Construction of silver-coated high translucent zirconia implanting abutment material and its property of antibacterial.

High translucent zirconia (HTZ) has excellent mechanical properties, biocompatibility, and good semi-translucency making it an ideal material for aesthetic anterior dental implant abutments without antibacterial properties. In the oral environment, the surface of the abutment material is susceptible to microbial adhesion and biofilm formation, which can lead to infection or peri-implantitis and even implant failure. This study aims to promote the formation of a biological seal at the implant-soft tissue interface by modifying the HTZ surface, using the load-bearing capacity of the aluminosilicate porous structure and the broad-spectrum antibacterial effect of silver nanoparticles to prevent peri-implant bacterial infection and inflammation and to improve the success rate and prolong the use of the implant. FE-SEM (field emission scanning electron microscopes), EDS (energy dispersive spectroscopy), and XPS (X-ray photoelectron spectroscopy) results showed that aluminosilicate non-vacuum sintering can form open micro- and nanoporous structures on HTZ surfaces, and that porous aluminosilicate coatings obtain a larger number, smaller size, and more uniformly shaped silver nanoparticles than smooth aluminosilicate coatings, and could be deposited deeper in the coating. The ICP-AES (inductively coupled plasma-atomic emission spectroscopy) results showed that the early silver ion release of both the smooth silver coating and the porous silver coating was obvious, the silver ion concentration released by the former was higher than that of the latter. However, the silver ion concentration released by the porous silver coating was higher than that of the smooth coating when the release slowed down. Both smooth and porous silver coatings both inhibited E. coli (Escherichia coli), S. aureus (Staphylococcus aureus), and L. acidophilus (L. acidophilus), and porous silver coatings had stronger antibacterial properties. The silver coating was successfully constructed on the surface of HTZ, through aluminium silicate sintering and silver nitrate solution impregnation. It was found that the high concentration environment of silver nitrate solution was more advantageous for nano-Ag deposition, and the non-vacuum sintered porous surface was able to obtain a larger number of nano-Ag particles with smaller sizes. The porous Ag coating exhibited superior antibacterial properties. It was suggested that the HTZ with silver coating had clinical application, and good antibacterial properties that can improve the survival rate and service life of implants.

A retrospective study comparing D1 limited lymph node dissection and D2 extended lymph node dissection for N3 gastric cancer.

BACKGROUND: In countries in East Asia, the typical treatment for curable gastric cancer is gastrectomy with D2 lymphadenectomy. However, whether D2 lymphadenectomy is beneficial for high-risk N3 node disease remains controversial. We conducted a multi-institution retrospective study on patients with high-risk, locally advanced gastric cancer. To compare the rates of disease-free survival (DFS) and overall survival (OS) between radical D2-type gastric resection and lymphadenectomy and the more limited D1 type resection and lymphadenectomy. METHODS: From July 2010 to June 2015, 74 patients out of 949 who underwent curative-intent R0 surgery were selected in pairs to compare the survival outcomes between those who underwent radical D2 type (n=37) vs. the more limited D1 type (n=37) gastric resection and lymphadenectomy. RESULTS: The median DFS was 9.72 and 7.81 months for the D2 and D1 types, respectively (P=0.746), and the OS was 16.39 and 15.85 months for the D2 and D1 types, respectively (P=0.937). CONCLUSIONS: No statistically significant differences in DFS and OS were noted between D1 and D2 procedures for those with N3 disease. Our results support the hypothesis that a novel multidisciplinary approach rather than a surgical approach alone is needed to improve the survival outcomes of high-risk patients with N3 gastric cancer.

Long non-coding RNA PlncRNA-1 promotes cell proliferation and hepatic metastasis in colorectal cancer.

Emerging evidence has identified that long non-coding RNAs (lncRNAs) may play an important role in the pathogenesis of many cancer types, including colorectal cancer (CRC). However, the role of PlncRNA-1 in CRC remains unclear. The aim of our present study was to investigate the potential functions of PlncRNA-1 in CRC and to identify the underlying mechanisms of action. We demonstrated that up-regulated PlncRNA-1 in CRC tissues and cells promoted cell proliferation by accelerating cell cycle process and inhibiting cell apoptosis in vitro, enhanced tumor growth and matastasis in vivo and was associated with cell migration and invasion, EMT process of CRC cells. In addition, PlncRNA-1 was a target of miR-204 and enhanced the expression of an endogenous miR-204 target, MMP9 in CRC cells. Furthermore, we found that PlncRNA-1 activates Wnt/ß-catenin pathway through the miR-204 in CRC cells. These results suggest that the PlncRNA-1/miR-204/ Wnt/ß-catenin regulatory network may shed light on tumorigenesis in CRC.

