[Effect of recombinant human thrombin for hemostasis in liver resection: a randomized controlled phase â ¢ clinical trial].

Objective: To evaluate the hemostatic efficacy, safety and immunogenicity of recombinant human thrombin in the treatment of liver wounds that still ooze after conventional surgical hemostasis. Methods: A multicenter, stratified randomized, double-blind, placebo-controlled phase Ⅲ trial with a planned enrollment of 510 subjects at 33 centers, with a 2∶1 randomization to the thrombin group versus the placebo group. An interim analysis will be conducted after approximately 70% of the subjects have completed the observation period. The primary efficacy endpoint was the rate of hemostasis within 6 minutes at the point of bleeding that could be evaluated. Safety analysis was performed one month after surgery, and the positive rates of anti-drug antibody (ADA) and neutralizing antibody were evaluated. Results: At the interim analysis, a total of 348 subjects had been randomized and received the study drug (215 were male and 133 were female). They were aged 19-69 (52.9±10.9)years. Among them, 232 were in the thrombin group and 116 were in the placebo group, with balanced and comparable demographics and baseline characteristics between the two groups. The hemostasis rate at 6 minutes was 71.6% (95%CI:65.75%-77.36%) in the thrombin group and 44.0% (95%CI: 34.93%-53.00%) in the placebo group, respectively (P<0.001). No grade≥3 drug-related adverse events and no drug-related deaths were reported from the study.No recombinant human thrombin-induced immunologically-enhanced ADA or immunologically-induced ADA was detected after topical use in subjects. Conclusion: Recombinant human thrombin has shown significant hemostatic efficacy and good safety in controlling bleeding during liver resection surgery, while also demonstrating low immunogenicity characteristics.

Pro-arrhythmic effects of gain-of-function potassium channel mutations in the short QT syndrome.

The congenital short QT syndrome (SQTS) is a rare condition characterized by abbreviated rate-corrected QT (QTc) intervals on the electrocardiogram and by increased susceptibility to both atrial and ventricular arrhythmias and sudden death. Although mutations to multiple genes have been implicated in the SQTS, evidence of causality is particularly strong for the first three (SQT1-3) variants: these result from gain-of-function mutations in genes that encode K+ channel subunits responsible, respectively, for the IKr, IKs and IK1 cardiac potassium currents. This article reviews evidence for the impact of SQT1-3 missense potassium channel gene mutations on the electrophysiological properties of IKr, IKs and IK1 and of the links between these changes and arrhythmia susceptibility. Data from experimental and simulation studies and future directions for research in this field are considered. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

[The study of nomogram based on Ishak inflammation score for recurrence of hepatocellular carcinoma after curative resection].

Objective: To investigate the correlation between Ishak inflammation score and the clinicopathological characteristics and recurrence of patients with hepatocellular carcinoma (HCC) after curative resection, and then set up a recurrence nomogram for HCC. Methods: A total of 326 patients with HCC after curative resection from January 2006 to December 2009 were studied retrospectively as training cohort and 110 HCC patients after surgery from January 2010 to December 2012 were used as validation cohort.Clinical follow-up data and peritumoral Ishak inflammation score in training cohort were used to set up a nomogram predicting recurrence of HCC, which was verified by validation cohort. Kaplan-Meier and Cox proportional hazard regression model were used to analyzed accuracy of model prediction. Results: According to Ishak inflammation score, patients were divided into four subgroups: Grade Ⅰ(1-4 scores), Grade Ⅱ(5-8 scores), Grade Ⅲ (9-12 scores) and Grade Ⅳ(13-18 scores). Ishak inflammation score were associated with aspartate transaminase(median 36.0 U/L, P=0.011), γ-glutamyl transpeptidase(median 54.5 U/L, P=0.005), HBV-DNA load(20.5%>10(6) copies/ml, P=0.015) and microvascular invasion(26.7% positive, P=0.021). Multivariate analysis showed that Ishak inflammation score(P=0.007), HBV-DNA load(P<0.01), tumor size(P=0.001) and microvascular invasion(P=0.001) were related with the recurrence of HCC patients.These four risk factors were incorporated into the nomogram.Calibration curves of the nomogram had good agreement between prediction and observation in the probability of recurrence.Both C-indexes and receiver operating characteristic curve analyses revealed that this nomogram had better predictive abilities than those of the AJCC and Barcelona Clinic Liver Cancer (BCLC) stage systems.These results were verified by the validation cohort. Conclusion: A nomogram based on Ishak inflammation score could accurately predict the recurrence of HCC and contribute to HCC relapse surveillance after curative hepatectomy.

