The FEN1 E359K germline mutation disrupts the FEN1-WRN interaction and FEN1 GEN activity, causing aneuploidy-associated cancers

Polymorphisms and somatic mutations in Flap Endonuclease 1 (FEN1), an essential enzyme involved in DNA replication and repair, can lead to functional deficiencies of the FEN1 protein and a predisposition to cancer. We identified a FEN1 germline mutation which changed residue E359 to K in a patient whose family had a history of breast cancer. We determined that the E359K mutation, which is in the protein-protein domain of FEN1, abolished the interaction of FEN1 with Werner Syndrome protein (WRN), an interaction which is critical for resolving stalled DNA replication forks. Furthermore, although the flap endonuclease activity of FEN1 E359K was unaffected, it failed to resolve bubble structures, which requires the FEN1 gap dependent endonuclease (GEN) activity. To determine the etiological significance of E359K, we established a mouse model containing this mutation. E359K mouse embryonic fibroblasts (MEF) were more sensitive to DNA cross-linking agents that cause replication forks to stall. Cytological analysis suggested that the FEN1-WRN interaction was also required to for telomere stability; mutant cell lines had fragile telomeres, increased numbers of spontaneous chromosomal anomalies and higher frequencies of transformation. Moreover, the incidence of cancer was significantly higher in mice homozygous for FEN1 E359K than in wild-type mice, suggesting that the FEN1 E359K mutation is oncogenic.

The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org, p. 267]. For low intensity ion beam [30-300 keV/1 pA-10 μA], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 μA], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

An ion source module for the Beijing Radioactive Ion-beam Facility

An ion source module is developed for Beijing Radioactive Ion-beam Facility. The ion source module is designed to meet the requirements of remote handling. The connection and disconnection of the electricity, cooling and vacuum between the module and peripheral units can be executed without on-site manual work. The primary test of the target ion source has been carried out and a Li(+) beam has been extracted. Details of the ion source module and its primary test results are described.

The development of the high intensity electron cyclotron resonance ion source at China Institute of Atomic Energy

High-current microwave ion source has been under development over 15 years for accelerator driven sub-critical system research at China Institute of Atomic Energy, and the beam intensity higher than 140 mA proton beam is produced by this ion source with long lifetime and high reliability. The emittance of high intensity continue-wave and pulse beam is measured on a test-bench in the laboratory. Based on the good performance of this proton ion source, a new 120 mA deuterium ion source is proposed for a high intensity neutron generator. The ion source details and status will be presented.

Prognostic value of 1p deletion for multiple myeloma: a meta-analysis

INTRODUCTION

Previous studies have indicated that a deletion on the short arm of chromosome 1 negatively predicts survival in patients with multiple myeloma (MM). Due to the small sample size in each study, we performed this meta-analysis to comprehensively investigate the association between the 1p deletion and survival in patients with MM.

METHODS

A literature search was conducted in both foreign and Chinese databases, including SinoMed, CNKI, Wanfang, PubMed, EMBASE, and Scopus. Hazard ratios (HR) with 95% confidence intervals (CI) for overall survival (OS) and progression-free survival (PFS) in 11 eligible articles were extracted or calculated to analyze the pooled HR, which was estimated by fixed-effect or random-effect models based on the heterogeneity between included articles. A subgroup analysis and a meta-regression were conducted, and Galbraith plots were generated to examine any possible heterogeneity.

RESULTS

The HRs for OS were available in nine articles, whereas five articles discussed HRs for PFS. The HR with 95%CI was 1.989 (95%CI 1.522-2.600, P = 0.017, I(2)  = 57.1%) when comparing the OS of patients with 1p deletion with the OS of those without this deletion. For PFS, 1p deletion still predicted a poor prognosis (HR 2.11, 95%CI 1.54-2.88, P = 0.292, I(2)  = 19.3%). Moreover, the subgroup analysis suggested that either the deleted gene on 1p or techniques for detecting chromosome abnormalities contributed to the heterogeneity, which was partially consistent with the results derived from a meta-regression analysis and the Galbraith plot method.

CONCLUSION

Our meta-analysis provides globally quantifiable confirmation of the adverse prognostic role of 1p deletion in OS and PFS for patients with MM.

