A Comparative Study of Stability After the Installation of 2 Different Surface Types of Implants in the Maxillae of Dogs

PURPOSE

This study was performed to investigate the histologic and histomorphometric findings of 2 different types of implant.

MATERIALS AND METHODS

Resorbable blasting media (RBM) and sandblasted with larger grit and acid etched (SLA) surfaced implants (24 fixtures in each group) were installed in posterior maxilla of dogs. The initial stability was measured using Periotest (Periotest value [PTV]). After 6 or 12 weeks, fixtures with surrounding bone were harvested.

RESULTS

The average initial stability of the SLA group (-1.71 ± 2.9) was higher than that of the RBM group (-1.25 ± 3.21), but there was no significant difference. The mean PTV of the RBM surface was higher than the SLA surface at 12 weeks. The average bone-implant contacts were 67.6% ± 16.0% at 6 weeks and 82.7% ± 8.6% at 12 weeks in the SLA group and 69.9% ± 17.6% at 6 weeks and 78.3% ± 9.2% at 12 weeks in the RBM group.

CONCLUSION

The SLA and resorbable blasting media (RBM) surface implants demonstrated good stabilities and healing processes of the surrounding bone in the posterior maxilla. Therefore, the two domestic implants could provide predictable clinical results.

Pathological significance of connexin 26 expression in colorectal adenocarcinoma

This study was conducted to determine the level of expression and cellular localization of connexin 26 (Cx26) and the expression of p53 in colorectal adenocarcinoma as well as their relationship to clinicopathological features. Immunohistochemical staining was performed in 130 colorectal adenocarcinoma cases. A correlation between the expression levels of the two proteins and an analysis of the clinicopathological features of the samples was performed. There was a statistical significant difference in the Cx26 expression level among normal epithelium (NE), adenomas and adenocarcinomas (p<0.001). Of the 130 adenocarcinomas, 48.5% were positive for Cx26. All of the adenoma and NE samples were positive for Cx26 expression; however, the level of expression of Cx26 in adenomas was smaller than the level of expression for NE. Cytoplasmic staining for Cx26 was observed in the adenocarcinomas (23.8%), but was not observed in the adenoma and NE samples. A positive correlation between a reduction in intercellular Cx26 and tumor invasion was statistically significant (p<0.05). Expression of p53 was positive for 50% of the adenocarcinomas, and the level of p53 was increased in a reverse proportion to the level of Cx26 intercellular staining. In conclusion, loss of intercellular and gain of intracytoplasmic Cx26 expression may play a role in colorectal carcinogenesis and tumor progression.

Sodium salicylate switches glucose depletion-induced necrosis to autophagy and inhibits high mobility group box protein 1 release in A549 lung adenocarcinoma cells

Sodium salicylate, the active metabolite of aspirin, has been shown to exert anti-inflammatory activities by inhibiting the expression of various pro-inflammatory factors, and has potent anti-cancer effects against a number of human cancers including colon, lung, breast and leukemia. Necrotic cell death is emerging as one of the crucial factors that trigger an inflammatory response since during necrotic death the cell membrane is ruptured and the intracellular constituents including high mobility group box 1 (HMGB1) are released into the extracellular space, thereby activating an inflammatory response. In contrast, autophagic death is regarded as a form of tumour suppressive cell death, as indicated in tumour suppressors such as beclin 1 in autophagic pathways. To better understand the anti-inflammatory properties of sodium salicylate and its effect on necrotic cell death in A549 cells induced by glucose depletion (GD), a common characteristic of the tumour micro-environment, was examined. While GD induced mostly necrotic death in A549 cells, salicylate suppresssed GD-induced necrosis and HMGB1 release. In addition, salicylate shifted the cell death pattern to autophagy by inhibiting GD-induced Cu/Zn superoxide dismutase release and ROS production. These results indicate that the activity of salicylate to prevent necrotic death may contribute to its anti-inflammatory action and suppress tumour development possibly through switching the cell death mode from tumour-promoting necrotic cell death to tumour-suppressive autophagic cell death.

