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Biomedical subjects

A Erbengi

Publications and source records attributed to A Erbengi.

At least 19 recordsLinked to original sources
PubMed1998

Aneurysms of the distal anterior cerebral artery: report of 14 cases and a review of the literature.

BACKGROUND: Distal anterior cerebral artery aneurysms are rare and compose about 4.5% of all intracranial aneurysms. They generally arise at the bifurcation of the pericallosal and callosomarginal arteries. Their surgical approach is different from those of other anterior circulation aneurysms. These aneurysms present some special difficulties for neurosurgeons, including narrow exposure in the interhemispheric fissure, dense adhesions between the cingulate gyri, difficulty in controlling the parent artery, and the association of multiple aneurysms and vascular anomalies. METHODS: Between January 1975 and May 1996, 14 cases of saccular aneurysms of the distal anterior cerebral artery were operated at the University of Hacettepe. The clinical presentations, neuroradiological findings, and operative approaches of these aneurysms were analyzed. In addition, the clinical series and isolated case reports in the English literature were also extensively reviewed. RESULTS: The incidence of the aneurysms in this location was 2.8% of a total of 494 surgically treated cases in our center. Of 14 patients, eight were women and six were men. Multiple aneurysms were found in five patients (35%). All patients were operated via the interhemispheric route. Thirteen patients had good outcome and one patient died. CONCLUSIONS: We believe that all difficulties related to distal anterior cerebral artery aneurysms can be minimized with sufficient knowledge of microsurgery and surgical anatomy, using microtechniques and experience.

Adult↗
PubMed1998

Cerebral aneurysm surgery in a patient with phaeochromocytoma.

This case report describes the peri-operative management of a 48-year-old woman with three cerebral aneurysms and phaeochromocytoma. The pharmacological and anaesthetic management of such patients is complex, and needs to be managed carefully by titrating anaesthetic agents and vasoactive drugs. The primary concern is the maintenance of cerebral perfusion pressure and autoregulation throughout the procedure, although these states cannot be monitored directly. The patient survived the operation neurologically intact, and it is presumed that the course of management which was chosen helped to achieve this result.

Adrenal Gland Neoplasms↗
PubMed1998

Neurotransmitter and amino acid analysis and ultrastructural observations of fetal brain cortex transplantation to adult rat brain under the effect of dexamethasone.

OBJECTIVE: To conduct an investigation of fetal cortical tissue graft survival using transmission electron microscopy and analyzing neurotransmitters and amino acids and their function, with special reference to the effect of dexamethasone. METHODS: Transplantation of fetal cortical brain tissue to 100 adult Wistar albino rats weighing 170 to 220 g was performed. The rats were divided into three groups. Only transplantation of fetal cortical brain tissue was performed in the first group (n=36). In the second group (n=48), dexamethasone was administered in addition to fetal cortical tissue transplantation. The third group (n=16) was used as the surgical control group. The rats were allowed to live for 6 weeks and were then decapitated. The grafts were examined by electron microscopy. Additionally, quantitative analyses of the neurotransmitters and amino acids of the grafts were conducted using high-pressure liquid chromatography. RESULTS: Electron microscopic observations revealed that the grafts were still surviving at the end of the 6th week in both groups. However, in the group that received dexamethasone, neurons and their organelles were better developed than in the group that did not receive dexamethasone. Concommitantly, results of quantitative analysis in the dexamethasone group revealed statistically extremely significant higher amino acid values for glutamic acid, aspartic acid, beta-alanine, and lysine and significantly higher values for gamma-aminobutyric acid, glutamine, glycine, and serine when compared to the nondexamethasone group. CONCLUSION: Dexamethasone is effective in increasing the survival and in developing the ultrastructural and functional outcome of transplanted neurons in fetal grafts.

Amino Acids↗
PubMed1997

Pheochromocytoma and multiple intracranial aneurysms: is it a coincidence? Case report.

The authors present a case of multiple intracranial aneurysms associated with a pheochromocytoma. The aneurysms were successfully clipped, and a suprarenal tumor located on the left side was totally removed. To the authors' knowledge this is the fourth reported case of these combined entities in the literature. The authors speculate on the possible etiopathogenesis of the relationship between intracranial aneurysms and attacks of hypertension caused by the presence of neoplasms that discharge acute and irregular levels of catecholamines, especially pheochromocytomas. Perioperative management designed to avoid undesired complications in this rare association is also discussed.

