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Öğe Cerebrospinal fluid adrenomedullin levels in patients with pre-eclampsia(Blackwell Munksgaard, 2003) Celik, O; Hascalik, S; Yurekli, M; Turkoz, Y[Abstract Not Available]Öğe Cerebrospinal fluid leptin levels in preeclampsia: relation to maternal serum leptin levels(Wiley, 2004) Celik, O; Hascalik, S; Ozerol, E; Hascalik, M; Yologlu, SBackground: To determine whether cerebrospinal fluid (CSF) and circulating levels of leptin differ between women with preeclampsia and women who had an uncomplicated pregnancy. Methods: Maternal serum and CSF leptin concentrations obtained in the third trimester of the gestation were compared in 16 women with mild preeclampsia and 23 normotensive pregnant women who underwent cesarean section. Before administering local anesthetic for spinal anesthesia, 2 mL CSF and 4 mL venous blood sample were taken and were stored at -30 degreesC until serum and CSF leptin levels were measured by enzyme-linked immunosorbent assay (ELISA). Results: Mean CSF leptin concentrations were not significantly different between the two groups (preeclampsia 9.7 +/- 4.2 ng/mL, normotensive 13.6 +/- 4.3 ng/mL, p = 0.952). Similarly, mean serum leptin concentrations were similar between the two groups (mild preeclampsia 21.7 +/- 7.1 ng/mL, normotensive 18.3 +/- 6.7 ng/mL, p = 0.698). CSF leptin levels are inversely related to the serum leptin concentrations in preeclamptic patients (r = -0.87, p = 0.000). An inverse relationship was also detected between CSF and serum leptin levels in normotensive pregnant subjects (r = -0.66, p = 0.000). Conclusions: CSF and serum leptin levels were similar in patients with preeclampsia and normotensive pregnant women. However, the CSF leptin was negatively correlated with the serum leptin concentrations in preeclamptic and normotensive control subjects, suggesting that leptin enters the brain by a saturable transport system. Further work is needed to confirm our findings.Öğe Cerebrospinal fluid nitric oxide level changes in preeclampsia(Elsevier Sci Ireland Ltd, 2003) Celik, O; Hascalik, S; Turkoz, Y; Hascalik, M; Gokdeniz, RObjective: The purpose of this study was to determine the level of nitric oxide (NO) metabolites, nitrite and nitrate in human cerebrospinal fluid (CSF) and serum and to assess whether there is any relationship among CSF, serum nitrate-nitrite levels and preeclampsia. Study design: Twenty-one preeclamptic and 27 healthy pregnant women as control group who underwent cesarean section (C/S) were included in the study. Before administering local anesthetic for spinal anesthesia, 2 ml CSF and 4 ml venous blood sample were taken. CSF and serum total nitrite, direct nitrite and nitrate levels were determined spectrophotometrically. Results: CSF total nitrite, direct nitrite and nitrate levels were significantly different between the two groups (21.00 +/- 1.68, 8.28 +/- 0.89 and 12.71 +/- 1.08 mumol/l, respectively versus 15.53 +/- 1.49, 5.57 +/- 0.39 and 9.96 +/- 1.45 mumol/l, respectively, P < 0.05). Significantly higher serum nitrate level was found (31.84 +/- 2.31 mumol/l) in the control group compared to the preeclamptic group serum nitrate level (25.06 +/- 2.02 mumol/l). Statistical comparisons were performed by the Mann-Whitney U-test. Conclusion: CSF-NO is significantly higher but serum NO is lower in preeclamptic group compared with control group may suggest independent regulation of NO in the two compartments. The determination of CSF-NO metabolites could be useful to clarify whether increased NO production is predominantly associated with poor perfusion of the brain in preeclampsia. (C) 2003 Elsevier Ireland Ltd. All rights reserved.Öğe cFN and NO levels as indexes of endothelial damage in pre-eclampsia(Elsevier Sci Ireland Ltd, 2003) Celik, O; Hascalik, S; Turkoz, Y[Abstract Not Available]Öğe Clinical significance of N-acetyl-L-aspartate resonance in ovarian mucinous cystadenoma(Lippincott Williams & Wilkins, 2006) Hascalik, S; Celik, O; Sarac, K; Alkan, A; Mizrak, BMagnetic resonance spectroscopy (MRS) provides a noninvasive measurement of the biochemistry of living tissue. We report spectroscopy analysis of a 26-year-old woman affected by right ovarian lesion diagnosed as mucinous cystadenoma. MRS was performed by the point-resolved spectroscopy technique with a long echo time (TE) (136 msec). MRS measurements were performed on the two distinct component of the right ovarian tumor. The classification of metabolite peaks area in this study was performed according to the technique described by Okada et al. The features of proton MRS studies are discussed. As well as strongly elevated lactate and N-acetyl-L-aspartate signals, the tumor spectrum showed lipid resonances. Proton MRS imaging may be helpful for the investigation of the underlying pathophysiology of ovarian mucinous cystadenomas.