[Review on the genomic imprinting at the mammalian DLK1-DIO3 cluster.].

The mammalian imprinting domain DLK1-DIO3 is located on distal human chromosome 14, mouse chromosome 12 and sheep chromosome 18. This cluster contains three imprinted protein-coding genes (Dlk1, Rtl1, and Dio3), which were expressed from the paternally inherited chromosome and several imprinted noncoding RNA genes expressed from the maternally inherited allele, such as miRNAs, snoRNAs, and large noncoding RNA Gtl2. The altered gene dosage of DLK1-DIO3 cluster resulted in several severe abnormal phenotypes in human and mouse, even death, suggesting the importance of these genes for normal development. This review focuses on the function of imprinted genes on this domain and the mechanism of their imprinting regulation.

[Expression of phosphatase of regeneration liver-3 in human colorectal carcinoma and its prognosis value].

OBJECTIVE: To investigate the expression of phosphatase of regeneration liver-3(PRL-3) protein and its relationship with tumor invasion and metastasis in human colorectal carcinoma,and elucidate prognostic value. METHODS: Immunohistochemistry method was applied to detect the PRL-3 expression in the primary tumor specimens and paired paratumor normal tissues from 46 colorectal carcinoma patients, the adenoma tissues from 6 patients with colorectal adenoma, all the metastatic lymph nodes from 29 cases and the metastatic liver lesions from 6 cases. The relationship between PRL-3 expression and clinicopathologic parameters was analyzed and a survival curve was achieved according to Kaplan-Meier method. RESULTS: No or weak PRL-3 protein expression was detected in normal colorectal mucosa and colorectal adenoma. In colorectal carcinoma tissues, PRL-3 expression was confirmed in 26 of 46 cases (56.5%) of primary colorectal carcinomas (with lymph node metastasis 63.0%, without lymph node metastasis 37.0%, P=0.001), 26 of 29 (89.7%) lymph node metastases, and 5 of 6 liver metastases. The expression of PRL-3 was assembled in the cytoplasm of carcinoma cells and more intensively on the cell membrane.Analysis of the relationship between PRL-3 expression and the clinicopathologic features showed that PRL-3 expression was closely associated with tumor stage (P=0.019), lymph node metastasis (P=0.026), but no relationship with age, sex, tumor size, degree of differentiation was founded (P<0.05). The mean follow-up time was 41.4 months and results showed that patients with positive expression of PRL-3 had a significantly poorer prognosis than those with negative PRL-3 expression group(P=0.032). CONCLUSIONS: PRL-3 protein plays a novel role in tumor progression and metastasis of colorectal carcinoma. PRL-3 can be expected to be a potential predictive biomarker for identifying the prognosis in colorectal carcinoma patients.

[Study with large slice technique and tissue microarray on lymph node involvement and micro-metastasis of rectal cancer].

OBJECTIVE: To study lymph node involvement and micro-metastasis of rectal cancer with large slice technique and tissue microarray. METHODS: Large slice technique, combined with tissue microarray,was used in pathologic study of 31 patients after total mesorectal excision (TME) for rectal cancer. RESULTS: Nine hundred and ninety- two lymph nodes were harvested and 148 were positive. More than 40% of positive lymph nodes were located in the outer layer of the mesorectum and in the same side of the mesorectum as the primary tumor was. Circumferential margin involvement was observed in 12 cases and correlated with the numbers of metastatic lymph nodes (Beta =1.166, P=0.041). Micrometastasis was found in 9 cases with negative pathological lymph nodes, but not correlated with tumor differentiation and stage (P> 0.05). CONCLUSION: Large slice technique combined with tissue microarray facilitates the detection of lymph node involvement and micrometastasis. There is a predominance of lymph node metastasis in the outer layer and the same side of the mesorectum. Micrometastasis can be discovered in different stages of rectal cancer.

[Evaluation of clinical necessity of gastrointestinal decompression after excision and anastomosis of lower digestive tract].

