Biomedical subjects

M Zabek

Publications and source records attributed to M Zabek.

At least 19 recordsLinked to original sources

PubMed2006

Age and bromodeoxyuridine labelling index as prognostic factors in high-grade gliomas treated with surgery and radiotherapy.

AIMS: To determine the prognostic value of proliferative potential and DNA ploidy in 72 brain tumours (36 grade III and 36 grade IV astrocytomas) using bromodeoxyuridine (BrdUrd) incorporation and flow cytometry. MATERIAL AND METHODS: All 72 patients underwent excision, mostly incomplete of the tumour. After surgery, eight patients received conventionally fractionated radiotherapy, 11 patients received accelerated radiotherapy, and 53 patients received hypofractionated radiotherapy. Tumour samples taken during surgery from each patient were incubated in vitro for 1 h at 37 degrees C with BrdUrd using the high pressure oxygen method. The percentage of BrdUrd-labelled cells (BrdUrd labelling index [BrdUrd LI]), and the total DNA content were evaluated: RESULTS: The tumours showed variability in the BrdUrd LI values, which ranged from 0.3 to 19.1%. No difference was observed in mean BrdUrd LI between grade III and grade IV sub-groups. A significantly higher percentage of DNA aneuploidy was observed in grade III gliomas (69.4%) than in grade IV gliomas (52.8%). Univariate analysis showed that younger patients (< or = 51 years) (P = 0.021) with grade III gliomas (P = 0.030) and low tumour proliferation rate (BrdUrd LI < or = 2.7%, P = 0.028) had significantly higher 5-year survival rates. Tumour ploidy had no influence on patients' survival (P = 0.591). However, Cox multi-variate analysis showed that only age over 51 years, and high tumour proliferation rate (BrdUrd LI > 2.7%), were significant unfavourable prognostic factors in patient survival. CONCLUSION: In this study, independent prognostic factors for patients with high-grade gliomas treated with surgery and post-operative radiotherapy are age and tumour proliferation rate assessed according to the BrdUrd LI.

Adult↗

PubMed2001

Phenotypic characteristics of GFAP-immunopositive oligodendroglial tumours Part I: immunohistochemical study.

Oligodendrogliomas are believed to derive from oligodendrocyte lineage but the expression of different immunohistochemical markers indicates some variability in their differentiation potency. It has been documented that some heterogeneity of the tumour cells exists and that oligodendrogliomas can display a spectrum of histological, immunohistochemical and fine structural features. The expression of glial fibrillary acidic protein (GFAP) in various types of neoplastic cells in oligodendroglial tumours has been well established, however the nature of these cells in relation to tumour malignancy remains controversial. The current histopathological and immunohistochemical study (with a panel of antibodies for GFAP, vimentin, S-100 protein, MBP, NSE) has been performed on biopsy specimens from 12 cases of GFAP-immunopositive oligodendroglial tumours to evaluate their phenotypic characteristics. The majority of tumours showed a variable pattern of GFAP expression in morphologically different tumour cells responding to typical neoplastic oligodendrocytes (gliofibrillary oligodendrocytes-GFOC), miniature form of gemistocytes (minigemistocytes) and neoplastic or reactive astrocytes. The majority of cases exhibited negative staining for vimentin whereas there was no evident correlation between GFAP expression and other immunohistochemical markers. The present immunohistochemical findings support the opinion that the majority of GFAP-positive neoplastic cells in oligodendroglial tumours represent the transitional cell types between oligodendroglial and astrocyte lineage. The difficulties in differential diagnosis of oligodendroglial tumours exhibiting the various patterns of GFAP expression are emphasised.

Adult↗

PubMed2001

Phenotypic characteristics of GFAP-positive oligodendroglial tumours. Part II: ultrastructural study.