Öğe Clip Turcica: a new apparatus for experimental ovarian ischemia and reperfusion model in rats(Elsevier Science Inc, 2005) Hascalik, S; Celik, O; Turkoz, Y; Mizrak, BClip Turcica is a unique, malleable, aluminum that facilitates holding and release of the adnexa during a period of experimental ovarian ischemia and reperfusion, without anesthesia and laparotomy. The simple opening and closing mechanism of the Clip Turcica allows easier, quicker, and safer application compared with previous methods. (c) 2005 by American Society for Reproductive Medicine.Öğe Effect of electromagnetic field emitted by cellular phones on fetal heart rate patterns(Elsevier Sci Ireland Ltd, 2004) Celik, O; Hascalik, SThe study was planned to determine the effects of electromagnetic fields produced by cellular phones on baseline fetal heart rate, acceleration and deceleration. Forty pregnant women undergoing non-stress test were admitted to the study. Non-stress test was obtained while the subjects were holding the CP on stand by mode and on dialing mode, each for 5 min. Similar recordings were taken while there were no phones around for 10 min. Electromagnetic fields produced by cellular phones do not cause any demonsterable affect in fetal heart rate, acceleration and deceleration. (C) 2003 Elsevier Ireland Ltd. All rights reserved.Öğe Effects of resveratrol, raloxifene, tibolone and conjugated equine estrogen on vaginal squamous cell maturation of ovariectomized rats(Karger, 2005) Hascalik, S; Celik, O; Tamser, M; Mizrak, BObjective: The effects of estrogen replacement therapy, selective estrogen receptor modulators, or tibolone on vaginal squamous cell maturation in postmenopausal women are not well established. Resveratrol ( 3,5,4'- trans - trihydroxystilbene) has been shown to bind the estrogen receptor in rat uteri. The aim of this study was to cytologically evaluate vaginal smears from ovariectomized rats treated with resveratrol, raloxifene, tibolone and conjugated equine estrogen, and to compare each drug with regard to vaginal epithelial maturation. Material and Methods: Forty-two bilaterally ovariectomized Wistar albino rats were equally randomized into 6 groups: ( 1) control sham-operated rats; ( 2) ovariectomized rats administered 0.1% ethanol; ( 3) ovariectomized rats administered resveratrol at a dose of 5 mg/kg/day p. o.; ( 4) ovariectomized rats administered conjugated equine estrogen (CEE) at a dose of 0.1 mg/kg/day p. o.; ( 5) ovariectomized rats administered tibolone at a dose of 0.25 mg/kg/ day p.o., and ( 6) ovariectomized rats administered raloxifen at a dose of 1 mg/kg/day p. o. Administration of drugs started 5 days after bilateral ovariectomy and continued for 35 days. After 35 days of treatment a vaginal smear was obtained from each rat. Smears were stained with the usual Papanicolaou method, and observed with a light microscope by an experienced cytopathologist. Cytological grading was made according to the extent of parabasal, intermediate, superficial and anuclear squamous cells. Results: Ovariectomized rats had lower scores for superficial and anuclear cells when compared to sham-operated rats ( p < 0.05). The CEE group had higher scores for superficial and anuclear cells than those of the ovariectomized, raloxifene and tibolone groups ( p < 0.05). The resveratrol-treated rats had higher scores for superficial cells but lower scores for parabasal cells than ovariectomized rats ( p < 0.05). The raloxifene and tibolone groups had the same scores for intermediate, superficial and anuclear cells but lower scores for parabasal cells compared to ovariectomized rats. Conclusion: The results of our study suggest that resveratrol offsets the reduction in vaginal stratification generally observed after oophorectomy. Copyright (C) 2005 S. Karger AG, Basel.Öğe In vivo proton magnetic resonance spectroscopy in the evaluation of the endometrium(Wiley, 2004) Sarac, K; Celik, O; Hascalik, S; Alkan, A; Mizrak, BBackground The purposes of this study were to compare proton magnetic resonance (MR) spectroscopic evaluation of the endometrium with histology obtained by endometrial biopsy in women undergoing diagnostic curettage and to determine whether screening with MR spectroscopy (MRS) might be useful in the evaluation of the endometrium. Methods. Twenty-three consecutive women who were scheduled for endometrial biopsy were included in the study. The women were evaluated by MRS, performed immediately before the endometrial biopsy. The MRS results were compared with the histological findings obtained from the endometrial biopsy. Results. All of the cases were proven by