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Biomedical subjects

A Erdem

Publications and source records attributed to A Erdem.

At least 19 recordsLinked to original sources
PubMed2006

Surgery in temporal lobe epilepsy patients without cranial MRI lateralization.

High resolution MRI is very important in the evaluations of patients with intractable temporal lobe epilepsy in preoperative investigations. Morphologic abnormalities on cranial MRI usually indicate the epileptogenic focus. Intractable TLE patients who have normal cranial MRI or bilateral hippocampal atrophy may have a chance for surgery if a certain epileptogenic focus is determined. We evaluated the patients who were monitorized in Gazi University Medical Faculty Epilepsy Center from October 1997 to April 2004. Seventy three patients, who had a temporal epileptogenic focus, underwent anterior temporal lobectomy at Ankara University Medical Faculty Department of Neurosurgery. Twelve of them (16, 4%), did not have any localizing structural lesion on cranial MRI. Of the 12 patients examined 6 had normal findings and 6 had bilateral hippocampal atrophy. Of these 12 patients, 6 (50%) were women and 6 (50%) were men. The ages of patients ranged from 7 to 37 (mean: 24.5). Preoperatively long-term scalp video-EEG monitoring, cranial MRI, neuropsychological tests, and Wada test were applied in all patients. Five patients, whose investigations resulted in conflicting data, underwent invasive monitoring by the use of subdural strips. The seizure outcome of patients were classified according to Engel with postsurgical follow-up ranging from 11 to 52 (median: 35.7) months. Nine patients (75%) were classified into Engel's Class I and the other 3 patients (25%) were placed into Engel's Class II. One patient who was classified into Engel's Class II had additional psychiatric problems. The other patient had two different epileptogenic foci independent from each other in her ictal EEG. One of them localized in the right anterior temporal area, the other was in the right frontal lobe. She was classified in Engel's Class II and had no seizure originating from temporal epileptic focus, but few seizures originating from the frontal region continued after the surgery. In conclusion, surgery was successful in all 12 patients. We think that patients with no MRI lateralizing or localizing lesion should undergo epilepsy surgery after detailed presurgical evaluations, including invasive monitoring.

Adolescent↗
PubMed2004

Endothelin 1 and leptin in the pathophysiology of intrauterine growth restriction.

OBJECTIVES: To evaluate the relationship of endothelin 1 (ET-1) and leptin concentrations in women and newborns following a pregnancy complicated with intrauterine growth restriction (IUGR). METHODS: Twenty-five women with a pregnancy complicated with IUGR at 19 different gestational ages were matched with women with uncomplicated pregnancies. Blood samples from the umbilical artery and maternal peripheral venous circulation were collected at delivery, and ET-1 and leptin levels were determined from the blood samples. Data relating to obstetric complications (e.g., pregnancy-induced hypertension), delivery (e.g. mode, birth weight, signs of intrapartum fetal distress, and Apgar scores) were also recorded. RESULTS: Mean maternal ET-1 (13.4+/-6.2-9.9+/-2.9 pmol/l) and mean fetal ET-1 (14.5+/-4.2-11.7+/-3.1 pmol/l) concentrations were significantly higher when women had experienced pregnancies complicated with IUGR than when they had had normal pregnancies. Mean fetal leptin concentration was significantly lower in the study group (6.8+/-2.2 ng/ml) than in the control group (10.6+/-3.6 ng/ml (P<0.05). However, fetal leptin per kilogram of fetal weight was not significantly different in the study group (3.16+/-1.18 ng/ml) than in the control group (3.23+/-0.96 ng/ml) (P>0.05, paired t-test). However, a statistically significant correlation was observed between fetal leptin concentrations per kilogram of fetal weight and fetal endothelin concentrations in pregnancies complicated with IUGR (r=0.546; P<0.05). CONCLUSIONS: These results suggest the intertwined roles of ET-1 and leptin in the pathophysiology of IUGR. Further studies concerning interaction between these peptides in different pregnancy conditions may provide important information about the actions of ET-1 and leptin on fetal growth.

Adult↗
PubMed2004

Infratemporal and intraorbital metastasis of the glioblastoma multiforme. A case report.

Primary brain tumors rarely metastasize outside of the central nervous system. A case of 37-year-old woman with a temporal lobe glial tumor which shows infratemporal and orbital invasion is presented. She had undergone a cranial operation because of temporal lobe epilepsy 8 years ago. Defects on the dura and bone flap were thought to be the mechanisms of the infratemporal fossa invasion. The case illustrates extra-axial metastasis of glioblastoma multiforme, an exceptional finding.

