Cesium Amide-Catalyzed Selective Deuteration of Benzylic C-H Bonds with D2 and Application for Tritiation of Pharmaceuticals.

Hydrogen isotope exchange (HIE) represents one of the most attractive labeling methods to synthesize deuterium- and tritium-labeled compounds. Catalytic HIE methods that enable site-selective C-H bond activation and exchange labeling with gaseous isotopes D2 and T2 are of vital importance, in particular for high-specific-activity tritiation of pharmaceuticals. As part of our interest in exploring s-block metals for catalytic transformations, we found CsN(SiMe3 )2 to be an efficient catalyst for selective HIE of benzylic C-H bonds with D2 gas. The reaction proceeds through a kinetic deprotonative equilibrium that establishes an exchange pathway between C-H bonds and D2 gas. By virtue of multiple C-H bonds activation and high activity (isotope enrichment up to 99 %), the simple cesium amide catalyst provided a very powerful and practically convenient labeling protocol for synthesis of highly deuterated compounds and high-specific-activity tritiation of pharmaceuticals.

Relationship between mismatch repair protein, RAS, BRAF, PIK3CA gene expression and clinicopathological characteristics in elderly colorectal cancer patients.

BACKGROUND: Colorectal cancer (CRC) is common in elderly patients. Mismatch repair (MMR) protein deletion is one of the causes of CRC. The RAS (KRAS/NRAS), BRAF, and PIK3CA genes are important gene targets in CRC treatment and are closely related to the prognosis and survival of patients. However, little is known regarding the relationship between the expression of MMR, RAS, BRAF, PIK3CA and the clinicopathological features in CRC patients. AIM: To analyze the relationship between the expression of MMR, RAS, BRAF, PIK3CA and the clinicopathological features in CRC. METHODS: A total of 327 elderly patients with CRC were enrolled, and immuno-histochemistry was used to detect the MMR protein. Real-time quantitative polymerase chain reaction was used to detect the RAS (KRAS/NRAS), BRAF, and PIK3CA genes. The clinicopathological data of the patients were recorded and analyzed by SPSS 19.0 statistical software. RESULTS: In 327 elderly patients with CRC, the rate of MMR protein loss was 9.79% (32/327), and the deletion rate of four MMR proteins (MSH2, MSH6, MLH1, PMS2) was 1.83% (6/327), 3.06% (10/327), 7.65% (25/327), and 7.65% (25/327), respectively. There were no significant differences between MMR protein deletion and sex, pathological type, tumor morphology, differentiation degree or lymph node metastasis (P > 0.05), but there was a significant difference between MMR protein deletion and tumor diameter and tumor location (P = 0.048/P = 0.000). The mutation rates of the KRAS, NRAS, BRAF and PIK3CA genes in elderly CRC patients were 44.95% (147/327), 2.45% (8/327), 3.36% (11/327) and 2.75% (9/327), respectively; the KRAS gene mutation was closely related to tumor morphology (P = 0.002) but not to other clinicopathological features (P > 0.05), and there were no significant differences between NRAS gene mutation and clinicopathological features (P > 0.05). The BRAF gene mutation showed a significant difference in pathological type, tumor location, differentiation degree and lymph node metastasis (P < 0.05), but was not correlated with sex, tumor size and tumor morphology (P > 0.05). The PIK3CA gene mutation showed no significant differences in the above clinicopathological characteristics (P > 0.05). Significant differences were observed between MMR protein deletion and KRAS, BRAF, and PIK3CA gene mutations in elderly CRC patients (P = 0.044, P = 0.000, P = 0.003, respectively), but there was no significant difference between MMR protein deletion and NRAS mutation (P > 0.05). CONCLUSION: In elderly CRC patients, the tumor is mainly located in the right colon, and the deletion rate of MMR protein is higher when the tumor diameter is greater than or equal to 5 cm; the deletion rate of MLH1 and PMS2 is more common; the mutation rate of KRAS gene is higher than that of the NRAS, BRAF and PIK3CA genes, the BRAF gene mutation has different degrees of correlation with clinicopathological characteristics; when the MMR protein is deleted, the BRAF and PIK3CA gene mutations are often present, and the KRAS gene mutation rate is low.

Robot-assisted gallbladder-preserving hepatectomy for treating S5 hepatoblastoma in a child: A case report and review of the literature.

BACKGROUND: Hepatoblastoma (HB) is the most common hepatic malignant tumour in children, accounting for approximately 50%-60% of primary hepatic malignant tumours in children, mostly in children under 3 years old. In Western countries, the incidence of hepatoblastoma is approximately 1-2/100000. Da Vinci surgical system is fast becoming a key instrument in microinvasive surgery. The past decade has seen the rapid development of robot-assisted laparoscopy, which expends many fields including the liver surgery. This paper discusses the significance and feasibility of robot-assisted gallbladder-preserving hepatectomy for treating S5 hepatoblastoma in children. The aim of this essay is to compare the safety and effectiveness of robotic surgery with conventional laparoscopic surgery, and explore the meaning of preservation of the gallbladder by sharing this case. CASE SUMMARY: A 3-year-old child with a liver mass in the 5th segment was treated using the Da Vinci surgical system, and the gallbladder was retained. The child was admitted to the hospital for 20 d for the discovery of the right hepatic lobe mass. Ultrasonography revealed a low echo mass, 46 mm × 26 mm × 58 mm in size, indicating hepatoblastoma in the right lobe, and enhanced computed tomography showed continuous enhancement of iso-low-density lesions with different sizes and nodules and unclear boundaries, without the dilation of the intrahepatic bile duct, no enlargement of the gallbladder, and uniform thickness of the wall. The diagnosis was "liver mass, hepatoblastoma". It was decided to perform S5 liver tumour resection. During surgery, the tumour and gallbladder were isolated first, and the gallbladder could be completely separated from the tumour surface without obvious infiltration; therefore, the gallbladder was preserved. The cutting line was marked with an electric hook. The hepatic duodenal ligament was blocked with a urethral catheter using the Pringle method, and the tumour and part of the normal liver tissue were completely resected with an ultrasound knife along the incision. The hepatic portal interdiction time was approximately 25 min. An abdominal drainage tube was inserted. The auxiliary hole was connected to the lens, and the specimen was removed. The patient's status was uneventful, and the operation time was 166 min. The robotic time was 115 min, and the bleeding amount was approximately 200 mL. In total, 300 mL of red blood cell suspension and 200 mL of plasma were injected. No serious complications occurred. Pathological findings confirmed fetal hepatoblastoma and R0 resection. A gallbladder contraction test was performed two weeks after surgery. CONCLUSION: Robot-assisted S5 hepatectomy with gallbladder preservation is safe and feasible for specific patients.