[Analysis of prognostic factors of patients with hepatocellular carcinoma after radical resection].

Objective: To explore the prognostic factors of patients with hepatocellular carcinoma(HCC) after radical resection. Methods: From June 2006 to November 2009, preoperative peripheral blood and the clinicopathological data of 208 patients with HCC after curative resection treated in Department of Hepatobiliary Surgery, the First Affiliated Hospital of Chongqing Medical University, were collected and analyzed, including 173 male and 35 female patients with mean age of 53 years. Univariate analyses were applied by the Kaplan-Meier method, and then, significant clinical factors were used for further multivariate analyses by Cox proportional hazard regression model.The patients were divided into low- lymphocyte-monocyte ratio(MLR) group(MLR≤1.2) and high-MLR group(MLR>1.2) according to preoperative MLR. Results: The enrolled 208 patients with median overall survival time for 38 months(1.5-82.2 months), median recurrence-free survival time for 36 months(1.0-82.0 months). Univariate analyses revealed alanine aminotransferase, serum albumin, tumor differentiation, tumor size, TNM stage and clinical stages and MLR might affect the prognosis significantly(all P<0.05), and multiple analyses showed that TNM stage and MLR could influence patients with HCC after radical resection of overall survival time and recurrence-free survival time(all P<0.05). The overall survival time(42.1 months) and recurrence-free survival time(38.1 months) of low-MLR group were longer than high-MLR group(32.7 months and 25.3 months)(both P<0.01). Conclusions: MLR might be associated with prognosis of patients with HCC after curative resection was significantly negative correlation.TNM stage and MLR might be used as an independent prognostic factors for the prognosis of patients with HCC after curative resection.

Clinicopathological features and prognostic factors of rectal gastrointestinal stromal tumors.

AIM: Rectal gastrointestinal stromal tumor (GIST) was a rare disease. This study sought to summarize clinicopathological features and prognostic factors of rectal GISTs. METHODS: Clinicopathological characteristics and prognostic factors of rectal GISTs were investigated by reviewing patients undergoing curative resection at the Fudan University Shanghai Cancer Center between 1986 and 2010. RESULTS: Twenty-one patients, 15 male and 6 female, were included. The mean age of onset was 51 years. The most common initial presentation was hematochezia (7 cases). Eleven patients underwent radical resection, and the other 10 received local resection. No lymph node metastases were identified. All cases were positive for CD117. Seventeen patients were classified as high National Institutes of Health (NIH) risk category. The 5-year disease-free survival (DFS) and overall survival were 33 and 46 %, respectively. Fifteen cases had recurrence postoperatively. Both univariate and multivariate analyses demonstrated the NIH risk category (p = 0.028) and hematochezia symptom (p = 0.014) were independent prognostic factors of the DFS of patients. CONCLUSIONS: Hematochezia was the most common initial symptom. Over 50 % of patients received radical surgery. More than 80 % of patients were at high NIH risk of recurrence. Hematochezia symptom and high NIH risk category indicated poor prognosis of rectal GISTs.

Pharmacological inhibition of the hERG potassium channel is modulated by extracellular but not intracellular acidosis.