Astrocytes↗
PubMed2003

Infection-related atlantoaxial subluxation in two adults: Grisel syndrome or not?

Grisel's syndrome involves the subluxation of the atlanto-axial joint from inflammatory ligamantous laxity following an infectious process in the head or neck. It is a rare disease usually affecting children, but infrequent adult cases do occur. Today, due to the widened use of antibiotics and availability of MR imaging, some cases presenting with neck pain, resulting from the infectious inflammation of C1 and C2 but without pronounced subluxation, can be a challenging problem for most neurosurgeons. Several theories have been proposed to explain the pathogenesis of inflammatory subluxation. The primary treatment of Grisel's syndrome is medical. The underlying infectious organism must be isolated and appropriate antibiotics must be prescribed. The subluxation is reduced in holter or skeletal traction. This paper reports two cases of infection-related atlanto-axial subluxation in two adults. The literature on this subject is briefly reviewed.

Adult↗
PubMed2003

Transvaginal color Doppler ultrasonography for prediction of pre-cancerous endometrial lesions.

OBJECTIVE: To determine whether measurements of blood flow in endometrial and uterine vessels by transvaginal color Doppler ultrasonography was valuable in the diagnosis of a neoplastic endometrial pathology (hyperplasia and carcinoma) in women with abnormal bleeding. METHODS: This is a prospective study and included 105 post-menopausal women and 33 pre-menopausal women with abnormal uterine bleeding. All subjects underwent transvaginal color Doppler ultrasonography. We investigated whether obtained results were correlated with histopathological findings. RESULTS: There was no significant difference in the mean+/-S.D. RI of the left and the right uterine arteries, intramyometrial arteries and endometrial arteries between patients with neoplastic and non-neoplastic endometrium on histopathological examination. Doppler's velocity waveforms of small endometrial blood vessels could be detected in 9% of the women with non-neoplastic endometrium and in 42% of the women with neoplastic endometrium (P<0.05). The mean+/-S.D. of the endometrial thickness was significantly higher in the women with neoplastic endometrium than that of the women with non-neoplastic endometrium (16.6+/-6.1 mm vs. 9.5+/-4.7 mm, P<0.05). CONCLUSION: Doppler's velocity waveforms of uterine vessels coupled with transvaginal ultrasonography are not valuable enough to replace histopathological examination in the diagnosis of a neoplastic endometrial pathology. However, it may be helpful in cases in which invasive techniques are difficult to perform and in the differentiation of a certain group of patients at little risk of endometrial carcinoma.

Aged↗
PubMed2003

Age-related changes in ovarian volume, antral follicle counts and basal follicle stimulating hormone levels: comparison between fertile and infertile women.

Our objective was to compare the relationship between age, basal follicle stimulating hormone (FSH) level and ultrasound-measured mean ovarian volume (MOV) and mean antral follicle counts (MFC) in a group of infertile and fertile women between the ages of 35 and 45 years. Menstrual cycle day 3 serum FSH, MOV and MFC were analyzed in 62 infertile and 53 fertile women. Basal FSH and MFC did not differ between infertile and fertile women, whereas MOV was significantly smaller in infertile women (p < 0.05). In the infertile group, there was a negative correlation between MOV and age (rho = -0.389, p < 0.05), between MOV and basal FSH (rho = 0.495, p < 0.01), and between MFC and age (rho = -0.553, p < 0.01). In the fertile group, there was a strong negative correlation between MOV and basal FSH (rho = -0.631, p < 0.01), and between MFC and basal FSH (rho = -0.710, p < 0.01). Mean basal FSH, MOV and MFC did not differ between subgroups of patients with different causes of infertility. In the infertile group, patients with small ovaries of volume less than 1.8 cm(3) (mean volume -1 SD) had higher mean basal FSH (p < 0.05) and lower MFC (p < 0.01) levels than patients with normal ovarian volume. In conclusion, transvaginal ultrasound (TVU) indices and indirect hormonal parameters of ovarian reserve were similar in infertile and fertile women aged between 35 and 45 years. It is suggested that, in infertile women above 35 years of age, TVU rather than hormonal parameters be preferred, based on our data showing a stronger association between age and TVU indices of ovarian reserve than between age and increase in basal FSH level. Thus, TVU assessment of ovarian volume and antral follicle counts is a practical and cost-effective, if not better, technique for ovarian reserve testing.

Adult↗
PubMed2002

The effect of maternal anemia and iron deficiency on fetal erythropoiesis: comparison between serum erythropoietin, hemoglobin and ferritin levels in mothers and newborns.

