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Biomedical subjects

O E Ozcan

Publications and source records attributed to O E Ozcan.

At least 19 recordsLinked to original sources
PubMed1998

Importance of cranial nerve involvement in nasopharyngeal carcinoma. A clinical study comprising 124 cases with special reference to clinical presentation and prognosis.

A review of nasopharyngeal carcinomas (NPCs) treated in the Hacettepe University Hospitals is presented. One hundred twenty-four patients between the ages of 3 years and 72 years were managed in the period 1968-1992. Of these cases, 48 had only cranial nerve (CN) involvement on admission. The most commonly affected CNs were the VIth and the Vth, in that order. The prognostic significance of this finding is obvious, because early diagnosis and treatment is vital in a cancer patient. This study includes retrospective analysis of 124 patients with NPC. The patients were investigated with respect to clinical and radiological diagnosis and outcome. Our results also show that CN involvement in NPC usually requires careful neuro-otological examination. It is suggested that increased knowledge and understanding of the disease among neurosurgeons, neurologists and ENT surgeons would improve the prognosis of patients with NPC.

Adolescent↗
PubMed1998

The neurosurgical aspects of neurofibromatosis 2: diagnosis and management.

NF-2 is an extremely rare form of neurofibromatosis (NF) characterized by central system (CNS) neural crest-derived tumors and frequently cafe au lait spots (CLS). The purpose of this study was to report the clinical and imaging findings of seven patients with this disorder and to stress that value of surgical treatment in its management. Seven patients between 8 and 32 years of age who had NF-2 were included in the study. Clinical charts, surgical and pathological findings, and imaging studies were reviewed retrospectively. Patients were followed up for to 142 months. Clinical evaluation and neuroimaging studies detected the clinical criteria of NF-2 in all patients. Two deaths occurred after surgical intervention in our series. None of the patients suffered from recurrent tumor following surgery. Our results show that NF-2 is an uncommon entity which has a good prognosis after surgical intervention, in spite of the presence of multiple cranial and/or spinal lesions.

Adolescent↗
PubMed1998

The treatment of cerebral oligodendrogliomas with particular reference to features indicating malignancy: report of seventy-seven cases.

Oligodendrogliomas are relatively rare tumors that arise from the oligodendrocyte or its precursors. The role of postoperative radiotherapy (RT) in these tumors still remains unclear. Data concerning a study on 77 histologically verified cases of oligodendrogliomas of the brain among a total number of 1884 cases of an intracranial glioma treated at the Hacettepe Medical Centre between 1964 and 1991 were reviewed and analyzed (6.5%). One patient died in the early postoperative period and 8 patients in pediatric age group with an aggressive from of the tumor died within 6 months of treatment. The results suggest that oligodendrogliomas which arise in childhood primarily in the intraventricular region should be considered potentially more malignant than other lesions of this type. Because of this, we believe that postoperative radiotherapy is necessary to prevent the recurrences.

Brain Neoplasms↗
PubMed1998

Time-level relationship for lipid peroxidation and the protective effect of alpha-tocopherol in experimental mild and severe brain injury.

OBJECTIVE: Oxygen free radical-mediated lipid peroxidation has been proposed to be one of the major mechanisms of secondary damage in traumatic brain injury. The first purpose of this study was to establish the time-level relationship for lipid peroxidation in injured brain tissue. The second purpose was to examine the protective effect of alpha-tocopherol against lipid peroxidation. METHODS: For this study, 65 guinea pigs in five groups were studied. Five of the animals were identified as a control group, and the remaining 60 animals were divided equally into four groups (Groups A, B, C, and D). Mild injury (200 g x cm) (Groups A and C) and severe injury (1000 g x cm) (Groups B and D) were produced by the method of Feeney et al. Alpha-tocopherol (100 mg/kg) was administered intraperitoneally before brain injury in Groups C and D. Five animals from each group were killed immediately after trauma, five after 1 hour, and the remaining five animals after 36 hours. Lipid peroxidation in traumatized brain tissues was assessed using the thiobarbituric acid method. RESULTS: In all groups with traumatic brain injuries, levels of malondialdehyde, a lipid peroxidation product, were higher than in the control group. The amount of lipid peroxidation was increased by the severity of the trauma. Alpha-tocopherol significantly suppressed the rise in lipid peroxide levels in traumatized brain tissues. CONCLUSION: This study demonstrates that lipid peroxidation is increased by the severity of trauma and that alpha-tocopherol has a protective effect against oxygen free radical-mediated lipid peroxidation in mild and severe brain injury.

