Combining Hydrodefluorination and Defluorophosphorylation for Chemo- and Stereoselective Synthesis of gem-Fluorophosphine Alkenes.

A chemo-, regio-, and stereoselective reaction of trifluoromethyl enones, phenylsilane, and phosphine oxides through a sequential hydrodefluorination and defluorophosphorylation relay is developed for the synthesis of distinctive gem-fluorophosphine alkenes. This multicomponent reaction occurred under transition-metal-free conditions with good functional group tolerance. Moreover, the preinstalled carbonyl auxiliary is important for tuning the reactivity of ß-trifluoromethyl enones, thereby enabling controllable and selective functionalization of two fluorine atoms in trifluoromethylated enones.

Selective and Controllable Defluorophosphination and Defluorophosphorylation of Trifluoromethylated Enones: An Auxiliary Function of the Carbonyl Group.

The auxiliary function of a carbonyl group in the tunable defluorophosphination and defluorophosphorylation of trifluoromethylated enones with P(O)-containing compounds was demonstrated. Controlled replacement of one or two fluorine atoms in trifluoromethylated enones while maintaining high chemo- and stereoselectivity was achieved under mild conditions, thus enabling diversity-oriented synthesis of skeletally diverse organophosphorus libraries─(Z)-difluoro-1,3-dien-1-yl phosphinates, (1Z,3E)-4-phosphoryl-4-fluoro-buta-1,3-dien-1-yl phosphinates, and (E)-4-phosphoryl-4-fluoro-1,3-but-3-en-1-ones─in good yields with excellent functional group tolerance.

Na2S·9H2O Enabled Defluorodisulfuration and Hydrodefluorination of Perfluorobutyl Tetralones: Synthesis of Trifluoromethyl 1,2-Dithioles.

An unprecedented defluorocyclization of perfluorobutyl tetralones with Na2S·9H2O was developed for the synthesis of trifluoromethyl 1,2-dithioles, which provided chemists novel access to biologically and pharmaceutically relevant organofluorides. Successive C(sp3)-F bond functionalization at the perfluoroalkyl chain is vital for the formation of four C-H/C-S/S-S bonds and a five-membered S-heterocycle assembly. Cheap, weakly toxic, and odorless inorganic sulfide Na2S·9H2O acts as both a disulfurating precursor and a hydrodefluorinating reagent in this tandem multi-bond-interconverting reaction.

Dual Role of (NH4)2CO3 Enables Defluorinative Synthesis of ß-Fluoroalkylated Aminovinyl Ketones.

A modular multicomponent reaction of readily available fluoroalkyl alkenes, amidines, ammonium carbonate, and water was developed for the facile construction of ß-fluoroalkylated aminovinyl ketones, which provided chemists a novel access to value-added organofluorine compounds. The reaction proceeded regio-/stereoselectively under mild conditions and exhibited good functional group tolerance. Cheap, stable, and low-toxic inorganic salt (NH4)2CO3 was first found to act as both a nitrogen source and a carbonyl equivalent in the multi-bond-forming process.

Preparation of uniform prednisolone microcrystals by a controlled microprecipitation method.

Prednisolone (PDL) microcrystals were successfully prepared by a controlled microprecipitation method. The characterization of PDL microcrystals by SEM and PSD indicated that the hexagonal and tetragonal PDL microcrystals with an average particle size of 1.60 and 1.46 microm could be prepared under a stirring speed of 10,000 rpm at 14 and 4 degrees C, respectively. The morphology and the particle size of PDL could be well controlled, from 1.60 to 6.12 microm for hexagonal microcrystals and 1.46 to 3.90 microm for tetragonal ones, by altering the operating parameters such as temperature, stirring speed and stabilizers. The XRD, TGA-DSC, FT-IR and physical stability studies demonstrated that the as-prepared hexagonal and tetragonal PDL microcrystals with the same pseudopolymorphic form were much more stable in water than the commercial micronized PDL with another crystal form. The dissolution tests showed that the hexagonal and tetragonal PDL microcrystals exhibited significantly enhanced dissolution property when compared to commercial micronized PDL.

[Experimental study of preventing postoperative stenosis by modifying artificial esophagus in dogs].

OBJECTIVE: To observe the effect of the modified artificial esophagus on postoperative stenosis in dogs. METHODS: The models of defected esophagus were established in dogs. The double-layered membrane tube (modifying type) was implanted in the test group (n = 10) and the esophageal stent was further inserted when the stenosis occurred. The single pattern tube (original type) was transplanted to the control group (n = 30). The dilation treatment was performed to relieve the postoperative stenosis; alternatively, the esophageal stent was implanted in the unsuccessful dogs. RESULTS: The average artificial esophagus removal time was 19.10 days in the test group, which was significantly lower than 39.07 days in the control group (t = 15.6, P = 0.000). No obstruction after removal was observed in the experimental group. The incidence of postoperative stenosis had no significant difference between these two groups. CONCLUSION: The double-layered membrane tube can make the tube removal safer by shortening the removal time.

