Epidemiological characteristics of motor neuron disease in Chinese patients

BACKGROUND

The epidemiology, diagnosis, and treatment of motor neuron disease (MND) in Chinese patients are ill known.

METHODS

A registered study of 461 MND patients was conducted across 10 facilities in 7 Chinese cities from February 2009 to March 2010.

RESULTS

Patients were classified as amyotrophic lateral sclerosis (ALS) (84.4%), progressive bulbar palsy (PBP) (4.1%), progressive muscular atrophy (PMA) (10.4%), or primary lateral sclerosis (PLS) (0.9%). MND was predominant in men (men/women; 1.6:1.0). Mean onset age was 52.6 years, with the highest incidence being observed between 51 and 60 years. Notably, 26.0% of MND patients were employed in forestry, fishery, or animal husbandry industries. Ten cases (2.7%) reported family history of MND, and 54.2% exhibited cervical onset. MND was also associated with head/neck trauma. Non-invasive positive pressure ventilation was the most common supportive therapy.

CONCLUSION

As a novel comprehensive report of a Chinese population, this study reveals that epidemiological characteristics of MND patients were similar to those observed in international populations. MND is age-related, male gender predominant, and may be associated with both environmental and genetic risk factors.

Note: Dynamic strain field mapping with synchrotron X-ray digital image correlation

We present a dynamic strain field mapping method based on synchrotron X-ray digital image correlation (XDIC). Synchrotron X-ray sources are advantageous for imaging with exceptional spatial and temporal resolutions, and X-ray speckles can be produced either from surface roughness or internal inhomogeneities. Combining speckled X-ray imaging with DIC allows one to map strain fields with high resolutions. Based on experiments on void growth in Al and deformation of a granular material during Kolsky bar/gas gun loading at the Advanced Photon Source beamline 32ID, we demonstrate the feasibility of dynamic XDIC. XDIC is particularly useful for dynamic, in-volume, measurements on opaque materials under high strain-rate, large, deformation.

Randomised clinical trial: L-ornithine-L-aspartate reduces significantly the increase of venous ammonia concentration after TIPSS

BACKGROUND

Use of TIPSS is associated with increases in ammonia concentration and hepatic encephalopathy (HE) risk. L-ornithine-L-aspartate (LOLA) is effective in reducing ammonia concentration.

AIM

To evaluate the effects of LOLA on venous ammonia concentration after TIPSS.

METHODS

The included patients were randomised to receive LOLA or no-LOLA treatment for 7 days. Fasting and post-prandial venous ammonia levels were the primary outcomes. Psychometric performance, post-TIPSS HE, and liver and renal function were assessed as secondary outcomes.

RESULTS

Of 133 cirrhotic patients who received successful TIPSS between November 2011 and June 2012, 40 met the inclusion criteria and were randomised to the LOLA (n = 21) or control (n = 19) groups. Change in fasting ammonia significantly favoured the LOLA group at days 4 (P = 0.001) and 7 (P = 0.003). Changes in post-prandial ammonia concentration significantly favoured the LOLA group at days 1, 4 and 7 as well. During the study period, patients in the LOLA group had better improvement in psychometric tests than those in the control group. Overt HE during treatment was observed in one patient in the LOLA group and three patients in the control group (P = 0.331). There were no differences in complications, adverse events or mortality between the two groups.

CONCLUSIONS

Prophylactic use of LOLA infusion after TIPSS is safe and effective in significantly reducing the increase of venous ammonia concentration, and can benefit the patient's mental status as well.

Raman scattering reveals strong LO-phonon-hole-plasmon coupling in nominally undoped GaAsBi: optical determination of carrier concentration

We report room-temperature Raman scattering studies of nominally undoped (100) GaAs1−xBix epitaxial layers exhibiting Bi-induced (p-type) longitudinal-optical-plasmon-coupled (LOPC) modes for 0.018 ≤ x ≤ 0.048. Redshifts in the GaAs-like optical modes due to alloying are evaluated and are paralleled by strong damping of the LOPC. The relative integrated Raman intensities of LO(Γ) and LOPC ALO/ALOPC are characteristic of heavily doped p-GaAs, with a remarkable near total screening of the LO(Γ) phonon (ALO/ALOPC → 0) for larger Bi concentrations. A method of spectral analysis is set out which yields estimates of hole concentrations in excess of 5×1017cm−3 and correlates with the Bi molar fraction. These findings are in general agreement with recent electrical transport measurements performed on the alloy, and while the absolute size of the hole concentrations differ, likely origins for the discrepancy are discussed. We conclude that the damped LO-phonon-hole-plasmon coupling phenomena plays a dominant role in Raman scattering from unpassivated nominally undoped GaAsBi.

Retrospective analysis of factors affecting the efficacy of surgical treatment of the scar

AIM

The scar is a major problem in the medical profession. Its timely treatment is very important for the better outcome of the scar treatment and for the improvement of the life quality of the patients. The aim of this study was retrospectively analyzed the epidemiological characteristics affecting the efficacy of the scar surgical treatment of the people in the western part of China.

METHODS

Total 414 scar cases were retrospectively analyzed to clarify the epidemiological characteristics and the factors affecting the scar surgical treatment efficacy. The factors included were sex, age, area distribution, treatment seasons, injury sites, injury causes, and the time from scarring to the surgical treatment. All scar cases were surgically treated with the repairing technology including skin graft, flap and soft tissue dilation.