Expression of Fas ligand and sFas ligand in human gastric adenocarcinomas

This study was undertaken to determine whether human gastric adenocarcinoma expresses Fas-L, and whether serum sFas-L level changes in patients before and after gastrectomy, and whether Fas-L or sFas-L is related to tumor stage and histologic type. Retroactive analysis was performed in 38 cases of early gastric carcinoma (EGC) and 61 cases of advanced gastric carcinoma (AGC), including 38 cases of diffuse type and 61 cases of intestinal type, who underwent gastric resection from 1997 to 1998. Immunohistochemical staining for tumoral Fas-L detection and a sFas ligand ELISA kit for serum sFas-L detection were used. Fas-L was localized in neoplastic cells in 61% (23/38) of cases in the EGC group and 66% (40/61) of cases in the AGC group. The extent of Fas-L expression was variable, with both FasL-positive and -negative neoplastic regions occurring within a tumor. The mean serum sFas-L level was significantly higher in patients before treatment compared with that of controls, whereas the level in patients after gastrectomy was significantly lower as that of controls. Some patients whose preoperative serum sFas-L levels were within the normal limit expressed no tumoral Fas-L. Factors such as tumor stage, histologic subtype and other prognostic factors showed no correlation with Fas-L expression and serum sFas-L level. A statistically significant expression of tumoral Fas-L with concomitant increment of serum sFas-L in gastric adenocarcinoma was demonstrated. This finding suggested Fas-mediated apoptosis in response to Fas-L expression by gastric adenocarcinoma, providing evidence to support a Fas counterattack and indicated that the serum sFas-L level is a useful indicator in evaluating preoperative diagnosis and postoperative follow-up of gastric adenocarcinoma. The clinical stages of gastric adenocarcinoma of the intestinal and the diffuse type did not differ in their expression of Fas and sFas-L.

Clear Cell Adenocarcinoma Arising from Adenofibroma in a Patient with Endometriosis of the Ovary

Ovarian clear cell adenocarcinomas (CCACs) are frequently associated with endometriosis and, less often with clear cell adenofibromas (CCAFs). We encountered a case of ovarian CCAC arising from benign and borderline adenofibromas of the clear cell and endometrioid types with endometriosis in a 53-year-old woman. Regions of the adenofibromas showed transformation to CCAC and regions of the endometriosis showed atypical endometriotic cysts. This case demonstrates that CCAC can arise from CCAF or endometriosis.

Right side fixation of sigmoid colon with a hepato-sigmoidocolic fistula in patient with hepatocellular carcinoma and midgut malrotation

The location of the sigmoid colon varies within the abdominal cavity, but its mesocolon is fixed to the left side. Right side fixation of the sigmoid colon is a very rare congenital positional anomaly. In addition, it has been reported that hepatocolic fistula is also a very rare disease that may present lower gastrointestinal bleeding. Here, the authors describe a case of a 71-year-old man who underwent surgery for hepato-sigmoidocolic fistula complicated by hepatocellular carcinoma and the right side fixation of the sigmoid colon.

Ethyl pyruvate induces necrosis-to-apoptosis switch and inhibits high mobility group box protein 1 release in A549 lung adenocarcinoma cells

Ethyl pyruvate (EP), a stable lipophilic pyruvate derivative, has been shown to exert anti-inflammatory activities through inhibiting the expression of various pro-inflammatory mediators as well as circulating levels of high mobility group box protein 1 (HMGB1) in a variety of in vitro and in vivo model systems. Necrotic cell death triggers an inflammatory response through release of HMGB1 in the extracellular space due to the membrane rupture. In an effort to better understand the pharmacological action mechanism that could explain the anti-inflammatory properties of EP, we examined the effects of EP on necrotic cell death in A549 lung adenocarcinoma cells in response to glucose deprivation (GD), a common characteristic of the tumor microenvironment. Here we show that EP prevented GD-induced necrosis and HMGB1 release and switched the cell death mode to apoptosis through inhibiting GD-induced CuZn superoxide dismutase release and ROS production. These results suggest that the necrosis-to-apoptosis switch activity of EP may contribute to its anti-inflammatory action and that EP may suppress tumor development possibly through its activity to induce the cell death mode switch from tumor promoting necrotic cell death to tumor suppressive apoptotic cell death.

