The role of nitric oxide in orthodontic tooth movement in rats

Nitric oxide (NO) is involved in second messenger formation, osteoblast and osteoclast function, and pulpal blood flow. This raises the question of whether or not altered NO production interferes with orthodontic tooth movement (OTM) by influencing the bone remodeling cycle. To investigate the role of NO in OTM, a rat model was established and 48 rats were divided into four study groups of 12 rats each. A 5 mm nickel-titanium closed-coil spring was ligated between the right maxillary incisor and first molar of each rat to deliver an initial force of 60 g. A saline group received subperiosteal injections of normal saline (50 microL/kg), an L-arginine (L-arg) group received L-arginine (NO precursor) injections (200 mg/kg), and a, L-NAME group received N(G)-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor)(10 mg/kg) injections. All injections were given in the upper right first molar mucosa from the first through the 11th day of force application at 48-hour intervals. A control group received no injections. Tooth movement measurements were done at the time of injections. Animals were sacrificed 13 days after appliance insertion and final OTMs were measured at the time of sacrifice. From the third day till the end of the experiment, the L-arg group showed a significant increase in tooth movements, whereas the L-NAME group showed a significant decrease in tooth movements compared to the control and saline group (P < .001). Histopathologic studies revealed that the number of osteoclasts was significantly higher in the L-arg group smears, while the number of osteoclasts in the L-NAME group was significantly lower as compared to the control group (P < .001). Scanning electron microscope analysis showed that the force-induced root resorption in the L-arg group was less than the control group. This study suggests a role for NO in the bone remodeling cycle.     

Microtensile bond strength testing of luting cements to prefabricated CAD/CAM ceramic and composite blocks.

OBJECTIVES: To investigate the Microtensile bond strength (microTBS) and failure mode of resin cements bonded to composite and ceramic CAD/CAM blocks following various surface treatments. METHODS: Paradigm composite blocks and Cerec Vitablocs received three surface treatments following the control treatment of surface grinding with 600 SiC grit. (1) Application of adhesive resin (Adh), (2) etching with hydrofluoric acid and silanization (HF+S) or (3) combination of the previous two treatments (HF+S+Adh). Three resin cements (Tetric Flow, Nexus 2, RelyX ARC) were applied to these surfaces and built-up in layers. After 24 h water storage at 37 degrees C, the non-trimming version of microTBS test was used to produce 1 mm(2) microbars. The Microbars were subjected to a tensile load using a modified testing device. The broken specimens were examined with a stereomicroscope and SEM to determine the failure mode. RESULTS: All control and adhesive treated groups of the ceramic substrate showed premature debonding during cutting. The overall mean microTBS for the three resin cements bonded to ceramic following HF+S and HF+S+Adh surface treatment, was 27 and 29.2 MPa and for the resin cements bonded to composite substrate was 42.3 and 54.2 MPa, respectively. The mode of failure was 98% adhesive with composite as a substrate and 68% mixed failures with ceramic as a substrate. CLINICAL SIGNIFICANCE: CAD/CAM restorations fabricated from processed composite blocks may have advantage over the ceramic blocks with regard to the higher bond strength with resin cements.     

Spatial and statistical analyses of the relations between vegetation cover and incidence of cutaneous leishmaniasis in an endemic province,northeast of Iran

Objective

To investigate the relations between the vegetation cover and occurrence of cutaneous leishmaniasis (CL) in Golestan province during 2010-2012.

Methods

Data of monthly CL incidence and remote sensing normalized difference vegetation index (NDVI) of moderate resolution imaging spectroradiometer sensor were used in the study. Pearson''s correlation analysis was conducted to examine the type and strength of relationships between the spatially averaged NDVI variables (i.e. minimum, maximum and mean NDVI values) and CL incidence in township level. Spearman rank correlation was carried out to explain associations between the monthly CL incidence and NDVI variables at 0, 1, 2, 3 and 4 months lagged periods. Locations of CL cases at village level were geocoded and compared with frequency of CL cases in each NDVI-derived vegetation categories.

Results

Pearson''s analysis revealed significant associations between the NDVI variables and CL incidence at the township level (P<0.05). Results of Spearman analysis indicated that the highest correlations between NDVI variables and monthly CL incidence were established when the NDVI time-series lagged the CL incidence series NDVI variables. Purely spatial analysis demonstrated that despite majority of cases occurred at partially-vegetated areas, the possibility of CL occurrence was higher in bare soil areas by taking into account area of each vegetation zones.

Conclusions

lack or low vegetation cover is a major determinant of CL frequencies in Golestan province. The decrease of the mean vegetation density in townships is accompanied by increase of CL occurrence and vice versa.     

Blood bezoar causing obstruction after laparoscopic Roux-en-Y gastric bypass

INTRODUCTION

Bowel obstruction is a known complication after bariatric surgery especially Roux-en-Y gastric bypass. The known etiologies include internal hernia, jejunojejunostomy stricture, ileus, intussusceptions, superior mesenteric artery syndrome, incarcerated port site hernia, and adhesions. Blood bezoar is a rare cause of small intestinal obstruction after Roux-en-Y gastric bypass.

PRESENTATION OF CASE

We are going to present two cases of small bowel obstruction after Roux-en-Y gastric bypass due to blood bezoar.

DISCUSSION

Blood clot as the etiology of small bowel obstruction after Roux-en-Y gastric bypass is an unusual event. In the presence of postoperative small intestinal obstruction an obstructive blood bezoar should be in differential diagnosis. As any other etiology of postoperative obstruction it should be treated immediately to prevent its adverse lethal complications.

CONCLUSION

The best way for prevention of blood bezoar is prevention of bleeding at staple line and doing hemostasis at stapler line.     

The Effects of Curcumin and Curcumin–Phospholipid Complex on the Serum Pro‐oxidant–Antioxidant Balance in Subjects with Metabolic Syndrome

Metabolic syndrome (MetS) is defined by a clustering of metabolic and anthropometric abnormalities and is associated by an increased risk of cardiovascular disease. We have investigated the effect of curcumin supplementation on the serum pro‐oxidant–antioxidant balance (PAB) in patients with MetS. This double‐blind, randomized, placebo‐controlled trial was conducted over 6 weeks. Subjects (n = 120) were randomly allocated to one of three groups (curcumin, phospholipidated curcumin, and placebo). The curcumin group received 1 g/day of simple curcumin, the phospholipidated curcumin group received 1 g/day of phospholipidated curcumin (containing 200 mg of pure curcumin), and the control group received 1 g/day of placebo. Serum PAB was measured before and after the intervention (at baseline and at 6 weeks). Data analyses were performed using spss software (version 16.0). Serum PAB increased significantly in the curcumin group (p < 0.001), but in the phospholipidated curcumin group, elevation of PAB level was not significant (p = 0.053). The results of our study did not suggest any improvement of PAB following supplementation with curcumin in MetS subjects. Copyright © 2017 John Wiley & Sons, Ltd.     

Assessing the 16 hour intern shift limit: Results of a multi-center,mixed-methods study of residents and faculty in general surgery

Background

The study explores how residents and faculty assess the ACGME's 16-h limit on intern shifts.