Animals↗
PubMed1997

Multiple meningiomas of the central nervous system without the stigmata of neurofibromatosis. Clinical and therapeutic study.

Multiple meningiomas are relatively rare tumors without known neurofibromatosis. In this paper, such eight cases of multiple meningiomas as described by CUSHING and EISENHARDT are presented. Certain aspects of diagnosis and surgical management of this rare condition are discussed with particular emphasis on the importance of the distinction among multiple meningioma, meningiomatosis, or recurrences of these tumors. Fortunately, many of these patients tolerate multiple surgical interventions well, although the removal of these tumors in critical areas is a difficult problem. Thus, we think that it is important to examine and supervise all patients who have had a meningioma for a possible occurrence of a second meningioma.

Adult↗
PubMed1997

Jugular foramen meningioma. Report of a case and review of the literature.

The occurrence of a meningioma within the jugular foramen is very rare. We present the case of a 33-year-old man who presented with five-year history of hoarseness and was found to have paralysis of lower four cranial nerves on the left. High resolution computed tomography showed a dumbbell shaped tumor of the left jugular foramen extending intracranially over the jugular tubercle and extracranially into the parapharyngeal space. The patient underwent staged neuro-otological surgery and the mass was removed subtotally with no recurrence in six years. Histopathologic diagnosis was transitional meningioma. Our review of the literature revealed 33 previously reported cases. Four of these cases had neurofibromatosis. All but one underwent some form of otolaryngologic surgery. Although twenty had an intracranial component to their tumor, only 11 had a craniotomy. The majority of the tumors were meningothelial meningiomas (60%). Only two cases were malignant meningiomas. We reviewed the clinical and radiological characteristics and summarized the benefits and pitfalls of existing surgical options.

Adult↗
PubMed1996

CNS involvement of Langerhans cell histiocytosis. Report of 23 surgically treated cases.

We present 23 cases of Langerhans cell histiocytosis with central nervous system (CNS) involvement. The major complaints were a mass on the cranial vault in fifteen (65%), visual disturbance in four (16%), polyurea-polydipsia in three (13%), and progressive weakness in all extremities in one patient (4%). Neurological examination revealed no abnormality in sixteen patients (70%), cranial nerve palsy, visual field defect and optic atrophy in six (26%) and paraparesis in one (4%). Tumoral mass was found to be located on the cranial vault (65%), in the suprasellar region (21%) and in the spinal column (8%). The cranium and spinal column were both involved in one patient. All patients underwent surgery; craniectomy with grossly total tumor excision plus cranioplasty (65%), craniotomy with subtotal tumor excision (26%), and vertebrectomy with grafting (13%) were performed. The clinical, radiological and histopathological features, as well as therapeutical considerations are discussed and the pertinent literature is reviewed.

Adolescent↗
PubMed1996

Spinal injuries in the pediatric age group: a review of 82 cases of spinal cord and vertebral column injuries.

