Effect of airborne-particle abrasion and polishing on novel translucent zirconias: Surface morphology, phase transformation and insights into bonding.

PURPOSE: The purpose this study was to investigate the effect of Kern´s air-borne particle abrasion protocol (KAPA) and polishing on two translucent zirconias (4Y, 5Y-zirconias) compared to a traditional zirconia (3Y-zirconia). METHODS: Two different surface treatments were analysed by X-ray diffraction (XRD) and interferometry 1) KAPA (0.1 MPa, 50 µm alumina, 10-12 mm distance, 15 sec and 30 sec and cleaning in ultrasound using isopropyl alcohol 99%) and 2) Clinical-delivery polishing paste (Zircon Brite, Dental Ventures, USA). Shear-bond strength tests (SBS's) were performed with a highly polished and virtually flat surface in combination with a 10-MDP based cement and a surface modified by KAPA in combination with zinc phosphate cement. The SBS was expressed in terms of MPa. RESULTS: The mean values for monoclinic content were 13 wt%, 7 wt% and 2 wt% for 3Y-, 4Y- and 5Y-zirconias respectively, no differences were found between 15 and 30 seconds. Polishing did not result in phase transformation to monoclinic phase in any of the zirconias. The rhombohedral phase was identified in all types of zirconias regardless of surface treatment. Shear-bond strength tests showed 5 MPa for polished/10-MDP based cement and 3 MPa for KAPA/ Zinc phosphate. Statistically significant differences were found between the two different surface treatments but not between the types of zirconias. CONCLUSIONS: KAPA for 15 sec seems to be equal to 30 sec regarding morphology and phase transformation. Sole micro-retention appears not to be fully responsible for the bonding phenomena of 10-MDP and zirconia that underwent KAPA.

Proanthocyanidin-rich grape seed extract improves bone loss, bone healing, and implant osseointegration in ovariectomized animals.

The purpose of the present study was to confirm if proanthocyanidin-rich grape seed extract (GSE) had the ability to improve bone health such as bone loss, bone healing, and implant osseointegration (defined as the direct connection between bone tissue and an implant) in ovariectomized (OVX) animals. We demonstrated that daily oral administration of GSE prevented bone loss in the lumbar vertebrae and femur in OVX mice. In addition, osteoclastogenesis in the lumbar spine bone of OVX mice, as assessed by histological and histomorphometric analyses, was accelerated but GSE prevented this dynamization, suggesting that GSE could counteract OVX-induced accelerated osteoclastogenic activity. In rats, OVX clearly impaired the healing of defects created on the calvaria, and GSE overcame this OVX-impaired healing. In the same way, osseointegration of a tibial implant in rats was retarded by OVX, and GSE counteracted the OVX-induced poor osseointegration, likely promoting bone healing by preventing imbalanced bone turnover. These results suggest that orally administered GSE improved implant osseointegration by mitigating the impaired bone health induced by OVX as a model of estrogen deficiency.

Evaluation of supercritical fluid extraction for the determination of neonicotinoid pesticides in green onion.

A supercritical fluid extraction (SFE) method was presented for the determination of neonicotinoid pesticides in green onion. We optimized the SFE parameters, namely the pressure, temperature, type and concentration of the modifier solvent, and extraction time, by testing on the incurred green onion applied with four commercial neonicotinoid formulations at the harvesting stage. The analytical values of the four neonicotinoids, obtained by 5 min dynamic SFE with a 25% (v/v) methanol/supercritical carbon dioxide mixture at 80 °C and 25 MPa, were in good agreement with those obtained by solid-liquid extraction using a homogenizer. This latter homogenization method is employed as a Japanese official method for the analysis of pesticide residues in food. The SFE-to-homogenization analytical value ratios were in the range 98.8-100.0%. Spike-and-recovery testing with spiked green onion was also performed by optimized SFE. The ratios of the analytical-to-spiked concentrations for six neonicotinoids obtained by the SFE method were 96.1-102.1% for 0.4 mg/kg and 93.9-104.1% for 4.0 mg/kg spiking levels. These values satisfied the Japanese validation guidelines for the testing method of pesticides in food. These results indicate that SFE is applicable for the analysis of neonicotinoids in green onion and enables automatic extraction with a small amount of solvent.

