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Biomedical subjects

A Georgii

Publications and source records attributed to A Georgii.

At least 163 records · Page 9Linked to original sources
PubMed1980

Ultrastructure of blastic crisis in osteomyelofibrosis. A report of 2 cases with some unusual features.

The clinical and morphological findings are presented in two patients suffering from myelofibrosis and osteomyelosclerosis which terminated in an acute blastic crisis. Clinical follow-up data and light microscopy of the bone marrow however, revealed a chronic megakaryocytic-granulocytic myelosis (CMGM) with progression into myelofibrosis during the course of disease. In one patient the blastic transformation involved predominantly basophils, and in the other, neutrophils, with an accompanying abnormal proliferation of megakaryocytes in both cases. Electron microscopy of this cell population demonstrated remarkable atypicalities of the neutrophilic, basophilic and megakaryocytic cell lines. These abnormalities consisted of a nuclear-cytoplasmic asynchrony and a partial arrest of maturation, sometimes resulting in bizarre cell forms. Our investigations support the hypothesis of a mixed cellularity type of myelosis with a gradual and insiduous progression into osteomyelofibrosis/-sclerosis and a potential blastic crisis. In the evolution of blastic crisis all cell lines may be transformed, but with predominance of one population - basophils and neutrophils in our two cases - in addition to atypicalities of megakaryocytes.

Acute Disease↗
PubMed1980

Angioimmunoblastic lymphadenopathy. Fine structure of the lymph nodes by correction of light and electron microscopical findings.

Angioimmunoblastic lymphadenopathy was studied prospectively in 5 patients by correlation of light and electron microscopy of biopsy material obtained from lymph nodes, prior to any substantial therapy. The fine structure of this lymphoproliferative disease revealed various patterns of cellular composition: there was a predominance of lymphocytes, immunoblasts, epithelioid or plasmacytoid cells or mixed cellularity in the lymph nodes. The conspicuous vascular changes consisted or arborization of postcapillary venules, a thickening of the basement membranes and swelling of the endothelial cells. The remarkable eosinophilic or acidophilic debris-like interstitial and pericapillar deposits showed filamentous finely dispersed material containing wide-spacing collagen fibers intermingled with normal collagen, but no fragments of disintegrated cells. Two of these 5 patients developed malignant lymphomas of the Hodgkin-type after 13 months, and of the Non-Hodgkin-type after 7 months. At the time of first biopsy, however, no characteristic alteration of the fine structure of the lymph nodes disclosed evolution towards malignancy.

Aged↗
PubMed1979

Histopathology of bone marrow in human chronic leukemias.

Among the patients with chronic myeloproliferative diseases including clinical symptoms of chronic myelogenous leukemia--CML--two varying compartments with substantially differing histology of hemopoiesis were found: one with predominating granulopoiesis for which the usual term of chronic granylocytic leukemia--CGL--seems inadequate. The other with proliferation of granylopoiesis and megakaryopoiesis as a neoplasia with a mixed cellularity is observed to be different in its clinical course: there are often a leukemic or subleukemic cell counts, but mostly considerable increased platelets in the peripheral blood; there is a prolonged period of latency, a higher age group, an infrequent occurrence of blastic crisis and a regular outcome into myelofibrosis. This entity of chronic megakaryocytic granulocytic myelosis--CMGM--can be seen very frequently among myeloproliferative diseases. Among a total of 718 core biopsies from the bone marrow the CMGM-patients are up to 29% compared with 21% of the typical one-cell-line disease CGL. The Ph1-chromosome may be presented in the CMGM-entity likewise.

Bone Marrow↗
PubMed1979

Polycythemia vera: electron microscopy of the bone marrow in 10 non-treated patients. A thin section and freeze-fracture study.

Electron microscopy (thin sections and freeze-fracture replicas) was performed on the bone marrow of ten patients with Polycythemia vera prior to any treatment. In addition to a hyperplasia of all three cell lineages and the sinuses, atypias were observed in the maturing erythroblasts. These aberrations of normal development consisted mainly of deep invaginations of the nuclear envelope in proerythroblasts and conspicuous nuclear clefts in erythro- and normoblasts. In comparison with similar changes in dyserythropoietic and aplastic anemia as well as leukemia these alterations are discussed in connection with disturbances of DNA synthesis. Further atypias involved megakaryopoiesis which displayed microforms probably as an evidence for maturation arrest. These ultrastructural abnormalities and their morphological features of a neoplastic proliferation of all three cell lineages in Polycythemia vera are in good agreement with the new concept of a transformation of a pluripotent stem cell with clonal character.

Adult↗
PubMed1979

Chronic myelomonocytic leukemia: light and electron microscopy of the bone marrow.

Clinical data and light and electron microscopic findings are presented in a patient with chromic myelomonocytic leukemia of about 5 years' duration and no need for specific therapy. Cytogenetic studies failed to demonstrate a Philadelphia-chromosome. The leading clinical symptoms were anemia, moderate hepatomegaly, and leukocytosis with monocytes in the peripheral blood count. Light microscopy of bone marrow cores showed hypercellularity of neutrophil granulocytic and monocytic cell lines including some precursor forms. Electron microscopy confirmed the existence of a biphasic myelomonocytic cell proliferation with predominance of mature forms in both lineages; there were no gross cellular abnormalities and no "hiatus leukaemicus". Consupicuous were cells of an undeterminated origin apparently neither belonging to the neutrophil granulocytic nor monocytic series and large histiocytic cells, possibly corresponding to the so-called sea-blue histiocytes of light microscopy. The high degree of maturation of both cell lines in the bone marrow is in accordance with the relatively benign and prolongated course of this rare type of leukemia.

