Valproate Effects on Chemophysical Properties of Human Serum Albumin

Albumin has a fundamental role in human body. Its main tasks in blood are to regulate osmotic blood pressure, maintaining the pH, and transporting metabolites and drugs throughout the vascular system.  Pharmacological studies of the interaction of drugs on HSA are important due to structural and functional changes of this vital protein; thus, here in this research the effect of valproate as a common drug for epilepsy disorders is evaluated in the presence of hexadecyl pyridinium bromide (HPB) as a positive surfactant in normal and fever condition. Electrochemical method was used to investigate the binding number of HPB molecules to HSA in the absence and presence of valproate by evaluating the concentration of free HPB in 37oC and 42oC temperatures. HSA affinity for valproate binding studied via ligand binding process for normal and fever temperatures. The findings indicate that, there is a significant difference in valproate binding to albumin at physiological and pathological temperatures. The consequences are the same in the presence of HPB; in other words, HSA binding tendency to HPB in the presence of valproate was totally altered because of HSA major conformational changes in fever condition. In conclusion, corrected dosage of valproate is needed for fever condition relative to normal temperature and the patients under prescription of different medications in fever condition should have different orders due to the interferences of drugs.

Scanning Electron Microscopic Evaluation of Residual Smear Layer Following Preparation of Curved Root Canals Using Hand Instrumentation or Two Engine-Driven Systems

Introduction: In this experimental study, the amount of smear layer (SL) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated. Methods and Materials: Forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to Schneider’s method) were divided into three groups (n=16) which were prepared by either the ProTaper Universal file series, Reciproc single file system or hand instrumentation. The canals were intermittently irrigated with 5.25% NaOCl and 17% (ethylenediaminetetraacetic acid) EDTA, followed by distilled water as the final rinse. The roots were split longitudinally and the apical third of the specimens were evaluated under 2500× magnification with a scanning electron microscope (SEM). The mean scores of the SL were calculated and analyzed using the non-parametric Kruskal-Wallis and Mann-Whitney U tests. Results: The mean scores of the SL were 2.00±0.73, 1.94±0.68 and 1.44±0.63 µm for the ProTaper Universal, Reciproc and hand instrumentation, respectively. Mean score of SL was significantly less in the hand instrumentation group than the ProTaper (P=0.027) and Reciproc (P=0.035) groups. The difference between the two engine-driven systems, however, was not significant (P=0.803). Conclusion: The amount of smear layer in the apical third of curved root canals prepared with both engine-driven systems was similar and greater than the hand instrumentation technique. Complete cleanliness was not attained.Keywords: Canal Preparation; Endodontics; Irrigants; Scanning Electron Microscopy; Smear layer

Evaluation of the Ki-67 and MCM3 Expression in Cytologic Smear of Oral Squamous Cell Carcinoma

Statement of the Problem: Squamous cell carcinoma (SCC) is the most frequent oral cancer whose 5-year survival rate is 80% for early-detected lesions and nearly 30-50% for advanced lesions. Early detection of oral cancers and precancerous lesions can improve the patient’s survival and decrease the morbidity. Purpose: This study aimed to evaluate and compare the Ki-67 and MCM3 expression in cytologic smear of oral SCC (OSCC). Materials and Method: We examined 48 oral brush biopsies including 28 OSCC and 20 healthy non-smoking samples. Immunocytochemistry staining was performed for Ki-67 and MCM3 by using an EnVision-labeled peroxidase system, and labeling index (LI) was calculated. Results: Out of 28 OSCC cases, 27(96.4%) cases contained MCM3 positive cells and 22(78%) cases contained Ki-67 positive cells. All normal mucosa were Ki-67 and MCM3 negative. MCM3 and Ki-67 LI were significantly higher in OSCC than normal mucosa (p< 0.001). MCM3 LI was significantly higher than Ki-67 LI in OSCC group (p< 0.001). Conclusion: Immunocytologic evaluation of Ki-67 and MCM3 can be used for early detection of OSCC. Furthermore, MCM3 may be a more sensitive cytologic biomarker than Ki-67 in SCC patients