İlkan Tatar

Hippocampus, glucocorticoids and neurocognitive functions in patients with first-episode major depressive disorders

The aim of this study was to determine whether there was any relationship between hippocampal volume, and glucocorticoid regulation, and cognitive dysfunctions in drug-naïve major depressive disorder (MDD) patients during their first episode. Twenty drug-free female MDD patients in their first episode and 15 healthy females as control subjects were included in the study. All subjects underwent 3.0 Tesla (T) magnetic resonance imaging (MRI), comprehensive neuropsychological testing and dexamethasone suppression tests (DST). The volumes of the right and left hippocampus of the patients were found to be significantly smaller than those of the controls. Patients were found to have significantly lower scores on measures of attention, working memory, psychomotor speed, executive functions, and visual and verbal memory fields. The performance of the patients only in the recollection memory and memory of reward-associated rules were positively correlated with hippocampal volumes. The volumes of the left and right hippocampus did not correlate with basal or post-dexamethasone cortisol levels. Our findings indicate that depressed patients have smaller hippocampi even in the earlier phase of their illness. Further research efforts are needed to explain the mechanisms that are responsible for the small hippocampus in depressed patients.

Association of Adenoid Surface Biofilm Formation and Chronic Otitis Media With Effusion

OBJECTIVES To investigate bacterial biofilm formation on the adenoid surface of pediatric patients undergoing adenoidectomy and to reveal whether this formation is associated with chronic otitis media with effusion (COME). DESIGN Prospective, single-blinded study with scanning electron microscopy. SETTING Dişkapi Yildirim Beyazit Research and Educational Hospital, Ankara, Turkey. PATIENTS Thirty-four children between 4 and 15 years of age (mean age, 7.76 years) who had undergone adenoidectomy from June 1 through December 31, 2007, were divided into 2 groups. The first group (17 children) had undergone adenoidectomy alone, whereas the second group (17 children) had undergone adenoidectomy combined with ventilation tube insertion for COME. MAIN OUTCOME MEASURES Scanning electron microscopy was performed to observe biofilm formation on the surface of adenoid tissues. The biofilm formation was graded according to extension. The roles of adenoid size, age, sex, and duration of COME symptoms were evaluated. RESULTS Biofilm formation was detected on all samples. Adenoids removed from patients with COME had higher-grade biofilm formation than the other group (P = .001). No correlation was found between adenoid size and biofilm formation. CONCLUSION In pediatric patients, adenoid surface biofilm formation may be associated with COME etiopathogenesis.

Occlusal Caries Depth Measurements Obtained by Five Different Imaging Modalities

The study aimed to assess the accuracy and reproducibility of occlusal caries depth measurements obtained from different imaging modalities. The study comprised 21 human mandibular molar teeth with occlusal caries. Teeth were imaged using film, CCD, two different cone-beam computerized tomography (CBCT) units and a microcomputer tomography (micro-CT). Thereafter, each tooth was serially sectioned, and the section with the deepest carious lesion was scanned using a high-resolution scanner. Each image set was separately viewed by three oral radiologists. Images were viewed randomly, and each set was viewed twice. Lesion depth was measured on film images using a digital caliper, on CCD and CBCT images using built-in measurement tools, on micro-CT images using the Mimics software program, and on histological images using AxioVision Rel. 4.7. Intra- and inter-rater reliabilities were assessed according to the Bland/Altman method by calculating Intraclass Correlation Coefficients (ICCs). Mean/median values obtained with intraoral systems were lower than those obtained with 3-D and histological images for all observers and both readings. Intra-observer ICC values for all observers were highest for histology and micro-CT. In addition, intra-observer ICC values were higher for histology and CBCT than for histology and intra-oral methods. Inter-observer ICC values for first and second readings were high for all observers. No differences in repeatability were found between Accuitomo and Iluma CBCT images or between intra-oral film and CCD images. Micro-CT was found to be the best imaging method for the ex vivo measurement of occlusal caries depth. In addition, both CBCT units performed similarly and better than intra-oral modalities.

