Biomedical subjects

Mustafa F Sargon

Publications and source records attributed to Mustafa F Sargon.

18 recordsLinked to original sources

PubMed2006

Electron microscopic evaluation of the effect of therapeutic silicone hydrogel lenses on the limbal area.

PURPOSE: To investigate the effects of high-permeability silicone hydrogel contact lenses used for therapeutic purposes on limbal cells, inflammation, and neovascularization. METHODS: Bullous keratopathy was induced by injection of 0.05% benzalkonium chloride into the anterior chamber of 20 anesthetized rabbit eyes. Ten-millimeter diameter central epithelial erosions were produced, and silicone hydrogel contact lenses were applied onto 10 corneas. Nasal and temporal tarsorrhaphy was performed to leave the central corneal area open. On the 15th and 30th days, the corneas were extracted and examined under electron and light microscopy. RESULTS: Electron microscopy showed no prominent stress-induced findings in limbal cells in the contact lens group. Epithelial edema was reduced in this group, but on the 30th day, the epithelial edema was greater than that observed on the 15th day. Evaluation of polymorphonuclear and eosinophilic cell infiltration by light microscopy showed that inflammation was less in corneas without contact lenses and the inflammation grade was the same on the 15th and 30th days. Neovascularization was similar in both groups. CONCLUSIONS: The therapeutic use of silicone hydrogel lenses would probably have no effect or, at most, only a slight adverse morphologic effect on limbal area cells. However, when the effects on edema and inflammation were taken into consideration, a 15-day period of wear may be preferable to a 30-day period.

Animals↗

PubMed2005

The efficiency of dexamethasone sodium phosphate-encapsulated chitosan microspheres after cold injury.

OBJECTIVE: The aims of this study were to evaluate the efficiency of dexamethasone sodium phosphate (DSP) in the treatment of cold injury-induced brain edema and to compare systemic and topical application of DSP. METHODS: Sprague-Dawley rats weighing nearly 300 g were used in the experiments. Brain edema was formed by cold injury using metal sterile rods with a diameter of 4 mm that were previously cooled at -80 degrees C. Twenty-four hours after the injury, animals were decapitated and brain tissues were investigated by wet-dry weight method, lipid peroxidation ratio, and histological examination. RESULTS: The degree of edema was significantly lowered in groups in which DSP was administered using chitosan microspheres and by intraperitoneal route (P < .05). The statistical evaluation of the experimental results was performed using Mann-Whitney U test. Histological findings transmission electron microscopy (TEM) correlated with the quantitative results. CONCLUSION: Both intraperitoneal- and microsphere-administered DSP were found to be very effective in a cold injury brain edema model. The authors believe that future studies should lead to new applications of the microsphere formulations prepared by chitosan as the matrix material in many other therapies.

Animals↗

PubMed2005

Electron microscopic study of the progeny of ependymal stem cells in the normal and injured spinal cord.

BACKGROUND: Spinal cord injury (SCI) is a common and often irreversible lesion that can incapacitate patients. Precursor cells in the spinal cord proliferate in response to trauma, and this proliferation can be enhanced by exogenous stimuli such as specific growth factors. In the present study, we examined electron microscopic detection of the proliferation, distribution, and phenotypic fate of these precursor cells in the injured adult rat spinal cord. METHODS: Adult female Sprague-Dawley rats weighing 250 to 300 g were divided into 3 groups. The first group consisted of spinal cord-injured animals with application of a 2.4-g clip extradurally around the spinal cord at the T1 level. A 26-g clip was applied in the second group. The third group included normal uninjured animals. Rats were sacrificed at 3 days, 3 weeks, and 6 weeks after injury. A segment of the spinal cord, 0.4 cm in length, encompassing the injury site was removed and was prepared for electron microscopy. RESULTS: Three days after mild injury (2.4-g clip), ependymal cells had begun to proliferate and had migrated from the central canal. They had a tendency to surround perivascular spaces close to the axons. The central canal rostral to the lesion site was widely dilated at 6 weeks postoperative in the moderately injured groups (26-g clip). The layer of ependymal cells lining the dilated canal showed reduction in cell height. Traumatic syringomyelic cavities were observed in all of the animals. There was an active proliferative response of the ependymal cells to injury. Large clusters of displaced ependymal cells associated with the dilated central canal were observed. Rests of ependymal cells were observed remote from the central canal with a tendency to form rosettes and accessory lumina 6 weeks after trauma. Fascicles of 3 to 8 fibers enclosed within an ependymal cell were a common finding among the ependymal clusters. There were also debris and some ependymal cells in the lumen. CONCLUSION: Trauma induces active proliferation of precursor cells in the ependymal region. These cells may replace neural tissue lost to SCI and may assist in axonal regeneration.