STAT1-mediated Bim expression promotes the apoptosis of retinal pericytes under high glucose conditions

Hyperglycemia impacts different vascular cell functions and promotes the development and progression of various vasculopathies including diabetic retinopathy. Although the increased rate of apoptosis in pericytes (PCs) has been linked to increased oxidative stress and activation of protein kinase C-δ (PKC-δ) and SHP-1 (Src homology region 2 domain-containing phosphatase-1) tyrosine phosphatase during diabetes, the detailed mechanisms require further elucidation. Here we show that the rate of apoptosis and expression of proapoptotic protein Bim were increased in the retinal PCs of diabetic Akita/+ mice and mouse retinal PCs cultured under high glucose conditions. Increased Bim expression in retinal PCs under high glucose conditions required the sustained activation of signal transducer and activator of transcription 1 (STAT1) through production of inflammatory cytokines. PCs cultured under high glucose conditions also exhibited increased oxidative stress and diminished migration. Inhibition of oxidative stress, PKC-δ or Rho-associated protein kinase I/II was sufficient to protect PCs against apoptosis under high glucose conditions. Furthermore, PCs deficient in Bim expression were protected from high glucose-mediated increased oxidative stress and apoptosis. However, only inhibition of PKC-δ lowered Bim levels. N-acetylcysteine did not affect STAT1 levels, suggesting that oxidative stress is downstream of Bim. PCs cultured under high glucose conditions disrupted capillary morphogenesis of retinal endothelial cells (ECs) in coculture experiments. In addition, conditioned medium prepared from PCs under high glucose conditions attenuated EC migration. Taken together, our results indicate that Bim has a pivotal role in the dysfunction of retinal PCs under high glucose conditions by increasing oxidative stress and death of PCs.

Prognostic implication of TIM-3 in clear cell renal cell carcinoma

Clear cell renal carcinoma (ccRCC) is the most common tumor of the kidney.in adults. The prognosis of ccRCC remains unsatisfactory. Recently, T cell immunoglobulin mucin-3 (TIM-3), a novel transmembrane protein, has been implicated in tumor biology. Its role in ccRCC remains unknown. The aim of this study was to investigate the roles of TIM-3 as a prognostic marker in patients with ccRCC.TIM-3 protein expression was determined by immunohistochemistry and Western blot from 137 ccRCC tumor samples and adjacent normal renal tissues. We performed also the cell proliferation assay using 3-(4,5-dimethylthiazol -2yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) and cell invasion assay. The effects of small interfering RNA (siRNA)-mediated knockdown of TIM-3 (TIM-3 siRNA) in two human ccRCC cell lines were evaluated. TIM-3 expression was higher in ccRCC tissue than in the adjacent normal renal tissue (P<0.001). High TIM-3 expression was an independent predictor of both cancer-specific survival and progression-free survival. TIM-3 protein was expressed in both ccRCC cell lines. Knockdown of TIM-3 suppressed the proliferation and invasion capacity of ccRCC cell lines.TIM-3 expression was associated with poor prognosis in ccRCC. Taken together, TIM-3 is a potential prognostic marker in ccRCC.

Hypoxia induces osteogenesis in rabbit adipose-derived stem cells overexpressing bone morphogenic protein-2

OBJECTIVE

Hypoxic culture potentiates mesenchymal stem cells (MSCs) to survive and secrete various growth factors. Genetically modified stem cells overexpressing bone morphogenic protein-2 (BMP-2) demonstrate strong osteogenic ability. Hence, we investigated the coeffect of hypoxic culture conditions and BMP-2 overexpression on the osteogenic ability of rabbit adipose-derived stem cells (rASCs) in vitro.

MATERIALS AND METHODS

Rabbit adipose-derived stem cells with or without adenoviral-BMP-2 transduction were cultured in hypoxic (1%) and normoxic (21%) conditions. Cell viability, attachment, and proliferation were compared. Real-time PCR amplification of osteogenic and angiogenic genes including alkaline phosphatase (ALP), osteocalcin (OCN), HIF-1α, and vascular endothelial growth factor (VEGF) was performed. Moreover, ALP activity, immunofluorescent staining of OCN, and mineralization assay by alizarin red S quantification and von Kossa staining were conducted.

RESULTS

Cells under hypoxic conditions attached better within 12 h and proliferated faster. While BMP-2 overexpression and hypoxic condition separately elevated the transcription of key osteogenic and angiogenic genes, a cooperative effect was observed to enhance the upregulation of osteogenic as well as angiogenic genes. Identical changes were observed in ALP activity, immunofluorescent staining of OCN, and mineralization assay.

CONCLUSIONS

Hypoxic culture can enhance the osteogenic ability of BMP-2 gene-modified rASCs, which provides a strategy to improve the osteogenesis of rASCs for in vivo bone regeneration.