INTRODUCTION: Human ether-à-go-go related gene (hERG) is responsible for channels that mediate the rapid delayed rectifier K(+) channel current (I(Kr) ), which participates in repolarization of the ventricles and is a target for some antiarrhythmic drugs. Acidosis occurs in the heart in some pathological situations and can modify the function and responses to drugs of ion channels. The aim of this study was to determine the effects of extracellular and intracellular acidosis on the potency of hERG channel current (I(hERG)) inhibition by the antiarrhythmic agents dofetilide, flecainide, and amiodarone at 37 °C. METHODS AND RESULTS: Whole-cell patch-clamp recordings of I(hERG) were made at 37 °C from hERG-expressing Human Embryonic Kidney (HEK293) cells. Half-maximal inhibitory concentration (IC(50)) values for I(hERG) tail inhibition at -40 mV following depolarizing commands to +20 mV were significantly higher at external pH 6.3 than at pH 7.4 for both flecainide and dofetilide, but not for amiodarone. Lowering pipette pH from 7.2 to 6.3 altered neither I(hERG) kinetics nor the extent of observed I(hERG) blockade by any of these drugs. CONCLUSION: Conditions leading to localized extracellular acidosis may facilitate heterogeneity of action of dofetilide and flecainide, but not amiodarone via modification of hERG channel blockade. Such effects depend on the external pH change rather than intracellular acidification.

Enhanced inhibitory effect of acidosis on hERG potassium channels that incorporate the hERG1b isoform.

Extracellular acidosis occurs in the heart during myocardial ischemia and can lead to dangerous arrhythmias. Potassium channels encoded by hERG (human ether-à-go-go-related gene) mediate the cardiac rapid delayed rectifier K+ current (IKr), and impaired hERG function can exacerbate arrhythmia risk. Nearly all electrophysiological investigations of hERG have centred on the hERG1a isoform, although native IKr channels may be comprised of hERG1a and hERG1b, which has a unique shorter N-terminus. This study has characterised for the first time the effects of extracellular acidosis (an extracellular pH decrease from 7.4 to 6.3) on hERG channels incorporating the hERG1b isoform. Acidosis inhibited hERG1b current amplitude to a significantly greater extent than that of hERG1a, with intermediate effects on coexpressed hERG1a/1b. IhERG tail deactivation was accelerated by acidosis for both isoforms. hERG1a/1b activation was positively voltage-shifted by acidosis, and the fully-activated current-voltage relation was reduced in amplitude and right-shifted (by ∼10 mV). Peak IhERG1a/1b during both ventricular and atrial action potentials was both suppressed and positively voltage-shifted by acidosis. Differential expression of hERG isoforms may contribute to regional differences in IKr in the heart. Therefore inhibitory effects of acidosis on IKr could also differ regionally, depending on the relative expression levels of hERG1a and 1b, thereby increasing dispersion of repolarization and arrhythmia risk.

Secondary resistance to imatinib in patients with gastrointestinal stromal tumors through an acquired KIT exon 17 mutation.

Although imatinib has demonstrated a potent effect on advanced gastrointestinal stromal tumors (GISTs) and has improved the survival of GIST patients, with its prolonged use imatinib resistance is becoming an increasing clinical problem. Mechanisms of secondary resistance are still under investigation. Our study aimed to determine the mechanism of acquired resistance to imatinib in GISTs. Using bidirectional PCR DNA sequencing, we sequenced exons 9, 11, 13 and 17 of the KIT gene and exons 12 and 18 of the PDGFRA gene in secondary resistant lesions obtained from 18 GIST patients after treatment with imatinib. Fourteen of 18 cases carried activating mutations in the KIT gene, with a mutation encoding the juxtamembrane domain present in exon 11 in 12 cases, in exon 13 in 1 case, and in exon 9 in 1 case. In 4 of 10 imatinib-resistant patients, an identical novel missense mutation (T2467G) was found in exon 17, resulting in a substitution of tyrosine by aspartic acid at codon 823 (Y823D). In conclusion, the exon 17 missense mutation T2467G in the tyrosine kinase domain of the KIT gene is correlated with imatinib resistance.

[Separation and determination of 1,5-benzothiazepines-alpha-chloro-beta-lactam with thin-layer chromatography].

