Background & aim
Due to known limitations of liver biopsy, reliable non-invasive serum biomarkers for chronic liver diseases are needed. We performed serum peptidomics for such investigation in compensated chronic hepatitis B (CHB) patients.
Liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) was used to identify differentially expressed peptides in sera from 40 CHB patients (20 with S0G0-S1G1 and 20 with S3G3-S4G4). Ion pair quantification from differentially expressed peptides in a validation set of sera from 86 CHB patients was done with multiple reaction monitoring (MRM).
21 differentially represented peptide peaks were found through LC-MS/MS. Ion pairs generated from eleven of these peptides (m/z < 800) were quantified by MRM. Summed peak area ratios of 6 ion pairs from peptide m/z 520.3 (176.1, 353.7, 459.8, 503.3, 351.3, 593.1), which was identified as dihydroxyacetone kinase (DAK) fragment, decreased from mild to advanced stages of fibrosis or inflammation. Area Under Receiver Operating Characteristic Curves (AUROCs) of five ion models discriminating fibrosis degrees were 0.871 ~ 0.915 (S2-4 versus S0-1) and 0.804 ~ 0.924 (S3-4 versus S0-2). AUROCs discriminating inflammation grades were 0.840 ~ 0.902 (G2-4 versus G0-1) and 0.787 ~ 0.888 (G3-4 versus G0-2). The diagnostic power of these models provides improved sensitivity and specificity for predicting disease progression as compared to aspartate aminotransferase to platelet ratio index (APRI), FIB-4, Forn’s index and serum DAK protein.
The peptide fragment (m/z 520.3) of DAK is a promising biomarker to guide timing of antiviral treatment and to avoid liver biopsy in compensated CHB patients.
Peptidome; Dihydroxyacetone kinase; Chronic hepatitis B; Multiple reaction monitoring; Liquid chromatography combined with tandem mass spectrometry
Sporadic hepatitis E has become an important public health concern in China. Accurate forecasting of the incidence of hepatitis E is needed to better plan future medical needs. Few mathematical models can be used because hepatitis E morbidity data has both linear and nonlinear patterns. We developed a combined mathematical model using an autoregressive integrated moving average model (ARIMA) and a back propagation neural network (BPNN) to forecast the incidence of hepatitis E.
The morbidity data of hepatitis E in Shanghai from 2000 to 2012 were retrieved from the China Information System for Disease Control and Prevention. The ARIMA-BPNN combined model was trained with 144 months of morbidity data from January 2000 to December 2011, validated with 12 months of data January 2012 to December 2012, and then employed to forecast hepatitis E incidence January 2013 to December 2013 in Shanghai. Residual analysis, Root Mean Square Error (RMSE), normalized Bayesian Information Criterion (BIC), and stationary R square methods were used to compare the goodness-of-fit among ARIMA models. The Bayesian regularization back-propagation algorithm was used to train the network. The mean error rate (MER) was used to assess the validity of the combined model.
A total of 7,489 hepatitis E cases was reported in Shanghai from 2000 to 2012. Goodness-of-fit (stationary R2=0.531, BIC= −4.768, Ljung-Box Q statistics=15.59, P=0.482) and parameter estimates were used to determine the best-fitting model as ARIMA (0,1,1)×(0,1,1)12. Predicted morbidity values in 2012 from best-fitting ARIMA model and actual morbidity data from 2000 to 2011 were used to further construct the combined model. The MER of the ARIMA model and the ARIMA-BPNN combined model were 0.250 and 0.176, respectively. The forecasted incidence of hepatitis E in 2013 was 0.095 to 0.372 per 100,000 population. There was a seasonal variation with a peak during January-March and a nadir during August-October.
Time series analysis suggested a seasonal pattern of hepatitis E morbidity in Shanghai, China. An ARIMA-BPNN combined model was used to fit the linear and nonlinear patterns of time series data, and accurately forecast hepatitis E infections.