Evaluation of pressurized liquid extraction for the determination of neonicotinoid pesticides in green onion.

A pressurized liquid extraction (PLE) method was presented for the determination of six neonicotinoid pesticides, acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam in green onion. The critical parameters of PLE, e.g. extraction solvent, temperature, pressure, number of cycles, and static extraction time, were optimized by test on the spiked green onion with six neonicotinoids and the incurred green onion applied with four commercial neonicotinoid insecticide formulations (acetamiprid, dinotefuran, imidacloprid, and thiamethoxam). As a result, the recoveries of six neonicotinoids obtained by one cycle PLE with acetonitrile at 140 °C and 50 bar for 10 min were 94.7-99.5%. These results were acceptable according to the validation guideline for testing method of agricultural chemicals in food by Ministry of Health, Labour, and Welfare in Japan. PLE was also validated by the test on the incurred green onion. The analytical values of four neonicotinoids obtained by PLE were good agreement with those obtained by solid-liquid extraction with homogenizer, which is employed for Japanese official method for the analysis of pesticide residues in food (the ratios of analytical values obtained by PLE to those obtained by solid-liquid extraction were 99.7-101.2%). These results indicate that PLE is applicable for the determination of neonicotinoids in green onion.

Evaluation of the impact of matrix effects in LC/MS measurement on the accurate quantification of neonicotinoid pesticides in food by isotope-dilution mass spectrometry.

The use of isotope-labeled internal standards is the most widely accepted approach to overcome the matrix effects on quantification of pesticides in food by LC/MS. We evaluated the impact of the matrix effects on quantification of six neonicotinoid pesticides, acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam, in food by using deuterated internal standards. The calibration curves for each pesticide were obtained by using matrix-free and matrix-matched calibration solutions with blank brown rice, carrot, and green onion extracts. For brown rice and carrot, the matrix effects were not observed. In contrast, the slopes of calibration curves for each pesticide were influenced by presence of green onion extracts in calibration solutions (variability of the slopes was 4-9%), because the ratios of peak area for native pesticide to those for internal standards were influenced by matrix. The spike-and-recovery test with green onion was also performed. The analytical values obtained by using matrix-free calibration solution were biased from the spiked concentration, whereas those obtained by using matrix-matched calibration solution were comparable to the spiked concentration. These results indicate that matrix-matched calibration solution should be used for accurate quantification of neonicotinoid pesticides in food by LC/MS using deuterated internal standards.

Hydroxyl radicals generated by hydrogen peroxide photolysis recondition biofilm-contaminated titanium surfaces for subsequent osteoblastic cell proliferation.

Titanium dental implants have been successfully used for decades; however, some implants are affected by peri-implantitis due to bacterial infection, resulting in loss of supporting bone. This study aimed to evaluate the effect of an antimicrobial chemotherapy employing H2O2 photolysis-developed to treat peri-implantitis-on biofilm-contaminated titanium surfaces in association with osteoblastic cell proliferation on the treated surface. Titanium discs were sandblasted and acid-etched, followed by contamination with a three-species biofilm composed of Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mitis. This biofilm model was used as a simplified model of clinical peri-implantitis biofilm. The discs were subjected to ultrasound scaling, followed by H2O2 photolysis, wherein 365-nm LED irradiation of the disc immersed in 3% H2O2 was performed for 5 min. We analysed proliferation of mouse osteoblastic cells (MC3T3-E1) cultured on the treated discs. Compared with intact discs, biofilm contamination lowered cell proliferation on the specimen surface, whereas H2O2 photolysis recovered cell proliferation. Thus, H2O2 photolysis can recover the degraded biocompatibility of biofilm-contaminated titanium surfaces and can potentially be utilised for peri-implantitis treatment. However, to verify the findings of this study in relation to clinical settings, assessment using a more clinically relevant multi-species biofilm model is necessary.