Animals↗

PubMed2005

Protective effect of erythropoietin on type II pneumocyte cells after traumatic brain injury in rats.

BACKGROUND: The main objective was to evaluate the protective effect of erythropoietin on lung ultrastructure against damage in rats after traumatic brain injury. METHODS: We used forty Wistar-Albino female rats weighing 170-200 gr. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The third group was the trauma group. The fourth and fifth groups were erythropoietin (1000 IU/kg) and vehicle (0.4 mL/rat) groups, respectively. A weight-drop method was used for achieving head trauma. Samples were obtained from pulmonary lobes 24-hour post injury. Lipid peroxidation levels were determined and electron microscopic scoring model was used to reveal the ultrastructural changes. RESULTS: Ultrastructural evaluation revealed pathologic changes in the trauma group compared with the control group (p < 0.05). Lipid peroxidation levels were found to be higher in the trauma group (p < 0.05). Erythropoietin significantly reduced both the ultrastructural pathologic changes and the lipid peroxidation levels in the treatment group (p < 0.05). CONCLUSIONS: Erythropoietin protects the ultrastructure of pneumocyte type II cells against damage after traumatic brain injury.

Animals↗

PubMed2005

Age-related changes in human tendo calcaneus collagen fibrils.

OBJECTIVE: The ruptures of tendo calcaneus often occur between the age of 30-45 years as described by several textbooks. It is also described that some diseases and drugs are said to be responsible in the etiology; however, there are no studies related with the detailed histological structure of collagen fibrils found in the tendon in the age groups of humans. In view thereof, this study was aimed to obtain further information on the etiology and to find an answer regarding the frequency of the ruptures occurring between the age of 30-45 years in humans. METHODS: In the study, the biopsy specimens taken from 28 patients (ages 1-68 year) who had undergone surgery due to tendo calcaneus ruptures or achilloplasty operation were examined by transmission electron microscope. All the specimens were prepared according to routine electron microscopic tissue preparation technique. The patients were divided into 7 age groups (1-9, 10-19, 20-29, 30-39, 40-49, 50-59, >60 years) and there were 4 patients in each group. The transverse diameters of collagen fibers were measured from the ultra thin sections and statistical analysis of the results were performed. The study was carried out in the electron microscopy laboratory of the Anatomy Department of Hacettepe University, Ankara, Turkey between January 2004 and September 2004. RESULTS: The diameters of the collagen fibers were higher in the 20-29 year-old group compared to other groups and it showed a statistically significant difference. In patients who were in the 30-39 year-old group or older, the diameters of the collagen fibers were lesser than the 20-29 year-old group. However, an increase was observed in the collagen fibril concentration of these groups. In examination of the specimens of patients who were under 20-year-old, the diameter of the collagen fibers were less than the 20-29 year-old group. The electron microscopic appearance of the tissue sample of a one-year-old patient had a specific organization and in this patient, both the diameters and concentration of collagen fibers were less. CONCLUSION: We believe that the decrease in the diameters of collagen fibers of 30-45 year-old patients who are in the active period of their life, can play a role in the etiology of the frequency of tendo calcaneus ruptures similar to other etiologic factors.

Achilles Tendon↗

PubMed2004

Vascular pedicles of infrahyoid muscles: an anatomical study.

This study was designed to determine the entering sites of vascular pedicles of the infrahyoid muscles. The neck regions of 12 cadavers were investigated bilaterally. The vascular pedicles of the infrahyoid muscles (except the thyrohyoid and inferior belly of the omohyoid muscle) were dissected and measurements taken with a caliper in reference to the attachments of the muscles. For the sternothyroid muscle, two vascular pedicles were found bilaterally in all cadavers. Two vascular pedicles were found bilaterally for the sternohyoid muscle in 11 cadavers; in one cadaver the inferior vascular pedicle was absent bilaterally. One vascular pedicle was found bilaterally for the superior belly of the omohyoid muscle in all cadavers. These data regarding the vascular pedicles of the infrahyoid muscles might be useful for preserving the vascular supply of the infrahyoid muscles during flap preparation.

Adult↗

PubMed2004

Harvesting techniques affect the integrity of the radial artery: an electron microscopic evaluation.

