Involvement of nitric oxide in orthodontic tooth movement in rats.

Nitric oxide (NO) is an important regulatory molecule in bone formation and resorption. The purpose of this study was to examine the role of NO in orthodontic tooth movement in rats. We used specific inhibitors of NO synthases (NOS). Upper first molars of 9-week-old male Wistar rats were moved buccally for 21 days. The local administration of N(G)-nitro-L-arginine methyl ester. HCl (L-NAME), a general inhibitor of NOS activity, significantly reduced tooth movement. On the other hand, N(6)-(1-iminoethyl)-L-lysine. 2HCl (L-NIL), a selective inhibitor of the inducible isoform of NOS, had no effect. These results suggest that NO is an important biochemical mediator in the response of periodontal tissue to orthodontic force and is produced primarily through the activity of constitutive NOS.     

Temporomandibular joint and masticatory muscle involvement in myotonic dystrophy: a study by magnetic resonance imaging

OBJECTIVE: The purpose of this study was to evaluate the masticatory muscles and the temporomandibular joint (TMJ) by magnetic resonance imaging (MRI) in myotonic dystrophy (MD) patients. STUDY DESIGN: MRI of the masticatory muscles and TMJ was performed in 15 MD patients, 11 male and 4 female, aged 16 to 53 years (mean, 31 years). Many of them had dental malocclusion, especially Angle class III and anterior open bite, and 3 complained of recurrent TMJ dislocation. TMJ and masticatory muscle pain was not observed, and joint sounds were noted in only 1 patient. RESULTS: The analysis of MRI scans showed masticatory muscle involvement in 13 patients (86.6%). In 11, the involvement was moderate to intense. The main abnormalities observed were increased intramuscular tissue signal on T1 (fatty infiltration) and volumetric reduction of muscles. Regarding the TMJ, articular disk displacement was seen in only 1 patient, but abnormalities of disk shape were common. Mild bone abnormalities were frequently observed, including changes of shape and contour of bone surface, and sclerosis of bone marrow. In 4 patients the condyle moved anterior to the eminence with the mouth opened fully (condylar hyperexcursion). CONCLUSIONS: This study shows that masticatory muscles are frequently and intensively affected in MD patients. Bone changes are the most consistent abnormalities observed in the TMJ. It is possible that remodeling is caused by biomechanical changes in the jaw as a result of masticatory muscle involvement.     

Assessment of in vitro interleukin-2-producing capacity of peripheral blood lymphocytes from patients with periodontitis.

Abstract In this cross-sectional study, we assessed the in vitro interleukin-2 (IL-2) producing capacity of peripheral blood mononuclear cells (PBMC) and lymphocytes from patients with different forms of periodontitis. 45 patients (12 with localised early onset periodontitis (LEOP), 20 with generalised early onset periodontitis (GEOP), and 13 with adult periodontitis (AP), and 20 periodontally healthy subjects (HS), participated in this study. PBMC and lymphocytes were isolated from the subjects and their cells were stimulated with an anti-CD3 monoclonal antibody (anti-CD3 MoAb) and the secreted IL-2 levels in the culture were bioassayed. No significant differences could be found in IL-2 producing activity of PBMC between the patients and HS group. There was wide interindividual variation and high and low “IL-2 producers” were noted. We found a LEOP patient who was a high producer of IL-2 (>mean+8 SD) and 2 LEOP patients and a HS who were low producers of IL-2 (相似文献   

Development of casting investment preventing blackening of noble metal alloys part 1. Application of developed investment for Ag-Pd-Cu-Au alloy

The objective of this study is to develop a casting investment that prevents the blackening of the cast surface of noble metal alloys. The experimental investments were prepared using a gypsum-bonded investment in which the metallic powders such as boron (B), silicon (Si), aluminum (Al) and titanium (Ti) were added as oxidizing agents. An Ag-Pd-Cu-Au alloy was cast into the mold made of the prepared investment. The effect of the addition of each metal powder was evaluated from the color difference between the as-cast surface and the polished surface of the cast specimen. The color of the as-cast surface approached that of the polished surface with increasing B and Al content. A lower mean value in the color difference was obtained at 0.25-1.00 mass% B content. B and Al are useful as an additive in a gypsum-bonded investment to prevent the blackening of an Ag-Pd-Cu-Au alloy. The effects of Si and Ti powder addition could not be found.     

Depth of cure and hardness of an indirect composite polymerized with three laboratory curing units

This study determined the hardness and curing depth of a light-activated indirect composite polymerized with three laboratory light-polymerizing units for the purpose of comparing the curing performance of the three units. A light-activated composite material for indirect application (Vita Zeta) was polymerized with three light-polymerizing units equipped with the following light sources: 1) one halogen lamp and two fluorescent lamps (alpha-Light II); 2) three halogen lamps (Twinkle HLG); and 3) one metal halide lamp (Twinkle LI). Knoop hardness and curing depth were determined for groups of five specimens using standardized testing methods. The results were compared using analysis of variance (ANOVA) and Scheffé's S intervals (alpha = 0.05). The Knoop hardness number (KHN) generated with the halogen-fluorescent unit (12.5 KHN) was significantly (P < 0.05) lower than those produced by the halogen unit (13.9 KHN) and the metal halide unit (14.2 KHN). Of the three units, the halogen-fluorescent unit exhibited the lowest depth of cure. Both the hardness and curing depth of the composite were influenced by the laboratory polymerizing units employed.     