Hepatitis E; Combined mathematical model; Forecast
A large number of studies have confirmed that excessive apoptosis is one of the reasons for deficient neuronal function in neural tube defects (NTDs). A previous study from our laboratory used 2-D gel electrophoresis to demonstrate that 14-3-3ζ expression was low in the spinal cords of rat fetuses with spina bifida aperta at embryonic day (E) 17. As a member of the 14-3-3 protein family, 14-3-3ζ plays a crucial role in the determination of cell fate and anti-apoptotic activity. However, neither the expression of 14-3-3ζ in defective spinal cords, nor the correlation between 14-3-3ζ and excessive apoptosis in NTDs has been fully confirmed.
We used immunoblotting and quantitative real-time PCR (qRT-PCR) to quantify the expression of 14-3-3ζ and double immunofluorescence to visualize 14-3-3ζ and apoptosis. We found that, compared with controls, 14-3-3ζ was down-regulated in spina bifida between E12 and E15. Excessive apoptotic cells and low expression of 14-3-3ζ were observed in the dorsal region of spinal cords with spina bifida during the same time period. To initially explore the molecular mechanisms of apoptosis in NTDs, we investigated the expression of microRNA-7 (miR-7), microRNA-375 (miR-375) and microRNA-451 (miR-451), which are known to down-regulate 14-3-3ζ in several different cell types. We also investigated the expression of p53, a molecule that is downstream of 14-3-3ζ and can be down-regulated by it. We discovered that, in contrast to the reduction of 14-3-3ζ expression, the expression of miR-451, miR-375 and p53 increased in spina bifida rat fetuses.
These data suggest that the reduced expression of 14-3-3ζ plays a role in the excessive apoptosis that occurs in spina bifida and may be partly regulated by the over-expression of miR-451 and miR-375, and the consequent up-regulation of p53 might further promote apoptosis in spina bifida.
Equine sarcoids are skin tumours of fibroblastic origin affecting equids worldwide. Bovine papillomavirus type-1 (BPV-1) and, less commonly, type-2 are recognized as etiological factors of sarcoids. The transforming activity of BPV is related to the functions of its major oncoprotein E5 which binds to the platelet-derived growth factor β receptor (PDGFβR) causing its phosphorylation and activation. In this study, we demonstrate, by coimmunoprecipitation and immunoblotting, that in equine sarcoid derived cell lines PDGFβR is phosphorylated and binds downstream molecules related to Ras-mitogen-activated protein kinase-ERK pathway thus resulting in Ras activation. Imatinib mesylate is a tyrosine kinase receptors inhibitor which selectively inhibits the activation of PDGFβR in the treatment of several human and animal cancers. Here we show that imatinib inhibits receptor phosphorylation, and cell viability assays demonstrate that this drug decreases sarcoid fibroblasts viability in a dose-dependent manner. This study contributes to a better understanding of the molecular mechanisms involved in the pathology of sarcoids and paves the way to a new therapeutic approach for the treatment of this common equine skin neoplasm.
This paper describes the first case of infection with a recently described novel bunyavirus, severe fever with thrombocytopenia syndrome virus (SFTSV), in Shanghai, China. The case is originally from Chizhou City, Anhui province within an endemic area for SFTSV. We describe the etiology, epidemiological characteristics, clinical diagnosis and treatment of this fatal case. This case is unique because major cause of death was renal failure, whereas other reported cases have been due to hemorrhage. The investigation and response to this case provides meaningful insight for the early and rapid diagnosis, treatment, prevention and control of severe fever with thrombocytopenia syndrome virus in non-endemic regions in China and globally.
Severe fever and thrombocytopenia syndrome; Bunyavirus; Genetic analysis
There are few articles in the literature comparing outcomes between anterior and posterior instrumentation in the management of thoracic and lumbar spinal tuberculosis (TB).