BACKGROUND: Four methods of radial artery harvesting were evaluated with transmission electron microscopy and tissue lipid peroxidation to determine the degree of damage to the artery. METHODS: Radial artery samples from 4 groups of patients (10 samples from each group) who underwent coronary artery surgery were evaluated. In groups I and II, radial arteries were stored in a solution containing 100 mL patients' own heparinized oxygenated blood and 5 mg nitroglycerine. The grafts were distended in group II. In groups III and IV, side branches of the grafts were occluded and left in situ until the coronary anastomosis. In group III, the distal end of the graft was also occluded, while in group IV, both ends were open. RESULTS: The least degree of endothelial damage and disruption of arterial wall integrity were in group IV according to electron microscopic evaluation. The grafts in group III were relatively in good condition compared to groups I and II. Tissue lipid peroxidation was also lowest in group IV. Tissue lipid peroxide levels correlated with ischemic preservation period of the radial artery (r = 0.426). Total semiquantitative transmission electron microscopic scores of the radial artery samples correlated with the lipid peroxide levels (r = 0.581) and ischemia times (r = 0.734). CONCLUSIONS: All arterial grafts, including the radial artery that will be used for coronary artery surgery should not be left ischemic during harvesting to prevent endothelial damage. Ischemia of the conduits for coronary artery grafting can be prevented by leaving them in their anatomic position until the distal coronary artery anastomosis.

Adult↗

PubMed2004

Ultrastructural changes in pneumocyte type II cells following traumatic brain injury in rats.

OBJECTIVE: We aimed to demonstrate the time-dependent ultrastructural changes in pneumocyte type II cells following brain injury, and to propose an electron microscopic scoring model for the damage. METHODS: Forty Wistar-Albino female rats weighing 170-200 g were used. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The others were trauma groups. Weight-drop method was used for achieving head trauma. Samples were obtained from the right and left pulmonary lobes at 2-, 8-, and 24-h intervals after transcardiac perfusion. An electron microscopic scoring model was used to reveal the changes. RESULTS: There were no ultrastructural pathological findings pointing to lung injury in any rat of the control groups. There was intense intracellular oedema in type II pneumocyte and interstitial oedema in the adjacent tissue in trauma groups. Oedema in mitochondria and dilatation in both smooth endoplasmic reticulum and Golgi apparatus was more evident in the 8- and 24-h trauma groups. The chromatin dispersion was disintegrated in the nucleus in all trauma groups. Scores of all trauma groups were significantly different from the controls (P<0.05). All trauma groups were different from each other at significant levels (P<0.05 for each trauma groups). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 h and deteriorates with time. The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation. Further experiments are needed to determine the exact outcome after brain death model.

Animals↗

PubMed2004

Ultrastructural changes in tracheobronchial epithelia following experimental traumatic brain injury in rats: protective effect of erythropoietin.

BACKGROUND: We aimed to demonstrate the time dependent ultrastructural changes in tracheobronchial epithelia after traumatic brain injury. And also, protective effect of erythropoietin was demonstrated. METHODS: We used 56 Wistar-Albino female rats weighing 170 to 200 g. The rats were allocated into 7 groups. First group was the control. The second underwent craniotomy without trauma. The third, fourth, and fifth groups were respectively 2-, 8-, and 24-hour trauma groups. The sixth and seventh groups were respectively treatment (erythropoietin, 1,000 IU/kg) and vehicle (0, 4 ml/rat) groups. Weight-drop method was used for achieving head trauma. Samples were obtained from both trachea and main bronchi. Modified electron microscopic scoring model was used to reveal the ultrastructural changes in both trauma and treatment groups. RESULTS: There was no statistical difference between control and sham groups (p >0.05). Scores of all trauma groups were significantly different from the controls (p <0.05). Trauma produced obvious gradual damage on ultrastructure of the tracheobronchial epithelia. Erythropoietin decreased tracheobronchial scores after traumatic brain injury in significant levels. Erythropoietin attenuated ultrastructural scores for each organelle in significant levels (p <0.05 for each organelle). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 hours deteriorating with time. Erythropoietin protects epithelia against damage after traumatic brain injury. Pharmaceutical lung preservation may help gaining efficacious donor lungs in brain death. But, further time dependent experiments are needed to determine the liability of the donor lung after traumatic brain injury. This fact is to be known for achieving higher graft survival rates.

Animals↗

PubMed2004

Ultrastructural changes of rat cardiac myocytes in a time-dependent manner after traumatic brain injury.

