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Biomedical subjects

A Georgii

Publications and source records attributed to A Georgii.

At least 145 records · Page 8Linked to original sources
PubMed1984

Malignant (acute) myelosclerosis--a clinical and pathological study in 6 patients.

Clinical and morphological findings are described in 6 patients with malignant (acute) myelosclerosis/fibrosis (MMS). Haematological data are characterized by severe anaemia and thrombocytopenia, frequently accompanied by a leucopenia with an increase in myeloblasts and promyelocytes in the peripheral blood count. There is an absence of, or a minimal hepatosplenomegaly and the survival times after onset of clinical symptoms to death range from 4-12 months. The histopathology of the bone marrow shows a conspicuous proliferation of blasts (myeloblasts, promyelocytes and megakaryoblasts) in a variable amount, besides a fibrosclerosis consisting of reticulin and collagen fibrils. A comparison of MMS with ordinary myelofibrosis/osteomyelosclerosis (MF/OMS) of a chronic course implicates two important facts: (a) evolution of fibrosclerosis takes a considerable period of time for manifestation, which ranges between 20-30 months; (b) the histopathology of MMS is identical with those features observable in the rare event of a terminal stage, i.e. blastic transformation of chronic MF/OMS. Consequently MMS should be designated as an accelerated variant of MF/OMS with a rather early occurrence of a blastic crisis. The insidious onset with the dominant clinical finding of anaemia is probably responsible for the relatively late appearance of symptoms, while the progressive course prevents an overt myeloid metaplasia with a massive hepatosplenomegaly.

Acute Disease↗
PubMed1984

Megakaryopoiesis in chronic myeloproliferative diseases. A morphometric evaluation with special emphasis on primary thrombocythemia.

Morphometry was employed on different entities of chronic myeloproliferative diseases (CMPD) and reactive lesions in addition to normal control specimens. The entities studied included: (1) inflammatory reactions of the bone marrow (so-called myelitis in chronic rheumatoid arthritis), (2) chronic granulocytic leukemia (CGL), (3) agnogenic myeloid metaplasia in an early hypercellular stage (so-called chronic megakaryocytic-granulocytic myelosis, CMGM), (4) agnogenic myeloid metaplasia in an advanced fibrosclerotic stage or osteomyelofibrosis/sclerosis (MF/OMS), (5) polycythemia vera (P. vera), (6) reactive thrombocytosis (TH, as a sequel of miscellaneous conditions) and (7) primary (idiopathic, essential) thrombocythemia (PTH). Evaluation was done on plastic-embedded semithin sections with a constant thickness of 3 micron in approximately 20 cases of each group of CMPD. The following parameters were determined: (1) density distributions of the megakaryocyte and non-megakaryocyte compartments, (2) arrangement of megakaryopoiesis in the bone marrow space (i.e., inhomogeneity or clustering) and (3) the fine structure of megakaryocytes in PTH, with a quantitative analysis of the nuclear morphology by circular deviation and contour factors. The megakaryocyte morphology was closely related to a facultative or obligatory increase of the platelet count in these various entities of CMPD and was separable into two major categories: (1) controls, CGL and myelitis versus (2) CMGM, MF/OMS, P. vera, TH and PTH. These two categories were distinguishable by the prominence of megakaryopoiesis in the bone marrow as well as the elevated platelet counts in the periphery. Moreover, in comparison with CMGM and MF/OMS, PTH was characterized by an apparently normal maturation and a conspicuous polyploidization of megakaryocytes according to the nuclear morphology, which was similar to that of P. vera. Our results suggest that PTH presents a monolinear growth of the megakaryopoiesis in the same way as CGL exhibits a monolinear proliferation of the neutrophilic granulopoiesis. This is in contrast to the mixed cellularity of both the megakaryocyte and granulocyte lineage in CMGM and MF/OMS.

Biopsy↗
PubMed1983

Conversion of an IGM secreting immunocytoma in a high grade malignant lymphoma of immunoblastic type.

A case involving a 67 year old man with an immunocytoma initially presenting as Waldenström's macroglobulinemia which transformed into a high grade malignant lymphoma of immunoblastic type after treatment with cyclophosphamide and corticosteroids over 5 months is presented. IgM (kappa) present in the serum in the phase of immunocytoma was demonstrated also on the less differentiated cells of the high grade lymphoma. The permanent production of the same immunoglobulin molecule suggests that both morphologically different malignancies derived from one B cell clone.

Aged↗
PubMed1983

Determination of growth kinetics in a renal sarcoma of the rat by double labeling with 14C- and 3H-thymidine.

An in vitro double-labeling technique for determination of kinetic growth parameters was tested; 13 renal sarcomas of rats were incubated after excision under standardized conditions with 14C- and 3H-thymidine successively. Another ten tumors were evaluated after in vivo double injection of 14C and 3H-thymidine into sarcoma-bearing animals. In both groups histoautoradiography was performed using a simple stripping-film method. Results including labeling indices, mitotic indices, length of DNA-synthesis phase and cell-production rate obtained by both methods were in excellent agreement. All values fitted those determined in earlier experiments using a continuous labeling and a fraction-labeled-mitoses method in vivo. Theoretical considerations on the calculation of kinetic parameters by double labeling have been added. The experimental results found in this study represent a base for evaluation of biopsies from human tumors.

Animals↗
PubMed1983

Density distribution and size of megakaryocytes in inflammatory reactions of the bone marrow (myelitis) and chronic myeloproliferative diseases.