OBJECTIVE: Maternal and fetal serum erythropoietin levels were correlated with hemoglobin, mean corpuscular volume and serum ferritin in a group of anemic pregnant women to evaluate the effect of maternal anemia on fetal erythropoiesis. METHODS: Serum erythropoietin, ferritin, hemoglobin and mean corpuscular volume were investigated in 33 pregnant women with anemia, 11 women with normal hematological parameters and in their newborns. RESULTS: Maternal serum erythropoietin concentration (mean +/- SEM) was significantly higher in the anemic group (145.2 +/- 42.9 mU/ml) as compared to the control group (37.3 +/- 7.6 mU/ml) (p < 0.05). In newborns, all parameters were comparable in both groups except cord serum erythropoietin concentration (mean +/- SEM) which was significantly higher in newborns born to anemic women (43.9 +/- 5.3 mU/ml) than controls (29.4 +/- 3.7 mU/ml) (p < 0.05). In the anemic group, maternal serum erythropoietin was inversely correlated to maternal hemoglobin (r = -0.375, p = 0.03), maternal hemoglobin was inversely correlated to cord serum erythropoietin (r = -0.552, p = 0.001) and maternal ferritin was correlated to fetal ferritin (r = 0.521, p = 0.002). CONCLUSION: Although cord hemoglobin and mean corpuscular volume were not affected by maternal anemia, increased cord serum erythropoietin levels related to low maternal hemoglobin levels suggest an induced fetal erythropoiesis in maternal anemia.

Anemia, Iron-Deficiency↗
PubMed2002

Incidental tubo-ovarian abscess at abdominal delivery: a case report.

Tubo-ovarian abscess in the third trimester of pregnancy is extremely rare. In this report, an unusual case with asymptomatic tubo-ovarian abscess, diagnosed incidentally during Cesarean section performed for an obstetric indication, is presented. Unlike other reported cases, no signs or symptoms attributable to pelvic abscess throughout the pregnancy were observed in our patient. To our knowledge, this is the first report of such a case in the literature.

Abscess↗
PubMed2001

Magnetic bead-based label-free electrochemical detection of DNA hybridization.

Magnetic bead capture has been used for eliminating non-specific adsorption effects hampering label-free detection of DNA hybridization based on stripping potentiometric measurements of the target guanine at graphite electrodes. In particular, the efficient magnetic separation has been extremely useful for discriminating against unwanted constituents, including a large excess of co-existing mismatched and non-complementary oligomers, chromosomal DNA, RNA and proteins. The new protocol involves the attachment of biotinylated oligonucleotide probes onto streptavidin-coated magnetic beads, followed by the hybridization event, dissociation of the DNA hybrid from the beads, and potentiometric stripping measurements at a renewable graphite pencil electrode. Such coupling of magnetic hybridization surfaces with renewable graphite electrode transducers and label-free electrical detection results in a greatly simplified protocol and offers great promise for centralized and decentralized genetic testing. A new magnetic carbon-paste transducer, combining the solution-phase magnetic separation with an instantaneous magnetic collection of the bead-captured hybrid, is also described. The characterization, optimization and advantages of the genomagnetic label-free electrical protocol are illustrated below for assays of DNA sequences related to the breast-cancer BRCA1 gene.

BRCA1 Protein↗
PubMed2001

Contraceptive practices of women after abortion in Turkey.

OBJECTIVES: The aim ofthis study was to determine the postabortion contraception choices of women and the subsequent reduction in pregnancy rate. The changes in method of contraception during the 1-year follow-up period were also assessed. METHODS: Ninety women decided to practice family planning methods following an abortion procedure. The family planning choices of the postabortion family planning group were determined by active immediate family planning counselling. The control group, which consisted of 23 women who had had an abortion and wanted to become pregnant again, were followed-up for 1 year to determine their pregnancy rate. The pregnancy rates and methods used were determined during a 12-month follow-up period. RESULTS: Following counselling, 79.64% of the patients signed for immediate family planning practice. In the postabortion family planning group, one out of 90 patients (1.1%, Pearl index 1.29) practising contraception with a condom became pregnant. However, ten out of 23 (43.5%, Pearl index 54.2) patients in the control group became pregnant during the 1-year follow-up period (p < 0.05). In the postabortion family planning group, intrauterine devices (IUDs) (n = 43), injectable monthly contraceptives (n = 24) and tubal ligation (n = 9) were the most commonly preferred methods, with 47%, 27% and 10% of the women using these methods, respectively. At the end of the 12-month period, the drop-out rate among women using the injectable monthly contraceptives was significantly higher (13 patients, 54%) compared to other methods (p < 0.05). In one case out of 43 using an IUD (2.38%), the IUD was expelled during follow-up. CONCLUSION: The use of postabortion family planning significantly decreased the postabortion pregnancy rate. The use of an IUD was the preferred immediate method of choice. Use of injectable monthly contraceptives was the method with the highest drop-out rate. The expulsion rate of postabortion IUDs was acceptable in our practice. The pregnancy rate in the control group was lower than the physiological fecundity would predict. This may suggest that, although couples plan to get pregnant, they do not concentrate on the ideal conditions for conception or they do, in fact, practice some form of family planning.

