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Biomedical subjects

B Bednár

Publications and source records attributed to B Bednár.

12 recordsLinked to original sources
PubMed1979

Lymphoepitheloid cell malignant lymphoma (Lennert).

Typical epitheloid cell formations were found in 175 of 500 cases of various types of Hodgkin's disease. No distinctive behaviour was found in cases with epitheloid structures. Close attention has been devoted to a further series of 23 lymphoepitheloid cell malignant lymphomata marked by focal nuclear atypicality in their epitheloid cell granulomas, which destroyed the basic neoplastic structure of the lymph node in many cases, necessitating further biopsy. In this series not only Hodgkin's disease (7 cases) but also some malignant lymphomas of non Hodgkin's types (3 x immunoblastoma, 3 x immunocytoma and 2 x T-lymphoblastoma) were found. In 6 cases only a tentative diagnosis of lymphoepitheloid cell malignant lymphoma could be made. The epitheloid granulomatous reaction tended to disappear gradually in all cases by repeated check-ups, and was apparently a secondary phenomenon. The cause of the epitheloid cell atypia was not evident although it proved to be an important diagnostic feature identifying an independent form of lymphoepitheloid malignant lymphoma. The subsequent development of this lesion suggested a mildly pleiomorphic highly malignant lymphoma, which might be of B cell origin, but sometimes demonstrably of the T cell series.

Diagnosis, Differential↗
PubMed1979

[Clear-cell sarcoma with melanin].

Melanin was proved in the tumorous cells in a 62-year-old man who had a malignant tumor with the structure of clear cell sarcoma of tendons on the sole of the foot. Electronoptic examination confirmed the presence of numerous melanosomas and their complexes. Although the tumor may be regarded as a special variant of melanoblastoma from clear cells (7), the authors give reasons admitting an independent position within the clear cell sarcoma of tendons.

Foot Diseases↗
PubMed1979

[Possibilities for improvement in the histocytological comparison of tumor elements].

Pappenheim's staining is indispensable for comparisons between cytological and histological pictures in oncology. A well-stained tumour tissue section then offers advantages similar to that of smear cytological pictures without loss of syntopic relationships. For general pictures, however, haematoxylin-eosin taining offers most advantage.

Czechoslovakia↗
PubMed1978

[Use of various technics in the classification of hematopoietic system tumors].

A comparison of three groups classified according to three different methods (89, 91, und 278 cases respectively) confirmed that the main oncological features of haematopoietic tissue tumours should be sought in their cytological-histological properties.--The spectrum of methods employed (histochemistry, immunohistology, electron microscopy) may in individual cases underpin the decision-making process especially when the appearance of tumour cells has been altered by advanced anaplasia. Partial results of these methods judged in isolation may, however, be conductive to wrong interpretation. That is why special significance should be attached to thin sections of tissue stained according to Giemsa as they combine the advantage of histology with those of cytology.--In the basic classification the pathologist can do with the conventional haematological classes of tumours (granulocytic, histiomonocytic, lymphocytic, erythrocytic, megakaryocytic, mixed, and unclassifiable). In the lymphocytic series it was necessary to proceed not only according to immaturity but also according to the blastic transformation of the initial elements.--The principal outstanding problem is that of a positive mutual distinction between blastically transformed lymphocytes and between those and cells of the reticulum.

Hematopoietic System↗
PubMed1978

[Electron microscopy as a method of classification of hematopoietic-system tumors].

83 biopsies of lymph nodes and 35 specimens of blood in different types of haematopoietic system oncological involvement were examined electronoptically with a view to finding distinguishing features such as would prove to be better than other methods used in diagnosing the above tumours. In the granulocytic series these proved to be granules though there was a loss of their formation in most of the poorly diagnosable processes. However, it proved to be relatively easy to make use of tests for phagocytosis in myelomonocytes. In the histiocytic series the defining features (phagocytosis and proteosynthesis) proved to be too general in nature to find any relevant use in oncological diagnosis. On the other hand, the rod-like granules of Langerhans' cells proved to be a reliable guide in diagnosing histiocytosis X similarly as the Weibel-Palade granules did in diagnosing endotheliosis. In the lymphocytic series, B series diagnosis can be facilitated by the presence of spatially arranged interdigitations; in the T series interdigitations are either missing or else are arranged in a single plane only. The erythrocytic series is defined by the presence of ferritin while megakaryocytes are defined by the phenomenon of fissure-like communications.--All those features were merely supplementary in nature and could not be used as an independent diagnostic method particularly in view of the small volume of the processed specimens as these did not always contain representative material or else supplied it in a hardly classifiable mixture.

Hematopoietic System↗
PubMed1977

Biological characteristics of peptidoglycans of group A streptococcus and some other bacterial species. I. Tolerance and effect of antibody in fever response, and heart damaging effect in rabbits.

Induced tolerance to the pyrogenic action of group A streptococcus peptidoglycan decreased after one week and was no longer detectable after the second week. However, one or two further doses of peptidoglycan rapidly restored the tolerance. The passive transfer of plasma from rabbits tolerant to streptococcus peptidoglycan to nontolerant animals failed to transfer tolerance. Antiserum to streptococcus peptidoglycan neutralized the pyrogenic effect of not only streptococcus but also staphylococcus and pneumococcus peptidoglycan; it did not influence the febrile response to endotoxin. Histopathologic changes in the rabbit heart produced by the intravenous injection of staphylococcus or pneumococcus peptidoglycans were similar and were characterized by various stages of degeneration and necrosis. The changes were less pronounced than after streptococcus peptidoglycan. Antiserum to streptococcus peptidoglycan had modest or no counteracting effect on the development of heart alterations after staphylococcus or pneumococcus peptidoglycan.

Animals↗
PubMed1975

[Progressive multifocal encephalitis (PML)].

In four cases of progressive multifocal leucoencephalitis the basic disease was always a malignant lymphogranuloma. Changes in the brain were multifocal, however the frontoparietal area of the white matter was affected most frequently and foci in this part were oldest. In these foci demyelination with atypical astrogliosis predominated, and there was a very small number of scavenger cells. At the periphery of foci always proliferation and enlargement of homogenous oligodendroglia nuclei were found sometimes with inclusions which in immunoassay sometimes had a common antigen with papovirus SV 40 and on electronoptic examination always contained many virions of the papovirus. No direct relationship was found between the duration of the neoplastic process, its type and changes in the CNS.

Adult↗
PubMed1975

[Electron microscopy demonstration of the myoblastic origin of various tumours].

In the histogenetic classification of spindle-cell tumours, in particular malignant ones, it is an advantage to use electronoptic examination. It proves useful in particular in the diagnosis of tumours of myoblastic origin. Inadequate formol fixation of bioptic material in this group does not matter too much and does not alter diagnostic structures which was proved by four illustrative observations (an angioleiomyoma of the subcutaneous layer, congenital generalised fibromatosis with a muscular component, rhabdomyocellular sarcoma of the urinary bladder, alveolar rhabdomyosarcoma).

Adult↗