Between January 2004 and December 2009, 217 adult patients, average age 39 (range 16–67) years with thoracic and lumbar spinal TB were treated by anterior radical debridement and fusion plus instrumentation, anterior radical debridement with fusion and posterior fusion with instrumentation, posterolateral debridement and fusion plus posterior instrumentation or transpedicular debridement and posterior fusion with instrumentation in a single- or two-stage procedure. We followed up 165 patients for 22–72 (mean 37) months. Of these, 138 underwent more than three weeks chemotherapy with isoniazid, rifampin, pyrazinamide and ethambutol, and the remaining 27 underwent operation for neurological impairment within six to 18 hours of the same chemotherapy regimen. In no case did relapse occur. Apart from eight patients with skip lesions treated by hybrid anterior and posterior instrumentation, anterior instrumentation was used in 74 patients (group A) and 83 patients (group B) were fixed posteriorly.
In both groups, local symptoms were relieved significantly one to three weeks postoperatively; ten of 14 patients (71%) in group A and 14 of 19 (74%) in group B with neurological deficit had excellent or good clinical results (P > 0.05). Erythrocyte sedimentation rates (ESR) returned from 43.6 mm/h and 42.7 mm/h, respectively, preoperatively to normal levels eight to 12 weeks postoperatively. Kyphosis degree was corrected by a mean of 11.5° in group A and 12.6° in group B, respectively (P < 0.01). Correction loss was 6.8° in group A and 6.1° in group B at the last follow-up (P < 0.01). Fusion rates of the grafting bone were 92.5% and 91.8%, respectively, at final follow-up (P > 0.05). Severe complications did not occur.
These results suggest that both anterior and posterior instrumentation attain good results for correction of the deformity and maintaining correction, foci clearance, spinal-cord decompression and pain relief in the treatment of thoracic and lumbar spinal TB providing that the opeartive indication is accurately identified. However, the posterior approach may be superior to anterior instrumentation to correct deformity and maintain that correction.
Background: Anorectal malformations (ARMs) represent a variety of congenital disorders that involve abnormal termination of the anorectum. This study was to reveal relation between CDX1 and human ARMs phenotypes.
Methods: 108 Chinese patients and 120 Chinese controls were included in this study. We analyzed the relation between two by PCR, qRT-PCR, western blot and immunofluorescence.
Results: Four heterozygous mutations in CDX1 gene were identified in ARMs patients (3.7%, 4/108), no found in controls. CDX1 protein expression was significantly decreased in the ARMs compared with the control anorectum. All samples analyzed in ARMs group exhibited down-regulated CDX1 mRNA expression in comparison to matched normal group, demonstrated significant differences statistically.
Conclusion: The findings represented the relation between CDX1 mutations and CDX1 genotype. Furthermore, it was suggested that the downregulation of CDX1 might be related to the development of ARMs.
Anorectal malformations; CDX1; mutation; children
The increase in urban migrants is one of major challenges for tuberculosis control in China. The different characteristics of tuberculosis cases between urban migrants and local residents in China have not been investigated before.
We performed a retrospective study of all pulmonary tuberculosis patients reported in Songjiang district, Shanghai, to determine the demographic, clinical and microbiological characteristics of tuberculosis cases between urban migrants and local residents. We calculated the odds ratios (OR) and performed multivariate logistic regression to identify the characteristics that were independently associated with tuberculosis among urban migrants. A total of 1,348 pulmonary tuberculosis cases were reported during 2006–2008, among whom 440 (32.6%) were local residents and 908 (67.4%) were urban migrants. Urban migrant (38.9/100,000 population) had higher tuberculosis rates than local residents (27.8/100,000 population), and the rates among persons younger than age 35 years were 3 times higher among urban migrants than among local residents. Younger age (adjusted OR per additional year at risk = 0.92, 95% CI: 0.91–0.94, p<0.001), poor treatment outcome (adjusted OR = 4.12, 95% CI: 2.65–5.72, p<0.001), and lower frequency of any comorbidity at diagnosis (adjusted OR = 0.20, 95% CI: 0.13–0.26, p = 0.013) were significantly associated with tuberculosis patients among urban migrants. There were poor treatment outcomes among urban migrants, mainly from transfers to another jurisdiction (19.3% of all tuberculosis patients among urban migrants).
