Free-Standing Carbon Nanotube Embroidered Graphene Film Electrode Array for Stable Neural Interfacing.

Implantable neural probes that are mechanically flexible yet robust are attractive candidates for achieving stable neural interfacing in the brain. Current flexible neural probes consist mainly of metal thin-film electrodes integrated on micrometer-thick polymer substrates, making it challenging to achieve electrode-tissue interfacing on the cellular scale. Here, we describe implantable neural probes that consist of robust carbon nanotube network embroidered graphene (CeG) films as free-standing recording microelectrodes. Our CeG film microelectrode arrays (CeG_MEAs) are ultraflexible yet mechanically robust, thus enabling cellular-scale electrode-tissue interfacing. Chronically implanted CeG_MEAs can stably track the activities of the same population of neurons over two months. Our results highlight the potential of ultraflexible and free-standing carbon nanofilms for stable neural interfacing in the brain.

Ultraflexible Neural Probes for Multidirectional Neuronal Activity Recordings over Large Spatial and Temporal Scales.

The widespread dissemination of ultraflexible neural probes depends on the development of advanced materials and implementation strategies that can allow reliable implantation of ultraflexible neural probes into targeted brain regions, especially deep and difficult-to-access brain regions. Here, we report ultraflexible and multidirectional probes that are encapsulated in a biocompatible polymer alloy with controllable dissolution kinetics. Our probes can be reliably implanted into targeted brain regions over large spatial scales, including deep hindbrain regions that are anatomically difficult-to-access in vivo. Chronically implanted probes can enable long-term, multidirectional recordings from several hundreds of neurons across distributed brain regions. In particular, our results show that 87.0% of chronically recorded neurons in the hindbrain are interneurons, whereas only 41.9% of chronically recorded neurons in the cortex are interneurons. These results demonstrate that our ultraflexible neural probes are a promising tool for large-scale, long-term neural circuit dissection in the brain.

US Shear-Wave Elastography Dispersion for Characterization of Chronic Liver Disease.

Background Little is known about the benefits of the use of dispersion slope (DS) as a viscosity-related parameter derived from two-dimensional (2D) shear-wave elastography (SWE) in the stratification of hepatic pathologic stages. Purpose To evaluate whether DS as an additional parameter can improve the diagnostic performance in detecting liver necroinflammation, fibrosis, and steatosis. Materials and Methods In this prospective study, consecutive participants with chronic liver disease who underwent liver biopsy and 2D SWE were recruited between July 2019 and September 2020. DS and liver stiffness (LS) measurements were obtained with use of a 2D SWE system immediately before biopsy. The biopsy specimens were assessed to obtain the scores of fibrosis, necroinflammation, and steatosis. Differences in the area under the receiver operating characteristic curve (AUC) were used to compare the diagnostic performance of DS, LS, and a combination of DS and LS. Results There were 159 participants evaluated (among them, 79 participants with chronic hepatitis B and 11 participants with nonalcoholic fatty liver disease). The distributions of DS values among various necroinflammatory activities (P = .02) and fibrosis stages (P < .001) were different. Moreover, DS was only associated with fibrosis after subgroup analysis based on the fibrosis stages and necroinflammatory activities (P < .001). The AUCs of DS in detecting clinically significant fibrosis (fibrosis stage ≥F2), cirrhosis (fibrosis stage of F4), and moderate to severe necroinflammatory activity (necroinflammatory activity ≥A2) were 0.72 (95% CI: 0.64, 0.79), 0.71 (95% CI: 0.63, 0.78), and 0.64 (95% CI: 0.55, 0.71), respectively. The differences of AUCs were not apparent for the DS and LS combination model after excluding DS (fibrosis stage ≥F2: 0.00 [95% CI: 0.00, 0.01], fibrosis stage of F4: -0.01 [95% CI: -0.02, 0.00], and necroinflammatory activity ≥A2: 0.00 [95% CI: 0.00, 0.01]). Conclusion The addition of dispersion slope derived from two-dimensional shear-wave elastography did not improve the diagnostic performance in detecting liver fibrosis, necroinflammation, or steatosis in patients with primarily viral hepatitis. ClinicalTrials.gov registration no.: NCT03777293 © RSNA, 2022 Online supplemental material is available for this article.

