Biomedical subjects

Seda Vatansever

Publications and source records attributed to Seda Vatansever.

11 recordsLinked to original sources

PubMed2006

Histopathological and ultrastructural effects of glycolic acid on rat skin.

Use of alpha hydroxy acids (AHA) to ameliorate specific dermatological problems with keratinization has become fairly widespread. The aim of this study was to evaluate the effects of the AHA derivative of glycolic acid, applied in different dosages, on rat skin using light and electron microscopy. Skin biopsies were taken from the dorsal side of rats (n=16) and at the end of each week after applying solutions containing AHA: week 1, 8% (n=5); week 2, 50% (n=5); week 3, 70% (n=6). The skin samples were fixed in 10% formalin for histology and 2.5% glutaraldehyde solution for electron microscopy and processed using routine protocols. Histological sections were stained with hematoxylin and eosin (H&E), Masson's trichrome and were also labelled for binding of a primary antibody against collagen I using the avidin-biotin-peroxidase method. The epidermal thicknesses were measured and the fibroblast count of the dermis was taken and the results compared using the statistical ANOVA test. Semi-thin sections were stained with toluidine blue-azure II solution and ultrathin sections were contrasted with uranyl acetate and lead citrate. Histochemical and immunohistochemical observations demonstrated that AHA treatment resulted in statistically significant increased thickness of the epidermis and an increase in numbers of active fibroblasts and in the amount of dense collagen, especially at higher dosages of AHA. Ultrastructural examination of rat skin from AHA-treated groups showed cytoplasmic vacuolization in epidermal keratinocytes, intercellular dysjunctions, and increased quantities of organized bundles of collagen fibers in the dermis. The use of AHA in appropriate dosages has been found to play an important role in the treatment of specific skin disorders, however, the harmful effects of use of AHAs at higher concentrations should not be ignored. We conclude that alpha hydroxyl acids have a wide spectrum of use in the field of dermatology but, due to side-effects, their use, dosage, and time frame should be restricted to the advice of dermatologists.

Animals↗

PubMed2006

The role of ATP sensitive K+ channels and of nitric oxide synthase on myocardial ischemia/reperfusion-induced apoptosis.

During ischemia, ATP-sensitive K+ channels (KATP channels) open, and this triggers necrotic processes and apoptosis. In this study, we investigated whether selective sarcoplasmic and mitochondrial KATP channel blockers affected myocardial apoptosis and nitric oxide synthase (NOS) activity in a rat model of myocardial ischemia/reperfusion in vitro. Isolated rat hearts were subjected to 30 min of coronary artery occlusion followed by 30 min of reperfusion. A selective sarcKATP channel blocker, HMR1098 and a selective mitoKATP channel blocker, 5-hydroxydecanoate, were added to the perfusion fluid 10 min before occlusion. Myocardial apoptosis was detected immunohistochemically using the TUNEL method. Myocardial inducible NOS (iNOS) and endothelial NOS (eNOS) were determined immunohistochemically. In control hearts, apoptosis induction was associated with a greater immunoreactivity of iNOS than eNOS. Treatment with HMR1098, at a concentration of 3 micromol/l, significantly reduced the TUNEL-positive cardiomyocytes and this was associated with decreased iNOS and increased eNOS immunoreactivity. When this drug was administered at a higher concentration, at 30 micromol/l, a more marked reduction in apoptosis was observed but, in contrast to the effects observed at the lower drug concentration, eNOS immunoreactivity was almost completely abolished while iNOS was strong. Moreover, ischemia-induced cardiac dysfunction (e.g. contractile force and recovery of coronary flow) was increased by the higher concentration of HMR 1098. In hearts treated with 5-hydroxydecanoate, myocyte apoptosis was slightly reduced, and this was associated with an almost equal increase in both iNOS and eNOS immunoreactivity. These findings suggest that iNOS appears to be more important than eNOS in the reduction of apoptosis. However, the further inhibition of apoptosis by the higher concentration of HMR 1098 was associated with poorer cardiac function.

Animals↗

PubMed2006

Effect of portal vein occlusion on the pancreas: an experimental model.