A considerable proportion of tuberculosis cases in Songjiang district, China, during 2006–2008 occurred among urban migrants. Our findings highlight the need to develop and implement specific tuberculosis control strategies for urban migrants, such as more exhaustive case finding, improved case management and follow-up, and use of directly observed therapy (DOT).
The aim of this study was to evaluate the efficacy of multi-detector row helical computed tomography (MDCT) angiography in the detection of feeding arteries prior to multi-arterial infusion for lung cancer. A total of 59 consecutive patients (44 males and 15 females; age range, 27–86 years; median age, 62 years) with non-small cell lung cancer underwent MDCT angiography of the thorax prior to multi-arterial infusion for lung cancer. Findings on CT angiograms, including CT scans, maximum intensity projections and three-dimensional volume-rendered images, were used to evaluate the depiction of bronchial and non-bronchial systemic arteries. The results of detecting the feeding arteries for lung cancer by MDCT angiography and conventional angiography were compared. Among the 59 patients treated with multi-arterial infusion chemotherapy, a total of 80 feeding arteries (62 bronchial feeding arteries and 18 non-bronchial systemic arteries) were detected by conventional angiography and/or MDCT angiography. In 56 (70%) feeding arteries (including 44 bronchial feeding arteries and 12 non-bronchial systemic arteries) for lung cancers, concordant findings were observed with the two modalities. In 23 (29%) cases, MDCT angiography could not be used to define feeding arteries, but was used to identify the ostia of these feeding arteries. In one (1/80, 1.3%) case, the CT-defined feeding artery was not selectively catheterized. MDCT angiography of the chest is able to provide an overview for successful catheterization in multi-arterial infusion chemotherapy for lung cancer.
lung cancer; arterial infusion chemotherapy; angiography; feeding artery; computed tomography
Hepatoblastoma (HB) is the most common primary, malignant pediatric liver tumor in children. The treatment results for affected children have markedly improved in recent decades. However, the prognosis for high-risk patients who have extrahepatic extensions, invasion of the large hepatic veins, distant metastases and very high alpha-fetoprotein (AFP) serum levels remains poor. There is an urgent need for the development of novel therapeutic approaches.
An attenuated strain of measles virus, derived from the Edmonston vaccine lineage, was genetically engineered to produce carcinoembryonic antigen (CEA). We investigated the antitumor potential of this novel viral agent against human HB both in vitro and in vivo.
Infection of the Hep2G and HUH6 HB cell lines, at multiplicities of infection (MOIs) ranging from 0.01 to 1, resulted in a significant cytopathic effect consisting of extensive syncytia formation and massive cell death at 72–96 h after infection. Both of the HB lines overexpressed the measles virus receptor CD46 and supported robust viral replication, which correlated with CEA production. The efficacy of this approach in vivo was examined in murine Hep2G xenograft models. Flow cytometry assays indicated an apoptotic mechanism of cell death. Intratumoral administration of MV-CEA resulted in statistically significant delay of tumor growth and prolongation of survival.
The engineered measles virus Edmonston strain MV-CEA has potent therapeutic efficacy against HB cell lines and xenografts. Trackable measles virus derivatives merit further exploration in HB treatment.
Hepatoblastoma; Oncolytic; Measles virus Edmonston strain; CD46
At present, there is no standardized method for the diagnosis and management of pulmonary nodular lesions (PNLs) smaller than 3 cm. This study investigated the use of computed tomography (CT)-guided hookwire localization and video-assisted thoracoscopic surgery (VATS) for PNLs. A total of 103 patients undergoing CT-guided hook-wire localization and VATS were enrolled, and 107 lesions were collected. We assessed the localization achievement ratio, complications rate, conversion thoracotomy rate, intraoperative dislodgement rate, pathological diagnosis rate, duration of surgery and average days of hospitalization. All 107 nodules from 103 patients were successfully localized (100%), the asymptomatic pneumothorax rate was 36.9%, the asymptomatic hemorrhage rate was 40.8% and the simultaneous pneumothorax and hemorrhage rate was 8.7%. A conversion thoracotomy was required in 2 (1.9%) patients and the intraoperative dislodgement rate was 2.9%. The average time for localization was 11±4 min, and the average times for wedge resection and lobectomies were 16±2 and 95±30 min, respectively. The mean hospitalization time following the surgery was 6±3 days. All 107 nodules managed to achieve pathological diagnoses. A combination of CT-guided hook-wire localization and VATS for PNL is a safe and efficient procedure of great clinical value.