RESULTS

There were 206 males and 208 females with the average age 20.53±12.9 years (age range 1-68 years). The patient proportions in the age groups of 0-20, 21-40 and >40 years were 61.4% (254 cases), 29.2% (121 cases), and 9.4% (39 cases) respectively. The patient's attendance rate reached the highest during the summer and winter. Most patients were from the rural areas with an increasing tendency each year. The burn scars were the most abundant and the injury sites were mostly the head and face. Univariate analysis showed that the time from scarring to the surgical treatment and the injury sites were significantly influenced the scar surgical treatment efficacy. Logistic regression analysis demonstrated that the injured sites of the head and face significantly influenced the scar surgical treatment efficacy.

CONCLUSION

With the development of economy in China, more scar patients especially younger and children visit doctors predominantely from the rural areas. Usually, they get their scars in the exposed area of their bodies (head and face) which seriously affect the patient's appearance and function. Factors influencing the scar surgical treatment efficacy has important clinical significance of prevention and treatment.

Effects of atmospheric parameters on radon measurements using alpha-track detectors

The calibration factors of alpha-track radon detectors (ATDs) are essential for accurate determination of indoor radon concentrations. In this paper, the effects of atmospheric parameters on the calibration factors were theoretically studied and partially testified. Based on the atmospheric thermodynamics theory and detection characteristics of the allyl diglycol carbonate (CR-39), the calibration factors for 5 types of ATDs were calculated through Monte Carlo simulations under different atmospheric conditions. Simulation results showed that the calibration factor increased by up to 31% for the ATDs with a decrease of air pressure by 35.5 kPa (equivalent to an altitude increase of 3500 m), and it also increased by up to 12% with a temperature increase from 5 °C to 35 °C, but it was hardly affected by the relative humidity unless the water-vapor condensation occurs inside the detectors. Furthermore, it was also found that the effects on calibration factors also depended on the dimensions of ATDs. It indicated that variations of the calibration factor with air pressure and temperature should be considered for an accurate radon measurement with a large dimensional ATD, and water-vapor condensation inside the detector should be avoided in field measurements.

Note: phase retrieval method for analyzing single-phase displacement interferometry data

We present a phase retrieval method (PRM) for analyzing single-phase displacement interferometry measurements on rapidly changing velocity histories, including photon Doppler velocimetry (PDV). PRM identifies the peaks and valleys as well as zero-crossing points in a PDV time series, performs normalization and extracts point-by-point phase and thus velocity information. PRM does not require a wide time window as in sliding window Fourier transformation, and thus improves the effective temporal resolution. This method is implemented in analyzing PDV data obtained from gas gun experiments, and validated against simultaneous measurements with velocity interferometer system for any reflector.

Effects of AlGaAs cladding layers on the luminescence of GaAs/GaAs1-xBix/GaAs heterostructures

The structural and optical properties of GaAs1-xBix quantum wells (QWs) symmetrically clad by GaAs barriers with and without additional confining AlGaAs layers are studied. It is shown that a GaAs/GaAs1-xBix/GaAs QW with x ~ 4% and well width of ~ 4 nm grown by molecular beam epitaxy demonstrates efficient photoluminescence (PL) that becomes significantly more thermally stable when a cladding AlGaAs layer is added to the QW structure. The PL behavior for temperatures between 10 and 300 K and for excitation intensities varying by seven orders of magnitude can be well described in terms of the dynamics of excitons including carrier capture in the QW layer, thermal emission and diffusion into the cladding barriers. Understanding the role of these processes in the luminescence of dilute GaAs1-xBix QW structures facilitates the creation of highly efficient devices with reduced thermal sensitivity and low threshold current.

A set of microRNAs mediate direct conversion of human umbilical cord lining-derived mesenchymal stem cells into hepatocytes

In a previous study, we elucidated the specific microRNA (miRNA) profile of hepatic differentiation. In this study, we aimed to clarify the instructive role of six overexpressed miRNAs (miR-1246, miR-1290, miR-148a, miR-30a, miR-424 and miR-542-5p) during hepatic differentiation of human umbilical cord lining-derived mesenchymal stem cells (hMSCs) and to test whether overexpression of any of these miRNAs is sufficient to induce differentiation of the hMSCs into hepatocyte-like cells. Before hepatic differentiation, hMSCs were infected with a lentivirus containing a miRNA inhibitor sequence. We found that downregulation of any one of the six hepatic differentiation-specific miRNAs can inhibit HGF-induced hepatic differentiation including albumin expression and LDL uptake. Although overexpression of any one of the six miRNAs alone or liver-enriched miR-122 cannot initiate hepatic differentiation, ectopic overexpression of seven miRNAs (miR-1246, miR-1290, miR-148a, miR-30a, miR-424, miR-542-5p and miR-122) together can stimulate hMSC conversion into functionally mature induced hepatocytes (iHep). Additionally, after transplantation of the iHep cells into mice with CCL4-induced liver injury, we found that iHep not only can improve liver function but it also can restore injured livers. The findings from this study indicate that miRNAs have the capability of directly converting hMSCs to a hepatocyte phenotype in vitro.