Effect of single-liquid priming agents on adhesive bonding to aluminum oxide of a methacrylic resin

The purpose of this study was to evaluate the effects of acidic primers on adhesive bonding to sintered aluminum oxide (alumina). Alumina disks were primed with one of the following materials: Acryl Bond, All Bond 2 Primer B, Alloy Primer, Estenia Opaque Primer, Eye Sight Opaque Primer, M.L. Primer, MR. Bond, and Super-Bond Liquid. Specimens were then bonded with an acrylic resin initiated with partially oxidized tri-n-butylborane (TBBO), and bond strengths were determined. Unprimed specimen was employed as the control. Average bond strength before thermocycling ranged from 20.5 to 41.9 MPa, whereas post-thermocycling bond strength ranged from 0.0 to 40.0 MPa. Of the eight primers, Estenia Opaque Primer and Alloy Primer showed better adhesive performance than the other materials. It could thus be concluded that either Estenia Opaque Primer or Alloy Primer--which contained an adhesive monomer, 10-methacryloyloxydecyl dihydrogen phosphate (MDP)--was recommended for bonding alumina with TBBO-initiated resin.     

Evaluation of QOL After Proximal Gastrectomy Using a Newly Developed Assessment Scale (PGSAS-45)

Background

Proximal gastrectomy with esophagogastrostomy (PGEG) has been widely applied as a comparatively simple method. In this study, we used a questionnaire survey to evaluate the influence of various surgical factors on post-operative quality of life (QOL) after PGEG.

Methods

In this post-gastrectomy syndrome assessment study, we analyzed QOL in 2,368 cases. Among these, 193 had undergone proximal gastrectomy and 115 had undergone PGEG. The Post-Gastrectomy Syndrome Assessment Scale (PGSAS)-45 is a questionnaire consisting of 45 items, including the SF-8, the Gastrointestinal Symptom Rating Scale (GSRS), and other symptom items seemed to be specific to post-gastrectomy. The 23 symptom items were composed of seven symptom subscales (SS), including esophageal reflux, abdominal pain, and meal-related distress. These seven SS, total symptom score, ingested amount of food per meal, necessity for additional meals, quality of ingestion SS, ability to work, dissatisfaction with symptoms, dissatisfaction with the meal, dissatisfaction with working, dissatisfaction with daily life SS and change in body weight were evaluated as main outcome measures. In PGEG cases, we evaluated the influence on QOL of various surgical factors, such as procedures to prevent gastroesophageal regurgitation and size of the remnant stomach.

Results

The scores for esophageal reflux and dissatisfaction with the meal were higher in patients who had not undergone an anti-reflux procedure. In most cases, the preserved remnant stomach was more than two-thirds the size of the pre-operative stomach. When comparing patients with a remnant stomach two-thirds the pre-operative size and those with more than three-quarters, the diarrhea SS and necessity for additional meals scores were lower in the group with more than three-quarters. The indigestion, constipation, and abdominal pain subscales, and the total symptom score, were higher in patients who had not undergone pyloric bougie than in those who had.

Conclusion

These results indicated that QOL was better in patients with a large remnant stomach. Procedures to prevent gastroesophageal reflux, and the use of pyloric bougie as a complementary drainage procedure, were considered effective ways to reduce the deterioration of QOL.     

Trabecular Bone Score (TBS) Predicts Vertebral Fractures in Japanese Women Over 10 Years Independently of Bone Density and Prevalent Vertebral Deformity: The Japanese Population‐Based Osteoporosis (JPOS) Cohort Study

Bone strength is predominantly determined by bone density, but bone microarchitecture also plays an important role. We examined whether trabecular bone score (TBS) predicts the risk of vertebral fractures in a Japanese female cohort. Of 1950 randomly selected women aged 15 to 79 years, we analyzed data from 665 women aged 50 years and older, who completed the baseline study and at least one follow‐up survey over 10 years, and who had no conditions affecting bone metabolism. Each survey included spinal imaging by dual‐energy X‐ray absorptiometry (DXA) for vertebral fracture assessment and spine areal bone mineral density (aBMD) measurement. TBS was obtained from spine DXA scans archived in the baseline study. Incident vertebral fracture was determined when vertebral height was reduced by 20% or more and satisfied McCloskey‐Kanis criteria or Genant's grade 2 fracture at follow‐up. Among eligible women (mean age 64.1 ± 8.1 years), 92 suffered incident vertebral fractures (16.7/10³ person‐years). These women were older with lower aBMD and TBS values relative to those without fractures. The unadjusted odds ratio of vertebral fractures for one standard deviation decrease in TBS was 1.98 (95% confidence interval [CI] 1.56, 2.51) and remained significant (1.64, 95% CI 1.25, 2.15) after adjusting for aBMD. The area under the receiver operating characteristic curve of TBS and aBMD combined was 0.700 for vertebral fracture prediction and was not significantly greater than that of aBMD alone (0.673). However, reclassification improvement measures indicated that TBS and aBMD combined significantly improved risk prediction accuracy compared with aBMD alone. Further inclusion of age and prevalent vertebral deformity in the model improved vertebral fracture prediction, and TBS remained significant in the model. Thus, lower TBS was associated with higher risk of vertebral fracture over 10 years independently of aBMD and clinical risk factors including prevalent vertebral deformity. TBS could effectively improve fracture risk assessment in clinical settings. © 2014 American Society for Bone and Mineral Research.