Prevalence of Biofilms and Their Response to Medical Treatment in Chronic Rhinosinusitis without Polyps

Objective. The aim of this study was to investigate the prevalence of biofilms and the effects of medical treatment modalities in chronic rhinosinusitis (CRS) patients without nasal polyps. Study Design. Randomized controlled trial. Settings. Tertiary referral hospital. Subjects and Methods. The authors randomly divided 32 adult patients with CRS without nasal polyps into 2 groups. In the first group (n = 16), oral clarithromycin was administered 500 mg/bid for 2 weeks and then 250 mg/d for the following 6 weeks. In the second group (n = 16), an 8-week course of 200-mcg/d topical mometasone furoate was added to the clarithromycin regimen, identical to the first group. The pre- and posttreatment nasal tissue samples were evaluated by scanning electron microscopy for biofilm prevalence and graded from 0 to 3 according to density and extension. Results. Biofilms were detected in 24 of 32 patients (75%) before the treatment (grades 1-3). Biofilms were detected in 14 of 32 patients (43.8%) after the treatment (grades 1-2). When each group was evaluated independently, there was a significant improvement after the treatment in both groups I and II. When the biofilm grades of group I were compared to those of group II, there was no significant difference both in the pre- and posttreatment evaluation. Conclusion. The prevalence of biofilms in CRS without polyps was 75% in our study. Regression of biofilms to 43% was observed under medical treatment. Adding nasal steroids to macrolides gave no further benefit.

Ultrastructural and Electrophysiologic Changes of Rat Cochlea after Irradiation

Objective/Hypothesis: To determine the acute and subacute cochlear effects of sublethal total body irradiation.

Comparative micro‐computed tomography evaluation of apical root canal transportation with the use of ProTaper, RaCe and Safesider systems in human teeth

The aim of this study was to compare apical centring ability of nickel titanium (NiTi) ProTaper, RaCe and mainly stainless steel Safesider systems using micro-computed tomography. Thirty freshly extracted mandibular molars with two separate mesial canals and separate foramina were used for the study. Mesial roots were embedded in acrylic resin and instrumented with the ProTaper, RaCe or Safesider systems. Root canal transportation and centring ability of the instruments were evaluated using superimposed micro-computed tomography images of the apical 4 mm of the roots taken at 1 mm intervals. One-way analysis of variance and post hoc Tukeys tests were performed to compare apical transportations. Significant differences were observed between groups at the apical 1, 2 and 3 mm levels (P < 0.05). The reciprocating Safesider system transported root canals significantly more than the other two NiTi systems in the apical 1 mm level (P = 0.001) and more than RaCe system in the apical 2 mm level (P = 0.003). The ProTaper instruments caused more apical root canal transportation than did RaCe instruments at apical 3 mm (P = 0.045). NiTi instrumentation systems showed better centring ability than the mainly stainless steel Safesider system because of the flexible structure of the NiTi alloy.

Association of amoxicillin use and molar incisor hypomineralization in piglets: Visual and mineral density evaluation

AIM The aim of the present study was to determine the prevalence of MIH both visually and quantitatively, and describes the range of mineral densities of enamel specimens from three groups of piglets where two groups were given different doses of amoxicillin in infancy. METHODS In this blind randomized clinical study, 20 piglets were randomly divided into three groups. Group A received a standard dose (50mg/kg/day) and Group B received a high dose (90mg/kg/day) of amoxicillin in selected days of the month (20 working days) they were born. Group K did not receive any medication and served as control. Thirteen right mandibular permanent first molars (PFMs) were randomly collected from 3 groups of piglets at age 10 months for evaluation under X-ray micro-tomography. Tomographic data were obtained using a Skyscan 1174 compact micro-CT in the Department of Anatomy. RESULTS Prevalence of MIH was 0% in all groups. MD values were quantified after enamel grey level (0-255) measurements on horizontal cross-sectional slices. After MD measurements, the effects of amoxicillin use on MIH are presented. CONCLUSIONS While MIH is a multifactorial disturbance, the present study attempted to highlight the clinical findings of a possible relationship between amoxicillin use and MIH with the aid of X-ray micro-tomography.

Effect of Porous Titanium Granules on Bone Regeneration and Primary Stability in Maxillary Sinus: A Human Clinical, Histomorphometric, and Microcomputed Tomography Analyses.

