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Biomedical subjects

H Felix

Publications and source records attributed to H Felix.

At least 73 records · Page 4Linked to original sources
PubMed1980

[Histoplasmosis: clinical, biological, and therapeutic aspects in ten cases (author's transl)].

The authors present 10 cases of histoplasmosis, 3 due to H. capsulatum, and 7 to H. duboisii. The presenting signs were stomatological or laryngeal with H. capsulatum, and ganglionic, cutaneous, or skeletal with H. duboisii. Diagnosis was confirmed by the discovery of histoplasms in the lesions: 7 times the examination of a needle biopsy sample was positive; in 8 cases out of 10, culture on Sabouraud's medium was positive; in 3 cases out of 4 the inoculated hamster showed the presence of a histoplasmosis. Histological examination of lesions biopsies demonstrated histoplasms in the 9 cases studied. The intradermal reaction to histogical examination of lesion biopsies demonstrated histoplasms in the 9 cases studied. The intradermal reaction to histoplasmin, positive in only 1 out of 7 cases, and serological tests which showed precipitating antibodies in only 4 cases out of 10, are of very little diagnostic value. All patients were treated with amphotericin B, sometimes associated with clotrimazole (3 cases), miconazole (1 case), and rifampicin (2 cases). Two relapses occurred, one, after too soon an interruption of treatment relapsed two months later, and the other followed 18 months after a total dose of 4,200 mg of amphotericin. Surgical treatment of active subcutaneous ganglionic and bony foci may be necessary, and was employed in three cases, with a favourable result in a case of severe disseminated histoplasmosis.

Adolescent↗
PubMed1979

Dynamic morphology applied to human and animal leukemia cells.

Dynamic morphology, which describes the shape and surface architecture of fixed cells in terms related to their behavior in the living state, is based on the concurrent use of two methods: scanning electron microscopy and microcinematography. This combination has both advantages and disadvantages. In this study on leukemic cells, we were able to draw the following conclusions about the usefulness of dynamic morphology. It confirms that white blood cells do not flatten on a glass substrate; they stay spherical and are either round or polarized. Round cells of similar size, whatever their origin, cannot be classified by dynamic morphology. Polarized cells can be classified as blasts, promyelocytes, myelocytes, granulocytes and lymphocytes, although polarized blast cells of different origins cannot be differentiated. Dynamic morphology cannot classify the same cell type as benign or malignant.

Animals↗
PubMed1978

Intermediate-sized filaments in leukemia cells.

Electron microscopic studies on human acute leukemias have shown that leukemic populations contain spherical and polarized cells in various proportions. As recorded by time-lapse cinematography, the two cell configurations represent different functional states: resting cells are completely spherical, locomotive cells are polarized with a conspicuous extension posteriorly. In 9 out of 12 cases of acute myeloid leukemia the two cell configurations were found to coincide with a different pattern of intermediate-sized filaments (ISF). Most spherical myeloblasts possessed large bundles of ISF (a minority had small bundles), whereas polarized myeloblasts showed small groups or single filaments. A similar correlation between cell shape and arrangement of ISF was observed in a transplantable undifferentiated rat leukemia. Two concepts can be distinguished with regard to the role of fibrillar structures in leukemic myeloblasts: thick bundles of ISF either represent a pathological state or have a functional significance. A tentative interpretation of our own results provides some arguments in favor of a disaggregation-reaggregation cycle of thick ISF bundles, whereas a pathological ("end stage") nature of these structures appears less likely.

Acute Disease↗
PubMed1977

Motility of L 5222 rat leukemia cells in the flattened state. Evidence against emperipolesis.

Emperipolesis is the term for the assumed penetration of living cells into other living cells. As reported earlier, L 5222 rat leukemia cells, migrating in vitro, change from a spherical to a spread configuration when they meet flat cells, and continue to move in this shape within the contours of the target cells. Whether or not this close cellular association corresponded to emperipolesis could not be determined with phase and interference contrast cinemicrography alone. In combination with transmission electron microscopy, it could be demonstrated that the compartment, in which the spread leukemia cells move, is not the cytoplasm of the target cells, but the narrow space created by the target cells and the underlying glass surface. Thus, emperipolesis could be ruled out for L 5222 leukemia cells. On this basis the reported observations on emperipolesis are reviewed, and a critical attitude regarding the occurrence of emperiopolesis in general is advocated.

