Biomedical subjects

Bünyami Unal

Publications and source records attributed to Bünyami Unal.

5 recordsLinked to original sources

PubMed2006

Stereological evaluation of treatment response in patients with non-resectable hepatic alveolar echinococcosis using computed tomography via the Cavalieri method.

INTRODUCTION: The purposes of this study were to describe and adapt the relevant methods of computed tomography (CT) and stereology to estimate parasitic volume in the liver, to compare the efficiency of benzimidazole treatment in hepatic alveolar echinococcosis (AE), and to determine whether the response rates measured by the stereological method are correlated with those measured by simple volumetric measurements (SVM). METHODS: Nine eligible patients with non-resectable AE were included in the study. By using their abdominal CT at the baseline and after a year of treatment, treatment responses of the cases were evaluated both by the stereological method via a software and by SVM, retrospectively. The volume estimation was performed in our study using a different approach that consisted of three separate stages combined with the Cavalieri method of modern design stereology. RESULTS: The response rates were -17 +/- 55% and -12 +/- 37% by the Cavalieri method and SVM, respectively; however, they were not statistically significant (P = 0.59 and 0.21 for the Cavalieri method and SVM, respectively). Although some cases had comparable results, others had different response rates, and the two methods showed no significant correlation (r = -0.31, P = 0.41). CONCLUSIONS: Because this modified method provides accurate results by reducing margin of errors, even in case of bizarre shape of AE, a correct, unbiased, and reliable management of the cases with AE via this method may be possible. Owing to lack of a correlation with SVM, it is suggested that a measurement via SVM may be wrong and its use in the evaluation of the treatment response in such cases will not be sufficient and completely true.

Adult↗

PubMed2006

Effect of a high fat diet on quantitative features of adipocytes in the omentum: an experimental, stereological and ultrastructural study.

BACKGROUND: Omental adipose tissue specimens of female rats that were fed a high fat (HF) diet were evaluated stereologically and histopathologically. To our knowledge, there is no stereological study on numerical density, nuclear height and volume of adipocytes in omental adipose tissue in the female rat fed a HF diet in the literature. METHOD: 20 female Spraque Dawley rats were used in the study. 10 of the animals were fed HF diet consisting of 30% of calories from fat for 3 months. The remaining 10 rats, the control group, were fed a normal diet. After the experimental procedure, all animals were anesthetized and omental adipose tissues in the same area were dissected and fixed for the histochemical process using a mixture of 3% glutaraldehyde and 1% osmium tetraoxide in 0.1 M phosphate buffer. After embedding of tissues in araldite CY 212, semi-thin and thin sections were cut. The semi-thin sections were stained with toluidine blue. The physical dissector counting method was used for estimation of numerical density and nuclear height of adipocytes. Cavalieri principle was used for the estimation of adipocyte volume; volume fraction approach was applied to find the volume fraction of adipose tissue components. RESULTS: The mean numerical density of adipocytes in the HF diet group was significantly higher than the control. The mean nuclear height of adipocytes was also very high in the HF diet group. The volume fraction of adipose mass was increased whereas the extracellular matrix volume fraction was reduced in the HF diet group compared to the controls. The mean volume of adipocytes in the HF diet group was also significantly higher than in the control group. At the light microscopy level, it was found that adipocytes were enlarged and gaining irregular shape in the HF diet group. Thicker basal lamina and electron dense lipid content were also found in this group at the electron microscopy level. CONCLUSION: Lipid content and number of adipocytes in the adipose tissue of HF diet rats were higher than in the controls. Thus, HF diet induces increase in body weight via both hypertrophy and hyperplasia of adipocytes.

Adipocytes↗

PubMed2005

Morphological alterations produced by zinc deficiency in rat sciatic nerve: a histological, electron microscopic, and stereological study.

Zinc (Zn) is an essential trace element for humans and animals. It is required for normal growth, gene expression, wound healing, protein metabolism, immune function, and membrane integrity. In this study, unbiased stereological methods have been used to quantify the effects of Zn deficiency on the sectioned surface area and the number of myelinated axons in the sciatic nerve of rats. Animals were fed a Zn-deficient or Zn-sufficient diet for a period of 4 weeks. At the end of this time, the samples of sciatic nerves were removed from the animals, processed for electron microscopy and embedded in resin. The Zn-deficient group of rats was found to have a lower body weight compared to rats in the control group (P < 0.05). The sectioned surface area of nerve cross-section and myelinated axon number in Zn-deficient rats decreased by 20% and 29%, respectively, compared to the control group. A significant correlation between sectioned surface area and myelinated axon number was also determined. Morphological findings were as follows: on light microscopy, it was determined that certain abnormalities occur specifically in the experimental group, such as collapsed nerve fascicles, irregular profiles of and degeneration in myelin sheaths, and on electron microscopy, extensive myelin damage was seen in Zn-deficient groups compared with control groups. This study suggests that peripheral nerves require Zn for development and preservation of their structure.

Animals↗

PubMed2005

A simple technique for localizing consecutive fields for disector pairs in light microscopy: application to neuron counting in rabbit spinal cord following spinal cord injury.

Locating the same microscopic fields in consecutive sections is important in stereological analysis. The tools for achieving this requirement have limited number in practice. This paper presents a simple and inexpensive technique for localizing the same fields on disector pairs in conventional light microscopes equipped with widely available dial indicators. It is partly a modification of equipment previously described. The presented procedure requires two light microscopes equipped with dial indicators and modified slide clips. An application of the present system was shown in a model of spinal cord injury (SCI). A midthoracic laminectomy was performed leaving the dura intact. A contusion was done at the level of midthoracic spinal cord segments (T7-T8) by dropping a 10-g mass from a height of 30 cm. The subjects were randomly divided into three groups (10 animals in each): hypothermia group, methylprednisolone group, and traumatic spinal cord injury alone group. Present results show that treatment with hypothermia after spinal cord trauma has a neuroprotective effect on cell damage but not in the methylprednisolone treatment group.

Animals↗

PubMed2002

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

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.

Aging↗