BACKGROUND: The effects of portal vein occlusion on the pancreas are not clearly understood. Therefore, we studied histomorphological changes induced in the rat pancreas by various periods of portal vein occlusion. MATERIALS AND METHODS: Sixty female Wistar albino rats were randomly allocated into four groups of 15 each. In Group I (control), rats underwent sham laparotomy to expose the portal vein proximal to its bifurcation. In Groups II-IV, rats underwent laparotomy followed by portal vein occlusion by clamping for 15, 30, and 60 minutes respectively. The pancreas was removed immediately after sham laparotomy in Group I and immediately after clamp release in Groups II-IV. Pancreatic tissue specimens were subjected to histochemical analysis for cell typing and diagnosis, immunohistochemical analysis for identification of the inflammatory markers tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), endothelial nitric oxide synthase (eNOS), and inducible NOS (iNOS), and TUNEL analysis was carried out for identification of apoptotic cells. RESULTS: Histochemistry revealed signs of inflammation in pancreatic tissue from rats subjected to portal vein occlusion. Immunohistochemistry revealed that the expression of proinflammatory cytokines TNF-alpha and IL-1beta and the oxidative damage indicator iNOS in rat pancreatic tissue increased progressively with the duration of portal vein occlusion. TUNEL assay revealed no signs of apoptosis in any of the groups. CONCLUSION: We conclude that portal vein occlusion triggers an inflammatory response in the pancreas that worsens the longer the occlusion lasts.

Animals↗

PubMed2006

Examination of bcl-2 and p53 expressions and apoptotic index by TUNEL method in psoriasis.

BACKGROUND: Psoriasis is characterised by hyperproliferation and by aberrant differentiation. Blockage of the normal apoptotic process is one of the factors implicated in the pathogenesis. OBJECTIVE: To determine the apoptotic features by using TUNEL method and also bcl-2 and p53 expressions in psoriatic epidermis. MATERIALS AND METHODS: Biopsies of 35 patients with psoriasis vulgaris and 14 normal skin were evaluated. Apoptotic cells were detected using the dUTP nick-end labelling assay; bc1-2 and p53 expressions were assessed by using immunohistochemical techniques. A semi-quantitative grading system (HSCORE) was used for comparison. RESULTS: Bcl-2 was strongly expressed in basal keratinocytes of normal skin, while no expression was observed in 13 (37.2%) of the psoriatic samples and it was weakly expressed in the spinous cell layer of 22 (62.8%) samples. Moderate p53 expression was observed in the psoriasis group, while it was weak in the control. The percentage of TUNEL positive cells were significantly increased in the psoriasis group (65+/-2.30) when compared with the control (32.84+/-7.16). CONCLUSION: Apoptotic index besides bc1-2 and p53 expressions in psoriasis differ from normal epidermis. Down-regulation of bc1-2 is consistent with the dynamics of psoriasis but increased TUNEL positive cells and p53 expression has not been fully elucidated yet. Gündüz K, Demireli P, Vatansever S, Inanir I. Examination of bcl-2 and p53 expressions and apoptotic index by TUNEL method in psoriasis.

Apoptosis↗

PubMed2005

The effect of spermatic vessel ligation on testicular nitric oxide levels and germ cell-specific apoptosis in rat testis.

Management of high testis may vary but the most popular method in surgical treatment is the Fowler-Stephens maneuver. The aim of the present study was to investigate the effects of spermatic vessel ligation on testicular nitric oxide (NO) levels, expression of inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) and germ cell-specific apoptosis in both ipsilateral and contralateral testes in rats. Twenty-eight animals were randomly allocated into four groups (n=7 each). The spermatic vessels were ligated as a simulation of the Fowler-Stephens maneuver. The groups of animals were sacrificed at 2 h (group 1), 4 h (group 2) and 24 h (group 3) after ligation, respectively. Sham-operated animals served as controls (group 4). Biochemical assessment of testicular NO levels was performed by the Griess method. iNOS and eNOS expression and apoptosis were studied in ipsilateral and contralateral testes. Testicular NO levels at 24 h after the simulated Fowler-Stephens maneuver were found to be significantly increased in both ipsilateral and contralateral testes when compared with the sham-operated group. eNOS expression was clearly increased in ipsilateral testes, whereas moderate expression was detected in the contralateral seminiferous tubules at 24 h after ligation. Mild focal iNOS immunostaining was also observed in seminiferous tubules of the ipsilateral testis at 24 h after the simulated Fowler-Stephens maneuver. Apoptosis was dramatically increased in ipsilateral testes; however, it was only detected in single cells in the contralateral side at 24 h after ligation. In conclusion, the simulated Fowler-Stephens maneuver induces testicular nitric oxide synthesis and germ cell-specific apoptosis in the ipsilateral testis. These results suggest that high levels of NO induce apoptosis and may impair spermatogenesis thus explaining the unsuccessful outcome of the Fowler-Stephens maneuver.

