426
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Baffy G, Varga Z, Fóris G, Leövey A. Disturbed intracellular calcium-related processes of hepatocytes and neutrophils in human alcoholic liver disease. Clin Biochem 1990; 23:241-5. [PMID: 2142639 DOI: 10.1016/0009-9120(90)90692-n] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Isolated human hepatocytes and separated neutrophils of 11 patients with alcoholic liver disease (ALD) were used to study some aspects of cellular calcium-related processes compared to nonalcoholic controls. 45Ca2+ efflux from the cells decreased in ALD and the calmodulin-inhibitor trifluoperazine did not influence it further. The intracellular free calcium concentration [( Ca2+]i) of nonstimulated hepatocytes and neutrophils proved to be higher in ALD with the Quin2/AM loading technique. However, the [Ca2+]i rise in hepatocytes and neutrophils, with stimulation by low density lipoprotein (LDL) and N-formyl-methionyl-leucyl phenylalanine (FMLP), respectively, was diminished in ALD compared to appropriate controls. The slower 45Ca2+ extrusion rate, higher basal [Ca2+]i levels, and the diminished [Ca2+]i elevation of activated hepatocytes and neutrophils, suggest disturbed calcium-related intracellular processes in ALD, in particular, impaired regulation of the plasma membrane Ca2(+)-ATPase.
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427
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Varga Z, Jacob MP, Csongor J, Robert L, Leövey A, Fülöp T. Altered phosphatidylinositol breakdown after K-elastin stimulation in PMNLs of elderly. Mech Ageing Dev 1990; 52:61-70. [PMID: 2156116 DOI: 10.1016/0047-6374(90)90144-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The degradation of elastic fibres during atherosclerotic plaque formation in arterial wall is a well known process. The liberated elastin peptides such as K-elastin possess various biological activities: They are chemotactic for monocytes and fibroblasts, stimulate the oxidative burst and the intracellular free Ca2+ mobilisation through the phosphatidylinositol (PIP2) breakdown in PMNLs. It was found that the PIP2 breakdown induced by K-elastin is a pertussis toxin sensitive process in PMNLs of young subjects. In the case of the elderly, the K-elastin-induced oxidative burst, intracellular free Ca2+ elevation was less than in young, and could not be inhibited by pertussis toxin. Studying the K-elastin-induced inositol phosphate (IP) formation in PMNLs of elderly a disturbed PIP2 breakdown was found. K-elastin stimulated the IP formation at a very low level in PMNLs of elderly. This alteration of the second messenger formation (e.g. IP3 and Ca2+) after KE stimulation, might be the consequence of their originally elevated levels in resting PMNLs of elderly.
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428
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Varga Z, Bressani N, Zaia AM, Bene L, Fülöp T, Leövey A, Fabris N, Damjanovich S, Zaid AM. Cell surface markers, inositol phosphate levels and membrane potential of lymphocytes from young and old human patients. Immunol Lett 1990; 23:275-80. [PMID: 2278550 DOI: 10.1016/0165-2478(90)90072-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is well known that most physiological functions change with aging, including the immune response. Data concerning the aging of lymphocyte subpopulations are conflicting. The antigen density of peripheral blood lymphocytes has been determined by fluorescently tagged OKT-3, OKT-4, OKT-8, OKT-11 and OKM1 monoclonal antibodies in a carefully selected aged (over 87 years) population, and compared to that of young subjects. A substantial difference was found in the percentage distribution of OKT8 and OKM1 subsets. The volume of lymphocytes of the elderly population was significantly less than that of the young. The effect of various monoclonal antibodies on phosphatidylinositol breakdown has also been studied. It was found that only OKT3, acting through the CD3 antigen receptor, was able to induce inositol phosphate formation in both young and elderly, although in the latter population this occurred at a lower level. Because the plasma membrane plays a regulatory role in this process, an important and sensitive functional parameter, the membrane potential, was also monitored and influenced by changing the extracellular K+ concentration. The lymphocytes of the elderly population responded less sensitively to changes in extracellular potassium concentration.
