L-glutamic acid-g-poly hydroxyethyl methacrylate nanoparticles: acute and sub-acute toxicity and biodistribution potential in mice

The aim of this safety study in mice was to determine in vivo toxicity and biodistribution potential of a single and multiple doses of L-glutamic acid-g-p(HEMA) polymeric nanoparticles as a drug delivery system. The single dose did not cause any lethal effect, and its acute oral LD₅₀ was >2.000 mg/kg body weight (bw). Multiple doses (25, 50, or 100 mg/kg bw) given over 28 days resulted in no significant differences in body and relative organ weights compared to control. These results are supported by biochemical and histological findings. Moreover, nanoparticle exposure did not result in statistically significant differences in micronucleus counts in bone marrow cells compared to control. Nanoparticle distribution was time-dependent, and they reached the organs and even bone marrow by hour 6, as established by ex vivo imaging with the IVIS^® spectrum imaging system. In conclusion, L-glutamic acid-g-p(HEMA) polymeric nanoparticles appear biocompatible and have a potential use as a drug delivery system.KEY WORDS: biocompatibility, blood biochemistry, genotoxicity, histology, in vivo toxicity, micronucleus test, polymers     

Calcifications of the pulp chamber: prevalence and implicated factors

The objectives of this study were to describe the prevalence of pulp chamber calcifications in a sample of Turkish dental patients and to report associations between presence of pulp chamber calcifications and dental status, gender, age, and cardiovascular diseases (CVDs). Data were collected through radiographic examination of periapical and bitewing radiographs of 15,326 teeth from 536 dental patients, comprising 270 male and 266 female patients aged between 13 and 65 years. Definite radiopaque focuses inside the radiolucent pulp chamber were defined as pulp chamber calcifications. When the pulp chamber was completely radiolucent, that tooth was scored as tooth without pulp chamber calcification. The dental status was scored as intact, carious, restored, or restored + carious. Pulp chamber calcifications were identified in 204 (38%) patients examined. Of the 15,326 teeth, 747 (4.8%) had pulp chamber calcifications. Gender and dental status were found to be correlated with the presence of pulp chamber calcifications. The high prevalence of pulp chamber calcifications in carious, restored, and restored + carious teeth support the view that the occurrence of pulp chamber calcifications can be a response to long-standing irritants. However, to report any associations between occurrence of pulp chamber calcifications and different dental or clinical status, further studies are still needed.     

The effects of amalgam restorations on plasma mercury levels and total antioxidant activity

Objective

This study evaluated the effects of amalgam restorations on plasma mercury levels and total antioxidant activities (TAA).

Design

The study was comprised of 48 subjects ranging in age from 20 to 32 years. Of these, 33 had dental amalgam restorations and 15 had no dental amalgam restorations. In those patients with amalgams, the total number of amalgam restorations and surfaces were counted, and the total and occlusal areas (mm²) of restorations were measured using a Counting Measurement Machine. Blood samples were collected from all participants. Plasma mercury levels were measured using an Atomic Absorption Spectrometer and Hydride System, and plasma TAA levels were measured using an Antioxidant Assay Kit. Statistical analysis was performed using the SPSS 10.01 software program. Data was evaluated by t test and correlation analysis.

Results

Plasma mercury (P-Hg) levels were found to be significantly higher in subjects with amalgam restorations when compared to subjects without amalgams (p < 0.01); the differences in P-TAA levels between subjects with and without amalgams were not found to be statistically significant (p > 0.05). No significant correlations were found between P-Hg concentrations and P-TAA levels (p > 0.05). Significant positive correlations were found between P-Hg concentrations and the number of amalgam restorations (p < 0.01), number of amalgam surfaces (p < 0.05), total amalgam surface area (p < 0.05) and amalgam occlusal surface area (p < 0.01). However, no significant correlations were found between these parameters and P-TAA (p > 0.05).

Conclusions

The results of our study showed that dental amalgams are a major source of plasma mercury; however, amalgam restorations were not found to have a significant effect on plasma-total antioxidant activities.     

Correlation of different MRI characteristics of anterior disc displacement with reduction and without reduction

The aim of this study was to evaluate the correlations between magnetic resonance imaging (MRI) findings in anterior displacement with reduction (ADDR) and anterior displacement without reduction (ADDWR). Two hundred patients with temporomandibular disorder (TMD) symptoms were examined clinically by a clinician experienced with this disorder. There were 130 joints with ADDR and 45 joints with ADDWR; 88 patients were identified according to the clinical and MRI diagnoses of both observers. The MRI characteristics such as position, signal intensity, morphology of disc, degenerative changes, effusion, scar tissue, avascular necrosis, and condylar hypermobility were evaluated in the individual with ADDR and ADDWR. The Chi-square test was used to determine the correlation between MRI characteristics in the ADDR and the ADDWR. There were significant relationships between degenerative changes and increased signal intensity, degenerative changes and side-way displacement, effusion and the deformation of the disc, effusion and subluxation, increased signal intensity and subluxation, elongation deformation and increased signal intensity, and elongation deformation and side-way displacement in ADDR. There were significant relationships between degenerative changes and effusion, degenerative changes and decreased signal intensity, scar tissue and avascular necrosis, deformation of disc and increased signal intensity, as well as deformation of disc and decreased signal intensity in ADDWR. These MRI findings also correlated with the clinical findings, however, this correlation appears to be a synergistic pattern rather than a set of clear-cut relationships. The correlations between these MRIs and different clinical findings such as pain and dysfunction also must be evaluated. Existing correlations must be considered in the diagnosis and treatment planning of TMD, and signs and symptoms of TMD should be monitored after treatment.     

