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Biomedical subjects

J Laczkó

Publications and source records attributed to J Laczkó.

At least 19 recordsLinked to original sources
PubMed1991

Phagocytosis of autologous platelets by human neutrophil granulocytes.

The phenomenon that the autologous human platelets can be phagocytosed in vitro by neutrophils and monocytes of healthy human donors (being free of antiplatelet autoantibodies) was demonstrated earlier. In this study we have confirmed electron microscopically the phenomenon of phagocytosis. Besides, using flow cytometric analysis, we have shown that a possible way for the bridge-formation between the washed platelets and neutrophils can be the linkage via IgG + C3b complexes bound to the Fc receptors of platelets. This mechanism supposedly may play a role also in the clearance of platelets by peripheral phagocytes in vivo.

Blood Platelets↗
PubMed1990

Detection of HIV in the peripheral mononuclear cells of asymptomatic haemophiliacs in Hungary.

The presence of virus in peripheral blood mononuclear cells of asymptomatic antibody positive haemophiliacs was detected by assaying for reverse transcriptase and confirmed by electron microscopy and immunofluorescence. HIV has been detected in 5 out of 7 individuals. In order to investigate strain variation, supernatant fluids of cultures were added to H9 and MT-4 cells. Virus was recovered in MT-4 cells in 3 cases, whereas the H9 cells only supported the replication of 2 strains. Viruses isolated from asymptomatic haemophiliacs have a narrower range of infectivity than HTLV-IIIB.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Wiskott-Aldrich syndrome in a hetrozygous woman].

The authors report a case of a 20-year old woman, with all the characteristics of the Wiskott-Aldrich-syndrome. The main signs of the disease were recurrent infections, eczema, thrombocytopenia and mild mucosal bleeding. The size of platelets was reduced. Storage pool disease was based on the abnormal platelet aggregation and the lack of dense bodies shown by electronmicroscopic examination. The disturbances of the lymphocytes, neutrophils and monocytes, which resulted in immunodeficiency, could be proven by the immunological tests. This X-linked recessive disorder appeared with typical signs in a heterozygous carrier woman. According to our knowledge, no similar case has been reported before.

Adult↗
PubMed1985

Vesicle release from erythrocytes during storage and failure of rejuvenation to restore cell morphology.

During storage, discocyte-echinocyte transformation of erythrocytes occurs progressively and microvesicles release from the spicules in the form of membrane-encapsulated red cell fragments. After rejuvenation part of the membrane-deficient cells, mainly spheroechinocytes, transform into spherostomatocytes because of their inability of restoring the surface area to volume ratios of normal discocytes. The proportion of spherostomatocytes formed on rejuvenation increases with storage time. Numerical indices for characterizing the "level of reversion" and the "quality of reversion" were developed. Osmotic fragility curves and light scattering histograms also reflected a partially irreversible increase of inhomogeneity of stored cell populations.

2,3-Diphosphoglycerate↗
PubMed1979

Functional heterogeneity of macrophages.

The antibody-binding activities of rabbit peritoneal macrophages separated on discontinuous gradients of Ficoll were investigated. The antibody was rabbit anti-ovalbumin IgG labelled with 125I. Of the five fractions obtained, one macrophage fraction was found to bind substantially more antibody than the others. These macrophages possessed more Fc receptor sites than the others and the number of Fc receptors (n) and the association constant (K) of these cells was calculated. By electron microscopy, the phagocytic activity of the subpopulation with most Fc receptors was less than that of the others.

Animals↗
PubMed1975

Effect of triiodothyronine treatment, thyroparathyroidectomy and mercaptoiminazole treatment on enchondral bone growth. Changes in the histological structure of the growth organ.

Histological changes caused by triiodothyronine (T3) and mercaptoiminazole treatment as well as by thyroidectomy have been studied in the proximal growth organ of the tibia of growing rats. On triiodothyronine treatment morphometric examinations revealed an increased proliferation and resorption of cartilage associated with a transitory acceleration of linear bone growth. Administration of mercaptoiminazole and thyroidectomy inhibited cartilage proliferation and resorption resulting in a slowing down of bone growth.

Animals↗
PubMed1975

The effect of glucose-1 phosphate calcium on the epiphyseal cartilage of the rat.

Electron microscopic investigations were carried out on the proximal tibial epiphyseal cartilage of albino rats treated with 2 mg G-1-P-Ca daily for one and three weeks. The treatment--enhanced the secretory activity of the upper cells of the zone of maturing cartilage with a consequential enlargement of the Golgi region, depletion of secretory products, and an increase in the number of microtubuli. --In addition, the treatment increased the number of matrix vesicles in the extracellular space showing incipient calcification. This findings confirm the earlier light micriscopic observation of the calcification stimulating effect of G-1-P-Ca.

Animals↗
PubMed1975

Effect of triiodothyronine (T3) thyroparathyroidectomy and mercaptoimidazole treatment on enchondral bone growth. II. Growth dynamics in the proximal growth organ of the tibia in young rats.

The 24 hour growth rate of the tibial proximal growth organ was investigated in triiodothyronine or mercaptoimidazole-treated, and in thyroidectomized male rats. Longitudinal growth of the tibia of the same period was also studied. After one week treatment, the 24 hour rate of growth in the triiodothyronine-treated rats was retarded as compared with the controls, whereas at the end of the 3rd and 5th weeks the growth rate of the treated animals exceeded that of the controls. The tibia was somewhat longer in the treated rats than in the untreated controls, though the difference was not significant. The growth rate in the growth organ of mercaptoimidazole-treated and thyroidectomized animals was generally higher than that measured in the controls. The length of the tibia was less than in the controls, but the difference was not significant. The phenomenon is attributed to the altered hormonal conditions.

Animals↗