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429
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Szekeres-Bartho J, Reznikoff-Etievant MF, Varga P, Pichon MF, Varga Z, Chaouat G. Lymphocytic progesterone receptors in normal and pathological human pregnancy. J Reprod Immunol 1989; 16:239-47. [PMID: 2614759 DOI: 10.1016/0165-0378(89)90053-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The progesterone receptor-specific monoclonal antibody (MoAb) mPRI was tested for its reactivity towards peripheral blood lymphocytes (PBL) of 49 healthy pregnant women, nine pregnant women with clinical symptoms of threatened preterm delivery, seven women with recurrent spontaneous abortion, ten women in labour and ten women with spontaneous abortion. Lymphocytes of 12 healthy age-matched non-pregnant volunteers were used as controls. Lymphocytes of nine healthy pregnant women at the 1st trimester of pregnancy and those of two non-pregnant donors were tested for the presence of estrogen and progesterone receptors by enzyme immunoassay. PBL of healthy pregnant women contained significantly more positive cells than those of non-pregnant controls. Furthermore, the number of receptor-containing cells increased in parallel with gestational age. In blood samples drawn during labour, as well as in those obtained from women with spontaneous abortion or clinical symptoms of threatened pre-term delivery, the percentage of positively stained lymphocytes was significantly lower than normal pregnancy values. This was also the case in peripheral blood of pregnant women with a history of recurrent spontaneous abortions.
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430
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Varga Z, Jacob MP, Robert L, Fülöp T. Identification and signal transduction mechanism of elastin peptide receptor in human leukocytes. FEBS Lett 1989; 258:5-8. [PMID: 2556298 DOI: 10.1016/0014-5793(89)81602-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The existence of a novel receptor on human polymorphonuclear leukocytes (PMNLs) and monocytes was demonstrated, named soluble elastin peptide receptor. Soluble elastin peptides, like K-elastin, which are liberated from elastin fibres, can be found in the sera, and they possess several biological activities such as chemotaxis. Studying the effects of elastin peptides on leukocytes, it was found that: (i) the elastin peptide stimulates the oxidative burst, the intracellular free Ca2+ elevation through a specific receptor; and (ii) in the signal transduction mechanism of this elastin peptide receptor, the phosphatidylinositol breakdown is involved.
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431
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Falus A, Kramer J, Walcz E, Varga Z, Setalo J, Jobst K, Lakatos T, Merétey K. Unequal expression of complement C4A and C4B genes in rheumatoid synovial cells, human monocytoid and hepatoma-derived cell lines. Immunology 1989; 68:133-6. [PMID: 2553583 PMCID: PMC1385517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
C4A and C4B are closely related homologous complement proteins encoded in the class III region of major histocompatibility complex (MHC). The regulation of their expression is under genetic and hormonal control. In this study we investigated the synovial fluid plasma ratio of C4A and C4B of rheumatoid (RA) and osteoarthritis (OA) patients, and a predominance of the C4B gene expression by the synovial macrophages of RA patients was demonstrated. To clarify the tissue specificity of the expression of C4A and C4B genes, human monocytoid cell line U937 and hepatoma-derived HepG2 cells were studied. The gene expression of C4A and C4B were markedly different in these cells since a relative predominance of C4B mRNA in U937 cells and excess of that of C4A in HepG2 cells were detected. Recombinant interferon-gamma (IFN-gamma) up-regulated the expression of C4A gene in both cells, but had apparently no effect on the C4B gene. Our results demonstrate dissimilar expression patterns for the two human C4 genes, suggesting different tissue specific regulation of human C4A and C4B.
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432
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Sánta S, Varga Z, Antal S. [Experience with the surgical management of rupture of the capsule and ligament of the acromioclavicular joint]. Orv Hetil 1989; 130:1537-41. [PMID: 2671860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Evaluating the surgical results obtained with 74 cases of acromioclavicular dislocation the authors review the problems of diagnostics and surgical treatment of the injury. It is pointed out that the restoration of the functional anatomical condition--and simultaneously the reduction of the number of posttraumatic complaints--may be ensured only with operation in cases of severity grade II and III. However the results of the operative techniques applied in a rather wide range at present do not come up to expectation. The disturbances of healing are due in the majority of the cases to the use of implants unsuitable from biomechanical point of view. The application of appropriately solid acromioclavicular plates means significant progress in this field. The time and way of restoration of the injured capsule and ligament system influences decisively the results. Sutures of the ligament applied within 24 hours after the injury heal well. If the ligaments show strong splitting up or the operation is performed delayed plastic reinforcement or completion is justified in each case owing to the partial resorption. From the viewpoint of the surgical technique the use of the softpart flaps formed from the environment appear to be the most favourable.
