Maxillary Anterior Teeth With Extensive Root Resorption Treated With Low-level Light-activated Engineered Chitosan Nanoparticles

IntroductionPhotoactivated chitosan-based nanoparticles can eliminate bacterial biofilm, inactivate endotoxins, improve resistance to biological degradation (resorption), and promote bone regeneration. This case is the first documentation to highlight the successful healing of teeth with extensive inflammatory root resorption (IRR) with periapical lesions using a combined surgical and nonsurgical root canal therapy using rose bengal functionalized chitosan nanoparticles (CSRBnp).MethodsA 17-year-old boy with extensive IRR of maxillary right canine (teeth #6), maxillary right lateral incisor (#7), maxillary right central incisor (#8), and maxillary left central incisor (#9) was treated with photoactivated CSRBnp, both intracanal as well as topically on resorptive defects and periapical lesions. The larger external resorptive defects on the root surfaces were restored with Biodentine, whereas the through-and-through periapical lesions were packed with sticky bone for Guided Bone Regeneration.ResultsAt 26 months of follow-up, the clinical, 2-dimensional (intraoral periapical radiographs) and 3-dimensional (cone-beam computed tomography) images showed absence of clinical symptoms, teeth mobility, arrested IRR, and significant osseous healing of the periradicular region. Postoperatively, the patient retraumatized thrice in relation to #7 resulting in horizontal root fracture, which showed type I pattern of root fracture healing in the follow-up.ConclusionsPhotoactivated chitosan-based nanoparticles can be a viable therapeutic option to hinder root resorption while enhancing healing outcomes in cases of severe IRR.     

Evaluating the image quality of cone beam CT acquired during rotational delivery

Objective:

The aim of this work was to evaluate the quality of kilovoltage (kV) cone beam CT (CBCT) images acquired during arc delivery.

Methods:

Arc plans were delivered on a Catphan^® 600 phantom (The Phantom Laboratory Inc., Salem, NY), and kV CBCT images were acquired during the treatment. The megavoltage (MV) scatter effect on kV CBCT image quality was evaluated using parameters such as Hounsfield unit (HU) accuracy, spatial resolution, contrast-to-noise ratio (CNR) and spatial non-uniformity (SNU). These CBCT images were compared with reference scans acquired with the same acquisition parameters without MV “beam on”. This evaluation was carried out for different photon beams (6 and 15 MV), arc types (half vs full arc), static field sizes (10 × 10 and 25 × 25 cm²) and source-to-imager distances (SID) (150 and 170 cm).

Results and Conclusion:

HU accuracy, CNR and SNU were considerably affected by MV scatter, and this effect was increased with increasing field size and decreasing photon energy, whereas the spatial resolution was almost unchanged. The MV scatter effect was observed to be more for full-rotation arc delivery than for half-arc delivery. In addition, increasing the SID resulted in decreased MV scatter effect and improved the image quality.

Advances in knowledge:

Nowadays, volumetric modulated arc therapy (VMAT) is increasingly used in clinics, and this arc therapy enables us to acquire CBCT imaging simultaneously. But, the main issue of concurrent imaging is the “MV scatter” effect on CBCT imaging. This study aims to experimentally quantify the effect of MV scatter on CBCT image quality.     

Modulation of xenobiotic-metabolizing enzymes by ethanolic neem leaf extract during hamster buccal pouch carcinogenesis