Comparison between spleen and liver stiffness measurements by sound touch elastography for diagnosing cirrhosis at different aminotransferase levels: a prospective multicenter study.

OBJECTIVES: To compare the performance of spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by sound touch elastography (STE) for the diagnosis of cirrhosis at different alanine aminotransferase (ALT) levels, and to compare the applicability and repeatability of SSM with LSM performed by STE, a new two-dimensional shear wave elastography technology. METHODS: This prospective multicenter study included 25 centers and recruited chronic hepatitis B (CHB) patients with liver biopsy between May 2018 and November 2019. All patients underwent LSM and SSM by STE. Success and reliability rates were calculated and compared. Intra-observer agreement was assessed using intraclass correlation coefficients (ICCs). Differences between areas under the receiver operating characteristic curves (AUCs) of LSMs and SSMs at different ALT levels were compared using the Delong test. RESULTS: Among 603 CHB patients, the success and reliability rates of SSM were 94.53% (570/603) and 85.74% (517/603), respectively, which were similar to those of LSM (p > 0.05), respectively. The ICC for intra-observer agreements of SSM was 0.964 (p < 0.001). In the total cohort, ALT ≤ 2 × upper limit of normal (ULN) group, and A0-1 group, the AUCs of SSMs were significantly lower than those of LSMs for the diagnosis of cirrhosis (p < 0.001). In the ALT > 2 × ULN group and A2-3 group, the AUC of SSM improved and was not significantly different from that of LSM (p = 0.342, p = 0.510, respectively). CONCLUSIONS: SSM by STE achieved applicability and repeatability equivalent to those of LSM. SSM might be a good substitute to LSM in patients with high ALT levels. KEY POINTS: • Spleen stiffness measurement performed by sound touch elastography was proven to have similar applicability and repeatability to liver stiffness measurement in this prospective multicenter study. • Spleen stiffness measurement demonstrated a poorer diagnostic performance for cirrhosis compared with liver stiffness measurement in the total cohort and low ALT level group, yet it showed a similar diagnostic performance to liver stiffness measurement in patients with high ALT levels.

Usefulness of New Shear Wave Elastography Technique for Noninvasive Assessment of Liver Fibrosis in Patients with Chronic Hepatitis B: A Prospective Multicenter Study.

PURPOSE: To explore the usefulness of liver stiffness measurements (LSMs) by sound touch elastography (STE) and sound touch quantification (STQ) in chronic hepatitis B (CHB) patients for staging fibrosis. METHODS: This prospective multicenter study recruited normal volunteers and CHB patients between May 2018 and October 2019. The volunteers underwent LSM by STE and supersonic shear imaging (SSI) or by STQ and acoustic radiation force impulse imaging (ARFI). CHB patients underwent liver biopsy and LSM by both STE/STQ. The areas under the receiver operating characteristic curves (AUCs) for staging fibrosis were calculated. RESULTS: Overall, 97 volunteers and 524 CHB patients were finally eligible for the study. The successful STE and STQ measurement rates were both 100 % in volunteers and 99.4 % in CHB patients. The intraclass correlation coefficients (ICCs) for the intra-observer stability of STE and STQ (0.94; 0.90) were similar to those of SSI and ARFI (0.95; 0.87), respectively. STE and STQ showed better accuracy than the aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) (AUC: 0.87 vs 0.86 vs 0.73 vs 0.77) in staging cirrhosis. However, both STE and STQ were not superior to APRI and FIB-4 in staging significant fibrosis (AUC: 0.76 vs 0.73 vs 0.70 vs 0.71, all P-values > 0.05). CONCLUSION: STE and STQ are convenient techniques with a reliable LSM value. They have a similar diagnostic performance and are superior to serum biomarkers in staging cirrhosis in CHB patients.

Liver Stiffness Measured with Two-dimensional Shear-Wave Elastography Is Predictive of Liver-related Events in Patients with Chronic Liver Disease Due to Hepatis B Viral Infection.