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433
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Szekeres-Bartho J, Reznikoff-Etievant M, Varga P, Varga Z, Chaouat G. Progesterone-mediated immunosuppression in pregnancy II. Lymphocytic progesterone receptors in normal and pathologic pregnancies. J Reprod Immunol 1989. [DOI: 10.1016/0165-0378(89)90394-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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434
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Fülöp T, Varga Z, Csongor J, Fóris G, Leövey A. Age related impairment in phosphatidylinositol breakdown of polymorphonuclear granulocytes. FEBS Lett 1989; 245:249-52. [PMID: 2494076 DOI: 10.1016/0014-5793(89)80231-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It is well known that with aging the immune response decreases. Most of the effector functions occur through specific receptors. Thus, we investigated the effects of various stimulants, acting through receptors or directly through the GTP-binding Gi protein, on phosphatidylinositol breakdown in PMNLs of young and elderly subjects and try to modulate it. A marked decrease in inositol phosphate (IP1, IP2, IP3) formation in PMNLs of elderly was found under FMLP stimulation when compared to that of young subjects. Neither GTP gamma S, nor AIF4- could induce an increase of IP3 in PMNLs of elderly comparable to that of young subjects. The results suggest that at least an alteration exists at the GTP-binding Gi protein level, as well as in the mechanism of linkage of the receptor to the G protein.
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435
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Fülöp T, Varga Z, Nagy JT, Fóris G. Studies on opsonized zymozan, FMLP, carbachol, PMA and A23187 stimulated respiratory burst of human PMNLs. BIOCHEMISTRY INTERNATIONAL 1988; 17:419-26. [PMID: 2849440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The O2- production as a marker of the respiratory burst was investigated under various stimulations in polymorphonuclear leukocytes of healthy young and aged subjects. Stimulation of the respiratory burst in the cells of elderly by specific agents (opsonized zymozan, N-formyl-methionyl-leucyl-phenylalanine, carbachol) resulted in a diminished response while it remained unchanged on the effect of non-specific stimulation (A23187, phorbol myristate acetate) comparing to young subjects. To elucidate the postreceptor signal transduction mechanism involved in respiratory burst stimulation various inhibitors were used as follows: neomycin (for phospholipase C enzyme), mepacrine (for phospholipase A2 enzyme) and pertussis toxin (for GTP binding regulatory protein). The results suggest that phospholipase C as well as phospholipase A2 could be involved in the postreceptor signal transduction depending on the stimulus, but the impairment of the pertussis toxin sensitive GTP binding protein with aging might explain the decrease response of the respiratory burst after stimulating the different receptors.
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436
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Varga Z, Kovács EM, Paragh G, Jacob MP, Robert L, Fülöp T. Effect of elastin peptides and N-formyl-methionyl-leucyl phenylalanine on cytosolic free calcium in polymorphonuclear leukocytes of healthy middle-aged and elderly subjects. Clin Biochem 1988; 21:127-30. [PMID: 3390898 DOI: 10.1016/s0009-9120(88)80101-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effect of elastin peptides (kappa-elastin, KE) and N-formyl-methionyl-leucyl-phenylalanine (FMLP) on cytosolic free calcium in polymorphonuclear leukocytes (PMNLs) of healthy middle-aged (35-45 years) and elderly (greater than 60 years) patients with normal and high serum cholesterol level was investigated. The cytosolic free calcium [( Ca2+]i) elevation after stimulation with these compounds was decreased in PMNLs of the aged groups compared to the healthy middle-aged group. The guanine nucleotide binding regulatory Gi protein inhibitor, pertussis toxin (PT) prevented the enhancing effect of KE and FMLP on PMNL free calcium of healthy middle-aged subjects, but could not completely abolish the [Ca2+]i elevation in PMNLs of aged subjects.