Thrombotic risk factors in Chinese Budd-Chiari syndrome patients. An observational study with a systematic review of the literature

In Western countries, thrombotic risk factors for Budd-Chiari syndrome (BCS) are very common, including factor V Leiden mutation, prothrombin G20210A mutation, myeloproliferative neoplasms, paroxysmal nocturnal haemoglobinuria, etc. However, the data regarding thrombotic risk factors in Chinese BCS patients are extremely limited. An observational study was conducted to examine this issue. A total of 246 BCS patients who were consecutively admitted to our department between July 1999 and December 2011 were invited to be examined for thrombotic risk factors. Of these, 169 patients were enrolled. Neither factor V Leiden mutation nor prothrombin G20210A mutation was found in any of 136 patients tested. JAK2 V617F mutation was positive in four of 169 patients tested. Neither MPL W515L/K mutation nor JAK2 exon 12 mutation was found in any of 135 patients tested. Overt myeloproliferative neoplasms were diagnosed in five patients (polycythemia vera, n=3; essential thrombocythemia, n=1; idiopathic myelofibrosis, n=1). Two of them had positive JAK2 V617F mutation. Both CD55 and CD59 deficiencies were found in one of 166 patients tested. This patient had a previous history of paroxysmal nocturnal haemo-globinuria before BCS. Anticardiolipin IgG antibodies were positive or weakly positive in six of 166 patients tested. Hyperhomocysteinaemia was found in 64 of 128 patients tested. 5,10-methylenetetrahydrofolate reductase C677T mutation was found in 96 of 135 patients tested. In conclusion, factor V Leiden mutation, prothrombin G20210A mutation, myeloproliferative neoplasms, and paroxysmal nocturnal haemoglobinuria are very rare in Chinese BCS patients, suggesting that the etiological distribution of BCS might be different between Western countries and China.

Ethylene Formation by Catalytic Dehydration of Ethanol with Industrial Considerations

Ethylene is the primary component in most plastics, making it economically valuable. It is produced primarily by steam-cracking of hydrocarbons, but can alternatively be produced by the dehydration of ethanol, which can be produced from fermentation processes using renewable substrates such as glucose, starch and others. Due to rising oil prices, researchers now look at alternative reactions to produce green ethylene, but the process is far from being as economically competitive as using fossil fuels. Many studies have investigated catalysts and new reaction engineering technologies to increase ethylene yield and to lower reaction temperature, in an effort to make the reaction applicable in industry and most cost-efficient. This paper presents various lab synthesized catalysts, reaction conditions, and reactor technologies that achieved high ethylene yield at reasonable reaction temperatures, and evaluates their practicality in industrial application in comparison with steam-cracking plants. The most promising were found to be a nanoscale catalyst HZSM-5 with 99.7% ethylene selectivity at 240 °C and 630 h lifespan, using a microreactor technology with mechanical vapor recompression, and algae-produced ethanol to make ethylene.

Meta-analysis: effect of preoperative infliximab use on early postoperative complications in patients with ulcerative colitis undergoing abdominal surgery

BACKGROUND

Infliximab is widely used in severe and refractory ulcerative colitis (UC). The results of clinical studies are inconsistent on whether preoperative infliximab use increases early postoperative complications in UC patients.

AIM

To determine the clinical safety and efficacy of preoperative infliximab treatment in UC patients with regard to short-term outcomes following abdominal surgery.

METHODS

PubMed, Embase databases were searched for controlled observational studies comparing postsurgical morbidity in UC patients receiving infliximab preoperatively with those not on infliximab. The primary endpoint was total complication rate. Secondary endpoints included the rate of infectious and non-infectious complications. We calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs) as summary measures.

RESULTS

A total of 13 studies involving 2933 patients were included in our meta-analysis. There was no significant association between infliximab therapy preoperatively and total (OR = 1.09, 95% CI: 0.87-1.37, P = 0.47), infectious (OR = 1.10, 95% CI: 0.51-2.38, P = 0.81) and non-infectious (OR = 1.10, 95% CI: 0.76-1.59, P = 0.61) postoperative complications respectively. Infliximab might be a protective factor against infection for the use within 12 weeks prior to surgery (OR = 0.43, 95% CI: 0.22-0.83, P = 0.01). No publication bias was found.

CONCLUSION

Preoperative infliximab use does not increase the risk of early postoperative complications in patients with ulcerative colitis undergoing abdominal surgery.

The importance of orthotopic implantation to the isolation and biological characterization of a metastatic human clear cell renal-carcinoma in nude-mice

We established a new human renal cell carcinoma system to study some properties of metastatic renal cancer cells and the influence of the organ environment on their metastatic potential. Renal cell carcinoma obtained from a surgical specimen was dissociated enzymatically. Cells were injected into the subcutis, kidney, cecal wall, and spleen of nude mice. Tumors grew in the subcutis and kidney. Only kidney tumors produced distant metastasis. Subcutaneous tumors were avascular and encapsulated, whereas kidney tumors were highly vascularized and invaded the kidney parenchyma. Cell lines were also established from several spontaneous lung metastases. The most metastatic cell line (LM-6) expressed higher levels of basic fibroblast growth factor, gelatinase, and urokinase activity. These results show that human neoplasms are heterogeneous for biologic properties, that orthotopic implantation is essential for the selection, growth, and metastasis of human renal cell carcinoma cells, and that metastatic cells must possess multiple properties to enable them to complete the process.