pulmonary nodular lesions; ground-glass nodules; hookwire system; video-assisted thoracoscopic surgery
AIM: To investigate whether DNA-dependent activator of interferon-regulatory factors (DAI) inhibits hepatitis B virus (HBV) replication and what the mechanism is.
METHODS: After the human hepatoma cell line Huh7 was cotransfected with DAI and HBV expressing plasmid, viral protein (HBV surface antigen and HBV e antigen) secretion was detected by enzyme-linked immunosorbent assay, and HBV RNA was analyzed by real-time polymerase chain reaction and Northern blotting, and viral DNA replicative intermediates were examined by Southern blotting. Interferon regulatory factor 3 (IRF3) phosphorylation and nuclear translocation were analyzed via Western blotting and immunofluorescence staining respectively. Nuclear factor-κB (NF-κB) activity induced by DAI was detected by immunofluorescence staining of P65 and dual luciferase reporter assay. Transwell co-culture experiment was performed in order to investigate whether the antiviral effects of DAI were dependent on the secreted cytokines.
RESULTS: Viral protein secretion was significantly reduced by 57% (P < 0.05), and the level of total HBV RNA was reduced by 67% (P < 0.05). The viral core particle-associated DNA was also dramatically down-regulated in DAI-expressing Huh7 cells. Analysis of involved signaling pathways revealed that activation of NF-κB signaling was essential for DAI to elicit antiviral response in Huh7 cells. When the NF-κB signaling pathway was blocked by a NF-κB signaling suppressor (IκBα-SR), the anti-HBV activity of DAI was remarkably abrogated. The inhibitory effect of DAI was independent of IRF3 signaling and secreted cytokines.
CONCLUSION: This study demonstrates that DAI can inhibit HBV replication and the inhibitory effect is associated with activation of NF-κB but independent of IRF3 and secreted cytokines.
DNA-dependent activator of interferon regulatory factor; Antiviral activity; Hepatitis B virus; Nuclear factor-κB; Interferon regulatory factor-3
In the title compound, [Pb2(C7H4O6S)2(C12H8N2)2(H2O)2]·CH3COOH, the seven-coordinate PbII atom is chelated by two N atoms of one 1,10-phenanthroline ligand, four O atoms from three 5-sulfosalicylate dianions and one water O atom. Each dianion serves as a bridging ligand, connecting adjacent PbII atoms into a centrosymmetric polymeric chain extending parallel to . There are π–π interactions between the aromatic systems of neighbouring dianions, with plane-to-plane distances of 3.371 (2) Å, and between phenanthroline ligands, with a centroid-to-centroid distance of 3.484 (2) Å. O—H⋯O hydrogen bonding additionally stabilizes the crystal packing. The acetic acid molecules are incorporated in the voids of this arrangement. They exhibit half-occupancy due to disorder around a centre of inversion.
Notch signaling controls multiple developmental processes, thus demanding versatile functions. We have previously shown that this may be partly achieved by accelerating ubiquitin-mediated degradation of important regulators of differentiation. However, the underlying mechanism was unknown. We now find that Notch signaling transcriptionally activates the gene encoding ankyrin-repeat SOCS box-containing protein 2 (Asb2). Asb2 promotes the ubiquitination of Notch targets such as E2A and Janus kinase (Jak) 2, and a dominant-negative (DN) mutant of Asb2 blocks Notch-induced degradation of these proteins. Asb2 likely binds Jak2 directly but associates with E2A through Skp2. We next provide evidence to suggest that Asb2 bridges the formation of non-canonical cullin-based complexes through interaction with not only ElonginB/C and Cullin (Cul) 5, but also the F-box-containing protein, Skp2, which is known to associate with Skp1 and Cul1. Consistently, ablating the function of Cul1 or Cul5 using DN mutants or siRNAs protected both E2A and Jak2 from Asb2-mediated or Notch-induced degradation. By shifting monomeric E3 ligase complexes to dimeric forms through activation of Asb2 transcription, Notch could effectively control the turnover of a variety of substrates and it exerts diverse effects on cell proliferation and differentiation.