pathological examination, and their diagnoses were secretory endometrium (I I cases), proliferative endometrium (seven cases) and disordered proliferative endometrium (five cases). The characteristically obtained signals of choline (Cho) and lipid were detected in all subjects in the secretory endometrium group. In the same group, eight patients showed lactate signals and six showed creatine (Cr) signals. In the disordered proliferative endometrium group, four patients showed lipid plus Cho signals. Two patients in the same group demonstrated both lactate and Cr signals. All patients in the proliferative endometrium group showed Cho signals, two patients demonstrated lactate plus Cho signals, and none of the patients in this group showed lipid and Cr signals. Conclusion. Proton magnetic resonance spectra can register certain metabolic differences in human endometrium in its different stages.Öğe Influence of misoprostol (PGE1) on amniotic fluid and maternal serum adrenomedullin levels(Wiley, 2005) Hascalik, S; Celik, O; Dogru, MI; Dogru, AK; Inan, E; Yurekli, MObjective. The purpose of this study was to determine the levels of adrenomedullin (AdM) in amniotic fluid (AF) and maternal serum of misoprostol (PGE1)-induced pregnant women. Materials and methods. A total of 40 women were included in the study: 20 were in active labor and were delivered vaginally and a further 20 were not in labor and misoprostol induction was performed. Women who were undergoing labor induction received 50 mu g of misoprostol, which was placed in the posterior fornix of the vagina every 4 hrs until the onset of labor. In each patient, maternal plasma and AF samples were collected. Samples of AF were collected by transvaginal route at the time of rupture of the membranes. The labor was at the same stage in both the groups during the sample collection. In all pregnant subjects, maternal blood samples were drawn from the cubital vein at the time of AF sampling. Amniotic fluid and serum AdM concentration was measured by using reverse-phase high-performance liquid chromatography. Results. Misoprostol-induced pregnant women showed significantly higher AdM concentrations than control pregnant women in AF (79.48 +/- 6.14 pmol/ml versus 21.28 +/- 0.90 pmol/ml, P = 0.000) and maternal serum (88.20 +/- 4.34 pmol/ml versus 29.78 +/- 4.51 pmol/ml, P = 0.000). There was no significant difference between maternal serum and AF-AdM concentrations in misoprostol and control subjects. Conclusion. Increased serum and AF-AdM concentrations may be necessary to initiate cervical ripening in misoprostol-induced pregnant women.Öğe Magnetic resonance spectral analysis of ovarian teratomas(Elsevier Ireland Ltd, 2005) Hascalik, S; Celik, O; Erdem, G[Abstract Not Available]Öğe Magnetic resonance spectroscopic comparison of the effects of resveratrol (3,4',5-trihydroxy stilbene) to conjugated equine estrogen, tibolone and raloxifene on ovariectomized rat brains(Elsevier Science Bv, 2005) Celik, O; Erdem, G; Hascalik, S; Karakas, HM; Tamser, MObjective: To investigate the effects of resveratrol on basic cerebral metabolites of in the brains of ovariectomized rats. Materials and methods: Twenty-four bilaterally ovariectomized rats were randomly assigned into six groups With four rats in each group. The groups consisted of sham-operated (control), ovariectomized, resveratrol, conjugated equine estrogen (CEE), tibolone and raloxifene treated rats. Drug administration started at the 5th day following ovariectomy and continued for 35 days. At the end of the entire Course, in vivo single vowel magnetic resonance spectroscopy was performed on whole brains to determine choline, creatine and N-acetyl aspartate (NAA) concentrations. Results: Compared to sham-operated group, ovariectomized group had significantly lower NAA (P < 0.008) but significantly higher choline levels (P < 0.031). Administration of CEE and resveratrol resulted in NAA levels that were similar to those in the sham-operated group, showing that the NAA decrease due to ovariectomy was prevented. Treatment with tibolone and raloxifene resulted in a smaller increase in NAA and the effect failed to reach significance. Administration of resveratrol, CEE, tibolone and raloxifene resulted in choline levels similar to those in sham-operated group, showing that the increase in the ovariectomy group was prevented. Conclusion: Resveratrol causes levels of cerebral metabolites that is similar to conventional hormone replacement agents. This finding may suggest that neuronal function in the postmenopausal state was preserved. More detailed investigation of this issue should be the task of future research. (c) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Magnetic resonance spectroscopy