We suggest an ultrastructural scoring system to evaluate the degree of damage in a time-dependent manner in cardiac myocytes after traumatic brain injury (TBI). Forty Wistar-Albino female rats weighing 170-200 g were randomly allocated into five groups. Group 1 was the control and Group 2 was the sham-operated group. Group 3, Group 4 and Group 5 were trauma groups. Weight-drop technique was used for achieving TBI. Lipid peroxidation was estimated by thiobarbituric acid test. An electron microscopic scoring model was used to grade the subcellular changes. Results of heart injury score (HIS) showed that the 24-h trauma group had statistically significant levels in nuclear damage compared with the other groups (p < 0.05). Sarcoplasmic reticulum and mitochondria scores of all trauma groups were significantly different from the control and sham groups (p < 0.05). The results showed that lipid per oxidation levels were statistically significant different between the control and all trauma groups (p < 0.05). The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation levels. Traumatic brain injury produced obvious gradual damage on the ultrastructure of the cardiac myocytes and this damage was more significant in the 24-h trauma group.

Animals↗

PubMed2003

Age-related changes in human PCLs: a light and electron microscopic study.

No studies have previously compared ultrastructural differences in human posterior cruciate ligaments in different age groups, but such differences may be of importance in the reconstruction of this ligament. We used light and transmission electron microscopy to compare ultrastructural differences in the posterior cruciate ligaments of 36 patients by age and sex. We found no differences between the sexes or in the groups aged between 30 and 59 years. However, collagen fibers with variable diameters were observed in those aged 10-19 years, with many oxytalan fibers between the collagen fibers. We also found a decrease in collagen fiber diameter and increase in collagen fibril concentration with aging, with a maximum increase in collagen fibril concentration in those aged 60-69 years.

Adolescent↗

PubMed2003

Placental microcirculation of intrauterine growth retarded fetuses: scanning electron microscopy of placental vascular casts.

AIM: The aim of this study is to investigate the ultra structural difference of placentas in IUGR fetuses that were all found to have abnormal umbilical artery Doppler waveforms. METHODS: Nine placentas from 7 IUGR fetuses and 2 from healthy normal fetuses were evaluated by scanning electron microscopy. RESULTS: All of the placentas of IUGR fetuses who had abnormal umbilical artery Doppler flow antenatally were found to have a prominent increase in the amount of total blood vessels; these aberrant blood vessels had a very tortuous course and they showed increased branching when compared with placentas from uncomplicated term pregnancies. CONCLUSIONS: Our study showed that there is a clear difference in vascular ultra structure of the placentas of pregnancies with fetal growth restriction selected by abnormal umbilical artery Doppler flow test. IUGR seems to be a problem due to placental vascular insufficiency.

Adult↗

PubMed2003

The spinoglenoid ligament: an anatomic study.

The spinoglenoid ligament and its anatomic variations are described in 27 shoulders from 15 cadavers. In each shoulder one or two distinct spinoglenoid ligaments originated from the base of the spine of the scapula; they inserted on the neck of the scapula or the shoulder joint capsule. In the 19 shoulders in which only one spinoglenoid ligament was present, it inserted into the neck of the scapula in 14 cases and into the shoulder joint capsule in five instances. In the eight shoulders in which there were two ligaments, one inserted into the neck of the scapula and the other into the shoulder joint capsule. We did not observe any hypertrophic spinoglenoid ligaments that may have compressed the suprascapular nerve.

Cadaver↗

PubMed2003

Three-dimensional structure of the modiolus. A computerized reconstruction study.

OBJECTIVE: Modiolus is a dense, compact, mobile fibromuscular structure, reachable by the dissection of buccolabial musculature. We undertook this study to provide detailed information about the macroscopic and microscopic anatomy of modiolus and its 3-dimensional (3-D) shape. METHODS: Fifteen micrometer thick serial sections were taken from the fixed cadaveric tissue samples and then stained with hematoxylin and eosin, and Massons' trichrome stain. Stained sections were photographed digitally and images were transferred to computer medium to perform 3-D reconstruction. The study was carried out in the dissection lab of the Anatomy Department of Hacettepe University, Ankara, Turkey between 2002 and 2003. RESULTS: The modiolus appears to be a tortuous, blunt conelike structure, extending vertically from the buccal mucosa to the dermis of the skin. The base of the cone is adjacent to the mucosa. CONCLUSION: As the structure has great clinical importance, and satisfactory complete 3-D analysis of the subject is not yet available; we believe that our study presenting the histological and 3-D description of the modiolus will be of great help to surgeons for satisfactory esthetic and functional results during surgical operations related to the oral commissure.

Adult↗

PubMed2003

Light and electron microscopic examination of human subungual tissue. Glomus and lamellated bodies.