Inhibition of Dermatitis Development by Sopungsan in Nc/Nga Mice

Sopungsan (SS) is a traditional Korean decoction used for the treatment of dermatitis. The aim of this study is to confirm whether or not SS has a preventive effect on the development of atopic dermatitis in dinitrochlorobenzene-applied Nc/Nga mice. SS was administered orally to Nc/Nga mice, which led to the remarkable suppression of the development of dermatitis, as determined by a histological examination and the serum IgE levels. Moreover, SS inhibited the production of thymus- and activation-regulated chemokine (TARC) and its mRNA expression in a keratinocyte cell line, HaCaT, which had been stimulated with tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Activation of the nuclear factor-κB (NF-κB) or activator protein-1 (AP-1) is one of key steps in the signaling pathways mediating induction of TARC. In this study, SS selectively suppressed NF-κB activation which may be essential for TARC expression in TNF-α/IFN-γ treated keratinocytes. The inhibitory effect of SS on NF-κB activation and TARC production might be associated with the anti-dermatitic effects of SS.

Neuritis and gastrointestinal hemorrhage in scrub typhus patients

A 78-year-old woman with scrub typhus exhibited gastric hemorrhage with multiple gastric ulcers. This is the first report to confirm pathologically the presence of not only vasculitis but also, neuritis. The results suggest the necessity of studies confirming neuritis as the cause of gastric ulcer and bleeding in scrub typhus.

Synchronous Primary Anorectal Melanoma and Sigmoid Adenocarcinoma

A primary anorectal malignant melanoma is a rare tumor. Moreover, cases involving a synchronous anorectal melanoma and colon adenocarcinoma are extremely rare. The authors report a case of a synchronous anorectal melanoma and sigmoid adenocarcinoma in an 84-year-old man. The regions of the anorectal melanoma showed melanocytic nevi in the adjacent mucosa of the anal canal and rectum. A dysplastic nevus was also identified in the anal mucosa. This case demonstrates that an anorectal melanoma can arise from pre-existing anorectal melanocytic lesions.

Interpretation of Pin-1 and VEGF-C expression in breast infiltrating duct carcinoma

Pin-1 has been shown to regulate several phases of the cell cycle and is strikingly overexpressed in many human cancers. Vascular endothelial growth factor (VEGF)-C is a potent lymphangiogenic factor produced by tumor and stromal cells. However, little is known about the roles of Pin-1 and VEGF-C in breast carcinoma. p53 protein and cyclin D1 overexpressions have been shown to play a role as prognostic factors in many human cancers. To better understand the roles of Pin-1 and VEGF-C in breast carcinoma, we evaluated the immunohistochemical expression of Pin-1 and VEGF-C in relationship with p53 protein or cyclin D1 overexpression and clinicopathological parameters in 128 mammary infiltrating duct carcinomas. There was a positive expression in 100% of Pin-1, 88% of VEGF-C, 35% of p53 protein, and 66% of cyclin D1 in the breast carcinoma. Correlation of the positive expression of Pin-1 with tumor grade (p<0.01) and lymph node metastasis or cyclin D1 overexpression (p<0.05, respectively) was statistically significant. Significant correlation was observed between VEGF-C and tumor grade, lymph node metastasis or clinical stage (p<0.01, respectively). These results indicate that elevated Pin-1 or VEGF-C expression is more common in infiltrating duct carcinomas with poor prognostic characteristics and is partly associated with an unfavorable outcome. Given the role of cyclin D1 overexpression in oncogenesis of breast, these results suggest that overexpression of Pin-1 and VEGF-C may promote tumor progression and metastasis.

Prognostic implication of 15-hydroxyprostaglandin dehydrogenase down-regulation in patients with colorectal cancer

PURPOSE

Prostaglandin (PG) E2 is known to be closely related to cancer progression and is inactivated by 15-hydroxyprostaglandin dehydrogenase (PGDH). 15-PGDH is shown to have tumor suppressor activity and to be down-regulated in various cancers, including colorectal cancer (CRC). Therefore, we evaluated the expression of 15-PGDH and its prognostic effect in patients with CRC.