Animals↗

PubMed2005

Pre-ischemic administration of nitric oxide synthase inhibitors reduced germ cell apoptosis after spermatic vessel ligation in the rat testis.

INTRODUCTION: The Fowler-Stephens maneuver, a mode of spermatic vessel ligation, is a method of choice in the management of high testes. The aim of the present study is to investigate the effects of pre-ischemic administration of N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase (NOS) inhibitor, in preventing testicular ischemic damage and germ cell-specific apoptosis in rats. MATERIALS AND METHODS: 30 min before ligation of the spermatic vessels, L-NAME was administered intraperitoneally to a group of rats and saline was given to another group of rats (controls). Biochemical assessments of NO and germ cell-specific apoptosis were performed. RESULTS: Testicular NO levels in the L-NAME group showed significant decreases in the ipsilateral (p = 0.004) and contralateral (p = 0.015) testes in relation to those of the control group. The apoptotic indices were found in 2.3% of the L-NAME group and 3.1% of the control group. CONCLUSION: Pre-ischemic administrations of the NOS inhibitor, L-NAME, effectively decreased NO production and to some degree caused a reduction in germ cell apoptosis in the rat testes after spermatic vessel ligation. Further studies are mandatory to confirm our preliminary results and to address the potential introduction of NOS inhibitors into clinical practice.

Animals↗

PubMed2004

Neural tissue continues its maturation at the site of neural tube closure defects: implications for prenatal intervention in human samples.

OBJECTIVE: Our objective was to investigate the relation between the embryological development and neural tissue maturation at the site where the neural plate failed to form a neural tube. MATERIAL AND METHODS: Samples from 15 aborted human fetuses with neural tube defects (NTD). All of the fetuses were between 20 and 25 gestational weeks old. Indicators of neural tissue maturation, formation of basal lamina, expression of integrins and neuron specific class III beta tubulin (tuj1) were investigated. To detect the adverse effects of the environment, if any, p53 and bcl-2 activity at both sites of the open and closed neural plate were investigated as well. RESULTS: No difference was found in the expression of maturation-related molecules at the site of the neural plate that remained open compared with the site where the neural tube is normally formed. While high p53 activity was noted in neural tissue at the site of the neural tube defect, no such activity was detected in the neural tissue where the neural tube is normally formed. CONCLUSION: Our results suggested that maturation and differentiation of neural tissue continued regardless of the failure of neural tube closure. Therefore, the neurological deficits that are encountered in NTD patients should be related to secondary damage such as amnion fluid toxicity, uterus contractions, labor, etc. It seems valuable to save the neural plate before the negative effects of the environment renders the neural tissue functionless.

Embryonic and Fetal Development↗

PubMed2003

Tear function changes of postmenopausal women in response to hormone replacement therapy.

OBJECTIVE: The goal of this study was to search the effect of hormone replacement therapy (HRT) on tear function changes in postmenopausal women. METHODS: Following initial ophtalmic evaluation and tear sample collection, the subjects were given daily 0.625 mg conjugated estrogen, and either continuous combined or cyclic 5 mg medroxyprogesterone acetate was added. Eye examination included visual acuity, slit-lamp examination, fundus examination, tonometry, Schirmer's test, and break up time (BUT) evaluation. Six months later, control examination was done and repeat tear samples were obtained. Tear immune globulin A (IgA) and lysozyme levels were measured by gel electrophoresis. The pictures of the bands were evaluated by digital image analysis with Scion Image program. RESULTS: Conjunctival vascular congestion, laxity and corneal desquamation did not change before and after HRT (P>0.05). A significant improvement was noted in meibomian gland inflammation (P=0.034). We have not observed any significant difference in burning, foreign body sensation, and tearing (P>0.05). In addition, no significant difference was noted in BUT (P=0.370) and Schirmer's test values (P=0.271). Though both lysozyme and IgA levels were elevated following the therapy, only IgA levels increased significantly (P=0.04). CONCLUSION: HRT decreased meibomian gland inflammation and increased tear lysozyme and IgA levels in postmenopausal women.

Female↗

PubMed2002

Is a filum terminale with a normal appearance really normal?