The safety and efficacy of stenting in the treatment of complex posterior cerebral artery aneurysms: a seven-case report and literature review

OBJECTIVE

To investigate the safety and efficacy of stenting with coil in the endovascular treatment of complex posterior cerebral artery (PCA) aneurysms.

METHODS

The data on PCA aneurysms treated with stents were retrospectively reviewed from a prospectively collected intervention database. The literature was reviewed concerning the use of stents for PCA aneurysms.

RESULTS

Seven cases with complex PCA aneurysms (male: female = 6:1; ruptured: unruptured = 4:3) were retrieved from our database. Three aneurysms were localized at the junction of P1 and P2 segments (P1-2), two at P1, and two at P2A. Four were wide-necked saccular aneurysms, while the other three were dissecting ones. A total of nine stents (one Neuroform and eight Enterprise stents) were successfully deployed. Two aneurysms were totally eliminated, three were with neck residues and two were partially occluded. No procedure-related complications occurred. All patients recovered well. Angiographic follow-ups (FU) showed that three aneurysms achieved total obliterations, one got improved, two remained stable, and one recurred. The recurred aneurysm caused no symptom and was treated with two stents. Clinical FU demonstrated no neurological deterioration or bleeding. In literature review, the procedure-related mortality is 5.3 % (2/38). The incidence of permanent neurologic deficit is 2.6 % (1/38). Three (3/23) aneurysms recurred, of which one caused rebleeding. Four (4/23) in-stent stenoses were all asymptomatic. No other hemorrhagic or ischemic event occurred in clinical FU.

CONCLUSION

Stent offers a therapeutic alternative for complex PCA aneurysms especially when PVO cannot be tolerated. Long-term therapeutic efficacy requires further observations in clinical series with larger case numbers.

Analysis of morphologic and hemodynamic parameters for unruptured posterior communicating artery aneurysms with oculomotor nerve palsy

BACKGROUND AND PURPOSE

Posterior communicating artery aneurysms with oculomotor nerve palsy may imply sudden enlargement of the aneurysm sac and have a high risk of rupture. Our aim was to identify the morphologic and hemodynamic parameters in this special period of aneurysm progression and to assess related rupture risk indices.

MATERIALS AND METHODS

We analyzed the morphologic and hemodynamic parameters of 9 unruptured posterior communicating artery aneurysms with oculomotor nerve palsy and 9 ruptured ones. The morphologic parameters were measured and calculated from patient-specific 3D rotational angiographic images, and pulsatile computational fluid dynamic simulation was then performed for hemodynamic parameters.

RESULTS

There was no significant statistical difference between the 2 groups in size, aspect ratio, size ratio, aneurysm angle, or vessel angle; analysis only demonstrated a significantly lower wall shear stress of the aneurysm wall in the symptomatic unruptured group in hemodynamics (P = .024), whereas there were no differences in wall shear stress of the parent artery, low wall shear stress area, and oscillatory shear index.

CONCLUSIONS

From morphologic and hemodynamic perspectives, we demonstrated that posterior communicating artery aneurysms with oculomotor nerve palsy had characteristics similar to those of ruptured ones, except for lower wall shear stress on the aneurysm wall, which might indicate an important role in aneurysm rupture.

Production of a sterilised decellularised tendon allograft for clinical use

Application of a high-level decontamination or sterilisation procedure and cell removal technique to tendon allograft can reduce the concerns of disease transmission, immune reaction, and may improve remodelling of the graft after implantation. The decellularised matrix can also be used as a matrix for tendon tissue engineering. One such sterilisation factor, Peracetic acid (PAA) has the advantage of not producing harmful reaction residues. The aim of this study was to evaluate the effects of PAA treatment and a cell removal procedure on the production of tendon matrix. Human patellar tendons, thawed from frozen were treated respectively as: Group 1, control with no treatment; Group 2, sterilised with PAA (0.1 % (w/v) PAA for 3 h) Group 3, decellularised (incubation successively in hypotonic buffer, 0.1 % (w/v) sodium dodecyl sulphate, and a nuclease solution); Group 4, decellularised and PAA sterilised. Histological analysis showed that no cells were visible after the decellularisation treatment. The integrity of tendon structure was maintained after decellularisation and PAA sterilisation, however, the collagen waveform was slightly loosened. No contact cytotoxicity was found in any of the groups. Determination of de-natured collagen showed no significant increase when compared with the control. This suggested that the decellularisation and sterilisation processing procedures did not compromise the major properties of the tendon. The sterilised, decellularised tendon could be suitable for clinical use.

