A contribution to the comparative morphology of nucleolar apparatus of lymphocytes in the peripheral blood of man and some mammals.
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Adult↗
Biomedical subjects
M Beran
Publications and source records attributed to M Beran.
Cultivation of animal cells in a chamber employing the continuous flow of plasma from extracorporeal circuits.
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Animals↗
A novel c-abl protein product in Philadelphia-positive acute lymphoblastic leukaemia.
Activation of cellular proto-oncogenes as a result of chromosomal abnormalities has been implicated in the development of some human malignancies. Perhaps one of the most striking examples of this association occurs in chronic myelogenous leukaemia, where the Philadelphia (Ph) translocation results in substitution of the 5' end of the c-abl proto-oncogene with bcr gene sequences. A unique hybrid bcr-abl message is produced. As the Ph translocation is also present in some patients with acute lymphoblastic leukaemia, we initiated studies to determine if similar genomic events occur in these two different forms of Ph-positive leukaemia. Here we report that the Ph translocation in acute lymphoblastic leukaemia can result in production of a novel aberrant c-abl protein that is distinct from the bcr-abl protein found in Ph-positive chronic myelogenous leukaemia. Our observations suggest that alternative mechanisms of activation of c-abl exist, and may be important in the development of human acute lymphoid rather than chronic myeloid malignancies.
Electrophoresis, Agar Gel↗
Distribution and effect of some polychlorinated biphenyls in the hemopoietic tissues.
Distribution of 14C-labeled 2,4',5-trichlorobiphenyl 2,2',4,4',5,5'-hexachlorobiphenyl, and 2,2',3,3',4,4',5,6'-octachlorobiphenyl was studied in the hematopoietic tissues of squirrel monkey and mice (C67 Bl) using whole-body autoradiography. An accumulation of radioactivity was seen in the bone marrow of monkey 24 h and 48 h after iv injection of hexachlorobiphenyl and trichlorobiphenyl, respectively. High concentration of radioactivity was also observed in the bone marrow of normal mice injected iv with octachlorobiphenyl. A combination of whole-body autoradiography and spleen-colony assay in supralethally irradiated mice implanted with syngeneic bone-marrow cells indicated the major part of radioactivity to be localized outside the bone-marrow hemic compartment, probably in the fat. No effect of hexachlorobiphenyl but a significant inhibition with octachlorobiphenyl (10(-5) M) and especially trichlorobiphenyl (10(-5) M) was seen on the formation of granulocytic colonies from mouse progenitor cells in vitro.
Animals↗
Light and electron microscopy of varicose vessels and telangiomas in the nasal mucosa of habitual nosebleeders.
Biopsy specimens of abnormal vessels in the nasal mucosa of 42 habitual nosebleeders (22 with telangiomas, 20 with varicose vessels) were examined with light and electron microscopy. There were no specific morphologic features that distinguished the wall structure of solitary varicose vessels from that of telangiomatous lesions consisting of multiple vessel branches. Thus, in both categories of vascular malformations a disproportionately thin and simple wall lined the large lumina. Mostly, the endothelium was the only component in the wall. The endothelium could consist of extremely thin, seemingly degenerating, cells that at some points even failed to form a continuous tunic. At other areas of the same vessel circumference patches of thick, organelle-rich, 'active' endothelial cells could be seen and endothelial cells with intermediate structural characteristics were also found. It is suggested that these endothelial cell appearances represent different stages of cellular proliferation, maturation, and ageing, i.e. turnover. The periendothelial lamina was occasionally multilayered. The large, thin-walled abnormal vessels were covered with scarce connective tissue and a rather thin epithelium. For simple mechanical reasons it is obvious that bleeding, i.e. vessel wall rupture, is easily elicited in these vascular channels and that control of hemorrhage is defect due to the absence of a true muscular media. The findings give rise to interesting questions as to the initiation and control of the abnormal angiogenic response(s) in the nasal mucosa manifested clinically as recurrent epistaxis.
Capillaries↗
Changes in the nasal mucosa of habitual nose-bleeders.
121 habitual nose-bleeders were investigated. In all but one, local changes were found in the nasal mucosa. Abnormal vessels (varicose vessels, telangioma, or a network of small vessels) were found in 102 (84%), and 18 (15%) had mucosal atrophy (rhinitis anterior sicca or septal perforation) without abnormal vessels. The occurrence of abnormal vessels was significantly increased when the bleeders were compared with subjects in a control group. Mucosal atrophy was also significantly more common in the habitual nose-bleeders but only in association with abnormal vessels. Varicose vessels were the most frequent abnormality in both the habitual nose-bleeders and the control group. Telangiomas were only present in the habitual nose-bleeders. Heredity seems to be important in explaining the occurrence of varicose vessels as well as telangiomas in habitual nose-bleeders.
Adolescent↗