion abnormalities on CASL or volume loss on SPGR and rated the confidence in their evaluation.

RESULTS

Inter-rater reliability was superior in CASL (kappa = 0.7 in experienced readers) compared with SPGR (kappa = 0.17). CASL MR imaging had the highest sensitivity (85%) and accuracy (70%). Frontal lobe CASL findings increased sensitivity to 88% and accuracy to 79%. Fifty-seven percent of false-positive readings with CASL were in controls with cognitive decline or instability within 5 years. Three of the 4 readers revealed a statistically significant relationship between confidence and correct classification when using CASL.

CONCLUSIONS

Readers were able to separate individuals with mild AD from those with normal cognition with high sensitivity by using CASL but not volumetric MR imaging. This initial experience suggests that CASL MR imaging may be a useful technique for detecting AD.

Cerebrospinal Fluid Cytology and Clinical Analysis of 34 Cases with Leptomeningeal Carcinomatosis

The clinical characteristics and cerebrospinal fluid (CSF) cytological features of 34 hospitalized patients with leptomeningeal carcinomatosis (LC) were studied. Most patients presented with signs of meningeal irritation (19 cases) and intra-cranial hypertension (23 cases). Computed tomography (CT) and/or magnetic resonance imaging (MRI) revealed brain parenchymal lesions, hydrocephalus and leptomeningeal enhancement (nine, six and eight cases, respectively). The CSF changes included high opening pressure (21 cases), increased white blood cell count (23 cases), elevated protein levels (25 cases) and low glucose levels (17 cases). Malignant cells were found in all CSF specimens and 32 cases had malignant cells in their initial CSF examinations. High serum levels of carcinoembryonic antigen (CEA) occurred in 11 patients. Signs of meningeal irritation and intra-cranial hypertension were common. It is concluded that serum CEA measurement along with CT and MRI scanning are helpful in the diagnosis of LC. Crucially, however, CSF cytology could be the most important technique for the diagnosis of LC.

The value, qualification, and regulatory use of surrogate end points in drug development

The acceptance and use of either surrogate end points (SEPs) or efficient clinical end points are associated with greater and more rapid availability of new medicines as compared with disease situations for which clinical end points are inefficient or no surrogates exist. This review of the history of the development, qualification, and acceptance of key SEPs shows that both successes and failures had three key characteristics: (i) apparent biologic plausibility, (ii) prognostic value for the outcome of the disease, and (iii) an association between changes in the SEP and changes in outcome with therapeutic intervention--the three factors recommended for SEPs in the International Conference on Harmonisation's "Statistical Principles for Clinical Trials." We recommend that only prognostic value be an absolute prerequisite for surrogacy, because therapeutic interventions may not exist a priori, and biological plausibility can be subjective. Ideally, all three of these factors would be traded off against one another in a consistent and transparent risk-management process.

Arsenic trioxide suppresses paclitaxel-induced mitotic arrest

OBJECTIVES

To understand if there exists a functional interaction between arsenic trioxide and paclitaxel in vitro.

MATERIALS AND METHODS

HeLa and HCT116 (rho53(+/+) and rho53(-/-)) cells were treated with As2O3 and/or paclitaxel for various times. Treated cells were collected for analyses using a combination of flow cytometry, fluorescence microscopy and Western blotting.

RESULTS

Because As(2)O(3) is capable of inhibiting tubulin polymerization and inducing mitotic arrest, we examined whether there existed any functional interaction between As(2)O(3) and paclitaxel, a well-known microtubule poison. Flow cytometry and fluorescence microscopy revealed that although As(2)O(3) alone caused a moderate level of mitotic arrest, it greatly attenuated paclitaxel-induced mitotic arrest in cells with p53 deficiency. Western blot analysis showed that As(2)O(3) significantly blocked phosphorylation of BubR1, Cdc20, and Cdc27 in cells treated with paclitaxel, suggesting that arsenic compromised the activation of the spindle checkpoint. Our further studies revealed that the attenuation of paclitaxel-induced mitotic arrest by As(2)O(3) resulted primarily from sluggish cell cycle progression at S phase but not enhanced mitotic exit.

CONCLUSION

The observations that As(2)O(3) has a negative impact on the cell cycle checkpoint activation by taxol should have significant clinical implications because the efficacy of taxol in the clinics is associated with its ability to induce mitotic arrest and subsequent mitotic catastrophe.

Computer simulation comparison of tripolar, bipolar, and spline Laplacian electrocadiogram estimators

A comparison of the performance of the tripolar and bipolar concentric as well as spline Laplacian electrocardiograms (LECGs) and body surface Laplacian mappings (BSLMs) for localizing and imaging the cardiac electrical activation has been investigated based on computer simulation. In the simulation a simplified eccentric heart-torso sphere-cylinder homogeneous volume conductor model were developed. Multiple dipoles with different orientations were used to simulate the underlying cardiac electrical activities. Results show that the tripolar concentric ring electrodes produce the most accurate LECG and BSLM estimation among the three estimators with the best performance in spatial resolution.