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Dive into the research topics where Bunyamin Sahin is active.

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Featured researches published by Bunyamin Sahin.


European Journal of Radiology | 2003

Unbiased estimation of the liver volume by the Cavalieri principle using magnetic resonance images

Bunyamin Sahin; Mehmet Emirzeoglu; Ahmet Uzun; Lutfi Incesu; Yüksel Bek; Sait Bilgic; Süleyman Kaplan

OBJECTIVE It is often useful to know the exact volume of the liver, such as in monitoring the effects of a disease, treatment, dieting regime, training program or surgical application. Some non-invasive methodologies have been previously described which estimate the volume of the liver. However, these preliminary techniques need special software or skilled performers and they are not ideal for daily use in clinical practice. Here, we describe a simple, accurate and practical technique for estimating liver volume without changing the routine magnetic resonance imaging scanning procedure. MATERIALS AND METHODS In this study, five normal livers, obtained from cadavers, were scanned by 0.5 T MR machine, in horizontal and sagittal planes. The consecutive sections, in 10 mm thickness, were used to estimate the whole volume of the liver by means of the Cavalieri principle. The volume estimations were done by three different performers to evaluate the reproducibility. RESULTS There are no statistical differences between the performers and real liver volumes (P > 0.05). There is also high correlation between the estimates of performers and the real liver volume (r = 0.993). CONCLUSION We conclude that the combination of MR imaging with the Cavalieri principle is a non-invasive, direct and unbiased technique that can be safely applied to estimate liver volume with a very moderate workload per individual.


Journal of Microscopy | 2001

A simple technique to measure the movements of the microscope stage along the x and y axes for stereological methods

Süleyman Kaplan; Sinan Canan; H. Aslan; Unal B; Bunyamin Sahin

Measurements of microscope stage movements in the x and y directions are of importance for some stereological methods such as the optical disector and optical fractionator. The length of stage movements can be measured with great precision and accuracy using a suitable motorized stage, which is generally a computer‐assisted instrument. This type of equipment is generally too expensive for and not readily available in many laboratories. This paper describes a simple method to measure the movements of the microscope stage along the x and y directions, which can be used for purposes such as systematic uniform random sampling. It needs a microscope attachment consisting of two dial indicators; one of them is used to measure the amount of stage movement along the x‐axis and the other measures the amount of movement along the y‐axis. Movements of the stage on the micrometre‐scale can be measured easily using this device.


Annals of Plastic Surgery | 2007

Comparison of Three Methods for the Estimation of Total Intracranial Volume Stereologic, Planimetric, and Anthropometric Approaches

Niyazi Acer; Bunyamin Sahin; Orhan Bas; Tolga Ertekin; Mustafa Usanmaz

There is a well-known close relationship between the total intracranial volume (TIV) and the brain size. Several studies in different countries have estimated the cranial capacity, which indirectly reflects the brain volume. However, we have not seen a study evaluating the results of the methodologies for the assessment of TIV. This study was carried out on 30 normal subjects whose ages ranged between 19 and 77 years old (males, 18; females, 12). Three different methods were used to assess the TIV. The mean (±SD) estimated TIV using linear dimensions method in males and females were 1416.8 ± 64 cm3 and 1291.9 ± 152 cm3, respectively. The mean estimated TIV using point counting method in males and females was 1474 ± 93 cm3 and 1252 ± 72 cm3, respectively. By using the planimetric method of the mean and SD of TIV, male and females were 1492.1 ± 74 cm3 and 1319.6 ± 100 cm3, respectively. There were no statistical difference between TIV measurements obtained using the optimized stereologic technique and planimetry (P > 0.05). TIV between males and females was statistically significant (P < 0.001). This study showed that there are minor differences among the given 3 distinct methods. With the disadvantage of requiring more time to apply, the planimetry and point counting methods provide more assumption-free results than the anthropometric approach. However, the anthropometric method can be applied to assess TIV without needing sophisticated tools.