A method for separation and determination of 1,5-benzothiazepines-alpha-chloro-beta-lactam in reaction mixture by thin-layer chromatography has been established. The operating conditions were: lambda 1 = 270 nm, lambda 2 = 310 nm, beam size: 1.2 mm x 1.2 mm, SX = 3. The calibration curve was linear in the range of 0.285-5.7 micrograms (r = 0.9952, n = 8) and the detectable limit was 0.114 microgram. The coefficient of variation of this method was less than 5% and the average recovery for beta-lactam was 96.75%. The method is simple and rapid.

Complex behaviours of AB model describing idiotypic network.

A simple chemical model of the idiotypic network of immune systems, namely the AB model, has been developed by De Boer et al. The complexity of the system, such as the steady states, periodic oscillations and chaotic motions, has been examined by the authors mentioned above. In the present paper, the periodic motions and chaotic behaviours exhibited by the system are intuitively described. To clarify in which parameter domains concerned the system exhibits periodic oscillations and in which parameter domains the system demonstrates chaotic behaviours the Lyapounov exponent is explored. To characterize the strangeness of the attractors, the fractal dimension problem is worked out.

A cellular automaton model of cancerous growth.

A cellular automaton model describing immune system surveillance against cancer is furnished. In formulating the model, we have taken into account the microscopic mechanisms of cancerous growth, such as the proliferation of cancer cells, the cytotoxic behaviors of the immune system, the mechanical pressure inside the tumor and so forth. The model may describe the Gompertz growth of a cancer. The results are in agreement with experimental observations. The influences of the proliferation rate of cancer cells, the cytotoxic rate and other relevant factors affecting the Gompertz growth are studied.

[The effect of depolymerization of cytoplasmic microtubules on initiation of DNA synthesis by growth factors in cells].

PPP (platelet-poor plasma) alone can not stimulate DNA synthesis in Go C3H/10T1/2 cells.50 ng/ml of EGF promoted partial Go cells to enter S phase. However, there was an apparent synergic effect of simultaneous treatment with 50 ng/ml EGF and 5%PPP, their synergic effect to stimulate DNA synthesis in Go cells was the same as 10% calf serum. Taxol can resist the depolymerization of microtubules. After treatment with taxol (10 mumol/L), the progression from Go to S phase in C 3 H 10 T 1/2 cells was inhibited. This inhibition was especially exhibited at early stage of transition from Go to S phase. The result indicated that Go cells can not enter S phase without the depolymerization of microtubules. It showed that DNA synthesis was stimulated by the simultaneous treatment with colcemid (0.1 microgram/ml) and growth factors (50 ng/ml EGF + 5% PPP or 10% Calf serum). But without the stimulation of growth factors, the unique effect of depolymerization of microtubules can not stimulate DNA synthesis. The results present evidence indicating that the depolymerization of microtubules has the potency to elevate DNA synthesis in Go cells stimulated by growth factors. This potency was also appeared at early stage of progression from Go to S phase. We suggest that the depolymerization of cytoplasmic microtubules and synergic effect of growth factors are involved in account for the transition from Go to S phase in C 3 H 10 T 1/2 cells.

[The effect of db-cAMP on the gene expression of calmodulin and cytoskeleton in the transformed cells].

We have demonstrated that the distribution of microtubules (MT), microfilaments (MF) and fibronectin (FN) were diminished, while the gene expression of the calmodulin and c-fos enhanced in the transformed C3 H10 T1/2 cells. After treatment with 1 mM db-cAMP for 1 hr. and 2 hrs., there was an early and rapidly reduced in gene expression of calmodulin and c-fos respectively. After db-cAMP treatment for 4-5 days, the number of Capping cells of ConA binding decreased significantly and the cell surface microvilli decreased also. The growth of treated cells was inhibited markedly. By using 4F1 cDNA probe, which is preferentially expressed in G1 phase, we have found that the db-cAMP treated cells were accumulated at G1 phase. Of particular interest is the fact that the distribution of microtubules, microfilaments and fibronectin were recovered after treatment with 1 mM db-cAMP for 6 days. It is suggested that the inhibition of proliferation, alteration of phenotype and recovery of cytoskeleton in transformed cells after treatment with db-cAMP are related to the inhibition of gene expression of calmodulin.