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437
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Stipkovits L, Kobulej T, Varga Z, Juhász S. In vitro testing of the anti-mycoplasma effect of some anti-coccidial drugs. Vet Microbiol 1987; 15:65-70. [PMID: 3439016 DOI: 10.1016/0378-1135(87)90130-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The anti-mycoplasma effects of the ionophores (lasalocid sodium, monensin and nigericin) were compared with that of tylosin tartrate and tiamulin in vitro. Forty-four strains representing 14 avian and 10 mammalian Mycoplasma species and serotypes and 5 Acholeplasma species were tested. The ionophores showed average minimal inhibitory concentration (MIC) values between 3.65 and 4.93 micrograms ml-1 for all strains, the MIC values for glucose-fermenting strains were between 2.26 and 3.75 micrograms ml-1, significantly lower than for arginine-hydrolysing strains (9.27-13.12 micrograms ml-1). These values were significantly higher than those obtained with tylosin tartrate (0.45 micrograms ml-1) or tiamulin (0.13 micrograms ml-1). The ionophores were more efficacious against acholeplasmas (0.06-0.25 micrograms ml-1) than against mycoplasmas.
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438
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Fóris G, Medgyesi GA, Nagy JT, Varga Z. Concentration-dependent effect of met-enkephalin on human polymorphonuclear leukocytes. Ann N Y Acad Sci 1987; 496:151-7. [PMID: 3474966 DOI: 10.1111/j.1749-6632.1987.tb35758.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Met-enkephalin in 10(-9)-10(-7)M concentrations exerts an ADCC-stimulating effect on human PMNLs through naloxone-sensitive opiate receptors, elevating the cytoplasmic free Ca2+ and cGMP levels. In higher, 10(-6)-10(-5)M concentrations ME has a cAMP-elevating effect and a rapid 45Ca2+ influx was observed. This latter effect of ME, which is also associated with the suppression of ADCC activity, was abolished by the enkephalinase inhibitor, puromycin. A strong relationship is suggested between the suppressing effect of metenkephalin, enkaphalinase and the protein kinase C system.
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439
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Glavits R, Ratz F, Varga Z, Stipkovits L, Molnar E. Histogenesis of the myeloid system in geese. Avian Pathol 1987; 16:469-78. [PMID: 18766635 DOI: 10.1080/03079458708436396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Using light- and electron-microscopy the location in organs and the time-course of appearance of cells of the myeloid system was studied in goose embryos and goslings. Large numbers of cell forms representing different stages of granulocytopoiesis were found between 15 and 28 days of incubation in the mesenchyma of the kidney and in the reticular tissue of the spleen, but not in the liver and other organs. Thus, before the haemocytopoietic activity of the bone marrow, an activity typical of adult birds, develops, in geese embryonic extra-medullary granulocytopoiesis is characterised by a renal-lienal stage.
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440
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Fülöp T, Jacob MP, Varga Z, Foris G, Leövey A, Robert L. Effect of elastin peptides on human monocytes: Ca2+ mobilization, stimulation of respiratory burst and enzyme secretion. Biochem Biophys Res Commun 1986; 141:92-8. [PMID: 3643024 DOI: 10.1016/s0006-291x(86)80339-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The effect of elastin peptides (Kappa-elastin) was investigated on human monocytes. The data presented here indicate that elastin peptides increase the intracellular Ca2+ level measured by Quin 2 fluorescence and mediate the release of beta glucuronidase and elastase. The O2 consumption and H2O2 release were stimulated in a dose-dependent manner. The early rise of cAMP was followed by a return to the original level at 30 min and by a concomitant increase of cGMP level. The action of elastin peptides on intracellular calcium level and cGMP levels may well be related to its previously demonstrated chemotactic activity. These activities may well play a role in the modifications of the extracellular matrix following elastin degradation as observed in atherosclerosis, emphysema and aging.
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441
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Varga Z, Stipkovits L, Dobos-Kovács M, Sántha M. Investigation of goose mycoplasmas. ARCHIV FUR EXPERIMENTELLE VETERINARMEDIZIN 1986; 40:105-8. [PMID: 3963996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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442
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Stipkovits L, Varga Z, Laber G, Böckmann J. A comparison of the effect of tiamulin hydrogen fumarate and tylosin tartrate on mycoplasmas of ruminants and some animal ureaplasmas. Vet Microbiol 1984; 9:147-53. [PMID: 6730305 DOI: 10.1016/0378-1135(84)90030-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The in vitro efficacy of tiamulin was compared to that of tylosin against 7 bovine, 7 ovine and 3 caprine mycoplasma strains isolated from various organs and belonging to different species, as well as 7 ureaplasma strains cultured from cattle, sheep, swine, chickens and turkeys. The minimal mycoplasmacidal concentrations of tiamulin varied between 0.01 and 10.0 micrograms ml-1, while tylosin proved to be active in concentrations of 0.5 and 100.0 micrograms ml-1. Five of 17 mycoplasma strains showed identical sensitivities to both antibiotics while all other strains, including the ureaplasmas, were sensitive to tiamulin at concentrations 5-5000-times lower than tylosin.