Digital design and fabrication of simulation model for measuring orthodontic force.

Three dimensional (3D) forces are the key factors for determining movement of teeth during orthodontic treatment. Designing precise forces and torques on tooth before treatment can result accurate tooth movements, but it is too difficult to realize. In orthodontic biomechanical systems, the periodontal tissues, including bones, teeth, and periodontal ligaments (PDL), are affected by braces, and measuring the forces applied on the teeth by braces should be based on a simulated model composed of these three types of tissues. This study explores the design and fabrication of a simulated oral model for 3D orthodontic force measurements. Based on medical image processing, tissue reconstruction, 3D printing, and PDL simulation and testing, a model for measuring force was designed and fabricated, which can potentially be used for force prediction, design of treatment plans, and precise clinical operation. The experiment illustrated that bi-component silicones with 2:8 ratios had similar mechanical properties to PDL, and with a positioning guide, the teeth were assembled in the mandible sockets accurately, and so a customized oral model for 3D orthodontic force measurement was created.

[Antitumor efficacy of fusion cells from esophageal carcinoma cells and dendritic cells as a vaccine in vitro].

BACKGROUND & OBJECTIVE: Dendritic cells (DCs) are antigen-presenting cells, and DC-based fusion vaccine of DCs with tumor cells can induce specific immune response against tumor cells effectively. This study was to investigate the antitumor immunity efficacy of fusion vaccine of DCs with human esophageal carcinoma EC109 cells in vitro. METHODS: Peripheral blood mononuclear cells (PBMCs) from healthy volunteers were isolated, and cultured with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and interleukin-4 (IL-4) to generate DCs. Fusion cells of DCs with EC109 cells were generated by polyethylene glycol (PEG) protocol. The T-cell proliferation response stimulated by DC/EC109 cells was detected by MTT assay. The killing efficacy of cytotoxic T lymphocytes (CTLs), activated by DC/EC109 cells, on EC109 cells was evaluated by LDH assay in vitro, and compared with the killing efficacy on human gastric carcinoma SGC7901 cells and human breast cancer MCF7 cells. RESULTS: The highest fusion efficiency of DCs with EC109 cells was 22.25%. The stimulating efficacy of DC/EC109 cells on the proliferation of T cells was significantly higher than those of DCs and EC109 cells (P<0.05). DC/EC109 cells induced specific CTLs against EC109 cells, and the killing efficacy of the CTLs was significantly higher for EC109 cells than for SGC7901 cells or MCF7 cells (P<0.05). CONCLUSION: C/EC109 fusion vaccine can induce specific antitumor response against EC109 cells effectively.

[Histological regeneration process of "neo-esophagus"].

BACKGROUND & OBJECTIVE: During the reconstruction process of organs or tissues, different implant materials can lead to different healing results because of different extracellular matrix interfaces and tissue biocompatibilities. This study was to observe the regeneration process of "neo-esophagus"after implanting an artificial esophagus, and investigate its healing mechanism. METHODS: Histopathologic studies on neo-esophagus in 1, 3, 6, 12, and 24 months after implantation were performed using gross-giant specimen technique and special staining methods. The processes of tissue molding and reconstruction, and regeneration of high-level cell organ in "neo-esophagus"were observed. RESULTS: The artificial esophagus temporarily replaced the defective esophagus at the early stage after implantation, and dropped off about 1 month after operation. The epithelization of neo-esophagus induced by host tissue was completed about 3-6 months after operation. The submucous muscle layer, mucous glands, nerve fiber, and capillaries were reconstructed about 12 months after operation. The narrowing of "neo-esophagus" occurred about 3-6 months after operation and was relieved 12 months after operation. CONCLUSIONS: The implanted artificial esophagus made of bio-material can replace the defective esophagus at the early stage, and induce connective tissues, including collagen and fibroblasts, to deposit and cover on it to form neo-esophagus. The neo-esophagus is developed by epithelization and reconstruction of submucous muscle layer, mucous glands, nerve fiber, and capillaries 12 months after operation. The narrowing of "neo-esophagus" is caused by overgrowth and contraction of scars.

[In vitro killing effects of STI571 on esophageal carcinoma cell lines CE-48T and CE-81T].