Notch; Asb2; ubiquitin; Jak2; Skp2
Targeted delivery is a highly desirable strategy for diagnostic imaging due to enhanced efficacy and reduced dosage/toxicity. The need to develop target-specific magnetic resonance imaging (MRI) contrast agents to aid in disease characterization is highly essential. In this study, a specific contrast agent, Gd-DTPA-poly-L-lysine (PL-Gd-DTPA)-folate, was synthesized and evaluated for its efficacy as a targeted agent for the imaging of tumors that overexpress the folate receptor. Folic acid was conjugated to PL-Gd-DTPA via the ε-amino groups. The receptor binding properties of folate-PL-Gd-DTPA were studied in cultured tumor cells that overexpressed the folate receptor. The tumor-selecting properties of folate-PL-Gd-DTPA were then evaluated in BALB/c mice bearing subcutaneously implanted folate receptor-positive tumors. Tissue MR signal intensities were measured at six different time-points. In the in vitro study, the folate-PL-Gd-DTPA was able to bind to these cells, which overexpressed the folate receptor, as with free folic acid. Excellent tumor selectivity was also shown in the animal model; after the success of injection of folate-PL-Gd-DTPA, a maximum intensity increase of 125.4% was observed from pre-injection compared to post-injection images of the tumor at the 48 h time-point. The liver enhancement was non-specific and the muscle signal intensity at any time-point after injection showed no statistical difference with that observed before injection. Folate-PL-Gd-DTPA is a promising, novel receptor-specific MRI contrast agent with potential applications in the imaging of human folate receptor-positive tumors.
folate receptor; pulmonary tumor; targeted contrast agents; magnetic resonance imaging; gadolinium-DTPA
For high-resolution tandem mass spectra, the determination of monoisotopic masses of fragment ions plays a key role in the subsequent peptide and protein identification. In this paper, we present a new algorithm for deisotoping the bottom-up spectra. Isotopic-cluster graphs are constructed to describe the relationship between all possible isotopic clusters. Based on the relationship in isotopic-cluster graphs, each possible isotopic cluster is assessed with a score function, which is built by combining nonintensity and intensity features of fragment ions. The non-intensity features are used to prevent fragment ions with low intensity from being removed. Dynamic programming is adopted to find the highest score path with the most reliable isotopic clusters. The experimental results have shown that the average Mascot scores and F-scores of identified peptides from spectra processed by our deisotoping method are greater than those by YADA and MS-Deconv software.
The purpose of this study was to determine whether computed tomographic scans and attenuation measurements on contrast material-enhanced and non-enhanced computed tomographic scans could be used to characterize solitary pulmonary nodules and, in particular, to characterize these lesions using washout characteristics on contrast-enhanced computed tomography. A total of 63 patients (38 males, 25 females; age range, 21–80 years; mean age, 58±13.2 years) with pulmonary nodules revealed on contrast-enhanced computed tomography underwent 20-min delayed enhanced scans. The mean diameter of the pulmonary nodules was 1.8±0.6 cm (range, 0.8–2.9). Region-of-interest measurements were obtained at non-enhanced, dynamic enhanced and delayed enhanced computed tomography and were used to calculate a relative percentage washout as follows: 1 - (Hounsfield unit measurement on delayed image/Hounsfield unit measurement on dynamic image) × 100%. There was a mean relative washout of 33% on the delayed computed tomographic scans (range, 12–46) in benign solitary pulmonary nodules; and a mean relative washout of 7% (range, −36–51) in malignant solitary pulmonary nodules (Mann-Whitney U test, p<0.001). Results of the receiver operating curve analysis revealed that a threshold relative washout of 14.5% had 74.3% sensitivity and 92.9% specificity for identifying malignant nodules. Calculation of the relative percentage washout on dynamic and delayed enhanced computed tomographic scans may lead to a highly specific test for solitary pulmonary nodule characterization and reduce the need for, and possibly obviate, follow-up imaging or biopsy.