Chemoprevention by medicinal plants is a promising approach for controlling cancer. There is substantial evidence to indicate that chemopreventive agents exert their anticarcinogenic effects by modulation of phase I and phase II xenobiotic-metabolizing enzymes. Therefore, we examined the chemopreventive potential of ethanolic neem leaf extract (ENLE) on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Hamsters were divided into four groups of six animals each. The right buccal pouches of animals in Group I were painted with 0.5 per cent DMBA in liquid paraffin three times per week. Animals in Group 2 painted with DMBA as in group 1, received in addition, intragastric administration of ENLE at a concentration of 200 mg/kg bw three times per week on days alternate to DMBA application. Group 3 was given ENLE alone. Animals in Group 4 served as controls. All animals were killed after an experimental period of 14 weeks. Five out of six hamsters painted with DMBA alone developed squamous cell carcinomas in the buccal pouch. The HBP tumours showed an increase in phase I carcinogen activation (cytochrome P450 and b5) and phase II detoxification enzyme (glutathione-S-transferase, DT-diaphorase and NADPH-diaphorase) activities. In the liver of tumour-bearing animals, enhanced cytochrome P450 and b5 levels were accompanied by a decrease in phase II detoxification enzyme activities. Administration of ENLE effectively suppressed DMBA-induced HBP tumours, decreased cytochrome P450 and b5 levels, and enhanced phase II enzyme activities in the pouch and liver. Our results suggest that the modulation of DMBA metabolism is a possible mechanism for the chemopreventive effects of ethanolic neem leaf extract.     

Effects of aqueous extracts of garlic (Allium sativum) and neem (Azadirachta indica) leaf on hepatic and blood oxidant-antioxidant status during experimental gastric carcinogenesis

The modifying effects of aqueous extracts of garlic and neem leaf during the pre-initiation and post-initiation phases of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in male Wistar rats. The extent of lipid peroxidation and the status of phase II biotransformation enzymes such as glutathione peroxidase and glutathione-S-transferase that use reduced glutathione (GSH) as substrate were used to biomonitor the chemopreventive potential of these extracts. Enhanced lipid peroxidation in the liver and blood of tumor-bearing animals was accompanied by significant decreases in the activities of GSH-dependent antioxidants in the pre-initiation as well as in the post-initiation phases. Our results suggest that the modulatory effects of garlic and neem leaf on hepatic and blood oxidant-antioxidant status may play a key role in preventing cancer development at extrahepatic sites.     

Effect of S-allylcysteine on oxidant-antioxidant status during N-methyl-N'-nitro-N-nitrosoguanidine and saturated sodium chloride-induced gastric carcinogenesis in Wistar rats

We investigated the chemopreventive effect of S-allylcysteine (SAC), a water-soluble garlic constituent against gastric carcinogenesis induced in male Wistar rats by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and saturated sodium chloride (S-NaCl). The animals were divided into four groups of six animals. Rats in groups 1 and 2 were administered MNNG (200 mg/kg body weight) on days 0 and 14 as well as S-NaCl (1 mL/rat) three days during weeks 0 to 3, and thereafter placed on basal diet until the end of the experiment. Rats in group 2 in addition received SAC (200 mg/kg body weight) three times per week starting on the day following the first exposure to MNNG and continued until the end of the experimental period. Group 3 animals were given SAC alone as in group 2. Group 4 animals received basal diet and tap water throughout the experiment and served as the untreated control. The animals were sacrificed after an experimental period of 21 weeks. Measurement of lipid peroxidation and antioxidants of the glutathione redox cycle in the stomach tissue, liver and venous blood was used to monitor the chemopreventive potential of SAC. All animals that received MNNG and S-NaCl alone, developed tumours, identified histologically as squamous cell carcinomas. In the tumour tissue, diminished lipid peroxidation was accompanied by increase in reduced glutathione (GSH) and GSH-dependent enzymes, whereas in the liver and circulation, enhanced lipid peroxidation was associated with antioxidant depletion. Administration of SAC suppressed the incidence of MNNG+S-NaCl-induced gastric tumours as revealed by the absence of carcinomas. SAC ameliorated MNNG-induced decreased susceptibility of the gastric mucosa to lipid peroxidation, whilst simultaneously increasing the antioxidant status. In the liver and blood, SAC reduced the extent of lipid peroxidation and significantly enhanced antioxidant activities. We suggest that SAC exerts its chemopreventive effects by modulating lipid peroxidation and enhancing GSH-dependent antioxidants in the target organ as well as in the liver and blood.     