Background Liver stiffness measurement has been proposed as a noninvasive marker for predicting liver-related complications of cirrhosis. Purpose To evaluate the predictive value of liver stiffness measurement by using two-dimensional (2D) shear-wave elastography (SWE) for liver-related events among patients with chronic hepatitis B. Materials and Methods This retrospective study recruited consecutive patients with chronic hepatitis B who were referred for liver biopsy between May 2011 and May 2015. All patients underwent 2D SWE before biopsy, and a subset of patients underwent transient elastography. Patients were followed up for 4 years through the electronic medical records or telephone interviews. Univariable and multivariable logistic regression analyses were used to determine prognostic factors. Accuracy of prognostic parameters was evaluated by using the area under the receiver operating characteristic curve (AUC). Results Among 430 patients (mean age, 38 years; range, 18-67 years) including 328 men and 102 women, 29 patients developed liver-related events. Multivariable analysis demonstrated that liver stiffness measured with 2D SWE, spleen longitudinal diameter at US, age, and albumin level were predictive factors of liver-related events. The AUC of the multivariable model was higher (0.89; 95% confidence interval [CI]: 0.86, 0.92) but not significantly different from that of 2D SWE (0.86; 95% CI: 0.82, 0.89; P = .23) and was significantly higher than that of the fibrosis stage (0.72; 95% CI: 0.68, 0.76; P < .001), the aspartate aminotransferase-to-platelet ratio index (0.80; 95% CI: 0.76, 0.84; P < .001), and the fibrosis-4 index (0.84; 95% CI: 0.80, 0.87; P = .02). In a subset of patients with available transient elastography (n = 188), the multivariable model, 2D SWE, and transient elastography showed comparable performance (AUC: 0.91 vs 0.86 vs 0.88, respectively). When inflammatory activity was considered, the multivariable model was highly accurate in patients with low-grade inflammation and normal levels of alanine aminotransferase (AUC: 0.97 and 0.94, respectively). Conclusion The multivariable model and two-dimensional shear-wave elastography are more accurate in predicting liver-related events than are the fibrosis stage and serum markers of liver fibrosis tests. © RSNA, 2020 Online supplemental material is available for this article.

Magnetic Actuation of Flexible Microelectrode Arrays for Neural Activity Recordings.

Implantable microelectrodes that can be remotely actuated via external fields are promising tools to interface with biological systems at a high degree of precision. Here, we report the development of flexible magnetic microelectrodes (FMµEs) that can be remotely actuated by magnetic fields. The FMµEs consist of flexible microelectrodes integrated with dielectrically encapsulated FeNi (iron-nickel) alloy microactuators. Both magnetic torque- and force-driven actuation of the FMµEs have been demonstrated. Nanoplatinum-coated FMµEs have been applied for in vivo recordings of neural activities from peripheral nerves and cerebral cortex of mice. Moreover, owing to their ultrasmall sizes and mechanical compliance with neural tissues, chronically implanted FMµEs elicited greatly reduced neuronal cell loss in mouse brain compared to conventional stiff probes. The FMµEs open up a variety of new opportunities for electrically interfacing with biological systems in a controlled and minimally invasive manner.

Flexible Micropillar Electrode Arrays for In Vivo Neural Activity Recordings.

Flexible electronics that can form tight interfaces with neural tissues hold great promise for improving the diagnosis and treatment of neurological disorders and advancing brain/machine interfaces. Here, the facile fabrication of a novel flexible micropillar electrode array (µPEA) is described based on a biotemplate method. The flexible and compliant µPEA can readily integrate with the soft surface of a rat cerebral cortex. Moreover, the recording sites of the µPEA consist of protruding micropillars with nanoscale surface roughness that ensure tight interfacing and efficient electrical coupling with the nervous system. As a result, the flexible µPEA allows for in vivo multichannel recordings of epileptiform activity with a high signal-to-noise ratio of 252 ± 35. The ease of preparation, high flexibility, and biocompatibility make the µPEA an attractive tool for in vivo spatiotemporal mapping of neural activity.

