RIPK1 gene polymorphism as a prognostic marker for survival in patients with colorectal cancer

e15078

Background: Since apoptosis plays a key role in cancer progression, we hypothesized that single nucleotide polymorphisms (SNPs) of apoptosis-related gene can affect survival after curative resection in patients with colorectal cancer. Patients and Methods: Three hundred and ninety seven patients with colorectal cancer who underwent surgery with curative intent were enrolled in the present study. The genomic DNA was extracted from fresh colorectal mucosal tissue, and the 19 SNPs of 15 apoptosis-related genes (CASP3, CASP6–10, FAS, FAS ligand [FASLG], TNSFR1A, TNSFR10B, RIPK1, BCL2, BCL2 ligand [BCL2L], TP53, and PTGS2) were determined using a PCR-RFLP assay. Results: The median age of the patients was 63 years (range, 21–85), and 218 (54.9%) patients had colon cancer and 179 (45.1%) patients rectal cancer. Pathologic stages after surgery were as follows: stage 0/I (n=86, 21.7%), stage II (n=146, 36.8%), stage III (n=145, 36.5%), and stage IV (n=20, 5.0%). Multivariate survival analysis including pathologic stage, differentiation, age, and CEA level showed that relapse-free survival for the patients with the GA+AA genotype of RIPK1 (Receptor interacting serine/threonine kinase 1) +83G>A (rs2272990) was worse than for the patients with the GG genotype (hazard ratio [HR]=1.66, 95% confidence interval [CI]=1.03–2.68, p=0.038). However, no associations were observed between the polymorphisms and overall survival (OS) in a multivariate analysis. Conclusions: RIPK1 gene polymorphism can be considered as a possible prognostic marker for survival after curative resection in patient with colorectal cancer.

No significant financial relationships to disclose.

Ultrasonographic visualization of balloon placement for uterine tamponade in massive primary postpartum hemorrhage

This case report is the first documentation of ultrasonographic confirmation of positioning of a Sengstaken-Blakemore balloon catheter (SBEC) in the management of massive postpartum hemorrhage. The sonongraphic position, while incorrect according to conventional use of uterine balloon catheters, raises the possibility of an alternative mechanism of action of the balloon: not uterine cavity tamponade but hydrostatic pressure directly around the uterine arteries, a mechanism akin to mechanical uterine artery embolization or ligation. If this hypothesis is correct, it not only elucidates how balloon tamponade works but also challenges current thinking on how postpartum hemorrhage should be managed effectively. Future studies are required to corroborate this hypothesis and we believe that sonographic confirmation of balloon catheter location should be an integral part of uterine balloon tamponade in women with massive primary postpartum hemorrhage.

Fabrication of silicon dioxide submicron channels without nanolithography for single biomolecule detection

We successfully fabricated nanochannel arrays with silicon dioxide (SiO(2)) surfaces for single biomolecule detection. The SiO(2) nanochannel fabrication is based on the combination of anisotropic etching by potassium hydroxide (KOH) solution, local oxidation of silicon (LOCOS) and plasma etching of silicon. This fabrication technique is easily controllable and is a simple and practical solution for low-cost and high-throughput fabrication of nanofluidic channels. Thus, this technique enables the generation of nanochannels with various nanoscale dimensions without using nanolithography.

Characterization of a dUTPase from the hyperthermophilic archaeon Thermococcus onnurineus NA1 and its application in polymerase chain reaction amplification

Genomic analysis of the hyperthermophilic archaeon Thermococcus onnurineus NA1 (TNA1) revealed the presence of a 471-bp open reading frame with 93% similarity to the dUTPase from Pyrococcus furiosus. The dUTPase-encoding gene was cloned and expressed in Escherichia coli. The purified protein hydrolyzed dUTP at about a 10-fold higher rate than dCTP. The protein behaved as a dimer in gel filtration chromatography, even though it contains five motifs that are conserved in all homotrimeric dUTPases. The dUTPase showed optimum activity at 80 degrees C and pH 8.0, and it was highly thermostable with a half-life (t (1/2)) of 170 min at 95 degrees C. The enzymatic activity of the dUTPase was largely unaffected by variations in MgCl(2), KCl, (NH(4))(2)SO(4), and Triton X-100 concentrations, although it was reduced by bovine serum albumin. Addition of the dUTPase to polymerase chain reactions (PCRs) run with TNA1 DNA polymerase significantly increased product yield, overcoming the inhibitory effect of dUTP. Further, addition of the dUTPase allowed PCR amplification of targets up to 15 kb in length using TNA1 DNA polymerase. This enzyme also improved the PCR efficiency of other archaeal family B type DNA polymerases, including Pfu and KOD.