Abortion, Induced↗
PubMed2000

The protective effect of taurine against gentamicin-induced acute tubular necrosis in rats.

BACKGROUND: Taurine, which is the major intracellular free beta-amino acid, is known to be an endogenous antioxidant and a membrane-stabilizing agent. In this study, we wished to know whether taurine altered the concentration of gentamicin in kidney tissue and could protect against gentamicin-induced acute proximal tubular injury. METHODS: Wistar albino rats of both sexes were assigned to three groups, which all received one of the following daily intraperitoneal injections for 8 days: (i) 0.9% sodium chloride (NaCl) alone at the same volume as gentamicin treated rats (group C; n=8); (ii) 100 mg/kg/day gentamicin alone (group G; n=8, four male, four female); or (iii) 100 mg/kg/day gentamicin plus 7.5 ml/kg/day taurine (group G+T; n=9, five male, four female). Urine was collected for 24 h for the determination of urine volume and creatinine. Intracardiac blood was collected for blood urea nitrogen (BUN) and serum creatinine determination. The kidneys were removed, weighed, and the left kidneys were subjected to biochemical analysis for the determination of thiobarbituric acid-reactive substance (TBARS) and lactate levels, and glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities. The right kidneys were divided vertically in half. The upper halves were used for histopathological examination, by light and electron microscopy. The lower halves were used to detect the gentamicin concentration within the kidney tissue, by high-performance liquid chromatography (HPLC). Changes in body weight and normalized kidney weight were recorded. RESULTS: Taurine treatment reduced gentamicin-induced increases in serum creatinine, 24 h urine volume, BUN and tissue lactate and TBARS levels (0.57+/-0.02 vs 1.06+/-0.08 mg/dl, P<0.001; 9.00+/-1.46 vs 20.9+/-2.73 ml, P<0.001; 25.3+/-1.87 vs 54.1+/-6.99 mg/dl, P<0. 001; 2.56+/-0.10 vs 3.44+/-0.08 micromol/g wet tissue, P<0.001; and 66.4+/-3.41 vs 79.5+/-5.07 nmol/g wet tissue, P>0.05, respectively). Taurine reduced the accumulation of gentamicin within the kidney tissue (233+/-29 vs 494+/-93 microg/g wet tissue, P<0.05). Taurine treatment also prevented body weight loss due to gentamicin administration (17.8+/-1.64 vs -10.0+/-7.08 g, P<0.01) and normalized reduced Gpx and SOD activities (3.46+/-0.16 vs 2.37+/-0. 15 U/g wet tissue, P<0.01; and 15577+/-377 vs 12662+/-577 U/g wet tissue, P<0.01, respectively). Light microscopic examination of the renal tissues from gentamicin-treated rats revealed severe histopathological changes, whereas specimens obtained from taurine-treated rats revealed only mild changes. This finding was supported by electron microscopic examination. CONCLUSIONS: Our observations suggest that taurine treatment attenuates the accumulation of gentamicin within kidney tissue and counteracts the deleterious effect of gentamicin on renal tubular function. They may have potentially important clinical implications.

Acute Disease↗
PubMed2000

Fatal toxic effect of bleomycin on brain tissue after intracystic chemotherapy for a craniopharyngioma: case report.