OBJECTIVE: There is only limited data related to the subungual glomus body. We therefore studied the structure of this organ, aiming to obtain further evidence. Additionally, we encountered undefined receptor like structures in close association with these glomus cells, named them as lamellated bodies and examined both of the structures at light and electron microscopic levels. METHODS: This study was carried out at the Faculty of Medicine, Hacettepe University, Ankara, Turkey, during the time period May 2001 to March 2002. In this study, the subungual tissues of 4 patients were examined. RESULTS: Within subungual tissue, 2 groups of morphologically significant structures were determined by light microscopy. The first structure was described as glomus body. It was characterized as an encapsulated structure, rich in rounded clear cells filling its central compartment. The latter structure having a lamellated appearance was described as lamellated body. In the electron microscopic examination, lamellated bodies were characterized by central filament rich large cells and surrounding cytoplasmic processes of ensheathing cells, some of which were vacuolated. Glomus bodies were surrounded by a capsule and centrally located numerous rounded cells which reflected the structural features of an active cell. CONCLUSION: The lamellated bodies are very unusual structures and they are not found in any other part of the body. The structural organization of the ensheathing cells in the lamellated bodies greatly resembles many skin associated receptors. Therefore, we planned future studies by using immunohistochemistry, to reveal nervous elements for structural contribution.

Adult↗

PubMed2002

The effects of topical L-arginine and Ng-nitro-L-arginine methyl ester after experimental acute spinal cord injury. A light and electron microscopic study.

The primary objective of this study was to investigate the effects of topical L-arginine and Ng-nitro-L-arginine methyl ester vs the role of ischemia in contributing to secondary injury after experimental acute spinal cord trauma. Twenty-six rabbits were submitted to spinal cord compression at the T7/8 level. The animals were divided into three groups: no applied drug (n=6), L-arginine (n=10), and Ng-nitro-L-arginine methyl ester (n=10). L-arginine was topically administered at a dose of 10 micromol (1.742 mg) per kg immediately after acute spinal cord injury. Ng-nitro-L-arginine methyl ester was applied topically at a dose of 10 pmol (10 mg/kg) immediately after acute spinal cord injury. Cortical somatosensory evoked potentials were recorded before injury and 1 min, 15 min, 30 min, and 60 min after injury. Physiological parameters were followed before, during, and I h post injury. Light and electron microscopic analysis was performed in all of the groups. In contrast to group 1, the edema of perineural, axoplasm, or surrounding tissue, the thickening of walls of the arterioles and venules, and the degeneration in myelinated axons in groups 2 and 3 were well observed. However, no differences between group 2 and group 3 occurred.

Administration, Topical↗

PubMed2002

Distinct intergender difference in the femoral artery ramification patterns found in the Turkish population: angiographic study.

Using 600 bilateral femoral angiographies (300 male lower extremities and 300 female lower extremities), we observed configurations of the femoral origins of the medial circumflex femoral artery (MCFA), lateral circumflex femoral artery (LCFA) and the deep femoral artery. The distinct intergender difference was found in the incidence of direct origin of the MCFA from the femoral artery (17.8% and 80.0% in male and female limbs, respectively). The LCFA also exhibited a marked difference between genders in the incidence of direct origin. The Turkish population seemed to be characterized by an intergender difference in specific somatic arterial morphology.

Adult↗

PubMedDate not supplied

Development and brain delivery of chitosan-PEG nanoparticles functionalized with the monoclonal antibody OX26.

The inhibition of the caspase-3 enzyme is reported to increase neuronal cell survival following cerebral ischemia. The peptide Z-DEVD-FMK is a specific caspase inhibitor, which significantly reduces vulnerability to the neuronal cell death. However, this molecule is unable to cross the blood-brain barrier (BBB) and to diffuse into the brain tissue. Thus, the development of an effective delivery system is needed to provide sufficient drug concentration into the brain to prevent cell death. Using the avidin (SA)-biotin (BIO) technology, we describe here the design of chitosan (CS) nanospheres conjugated with poly(ethylene glycol) (PEG) bearing the OX26 monoclonal antibody whose affinity for the transferrin receptor (TfR) may trigger receptor-mediated transport across the BBB. These functionalized CS-PEG-BIO-SA/OX26 nanoparticles (NPs) were characterized for their particle size, zeta potential, drug loading capacity, and release properties. Fluorescently labeled CS-PEG-BIO-SA/OX26 nanoparticles were administered systemically to mice in order to evaluate their efficacy for brain translocation. The results showed that an important amount of nanoparticles were located in the brain, outside of the intravascular compartment. These findings, which were also confirmed by electron microscopic examination of the brain tissue indicate that this novel targeted nanoparticulate drug delivery system was able to translocate into the brain tissue after iv administration. Consequently, these novel nanoparticles are promising carriers for the transport of the anticaspase peptide Z-DEVD-FMK into the brain.

Animals↗