Triggers of migraine and tension-type headache in China: a clinic-based survey

BACKGROUND AND PURPOSE

Identification of the trigger factors of headache could be an important aspect of preventive management, but the characteristics of primary headache triggers in China are unknown. This study was performed to estimate the frequencies of the putative headache triggers, which are endorsed by patients with migraine and tension-type headache (TTH).

METHODS

From July 2011 to December 2011, a cross-sectional survey was conducted in the neurological clinic of a tertiary care hospital in Chongqing. All consecutive patients with the chief complaint of headache were interviewed by a board-certified headache specialist. The diagnoses were made according to International Classification of Headache Disorders - 2nd edition. Patients with migraine and TTH were recruited.

RESULTS

The number of investigated patients was 1219, of whom 394 were migraine and 344 were TTH; and 80.2% migraineurs and 67.4% TTH patients reported trigger factors. The most common triggers for both migraine and TTH were sleep disturbance, negative affect and sunlight. Menstrual cycle (OR 3.6, 95%CI 1.2, 11.2), change of the weather (OR 3.1, 95%CI 1.9, 4.8), noise (OR 2.2, 95%CI 1.1, 4.4) and alcohol (OR 1.8, 95%CI 0.7, 1.8) were more associated with migraineurs. Negative affect was more associated with TTH (OR 2.0, 95%CI 1.3, 2.9).

CONCLUSIONS

Trigger factors were frequent among both migraine and TTH patients. Avoidance of all headache triggers is impractical. Learning to cope with triggers is important to headache prevention.

Prediction of digestible and metabolizable energy content and standardized ileal amino Acid digestibility in wheat shorts and red dog for growing pigs

Two experiments were conducted to evaluate the effects of chemical composition of wheat shorts and red dog on energy and amino acid digestibility in growing pigs and to establish prediction models to estimate their digestible (DE) and metabolizable (ME) energy content and as well as their standardized ileal digestible (SID) amino acid content. For Exp. 1, sixteen diets were fed to thirty-two growing pigs according to a completely randomized design during three successive periods. The basal diet was based on corn and soybean meal while the other fifteen diets contained 28.8% wheat shorts (N = 7) or red dog (N = 8), added at the expense of corn and soybean meal. Over the three periods, each diet was fed to six pigs with each diet being fed to two pigs during each period. The apparent total tract digestibility (ATTD) of energy in wheat shorts and red dog averaged 75.1 and 87.9%. The DE values of wheat shorts and red dog averaged 13.8 MJ/kg (range 13.1 to 15.0 MJ/kg) and 15.1 MJ/kg (range 13.3 to 16.6 MJ/kg) of dry matter, respectively. For Exp. 2, twelve growing pigs were allotted to two 6×6 Latin Square Designs with six periods. Ten of the diets were formulated based on 60% wheat shorts or red dog and the remaining two diets were nitrogen-free diets based on cornstarch and sucrose. Chromic oxide (0.3%) was used as an indigestible marker in all diets. There were no differences (p>0.05) in SID values for the amino acids in wheat shorts and red dog except for lysine and methionine. Apparent ileal digestibility (AID) and SID values for lysine in different sources of wheat shorts or red dog, which averaged 78.1 and 87.8%, showed more variation than either methionine or tryptophan. A stepwise regression was performed to establish DE, ME and amino acid digestibility prediction models. Data indicated that fiber content and amino acid concentrations were good indicators to predict energy values and amino acid digestibility, respectively. The present study confirms the large variation in the energy content and amino acid digestibility in wheat shorts and red dog, and describes the factors that influence this variation and presents equations based on chemical composition that could probably be used to predict the DE and ME values as well as the amino acid digestibility of wheat shorts and red dog.

Localization of peroxisome proliferator-activated receptor in mouse and rat-tissues and demonstration of its nuclear translocation in transfected cv-1 cells