A review of 82 children with spinal cord and/or vertebral column injury treated in our department between 1968 and 1993 showed that 67% of the patients were boys and the average age was 11.4 years. The cause, vertebral level, and type of injury, and the severity of neurological injury varied with the age of the patient. The cause of pediatric injuries differed from that of adult injuries in that falls were the most common causative factor (56%) followed by vehicular accidents (23%). The most frequent level of spinal injury was in the cervical region (57%, 47 patients) followed by the lumbar region (16.5%, 13 patients). In our series, 18% of the patients had complete injury and the overall mortality rate was 3.6%. Eleven children (13%) had spinal cord injury without radiographic abnormality (SCIWORA), whereas 39 (47%) had evidence of neurological injury. Although the spinal injury patterns differed between children and adolescents, the outcome was found to be predominantly affected by the type of neurological injury (P < 0.05). Children with complete myelopathy uniformly remained with severe neurological dysfunction; children with incomplete myelopathy recovered nearly normal neurological function. Finally, the authors conclude that most spinal injuries can be successfully managed with nonoperative therapy. The literature is reviewed as to the treatment and outcome of pediatric spinal injuries.

Child↗
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

Effect of Nd:YAG laser on experimental disc degeneration. Part II. Histological and MR imaging findings.

The potential advantages of percutaneous procedures over traditional discectomy are multiple, but the use of laser energy to ablate disc tissue appears entirely empirical. To date, no experimental study exists investigating the results of laser on degenerated intervertebral disc. The present study was therefore undertaken to determine the histological and radiological changes induced by neodymium-yttrium-aluminum-garnet (Nd:YAG) laser on such disc tissue. It was shown that the vaporization of disc tissue was caused by Nd:YAG laser in early period, but this was gradually replaced by cartilaginous fibrous tissue at 60 days after laser irradiation as a result of the proliferation of cartilaginous cells and fibrous tissues. Accordingly the magnetic resonance (MR) imaging index histogram moved to the left in the early period, but it moved to the right again at 60 days after laser irradiation. In view of these data, we conclude that the use of laser in degenerated disc disease does not represent an effective treatment as an alternative to conventional surgical methods.

Animals↗
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

Microsurgical removal of a free segment of microcatheter in the anterior circulation as a complication of embolization.

Endovascular therapy for cerebral arteriovenous malformations, although generally accepted to be a safe procedure, is not without risks. We present a patient with a 20 cm free segment of a catheter in the anterior circulation as a complication of embolization. This is a very rare complication. To our knowledge, only six cases have been reported in the literature. We believe this to be the first reported case of this complication treated surgically via craniotomy and arteriotomy.

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

Giant intrasacral schwannoma forming a presacral mass: a report of an unusual cause of lumbosacral radiculopathy.

Schwannomas are extremely rare tumours deriving from cells within the neurilemma. The authors report a case of giant intrasacral schwannoma presenting in the presacral region. The tumour presented with a lumbosacral pain and it was removed totally by two-stage surgical intervention. When seen five years after the second surgical intervention, the patient was asymptomatic. The rarity of such cases prompted this report.

Humans↗
PubMed1995

Efficacy of high dose amino acid solution on spinal cord injury induced by focal Nd:YAG laser irradiation.

In this experimental study, a neodymium:yttrium-aluminium-garnet (Nd:YAG) laser was used to induce highly reproducible focal spinal cord lesions in anaesthetized guinea pigs. The efficacy of high dose amino acid solution (HDAAS) on this injury is investigated. Experiments were performed on 36 animals divided into three groups; sham operated controls, laser irradiated surgical controls, and amino acid groups. Acute responses to injury were evaluated with somatosensory (SSEP) and motor evoked potentials (MEP) and functional recovery was assessed for 8 weeks using the inclined plane technique. In the laser irradiated surgical control group, MEP disappeared one hour after the laser injury, but SSEP revealed changes of amplitude and latency. In this group, the average value of the inclined plane at 24 hours after the laser application was 45.3 +/- 1.4 degrees. In the amino acid group, at the sixth hour of injury, MEP and SSEP changes improved with infusion of HDAAS for 4 hours. This improvement was statistically significant (for latency of SSEP U = 140 p < 0.05). Inclined plane value at 24 hours after the laser application was 65.5 +/- 1.2 degrees in this group. This study showed that application of Nd:YAG laser irradiation on the spinal cord induced spinal cord injury which presented as paraparesis, HDAAS may provide significant therapeutic protection in secondary damage following this injury and may have a potential role in the treatment of acute spinal cord injury.

Amino Acids↗