Objective To evaluate the significance of expression of hMLH1 and hMSH2 in detecting hereditary nonpolyposis colorectal carcinoma (HNPCC). Methods Colorectal carcinomas from 66 patients were examined by immunohistochemistry for the expressions of hMLH1 and hMSH2 using commercially available monoclonal antibodies. Immunohistochemical patterns of tumors from 19 HNPCC patients (Group A), 20 suspected HNPCC patients (Group B), 14 patients whose clinical features conformed to the Bethesda guideline (Group C), and 13 sporadic colorectal cancer patients (Group D) were compared. Results The absence or low expression of hMLH1 and hMSH2 was revealed in 72.8% patients of group A, 60.0% in group B, 28.4% in group C and 7.7% in group D. The absence or low protein expression of hMLH1 and hMSH2 was significantly correlated with HNPCC (P=0.0008). The absence or low expression of hMLH1 was higher detection rate than that hMSH2 (P=0.01). Conclusions HNPCC patients can be identified by immunohistochemical methods according to the expression of hMLH1 and hMSH2, which may be used in clinical practice and research. Immunohistochemical analysis of hMLH1 and hMSH2 may predict the presence of corresponding gene mutations. Gene mutation in hMLH1 might be higher than that in hMSH2 in Chinese HNPCC.

Objective:To explore the role of DKK-1 andβ-catenin expressions in progression of proximal gastric cancer (PGC). Methods:The expression of DKK-1 andβ-catenin in 61 cases with PGC and para-neoplastic tissues and 20 cases with normal gastric mucosa was detected by immunohistochemistry. The related clinical significance in the cases was studied. Results:The positive expression rate of DKK-1 and the abnormal expression rate ofβ-catenin in the tissue sections of PGC were 34.4%(21/61) and 68.9%(42/61), respectively. The positive expression rate of DKK-1 and the abnormal expression rate ofβ-catenin in para-carcinoma tissues were 8.2%(5/61) and 6.6%(4/61) , respectively. The positive expression rate of DKK-1 and the abnormal expression rate ofβ-catenin in normal gastric mucosa were 15.0%(3/20) and 10.0%(2/20), respectively. The expression rate was significantly higher in PGC than that in the other tissues (P<0.05). The expression of DKK-1 was positively related to that ofβ-catenin in PGC (r=0.454, P<0.05), but not in the others. Conclusion:Higher expressions of DKK-1 and the abnormal expression ofβ-catenin are closely related to the occurrence of PGC.

Objective:To introduce a new fixation set-up for micro-tensile test.Methods:Dentin-composite were bonded with AdperTM Single Bond 2 (SB2)and sectioned into stick-shaped specimens.Specimens from each tooth(n =6)were equally divided into Ciucchi's jig and the designed set-up(Control and experimental)groups for micro-tensile bond test according to the utilized fixa-tion set-up.The bonding interface failure mode was examined with field-emission scanning electron microscope (FESEM).Three-dimensional models of the two set-ups and the specimen were developed,stress distribution was analyzed by finite element analysis (FEA).Results:The bond strength(MPa)of experimental and control group was 32.76 ±7.43 and 43.58 ±4.72(P <0.05),the ratio of mixed failure was 28 /36 and 20 /36(P <0.05)respectively.FEA showed that the designed set-up for fixing the sticks pro-vided a uniform stress distribution along the long axis of the specimen.FEA and failure mode analysis confirmed such uniform distri-bution was also concentrated at the bonding interface.Conclusion:The new set-up is feasible for micro-tensile test.

OBJECTIVETo introduce the method of dual immunofluorescence labeling of human dentin matrix without demineralization of the whole dentin fragments, and to analyze the distribution of type-I collagen fibrils and chondroitin sulfate in human dentin.

METHODSForty 30 µm- thick middle coronal dentin sections were obtained from 8 freshly extracted human third molars and etched with 37% phosphoric acid(PA) gel for 15 s. After preconditioning with or without tosyl- phenylalanyl chloromethyl ketone(TPCK) treated trypsin digestion, sections were subjected to dual immunofluorescent labeling and scanned by confocal laser scanning microscopy to identify the type-I collagen fibrils and chondroitin sulfate.

RESULTSChondroitin sulfate was localized in the lumens of the dentin tubules and peritubular dentin, while the type-I collagen fibrils were localized in intertubular dentin and peritubular dentin. After preconditioning with TPCK treated trypsin digestion, the red fluorescence was decreased or disappeared.

CONCLUSIONSThe dual immunofluorescence labeling methodology can be used to study the human dentin matrix without demineralization of the whole dentin fragments. Chondroitin sulfate was localized in the lumens of the dentin tubules and peritubular dentin, while the type-I collagen fibrils were localized in intertubular dentin and peritubular dentin.

Acid Etching, Dental ; methods ; Chondroitin Sulfates ; analysis ; Collagen Type I ; analysis ; Dentin ; chemistry ; Extracellular Matrix ; Fluorescent Antibody Technique ; methods ; Humans ; Microscopy, Confocal ; Molar ; Phosphoric Acids

OBJECTIVETo investigate the potential effect of proteoglycan (PG) and glycosaminoglycan (GAG) on the bonding of etch and rinse adhesive to dentin, in order to improve the bonding effect of dentin.

METHODSForty-two extracted molars were used to obtain standard dentin bonding surface, and the specimens were etched for 15 s with 37% phosphoric acid and divided into three groups using a table of random numbers. Then the three groups undergone different incubating procedures as follow: specimens in chondroitinase ABC (C-ABC) group were incubated with C-ABC at 37 °C for 48 h in vibrator. Specimens in trypsin (TRY) group were incubated with trypsin, and specimens in the control group were incubated with deionized water for 48 h in the oscillators. Then specimens in each group were randomly assigned into two subgroups, A (Adper(TM) Single Bond 2) and B (Prime & Bond NT) (n = 7). The microtensile bond strength (µTBS), fracture mode and bonding interface morphology of the specimens were evaluated via microtensile testing, stereo microscope and field emission scanning electron microscopy (FE-SEM) respectively after specimens being incubated in 37 °C water for 24 h.

