PubMed Health⌕ Search

Biomedical subjects

J Bucek

Publications and source records attributed to J Bucek.

At least 37 records · Page 2Linked to original sources
PubMed1989

Expression of vimentin and glial fibrillary acidic protein in human developing spinal cord.

Expression of intermediate filament proteins was studied in human developing spinal cord using immunoperoxidase and double-label immunofluorescence methods with monoclonal antibodies to vimentin and glial fibrillary acidic protein (GFAP). Vimentin was found in the processes of radial glial cells in 6-week embryos, while GFAP appeared in vimentin-positive astroglial cells at 8-10 weeks. GFAP and vimentin were present in approximately equal amounts in differentiating astrocytes in 23-week spinal cord. In 30-week fetuses, astrocytes reacted strongly for GFAP, while both the reaction intensity and the number of vimentin-positive cells fluctuated predominantly in the grey matter. No clear-cut transition from vimentin to GFAP was noticed during the development of astrocytes. The majority of ependymal cells in 23-week fetuses contained vimentin but only a few of them reacted for GFAP. The expression of vimentin continued during the whole development of the ependymal layer, in contrast to the reactivity for GFAP which disappeared between the 30th week and term.

Antibodies, Monoclonal↗
PubMed1986

[Contribution of electron microscopy in the differential diagnosis of tumors of the meninges, brain and spinal cord].

Critical Evaluation of 200 tumours of meninges, brain and spinal cord showed that to be familiar with the ultrastructural features of meningioma and its variants was instrumental in differential diagnosis of other primary or secondary meningeal tumours (neurinoma, paraganglioma, xanthomatous and histiocytic tumours). A limited value of electron microscopy was found in astrocytoma and glioblastoma in contrast to its importance in low-differentiated ependymoma and oligodendroglioma. The examination had histogenetical and taxonomic values in medulloblastoma (CNS neuroblastoma and mixed tumours with a component featuring primitive neuroectodermal or neuroblastic differentiation). Ultrastructure was very important in the so-called primitive neuroectodermal CNS tumours where only the lack of conspicuous glial or neuroblastic differentiation confirmed the diagnosis. Electron microscopy was instrumental in rare primary CNS lymphomas as well as in some metastatic tumours.

Brain Neoplasms↗
PubMed1984

The submicroscopic structure of a chondroblastic osteogenic sarcoma.

Two patients are reported with a chondroid form of osteosarcoma, whose structure was also analyzed submicroscopically. The clinical and radiologic picture and the rapid lethal progress of the disease indicated an osteosarcoma, while both histologic and electron-microscopic investigation suggested the prevalence of malignant chondroid. Progress in the treatment of osteosarcoma makes it essential for diagnostic, therapeutic and prognostic reasons to reintroduce subclassification of these tumors in an attempt to correlate their morphological picture with their biologic properties. According to our experience to date, it seems that the cartilaginous component in no way ameliorates the rapid malignant penetration of the osteosarcoma. It is essential to distinguish these tumors from the usually much less malignant chondrosarcomas and to place the chondroblastic osteogenic sarcoma among in spite of the clear predominance of the malignant chondroid, and thus also introduce highly radical and combined therapy.

Adolescent↗
PubMed1981

Influence of charcoal haemoperfusion on platelet count in acute poisoning and during regular dialysis treatment.

Platelet count did not significantly decrease after charcoal haemoperfusion in patients with acute poisoning and significantly decreased during regular dialysis treatment. Adherent platelets and leucocytes were found on the surface of granules after haemoperfusion using a scanning electron microscope. Decreased platelet count returned to the original level at 48 to 72 hours after charcoal haemoperfusion.

Acute Disease↗
PubMed1978

Establishment of cell line derived from human malignant melanoma.

A new human cell line of malignant melanoma (MJM) was established with the use of the in vitro fragment technique. It has been maintained over 34 months of continuous cultivation. Three types of cells can be recognized by light microscope. The epitheloid elements predominate, less frequent are fibroblastoid and giant multinuclear cells. The pigment production is not macroscopically visible. Over 60 per cent of analyzed metabphases showed hyperdiploid number of chromosomes, the rest was mostly tetra and hexaploid. No marker chromosomes were detected. The growth studies indicate the MJM cells have 63-hr doubling time. Cytochemistry revealed positive pigment or propigment granules in 36 per cent of cells. Ultrastructural studies did not detect melanin granules but some particles resembling atypical premelanosomes and melanosomes were recognized in some sections.

Cell Cycle↗
PubMed1977

[Ultrastructural findings in the so-called minimal glomerular changes].

Fifty-eight needle biopsies of the kidneys with the light microscopical diagnosis of so-called minimal glomerular lesions were subjected to ultrastructural evaluation. The series contained children and adults under 25 years of age with the mean age of 16.9 years. The most frequent findings were those of the glomerular epithelia: vacuolation and swelling of their cytoplasm in 72.8%, microvilloustransformation in 13.6%. Endothelial lesions were less frequent: swelling and vacuolation of their cytoplasm occurred in 46.6%. The most important ultrastructural lesions appeared to be the mesangial ones. Focal increase in the mesangial matrix was seen in 44.8% and small intralobular scars in 13.6%. True focal increase in mesangial cells was rare (6.9%). The formation of duplicatures of the basement membranes in the glomeruli was exceptional (3.6%). Another important ultrastructural finding was a focal thickening of the basement membrane in a larger number of cases (32.3%). Deposits were found rarely (7 cases, 12.1%) most of them occurring in the mesangium. The cellularity of the glomeruli did not exceed the normal range.

Biopsy↗