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O Barlas

Publications and source records attributed to O Barlas.

At least 19 recordsLinked to original sources
PubMed2003

Formalin fixing and paraffin embedding may lead to extra band development in PCR.

The molecular biological analysis of infectious agents requires the availability of a reliable source of microorganisms to be used to recover DNA. Clinical samples can be obtained directly from infected patients or can be propagated using in vitro or in vivo systems. However, repeated sampling from patients is not always possible as the procedure may be invasive or unpleasant, or it is not possible to catch the same agent at the time of second sampling. Moreover, the techniques used may also produce false-positive and false-negative results. We therefore studied the impact of formalin-fixing and paraffin embedding on tissue sampling, and the methodologies such as DNA isolation and PCR amplification of DNAs from archival materials in the diagnosis of Mycobacterium tuberculosis. PCR analyses were done according to standard methods with some modifications. Demonstration of mycobacteria was successful both in tissue sections of the formalin-fixed lymph nodes and in stained fresh materials from patients. However, the results showed the presence of two extra bands in the gel. We accounted for extra band development due to the harshness of the methodology used to isolate nucleic acids from formalin-fixed and paraffin embedded tissue samples or the nature of the fixation procedure, or because of the time passed during storage in which alteration in the chromosomal DNA would take place. Thus, if disease- and tissue specific morphological features, such as sample size, type of fixation, and intralesional heterogeneity are ignored, errors because of sampling and methodologies used may lead to false-positive and false-negative results.

Artifacts↗
PubMed2001

Do unilateral ablative lesions of the subthalamic nucleu in parkinsonian patients lead to hemiballism?

We report the safety results in nine patients with advanced idiopathic Parkinson's disease (PD) who underwent ablative surgery of unilateral subthalamic nucleus (STN). In eight patients, surgical objectives were attained without induction of abnormal involuntary movements or other adverse effects. One patient developed transient hemiballistic movements which improved within 2 weeks after surgery. Assessment at 2 weeks to 20 months postoperatively revealed no long-term adverse effects. We conclude that hemiballism following unilateral ablation of STN in patients with PD is a rare phenomenon, and unilateral ablative lesions of STN can be performed safely.

Adult↗
PubMed2001

Long-term follow-up and results of thirty pediatric intracranial hydatid cysts: half a century of experience in the Department of Neurosurgery of the School of Medicine at the University of Istanbul (1952-2001).

A series of 30 documented cases of intracranial hydatid cyst out of 33 pediatric and 45 total patients admitted to the Department of Neurosurgery of the School of Medicine at Istanbul University within the years 1952-1996 is presented. The pediatric population consisted of 73% of the series. Twenty patients (66%) are alive and well after a follow-up period of 8-45 years (mean 21.5 years). Six patients (20%) died and 4 (13%) were lost to follow-up. There were 3 early postoperative deaths (10%), 2 being in the pre-CT era. In 4 cases (13%), brain involvement was secondary, and 2 cases (7%) had multiple intracranial hydatid cysts. Age ranged from 4 to 16 years, with a mean of 10.4. There were 5 intraventricular (17%) and 2 (7%) intracranial extradural settlements. No children with posterior fossa hydatid cyst, primary skull hydatidosis or concomitant spinal involvement were detected. One patient (3%) presented with "rhinorrhea" which in fact was a hydatid fluid leak. Preoperative pseudocerebellar syndrome, convulsion and extrapyramidal signs were seen in 6 patients each (20%). Five patients (17%) had permanent visual deficits, 3 being in pre-CT era. Out of 29 patients operated on, hydatid birth with intact cyst removal was achieved in 18 cases (62%), with no other manipulation needed. This rate has increased to 70% in the CT era. Intraoperative accidental rupture occurred in 8 cases (28%), of which 7 were localized frontally or had a frontal involvement (88% of the ruptured cases). Of the patients with intraoperative rupture, 5 are dead (63%) and they were all primary. In contrast, all 3 cases alive with intraoperative rupture are secondary. Three cases were punctured on purpose (10%). Four of the operated patients (14%) required long-term antiepileptic therapy, 3 having no preoperative seizures. Only 1 patient required a shunt (3%). Four cases had recurrence, all with intraoperative cyst rupture (14%). The long-term evaluation of the results yielded an overall mortality rate of 21%. Routine use of CT after the 80s decreased the rate to 14%. With the analysis of 50 years of data, it is strongly concluded that brain involvement in pediatric hydatid disease is a primary process if delayed diagnosis and insufficient treatment of extraneural hydatidosis are prevented.

Adolescent↗
PubMed2000

Interstitial irradiation for craniopharyngioma.