Involvement of an autotoxic compound in asparagus decline.

Asparagus (Asparagus officinalis L.) is a widely cultivated perennial veritable and can be harvested more than ten years. However, the crop quality and yield decline after a few year's cultivation, which is called "asparagus decline". Even though those asparagus plants were replaced with new young asparagus plants, the productivity and quality of the crop remain relatively low, which is known as a "asparagus replant problem". One of the possible reasons for "asparagus decline" and "asparagus replant problem" is thought to be autotoxicity of asparagus. However, the compounds involved in the autotoxicity is not clear. The objective of this study was therefore to determine the potential role of autotoxicity in the "asparagus decline" and "asparagus replant problem". An aqueous methanol extract of 10-year-asparagus-cultivated soils inhibited the growth of asparagus seedlings and other two test plants with concentration dependent manner. The result confirmed that the asparagus soils have autotoxic activity. The extract was then purified by several chromatographies with monitoring the inhibitory activity and a potent growth inhibitory substance causing the autotoxic effect was isolated. The chemical structures of the compound was determined by spectral data to be trans-cinnamic acid. trans-Cinnamic acid inhibited the growth of asparagus seedlings at concentrations greater than 10 µM. The concentrations required for 50% growth inhibition of asparagus (IC50) were 24.1-41.6 µM. trans-Cinnamic acid accumulated 174 µM in the 10-year-asparagus-cultivated soils, which may be enough levels to cause the growth inhibition on asparagus considering its IC50 value. Therefore, trans-cinnamic acid may contribute to the autotoxic effect of asparagus soils, and may be in part responsible for "asparagus decline" and "asparagus replant problem".

Efficacy and safety of a therapeutic apparatus using hydrogen peroxide photolysis to treat dental and periodontal infectious diseases.

The present study aimed to evaluate the acute locally injurious property of our most current hydroxyl radical generation system by hydrogen peroxide (H2O2) photolysis. This system, which releases 3% H2O2 with a 405-nm laser, was developed in our laboratory for the treatment of dental and periodontal infectious diseases. First, the hydroxyl radical yield generated by H2O2 photolysis was examined by applying an electron spin resonance-spin trapping technique. Second, the bactericidal effect of the device was examined under a simulant condition in which Streptococcus mutans, a pathogenic bacterial species that causes caries, was irrigated with running 3% H2O2 concomitantly with laser irradiation. Finally, the acute topical effect of the model apparatus on rat palatal mucosa was evaluated by histological examination. We found that the hydroxyl radical yield was dependent upon laser output power. The bacterial count was substantially reduced within as little as 3 min. No abnormal findings were observed in the palatal mucosa, even when rats received three treatments of 3% H2O2 with laser irradiation at an output power of 40 mW. These results suggest that our apparatus has the ability to kill bacteria via hydroxyl radical generation and is safe to use at the lesion site of dental and periodontal infectious diseases.

Cytoprotective effects of grape seed extract on human gingival fibroblasts in relation to its antioxidant potential.

Cytoprotective effects of short-term treatment with grape seed extract (GSE) upon human gingival fibroblasts (hGFs) were evaluated in relation to its antioxidant properties and compared with those of a water-soluble analog of vitamin E: trolox (Tx). GSE and Tx showed comparable antioxidant potential in vitro against di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH; a stable radical), hydroxyl radical (•OH), singlet oxygen (1O2), and hydrogen peroxide (H2O2). Pretreatment or concomitant treatment with GSE for 1 min protected hGFs from oxidative stressors, including H2O2, acid-electrolyzed water (AEW), and 1O2, and attenuated the intracellular formation of reactive oxygen species induced by H2O2 and AEW. Tx also reduced the H2O2- and AEW-induced intracellular formation of reactive oxygen species, but showed no cytoprotective effects on hGFs exposed to H2O2, AEW, or 1O2. These results suggest that the cytoprotective effects of GSE are likely exerted independently of its antioxidant potential.