Animals↗
PubMed1977

The role of cellular locomotion in leukemic infiltration. An organ culture study on penetration of L 5222 rat leukemia cells into the chick embryo mesonephros.

The significance of cellular locomotion for leukemic infiltration was investigated using L 5222 rat leukemia cells. Previous cinemicrographic studies have shown that these cells are able to locomote only after formation of a uropod-like posterior extension. This characteristic locomotive configuration of L 5222 cells is easily recognizable in scanning electron micrographs and appropriate sections. Leukemia cells were inoculated on slices of chick embryo mesonephros incubated for 24h; at this time the fragments are completely encapsulated. Leukemic infiltration is found to begin within the first 2 h and to increase gradually up to the end of the observation period at 72 h. Spread of leukemia cells occurs mainly in the intertubular spaces; the tubular epithelium is only rarely affected. In all stages of infiltration, L5222 cells with the characteristic locomotive configuration are frequently recorded. Besides this strong although indirect indication for the significance of locomotion, further evidence was provided by experiments performed at 25 degrees C and 18 degrees C. In accordance with the previous cinemicrographic finding that at these temperatures L 5222 cells are unable to produce their posterior extension, no leukemic infiltration mesonephros fragments is recognizable at subnormal temperatures.

Animals↗
PubMed1977

Synthesis of vaccinia viral antigens in HeLa cells in the presence of isatin beta-thiosemicarbazone.

Vaccinia virus antigens, in HeLa cells treated with the antipox virus drug isatin beta-thiosemicarbazone (IBT), were analyzed by immunoprecipitation, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The total radioactivity in the immunoprecipitate was decreased to almost 50% in the presence of the drug as compared to its absence. An inhibition also occurred with an IBT-dependent mutant (IBT(D)) when growing in the absence of IBT. However, similar levels of radioactivity were observed in the immunoprecipitates from an IBT-resistant mutant (IBT(R)) grown in either the absence or presence of the drug. When the antigens within the immunoprecipitates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it was shown that the inhibition observed in the wild-type-infected cells in the presence of IBT and in the IBT(D)-infected cells in the absence of the drug, was quantitative, affecting the amounts of the different polypeptides more or less equally.

Animals↗
PubMed1976

Motility of l5222 rat leukemia cells.

The locomotive behavior of cells of the transplantable rat leukemia L5222 was studied by means of microcinematography. It was found that these cells exhibit a homogeneous pattern of movement resembling that of normal lymphoblasts and stimulated lymphocytes. This is in contrast to cytochemical and ultrastructural evidence according to which the cells are completely undifferentiated. Another phenomenon, recorded by timelapse, is the ability of the cells to move in a spherical and in a flattened state. Treatment with cytochalasin B in a concentration of 30mug/ml leads to loss of locomotion. Incubation with colchicine, 40mug/ml, results in a greatly reduced locomotion, while the on-spot motility is not impaired. The suitability of this model for investigations on the role of locomotion in penetration and tumor cell dissemination is emphasized.

Animals↗
PubMed1975

[Recrudescence of imported malaria (apropos of 30 recent cases)].

30 cases of imported malaria were diagnosed in the Laboratoire Central de Parasitologie of the Pitié-Salpêtrière C.H.U. in less than five months. The circumstances of appearance and the conditions of the patients' stay, the difficulties of the clinical diagnosis of the primary invasion, the gravity of P. falciparum attacks and the therapeutic schedules are presented. The accent is placed on the deficiencies of correctly prescribed anti-malaria chemotherapy and on the importance of information and sensitization of travellers.

Adolescent↗
PubMed1975

[Acute amebic abscess of the liver followed by colonic ulcers. Report of 2 cases].

Two unusual cases of ruptured acute amebic liver abcess are presented one with inferior vena caval compression. Surgical drainage was followed by the development of colonic complications (haemorrhage and perforation) although the patients were under specific therapy. After a new surgical operation both cases were cured. The relation with amebiasis is discussed. The possibility of such an association must always be kept in mind. The value of immunofluorescence test in the diagnosis is emphasised.

Adult↗