Atif Aydinlioglu

Anatomic variations of the paranasal sinuses: CT examination for endoscopic sinus surgery

Chronic rhinosinusitis endoscopic surgery requires an accurate evaluation of diseases and paranasal sinus anatomic variations. This study aims to show the main anatomical variations in the ostiomeatal complex and paranasal sinuses which are usually depicted by computed tomography (CT). CT scans obtained 2 mm thickness in axial and coronal plane from a series of 200 patients with chronic sinusitis were examined to determine the prevalence of anatomic variants. Anatomical variations determined were supraorbital recess in 6%, concha bullosa in 30%, sphenomaxillary plate in 17%, infra-orbital ethmoid cells (Hallers cells) in 6%, spheno-ethmoid cells (Onodis cells) in 12%, pneumatization of the anterior clinoid process in 6%, carotid artery bulging into the sphenoid sinus in 8%, pneumatization of the uncinate process in 2%, paradoxical curvature of the middle turbinate in 3% and septal deviation in 36%. Level difference between the ethmoid roof and nasal vault was an average of 8 mm in right side and 9.5 mm in left side. Awareness of these different variations will help the rhinologic surgeon in his orientation during endoscopic surgical procedures.

Brief Communication SEX DIFFERENCES AND RIGHT-LEFT ASYMMETRIES IN RAT HIPPOCAMPAL COMPONENTS

Previous reports have indicated morphologic hippocampal asymmetry in thickness in male and female rats. In the present study, the possible sex differences and right-left asymmetries in rat hippocampal components were investigated. Pyramidal cells in four hippocampal sectors on thionin-stained sections were counted and the thickness of the hippo campal components was measured on microslide-projected images. The present study showed significant sexual dimorphism in two hippocampi as well as asymmetry in male. These findings agree with those found in humans.

The effect of mobile phone on the number of Purkinje cells: A stereological study

Purpose: The World Health Organisation proposed an investigation concerning the exposure of animals to radiofrequency fields because of the possible risk factor for health. At power frequencies there is evidence to associate both childhood leukaemia and brain tumours with magnetic field exposures. There is also evidence of the effect of mobile phone exposure on both cognitive functions and the cerebellum. Purkinje cells of the cerebellum are also sensitive to high dose microwave exposure in rats. The present study investigated the effect of exposure to mobile phone on the number of Purkinje and granule neurons in the developing cerebellum. Material and methods: Male and female Swiss albino mice were housed as control and mobile phone-exposed groups. Pregnant animals in the experimental group were exposed to Global System for Mobile Communication (GSM) mobile phone radiation at 890–915 MHz at 0.95 W/Kg specific absorption rate (SAR). The cerebella were processed by frozen microtome. The sections obtained were stained with Haematoxylin-eosin and cresyl violet. For cell counting by the optical fractionator method, a pilot study was firstly performed. Cerebellar areas were analysed by using Axiovision software running on a personal computer. The optical dissectors were systematically spaced at random, and focused to the widest profile of the neuron cell nucleus. Results: A significant decrease in the number of Purkinje cells and a tendency for granule cells to increase in cerebellum was found. Conclusion: Further studies in this area are needed due to the popular use of mobile telephones and relatively high exposure on developing brain.

THE RELATIONSHIP OF CALLOSAL ANATOMY TO PAW PREFERENCE IN DOGS

Previous studies have described the paw preference and asymmetry in dog brains, based on experimental studies. The purpose of the present study is to investigate a possible association between callosal anatomy and paw preference in dogs. The midsagittal area of the dog corpus callosum was measured in its entirety and in six subdivisions in a sample of 21 brains obtained from 9 male and 12 female mongrel dogs which had paw preference testing. The present study showed significant paw differences in dog corpus callosum. A posterior segment of the callosum, the isthmus, was significantly larger in the right pawedness than the left.

Effect of Prenatal Exposure to Mobile Phone on Pyramidal Cell Numbers in the Mouse Hippocampus: A Stereological Study

Because of the possible risk factor for the health, World Health Organization (WHO) recommended the study with animals on the developing nervous system concerning the exposure to radiofrequency (RF) field. A few studies related to hippocampal exposure are available, which indicate the impact of RF field in some parameters. The present study investigated the effect of exposure to mobile phone on developing hippocampus. Male and female Swiss albino mice were housed as control and mobile phone exposed groups. The pregnant animals in tested group were exposed to the effects of mobile phone in a room possessing the exposure system. The left hemispheres of the brains were processed by frozen microtome. The sections obtained were stained with Hematoxylin & Eosin. For cell counting by the optical fractionator method, a pilot study was first performed. Hippocampal areas were analyzed using Axiovision software running on a personal computer. The optical dissector, systematically and randomly spaced, was focused to the widest profile of the pyramidal cell nucleus. No significant difference in pyramidal cell number of total Cornu Ammonis (CA) sectors of hippocampus was found between the control and the mobile phone exposed groups (p > .05). It was concluded that further study is needed in this field due to popular use of mobile telephones and relatively high exposure to the developing brain.