BACKGROUND & OBJECTIVE: Tyrosine kinase mediates cell proliferation and differentiation, and plays important roles in tumorigenesis and development of esophageal carcinoma. STI571 is a tyrosine kinase inhibitor of platelet-derived growth factor receptor beta (PDGFR-beta) which is overexpressed in esophageal carcinoma. This study was to explore the in vitro killing effects of STI571 on esophageal carcinoma cell lines CE-48T and CE-81T. METHODS: The expression of PDGFR-alpha and PDGFR-beta in CE-48T and CE-81T cells was detected by Western blot. The killing effects of STI571 on CE-48T and CE-81T cells were evaluated by MTT assay. Cell apoptosis was analyzed by flow cytometry with Annexin V/PI labeling. The expression of p-PDGFR-beta was detected by Western blot before and after treatment of STI571. RESULTS: CE-48T cells expressed PDGFR-beta, but did not express PDGFR-alpha; CE-81T cells did not express both PDGFR-alpha and PDGFR-beta. The 50% inhibitory concentration (IC50) of STI571 was significantly lower for CE-48T cells than for CE-81T cells [(8.32+/-1.50) micromol/L vs. (41.02+/-7.64) micromol/L, P=0.002]. When treated with 10 micromol/L STI571 for 12 h, the apoptosis rate of CE-48T cells was (52.43+/-5.30)%, but the apoptosis rate did not increase as the treatment time and concentration increased. After treatment of STI571, the expression of p-PDGFR-beta was inhibited in CE-48T cells, but didn't change in CE-81T cells. CONCLUSIONS: STI-571 could induce the apoptosis of PDGFR-beta-positive esophageal carcinoma CE-48T cells. p-PDGFR-beta might be the target of STI571.

[Expression of Smac in Stage I-II non-small cell lung cancer and its clinical significance].

BACKGROUND & OBJECTIVE: Second mitochondrial activator of caspase (Smac) was recently identified as a new apoptogenic factor that is released from mitochondria. It promotes apoptosis by antagonizing inhibitor of apoptosis proteins, and shows in vitro antitumor effect. However, little is known about its role in non-small cell lung cancer (NSCLC). This study was to investigate the expression of Smac in stage I-II NSCLC, and explore its correlations to clinicopathologic features and prognosis. METHODS: Immunohistochemistry and tissue microarray were used to detect the expression of Smac in 213 specimens of stage I-II NSCLC. Its correlations to clinicopathologic features and prognosis of NSCLC were analyzed. RESULTS: The 5-year survival rate of the patients with stage I NSCLC was 61.9%, and that of the patients with stage II NSCLC was 30.0%. Smac protein was mainly localized in cytoplasm. When the positive cells percentage of 75% was used as a cutoff point, 129 (39.4%) samples showed high Smac expression, and 84 (60.6%) showed low Smac expression. Smac expression was not correlated to sex, age, histological type, blood type and prognosis of the patients, whereas the positive rate of Smac was significantly higher in the patients with lymph node metastasis than in the patients without lymph node metastasis (58.3% vs. 37.0%, P<0.05). CONCLUSION: Smac protein might be correlated to lymph node metastasis of NSCLC.

[Application of endoscopic ultrasonography to preoperative clinical staging of esophageal cancer].

BACKGROUND & OBJECTIVE: Preoperative clinical staging is the key to choose ideal therapy plan for esophageal cancer. Endoscopic ultrasonography (EUS), an accuracy diagnostic technique for TN staging of esophageal cancer, is used commonly in foreign countries, but seldom in China. This study was to evaluate the application of EUS to preoperative clinical staging of esophageal cancer. METHODS: A total of 72 patients were examined preoperatively with EUS, and staged according to UICC (1997) TNM staging system. The EUS findings were compared with surgical pathologic findings. RESULTS: The accuracy rates of T staging and N staging by EUS were 80.6% (58/72) and 88.9% (64/72), respectively. The accuracy rates of T staging were 50.0% (2/4) for T0, 75.0% (3/4) for T1, 70.6% (12/17) for T2, 90.0% (36/40) for T3, and 71.4% (5/7) for T4; those of N staging were 92.3% (36/39) for N0 and 84.8% (28/33) for N1, of which the accuracy rates of diagnosing mediastinum and abdomen lymph node metastases were 90.0% and 64.5%. The staging results by EUS were significantly accordant with those by surgical pathology: T staging, association coefficient = 0.687, P < 0.001; N staging, association coefficient = 0.878, P < 0.001. Twenty-two cases were staged incorrectly, including 14 cases of T staging, of which 8 cases were due to not distinguishing T2 and T3 correctly, and 8 cases of N staging, of which 5 cases were due to not distinguishing lymphadenitis and metastatic lymph nodes correctly. CONCLUSIONS: The accuracy rate of EUS is high for preoperative staging of esophageal carcinoma, especially for T3 and mediastinum lymph node. Distinguishing T2 and T3, lymphadenitis and metastatic lymph nodes correctly and diagnosing abdomen lymph node metastasis can improve the diagnosis accuracy rate of EUS.