Adrenal Gland Neoplasms↗
PubMed1996

Effect of Nd:YAG laser on experimental disc degeneration. Part I. Biochemical and radiographical analysis.

Intervertebral disc herniation is an important health problem from both the social and economic aspect. It is often accompanied by a decrease in the content of water and proteoglycan (PG). The present study was undertaken to elucidate the effect of neodymium-yttrium-aluminum-garnet (Nd:YAG) laser on degenerated disc tissue. In this study a ventral disc herniation model in guinea pigs was performed to study the effects of ND:YAG laser on degenerated disc with low water and PG content. Effect of ND:YAG laser on degenerated cervical disc tissue is examined from the aspects of biochemistry and radiology. In the acute period water, PG, and collagen content decreased due to the ablative effect of ND:YAG laser on disc tissue. When changes in the degenerated disc in the post-laser chronic period were compared with degenerated disc findings, statistically significant changes could not be be found. From the results of this study, there is no question that the Nd:YAG laser offers many potential benefits, it remains to be proven whether or not this is of real benefit in the treatment of patients with degenerated disc disease.

Analysis of Variance↗
PubMed1996

The effect of pinealectomy and foetal pineal transplantation of collagen ageing in rats.

Recent progress in pineal research emphasized the importance of this circumventricular organ in the phenomenon of ageing as well. The present study was undertaken to elucidate the effects of pineal gland on collagen ageing by spectrofluorometrically measuring collagen-cross-link bound fluorescein. Experiments were performed on three different age groups of rats (3-4 weeks, 8-10 weeks, 15 and more weeks). Fluorescein values were found to increase causally by age in the control group. Eight weeks after sham operation of all the groups fluorescein level increments were shown to be parallel with the values of normal physiological ageing values. In experimental groups; in 3-5 weeks old rats pinealectomy produced a significant premature collagen ageing and this was found to be completely reversed by foetal pineal gland transplantation, but the reversal was limited to a sham operation level. On the other hand although a premature collagen ageing was found to be induced 8 weeks after pinealectomy in 8-10 weeks old rats with a statistical significance both within subject values and between sham operation and pinealectomy, foetal pineal gland transplantation was found not to reverse the premature ageing induced by pinealectomy. In 15 weeks old and older groups of rats, pinealectomy was found to facilitate the intrinsic ageing phenomenon of collagen with statistical significance again both within subject values and between sham operation and pinealectomy. Foetal pineal gland transplantation was not performed in this age group of rats. On interpretation of the data of pinealectomy against sham operation for all the age groups, the maximum degree of percentage increase in collagen-cross-link bound fluorescein was found in 3-5 weeks old rats (%218). The percentage increase in fluorescein values was found to be %170 and %126 in 8-10 weeks old and 15 weeks old and older rat groups, respectively. Consequently, we have experimentally shown the induction of collagen ageing by pinealectomy and the restorative competence of foetal pineal gland transplantation in the present study. The results seem to be impressive and details of the ageing process are the subject of further research.

Aging↗
PubMed1996

Subependymal giant cell astrocytoma associated with tuberous sclerosis: diagnostic and surgical characteristics of five cases with unusual features.

Five children with tuberous sclerosis and intracranial tumors were surgically treated at Neurosurgery Department of Hacettepe University School of Medicine. Two of the five patients presented with the giant cell astrocytoma filling the third ventricle. Direct surgical intervention and tumor removal was carried out in all four patients (three with a total surgical resection and one with a subtotal resection) and cerebrospinal fluid shunting procedure in one. Histopathological examination revealed giant cell astrocytomas in four patients. Postoperatively, one died and the rest four patients survived with minor focal neurologic difficulties. The surgical results and the changing concepts in the treatment of tuberous sclerosis are discussed and the literature is reviewed.

Adolescent↗
PubMed1996

Twenty-five years experience in the treatment of trigeminal neuralgia. Comparison of three different operative procedures in forty-nine patients.

A series of 49 patients with trigeminal neuralgia (TN) were treated by three different surgical procedures: (1) peripheral ablative procedures in 10 patients; (2) percutaneous rhizotomy in 17 patients and (3) intracranial rhizotomy (IR) in 22 patients. On the basis of surgical treatment, the concept that neurovascular compression is a mechanical factor in the aetiology of TN was supported in 14 to 18 patients who underwent posterior fossa exploration. The results support the conclusion that retromastoid craniectomy with IR is the procedure of choice for the majority of patients with TN.

Adult↗
PubMed1996

Low cervical chordoma: case report.