OBJECTIVE: To evaluate the clinical necessity of postoperative gastrointestinal decompression after operation on lower digestive tract. METHODS: Three hundred and sixty-eight patients who required excision and anastomosis of lower digestive tract were randomly divided into two groups, with or without receiving gastrointestinal decompression after operation. Clinical therapeutic efficacy and complications were compared between two groups. RESULTS: The volume of gastrointestinal suction ranged from 10 ml to 520 ml each day after operation, and was less on the first day than those on the second and the third day after operation in decompression group. There was no significant difference in the average girth between two groups before and after operation. The average girths were shorter before operation than those after operation in two groups (P< 0.001). There was no significant difference in postoperative defecation and urination time between two groups (P > 0.05). The complication rate was significantly higher in decompression group than that in non-decompression group (28% vs. 8.2%, P< 0.001). The incidence of pharyngolaryngitis was up to 23.1% in decompression group. There was no difference in hospital stay between the two groups after operation. CONCLUSION: The recovery of patients who receive excision and anastomosis of lower digestive tract will benefit from non-gastrointestinal decompression.

[Expression of phosphatase of regenerating liver-3 mRNA and its clinical implications in human colorectal carcinoma].

OBJECTIVE: To investigate the expression of phosphatase of regenerating liver-3 (PRL- 3) mRNA and evaluate its relationship with tumor invasion and metastasis in human colorectal carcinoma. METHODS: The expression level of PRL-3 mRNA was examined semi-quantitatively in surgically resected tumor specimens, paired paratumor normal tissues from 46 CRC patients, metastatic lymph nodes and liver metastases from 18 cases with metastasis,adenoma tissues from 6 patients with colorectal adenoma (CRA). In addition,the mutation of PRL-3 gene was examined by PCR-SSCP. RESULTS: The PRL-3 mRNA level was increased in primary CRC tissues as compared with paired paratumor normal tissues (1.6+/- 0.7 vs. 0.4+/- 0.1, P< 0.01), while no significant difference of its expression was found between CRA tissues and their adjacent normal mucosae (P> 0.05). However,the PRL-3 mRNA levels of liver metastases (2.1+/- 0.8) in 12 cases and metastatic lymph nodes (3.3+/- 1.0) in 6 cases were significantly higher compared with the matched primary lesions, normal tissues and negative-lymph nodes (P< 0.01). There was significant relation of the expression of PRL-3 mRNA with the clinicopathological features including Dukes stage, invasion depth and metastasis (P< 0.05), but no relation with sex,tumor size,degree of differentiation was found (P> 0.05). Abnormal electrolysis band was found in 1 of 6 cases with liver metastasis by PCR-SSCP analysis. CONCLUSION: PRL-3 gene plays an important role in tumor invasion and metastasis and may associated with carcinogenesis and development of CRC. There might exist some unknown mechanisms of overexpression and mutation of PRL-3 gene in CRC.

Mesorectal spread and micrometastasis of rectal cancer studied with large slice technique and tissue microarray.

BACKGROUND AND OBJECTIVES: Mesorectal tissue seems to be an ideal substrate for the spreading of tumors. The aim was to study the distribution of mesorectal neoplastic foci, examine occurrence of circumferential margin involvement and investigate micrometastasis of the lymph nodes. METHODS: A large slice technique, combined with tissue microarray, was used in the pathologic study of 31 specimens operated on following the principles of total mesorectal excision (TME). RESULTS: Three hundred and forty-nine mesorectal neoplastic foci were examined from 18 specimens. Almost one third of them were in the outer layer of mesorectum. Concerning position of primary tumor, ipsolateral neoplastic foci were significantly more than contralateral neoplstic foci. Twelve specimens were diagnosed to have circumferential margin involved. Nine hundred and ninety-two lymph nodes were harvested with 148 involved by tumor. No significant difference in occurrence of micrometastasis was observed among tumors of different stage. CONCLUSION: Combination of large slice and tissue microarray provided a more detailed method in studying the spread of rectal cancer. Complete excision of the mesorectum with fascia propria circumferentially intact is essential since there is an outer scattering and lateral discrepancy for neoplastic foci distribution. Circumferential margin involvement and micrometastasis observed suggested adoption of preoperative and/or postoperative radiochemotherapy.

Nodal spread and micrometastasis within mesorectum.