Brain Research | 2006

Neonatal pinealectomy induces purkinje cell loss in the cerebellum of the chick : A stereological study

Ayten Türkkani Tunc; Mehmet Turgut; Hiiseyin Aslan; Bunyamin Sahin; Mine Ertem Yurtseven; Süleyman Kaplan

Melatonin plays an important role in certain physiological functions and morphological features of various structures. In the current study, the effects of pinealectomy on Purkinje cell number and morphological features of developing cerebellum in the chick were investigated using stereological methods. Fifteen Hybro Broiler newly hatched chicks were divided into three groups: a pinealectomized group (n = 5), sham-operated group (n = 5) and a non-pinealectomized control group (n = 5). Surgical pinealectomy was performed in 3-day-old chicks. In the 8th week, all animals were sacrificed for histopathological evaluation and subsequent stereological analysis. Each layer volume of molecular (+Purkinje cell), granular and white matter in the cerebellum was estimated in all animals. It was found that there was no significant difference for the volume of whole cerebellum and also molecular (+Purkinje cell) layer in these groups (P > 0.05). Nevertheless, the values of granular layer and white matter of sham-operated group were significantly different from those of control and pinealectomized animals (P < 0.01). It was also observed that pinealectomy significantly reduces the Purkinje cell number in cerebellar cortex (P < 0.01). The present study is the first stereological study to demonstrate the histomorphological effects of pinealectomy on the cerebellum in the chick. Our results suggest that pineal gland/melatonin might play an important role in morphological features of the developing cerebellum in the chick.


Clinical Neurology and Neurosurgery | 2005

A new approach for the estimation of intervertebral disc volume using the Cavalieri principle and computed tomography images

Sait Bilgic; Bunyamin Sahin; Osman Fikret Sonmez; Ersan Odaci; Serdar Colakoglu; Süleyman Kaplan; Hayati Ergur

This study was carried out to describe a simple, accurate and practical technique for estimating the volume of intervertebral disc (ID) by the combination of the Cavalieri principle and computed tomography (CT) images. Total eight lumbar IDs from two cadavers were CT scanned in axial, sagittal and coronal sections. The consecutive sections with 5 and 3mm thickness were used to estimate the volume of the IDs by the Cavalieri principle. Three investigators estimated the volume of IDs independently to evaluate inter-observer differences. When the results were compared to the real volumes of IDs measured by the fluid displacement technique, there was no significant difference between the real volume measurements and the Cavalieri estimation results of ID volumes (P > 0.05). Moreover, findings of three investigators did not show significant variations (P > 0.05). Our results indicate that the section thickness and the section planes did not affect the accuracy of the disc volume estimation. Thus the combination of CT scanning with the Cavalieri principle may be used as a direct and reliable technique to estimate the volume of IDs with a mean of 4 min workload per ID.


Brain Research | 2007

Effect of prenatal exposure to diclofenac sodium on Purkinje cell numbers in rat cerebellum: a stereological study.

Murat Cetin Ragbetli; Birsen Ozyurt; Hüseyin Aslan; Ersan Odaci; Alpaslan Gökçimen; Bunyamin Sahin; Süleyman Kaplan

Diclofenac sodium (DS) is commonly used as a non-steroidal anti-inflammatory drug. Although several adverse effects are clearly established, it is still unknown whether prenatal exposure to DS has an effect on the development of the cerebellum. In this study, we investigated the total number of Purkinje cells of the cerebellum in a control group and in a DS-treated group of male rats using a stereological method. The DS in a dose of 1 mg/kg daily was intraperitoneally injected to the drug-treated group of pregnant rats beginning from the 5th day after mating for a period of 15 days during pregnancy. Physiological serum at 1 ml dose was intraperitoneally injected to the control group of pregnant rats at the same period. After delivery, male offspring were obtained and each main group was divided into two subgroups that were 4-week-old (4W-old) and 20-week-old (20W-old). Our results showed that the total number of Purkinje cells in offspring of drug-treated rats was significantly lower than in the offspring of control animals. These results suggest that the Purkinje cells of a developing cerebellum may be affected by administration of DS during the prenatal period.


Surgical and Radiologic Anatomy | 1997

Rare arterial variation: a common trunk from the external iliac artery for the obturator, inferior epigastric and profunda femoris arteries

S. Bilgiç; Bunyamin Sahin

In this anomaly, observed in the right pelvic region of a female newborn cadaver among 100 studied (1%), a common arterial trunk arose from the medial side of the external iliac a. 1 cm proximal to the inguinal ligament. The trunk first divided into an ascending branch, which finally divided into the obturator and inferior epigastric arteries, and a descending branch, the profunda femoris a. from which arose the medial circumflex femoral a. The origin of the profunda femoris, obturator and inferior epigastric aa. is explained on the basis of the embryologic development and their course and variations are compared with reports in the literature.