We report a case of a 32-year old woman with radicular symptoms associated with a low cervical chordoma. According to our knowledge this is the 10th case of low cervical chordoma reported in the literature.

Adult↗
PubMed1996

Factors affecting morbidity and mortality following surgical intervention in patients with intracranial meningioma.

BACKGROUND: Meningiomas usually grow slowly but they may cause recurrences despite surgical resection. The impact of clinical, neuroradiological and surgical characteristics on operative morbidity and mortality of patients operated on for intracranial meningioma was analysed. METHODS: A series of 450 patients operated on for intracranial meningiomas at the Department of Neurosurgery, Hacettepe University Hospital during the period 1964-1992 is reported. The surgical results were analysed with regard to intracranial site, extent of removal, histological type, and different time periods. Computed tomography (CT) and magnetic resonance imaging (MRI) facilitated the diagnosis and helped with the planning of treatment. RESULTS: Two hundred and ninety-two patients were examined with both CT and MRI. Overall mortality was 4% but showed a decline from 9% in the pre-CT era to 3% in the post-CT era and to 1% in the past 3 years. CONCLUSIONS: Operative mortality and recurrence rates are affected by the intracranial location of the tumour, histological type, and extent of tumour removal. Emphasis is also given to the importance of the introduction of the imaging techniques, and the microsurgical techniques with the Cavitron ultrasonic surgical aspirator (CUSA), laser, and/or bipolar coagulator which have further improved the operative mortality and recurrence rates.

Adolescent↗
PubMed1996

Spontaneous cerebellar strokes. Clinical observations in 60 patients.

This is a retrospective study carried out by clinical analysis of the authors' experience in 60 patients with cerebellar strokes--of which 39 were spontaneous cerebellar hemorrhage and 21 were cerebellar infarction--to compare the clinical presentation, course, and prognosis. Hypertension was found to be the most important etiologic factor. Clinical differentiation of cerebellar hemorrhage from infarction was not possible, but the management was similar in both entities. Computerized tomography was necessary to make diagnosis of the stroke mechanism. In evaluating outcome, the authors conclude that the most important single factor affecting the prognosis was the early correct diagnosis.

Adolescent↗
PubMed1996

Central nervous system involvement in gestational trophoblastic neoplasia.

BACKGROUND: To review the experience of seven cases of gestational trophoblastic neoplasia with central nervous system involvement. METHODS: Seven patients among 50 cases of malignant gestational trophoblastic neoplasia were analyzed retrospectively in a single institution. RESULTS: The mean age of the patients at diagnosis was 28.7 years (range: 20-34). While five of the patients presented initially with symptoms related to cranial involvement, the remaining two developed cerebral metastases during the therapy. In two patients, the presentation was so similar to a primary cranial pathology that craniotomy and biopsy revealed the trophoblastic involvement. The sites of involvement were the parietal lobe in three, temporal lobe in two and frontal lobe in two patients. Besides central nervous system involvement, four had additional lung and one had pelvic metastases. In terms of therapy, while five patients received methotrexate+actinomycin-D+cyclophosphamide regimen for 3 to 5 courses, only two could be administered additional intrathecal methotrexate. Since one patient exhibited a fulminant clinical course, she could not be delivered a chemotherapy regimen and was lost in two months of initial diagnosis. The other patient was administered modified Bagshawe protocol (5 courses) which was switched to etoposide+methotrexate+actinomycin-D+vincristine+cyclophosphamide (6 courses) due to development of resistance. She was still alive and free of disease after 24 months of initial diagnosis. Six of the patients were also delivered whole-brain irradiation simultaneously with chemotherapy. CONCLUSIONS: The prognosis of brain metastases still seems to be poor despite combination chemotherapy and radiotherapy. Measures should be focused on early diagnosis and prophylaxis.

Adult↗
PubMed1995

Pulmonary embolism in neurosurgical patients.

BACKGROUND: Pulmonary embolism continues to be a frequent cause of morbidity and mortality in neurosurgical practice. This study was designed to investigate the presence of signs and/or symptoms helpful for an early diagnosis of pulmonary embolism and to evaluate the safety of heparin treatment in neurosurgical patients. METHOD: We retrospectively reviewed 37 patients with pulmonary embolism among 6081 operated patients within the past 8 years at the Department of Neurosurgery, University of Hacettepe. RESULTS: The overall incidence of pulmonary embolism was 0.42% and the mortality rate was 59.4%. The patients with cerebrovascular lesions had a significantly higher risk of pulmonary embolism compared with other neurosurgical pathologies. All patients were treated with heparin and subsequent oral warfarin therapy. None had intracranial or intraspinal bleeding while receiving anticoagulant therapy. CONCLUSIONS: This study demonstrates that pulmonary embolism has a high mortality rate and heparin therapy can be used safely and without fear of intracranial or intraspinal bleeding.