OBJECTIVE AND IMPORTANCE: Craniopharyngiomas are benign neoplasms of epithelial origin that arise from the remnants of Rathke's pouch and are located in the sellar, parasellar, and third ventricular regions. Despite major advances in microsurgical techniques, total removal of these tumors is associated with a high risk of death, long-term endocrinological dependence, cognitive dysfunction, and behavioral disorders. For patients with monocystic craniopharyngiomas, encouraging postoperative survival rates and high rates of cyst regression after intracavitary administration of bleomycin have been reported. Moreover, only a few side effects have been reported for this treatment method. We report a patient with a cystic craniopharyngioma who was treated using intracavitary bleomycin administration and died as a result of the direct toxic effects of bleomycin on deep brain structures and the brainstem. CLINICAL PRESENTATION AND INTERVENTION: A 47-year-old woman with a cystic craniopharyngioma underwent stereotactic insertion of a catheter attached to a subcutaneous reservoir. Five months after the procedure, positive-contrast computed tomographic cystography was performed to confirm the absence of fluid leakage. Daily intracavitary injections of bleomycin were administered through the reservoir into the cyst, until a total dose of 56 mg had been administered in 8 days. After the treatment, the cystic cavity regressed but the patient exhibited neurological deterioration; magnetic resonance imaging scans revealed diffuse edema in the diencephalon and brainstem. The patient died 45 days after completion of the treatment. CONCLUSION: Intracavitary administration of bleomycin is not a treatment protocol without risks or side effects, even if there is no fluid leakage into the cerebrospinal fluid. Although this is known to be an effective treatment for cystic craniopharyngiomas, previous reports cannot be used to establish a standard treatment method, and more research is needed to yield a safer effective protocol.

Antimetabolites, Antineoplastic↗
PubMed1998

Multielectrode array for simultaneous recording of glucose, oxygen and electrocorticography from cerebral cortex in experimental focal epilepsy.

Delineating epileptic tissue before and during surgery is still a major problem. Electroencephalography (EEG), electrocorticography (ECoG), and magnetoencephalography (MEG) evaluations may not always correlate with outcome. Metabolic mapping, i.e. positron emission tomography (PET) or single photon emission tomography (SPECT), is not practical or not sensitive--both spatial and temporal--enough for use in neurosurgery. Amperometric electrochemical electrodes for recording oxygen and glucose from nervous tissue are developed and tested in rat experimental focal penicillin epilepsy model. With a three-by-three array of glucose electrodes, epileptic focus is mapped. Simultaneous recordings of ECoG, oxygen and glucose levels performed. During seizure, extracellular glucose level showed a biphasic response pattern while oxygen level decreased slightly. It has been concluded that such a combined subdural grid recording might help before and during surgery. This method can be used in ischemia and such experimental metabolic studies.

Animals↗
PubMed1997

The effect of antioxidant vitamins E and C on lipoperoxidation of erythrocyte membranes during hyperbaric oxygenation.

The aim of this research was to determine whether administration of an antioxidant vitamin combination can reduce oxidative damage in erythrocytes induced by hyperbaric oxygenation (HBO). Malonyldialdehyde (MDA) levels and osmotic fragility ratios in erythrocytes of 28 rats were compared in group A [control], group B [Vitamin (E + C)], group C [HBO] and group D [HBO + Vitamin (E + C)]. HBO was applied at a pressure of 2.8 atmospheres absolute (ATA), 1 hour daily, for 45 days in groups C and D. Administration of alpha-tocopherol acetate (40 mg/kg) and Na-ascorbate (200 mg/kg) was initiated 3 days before the start of HBO exposures and administered intraperitoneally 3 times a week for 45 days. MDA levels and osmotic fragility ratios were significantly higher in group C than in groups A and B (p < 0.05 for all). Significant decreases in MDA levels and osmotic fragility were observed in group D compared with group C, although these parameters were still significantly higher than in controls (p < 0.05 for all). Prolonged HBO resulted in oxidative damage indicated by significant increases in MDA levels and osmotic fragility ratios, which were reduced by concomitant vitamin (E + C) administration.

Animals↗
PubMed1996

Osteochondroma of the upper cervical spine. A case report.

STUDY DESIGN: A report of a patient with osteochondroma of the upper cervical spine causing radiculopathy. OBJECTIVES: The surgical treatment of this patient involved the complete removal of tumor and compression of neural structures. SUMMARY OF BACKGROUND DATA: Osteochondromas affect mostly the long bones. Involvement of spine by solitary osteochondromas is rare condition. The present report represents a case of spinal osteochondroma causing neurologic symptoms. METHODS: Cervical osteochondromas, best evaluated with routine magnetic resonance imaging and noncontrast computed tomography scans, rarely contribute to cervical nerve root compression. RESULTS: The patient's symptoms gradually resolved after gross total tumor removal. CONCLUSIONS: Symptomatic spinal osteochondromas are rare occurrences in an individual surgeon's experience. Computed tomography or magnetic resonance imaging are the imaging procedures of choice. In the majority of patients with myelopathy or radiculopathy, surgery results in complete relief of symptoms as demonstrated in this case.

Adult↗