AbstractThe aim of this randomized controlled study was to comparatively analyze the new bone (NB), residual bone, and graft-bone association in bone biopsies retrieved from augmented maxillary sinus sites by histomorphometry and microcomputed tomography (MicroCT) in a split-mouth model to test the efficacy of porous titanium granules (PTG) in maxillary sinus augmentation. Fifteen patients were included in the study and each patient was treated with bilateral sinus augmentation procedure using xenograft (equine origine, granule size 1000–2000 &mgr;m) and xenograft (1 g) + PTG (granule size 700–1000 &mgr;m, pore size >50 &mgr;m) (1 g), respectively. After a mean of 8.4 months, 30 bone biopsies were retrieved from the implant sites for three-dimensional MicroCT and two-dimensional histomorphometric analyses. Bone volume and vital NB percentages were calculated. Immediate after core biopsy, implants having standard dimensions were placed and implant stability quotient values were recorded at baseline and 3 months follow-up. There were no significant differences between groups according to residual bone height, residual bone width, implant dimensions, and implant stability quotient values (baseline and 3 months). According to MicroCT and two-dimensional histomorphometric analyses, the volume of newly formed bone was 57.05% and 52.67%, and 56.5% and 55.08% for xenograft + PTG and xenograft groups, respectively. No statistically significant differences found between groups according to NB percentages and higher Hounsfield unit values were found for xenograft + PTG group. The findings of the current study supports that PTG, which is a porous, permanent nonresorbable bone substitute, may have a beneficial osteoconductive effect on mechanical strength of NB in augmented maxillary sinus.

Validation of micro-computed tomography for occlusal caries detection: an in vitro study

Conventional methods of caries detection, including the gold standard of histological examination, have certain disadvantages that must be addressed prior to validating any other diagnostic technique-current or new. Here we evaluated the validity of micro-computed tomography (micro-CT) as an alternative gold-standard technique for caries detection. Sixty teeth with suspected occlusal caries were chosen from a pool of teeth extracted for orthodontic, periodontal, or surgical reasons. Identical reference points were marked on photographs taken for teeth and were used to evaluate each method. Dimensions of caries were assessed by two calibrated examiners using the ICDAS-II visual examination system, bitewing radiographs, and micro-CT. The teeth included in the study were selected randomly from solution before all measurements. For micro-CT, the device was set to 50 kV, 800 µA, pixel size 15 µm (at 1024 × 1024 resolution), and 1° rotation step. NRecon software (SkyScan) was used to obtain reconstructed images. For each diagnostic method, results were compared with histology results using the McNemar test. Receiver operator characteristic (ROC) analysis was also performed for each method (Z-test; p < 0.05). Besides showing a high correlation with histology results, micro-CT yielded the greatest values at the D3 threshold; moreover, accuracy and area under the ROC curve (AUC) values were greatest at the D1threshold. Our results indicate that micro-CT performs as well as or better than histological examination for the purpose of comparing methods for caries detection.

Impact of cadaveric surgical anatomy training on urology residents knowledge: a preliminary study.

OBJECTIVE Cadaveric dissection is used as a major tool for anatomy education at the medical school. In this study we aimed to determine how a uro-anatomy cadaveric dissection course would impact urology residents knowledge. MATERIALS AND METHODS A three days course was given to 50 urology residents by experienced trainers in 1-3 June 2012 at Ege University Medical Schools Anatomy Department, İzmir, Turkey. Efficacy of the course was assessed using a multiple choice questionnaire of 20 questions given before and after the course. RESULTS Completed questionnaires before and after the course were available for 25 residents (50%) that were included. Residents answered correctly to 11.7 out of 20 questions (59%) before the course and 13.0 out of 20 (65%) after (p<0.05). In individuals analysis, 16 residents (64%) increased their scores, 4 (16%) had similar scores and 5 (20%) had lower scores. The number of correct answers for 6 out of the 20 questions was lower following the course. CONCLUSION This cadaveric surgical anatomy course was effective in improving surgical anatomy knowledge for most urology residents but not all and helped to identify ways to improve the course in the future.