Aged↗
PubMed1979

Early gastric cancer: a morphological study of 144 cases.

Within 144 early gastric cancers (EGC), the ulcerated type was most frequent (54.2%), followed by the superfical (29.9%) and protruded types (16%). 10.4% of EGC originated from adenomatous polyps of gastric mucosa. No positive correlation between hyperplastic polyps and occurrence of EGC could be stated. Antrum and corpus regions were preferred localization of EGC, harboring about 90% of the tumors. Histologic classification according to Laurén (1965) proved to be very reliable, revealing an intestinal type of EGC in 53.1% and a diffuse type in 32.4%. Primary anaplastic tumors seem to be very rare. Intestinal types were predominant in males, especially in the elderly patient. In about 50% the tumor was still limited to the mucosa with the exception of Type I, since those tumors originating from polyp infiltrated submucosa above and those without evidence of a preceding polyp, below average. Regional metastases were found in 4.2% with one primary tumor still limited to the mucosa. In the pure intestinal type of EGC metastases did not occur at all. Multicentricity of EGC was, with 2.8%, remarkably low, compared with the findings of others. Excluding malignancies, the only other noteworthy concurrent lesions were ulcer scars or chronic ulcers with 6.9% and B II resection for benign disease with 2.8%.

Adenocarcinoma↗
PubMed1978

Evaluation of continuous labelling data by a practical mathematical method with application to a virus-induced sarcoma of the rat.

A simple mathematical function is established which renders the increase of the labelling index during continuous labelling of an exponentially growing tumor. By known values of proliferative fraction, mean cell cycle time and tumor doubling time, the mode and extent of cell loss is determined. Three models for different modes of cell loss are introduced: Model A for cell loss equally affecting proliferative and resting cells; Model B for cell loss predominantly affecting one of the two cell compartments; Model C for cell loss during mitosis. The range of validity of the model function is specified. Experimental data of a Polyoma virus-induced renal sarcoma of the rat provide an example of applicability of the theoretical model.

Animals↗
PubMed1978

Further investigations on the antioncogenic activity of A/PR8/34 (HON1)- influenza virus on polyoma virus induced tumors in newborn Wistar rats.

The oncogenic activity of polyoma virus in newborn Wistar rats can be significantly reduced by simultaneous vaccination with the A/PR8/34 (HON1) strain of influenza virus. The antioncogenic activity (AOA) of influenza virus suspensions was neutralized by the addition of homologous influenza antibodies, indicating that AOA was due to influenza virus and not to any non-viral material possibly present. The AOA of influenza virus was found to decline with storage at 4 degrees C and to depend critically on the relative doses of influenza virus and polyoma virus inoculated per animal. Simultaneous inoculation of animals with influenza and polyoma virus reduced significantly the antibody response to polyoma virus in all experiments, suggesting that influenza virus reduced the multiplication of polyoma virus. By contrast, the antibody response to influenza virus was significantly enhanced by inoculation with polyoma virus in some experiments, only. Influenza virus was found to reduce markedly the adsorption of polyoma virus on rat embryo fibroblast cells, suggesting that AOA could be at least partially due to interference of influenza virus with polyoma virus adsorption on target cells.

Animals↗
PubMed1977

Chronic megakaryocytic-granulocytic myelosis--an electron microscopic study including freeze-fracture. II. Granulocytes, erythrocytes, plasma cells and myeloid stroma.

In 5 patients with chronic megakaryocytic-granulocytic myelosis (CMGM) bone marrow specimens were studied by electron microscopy to investigate possible abnormalities of the granulocytic cell lineage. Thin sections were compared with freeze-fracture replicas to elucidate further aspects of leucocyte cytology. The atypia exhibited in these cells (eosinophils, basophils and neutrophil granulocytes) consisted mostly of a disorganization of granulopoiesis with hyper- and hypogranulation, a pathological increase in the number of nuclear blebs and a maturation asynchrony sometimes leading to Pelger-like cell forms. Moreover, a presumptive stem cell was demonstrated in the erythopoietic and granulocytic cell lines resembling CFU cells. In conclusion, granulopoiesis in CMGM exhibited abnormalities as generally observed in chronic myelogenous leukaemia. When considered with our previous finding of malignancy in megakaryopoiesis, CMGM has to be classified as a myelosis of mixed cellularity.

Bone Marrow↗
PubMed1977

Chronic megakaryocytic-granulocytic myelosis--an electron microscopic study. I. Megakaryocytes and thrombocytes.

The fine structure of the bone marrow in chronic megakaryocytic-granulocytic myelosis (CMGM) was studied in 5 nontreated patients to investigate possible malignant proliferation of megakaryocytes and the role of megakaryopoiesis in fibrillogenesis, terminating in osteomyelofibrosis. In comparison with normal megakaryopoiesis there is an enormous increase of the megakaryocytic cell line and many immature and atypical forms are seen. Most conspicuous are microforms, nuclear-cytoplasmic disorganization and nuclear inclusions. Asynchrony of maturation causes abnormal thrombocytogenesis with premature detachment of platelets resulting in immature and peculiar giant forms of thrombocytes. Besides megakaryocytes appearing superficially normal the maturation anarchy of many cells is so severe that by analogy with observations in other leukaemic cells these abnormalities are thought to be representative of a malignant growth. Moreover, there is a striking accumulation of microfibrils and single collagen fibres around megakaryoblasts. Since these cells contain all those organelles commonly associated with fibre production the initial step for fibrillogenesis may therefore arise from the megakaryoblasts prior to platelet release, or any fibroblast proliferation.

Blood Platelets↗