METHODS

15-PGDH expression was examined by using immunohistochemistry in 77 patients with CRC. Its prognostic significance was statistically evaluated.

RESULTS

Negative 15-PGDH expression was noted in 55.8% of the 77 cases of CRC. 15-PGDH expression showed no correlation with any of the various clinicopathologic parameters. The status of lymph node metastasis, tumor-node-metastasis stages, and pre-operative carcinoembryonic antigen levels showed significant prognostic effect. However, univariate analysis revealed down-regulation of 15-PGDH not to be a predictor of poor survival. The 5-year overall survival rate was 71.7% in the group with positive expression of 15-PGDH and 67.1% in the group with negative expression of 15-PGDH, but this difference was not statistically significant (P = 0.751).

CONCLUSION

15-PGDH was down-regulated in 55.8% of the colorectal cancer patients. However, down-regulation of 15-PGDH showed no prognostic value in patients with CRC. Further larger scale or prospective studies are needed to clarify the prognostic effect of 15-PGDH down-regulation in patients with colorectal cancer.

A comparative study of bone formation following grafting with different ratios of particle dentin and tricalcium phosphate combinations

This study aimed to evaluate the bone regeneration relative to tooth powder and tricalcium phosphate (TCP) mixing ratios using the rabbit cranium defect model. The tooth powder was mixed with TCP in 1:1, 3:1, and 1:3 ratios, and the different ratios were implanted in the rabbit cranium defect for 4 and 8 weeks. Powders crystal structure evaluated using scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and new bone formation (NBF) was analyzed using micro-computed tomography (CT) and histologic examination. NBF in the control group was restricted to the defect margins. More NBF was observed around the defect margins in the experimental groups compared with the control group. Specifically, active NBF was identified around the implant materials of the centrifugal part of the defect and defect margins in the 3:1 tooth powder: TCP group. Our results suggested that tooth powder and TCP may be useful in bone regeneration.

Histomorphometric analysis of delayed implantation after horizontal distraction osteogenesis of the mandible in dogs

PURPOSE

Insufficient alveolar width is known to impede successful implantation and is a major obstacle to successful oral reconstruction using intraosseous implants. The aim of this study was to evaluate the osseointegration at implantation after consolidation in distracted narrow alveolar bone.

MATERIALS

Three adult mongrel dogs weighing 9 to 10 kg were studied. The lower premolars were extracted and horizontal distraction was performed using a distraction device after 8 weeks. Eight weeks after consolidation period, SLA surface implants were installed. The dogs were killed after 4 weeks implantation.

RESULTS

The preoperative and postoperative buccolingual widths of alveolar ridge were 2.7 ± 2.1 mm and 4.8 ± 2.5 mm, respectively. Direct bone contact was achieved, with no significant difference in new bone formation observed between implants placed in the distracted and undistracted bone after 4 weeks.

CONCLUSIONS

It was concluded from this study that horizontal distraction is a useful technique in augmenting a narrow alveolar ridge necessary for implant placement.

Role of CDK8 and beta-catenin in colorectal adenocarcinoma

Colorectal adenocarcinoma is a major cause of morbidity and mortality. The Wnt/beta-catenin pathway plays an important role in colon cancers. However, relatively little is known about the regulatory mechanism of beta-catenin in colon cancers. CDK8 is a cyclin-dependent kinase (CDK) member of the mediator complex that couples transcriptional regulators to the basal transcriptional machinery, and is implicated in the transcriptional regulation of key pathways involved in colon cancers. To determine the relationship between CDK8 and beta-catenin expressions, a population-based study was conducted for immunohistochemical staining analysis of tumor tissues, and Western blot analysis and CDK8 interference studies of colon cancer cell lines. The hypothesis that colorectal cancers with CDK8 expression have distinct clinical, prognostic and molecular attributes was tested. Among 127 colorectal cancers, CDK8 expression was detected in 96 (76%) tumors by immunohistochemistry. CDK8 and beta-catenin expression had significant positive correlation with carcinogenesis, tumor progression and patient survival. Immunohistochemically, CDK8 expression in colorectal cancer was independently associated with beta-catenin activation (P=0.0002). However, beta-catenin expression was not completely suppressed by CDK8 interference in the colon cancer cell lines HCT-116, HT-29 and SNU-C5. These data support a potential link between CDK8 and beta-catenin, and suggest that CDK8 may identify a subset of colon cancer patients with a poor prognosis. However, control of CDK8 is not an effective therapeutic strategy through beta-catenin regulation of general colon cancer.