Bactericidal Activity and Mechanism of Photoirradiated Polyphenols against Gram-Positive and -Negative Bacteria.

The bactericidal effect of various types of photoirradiated polyphenols against Gram-positive and -negative bacteria was evaluated in relation to the mode of action. Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus mutans) and Gram-negative bacteria (Aggregatibacter actinomycetemcomitans, Escherichia coli, and Pseudomonas aeruginosa) suspended in a 1 mg/mL polyphenol aqueous solution (caffeic acid, gallic acid, chlorogenic acid, epigallocatechin, epigallocatechin gallate, and proanthocyanidin) were exposed to LED light (wavelength, 400 nm; irradiance, 260 mW/cm(2)) for 5 or 10 min. Caffeic acid and chlorogenic acid exerted the highest bactericidal activity followed by gallic acid and proanthocyanidin against both Gram-positive and -negative bacteria. It was also demonstrated that the disinfection treatment induced oxidative damage of bacterial DNA, which suggests that polyphenols are incorporated into bacterial cells. The present study suggests that blue light irradiation of polyphenols could be a novel disinfection treatment.

Number of Lymph Nodes in Rectal Cancer is Correlated with Response to Preoperative Chemoradiotherapy but is not Associated with Patient Survival.

BACKGROUND/AIMS: We aimed to clarify the oncological significance of the number of lymph nodes in rectal cancers treated with preoperative chemoradiotherapy. METHODOLOGY: We studied 126 curatively operated patients with clinical T3-T4 and M0 rectal cancers. The number of lymph nodes and clinicopathological features were compared between the patients treated with surgery alone (OP group, n = 45) and those treated with preoperative chemoradiotherapy (50-50.4 Gy in 25-28 fractions with tegafur-uracil and leucovorin, CRT group, n = 81). Factors influencing lymph node count and its prognostic significance were analyzed. RESULTS: The CRT group had significantly fewer lymph nodes than the OP group (12.4 vs. 21.1, P < 0.0001). High histological regression of rectal lesions was significantly correlated with decreased lymph node count in the CRT group. In the OP group, the 5-year cancer-specific survival rate of the patients with 12 or more lymph nodes was significantly better than those with fewer than 12 lymph nodes (75.1% vs. 33.3%, P = 0.02); in the CRT group, on the other hand, these survival rates did not differ (84.5% vs. 77.5%, P = 0.6). CONCLUSIONS: The number of lymph nodes in rectal cancer was correlated with the response of primary rectal lesions to chemoradiotherapy, and was not associated with patient survival.

In vitro evaluation of the risk of inducing bacterial resistance to disinfection treatment with photolysis of hydrogen peroxide.

The purpose of the present study was to evaluate the risk of inducing bacterial resistance to disinfection treatment with photolysis of H2O2 and comparing this with existing antibacterial agents. We tested seven antibacterial agents, including amoxicillin, cefepime hydrochloride, erythromycin, ofloxacin, clindamycin hydrochloride, ciprofloxacin hydrochloride, and minocycline hydrochloride, as positive controls for validation of the assay protocol. For all of the agents tested, at least one of the four bacterial species (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Streptococcus salivarius) was resistant to these agents by repeated exposure to subinhibitory concentrations of the agents up to 10 times. In contrast, antibacterial activity against any of the bacterial species tested (S. aureus, E. faecalis, E. coli, S. salivarius, Pseudomonas aeruginosa, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans) was not affected by repeated exposure to the disinfection treatment up to 40 times. This finding suggested that the risk of inducing bacterial resistance by disinfection treatment was low. The active ingredient of this disinfection treatment is hydroxyl radicals generated by photolysis of H2O2. Therefore, hydroxyl radicals interact with several cell structures and different metabolic pathways in microbial cells, probably resulting in a lack of development of bacterial resistance. In conclusion, disinfection treatment with photolysis of H2O2 appears to be a potential alternative for existing antimicrobial agents in terms of a low risk of inducing bacterial resistance.