The results of interstitial irradiation treatment for craniopharyngioma in two patients with six year follow-ups are presented. Stereotactic interstitial irradiation with Iodine-125 sources as sole therapy was employed in two adult patients who refused surgical resection. The diagnoses were confirmed by stereotactic biopsy. The first tumour which underwent interstitial irradiation was solid and 4 cm in diameter, and the second, 2.7 cm in diameter, had both cystic and solid components. The implanted Iodine-125 seeds delivered 67 Gy and 60 Gy to tumour periphery at the rate of 12 and 14 cGy/h, respectively, were removed at the end of designated radiation periods. Tumour shrinkage and central hypodensity, first observed 3 months after irradiation, continued until one tumour shrank to less than 1 cm at 12 months, and the other disappeared completely at 24 months. In both cases functional integrity was restored, and neither radiation induced toxicity nor recurrence has occurred six years after treatment. The results in these two cases suggest that solid craniopharyngiomas are sensitive to interstitial irradiation.

Adult↗
PubMed2000

Non-resective management of pineoblastoma.

The results of a non-resective treatment approach for pineoblastoma comprising stereotactic biopsy, cerebrospinal fluid diversion, and fractionated radiotherapy in six patients over a period of six years are presented. There were three male and three female patients, with a median age at diagnosis of 20 years. Magnetic resonance imaging of the spine, ventricular cerebrospinal fluid cytology, and tumour markers in cerebrospinal fluid were negative. Tumour response to initial radiotherapy was complete in three patients and partial in three patients. Recurrences were treated with interstitial irradiation with iodine-125 seeds in four instances, repeat radiotherapy when time elapsed was more than five years in one instance, with surgical resection in two instances, and chemotherapy in two instances. The diagnostic and therapeutic effectiveness of this management strategy is assessed. There were no complications related to surgical procedures. The median follow-up time was 48 months (range 14-70 months). Five patients were alive at 14, 45, 51, 57, and 70 months of follow-up. One patient died of disease at 28 months following diagnosis. The overall survival rate was 80 % +/- 17.89 % at 28 months. The results of this study suggest that this non-resective treatment approach is acceptable as an initial treatment alternative to radical surgical resection of pineoblastomas.

Adolescent↗
PubMed1999

Stereotactic surgery in the management of brain abscess.

BACKGROUND: Bacterial brain abscesses can be diagnosed and treated with stereotactic aspiration. METHODS: From 1991 to 1997 we have used computed tomography-guided stereotactic aspiration to diagnose and treat 21 patients with a total of 58 bacterial brain abscesses. The ages of the patients ranged from 4 to 72 years (median 25 years); 11 of these 21 patients had multiple abscesses. The number of abscesses per patient with multiple abscesses ranged from 2 to 9, all located deep in subcortical white matter. RESULTS: All patients underwent stereotactic surgical drainage and an 8-week intravenous antibiotic medical treatment. Of the 58 abscesses, 23 were aspirated. Of these 23 abscesses, 19 were radiologically stage III or IV and four were stage I or II. Pathological examination confirmed radiological staging in 19 patients (83%). Except for the three patients who have mild residual hemiparesis and one patient recovering from ataxia, all patients had complete neurological recovery. CONCLUSIONS: Computed tomography-guided stereotaxy achieved all the objectives of management; namely, ascertaining the diagnosis, draining the content of the mass, and obtaining pus for accurate bacteriological diagnosis without morbidity. Stereotactic aspiration combined with an 8-week intravenous antibiotic regimen has yielded an effective therapeutic result in all of our abscesses, small or large, solitary or multiple, superficial or deep-seated. A high radiological-pathological correlation was also deduced from this study.

Adolescent↗
PubMed1997

Three unusual cases of intracranial hydatid cyst in the pediatric age group.

Three unusual cases of hydatid disease with central nervous system involvement are reported in the pediatric age group: a 9-year-old boy with a total number of 12 intracranial secondary hydatid cysts; a 13-year-old girl admitted in areflexia who survived after cyst puncture and successive mass removal, and a 14-year-old boy with a huge intracranial hydatid cyst weighing 770 g which was extracted without rupture. The article discusses the surgical problems, and the related literature is reviewed.

Adolescent↗
PubMed1996

A serial CT scan and MRI verification of diffuse cerebrospinal gliomatosis: a case report with stereotactic diagnosis and radiological confirmation.

Gliomatosis cerebri is an infrequent tumor of neuroepithelial origin presenting with deterioration of cognitive functions, behavioral and mental changes, motor weakness, headache, and seizures. Laboratory data are unconclusive. MRI appears to be the imaging modality of choice and mainly reveals a bilateral and diffuse infiltration of midline adjacent brain structures whose anatomical configuration remain intact. MRI- or CT-guided stereotactic biopsy is advised as the diagnostic procedure in suspected cases. A 9-year-old girl with diffuse cerebrospinal gliomatosis, investigated with sequential cranial CT scans, and MRI-verified spinal cord involvement is reported, and the corresponding literature is reviewed.