Critical factors regulating site-specific brain metastasis of murine melanomas

The intracarotid injection of B16 melanoma cells syngeneic to C57BL/6 mice and K-1735 melanoma cells syngeneic to C3H/HeN mice results in site-specific brain metastasis in C57BL/6 x C3H/HeN F1 mice. The K-1735 cells produce lesions only in the brain parenchyma, whereas the B16 cells produce lesions only in the meninges and ventricles. To determine the mechanisms that regulate this site-specific brain metastasis, we transfected the melanoma cells with DNA from plasmids pSV2neo or pSV2hvgro, which confer resistance to the drugs neomycin and hygromycin, respectively. Hybrids between the B16 and K-1735 cells were obtained by fusion. Cells of the K-1735 x K-1735 hybrid produced lesions only in the brain parenchyma of C57BL/6 x C3H/HeN F1 mice, whereas all B16 x K-1735 hybrids produced lesions only in the meninges and the ventricles. Initial cell arrest in the meninges or the brain parenchyma, production of collagenolytic activity, motility, and expression of CD44 did not predict or correlate with site-specific brain metastasis. The response of the different melanomas and hybrid cells to transforming growth factor-beta (TGF-beta) correlated with growth in the brain parenchyma. B16 cells and B16 x K-1735 hybrids bound more TGF-beta than K-1735 cells. The in vitro growth of B16 cells and all B16 x K-1735 hybrid cells was significantly inhibited by TGF-beta1 and TGF-beta2, whereas the growth of K-1735 cells and K-1735 x K-1735 hybrids was enhanced. Since TGF-beta is abundant in brain tissue, the results suggest that the ability of melanoma cells to proliferate in the brain parenchyma determines the production of site-specific brain metastasis.

Modulation of Doxorubicin sensitivity and level of p-glycoprotein expression in human colon-carcinoma cells by ectopic and orthotopic environments in nude-mice

The purpose of the study was to determine whether the organ environment can influence the response of colon cancer cells to chemotherapy. The highly metastatic human colon cancer cell line KM12L4, previously selected for production of liver metastases in nude mice, was injected into the cecal wall and into the spleen to produce liver metastases, and into the subcutis of nude mice. Doxorubicin (DOX) at 10 mg/kg or saline (control) was injected intravenously on days 7 and 16 after tumor cell injection. The in vivo response of tumors growing in the cecum, liver, and subcutaneous (s.c.) sites as well as the DOX sensitivity of cell lines established from liver and s.c. tumors were compared. Colon cancers growing s.c. were more sensitive to DOX than tumors growing in the cecal wall or liver of nude mice. The difference in response to DOX between s.c. tumors (sensitive) and liver tumors (resistant) was not due to selection of cell populations with different sensitivity to DOX, or differences in DOX distribution. PKC activity was lower in tumors of the liver and the cecum than in s.c. tumors. The expression of P-glycoprotein as determined by flow cytometric analysis of tumor cells harvested from lesions in different organs correlated inversely with their sensitivity to DOX. Increased levels of P-glycoprotein correlated with mdr-1, mdr-3 mRNA expression as determined by Northern analysis. Collectively, the data show that the organ environment influences the response of human colon carcinoma cells to DOX and recommend that animal models of this disease for experimental therapeutic studies employ orthotopic implantation of tumor cells.

Cell density-dependent regulation of mdr-1 gene expression in murine colon cancer cells

We studied the regulation of mdr-1 and P-glycoprotein in sparse and confluent cultures of murine CT-26 colon carcinoma cells. The expression level of mdr-1 mRNA transcripts (analyzed by Northern blot and in situ hybridization) and P-glycoprotein (analyzed by flow cytometry) inversely correlated with cell density. The modulation of mdr gene expression in sparse and confluent cells was not related to cell division, nutrient depletion, inhibition of protein synthesis, gap junction status, extracellular ATP, or the presence of various extracellular matrixes, but may be related to cell-density and cell-contact mediated changes in phosphatase activity. The confluence-mediated downmodulation of mdr-1 increased the chemosensitivity of the cells to several anticancer drugs commonly associated with an in vitro MDR phenotype by increasing the intracellular accumulation of the drugs. These data may explain some of the discrepancies in results obtained when analyzing mdr gene expression in tumors growing in vivo or in vitro, and why mdi expression in tumors is localized to the periphery of the lesions.

CM2 antigen, a potential novel molecule participating in glucuronide transport on rat hepatocyte canalicular membrane

The polarized molecules predominately distributing at hepatocyte canalicular surface play a vital role in disclosing the process of bile formation and etiopathogenisis of cholestatic live diseases. Therefore, it is important to find novel polarized molecules on hepatocyte canalicular membrane. In the present study, canalicular membrane vesicles (CMVs) isolated from rat hepatocyte by density gradient centrifugation were used as immunogens to produce hybridoma and 46 strains of monoclonal antibodies (mAb) against CMVs were obtained. With a series of morphological assay methods, including immunohistochemistry, immunofluorescence and immuno-electron microscope, the antigens recognized by canalicular mAb1 (CM1) and canalicular mAb2 (CM2) were confirmed to predominately distribute at hepatocyte canalicular membrane. Transport activity assay revealed that CM2 could inhibit ATP-dependent E217βG uptake of rat hepatocyte CMVs. Meanwhile, Western blotting analysis showed that the molecular mass of CM2 antigen was approximately 110kDa, which was much less than Mr 180kDa of multidrug resistance-associated protein 2 (MRP2) involved in glucuronide transport. These data indicated that CM2 antigen might be a potential novel molecule participating in glucuronide transport on the hepatocyte canalicular membrane.