Correlation of cyclooxygenase-2 pathway and VEGF expression in head and neck squamous cell carcinoma

The purpose of this study was to determine whether cyclooxygenase-2 (COX-2) was overexpressed in head and neck squamous cell carcinoma (HNSCC) in relation to vascular endothelial growth factor (VEGF) expression and lymph node metastasis. COX-2 has an important role in the promotion of carcinogenesis, tumor invasiveness and angiogenesis. VEGF is a proangiogenic factor that is up-regulated in various tumors. VEGF has been shown to interact with COX-derived prostaglandins in angiogenesis. To better understand the roles of these genes in HNSCC, we evaluated the immunohistochemical expression pattern of COX-2 and VEGF in relationship with histologic differentiation, clinical stage, and nodal status in 146 HNSCC. The COX-2/VEGF double immunofluorescein staining was evaluated with confocal scanning laser microscope. A positive expression was seen in 96% (140/146: 98 strong positive, 42 weakly positive) for COX-2 and in 98% (143/146: 63 strong positive, 80 weakly positive) for VEGF in HNSCC. A correlation was present in the positive expression of COX-2 with histologic differentiation, clinical stage, and nodal status. VEGF expression was also correlated with nodal status. A significant relation was observed between COX-2 and VEGF expressions. The simultaneous expression of COX-2 and VEGF was statistically significant (p<0.05). These results indicate that elevated COX-2 or VEGF expression is more common in HNSCC with poor prognostic characteristics. The present findings support the efforts to initiate clinical trials on the efficacy of COX-2 inhibitors in adjuvant treatment of HNSCC.

Significance of E-cadherin/beta-catenin complex and cyclin D1 in breast cancer

E-cadherin and beta-catenin are important epithelial adhesion molecules in normal epithelium. Loss of E-cadherin - beta-catenin adhesion is an important step in the progression of many epithelial malignancies. beta-catenin plays also a role in intracellular signaling and can function as an oncogene when binds to the T-cell factor 4 (Tcf4)-binding site in the promotor region of cyclin D1 and transactivates genes after translocation to the nucleus. We evaluated the immunohistochemical expression pattern of E-cadherin, beta-catenin in relationship with cyclin D1 overexpression, tumor stage, clinicopathologic parameters and patient survival in 128 mammary infiltrating duct carcinomas. The expression of E-cadherin/beta-catenin complex and beta-catenin/cyclin D1 double staining with confocal scanning laser microscope was evaluated. There were aberrant expressions in 78% of E-cadherin, 79% of beta-catenin, and 66% of cyclin D1 in breast cancer. There was correlation of aberrant expression of E-cadherin or beta-catenin with lymph node metastasis, survival rate, and survival length. However, there was no correlation of cyclin D1 overexpression with aberrant expression of E-cadherin or beta-catenin. No death was found in normal expression of beta-catenin, however lowest survival (50%) was found in nuclear beta-catenin expression. There was correlation of overexpression of cyclin D1 with survival rate and survival length. The highest survival rate and survival length were found in membranous normal beta-catenin expression group, however significant decrement of survival length was found in the groups of aberrant expression one or both of E-cadherin or/and beta-catenin. These results suggest that aberrant expression of E-cadherin, beta-catenin, and cyclin D1 may be involved in tumor metastasis, and analysis of the degree or the pattern of E-cadherin, beta-catenin, cyclin D1, and E-cadherin/beta-catenin complex may be good prognostic markers of mammary infiltrating duct carcinoma.