pulmonary nodules; lung cancer; computed tomography; washout
Rare (RVs) and common variants of the RET gene contribute to Hirschsprung disease (HSCR; congenital aganglionosis). While RET common variants are strongly associated with the commonest manifestation of the disease (males; short-segment aganglionosis; sporadic), rare coding sequence (CDS) variants are more frequently found in the lesser common and more severe forms of the disease (females; long/total colonic aganglionosis; familial).
Here we present the screening for RVs in the RET CDS and intron/exon boundaries of 601 Chinese HSCR patients, the largest number of patients ever reported. We identified 61 different heterozygous RVs (50 novel) distributed among 100 patients (16.64%). Those include 14 silent, 29 missense, 5 nonsense, 4 frame-shifts, and one in-frame amino-acid deletion in the CDS, two splice-site deletions, 4 nucleotide substitutions and a 22-bp deletion in the intron/exon boundaries and 1 single-nucleotide substitution in the 5′ untranslated region. Exonic variants were mainly clustered in RET the extracellular domain. RET RVs were more frequent among patients with the most severe phenotype (24% vs. 15% in short-HSCR). Phasing RVs with the RET HSCR-associated haplotype suggests that RVs do not underlie the undisputable association of RET common variants with HSCR. None of the variants were found in 250 Chinese controls.
Notch signaling controls multiple developmental processes, thus demanding versatile functions. We have previously shown that this may be partly achieved by accelerating ubiquitin-mediated degradation of important regulators of differentiation. However, the underlying mechanism was unknown. We now find that Notch signaling transcriptionally activates the gene encoding ankyrin-repeat and SOCS box-containing protein 2 (Asb2). Asb2 promotes the ubiquitination of Notch targets such as E2A and Jak2, and a dominant-negative mutant of Asb2 blocks Notch-induced degradation of these proteins. Asb2 likely binds Jak2 directly but associates with E2A through Skp2. We next provide evidence to suggest that Asb2 bridges the formation of non-canonical cullin-based complexes through interaction with not only ElonginB/C and Cul5 but also with the F-box containing protein, Skp2, which is known to associate with Skp1 and Cul1. Consistently, ablating the function of Cul1 or Cul5 using dominant negative mutants or siRNAs protected both E2A and Jak2 from Asb2 or Notch-induced degradation. By shifting monomeric E3 ligase complexes to dimeric forms through activation of Asb2 transcription, Notch could effectively controls the turnover of a variety of substrates and exerts diverse effects on cell proliferation and differentiation.
Notch; Asb2; ubiquitin; Jak2; Skp2
The transcription regulator CITED2 (CBP/p300-Interacting-Transactivator-with-ED-rich-tail-2) is known to suppress genes mediating angiogenesis and extracellular matrix (ECM) remodeling. However, it is unclear whether CITED2 has a role in controlling skeletal repair or remodeling. We tested the hypothesis that CITED2 functions in bone fracture healing by suppressing the expression of genes critical to ECM remodeling, angiogenesis and osteogenesis, importantly the matrix metalloproteinases (MMPs). Three hours following mandibular osteotomy or sham surgery of adult rats, osteotomy fronts were harvested and the expression of CITED2 and genes associated with fracture healing was quantitated by quantitative PCR. In parallel, gain-of-function studies examined the effect of overexpressing CITED2 on the expression and activity of several MMPs. In the fractured mandible, CITED2 expression was inversely related to the expression of MMP-2, -3, -9, -13, VEGF, HIF-1α, M-CSF, RANK-L, and OPG. Consistent with this, the over-expression of CITED2 in osteoblasts inhibited the expression and activity of MMP-2, -3, -9 and -13. Taken together, the studies suggest that CITED2 is a critical upstream regulator of fracture healing. The suppression of CITED2 early after fracture may allow an optimal initiation of the healing response.