MicroRNA-7 functions as an anti-metastatic microRNA in gastric cancer by targeting insulin-like growth factor-1 receptor

Metastasis is a major clinical obstacle in the treatment of gastric cancer (GC) and it accounts for the majority of cancer-related mortality. MicroRNAs have recently emerged as regulators of metastasis by acting on multiple signaling pathways. In this study, we found that miR-7 is significantly downregulated in highly metastatic GC cell lines and metastatic tissues. Both gain-of-function and loss-of-function experiments showed that increased miR-7 expression significantly reduced GC cell migration and invasion, whereas decreased miR-7 expression dramatically enhanced cell migration and invasion. In vivo metastasis assays also demonstrated that overexpression of miR-7 markedly inhibited GC metastasis. Moreover, the insulin-like growth factor-1 receptor (IGF1R) oncogene, which is often mutated or amplified in human cancers and functions as an important regulator of cell growth and tumor invasion, was identified as a direct target of miR-7. Silencing of IGF1R using small interefering RNA (siRNA) recapitulated the anti-metastatic function of miR-7, whereas restoring the IGF1R expression attenuated the function of miR-7 in GC cells. Furthermore, we found that suppression of Snail by miR-7, through targeting IGF1R, increased E-cadherin expression and partially reversed the epithelial-mesenchymal transition (EMT). Finally, analyses of miR-7 and IGF1R levels in human primary GC with matched lymph node metastasis tissue arrays revealed that miR-7 is inversely correlated with IGF1R expression. The present study provides insight into the specific biological behavior of miR-7 in EMT and tumor metastasis. Targeting this novel miR-7/IGF1R/Snail axis would be helpful as a therapeutic approach to block GC metastasis.

Transgastric endoscopic gastroenterostomy using a partially covered occluder: a canine feasibility study

BACKGROUND AND STUDY AIMS

The use of natural orifice transluminal endoscopic surgery (NOTES) for gastroenterostomy has been previously reported, but it remains technically challenging and additional assistance is often needed. The aim of this study was to develop and evaluate a novel method for the creation of a gastroenterostomy using NOTES with an occluder.

METHODS

Transgastric endoscopic gastroenterostomy was performed in 12 healthy female dogs using a therapeutic upper gastrointestinal endoscope and a partially covered occluder. The occluder was removed with a snare 1 week later. The patency of the gastroenterostomy was confirmed by endoscopy, contrast radiological study, necropsy, and histological examination after 2 weeks.

RESULTS

NOTES gastroenterostomy with an occluder was successful in all 12 dogs. The mean operative time was 32.3 ± 10.3 min (range 20.3 - 53.5). One dog (the first; 8.3 %) died 4 days after the operation of severe intra-abdominal infection due to incorrect deployment of the occluder and poor bowel preparation. Minor bleeding occurred at the anastomosis after removal of the occluder in two of the remaining dogs (18.2 %). Necropsy revealed postoperative adhesions that had developed at the anastomotic site in one dog (9.1 %). No anastomotic leakage or intestinal obstruction was observed. Complete healing of the anastomosis was confirmed on histological evaluation.

CONCLUSION

Gastroenterostomy performed entirely by NOTES using an occluder was technically feasible in this survival animal model.

Big roles of microRNAs in tumorigenesis and tumor development

MicroRNAs (miRNAs) are a class of endogenous non-protein-coding small RNAs that are evolutionarily conserved and widely distributed among species. Their major function is to negatively regulate target gene expression. A single miRNA can regulate multiple target genes, indicating that miRNAs may regulate multiple signaling pathways and participate in a variety of physiological and pathological processes. Currently, approximately 50% of identified human miRNA-coding genes are located at tumor-related fragile chromosome regions. Abnormal miRNA expression and/or mutations have been found in almost all types of malignancies. These abnormally expressed miRNAs play roles similar to tumor suppressor genes or oncogenes by regulating the expression and/or function of tumor-related genes. Therefore, miRNAs, miRNA target genes, and the genes regulating miRNAs form a regulatory network with miRNAs in the hub. This network plays a pivotal role in tumorigenesis and tumor development.

Meta-analysis: the significance of screening for JAK2V617F mutation in Budd-Chiari syndrome and portal venous system thrombosis

BACKGROUND

It is important to evaluate whether screening for JAK2V617F mutation should be routinely performed in patients with Budd-Chiari syndrome (BCS) and portal venous system thrombosis (PVST). However, the prevalence of JAK2V617F mutation in such patients is substantially varied, and its association with development of myeloproliferative disorders (MPD) is deficiently identified.

AIMS

To estimate the prevalence of JAK2V617F mutation and to explore the significance of screening for JAK2V617F mutation in these patients.

METHODS

All observational studies regarding the prevalence of JAK2V617F mutation in patients with BCS and PVST were identified via PubMed and MEDLINE databases. Primary items were the proportions of JAK2V617F mutation and MPD.