Bactericidal action of photogenerated singlet oxygen from photosensitizers used in plaque disclosing agents.

BACKGROUND: Photodynamic therapy (PDT) has been suggested as an efficient clinical approach for the treatment of dental plaque in the field of dental care. In PDT, once the photosensitizer is irradiated with light of a specific wavelength, it transfers the excitation energy to molecular oxygen, which gives rise to singlet oxygen. METHODOLOGY/PRINCIPAL FINDINGS: Since plaque disclosing agents usually contain photosensitizers such as rose bengal, erythrosine, and phloxine, they could be used for PTD upon photoactivation. The aim of the present study is to compare the ability of these three photosensitizers to produce singlet oxygen in relation to their bactericidal activity. The generation rates of singlet oxygen determined by applying an electron spin resonance technique were in the order phloxine > erythrosine ≒ rose bengal. On the other hand, rose bengal showed the highest bactericidal activity against Streptococcus mutans, a major causative pathogen of caries, followed by erythrosine and phloxine, both of which showed activity similar to each other. One of the reasons for the discrepancy between the singlet oxygen generating ability and bactericidal activity was the incorporation efficiency of the photosensitizers into the bacterial cells. The incorporation rate of rose bengal was the highest among the three photosensitizers examined in the present study, likely leading to the highest bactericidal activity. Meanwhile, the addition of L-histidine, a singlet oxygen quencher, cancelled the bactericidal activity of any of the three photoactivated photosensitizers, proving that singlet oxygen was responsible for the bactericidal action. CONCLUSIONS: It is strongly suggested that rose bengal is a suitable photosensitizer for the plaque disclosing agents as compared to the other two photosensitizers, phloxine and erythrosine, when used for PDT.

A case report of thyroid gland metastasis associated with lung metastasis from colon cancer.

Thyroid gland metastasis of malignant tumors is observed in 1.9% to 9.5% of histologically examined autopsy cases. Thyroid metastasis from colon cancer is extremely rare and the prognosis is poor. Here we report a case of lung metastasis and thyroid gland metastasis following sigmoid colon cancer surgery. In 2000, a 58-year-old woman underwent a sigmoid colectomy for sigmoid colon cancer. In 2005, a metastatic lung tumor was detected by chest CT. The patient underwent a partial thoracoscopic resection of the left lung in April 2005. On a CT scan taken 3 years and 4 months after the lung resection, a tumor mass was observed in the left lung and a low-absorption region with an unclear border was seen in the left lobe of the thyroid gland. Thyroid aspiration cytology showed adenocarcinoma, and a diagnosis of thyroid gland metastasis from sigmoid colon cancer was made. In April 2008 a subtotal thyroidectomy was performed. Following surgery, the patient underwent chemotherapy with mFOLFOX6 and bevacizumab. Nevertheless a number of lung metastases and expressions of lung metastasis were subsequently observed. Histopathological examination revealed a number of metastases of differentiated papillary adenocarcinoma in the thyroid gland from colon cancer.

A case of appendiceal Crohn's disease in which a laparoscopic appendectomy was performed.

A 74-year-old female had occasionally experienced right lower abdominal pain in the past. She underwent a barium enema examination during a medical checkup, which revealed a wall irregularity around the appendix, but the appendix itself was not visualized. The patient was referred to our hospital for possible appendiceal neoplasm. Colonoscopy revealed a tumor-like protrusion with marked redness at the entrance to the appendix. Pathologic analysis of biopsy specimens revealed only inflammatory cells. Differential diagnosis of appendiceal Crohn's disease or appendiceal neoplasm was made, and laparoscopic appendectomy was performed. Pathologic examination revealed inflammation in all layers of the appendiceal wall and noncaseating epithelioid cell granuloma, and a diagnosis of appendiceal Crohn's disease was made. The postoperative course was uneventful, and the patient was discharged from the hospital 3 days after surgery. No sign of recurrence has been observed up to now, 6 months after surgical treatment.