Five cases of anaplastic oligodendrogliomas containing numerous GFAP-positive cells have been analysed by electron microscopy to establish the fine structural characteristics of neoplastic cells. Ultrastructurally, all tumours have revealed monotonous appearance typical of oligodendrogliomas, however some structural variability, particularly with reference to astrocytic differentiation, has been observed. The majority of neoplastic cells have shown the fine structural features of oligodendrocytes, accompanied by various numbers of intermediate cytoplasmic filaments. These filaments have been usually distributed in the perinuclear, less often in the peripheral, parts of the cytoplasm. The cells exhibiting features common to both oligodendroglial and astroglial cells might be regarded as an intermediate morphological form between these two cell types. True neoplastic astrocytes could be encountered only sporadically. The present electron microscopic studysupports the opinion that GFAP-positive oligodendroglial tumours contain heterogeneous neoplastic cell populations with the transitional cell types between oligodendroglial and astroglial lineage.

Brain Neoplasms↗

PubMed2001

Disseminating histologically benign multiple papilloma of the choroid plexus: case report.

A rare case of extensively disseminating multiple benign choroid plexus papilloma is shown. The patient first reported with high-grade hydrocephalus and two tumours in the 3rd and 4th ventricle was treated by atrioventricular shunt insertion, subtotal resection of the 4th ventricle tumour, and adjuvant 60Co irradiation of the posterior fossa. The dissemination that followed was revealed by computerised tomography and magnetic resonance imaging, and involved both the supra- and infratentorial ventricular systems, spinal canal, and brain parenchyma. Three years after the resection of the 4th ventricle tumour, the patient underwent excision of a temporal lobe lesion for relief of neurological symptoms, but showed no improvement and died 5 years after the primary diagnosis of CNS tumour. An autopsy was not performed. Analysis of the primarily resected mass showed distinct papillary pattern with no anaplasia, mitoses, multinucleation orgiant cell formation, and cytokeratin positivity at the absence of vimentin and glial fibrillary acidic protein. Analysis ofthe temporal lobe tumour again showed definite papillary formation with no signs of malignisation and virtually no mitotic figures, and the presence of cytokeratin, but not vimentin or glial fibrillary acidic protein. On both occasions, the diagnosis was choroid plexus papilloma (WHO grade I).

Brain↗

PubMed2000

Disseminated spinal and cerebral ependymoma with unusual histological pattern: clinicopathological study of a case with retrograde tumor spread.

The subject of this study is a case of anaplastic ependymoma originally arising from the central canal of the lower spinal cord followed by the 13 years history of events of upper spinal dissemination and retrograde intracranial spread. The specimens from four subsequent surgeries generally displayed the same microscopic features of neoplastic tissue and were consistent with the diagnosis of anaplastic ependymoma. The histological diagnosis was based upon the high cellularity, considerable nuclear atypia and pleomorphism, brisk mitotic activity, focally exhibited vascular endothelial proliferation and extensive necrosis. Apart from the typical pattern of ependymoma, the tumors contained areas composed almost entirely of large, uniform clear cells or pseudogemistocytes indicating the morphological heterogeneity of neoplastic cells population. The surgical specimens from four surgical resections shared light microscopic similarities suggesting spinal and intracranial dissemination from the primary spinal tumor. Since the retrograde spread via the cerebrospinal fluid (CSF) pathway is extremely rare, the authors of this study discuss the mechanism of such way of tumor metastases.

Adult↗

PubMed2000

Influence of intraoperative using of recombinant tissue plasminogen activator on the development of cerebral angiospasm after subarachnoid haemorrhage in patients with ruptured intracranial aneurysms.

For a few years conducted experimental studies and clinical trials set one's hopes on the role of the fibrynolytic treatment using recombinant tissue plasminogen activator (rt-PA) in preventing cerebral vasospasm. In our study the target population was 45 patients with ruptured saccular aneurysms causing severe SAH. In the group of 24 patients treatment consisted of a single intraoperative injection of 10 mg of rt-PA into the opened basal subarachnoid cisterns following aneurysm clipping. The patients underwent surgery with aneurysm clipping within 72 hours from subarachnoid haemorrhage in all patients. Control group of 21 patients underwent early operation after SAH and rt-PA was not given. All patients had significant basal cistern blood accumulation seen on CT scans preoperatively according to Fisher's grade III. Patients in our study were classified in clinical grade I and II according to classification of Hunt/Hess. Transcranial Doppler Daily examinations in postoperative course were performed in all patients. The postoperative results were evaluated according to Glasgow Outcome Scale. Postoperatively patients were evaluated by daily transcranial Doppler and serial CT scans. TCD demonstrated reduction in the development of vasospasm to a greater degree in the rt-PA treated group. Serial CT examinations demonstrated radical blood clot removal in all rt-PA treated patients. The postoperative results according to the Glasgow Outcome Scale in the rt-PA treated group were as follow: 22 patients were grades I and II, 2 patients were grade III. In the control group 13 patients were grades I and II, 6 patients were grade III, and 2 patients died. In the rt-PA treated group only one patient presented delayed ischemic deficit.