Acta Neurochirurgica | 2002

Therapeutic Effects of Intracarotid Infusion of Spermine/Nitric Oxide Complex on Cerebral Vasospasm

Osman Fikret Sonmez; Bunyami Unal; S. Inalöz; Bunyamin Sahin; Mustafa Yilmaz; A. Aydın; Süleyman Kaplan

Summary. Background: Vasospasm is one of the underlying causes of morbidity and mortality in subarachnoid haemorrhage (SAH). The therapeutic effects of intracarotid infusion of spermine/nitric oxide complex (SPER/NO) on cerebral vasospasm in an experimental model of SAH were investigated. Method: Twenty-four adult male New Zealand white rabbits (2.6–3.4 kg in weight) were randomly divided into four groups (n=6), as follows: (I) control group (without SAH and drug), (II) SAH alone group (with SAH, without drug), (III) SAH placebo group (with SAH and saline), and (IV) SAH-SPER/NO group (with SAH and SPER/NO). The fresh autologous non-heparinized blood was injected into the cisterna magna to induce a SAH, after 24 hour SAH, the substance (saline or SPER/NO) was delivered to animals. All rabbits were scarified at 48-hours of induced SAH. The basilar artery with surrounding tissue was removed from the cranium and processed for paraffin embedding. Histopathological and stereological examinations of the basilar artery were done. Findings: In the SPER/NO treated group of rabbits, the histopathological changes were less severe than in the SAH-alone and SAH-placebo groups. Regarding the intracarotid pressure, there was a statistically significant difference between SAH-alone and SAH-SPER/NO groups and also between SAH-SPER/NO and control groups (p<0.05). The mean cross sectional area of basilar arteries was 0.26 mm2 in the control, whereas in SAH alone, placebo and SAH-SPER/NO groups were 0.13, 0.15 and 0.20 mm2, respectively. Interpretation: It is well known that NO is a critical substance involved in cerebral vascular dynamics. Present results indicate that treatment of vasospasm with SPER/NO in SAH may be promising. However, further studies should be done on this substance to clarify its effect on vasospasm before using the drug in clinical situations.


Developmental Brain Research | 2002

Estimation of numerical density and mean synaptic height in chick hippocampus 24 and 48 hours after passive avoidance training.

Bunyami Unal; P.M. Bradley; Bunyamin Sahin; Sinan Canan; Hüseyin Aslan; Süleyman Kaplan

The effects of passive avoidance learning on synaptic morphology and number in the dorsolateral hippocampus of chick were investigated at 24 and 48 h after training. Chicks of both sexes were used. The numerical density of synapses and mean synaptic height were determined using design-based quantitative electron microscopic techniques. Our results suggest that after training there is a significant increase in synaptic density in the dorsolateral hippocampus of chicks at both 24 and 48 h, and also that the mean synaptic height was significantly different between trained and control groups. The increase in synaptic density was due to shaft (type II) synapses. It is known that during synaptogenesis, shaft synapses are formed first and are then converted to spine synapses. The only hemispheric asymmetry was found in the 24 h water-trained (W-trained) males where the numerical density of spine synapses was significantly higher in the left hippocampus. No significant differences due to gender in either numerical synaptic density or synapse height were observed at either 24 and 48 h. Comparison of the 24 h with 48 h groups showed an increase in shaft synaptic density over time in the W-trained groups, and an increased density of both shaft and spine synapses with time in methylanthranilate-trained (MeA-trained) chicks. These results demonstrate that the dorsolateral hippocampus of the chick shows synaptic changes at both 24 and 48 h after training and implicates this region in the long-term memory process.


Journal of Craniofacial Surgery | 2009

Stereological Estimation of the Orbital Volume: A Criterion Standard Study

Niyazi Acer; Bunyamin Sahin; Hayati Ergur; Hulki Basaloglu; Nazl Gülriz Ceri

Several methodologies have been proposed to assess the orbital volume (OV). However, we have not seen a criterion standard study evaluating the results of the methodologies for the assessment of OV. In the current study, the actual OV of 9 dry skulls was measured using the water filling method as the criterion standard. Consecutive computed tomographic sections at a thickness of 1.5 mm were used to estimate the OV by means of the point counting method. The mean (SD) of the OV measured by the water filling method was 17.84 (1.56) cm3. By using the point counting method, it was 17.05 (1.69) cm3. There was no statistically significant difference between sides (P > 0.001). The results of the OV values obtained by the two methods were compared statistically. The agreements between the two methods were also evaluated using the Bland-Altman plots. There was no statistically significant difference between the OV measurements obtained by the stereological technique and water filling method. The described method could be used for the assessment of OV in vivo.

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Amani Elfaki

Ondokuz Mayıs University

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Ersan Odaci

Karadeniz Technical University

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Sait Bilgic

Ondokuz Mayıs University

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Orhan Bas

Afyon Kocatepe University

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