RESULTSThe immediate µTBS of C-ABC group bonding with adhesive A and B [(32.9±2.5) and (26.8±2.2) MPa] were significantly lower than that of the control group [(40.7±3.3) and (34.6±3.7) MPa] (P < 0.05). While the immediate µTBS of TRY group [(49.0 ± 3.6) and (44.5 ± 3.0) MPa] were significantly higher than that of the control group(P < 0.05).

CONCLUSIONSDentin PG participates in the dentin bonding process. Removal of PG increased the immediate µTBS of dentin and total etching adhesives, while removal of GAG decreased the immediate µTBS.

Acid Etching, Dental ; methods ; Bisphenol A-Glycidyl Methacrylate ; pharmacology ; Chondroitin ABC Lyase ; pharmacology ; Dental Bonding ; Dental Stress Analysis ; Dentin ; chemistry ; Dentin-Bonding Agents ; pharmacology ; Glycosaminoglycans ; pharmacology ; Hot Temperature ; Humans ; Phosphoric Acids ; Polymethacrylic Acids ; Proteoglycans ; pharmacology ; Random Allocation ; Resin Cements ; Tensile Strength ; drug effects ; Trypsin ; pharmacology

Objective:To investigate the value of total laparoscopic simultaneous resection for left-sided colorectal cancer (CRC) and synchronous liver metastases (SLM).Methods:A retrospective analysis of the clinical data of patients with left-sided CRC and SLM who underwent simultaneous resection in the Shanghai Cancer Center, Fudan University from March 2014 to December 2017. The patients were divided into laparoscopy group, open surgery group and hybrid surgery group. The intraoperative information, postoperative short-term outcome and long-term survival were analyzed among the three groups.Results:A total of 96 patients were enrolled. The total laparoscopic group enrolled 29 patients, including 21 males and 8 females, aged (57.8±1.6) years old; the open surgery group enrolled 28 patients, including 18 males and 10 females, aged (57.3±2.0) years old; 39 cases were included in the hybrid surgery group, including 27 males and 12 females, aged (55.3±1.8) years old. The distribution ratio of the two lobes of liver metastases in the open surgery group was higher than that in the total laparoscopic group and hybrid surgery group (all P<0.05), and there was no significant difference in the other clinical baseline characteristics between the three groups (all P>0.05). In laparoscopy group, open surgery group and hybrid surgery group, the mean operative time was (241.5±12.9) min, (209.3±10.7) min and (234.9±12.4) min, respectively. The median intraoperative blood loss was 200.0 ml, 300.0 ml and 200.0 ml, respectively. The median postoperative hospital stay was 8.0 days, 9.0 days and 9.0 days, respectively. There were no statistical differences in these indicators (all P>0.05). The patients in the open surgery group had a longer initial defecation time than those in the other two groups ( P<0.05). The incidence of postoperative complications was 31.0% (9/29), 39.3% (11/28) and 35.9% (14/39), respectively, with no difference among the three groups ( P>0.05). In laparoscopy group, open surgery group and hybrid surgery group, 1-year overall survival were 93.0%, 85.0% and 94.0%; 3-year overall survival were 72.0%, 81.0% and 74.0%, respectively ( P>0.05). One-year disease free survival were 70.0%, 52.0% and 55.0%; 3-year disease free survival were 36.0%, 30.0% and 39.0%, respectively ( P>0.05). Conclusion:Laparoscopic simultaneous resection for left-sided CRC and SLM shows slight advantages in the safety and short-term outcome, and does not affect the long-term survival.

Objective: To investigate the potential effect of proteoglycans (PG) and glycosaminoglycans (GAG) on the stability of resin-dentin bonds against artificial saliva storage. Methods: Seventy-two extracted molars were used to obtain standard dentin bonding surface, and the specimens were etched for 15 s with 37% phosphoric acid and divided into three groups using a table of random number. Then the three groups undergone different incubating procedures as follow: specimens in chondroitinase ABC (C-ABC) group were incubated with C-ABC, specimens in trypsin (TRY) group were incubated with trypsin, and specimens in the control group were incubated with deionized water. All specimens were incubated at 37 ℃ for 48 h in the oscillators. Then specimens in each group were randomly assigned into three subgroups (n=8) as follows: immediate control subgroup, aging subgroups with artificial saliva storage for 6 months and 12 months. Microtensile bond strength (μTBS), fracture mode, bonding interface morphology and nanoleakage were evaluated. Results: Immediately and with artificial saliva storage for 6 months and 12 mouths, the μTBS of TRY group ([49.04±3.57], [37.01±3.21] and [35.27±3.56] MPa) were significantly higher than those in the control group ([40.71±3.32], [28.87±2.34] and [24.20±2.07] MPa) (P<0.05). The immediate μTBS of C-ABC group ([32.94±2.45] MPa) was significantly lower than that of the control group (P<0.05). While with artificial saliva storage for 6 months and 12 mouths, the μTBS of C-ABC group ([26.46±2.45] and [22.50±2.58] MPa) were no differences with those of the control group (P>0.05). The ratio of cohesive fracture increased with the extension of aging time. Some narrow gaps were found in hybrid layer of the control group with artificial saliva storage for 6 months and 12 mouths. Conclusions Removal of PG increased the μTBS and durable bonds to dentin, while removal of GAG decreased the μTBS, however, it can be of help to create more durable bonds to dentin.