Hepatocarcinogenesis in rodents induced by nongenotoxic peroxisome proliferators is postulated to be a receptor-mediated process. The peroxisome proliferator-activated receptors (PPAR) are members of the steroid hormone receptor superfamily, which participate in ligand-dependent transcriptional activation of peroxisomal fatty acid beta oxidation enzyme system genes in liver parenchymal cells of rats and mice. In order to study the tissue distribution and cellular localization of PPAR, we raised polyclonal antibodies against PPAR using a recombinant rat PPAR (rPPAR) expressed as a glutathione-S-transferase-rPPAR fusion protein. On immunoblot analysis the antibodies specifically recognized a 55 kDa PPAR protein in rat, mouse and human liver homogenates. Immunoblotting also showed that in the mouse and rat, PPAR is expressed in liver, kidney and heart, and only weakly in brain and testis. Immunohistochemical localization in the rat and mouse revealed that PPAR is highly expressed in perivenular (i.e., those surrounding hepatic vein) hepatocytes and very weakly in the cytoplasm of remaining hepatocytes. In the kidney, PPAR was visualized predominantly in the p(3) segments of proximal convoluted tubular epithelium. CV-1 cells transiently transfected with rPPAR cDNA construct showed predominant cytoplasmic fluorescence; treatment of these cells with ciprofibrate, a peroxisome proliferator, resulted in the nuclear translocation of PPAR signal.

RIP140 is associated with subclinical inflammation in type 2 diabetic patients

AIMS

To evaluate the expression level of RIP140 (receptor interaction protein 140) and its correlation with inflammatory cytokine production and free fatty acids (FFAs) in type 2 diabetes.

METHODS

Plasma and peripheral blood mononuclear cells (PBMCs) were collected from 24 diabetic and 30 healthy individuals. The levels of FFAs, TC, TG, HDL-C, LDL-C, FIN, and FBG were measured. The insulin resistance index was calculated using the homeostasis model assessment (HOMA). Additionally, PBMCs from control group were cultured alone or with 500 μmol/L palmitic acid (PA). Levels of RIP140 TNF-α, and IL-6 in PBMCs were analyzed using real-time RT-PCR, Western blots and ELISA. The relationship between RIP140 and other variables was performed using SPSS 11.5 software.

RESULTS

TG, LDL-C, FIN, FBG, HOMA, and HDL-C were significantly different between diabetic patients and the control group. Levels of RIP140, TNF-α, and IL-6 were higher in the diabetic group compared to control. RIP140 expression was positively correlated with FFAs, HDL-c, TNF-α, IL-6, FIN, FBG, and HOMA. Finally, 500 μmol/L PA treatment increased RIP140 expression and the secretion of inflammatory cytokines in cultured control PBMCs.

CONCLUSIONS

Increased RIP140 level may be closely associated with inflammation and disorder of lipid and glucose metabolism in diabetic patients.

Use of onyx for transarterial balloon-assisted embolization of traumatic carotid cavernous fistulas: a report of 23 cases

BACKGROUND AND PURPOSE

TCCFs are a common complication following craniofacial trauma and are usually treated by coils or detachable balloons. The use of the liquid embolic agent Onyx as the sole agent for the treatment of TCCFs has been rarely reported. Herein, we summarized the preliminary experience and effectiveness of treating TCCFs with Onyx in 23 patients.

MATERIALS AND METHODS

From the 36 type A CCFs treated in our department between September 2005 and March 2011, a total of 23 posttraumatic direct CCFs were treated by using Onyx only via transarterial approach.

RESULTS

Immediate postprocedural angiograms demonstrated complete occlusion in all patients. All the patients underwent a single procedure except 1 with bilateral TCCFs. Up to 24-month clinical and 3-month angiographic follow-ups revealed an ongoing complete occlusion without any complications.

CONCLUSIONS

In this series, the use of Onyx for the transarterial embolization of TCCFs was feasible and effective. Associated adverse events were rare.

Protein transduction domain-hA20 fusion protein protects endothelial cells against high glucose-induced injury

We constructed a plasmid containing a protein transduction domain (PTD) and a human A20 (hA20) gene fragment; the fusion protein was obtained by highly expressing this plasmid in the yeast Pichia pastoris GS115. The plasmid was obtained by adding 9xArg and EcoRІ recognition sites to the end of the primer, and 6xHis-Tag and NotІ recognition sites to its end. After sequencing, the hA20 gene fragment was inserted into plasmid pPIC9k to construct expression vector pPIC9k-PTD-hA20; then, we transfected GS115 with the vector and induced PTD-hA20 protein expression. We purified protein from the yeast fermentation supernatant using a nickel column. Human umbilical vein endothelial cells (HUVECs) were cultured in high glucose medium (30 mM glucose) and in high glucose medium containing different concentrations of protein. Apoptosis of HUVECs was assayed by TUNEL 72 h later. The biological activity tests indicated that the fusion protein not only passed through the cell membrane freely, but also inhibited apoptosis of HUVECs induced by high glucose levels. We conclude that the fusion protein PTD-hA20 has potential for clinical use.