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443
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Molnár M, Varga Z, Joó Z, Varsányi J, Pethö I. [Pure high-grade deep-frozen raw human milk]. Orv Hetil 1983; 124:1637-40. [PMID: 6888915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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444
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Horváth G, Stipkovits L, Varga Z, Zöldág L, Mészáros J. Infection of cows by Mycoplasma bovis. ARCHIV FUR EXPERIMENTELLE VETERINARMEDIZIN 1983; 37:401-403. [PMID: 6615134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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445
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Stipkovits L, Mészáros J, Pázmany B, Varga Z. Isolation of mycoplasmas from bull semen and serological examination of aborted cows sera for presence of Mycoplasma antibodies. ARCHIV FUR EXPERIMENTELLE VETERINARMEDIZIN 1983; 37:429-33. [PMID: 6615139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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446
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Belagyi J, Izsak J, Juhasz-Nagy P, Varga Z. Introduction to Biomathematics. Biometrics 1982. [DOI: 10.2307/2530070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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447
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Ceizelová L, Hrubisko M, Bastrnáková E, Varga Z. [Two observations of an anti-Pr antibody (author's transl)]. CASOPIS LEKARU CESKYCH 1980; 119:1114-1115. [PMID: 6793231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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448
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Petkó M, Rigó G, Varga Z. Quantitative changes of the C-cell population in the rat thyroid during postnatal ontogenesis. Cell Tissue Res 1976; 166:541-52. [PMID: 56235 DOI: 10.1007/bf00225918] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The number and distribution of C-cells in the rat thyroid gland, have been investigated during postnatal ontogenesis from birth to 120 days of age. The argyrophilic and metachromatic properties of these cells were used to identify them. In the thyroid of newborn rats the C-cells do not exhibit argyrophilia and metachromasia. These reactions appear at 10 days and can be seen at all subsequent ages. The number of C-cells shows a parallel increase with age as demonstrated by the change in the proportion of C-cells: F-cells: colloid: stroma during development. A marked increase in C-cells was found at 50 days of age when the proportion of C-cells rose to 27.67% from the value of 16.78% at 30 days. At 70 days a decrease was noted (20.50%) which hardly changed until 120 days of age (22.20%). The numerical increase in C-cells occurs at the expense of the follicular epithelium and stroma. The C-cells occupy elongated islet-like region in the central part of the lells are present. The long axis of the C-cells area is parallel with the longitudinal axis of the lobe. The area of C-cells is largest at the centre of the lobe, corresponding to the territory of the peak of the Gaussian curve for the numerical distribution of C-cells.
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449
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Neujahr HY, Varga Z. Transport of B-vitamins in microorganisms. VII. The uptake of 14 C-niacinamide by non-proliferating cells and by protoplasts of Streptococcus faecalis. ACTA CHEMICA SCANDINAVICA 1966; 20:1529-34. [PMID: 4226091 DOI: 10.3891/acta.chem.scand.20-1529] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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450
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Cohen A, Gallagher JP, Luebs ED, Varga Z, Yamanaka J, Zaleski EJ, Bluemchen G, Bing RJ. The quantitative determination of coronary flow with a positron (rubidium-84). Circulation 1965; 32:636-49. [PMID: 4953256 DOI: 10.1161/01.cir.32.4.636] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
An objective method for the quantitative measurement of the coronary blood flow in ml./min. using a coincidence counting system with rubidium-84, a positron emitter, is described. Accidental coincidence counts arising from independent annihilation of positrons were greatly reduced by simple shielding.
The coronary blood flow was calculated by the extrapolation of the clearance values to zero time. At this time the myocardial extraction ratio of rubidium-84 is unity and clearance is equal to flow. The accuracy of this method was demonstrated on the isolated perfused dog heart.
It was found that the rate of change of the extraction ratio of rubidium-84 in the isolated perfused dog heart and in man was not altered with changes in flow.
The finding that nitroglycerin increases the coronary blood flow in patients without coronary artery disease while decreasing it in patients with coronary artery disease was confirmed.
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