Adult↗

PubMed1999

Dysembryoplastic neuroepithelial tumor. A case report.

Dysembryoplastic neuroepithelial tumor (DNT) is a rare, benign tumor encountered in the cortex. It is characterized by the presence of cells of different histogenesis. Due to its mixed nature (glial-neuronal), WHO histological classification of brain tumors included it into the group of neuronal and glial-neuronal mixed tumors. Case of tumor in a 19-year-old woman experiencing for three years seizure of temporal lobe epilepsy is presented. A cranial magnetic resonance imaging (MRI) showed "pseudocystic" tumor in temporal lobe. Histological and immunocytochemical examinations of the tumor fragment removed during surgery revealed large numbers of neuronalglial nodules occurring in the cerebral cortex. Columns of glial-neuronal structures crossing parallely to the cortex surface, surrounded by oligodendrocyte-like cells (OLC) were a characteristic feature of the tumor texture. In the tumor interstitium, "floating" maturated, dysplastic-free ganglionic cells were visible in numerous bright spaces. In addition, numerous lobuliform--structured areas consisted of oligodendrocyte-like cells. Oligodendrocyte-like cells were characterized by positive immunoreaction to the presence of S-100 protein and synaptophysin. Basing on clinical manifestation and histopathological findings dysembryoplastic neuroepithelial tumor was diagnosed.

Adult↗

PubMed1999

Giant cervico-thoracic schwannoma with long clinical history. Case report.

An unusual case of a giant intraspinal schwannoma in a 45-year-old woman with 14-year history of preoperative symptoms was presented. MRI of the spine revealed an intradural, extramedullary tumor extending from the intervertebral space C4/C5 to T4 vertebral body level (2 x 1.2 x 12 cm) and filling almost the entire spinal canal. Microscopical examination showed a typical neurinoma pattern with two distinct zones of Antoni A and Antoni B tissue. Some areas exhibited nuclear atypia and hyperchromasia reflecting the degenerative changes in this slowly growing nerve sheath tumor. A rich pericellular reticulin network was seen in the areas composed of Antoni A tissue. Immunohistochemically, the tumor cells were strongly positive for S-100 protein. The diagnostic difficulties in the presented case of longstanding schwannoma resulted in the late surgical treatment. The importance of the early diagnosis of spinal nerve sheath tumors for the patient's quick recovery is stressed.

Cervical Vertebrae↗

PubMed1998

Multilocular cysticeral and hydatid cysts of the brain: a report of three cases.

Three cases of multilocular parasitic brain cysts are presented; two cases of specific form of neurocysticercosis and one case of multilocular hydatid cyst. MRI shows features seen in other cystic lesions of the CNS. In all cases the diagnosis was established by neurosurgical brain biopsy. The authors indicate that the parasitic disease should be taken into consideration in differential diagnosis of tumor-like cystic brain lesions.

Adult↗

PubMed1998

Middle superficial cerebral vein.

The microanatomical study present the anatomy of the middle cerebral vein. On the basis of the anatomical data we distinguished concentric and nonconcentric types of tributaries of the middle superficial cerebral vein. The nonconcentric type prevails.

Cerebral Veins↗

PubMed1997

Embryonal carcinoma of the pineal gland with yolk sac tumor differentiation. A case report.

Twenty three old male patient was diagnosed as a pineal gland tumor and was operated in neurosurgical ward. He died four weeks later due to pneumonia and respiratory failure. Clinical diagnosis was based on computer tomography (CT) and magnetic resonance image (MRI) examination. Histological study of a biopsy and autopsy specimens showed embryonal carcinoma with yolk sac tumor differentiation. The diagnosis was supported by positive cytokeratin, placental alkaline phosphate and alpha-fetoprotein immunostainings.

Adult↗

PubMed1996