Genomic analyses reveal mutational signatures and frequently altered genes in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide and the fourth most lethal cancer in China. However, although genomic studies have identified some mutations associated with ESCC, we know little of the mutational processes responsible. To identify genome-wide mutational signatures, we performed either whole-genome sequencing (WGS) or whole-exome sequencing (WES) on 104 ESCC individuals and combined our data with those of 88 previously reported samples. An APOBEC-mediated mutational signature in 47% of 192 tumors suggests that APOBEC-catalyzed deamination provides a source of DNA damage in ESCC. Moreover, PIK3CA hotspot mutations (c.1624G>A [p.Glu542Lys] and c.1633G>A [p.Glu545Lys]) were enriched in APOBEC-signature tumors, and no smoking-associated signature was observed in ESCC. In the samples analyzed by WGS, we identified focal (<100 kb) amplifications of CBX4 and CBX8. In our combined cohort, we identified frequent inactivating mutations in AJUBA, ZNF750, and PTCH1 and the chromatin-remodeling genes CREBBP and BAP1, in addition to known mutations. Functional analyses suggest roles for several genes (CBX4, CBX8, AJUBA, and ZNF750) in ESCC. Notably, high activity of hedgehog signaling and the PI3K pathway in approximately 60% of 104 ESCC tumors indicates that therapies targeting these pathways might be particularly promising strategies for ESCC. Collectively, our data provide comprehensive insights into the mutational signatures of ESCC and identify markers for early diagnosis and potential therapeutic targets.

AKT Hyperactivation and the Potential of AKT-Targeted Therapy in Diffuse Large B-Cell Lymphoma.

AKT signaling is important for proliferation and survival of tumor cells. The clinical significance of AKT activation in diffuse large B-cell lymphoma (DLBCL) is not well analyzed. Here, we assessed expression of phosphorylated AKT (p-AKT) in 522 DLBCL patients. We found that high levels of p-AKT nuclear expression, observed in 24.3% of the study cohort, were associated with significantly worse progression-free survival and Myc and Bcl-2 overexpression. However, multivariate analysis indicated that AKT hyperactivation was not an independent factor. miRNA profiling analysis demonstrated that 63 miRNAs directly or indirectly related to the phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin pathway were differentially expressed between DLBCLs with high and low p-AKT nuclear expression. We further targeted AKT signaling using a highly selective AKT inhibitor MK-2206 in 26 representative DLBCL cell lines and delineated signaling alterations using a reverse-phase protein array. MK-2206 treatment inhibited lymphoma cell viability, and MK-2206 sensitivity correlated with AKT activation status in DLBCL cells. On MK-2206 treatment, p-AKT levels and downstream targets of AKT signaling were significantly decreased, likely because of the decreased feedback repression; Rictor and phosphatidylinositol 3-kinase expression and other compensatory pathways were also induced. This study demonstrates the clinical and therapeutic implications of AKT hyperactivation in DLBCL and suggests that AKT inhibitors need to be combined with other targeted agents for DLBCL to achieve optimal clinical efficacy.

Hepatitis C virus positive diffuse large B-cell lymphomas have distinct molecular features and lack BCL2 translocations.

BACKGROUND: The clinical presentation of patients with hepatitis C virus (HCV)-positive diffuse large B-cell lymphoma (DLBCL) is different from their HCV-negative counterparts, but the underlying molecular and pathological characteristics are largely under investigated. The virus has a role in lymphomagenesis, as witnessed by the curative potential of antiviral therapy in HCV-related low-grade B-cell lymphomas. METHODS: We performed a case-control study including 44 HCV-positive cases of de novo DLBCL, comparing them with 132 HCV-negative patients as controls (ratio 3 to 1). Cases and controls were matched for age, lactate dehydrogenase level and international prognostic index at presentation. Patients were studied by gene expression profiling for cell-of-origin determination and to perform differential expression analysis between groups, fluorescence in-situ hybridisation and immunohistochemistry for MYC, BCL2 and BCL6, TP53 mutations, and diagnostic specimens reviewed to exclude transformation from low-grade lymphoma. RESULTS: Compared to the HCV-negative controls, patients with HCV-positive de novo DLBCL had differential expression of genes that regulate innate immune response and modulate apoptotic pathways, have higher proliferative index, and lack BCL2 translocations. CONCLUSIONS: HCV-positive DLBCL have distinct molecular and pathological features compared to the HCV-negative counterparts.

Comparison of Two Types of Overoxidized PEDOT Films and Their Application in Sensor Fabrication.