features of uterine leiomyomas(Karger, 2004) Celik, O; Sarac, K; Hascalik, S; Alkan, A; Mizrak, B; Yologlu, SObjective: The purpose of this study is to investigate the in vivo magnetic resonance spectroscopy features of uterine leiomyomas using long echo time and to characterize the spectral patterns of these lesions. Methods: We calculated metabolites in 15 patients with uterine leiomyomas and myometrium of 20 healthy control subjects using single-voxel proton MR spectroscopy (point resolved spectroscopy technique, TE:136 ms). Voxels were placed at the center of the uterine leiomyomas. The peak areas of creatine, choline, lipid and lactate were determined. The MR spectroscopy results of uterine leiomyomas were compared with the spectroscopy results obtained from the myometrium of healthy control subjects. Results: The characteristically obtained signal was choline, which was detected not only in 14 of the 15 leiomyomas (93.3%) but also in 18 of the 20 myometrium of control subjects (90%). The lipid signals were determined in 9 of 15 patients with uterine leiomyomas (60%) and 8 of 20 control subjects (40%). The lactate signal was obtained from six of 15 patients with leiomyomas (40%) but only two of myometrium (10%). The creatine signal was obtained from 4 of 15 patients with leiomyomas (26.6%) and 5 of 20 myometrium (25%). Among the tested parameters only lactate peak was statistically significant (p < 0.05). Conclusion: Proton MR spectroscopic imaging may be helpful for the investigation of the underlying pathophysiology of uterine leiomyomas. The presence of lactate and lipid signals in the spectrum may be a useful indicator of metabolic pathway of uterine leiomyomas. Copyright (C) 2004 S. Karger AG, Basel.Öğe Magnetic resonance spectroscopy of premalignant and malignant endometrial disorders: a feasibility of in vivo study(Elsevier, 2005) Celik, O; Hascalik, S; Sarac, K; Meydanli, MM; Alkan, A; Mizrak, BObjective: To assess the potential clinical utility of in vivo proton magnetic resonance spectroscopy (MRS) in patients with various endometrial lesions. Methods: Twelve patients with untreated uterine bleeding were included in this study. In-vivo proton MRS was performed using a 1.5 T MR scanner. The metabolite levels were classified into three classes in comparison with the noise level by visual examination. All the patients have endometrial biopsy. For each type of lesions, chemical compound were described. Results: Pathological examination resulted in three endometrial cancer, two simple hyperplasias, one complex hyperplasia, two partial hydatiform mole, two proliferative endometrium and two secretory endometrium. In women with endometrial carcinoma, high choline and lipid signals were detected, whereas no creatine and no lactate signals were found. In women with endometrial hyperplasia, choline signal was detectable in all cases but one case showed lactate signal in addition to choline. In women with partial hydatidiform mole, the only detectable signal was choline. Lipid signals were detected in none of the cases with endometrial hyperplasia and partial hidatidiform mole. In women with either secretory or proliferative endometrium, choline and lactate signals were detectable in all cases but one case showed solely choline. Lipid signals were not deteced in any of subjects with secretory or proliferative endometrium. Conclusion: The observed difference is the presence of lipid signal only in endometrial carcinoma. (C) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Melatonin reduces torsion-detorsion injury in rat ovary: biochemical and histopathologic evaluation(Wiley, 2004) Turkoz, Y; Celik, O; Hascalik, S; Cigremis, Y; Hascalik, M; Mizrak, B; Yologlu, SThis experimental study was designed to determine the effects of melatonin on the levels of malondialdehyde (MDA), reduced glutathione (GSH), xanthine oxidase (XO) after adnexial torsion/detorsion (ischemia/reperfusion, I/R) of the ovaries of in rats. Forty adult albino rats were divided into five groups: sham operation, torsion, I/R plus saline, I/R plus melatonin and torsion plus melatonin. Rats in the sham-operated group underwent a surgical procedure similar to the other groups but the adnexa was not occluded. Rats in the torsion group were killed after adnexal torsion for 3 hr. Melatonin and saline were injected intraperitoneally (10 mg/kg) 30 min before detorsion to the I/R plus melatonin group and I/R plus saline group respectively. After 3 hr of ovarian detorsion, the rats were killed and ovaries were removed. Melatonin was injected intraperitoneally (10 mg/kg) 30 min before torsion to the torsion plus melatonin group. After 3 hr of ovarian torsion, the rats were killed and ovaries were harvested. The tissue