Morphologic evaluation of the ulna

Intramedullary ulnar nailing may be technically difficult. We used various methods and measurements to determine the ideal nail entry point and the shape, length, diameter and curvature of the medullary canal in 44 human cadaver ulnas. We found that the ideal nail entry point was, on average, 7 mm proximal and 3 mm lateral to the most prominent area of the olecranon. A nail of 3 mm diameter could easily be inserted through a hole at the proximal-lateral side of the most prominent part of the olecranon, but only 20% of all nails could be easily inserted through a hole in the middle of the olecranon. We found that correct selection of a nail of proper length and diameter, as well as an ideal nail entry point on the olecranon are essential to successful nailing.

Aperture in coronoid-olecranon septum: A radiological evaluation.

Background: The humerus bone with coronoid-olecranon septal aperture have very narrow medullary canal and extreme anterolateral bowing proximally and/or extreme anterolateral compressed surface at distal part. Septal perforation might make nailing through a retrograde technique more difficult or possibly with an increased risk of iatrogenic fracture at the site of insertion. Coronoid-olecranon perforation might be very important in preoperative planning for successful nailing. Since the data available has been obtained from the ancient studies using the skeletal material, the present study is aimed at investigating originally the presence of the coronoid-olecranon septum perforation in the living subjects, using a radiographic method. Materials and Methods: The study was performed on direct radiograms and computed tomography of the elbow obtained from the 709 volunteers (367 males, 342 females). Results: The incidence of the perforation was found to be 8.6 %. Bilateral occurrence was found to be more common significantly. The highest incidence occurred in second decade. Conclusion: The present study suggests female prepronounced and left asymmetry in case of septal perforation. Bilateral occurrence from our study might be peculiar to the clinician.

THE RELATIONSHIPS OF DOG HIPPOCAMPUS TO SEX AND PAW PREFERENCE

Previous studies have described paw preference and asymmetry in dog brains. Electrical activity of the dorsal hippocampus also indicated the existence of hippocampal asymmetry in dogs. In the present study, the possible paw and sex-related asymmetries and right-left differences in dog hippocampus were investigated. The hippocampus was dissected and weighed. Each hippocampus was cut into slices by the slicing apparatus placed horizontally on the tissues. The volumetric measurements were performed using the formula modified from the Cavalieri principle. The present study indicated the significant sex and paw differences and no right-left asymmetry in dog hippocampi. The morphological asymmetries in normal subjects might be related to functional hippocampal asymmetries in memory or in cognitive skills.

A morphometric study on dog cerebellum

Abstract In healthy humans and patient with schizophrenia, studies investigating cerebellar asymmetries have been performed by using magnetic resonance images (MRIs), which have failed to demonstrate the presence of the left-right asymmetry. Due to the paucity of animal studies in this field, the present study was undertaken to investigate whether the dog cerebellum shows any pattern of volumetric asymmetry. A total of 16 adult mongrel dogs, 8 male and 8 female, were assessed with respect to pawedness. After the animals were anesthetized and killed by exsanguinations, the cerebellum was removed and divided into the anterior and the posterior lobes by a dissection passing into the fissure prima. The volumes of the right and left hemispheres were separately calculated by a volumetric device. The present study demonstrated significant volume asymmetries as to right-left, sex and pawedness in dog cerebellum. Morphological asymmetries in dog cerebellum might relate to cerebral specialization of function. Further studies need to be performed to demonstrate the relationship between cerebellar asymmetries and functional lateralization.

Anatomical characteristics of the tibial medullary canal and their implications for intramedullary fixation.

The use of intramedullary fixation methods in the tibia is limited by the anatomical characteristics of this bone. In this study, the shape and degree of axial lateral rotation of the medullary canal were determined in 45 human dry cadaver bones using X-ray and computed tomography examinations and direct measurement of rotation in inserted nails. Forty bones (88.8%) had slight and five bones (11.1%) had excessive anterior bowing along the tibial shaft. Six of the 45 bones (13.3%) had an extremely narrow medullary canal. Axial lateral rotation was demonstrated in the middle third of the medullary canal, being on average (± SD) 32.35 ± 16.25° (range 10-75°). This study revealed that extreme narrowing of the medullary canal, axial lateral rotation of the medullary canal, and extreme anterior bowing of the tibial shaft are the anatomical characteristics most likely to cause difficulties when using intermedullary fixation in the tibia.