Poly(3,4-ethylenedioxythiophene) (PEDOT) films were prepared by electro-oxidation on Au microelectrodes in an aqueous solution. Electrolyte solutions and polymerization parameters were optimized prior to overoxidation. The effect of overoxidation time has been optimized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), which results in the film overoxidized for 45 s at 1.35 V presenting a strong adsorption. The other one-step overoxidation film prepared by direct CV ranging from -0.6 V to 1.35 V was polymerized for comparison. Scanning electron microscope (SEM) analysis and Fourier transform infrared (FTIR) spectroscopy were used for monitoring morphological changes and the evolution of functional groups. Both of them indicate increased abundant oxygen functional groups and roughness, yet the products exhibit dendritic morphology and piles of spherical protrusions, respectively. Moreover, double-step overoxidized film showed better electrochemical performance toward lead ion sensing. These characterizations highlight some novel properties that may be beneficial for specific sensing applications.

A Palladium-Tin Modified Microband Electrode Array for Nitrate Determination.

A microband electrode array modified with palladium-tin bimetallic composite has been developed for nitrate determination. The microband electrode array was fabricated by Micro Electro-Mechanical System (MEMS) technique. Palladium and tin were electrodeposited successively on the electrode, forming a double-layer structure. The effect of the Pd-Sn composite was investigated and its enhancement of catalytic activity and lifetime was revealed. The Pd-Sn modified electrode showed good linearity (R² = 0.998) from 1 mg/L to 20 mg/L for nitrate determination with a sensitivity of 398 µA/(mg∙L(-1)∙cm²). The electrode exhibited a satisfying analytical performance after 60 days of storage, indicating a long lifetime. Good repeatability was also displayed by the Pd-Sn modified electrodes. The results provided an option for nitrate determination in water.

[Expression of CD68, cyclin D1 and rearrangement of bcl-6 gene are adverse prognostic factors in diffuse large B-cell lymphoma].

OBJECTIVE: To study expression of CD68, cyclin D1 protein and rearrangement of bcl-6 gene impact on the prognosis of diffuse large B-cell lymphoma (DLBCL). METHODS: Gets paraffin samples of the 105 cases DLBCL with the detailed follow-up information, and were studied by using immunohistochemical EnVision method for CD3, CD10, CD20, CD68, cyclin D1, bcl-6, MUM 1, SOX-11 immunolabeling. The DLBCL were classified into germinal center B cell-like (GCB) subtypes and non-germinal center B cell-like (non-GCB) subtypes according to Hans'algorithm. Application of fluorescence in situ hybridization (FISH) technique to detect the bcl-6 gene rearrangement. The relationship between CD68, cyclin D1 protein, the bcl-6 gene and the curative effect of chemotherapy and survival was analyzed using statistical software. Respectively by GCB type, non-GCB type immune phenotype and CHOP, R-CHOP chemotherapy group, compare the curative effects. RESULTS: 105 patients had GCB 19 cases (18.1%), non-GCB 86 cases (81.9%), CD68 expression was 18 cases (17.1%), cyclin D1 high expression 36 cases (34.3%), bcl-6 gene rearrangement in 21 cases (21.9%), there is no correlation among the three (P > 0.05). One-way analysis of variance showed that age ≤ 60 years, clinical stage I-II, IPI score 0 to 2 points, LDH (U/L) < 245 IU/L,GCB subtypes, R-CHOP therapy, the prognosis of patients with better (P < 0.05), But gender, primary site no correlation with prognosis (P > 0.05). CD68, cyclin D1 high expression, bcl-6 rearrangement had poor prognosis (P < 0.05). Stratification analysis results show GCB-type or non-GCB type with high expression of CD68 contrast alloimmune phenotype groups had a poor prognosis, non-GCB type with high expression of cyclin D1 and rearrangement of bcl-6 gene had a poor prognosis (P < 0.001, P = 0.02). Treatment scheme of layered display, the CHOP treatment, significantly correlated with overall survival with high expression of CD68, cyclin D1 (P < 0.05), the R-CHOP treatment, there was no statistically significant difference between CD68, cyclin D1 high expression and overall survival (P = 0.428 and 0.168). Multivariate COX model analysis showed that high expression of CD68 (P = 0.026), high expression of cyclin D1 (P = 0.003) and high levels of LDH (P = 0.005) were adverse prognostic factors independent. CONCLUSIONS: high expression of CD68, cyclin D1 and rearrangement of bcl-6 gene suggests poor prognosis, CD68, cyclin D1 protein and bcl-6 gene can be used as a prognostic indicator in patients with DLBCL.

Transcript suppression of TaGW2 increased grain width and weight in bread wheat.