levels of MDA, GSH and XO were measured. MDA and XO levels in the I/R plus saline group increased significantly when compared with torsion and sham-operated groups (P < 0.001). MDA and XO levels in the I/R plus melatonin group were lower than I/R plus saline and differences between the two groups were statistically significant (P < 0.001). GSH levels in the I/R plus saline group decreased significantly when compared with ischemia and sham-operated groups (P < 0.001). GSH levels in the I/R plus melatonin treated rats were significantly higher than I/R plus saline and ischemia groups (P < 0.001). The tissue levels of XO, MDA and GSH were similar between ischemia and ischemia plus melatonin groups. Morphologically, polymorphonuclear neutrophil infiltration and vascular dilatation were obvious in the I/R-damaged ovaries, and the changes also partially reversed by melatonin. This study demonstrates that melatonin protects the ovaries against oxidative damage associated with reperfusion following an ischemic insult.Öğe Metabolic changes in pelvic lesions: Findings at proton MR spectroscopic imaging(Karger, 2005) Hascalik, S; Celik, O; Sarac, K; Meydanli, MM; Alkan, A; Mizrak, BObjective: The purpose of this study is to investigate the in vivo magnetic resonance spectroscopic (MRS) features of pelvic lesions using long echo time and to characterize the spectral patterns of various pathological entities. Materials and Methods: 17 patients with surgically and histopathologically confirmed pelvic lesions underwent long echo-time MRS, and the results obtained were analyzed. Before laparotomy, choline (Cho), lactate, lipid and creatine (Cr) levels of all lesions were measured by single voxel MRS ( point-resolved spectroscopy technique, TE 136 ms). Voxels were placed in the center of the lesions. The MRS results of lesions were compared with the final histopathological diagnoses. Results: Spectroscopy analysis of serous, mucinous and undifferentiated carcinoma of the ovary revealed Cho, lactate and lipid signals, but granulosa-theca cell tumor showed only a lipid signal. The Cho signal was obtained from only 3 patients with mature cystic teratoma but none of the other benign ovarian tumors and pelvic abscesses. A lipid signal was detected in 3 patients diagnosed with pelvic abscess and all benign ovarian tumors. In addition to the lipid signal, a lactate signal was detected in the spectra of two pelvic abscesses. One case of endometrioma and 1 case of teratoma did not show any signal. Conclusion: MRS demonstrates significant differences in metabolite concentration between benign and malignant ovarian tumors and pelvic abscesses. MRS may therefore be helpful in the differential diagnosis of adnexal lesions. Copyright (C) 2005 S. Karger AG, Basel.Öğe The protective effect of caffeic acid phenethyl ester on ischemia-reperfusion injury in rat ovary(Elsevier Science Bv, 2004) Celik, O; Turkoz, Y; Hascalik, S; Hascalik, M; Cigremis, Y; Mizrak, B; Yologlu, SObjective: This experimental study was designed to determine the changes in tissue levels of malondialdehyde, end-product of lipid peroxidation (MDA), reduced glutathione (GSH) and xanthine oxidase (XO) and the effect of caffeic acid (3,4-dihydroxycinnamic acid) phenethyl ester (CAPE) on these metabolite levels after adnexal torsion-detorsion model in rats. Method: Forty adult female albino rats were divided into five groups: basal control (n = 8), sham operation (n = 8), torsion-detorsion plus saline (n = 8), torsion-detorsion plus CAPE (n = 8). and only torsion (n = 8). Rats in the sham operation group underwent a surgical procedure similar to the other groups but the adnexa was not torsioned. Rats in the torsion group were killed after 360degrees clockwise adnexal torsion for 3 It and ovaries were harvested. CAPE was injected intraperitoneally 30 min before detorsion in the CAPE/cletorsion group and saline was administered in the saline/detorsion group. After 3 h of adnexal detorsion, the rats in both groups were killed and adnexa were surgically removed. Results: MDA levels and XO activities in torsion-detorsion plus saline group increased significantly when compared to basal control, torsion and sham operation groups (P < 0.001). In the CAPE group, MDA levels and XO activities were lower than those of torsion-detorsion plus saline group, and differences between the two groups were statistically significant (P < 0.001). GSH levels in torsion-detorsion plus saline group were decreased significantly when compared to basal control and sham operation groups (P < 0.001). GSH levels in the CAPE group were higher than those of torsion-detorsion plus saline group, and differences between the two groups were statistically significant (P < 