Morphometric evaluation was performed on semi-thin sections of core biopsies of the bone marrow and included 20 cases of each group of diseases besides control specimens. (i) Hyperergic myelitis of rheumatic origin. (ii) Chronic granulocytic leukaemia (CGL). (iii) Polycythaemia vera (P. vera). (iv) Chronic megakaryocytic-granulocytic myelosis (CMGM). (v) Myelofibrosis or osteomyelosclerosis (MF/OMS). The following classification of megakaryopoiesis was applied: normal megakaryocytes; giant forms; microforms; intussusceptions; cytoplasmic fragments; naked nuclei. The density distribution shows an increase of megakaryocyte number in those 5 different marrow disorders, ranging from about 13/mm2 in the normal sample up to 65 cells/mm2 in MF/OMS. Microforms are most frequently encountered in CGL, whereas giant megakaryocytes, intussusceptions and many cytoplasmic fragments characterize P. vera, CMGM and MF/OMS. Our measurements suggests 3 distinct categories of bone marrow lesions with corresponding alterations of the megakaryopoiesis: (i) myelitis and CGL; (ii) P. vera; (iii) CMGM and MF/OMS.

Bone Marrow↗
PubMed1982

Abnormalities of megakaryocytes in myelitis and chronic myeloproliferative diseases.

A planimetric study of megakaryopoiesis in various chronic myeloproliferative diseases (CMPD) was performed and the results compared with those from controls and myelitis of rheumatic origin. Morphometric measurements included at least 200 megakaryocytes in each case observed in Giemsa-stained semithin sections of resin-embedded core biopsies. Twenty specimens were evaluated from the controls and inflammatory disorders and from each of the following CMPD: 1, chronic granulocytic leukaemia (CGL); 2, polycythaemia vera (P. vera); 3, chronic megakaryocytic-granulocytic myelosis without or with minimal increase in reticulin fibre content (CMGM); 4, myelofibrosis or osteomyelosclerosis (MF/OMS). Megakaryocytes were classified as follows: 1, normal megakaryocytes at all stages of maturation; 2, giant forms; 3, microforms; 4, intussusceptions; 5, a-nuclear cytoplasmic fragments; 6, naked nuclei or necrotic forms. The results of this study demonstrate obvious abnormalities of megakaryopoiesis in addition to the increase in absolute numbers of megakaryocytes per marrow area and their different sizes as reported earlier (Thiele et al. 1982). Aberrations are particularly conspicuous when pure granulocytic proliferation or neoplasia of CGL is compared with the so-called mixed cellularity of megakaryocytes and granulocytes in CMGM including MF/OMS. Abnormalities of the giant forms of megakaryocytes are especially evident and comprise irregular cellular and nuclear perimeters (as calculated by a modified shape factor) in the two latter entities (CMGM-MF/OMS). This remarkable feature is associated with a disorganization of nuclear development and/or a disproportionate nuclear-cytoplasmic ratio which has never been observed in CGL previously. In combination with this striking cellular anomaly, which is compatible with an extreme amoeboid shape of giant forms in CMGM and MF, intussuceptions and a-nuclear cytoplasmic fragments are frequently encountered. The final stage of megakaryopoiesis, i.e. naked nuclei, are increased in number in all CMPD, probably because of enhanced proliferation and platelet shedding. Naked nuclei are often small in CGL (as remnants of the frequent micromegakaryocytes) and large in P. vera and CMGM/MF (depending on the high incidence of giant megakaryocytes in these latter disorders).

Bone Marrow↗
PubMed1981

Oncogenic activity of the BK type of human papova virus in newborn Wistar rats.

The oncogenic potential of the human papova virus BK (= BKV) has been examined in newborn Wistar rats. 12 of 37 animals inoculated with BKV s.c. and 7 of 40 animals inoculated with BKV i.c. developed tumors of various histological types. The latency periods ranged from 6 to 18 months. The BKV etiology of tumors was supported by detection of BKV T antigen in cells of established tumor lines by means of indirect immunofluorescence. No tumors appeared in animals given injections of saline instead of virus. BKV T antibodies were detected in sera of 100 per cent of animals bearing tumors but no in sera of control animals. Only 3 of 77 BKV infected and none of the control animals developed spontaneous tumors (adenomas).

Animals↗
PubMed1980

Chronic megakaryocytic granulocytic myelosis-CMGM. A subtype of chronic myeloid leukemia.

In 1,083 core biopsies of the bone marrow with myeloproliferative diseases 454 cases or 42% were found to have neoplastic megakaryopoiesis. Neoplasia of megakaryocytes was assumed from the conspicuous cytological atypicality revealed by light microscopy, extending and confirming earlier ultrastructural findings. Histopathology of the bone marrow in these patients was described as chronic megakaryocytic-granulocytic myelosis - CMGM - since neutrophilic granulopoiesis is also apparently neoplastic and both cell lineages showed a complete differentiation to mature forms. CMGM should be separated from the chronic granulocytic leukemia - CGL - which consists of only a single line proliferation. The incidence of CGL in our total of 1,083 patients was 25%. Both entities are included in chronic myeloid leukemia - CML - because of the demonstration of the Philadelphia chromosome in the hematopoietic cells of these two groups of patients. Primary or idiopathic thrombocythemia has to be differentiated from CMGM since there is no evidence for malignancy of the granulocytic series.

Bone Marrow↗