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Biomedical subjects

Z Varga

Publications and source records attributed to Z Varga.

At least 127 records · Page 7Linked to original sources
PubMed1990

Cell surface markers, inositol phosphate levels and membrane potential of lymphocytes from young and old human patients.

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.

Adult↗
PubMed1990

[Injury of the rotator cuff. II. Diagnostic and therapeutic problems].

Authors examined the clinical problems of the rotator cuff injuries. The possibilities of the early diagnosis are reviewed and the significance of the detailed physical examination and of the shoulder arthrography stressed. The indication of the conservative and operative treatment is defined and also the optimal time of the reconstructive operation. In massive tears, in young age, the early diagnosis and the necessity of the urgent operations is stressed whereas in degenerative alterations, before the operative therapy of the cuff defects, in every case complex physiotherapeutic treatment is suggested. It is underlined that the operative results are improved by the good exposure, the possibly simple and reliable closure of the defect with a synchronous widening of the space under the shoulder vault. Because of the great variety of the injuries an individually chosen functional aftertreatment of many months is thought necessary.

Acromioclavicular Joint↗
PubMed1989

Identification and signal transduction mechanism of elastin peptide receptor in human leukocytes.

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.

Adult↗
PubMed1989

[Experience with the surgical management of rupture of the capsule and ligament of the acromioclavicular joint].

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.

Accidents↗
PubMed1989

Age related impairment in phosphatidylinositol breakdown of polymorphonuclear granulocytes.

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.

Adult↗
PubMed1989

Lymphocytic progesterone receptors in normal and pathological human pregnancy.

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.

Abortion, Habitual↗
PubMed1989

Unequal expression of complement C4A and C4B genes in rheumatoid synovial cells, human monocytoid and hepatoma-derived cell lines.

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.

Anaphylatoxins↗
PubMed1989

[Use of a periosteal flap in the surgical management of rupture of the acromioclavicular joint capsule and ligament. Preliminary report].

Authors use in the treatment of acromioclavicular joint dislocations to increase the safety of the ligament sutures a periosteal flap, gained from the clavicle. The use of the periosteal flap to increase the strength of the acromioclavicular ligament sutures is described. In case of fixing the joint with a tension band the suspension of the cerclage on a screw for an easier removal is suggested.

Acromioclavicular Joint↗
PubMed1989

Mycoplasma infection as disposing factor to Streptococcus dysgalactiae mastitis.

The authors studied a synergistic effect of an arginine hydrolising, but glucose negative mycoplasma strain (9293/3/2/1) and Streptococcus (Str.) dysgalactiae. Both agents, as mono-infections, caused only slight mastitis, but if the udder had been previously infected with mycoplasma, Str. dysgalactiae provoked very severe mastitis.

Animals↗
PubMed1989

Biochemical and serological study of two mycoplasma strains isolated from geese.

2 mycoplasma strains were isolated, one from the phallic lymph of a gander and the other from a cloacal swab of a laying goose. The strains proved to be different from mycoplasma species isolated from geese before. Strain No. 1223 is a glucose-negative and arginine-negative species belonging to the genus Mycoplasma. In the growth inhibition test, it fails to react with hyperimmune sera raised in rabbits against the presently known mycoplasma species of avian origin nor with sera produced against mammalian mycoplasma species sharing its biochemical properties. Strain No. 1225 belongs to the digitonin resistant Acholeplasmataceae family. It is glucose-positive and aesculin-positive. It is negative by all the other tests and fails to react with sera produced against the presently known acholeplasma species.

Acholeplasmataceae↗
PubMed1988

Effect of elastin peptides and N-formyl-methionyl-leucyl phenylalanine on cytosolic free calcium in polymorphonuclear leukocytes of healthy middle-aged and elderly subjects.

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.

Adult↗
PubMed1988

Studies on opsonized zymozan, FMLP, carbachol, PMA and A23187 stimulated respiratory burst of human PMNLs.

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.

Adult↗
PubMed1988

Human model for studying in vitro the regulating function of specific and scavenger LDL receptors.

Measurements of the specific and scavenger LDL receptor activities in different disorders do not reveal all the causes and origin of hypercholesterolaemia. Studying the failure of the intracellular regulation of these receptors can give us some new information about the background of atherosclerosis. Therefore, we have tried to develop an in vitro model which is suitable for studying the specific and scavenger LDL receptor activities and their most important regulating functions, i.e. the inhibition of HMG-Co-A reductase by native LDL and the apo E secretion induced by acLDL. MDMs cultured for three days have turned out to provide a good model to test these functions.

Antigens, Differentiation↗
PubMed1988

[Possibilities for using emergency abdominal ultrasound study and its significance in acute diseases of the abdominal cavity].

Studies were conducted by the authors' of this paper into the diagnostic value of ultrasonic examination to clear up suspicion of acute abdominal problems, with 381 examinations being actually evaluated. Definitely valid diagnosis was obtained from the method in 37.7 per cent of these cases. The tentative diagnosis was invalidated in 18.2 per cent. The results are compared with literature data. Continued systematic use of the approach is recommended. It would bring down the time required for diagnosis and might provide another possibility of supporting the diagnostic effort which is quite difficult, when it comes to acute abdominal problems.

Abdomen, Acute↗
PubMed1987

In vitro testing of the anti-mycoplasma effect of some anti-coccidial drugs.

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.

Acholeplasma↗
PubMed1987

Concentration-dependent effect of met-enkephalin on human polymorphonuclear leukocytes.

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.

Antibody-Dependent Cell Cytotoxicity↗