RESULTS

Twenty-three studies fulfilled the inclusion criteria. Regardless of underlying aetiological factors, the pooled prevalence of JAK2V617F mutation was 37% and 24% in patients with BCS and PVST respectively. After pre-existing MPD was excluded, the pooled prevalence was decreased to 26% and 19%. Heterogeneity among studies was significant for the prevalence of JAK2V617F mutation. Compared with healthy subjects and patients with thrombosis in other sites, the prevalence of JAKV617F mutation was significantly higher in patients with BCS and PVST. The prevalence of MPD was significantly higher in patients with JAK2V617F mutation than those without.

CONCLUSIONS

JAK2V617F mutation is frequently found in patients with BCS and PVST, but there is a huge variation of prevalence among the included studies. Additionally, it is more specific to thrombosis in splanchnic areas and strongly associated with the development of MPD in these patients. Further studies are needed to evaluate whether the screening test should be widely performed in Asian countries and cirrhotic patients.

A reproducible route to p-ZnO films and their application in light-emitting devices

Although great efforts have been made, reproducible p-type doping is still one of the largest hurdles that hinders the optoelectronic applications of ZnO. In this Letter, a reproducible route to p-type ZnO films employing lithium-nitrogen as a dual-acceptor dopant has been demonstrated, and p-i-n structured light-emitting devices (LEDs) have been constructed. Obvious purple emissions have been observed from the LEDs, confirming the applicability of the p-type ZnO films in optoelectronic devices. The results reported in this Letter provide a reproducible route to p-type ZnO films, and thus may lay a solid ground for future optoelectronic applications of ZnO.

Up-regulated expression of Notch1 and Jagged1 in human colon adenocarcinoma

Deregulated expression of Notch molecules is observed in many malignant tumors, however, the expression of Notch1 and Jagged1 in colon adenocarcinoma is still unknown. This study is to investigate the expression of Notch1 and Jagged1 in human colon adenocarcinoma. Sixty-five human colon adenocarcinoma and 60 adjacent nontumor colon tissue sections were detected by immunohistochemistry. Ten paired fresh surgical human colon adenocarcinoma and adjacent nontumor colon samples were analyzed by Western blot and RT-PCR. Both Notch1 and Jagged1 were expressed in the cytoplasm of neoplastic cells of colon adenocarcinoma tissue. The protein and mRNA levels of both molecules were higher in colon adenocarcinoma than in adjacent nontumor tissue. Moreover, Notch1 was positively correlated with tumor stage. This investigation demonstrates that Notch1 and Jagged1 are up-regulated in human colon adenocarcinoma and suggests that Notch1/Jagged1 signaling might play a role in the development of colon adenocarcinoma.

Growth of nanocrystals and thin films at the water-oil interface

The use of the water-oil interface provides significant advantages in the synthesis of inorganic nanostructures. Employing the water-toluene interface, luminescent CdS nanocrystals have been obtained at a relatively modest temperature of 35 degrees C. The diameters of the particulates can be varied between 1.0 and 5.0 nm. In addition, we have devised a new method for transferring thin films at the water-toluene interface onto solid substrates. Using this method, thin films consisting of Au and Ag nanocrystals spread over very large areas (square centimetres) are obtained in a single step. These films are directly usable as ingredients of functional devices. We show this by constructing a working amine sensor based on films of Au nanocrystals. The materials obtained have been characterized by X-ray diffraction, scanning and transmission electron microscopy, absorption and emission spectroscopy and charge transport measurements.

MicroRNA dysregulation in gastric cancer: a new player enters the game

Gastric carcinogenesis is a multistep process involving genetic and epigenetic alteration of protein-coding proto-oncogenes and tumor-suppressor genes. Recent discoveries have shed new light on the involvement of a class of noncoding RNA known as microRNA (miRNA) in gastric cancer. A substantial number of miRNAs show differential expression in gastric cancer tissues. Genes coding for these miRNAs have been characterized as novel proto-oncogenes and tumor-suppressor genes based on findings that these miRNAs control malignant phenotypes of gastric cancer cells. In this connection, miRNA dysregulation promotes cell-cycle progression, confers resistance to apoptosis, and enhances invasiveness and metastasis. Moreover, certain polymorphisms in miRNA genes are associated with increased risks for atrophic gastritis and gastric cancer, whereas circulating levels of miRNAs may serve as biomarkers for early diagnosis. Several miRNAs have also been shown to correlate with gastric cancer progression, and thus may be used as prognostic markers. Elucidating the biological aspects of miRNA dysregulation may help us better understand the pathogenesis of gastric cancer and promote the development of miRNA-directed therapeutics against this deadly disease.

Meta-analysis: polymorphisms in TNF-alpha gene promoter and Crohn's disease

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) is involved in the pathogenesis of Crohn's disease (CD). However, results on the association between the polymorphisms in TNF-alpha promoter and the risk of CD are inconsistent.

AIM

To perform a quantitative synthesis for the genetic polymorphisms in TNF-alpha promoter and CD risk.

METHODS

Databases were searched (up to 2009) and 31 studies were included. Risks of CD associated with the polymorphisms in TNF-alpha promoter were assessed.