Biopsy↗
PubMed1995

Evaluation of response to postradiation eight in one chemotherapy in childhood brain tumors.

Ten children, 3 to 15 years of age with high risk primary brain tumors were treated with postradiation 'eight in one' chemotherapy; vincristine, lomustine, procarbazine, hydroxyurea, cisplatin, cytosine arabinoside, cyclophosphamide and methylprednisolone. The tumors comprised of three medulloblastomas, two primitive neuroectodermal tumors, one ependymoblastoma and four anaplastic ependymomas. Treatment involved surgery (two total resection, six subtotal and two biopsy only) followed by conventional radiotherapy (primary tumor: 50-54 Gy, whole brain: 30-45 Gy, and spinal axis: 25-36 Gy). Objective tumor response with radiotherapy was achieved in 7 of 9 patients (78%) (6/8 patients with residual tumor and one patient with complete resection but positive cerebrospinal fluid cytology). Complete response was attained in 4 of 9 patients (44%). 'Eight in one' chemotherapy was initiated four weeks after radiation and repeated at 4 weekly intervals for 5-8 courses. Postradiation 'eight in one' failed to show any additional effect on tumor responses. Median survival was 34 months (range 9-48 months) with five of ten patients alive: four in complete and one in partial remission. All the five survivors were among the patients who had achieved response to initial treatment. This result suggested that degree of response to initial treatment might determine subsequent outcome and thus the choice of modality for initial therapy might be important.

Adolescent↗
PubMed1995

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History, 20th Century↗
PubMed1994

Bromocriptine-induced cerebrospinal fluid fistula in patients with macroprolactinomas: report of three cases and a review of the literature.

Bromocriptine therapy for macroprolactinoma induced cerebrospinal fluid (CSF) rhinorrhea in three patients. The tumor had extended well beyond the sella turcica and caused bony erosion in all the cases. All three patients responded to bromocriptine therapy rapidly. CSF fistula occurred concomitantly with the reduction of tumor size and caused meningitis in two of the patients. Withdrawal of bromocriptine resulted in cessation of the leakage. One of the patients underwent transsphenoidal repair. Two patients refused surgery. This potentially lethal complication encountered in these three cases demonstrates the need for close supervision of macroprolactinoma patients with skull base erosion placed under bromocriptine therapy.

Adult↗
PubMed1993

Tethered cord in the adult mimicking the lumbar disc syndrome: report of two cases.

Two adult patients with tethered cords whose symptoms mimicked those of lumbosacral intervertebral disc herniation are reported. Neither one of the patients had cutaneous stigmata, and one had normal plain x-ray examination of the spine. Magnetic resonance imaging in both patients demonstrated tethering of the cord. Untethering of the cord resulted in disappearance of the symptoms in both patients. These unusual cases suggest that tethering of the cord must be included in the differential diagnosis of the herniated lumbar intervertebral disc syndrome.

Adult↗
PubMed1986

Alveolar hydatid disease of the brain. Report of four cases.

Four cases of alveolar hydatid disease of the brain encountered within 27 months in eastern Turkey are reported. All of the patients were male farmers who presented with signs of cerebral tumor. Two of the patients were shown to harbor hepatic lesions and one of them had pulmonary metastases. The cerebral lesions were removed in toto and neurological recovery was obtained in all four patients. A review of the literature revealed only five previously reported cases treated surgically. It is concluded that cerebral Echinococcus multilocularis lesions are amenable to surgery, and that their removal provides useful prolongation of life despite the presence of hepatic or pulmonary disease.

Adult↗
PubMed1984

Supratentorial intracerebral schwannomas.

A case of frontotemporal intracerebral schwannoma in a 16-year-old girl with epilepsy and progressive hemiparesis of 3 years' duration is described. The histologic diagnosis and possible sites of origin are discussed. In addition, five previously reported cases of supratentorial intracerebral schwannoma are discussed. All of the patients reviewed presented with epilepsy early in life, and there was no association with neurofibromatosis.

Adolescent↗
PubMed1984

Primary dural melanomas: report of two cases and review of the literature.

Two cases of primary melanoma of the central nervous system originating from the dura mater and without involvement of the leptomeninges are described. In one case, the tumor was located extradurally with firm attachment to the dura mater and dural melanosis. In the other case, the dura was involved diffusely with multiple discrete masses of 1 to 3 mm in diameter. A literature review revealed five other cases of primary dural melanoma. A discussion of the origin of primary dural melanoma is presented.

Adolescent↗