Effect of different surfaces and surface applications on bonding strength of porcelain repair material

This study was done to analyze the effect of different surfaces and different surface applications on the bonding strength of porcelain repair material and to compare these factors with one another. Three different substructures of 10 mm diameter and 4 mm thickness were used for the repair surface: metal, metal on porcelain and porcelain. The surfaces of half of the samples were roughened with an air abrasion tool; the surfaces of the other half were treated with a diamond bur. The specimens were ultrasonically cleaned in distilled water. A silane coupling agent and a bonding agent were applied to the surfaces of all the samples. Resin composite was applied to each specimen. All specimens were stored in distilled water for 24 hours before being thermocycled. After thermocycling, specimens were stored in distilled water for an additional seven days before being subjected to a shear load. The highest bonding strength was observed in the samples with a metal substructure, the surfaces of which were prepared with an air abrasion tool; the lowest bonding strength was observed in the samples with a metal substructure, the surfaces of which were prepared with a diamond bur. When different substructures were examined in terms of bonding strength, the highest bonding strength was statistically observed in metal-on-porcelain substructures, and the lowest bonding strength was observed in the porcelain substructure. When they were examined in terms of surface processes, the highest bonding strength was statistically observed in the samples whose surfaces were prepared with an air abrasion tool, and the lowest bonding strength was observed in the samples whose surfaces were prepared with a diamond bur.     

Associations between the articular eminence inclination and condylar bone changes, condylar movements, and condyle and fossa shapes

Objectives

The purpose of the present study was to determine the inclination and height of the articular eminence with respect to the condylar bone changes, condyle shape, fossa shape and condylar movements in patients with and without temporomandibular joint (TMJ) dysfunction using cone-beam computed tomography (CBCT).

Methods

The associations between the eminence inclination and the condylar bone changes, condylar movements, condylar shape and fossa shape were evaluated in patients with TMJ disorders and control patients without TMJ disorders. The measurements of the articular eminence inclination were established on central sagittal slices of the TMJ. The central coronal slices were used to determine the condyle and fossa shapes. The types of movements of the condyles were determined on open-mouth images, and mandibular hypermobility or hypomobility was noted for each joint.

Results

There were no significant differences in the eminence inclination and height with respect to the condylar bone changes and condylar movements in the TMJ disorder group. However, there was a significant association between the eminence inclination and the fossa shape in the TMJ disorder group and significant associations between the eminence inclination and both the condyle and fossa shapes in the control group. The articular eminence inclination was steeper in the control group than in the TMJ disorder group.

Conclusions

The eminence inclination was steeper in the control patients than in the patients with TMJ disorders, and was not correlated with the condylar bone changes or condylar movements.     

The first histopathological evidence of trimetazidine for the prevention of contrast-induced nephropathy

Aim: We aimed to investigate the prophylactic effects of trimetazidine (TMZ) against contrast-induced nephropathy (CIN) in rat kidneys. Methods and results: 28 Wistar rats were divided into 4 groups of 7 rats each (control (C), contrast media (CM) TMZ, trimetazidin?+?contrast media groups (TMZ?+?CM). The administration of TMZ solution was done on d2, d3 and d4. Fifth day, contrast media was administered at a single dose. On d6 scarification was performed. The oxidant/antioxidant parameters were measured and histopathological scores were performed in kidney tissues. Most of the histopathological scores were significantly higher in the CM group as compared to other groups. Moreover, the scores of the TMZ?+?CM and C groups were not statistically different. CM group, had significantly higher levels of MDA compared to the C and CM?+?TMZ groups (562.82?±?38.15 vs. 419.15?±?49.01 and 507.34?±?14.16 01?nmol/mg protein respectively) (p?0.001). CM group had significantly lower levels of SOD as compared to C, CM?+?TMZ and TMZ groups (p?0.05). Conclusion: To the best of our knowledge, this study for the first time, histopathologically demonstrated the effectiveness of TMZ for the prevention of CIN.     

Transverse testicular ectopia

Described herein are six cases of transverse testicular ectopia. All patients who underwent orchidopexy at the one pediatric surgical unit between October 2001 and January 2008 were evaluated. The medical records of all patients diagnosed with transverse testicular ectopia were evaluated retrospectively. Five patients (84%) were admitted with a symptomatic right inguinal hernia and empty scrotum on the left side. Only one child (16%) had left‐sided hernia and right non‐palpable testis (age ranged from 1 month to 3 years). Four patients (66%) were diagnosed in the operating theatre and the last two (33%) on inguinal ultrasound preoperatively. Magnetic resonance imaging was also performed in the last patient. Herniorrhaphy with fixation of the ectopic gonad to the opposite hemiscrotum through a transseptal incision was performed in all patients. Postoperative complications were not observed.