AIM: To study the distribution of positive lymph nodes within mesorectum and to investigate the possible micrometastasis in negative lymph nodes. METHODS: Large slice technique combined with tissue microarray was used in the pathologic study of 31 specimens. RESULTS: A total of 992 lymph nodes were harvested and cancer metastasis was found in 148 lymph nodes. Some positive lymph nodes were located in the outer layer of mesorectum and more at the same site of mesorectum as the primary tumor. Circumferential margin lymph node metastasis was observed in nine cases. No significant difference in occurrence of micrometastasis was observed in different stage tumors. CONCLUSION: Positive lymph nodes are distributed in mesorectum and micrometastasis can be found in negative lymph nodes.

Pituitary adenylate cyclase activating-peptide and its receptor antagonists in development of acute pancreatitis in rats.

AIM: Pituitary adenylate cyclase activating-peptide (PACAP) is a late member of the secretin/glucagon/vasoactive intestinal peptide (VIP) family of brain-gut peptides. It is unknown whether PACAP takes part in the development of acute pancreatitis and whether PACAP or its antagonists can be used to suppress the progression of acute pancreatitis. We investigated the actions of PACAP and its receptor antagonists in acute pancreatitis on rats. METHODS: Acute pancreatitis was induced in rats with caerulein or 3.5% sodium taurocholate. The rats were continuously infused with 5-30 microg/kg PACAP via jugular vein within the first 90 min, while 10-100 microg/kg PACAP6-27 and (4-Cl-D-Phe6, Leu17) VIP (PACAP receptor antagonists) were intravenously infused for 1 h. Biochemical and histopathological assessments were made at 4 h after infusion. Pancreatic and duodenal PACAP concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Chinese ink-perfused pancreas was fixed, sectioned and cleared for counting the functional capillary density. RESULTS: PACAP augmented caerulein-induced pancreatitis and failed to ameliorate sodium taurocholate-induced pancreatitis. ELISA revealed that relative concentrations of PACAP in pancreas and duodenum were significantly increased in both sodium taurocholate- and caerulein-induced pancreatitis compared with those in normal controls. Unexpectedly, PACAP6-27 and (4-Cl-D-Phe6, Leu17) VIP could induce mild acute pancreatitis and aggravate caerulein-induced pancreatitis with characteristic manifestations of acute hemorrhagic/necrotizing pancreatitis. Functional capillary density of pancreas was interpreted in the context of pancreatic edema, and calibrated functional capillary density (calibrated FCD), which combined measurement of functional capillary density with dry weight/wet weight ratio, was introduced. Hyperemia or congestion, rather than ischemia, characterized pancreatic microcirculatory changes in acute pancreatitis. CONCLUSION: PACAP may take part in the pathogenesis of acute pancreatitis in rats. The two PACAP receptor antagonsits might act as partial agonists. Calibrated functional capillary density can reflect pancreatic microcirculatory changes in acute pancreatitis.

Pathological study of distal mesorectal cancer spread to determine a proper distal resection margin.

AIM: Local recurrence after curative surgical resection for rectal cancer remains a major problem. Several studies have shown that incomplete removal of cancer deposits in the distal mesorectum contributes a great share to this dismal result. Clinicopathologic examination of distal mesorectum in lower rectal cancer was performed in the present study to assess the incidence and extent of distal mesorectal spread and to determine an optimal distal resection margin in sphincter-saving procedure. METHODS: We prospectively examined sepecimens from 45 patients with lower rectal cancer who underwent curative surgery. Large-mount sections were performed to microscopically observe the distal mesorectal spread and to measure the extent of distal spread. Tissue shrinkage ratio was also considered. Patients with involvement in the distal mesorectum were compared with those without involvement with regard to clinicopathologic features. RESULTS: Mesorectal cancer spread was observed in 21 patients (46.7%), 8 of them (17.8%) had distal mesorectal spread. Overall, distal intramural and/or mesorectal spreads were observed in 10 patients (22.2%) and the maximum extent of distal spread in situ was 12 mm and 36 mm respectively. Eight patients with distal mesorectal spread showed a significantly higher rate of lymph node metastasis compared with the other 37 patients without distal mesorectal spread (P = 0.043). CONCLUSION: Distal mesorectal spread invariably occurs in advanced rectal cancer and has a significant relationship with lymph node metastasis. Distal resection margin of 1.5 cm for the rectal wall and 4 cm for the distal mesorectum is proper to those patients who are arranged to receive operation with a curative sphincter-saving procedure for lower rectal cancer.

[Mesorectal spread and circumferential margin involvement of rectal cancer studied on large slice].