Bread wheat (Triticum aestivum L.) is a major staple crop in the world. Grain weight is a major factor of grain yield in wheat, and the identification of candidate genes associated with grain weight is very important for high-yield breeding of wheat. TaGW2 is an orthologous gene of rice OsGW2 that negatively regulates the grain width and weight in rice. There are three TaGW2 homoeologs in bread wheat, TaGW2A, TaGW2B, and TaGW2D. In this study, a specific TaGW2-RNA interference (RNAi) cassette was constructed and transformed into a Chinese bread wheat variety 'Shi 4185' with small grain. The transcript levels of TaGW2A, TaGW2B, and TaGW2D were simultaneously downregulated in TaGW2-RNAi transgenic wheat lines. Compared with the controls, TaGW2-underexpressing transgenic lines displayed significantly increases in the grain width and weight, suggesting that TaGW2 negatively regulated the grain width and weight in bread wheat. Further transcript analysis showed that in different bread wheat accessions, the transcript abundance of TaGW2A was negatively associated with the grain width.

Modification of graphene on ultramicroelectrode array and its application in detection of dissolved oxygen.

This paper investigated two different modification methods of graphene (GN) on ultramicroelectrode array (UMEA) and applied the GN modified UMEA for the determination of dissolved oxygen (DO). The UMEAs were fabricated by Micro Electro-Mechanical System (MEMS) technique and the radius of each ultramicroelectrode is 10 µm. GN-NH2 and GN-COOH were modified on UMEA by using self-assembling method. Compared with GN-NH2 modified UMEA, the GN-COOH modified UMEA showed better electrochemical reduction to DO, owing to better dispersing and more active sites. The GN-COOH on UMEA was electroreduced to reduced GN-COOH (rGN-COOH) to increase the conductivity and the catalysis performance. Finally, the palladium nanoparticles/rGN-COOH composite was incorporated into DO microsensor for the detection of DO.

[Comparative analysis of real-time quantitative PCR-Sanger sequencing method and TaqMan probe method for detection of KRAS/BRAF mutation in colorectal carcinomas].

OBJECTIVE: To compare the application values of real-time quantitative PCR-Sanger sequencing and TaqMan probe method in the detection of KRAS and BRAF mutations, and to correlate KRAS/BRAF mutations with the clinicopathological characteristics in colorectal carcinomas. METHODS: Genomic DNA of the tumor cells was extracted from formalin fixed paraffin embedded (FFPE) tissue samples of 344 colorectal carcinomas by microdissection. Real-time quantitative PCR-Sanger sequencing and TaqMan probe method were performed to detect the KRAS/BRAF mutations. The frequency and types of KRAS/BRAF mutations, clinicopathological characteristics and survival time were analyzed. RESULTS: KRAS mutations were detected in 39.8% (137/344) and 38.7% (133/344) of 344 colorectal carcinomas by using real-time quantitative PCR-Sanger sequencing and TaqMan probe method, respectively. BRAF mutation was detected in 4.7% (16/344) and 4.1% (14/344), respectively. There was no significant correlation between the two methods. The frequency of the KRAS mutation in female was higher than that in male (P < 0.05). The frequency of the BRAF mutation in colon was higher than that in rectum. The frequency of the BRAF mutation in stage III-IV cases was higher than that in stageI-II cases. The frequency of the BRAF mutation in signet ring cell carcinoma was higher than that in mucinous carcinoma and nonspecific adenocarcinoma had the lowest mutation rate. The frequency of the BRAF mutation in grade III cases was higher than that in grade II cases (P < 0.05). The overall concordance for the two methods of KRAS/BRAF mutation detection was 98.8% (kappa = 0.976). There was statistic significance between BRAF and KRAS mutations for the survival time of colorectal carcinomas (P = 0.039). There were no statistic significance between BRAF mutation type and BRAF/KRAS wild type (P = 0.058). CONCLUSIONS: (1) Compared with real-time quantitative PCR-Sanger sequencing, TaqMan probe method is better with regard to handling time, efficiency, repeatability, cost and equipment. (2) The frequency of the KRAS mutation is correlated with gender. BRAF mutation is correlated with primary tumor site, TNM stage, histological types and histological grades.(3) BRAF gene mutation is an independent prognostic marker for colorectal carcinomas.