RESULTS

Overall, individuals with -1031 TC+CC genotype had a slightly increased risk to develop CD compared with individuals with -1031 TT genotype (OR, 1.32; 95% CI, 1.03-1.70). In the further stratified analysis, we found Asians with the -1031T>C, -863 C>A and -857 C>T variant polymorphisms have almost one and a half CD risk compared with other genotypes (OR, 1.58; 95% CI, 1.16-2.15; OR, 1.55; 95% CI, 1.18-2.02; OR, 1.54; 95% CI, 1.19-1.99 respectively). We did not find -308 G>A variant associated with CD location and disease behaviours in stratified analysis.

CONCLUSIONS

TNF-alpha polymorphisms in the promoter region might be used as a biomarker for CD risk prediction. Larger studies with mixed ethnicity subjects and stratified by clinical and sub clinical characteristics are needed to validate our findings.

Apatite reduces amelogenin proteolysis by MMP-20 and KLK4 in vitro

Two enamel proteases, matrix metalloproteinase-20 (MMP-20) and kallikrein 4 (KLK4), are known to cleave amelogenin and are necessary for proper enamel formation. However, the effect of hydroxyapatite (HAP) on the proteolytic activity of these enzymes remains unclear. To investigate whether apatite affects normal amelogenin proteolysis, we used 2 different isoforms of amelogenin combined with the appropriate enzymes to analyze proteolytic processing rates in the presence or absence of synthetic hydroxyapatite (HAP) crystals (N = 3). We found a distinct dose-dependent relationship between the amount of HAP present in the proteolysis mixture and the rate of rP172 degradation by rpMMP-20, whereas the effect of HAP on proteolysis of either rP172 or rP148 by rhKLK4 was less prominent.

Meta-analysis: pre-operative infliximab treatment and short-term post-operative complications in patients with ulcerative colitis

BACKGROUND

Infliximab was approved for use in ulcerative colitis in recent years. It has been debated if infliximab increases the risk of post-operative complications in patients with ulcerative colitis.

AIM

To perform a meta-analysis that examines the relationship between preoperative infliximab treatment and short-term post-operative complications in patients with ulcerative colitis.

METHODS

We searched the PubMed and MEDLINE databases to identify observational studies on the impact of pre-operative infliximab use on short-term post-operative complications in ulcerative colitis. Infectious complications mainly included wound infection, sepsis and abscess, whereas non-infectious complications included intestinal obstruction, thromboembolism and gastrointestinal haemorrhage. Pooled odds ratios (ORs) were calculated for each relationship.

RESULTS

A total of 5 studies and 706 patients were included in our meta-analysis. Overall, we did not find a strong association between pre-operative treatment of infliximab and short-term infectious [OR 2.24, 95% confidence interval (CI) 0.63-7.95] or non-infectious (OR 0.85, 95% CI 0.50-1.45) post-operative complications in ulcerative colitis patients. On the contrary, we discovered that pre-operative infliximab use increased short-term total post-operative complications (OR 1.80, 95% CI 1.12-2.87).

CONCLUSIONS

Pre-operative infliximab use increased the risk of short-term post-operative complications. Subgroup analysis is underpowered to assess the nature of these complications but shows a trend towards increased post-operative infection.

Poly(amidoamine) dendrimer-supported organoplatinum antitumour agents

While numerous water-soluble biocompatible polymers have been utilized for the construction of drug conjugates that offer significant advantages for drug delivery, poly(amidoamine) (PAMAM) dendrimers are superior in many ways for this purpose. They display nanoscale size, uniform shape, excellent water solubility, low toxicity and high surface functionality. In an attempt to circumvent the toxic side effects associated with the administration of organoplatinum drugs, a polymeric prodrug has been prepared from the treatment of a generation 4.5 PAMAM dendrimer with diaquo(1,2-diaminocyclohexane)platinum(II). A well-defined dendrimer–platinum conjugate containing 40 (1,2-diaminocyclohexane)platinum(II) units coordinated to the dendrimer surface via carboxylate groups is formed. This adduct is well behaved, water soluble, contains a high loading of platinum moieties and displays sustained release of active platinum species over a 24 h period under physiological conditions.

Enamel proteases reduce amelogenin-apatite binding

Organic matrix degradation and crystal maturation are extracellular events that occur simultaneously during enamel biomineralization. We hypothesized that enamel proteases control amelogenin-mineral interaction, which, in turn can affect crystal nucleation, organization, and growth. We used a recombinant amelogenin (rP172), a homolog of its major cleavage product (rP148), and a native amelogenin lacking both N- and C-termini (13k). We compared apatite binding affinity between amelogenins and their digest products during proteolysis. We further compared binding affinity among the 3 amelogenins using a Langmuir model for protein adsorption. Amelogenin-apatite binding affinity was progressively reduced with the proteolysis at the C- and N- termini by recombinant pig MMP-20 (rpMMP20) and recombinant human kallikrein-4 (rhKLK4), respectively. The binding affinity of amelogenin to apatite was found to be in the descending order of rP172, rP148, and 13k. Analysis of our data suggests that, before its complete degradation during enamel maturation, stepwise processing of amelogenin by MMP-20 and then KLK4 reduces amelogenin-apatite interaction.