INTRODUCTION: Tethered spinal cord is defined as a condition in which the conus medullaris ends at a level below the L1-2 intervertebral space. The spinal cord is considered to be tethered when there is a thick filum terminale or low-lying conus medullaris. It has also been reported that a normal level of the conus medullaris and normal thickness of the filum terminale do not mean that there is no cord tethering. MATERIALS AND METHODS: In this investigation, we examined 21 fila terminalia; 5 of them were taken from cadavers, and these were used as a control group (group 1; n/n), 8 from patients with a normal appearance of the filum terminale but with clinical symptoms (incontinence) and pathologic results of a urodynamic study (group 2; n/ab), and 8 from patients with an abnormal appearance of the filum terminale and with clinical symptoms (group 3; ab/ab). Interestingly, we found that while fila terminalia in the control group were made up mainly of collagen fibers, more connective tissue with dense collagen fibers, some hyalinization and dilated capillaries were noticed in the fila from group 2. RESULTS: Our results suggest that these histological features may reflect a decreased elasticity within the filum terminale, resulting in a tethering effect on the lower conus in otherwise normal physiological conditions. CONCLUSION: These findings lead us to reconsider sectioning of the filum terminale in incontinent patients with normal results in radiological studies, whose condition is called "nonneurogenic neurogenic bladder."

Adolescent↗

PubMed2002

Comparative morphological differences between umbilical cords from chronic hypertensive and preeclamptic pregnancies.

To compare morphological changes in the umbilical cords from chronic hypertensive and preeclamptic patients having normal or pathological umbilical artery Doppler ultrasonographic results. Umbilical cords from 34 normotensive, 31 chronic hypertensive and 70 preeclamptic women with normal and abnormal Doppler flow velocity waveforms (FVW) at 35-40 gestational weeks were studied. Morphological changes in the umbilical cords were examined on formalin-fixed, paraffin-embedded sections. The total umbilical cord area, total vessel area, and wall thickness of umbilical vessels were measured in systematic random samples using unbiased stereology methods. An ANOVA test was used for statistical analysis. In the chronic hypertensive and preeclamptic groups with normal Doppler FVW, the thickness of the umbilical cord vessels remained nearly constant, whereas both the total area and the lumen area were reduced. These changes correlate with the histopathological findings, suggesting a mainly vasoconstrictive effect. By contrast, analysis of the preeclamptic group with pathologic Doppler FVW showed a comparable reduction of all parameters of the umbilical cord. Histopathological findings were related to smaller, contracted smooth muscle cells of the vessel wall, which is suggestive of a predominant hypoplastic mechanism. As a result of reduced uteroplacental perfusion, fetal hypoxia and intrauterine growth retardation become unavoidable in preeclampsia. The histopathological changes in the umbilical cord between the chronic hypertensive and preeclamptic patients depend on the Doppler results. In conclusion, the umbilical artery Doppler FVW indices provide good values for predicting intrauterine growth retardation in preeclamptic patients.

Adult↗

PubMedDate not supplied

The long-term effect of mesh bioprosthesis in inguinal hernia repair on testicular nitric oxide metabolism and apoptosis in rat testis.

Polypropylene mesh is the most widely used material in inguinal hernia repair. Although polypropylene mesh is known as an inert material, it is experimentally proven that mesh generates a chronic inflammatory tissue reaction. The aim of the present study was to investigate the long-term effects of polypropylene mesh material used in inguinal hernia operations on testicular function, testicular nitric oxide (NO) metabolism and germ cell-specific apoptosis in rats. The study comprised 40 male rats that were randomly allocated into two groups. In group 1, the left spermatic cord was elevated and a 0.5 x 1 cm polypropylene mesh was placed behind the left inguinal spermatic cord and group 2 consisted of the sham-operated controls. Blood samples were taken at 6 months preoperatively and postoperatively after to assess luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels for hormonal evaluation. Testicular NO was evaluated by the Griess method, apoptosis by a TUNEL method and inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) expressions by immunohistochemical staining. Mild (+) eNOS expression was observed in all specimens. Mild (+) iNOS expression was only detected in ipsilateral testis of the mesh-implanted study group. Apoptotic cells were not detected in any samples. We are of the opinion that long-term polypropylene mesh implantation has no effect on testicular hormonal function and only a limited effect on nitric oxide levels and this effect is not sufficient to cause apoptosis in testis that could lead to infertility. It seems that mesh implantation is a reliable method in inguinal hernia repair; however, further work is required by more sensitive methods to fully elucidate the potential testicular damage.

Animals↗