Comparative Study on Osseointegration of Implants After Flap and Flapless Surgery in the Mandible of Dogs

PURPOSE

The objective of this study was to compare the implant stability and osseointegration of implants using a flap or flapless technique.

MATERIAL AND METHODS

Mandibular premolars and molars were extracted from both sides in 6 dogs. After 8 weeks, 4 fixtures were implanted using either a flap or flapless technique. Implant stability quotient was measured on insertion and at 2, 4, and 8 weeks later. The animals were killed while the tissues were histologically analyzed.

RESULTS

Implant stability increased for 8 weeks, and no statistically significant differences were observed between the surgical protocols. Bone-implant contact showed 60.27% ± 30.99% for flapless surgery and 59.73% ± 17.12% for flap surgery. And the results of new bone formation area from total area showed 56.07% ± 27.78% for flapless surgery and 57.00% ± 14.66% for flap surgery. There were no statistically significant differences.

CONCLUSION

This study showed no significant difference in implant stability as well as osseointegration regardless of flap or flapless technique.

Significance of p-STAT3 expression in human colorectal adenocarcinoma

To examine the relationship between p-STAT3 and the clinicopathological parameters of colorectal adenocarcinoma (CRA), we initially conducted immunohistochemical (IHC) analyses on formalin-fixed tissues. A total of 127 invasive CRA, 20 colorectal adenomas and 20 normal mucosae were obtained. To clarify the validity of p-STAT3 as determined by the IHC analysis, quantitative real-time PCR was performed on fresh samples from 51 CRA-4 carcinomas in situ, 47 invasive CRA and on 51 normal mucosae. IHC analyses were conducted after formalin fixation from 51 CRA for comparison. The statistically significant difference of immunoreactivity for p-STAT3 between the CRA and adenoma, and between the CRA and normal mucosae was identified. Among the 174 CRA, p-STAT3 immunoreactivity significantly correlated with the T- and clinical stage. Among the 47 invasive CRA, the expression of STAT3 as determined by real-time PCR significantly correlated with tumor size, M stage and clinical stage. The overall findings of the real-time PCR analyses correlated with the findings of the IHC analyses. These findings suggest that p-STAT3 expression has an important role related to the tumorigenesis and tumor progression of CRAs. Moreover, IHC analysis is a reliable and useful modality of assessing the status of p-STAT3 expression in formalin-fixed samples.

Loss of BRCA1 Spontaneously Induces the Tumorigenesis in Lacrimal Gland

Environmental and genetic factors exert important influences on lifespan and neoplastic transformation. We have previously shown that spontaneous tumors form frequently in mice homozygous for a full-length Brca1 deletion. In general, mutations of BRCA1 are closely associated with induction of breast and ovarian cancers but are also known to contribute to the incidence of other cancers at a low frequency. Female Brca1-mutant mice (Brca1co/coMMTV-cre) were generated by crossing Brca1 conditional knockout mice and MMTV-cre mice, and the occurrence of lacrimal gland abnormalities and tumors was followed until mice reached 18 months of age. Lacrimal gland tumors, which occur at a very low frequency in the human population (1 per 1,000,000 per year), were detected in 7 cases of Brca1co/coMMTV-cre mice (2.75%) older than 9 months of age. None of seven mice exhibited any abnormality in the mammary gland including neoplasia, suggesting lacrimal gland tumor is spontaneously and independently formed. These tumors, which were detected in seven mutant mice that displayed exophthalmoses, were malignant, originated from epithelial cells, and were identified as acinic cell carcinoma by pathological analysis. Further analysis revealed that tumorigenesis was accompanied by the accumulation of cyclin D1 and decreased expression of the cellular oncogenes, c-Myc, c-Jun, and c-Raf. Tumors also exhibited rearrangement of cytoskeletal proteins, including β-catenin, keratin 5, and vimentin, depending on tumor progression. These results suggest that BRCA1 is involved in genetic stability of the lacrimal gland, providing new insight into genomic instability in organism maintenance and tumorigenesis of the lacrimal gland.