[Vascular endothelial growth factor expression and microvessel density in stage I-II non-small cell lung cancer and their prognostic significances].

BACKGROUND & OBJECTIVE: TNM staging system is used widely to predict prognosis of non-small cell lung carcinoma (NSCLC) patients, but patients with the same stage may have very different survivals; better prognostic index is needed. Angiogenesis is considered to be essential for tumor development, progression, and metastasis, but the prognostic impacts of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in NSCLC is controversial. This study was to evaluate the prognostic value of VEGF and MVD in NSCLC. METHODS: VEGF and MVD in 214 specimens of stageI-II NSCLC (20 in stage IA, 137 in stage IB, and 57 in stage IIB) were detected by tissue chip and SP immunohistochemistry. No patient underwent postoperative antitumor treatment. RESULTS: VEGF expression didn't relate to gender, age, blood type, pathologic type, and TNM stage (P0.05). MVD correlated with age and pathologic type (P0.05), but did not relate to gender, blood type, and TNM stage (P0.05). The mean value of MVD was 65.8+/-5.2 in VEGF-low patients, and 67.5+/-2.5 in VEGF-high patients (P0.05). The 5-year survival rate was significantly lower in MVD-high patients than in MVD-low patients (34.5% vs. 60.0%, P=0.013). Furthermore, multivariate Cox regression analysis showed that MVD (P=0.000) was an independent prognostic factor of NSCLC. CONCLUSION: High MVD closely relates to poor prognosis of stageI-II NSCLC.

[Expression correlation of Ki67 to P53,VEGF,and C-erbB-2 genes in breast cancer and their clinical significances].

BACKGROUND & OBJECTIVE: The proliferating antigen Ki67 is an important biological marker in cell proliferation. This study was designed to investigate the expressions of Ki67, P53, vascular endothelial growth factor (VEGF),and C-erbB-2 in breast cancer tissue, and their correlations with cliniopathological significance. METHODS: The expressions of Ki67,p53,VEGF,and C-erbB-2 in 151 cases of breast cancer were assessed by immunohisto-chemistry, and their correlations with clinicopathological factors were statistically analyzed. RESULTS: The positive rate of Ki67 was 78.2%(113/151). The expression of Ki67 correlated with tumor stages (P< 0.05), but didn't relate to age, tumor size, and lymph node status (P >0.05). In addition,the expression of Ki76 had a positive correlation with the expressions of p53, and C-erbB-2 (P< 0.05), but not with the expression of VEGF (P >0.05). The co-expression of Ki67 and VEGF related to tumor size,and clinical stage (P< 0.05). CONCLUSIONS: The expression of Ki67 is an objective biological marker for estimating the occurrence and progression of breast cancer. Combined detection of Ki67 and VEGF may helps to judge the clinical stage of breast cancer.

[Shrinkage of resected specimens of esophageal carcinoma].

BACKGROUND & OBJECTIVE: There are some kinds of shrinkage in resected specimens of esophageal carcinoma; however,there were few reports on its regularity. This study was designed to investigate the degree of shrinkage in resected specimens of esophageal carcinoma. METHODS: Specimens of seventy patients with esophageal squamous cell carcinoma who underwent resections in Cancer Center, Sun Yat-Sen University were collected. The length of the upper margin,the tumor,and the lower margin were measured with a ruler during operation before the esophagus was removed (in situ). After the esophagus was removed, the specimens were cut longitudinally on the side opposite the tumor, then the length of the upper margin, the tumor, and the lower margin were measured again without retraction. After 48 h fixation of 10% formalin (fixed), the length of the upper margin, the tumor, and the lower margin were measured again. RESULTS: After resection,the shrinkage rates of the upper margin, the tumor,and the lower margin were (40.71+/-10.02)%,(83.59+/-16.57)%, and (58.41+/-12.03)% of their in situ length; after 48 h fixation of 10% formalin, the shrinkage rates of the upper margin,the tumor, and the lower margin were (40.06+/-10.50)%, (80.92+/-15.88)%, and (54.83+/-11.29)% of their in situ length (P< 0.05). CONCLUSION: The specimens of esophageal carcinoma shrink remarkably after removed and after formalin fixation.