0.004). Morphologically, polymorphonuclear leukocytic infiltration and vascular dilatation were obvious in the ischernia-reperfusion damaged ovary, a change partially reversed by CAPE. Conclusions: These results suggest that administration of CAPE has beneficial effects in the prevention of ischemia-reperfusion injury of the ovaries. (C) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Protective effect of melatonin against oxidative stress on adhesion formation in the rat cecum and uterine horn model(Pergamon-Elsevier Science Ltd, 2005) Ara, C; Kirimlioglu, H; Karabulut, AB; Coban, S; Hascalik, S; Celik, O; Yilmaz, SThis experimental study was designed to evaluate the degree of adhesion formation and peritoneal tissue levels of malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NO) and the effect of melatonin on these metabolites in a postoperative intraperitoneal adhesion formation model in rats. Thirty adult female Wistar albino rats were subjected to standardized lesions by cecal and uterine horn abrasion and were randomly divided into three groups. Control rats were treated with 5% ethanol. Melatonin treated rats received 4 mg/kg melatonin before closure and for 10 consecutive days intraperitoneally after surgery. Rats in the sham operation group underwent a surgical procedure similar to the other groups however the peritoneal abrasion was not performed. On postoperative day 10 relaparatomy was performed. After the assessment of the adhesions, the rats in each group were sacrificed and peritoneal tissues were harvested to determine the tissue levels of MDA, GSH and NO activity. Adhesion formation scores in the melatonin group were significantly lower than that of control and sham group (p < 0.01 and p < 0.02, respectively). Tissue levels of MDA and NO were significantly lower in the melatonin treated rats when compared with control and sham groups. The levels of GSH in the melatonin treated rats were significantly higher than those of control and sham groups (p < 0.01). The results demonstrate that in this experimental model, intraperitoneal administration of melatonin decreases the extent of peritoneal adhesions and causes a decrease in MDA and NO and an increase in GSH levels. (c) 2005 Elsevier Inc. All rights reserved.Öğe Protective role of melatonin in pinealectomized rat brains: in vivo magnetic resonance spectroscopic analysis(Wiley, 2005) Hascalik, S; Celik, O; Karakas, HM; Parlakpinar, H; Firat, AK; Ozsahin, MThe goal of this study was to investigate the effect of melatonin on basic cerebral metabolites in pinealectomized (Px) rat brains. Twenty-one rats were randomly divided into three groups with seven rats per group. The study groups included sham-operated rats, Px rats and Px rats treated with melatonin. Melatonin administration began at 60 days following pinealectomy and continued for 21 days. At the end of the study, in vivo single voxel magnetic resonance spectroscopy was performed on whole brains to determine choline (Cho), creatine and N-acetyl aspartate (NAA) concentrations. Px rats had significantly lower NAA levels (P < 0.05), and significantly higher Cho levels (P < 0.05) when compared with sham-operated rats. Administration of melatonin had normalized NAA and Cho levels in Px rats. We propose that pinealectomy causes significant changes in cerebral metabolites which are compatible with neural loss. Melatonin administration prevents the disruptive effects of pinealectomy on brain tissue.Öğe Proton magnetic resonance spectroscopy findings of a sacrococcygeal schwannoma(Lippincott Williams & Wilkins, 2006) Hascalik, S; Celik, O; Erdem, G; Ara, C; Kirimlioglu, HSchwannoma is tumor of peripheral nerves, originating from Schwann cells. It is a rare nerve sheath tumor, which frequently occurs in the intracranial acoustic nerve and spinal nerves. We report on a 28-year-old woman who suffered from a large pelvic mass that was diagnosed to be sacrococcygeal schwannoma. The features of proton magnetic resonance spectroscopy (MRS) study are discussed. The magnetic resonance imaging instrument was a 1.5T, Gyroscan Intera with a body coil as a radiofrequency transmitter and a signal receiver. T2-weighted images were obtained under the following conditions-turbo spin echo (TSE) T2: turbo spin echo repeat time (TR) = 4500 msec, echo time (TE) = 96 msec. Single voxel MRS was performed by the point-resolved spectroscopy technique with a long TE (136 msec). MRS measurement was performed on two different parts of the tumor. As well as strongly elevated choline and lipid signals, the tumor spectrum showed increased N-acetylaspartate resonances. MRS can be used effectively in the preoperative diagnosis of retroperitoneal and pelvic masses, which demonstrate unusual clinical features.