OBJECTIVE: To provide the mode of cancer distribution in the mesorectum and circumferential resection margin. METHODS: Large slice technique was used in the pathologic study of 62 specimens operated on following the principles of total mesorectal excision (TME). RESULTS: More than 40% of all the observed neoplastic foci were located in the outer layer of the mesorectum in Stage III patients. Further analysis of the foci's localities with respect to the primary tumor's locality showed that ipsolateral neoplastic foci (44.44%) were significantly more than the contralateral neoplastic foci (13.33%) in the mesorectum (P<0.05). Extramural distal spread was found in 8 cases with the maximum extent of 3.5 cm. No significant difference in occurrence of circumferential margin involvement (CMI) was observed among tumors of different location, but tumors of poorer differentiation were noted to have a higher risk of CMI. CONCLUSION: Large slice technique offers a whole image of rectum, mesorectum, together with the position of neoplastic foci. There are outer preponderance and lateral discrepancy of neoplastic foci distribution in the mesorectum. A distal clearance margin of 4 cm would be mandatory. We advocate the adoption of TME as the baisc surgical principles in treating patients with rectal cancer and in avoiding surgery-related circumferential margin involvement.

Microscopic spread of low rectal cancer in regions of mesorectum: pathologic assessment with whole-mount sections.

AIM: To assess the microscopic spread of low rectal cancer in mesorectum regions to provide pathological evidence for the necessity of total mesorectal excision (TME). METHODS: A total of 62 patients with low rectal cancer underwent low anterior resection and TME, surgical specimens were sliced transversely on the serial embedded blocks at 2.5 mm interval, and stained with hematoxylin and eosin (HE). The mesorectum on whole-mount sections was divided into three regions: outer region of mesorectum (ORM), middle region of mesorectum (MRM) and inner region of mesorectum (IRM). Microscopic metastatic foci were investigated microscopically on the sections for the metastatic mesorectal regions, frequency, types, involvement of lymphatic vessels and correlation with the original rectal cancer. RESULTS: Microscopic spread of the tumor in mesorectum and ORM was observed in 38.7% (24/62) and 25.8% (16/62) of the patients, respectively. Circumferential resection margin (CRM) with involvement of microscopic metastatic foci occurred in 6.5% (4/62) of the patients, and distal mesorectum (DMR) involved was 6.5% (4/62) with the spread extent within 3 cm of low board of the main lesions. Most (20/24) of the patients with microscopic metastasis in mesorectum were in Dukes C stage. CONCLUSION: Results of the present study support that complete excision of the mesorectum without destruction of the ORM is essential for surgical management of low rectal cancer, an optimal DMR clearance resection margin should be no less than 4 cm, further pathologic assessment of the regions in extramesorectum in the pelvis is needed.

Gastrointestinal decompression after excision and anastomosis of lower digestive tract.

AIM: To discuss the clinical significance of postoperative gastrointestinal decompression in operation on lower digestive tract. METHODS: Three hundred and sixty-eight patients with excision and anastomosis of lower digestive tract were divided into two groups, i.e. the group with postoperative gastrointestinal decompression and the group without postoperative gastrointestinal decompression. Clinical therapeutic outcome and incidence of complication were compared between two groups. Furthermore, an investigation on application of gastrointestinal decompression was carried out among 200 general surgeons. RESULTS: The volume of gastric juice in decompression group was about 200 mL every day after operation. Both groups had a lower girth before operation than every day after operation. No difference in length of the first passage of gas by anus and defecation after operation was found between two groups. The overall incidence of complications was obviously higher in decompression group than in non-decompression group (28% vs 8.2%, P<0.001). The incidence of pharyngolaryngitis was up to 23.1%. There was also no difference between two groups regarding the length of hospitalization after operation. The majority (97.5%) of general surgeons held that gastrointestinal decompression should be placed till passage of gas by anus, and only 2.5% of surgeons thought that gastrointestinal decompression should be placed for 2-3 d before passage of gas by anus. Nobody (0%) deemed it unnecessary for placing gastrointestinal compression after operation. CONCLUSION: Application of gastrointestinal decompression after excision and anastomosis of lower digestive tract cannot effectively reduce gastrointestinal tract pressure and has no obvious effect on preventing postoperative complications. On the contrary, it may increase the incidence of pharyngolaryngitis and other complications. Therefore, it is more beneficial to the recovery of patients without undergoing gastrointestinal decompression.