Oxidized low-density lipoprotein and intimal medial thickness in subjects with glucose intolerance: the Chennai Urban Rural Epidemiology Study-25

The aim of the present study was to assess the association of oxidized low-density lipoprotein (OX-LDL) with carotid intimal medial thickness (IMT) in different grades of glucose intolerance in Asian Indians. Three groups were recruited from the Chennai Urban Rural Epidemiology Study, a population-based study: group 1, normal glucose tolerance (NGT) (n = 175); group 2, impaired glucose tolerance (IGT) (n = 175); and group 3, type 2 diabetes mellitus (n = 175). Oxidized LDL (enzyme-linked immunosorbent assay) and carotid IMT (high-resolution B-mode ultrasonography) were assessed. Subjects with diabetes had higher IMT values (0.85 +/- 0.30 mm) compared with those who have IGT (0.79 +/- 0.16 mm, P < .05) and NGT (0.71 +/- 0.12 mm, P < .001). Subjects with diabetes (40.1 +/- 13.1 U/L) and IGT (34.3 +/- 12.8 U/L) had significantly higher mean OX-LDL values compared with the NGT group (26.2 +/- 16.6 U/L, P < .001). Oxidized LDL showed a correlation with IMT (total population: r = 0.294, P < .001; subjects with NGT: r = 0.444, P < .001; and subjects with IGT: r = 0.481, P < .001). In multiple linear regression analysis, OX-LDL showed a strong association with IMT (beta = .005, P < .001), even after adjusting for age, sex (beta = .003, P < .001), and glucose intolerance (beta = .002, P < .001). In conclusion, OX-LDL levels increase with increasing glucose intolerance. Oxidized LDL is associated with carotid IMT and this is independent of age, sex, and glucose intolerance status.     

Serum visfatin in relation to visceral fat, obesity, and type 2 diabetes mellitus in Asian Indians

To investigate the role of the novel adipokine visfatin in type 2 diabetes mellitus and obesity and to examine its association with visceral and subcutaneous fat in Asian Indians, who have increased susceptibility to type 2 diabetes mellitus and coronary artery disease, 150 subjects with type 2 diabetes mellitus (75 men, 75 women) and 150 age- and sex-matched subjects with normal glucose tolerance were recruited from the Chennai Urban Rural Epidemiology Study, a population-based study done in Chennai, southern India. Anthropometric and biochemical measurements were done by using standardized techniques. Fasting serum visfatin levels were measured by enzyme-linked immunosorbent assay. Visceral and subcutaneous fat were measured by computerized tomography in a subset of 130 individuals. Serum visfatin levels were significantly higher in diabetic subjects compared with nondiabetic subjects (11.4+/-5.9 vs 9.8+/-4.3 ng/mL, P=.008). However, this association was lost when adjusted for body mass index (odds ratio [OR], 1.048; 95% confidence interval [CI], 0.997-1.101; P=.067) or waist circumference (OR, 1.050; 95% CI, 0.999-1.104; P=.057). Serum visfatin showed a significant association with obesity even after adjusting for age, sex, and type 2 diabetes mellitus (OR, 1.060; 95% CI, 1.005-1.119; P=.033). Visceral fat, but not subcutaneous fat, was significantly associated with serum visfatin levels even after adjusting for age, sex, type 2 diabetes mellitus, and body mass index (P=.002). In Asian Indians, serum visfatin levels are associated with obesity and visceral fat but not with subcutaneous fat. Although visfatin levels are increased in type 2 diabetes mellitus, the association seems to be primarily through obesity.     

Anti-inflammatory action of exendin-4 in human islets is enhanced by phosphodiesterase inhibitors: potential therapeutic benefits in diabetic patients

Aims/hypothesis  

Exendin-4, a glucagon-like peptide-1 (GLP-1) analogue, is reported to have modest anti-inflammatory effects in addition to that of improving beta cell survival. We therefore sought to determine whether exendin-4 decreases expression of the gene encoding chemokine (C-X-C motif) ligand (CXCL)10, which plays a role in initiating insulitis in type 1 diabetes.