The effect of nitrazepam on depression and curiosity in behavioral tests in mice: The role of potassium channels.

Evidence show that gamma-aminobutyric acid (GABA) receptors are involved in depression, so the aim of this study was to investigate the effect of nitrazepam as agonist of GABAA receptors on depression and curiosity in male mice and the role of potassium channel in antidepressant-like response. For this purpose, we studied the antidepressant-like properties of fluoxetine, nitrazepam, glibenclamide, and cromakalim by both forced swimming test (FST) and tail suspension test (TST). Animals were injected by various doses of nitrazepam (0.05, 0.1, and 0.5mg/kg). Nitrazepam at dose of 0.5mg/kg significantly decreased the immobility time compared to control group in both FST and TST. Fluoxetine also showed such a response. Co-administration of nitrazepam (0.05mg/kg) with glibenclamide in TST (1mg/kg) and in FST (0.3, 1mg/kg) also showed antidepressant-like response. Beside, cromakalim (0.1mg/kg) could reverse the antidepressant-like effect of nitrazepam (0.5mg/kg) in both FST and TST, while cromakalim and glibenclamide alone could not change the immobility time compared to control group (P>0.05). The hole-board test revealed that nitrazepam at doses of 0.5 and 0.1mg/kg could increase the activity of the animal's head-dipping and boost the curiosity and exploration behavior of mice. The results of this study revealed that nitrazepam may possess antidepressant-like properties and this effect is dependent to potassium channels in both FST and TST.

Dentists' knowledge, attitude, and practice regarding oral cancer in Iran.

Dentists are usually the first group who can examine patients for oral cancer and the early diagnosis highly depends on their knowledge. In this study, we aim to survey the Iranian dentists' knowledge, attitude, and behaviors regarding oral cancer. A valid and reliable self-administered questionnaire was designed and sent to 150 dentists. Responses to the questionnaires were analyzed using descriptive and analytical statistics. Just one fifth of the dentists reported to perform oral cancer examination for all of their patients in age of 40 and above and about 34 % of them were knowledgeable. They mostly claimed that the lack of knowledge is the main barriers to the provision of routine oral cancer examinations. The opinion of dentists about the effectiveness of continuing education courses supports the development of these courses on oral cancer. Besides, more emphasis should be placed on oral cancer prevention in dental schools.

Circular symmetric laplacian mixture model in wavelet diffusion for dental image denoising.

In this paper, we try to find a particular combination of wavelet shrinkage and nonlinear diffusion for noise removal in dental images. We selected the wavelet diffusion and modified its automatic threshold selection by proposing new models for speckle-related modulus. The Laplacian mixture model, Rayleigh mixture model, and circular symmetric Laplacian mixture models were evaluated and, as it could be expected, the latter provided a better model because of its compatibility with heavy tailed structure of the wavelet coefficients besides their interscale dependence. The numerical evaluation of contrast-to-noise ratio (CNR) along with simple observation of the results showed reasonably acceptable improvement of CNR from 2.9149 to 38.8813 in anterior--posterior images, from 41.6131 to 86.3141 in cephal-lateral images, from 13.6414 to 43.4711 in intraoral pictures, and from 6.0102 to 31.8771 in panoramic datasets. Furthermore, technical ability of the proposed filtering method in retaining the possible cavities on dental images was evaluated in two datasets with natural and artificially applied cavities.

Removing Distortion of Periapical Radiographs in Dental Digital Radiography Using Embedded Markers in an External frame.

To carry out in vivo and in vitro comparative pilot study to evaluate the preciseness of a newly proposed digital dental radiography setup. This setup was based on markers placed on an external frame to eliminate the measurement errors due to incorrect geometry in relative positioning of cone, teeth and the sensor. Five patients with previous panoramic images were selected to undergo the proposed periapical digital imaging for in vivo phase. For in vitro phase, 40 extracted teeth were replanted in dry mandibular sockets and periapical digital images were prepared. The standard reference for real scales of the teeth were obtained through extracted teeth measurements for in vitro application and were calculated through panoramic imaging for in vivo phases. The proposed image processing thechnique was applied on periapical digital images to distinguish the incorrect geometry. The recognized error was inversely applied on the image and the modified images were compared to the correct values. The measurement findings after the distortion removal were compared to our gold standards (results of panoramic imaging or measurements from extracted teeth) and showed the accuracy of 96.45% through in vivo examinations and 96.0% through in vitro tests. The proposed distortion removal method is perfectly able to identify the possible inaccurate geometry during image acquisition and is capable of applying the inverse transform to the distorted radiograph to obtain the correctly modified image. This can be really helpful in applications like root canal therapy, implant surgical procedures and digital subtraction radiography, which are essentially dependent on precise measurements.