CITED2; bone fracture healing; ECM remodeling; angiogenesis; osteogenesis; matrix metalloproteinases
AIM: To evaluate the suitability of rupintrivir against Enterovirus 71 (EV71) induced severe clinical symptoms using computational methods.
METHODS: The structure of EV71 3C protease was predicted by homology modeling. The binding free energies between rupintrivir and EV71 3C and human rhinovirus 3C protease were computed by molecular dynamics and molecular mechanics Poisson-Boltzmann/surface area and molecular mechanics generalized-born/surface area methods. EV71 3C fragments obtained from clinical samples collected during May to July 2008 in Shanghai were amplified by reverse-transcription and polymerase chain reaction and sequenced.
RESULTS: We observed that rupintrivir had favorable binding affinity with EV71 3C protease (-10.76 kcal/mol). The variability of the 3C protein sequence in isolates of various outbreaks, including those obtained in our hospital from May to July 2008, were also analyzed to validate the conservation of the drug binding pocket.
CONCLUSION: Rupintrivir, whose safety profiles had been proved, is an attractive candidate and can be quickly utilized for treating severe EV71 infection.
Rupintrivir; Hand foot and mouth disease; Molecular mechanics Poisson-Boltzmann/surface area; Molecular mechanics Generalized-Born/surface area; Homology modeling; Picornavirus
RNA-protein interactions are important for a wide range of biological processes. Current computational methods to predict interacting residues in RNA-protein interfaces predominately rely on sequence data. It is, however, known that interface residue propensity is closely correlated with structural properties. In this paper we systematically study information obtained from sequences and structures and compare their contributions in this prediction problem. Particularly, different geometrical and network topological properties of protein structures are evaluated to improve interface residue prediction accuracy.
We have quantified the impact of structural information on the prediction accuracy in comparison to the purely sequence based approach using two machine learning techniques: Naïve Bayes classifiers and Support Vector Machines. The highest AUC of 0.83 was achieved by a Support Vector Machine, exploiting PSI-BLAST profile, accessible surface area, betweenness-centrality and retention coefficient as input features. Taking into account that our results are based on a larger non-redundant data set, the prediction accuracy is considerably higher than reported in previous, comparable studies. A protein-RNA interface predictor (PRIP) and the data set have been made available at .
Graph-theoretic properties of residue contact maps derived from protein structures such as betweenness-centrality can supplement sequence or structure features to improve the prediction accuracy for binding residues in RNA-protein interactions. While Support Vector Machines perform better on this task, Naïve Bayes classifiers also have been found to achieve good prediction accuracies but require much less training time and are an attractive choice for large scale predictions.
Information about the risk factors associated with death caused by tuberculosis (TB) or death with TB would allow improvements in the clinical care of TB patients and save lives. The present study sought to identify characteristics associated with increased risk of death during anti-TB treatment in Shanghai, a city in China with one of the country's highest TB mortality rates.
We evaluated deaths among culture positive pulmonary TB cases that were diagnosed in Shanghai during 2000–2004 and initiated anti-TB therapy. Demographic, clinical, mycobacteriological information and treatment outcomes were routinely collected through a mandatory reporting system.
There were 7,999 culture positive pulmonary cases reported during the study period. The overall case fatality rate was 5.5% (440 cases), and approximately half (50.5%) of the deaths were attributed to causes other than TB. Eighty-six percent of the deaths were among TB cases age ≥ 60 years. The significant independent risk factors for mortality during anti-TB treatment were advancing age, male sex, sputum smear positivity, and the presence of a comorbidity.
More vigorous clinical management and prevention strategies by both the TB control program and other public health programs are essential to improve TB treatment outcomes. Earlier suspicion, diagnosis and treatment of TB, especially among persons older than 60 years of age and those with a comorbid condition, could reduce deaths among TB patients.