Computer-aided applications of nanoscale smart materials for biomedical applications

Nanotechnology has the potential to impact the treatment of many diseases that currently plague society: cancer, AIDS, dementia of various kinds and so on. Nanoscale smart materials, such as carbon nanotubes, C60, dendrimers and cyclodextrins, hold great promise for use in the development of better diagnostics, drug delivery and the alteration of biological function. Although experimentation is being used to explore the potential offered by these materials, it is by its very nature expensive in terms of time, resources and expertise. Insight with respect to the behavior of these materials in the presence of biological entities can be obtained much more rapidly by molecular dynamics simulation. Furthermore, the results of simulation may be used to guide experimentation so that it is much more productive than it might be in the absence of such information. The interactions of several nanoscale structures with biological macromolecules can already be probed effectively using molecular dynamics simulation. The results obtained should form the basis for significant new developments in the treatment of disease.

Controlled trials in hepatitis B virus-related decompensate liver cirrhosis: peripheral blood monocyte transplant versus granulocyte-colony-stimulating factor mobilization therapy

BACKGROUND

Liver cirrhosis represents the end stage of chronic liver injury. Currently, liver transplantation provides the only definite cure but it is beset with many problems, including lack of donors and risk of rejection. Stem cell therapy is very attractive in this setting because it has the potential to help tissue regeneration. In this study, we aimed to investigate the therapeutic effect of peripheral blood monocyte cell (PBMC) transplantation in decompensated liver cirrhosis.

METHODS

A total of 40 subjects (31 men and nine females, age range 21-71 years) was recruited to two groups. Group 1 received granulocyte-colony-stimulating factor (G-CSF) mobilization, PBMC collection by leukapheresis and PBMC transplant therapy. Group 2 received G-CSF mobilization for 4 days. At baseline and 6 months after treatment, liver function of the two groups was monitored by blood examination and ultrasonagraphy.

RESULTS

Both groups gained significant improvement in liver synthetic function, such as serum albumin and prothrombin time, from baseline to 6 months after treatment (P<0.01). However, there was no significant difference in alanine aminotransferase, aspartate aminotransferase and total bilirubin in both groups (P>0.05). Compared with group 2, a significantly improved liver function was observed in group 1, including elevated serum albumin level and a decreased CTP score (P<0.05). No major adverse effects were noted.

DISCUSSION

Autologous PBMC transplantation could be considered as a novel and alternative treatment for patients with decompensated liver cirrhosis.

Elevated plasma osteopontin level is predictive of cirrhosis in patients with hepatitis B infection

BACKGROUND

Osteopontin (OPN) was shown to play an important role in the pathogenesis of various inflammatory and fibrotic processes and elevated in fibrotic liver of mouse model. However, the significance of OPN in hepatitis B virus (HBV)-induced liver cirrhosis (LC) remains unclear and is therefore evaluated in this study.

METHODS

Thirty-nine patients with HBV-induced LC, 30 patients with HBV infection but without cirrhosis, 11 patients with HBV-related hepatocellular carcinoma (HCC) and 14 additional healthy controls were enrolled in this study. Plasma levels of OPN were measured with enzyme-linked immunosorbent assay and the relationship between OPN and clinical parameters was evaluated.

RESULTS

When compared to HBV infection group (median 2.16 ng/ml), plasma levels of OPN were significantly increased in cirrhosis (4.52 ng/ml, p < 0.001) and cancer group (13.38 ng/ml, p < 0.001). The OPN level was correlated with the severity of liver damage according to Child-Pugh classification (p = 0.003). It showed at least comparable sensitivity and specificity to predict cirrhosis as aspartate aminotransferase to platelet ratio index, a previously established non-invasive serum marker of cirrhosis.

CONCLUSIONS

These data suggest that OPN could be used to evaluate the existence of LC, as OPN has previously been reported to be increased in the HCC; this unique feature makes OPN a promising candidate for prediction biomarker in the long-time surveillance of patients with HBV infection to evaluate the risk of cirrhosis and cancer.

[Hypoxia induced HIF-1 accumulation and VEGF expression in gastric epithelial mucosa cell: involvement of ERK1/2 and PI3K/Akt]

Hypoxia is a common environmental stress that influences signaling pathways and cells function, which through initiating intracellular signaling pathways and hence leading to the activation of the transcription factor hypoxia-inducible factor-1 (HIF-1). In this study, we initially confirm that hypoxia activates HIF-1alpha protein expression in a time-dependent manner with a maximum reached at 60 min in vitro and 4h in vivo in gastric mucosa epithelial cells. The expression of HIF-1alpha is correlated with the activation of HIF-1 DNA binding and transcriptional activity. Hypoxia dose not affect HIF-1alpha mRNA transcription but regulates HIF-1alpha protein expression through a translation-dependent pathway to regulate protein synthesis. Hypoxia could induce phosphorylation of Akt, MAPK (ERK), and target of p70S6K1. PI3K and MAPK inhibitor, LY294002 and U0126 could inhibit hypoxia-induced HIF-1 and VEGF expression. We also investigated the role of reactive oxygen species (ROS) involved in HIF-1 and VEGF expression Exogenous addition of H2O2 was sufficient to activate Akt and ERK, scavengers of H2O2 significantly inhibited hypoxia-induced Akt and ERK, and subsequent HIF-lax expression and transcriptional activity. In conclusion, our data suggested that hypoxia- PI3K signaling through Akt and ERK kinases regulated ROS-dependent, hypoxia- induced HIF-1 activation and VEGF expression in gastric mucosa epithelial cells.