Adolescent↗
PubMed1995

Congenital nasal encephalocele: a review of 35 cases.

Congenital encephaloceles are rare lesions which are usually seen in the occipital region, in the West. They may rarely be seen in the frontal region and they have distinct diagnostic features, together with several other pathological conditions occurring in this region. In order to emphasize these points, a retrospective analysis of 35 cases which have been operated on in our clinic, is made in this study. The findings are compared with the data obtained from the literature.

Bone Transplantation↗
PubMed1994

Morphological assessment in pinealectomy and foetal pineal gland transplantation in rats: Part I.

The effects of pineal gland, an endocrine organ known to affect the physiology of various organs and systems including the hypothalamo-hypophyseal axis, on the morphological characteristics of target organs were investigated in rats after pinealectomy and foetal pineal gland transplantation to a subpial cortical area close to the pinealectomized region. It was demonstrated that weight gain was significantly slower in pinealectomized male rats (p < 0.01); pituitary gland weight was lower in the pinealectomized group (p < 0.01) and transplantation had no effect on the weight of this organ; weight of adrenal gland and testis were lower after pinealectomy (p < 0.01) but restored back to control levels after transplantation; the mitotic activity in seminiferous tubules increased with pinealectomy and returned back to control indexes after transplantation. Research on hypothalamic catecholaminergic content revealed a diminished histofluorescence in pinealectomized rats which showed a potentiated restoration after transplantation. The innervation of the pineal gland was studied by anterograde and retrograde injections of Wheat Germ Agglutinin Horse Radish Peroxidase from superior cervical ganglion and pineal gland, respectively. It was demonstrated that cell bodies were traced both at the transplanted tissue and hypothalamus. In view of these data, the multifunctional and a probable high level homeostatic harmony regulator essence of pineal gland is discussed.

Adrenal Glands↗
PubMed1994

Behavioural assessment of pinealectomy and foetal pineal gland transplantation in rats: Part II.

Pineal gland is an endocrine organ which exerts regulatory effects on the activity of various organs and systems. The present study was undertaken to highlight in experimental animals the possible integrative function of this endocrine organ on a behavioural pattern. Pinealectomy and foetal pineal gland transplantation to a subpial cortical area close to the pinealectomized region was performed. Behaviour was defined through motor activity induced by low (2 mg/kg) and high (10 mg/kg) doses of amphetamine in rats. It was shown that pinealectomy produced significant different patterns of behaviour induced by low and high doses of amphetamine. In sham operated animals low dose amphetamine induced a significant locomotor stimulation but without stereotyped activity. High dose amphetamine induced stereotyped activity. After pinealectomy even low dose amphetamine produced the behavioural pattern of stereotyped activity resembling a high dose amphetamine-induced behaviour. This differential effect of amphetamine, seen in pinealectomized rats, was completely restored after transplantation. On the other hand, melatonin treatment did not generate a significant alteration of behavioural profile either in the control or pinealectomized group of rats. Results are discussed with regard to the general regulatory function of the pineal gland.

Amphetamine↗
PubMed1994

Preventive effect of intracisternal heparin for proliferative angiopathy after experimental subarachnoid haemorrhage in rats.

Proliferative angiopathy represents the morphological basis of delayed cerebral vasospasm. The initial vasoconstriction and endothelial damage of the vasospastic arteries leads to an exaggerated response of the smooth muscle cells within the media leading to subintimal thickening and myonecrosis. Heparin reduces the exposure of the media to platelet derived growth factor, a mitogen from aggregating platelets responsible for the migration and proliferation of the myofibroblasts. Since systemic heparin in the setting of a subarachnoid haemorrhage would be unacceptable, we have tested the effect of heparin on proliferative angiopathy by injecting autologous non-heparinized blood into two groups of rats (N = 12 each) and then inject the heparin into the spinal fluid of one group after one hour. We were able to show histologically that intracisternal heparin injection after the subarachnoid haemorrhage has reduced the vascular wall changes to a great degree. Heparinization of the cerebrospinal fluid carried out in conjunction with early operation for aneurysms may be a promising approach to prevent the morbid complications of SAH in the clinical setting.

Animals↗