Biomedical subjects

Z Varga

Publications and source records attributed to Z Varga.

At least 109 records · Page 6Linked to original sources

PubMed1993

Age-dependent changes in transmembrane signalling: identification of G proteins in human lymphocytes and polymorphonuclear leukocytes.

In human neutrophils (PMNLs) we found that in the elderly IP3 formation was significantly decreased compared to that of young subjects. For FMLP receptor binding affinity and number no measurable differences occurred upon ageing, studying both the low or the high affinity receptors. The amount of ADP-ribosylated G proteins, catalysed by pertussis toxin (PT) or cholera toxin (CT), was significantly increased in PMNLs of the elderly. In lymphocytes, the PT-catalysed ADP ribosylation of G proteins was also increased with ageing, while the CT-catalysed ribosylation was decreased. The autoradiogram of [32P]ADP-ribosylated proteins by CT in lymphocytes of young individuals showed a major polypeptide of 40,000 M(r). In contrast, in lymphocytes of the elderly, the major polypeptide was 45,000 M(r). In PMNLs, CT labelled quite strongly the 45,000 M(r) band, mainly in the elderly. When PT was used, no age-related pattern changes could be demonstrated, while differences could be observed between the two types of cells. The use of antiserum P680 (G alpha common) showed no age-related pattern changes, while the intensity of the labelled proteins varies with age and cell type. The antiserum U46 (Go alpha) could identify in lymphocytes of young subjects two polypeptides 68,000 and 41,000 M(r). The prominent polypeptide in lymphocytes of the elderly was the 70,000 M(r) and no other polypeptides could be recognized. In PMNLs of young subjects the U46 and serum identified a range of species. In PMNLs of the elderly all these bands were weakly labelled. The present data indicate changes in the pattern and the quantity of G proteins in lymphocytes and PMNLs of elderly subjects.

Adenosine Diphosphate Ribose↗

PubMed1993

Similarity of an oviduct-specific glycoprotein between different species.

The oviduct provides the best environment in which a zygote can grow and it can also support the development of embryos from a different species. However, there is no clear explanation of its embryotrophic properties at present. In several species, oviduct epithelial cells synthesize and secrete glycosylated proteins that become associated with developing embryos. Although these macromolecules may have a functional role at the time of fertilization and early embryonic development, the nature of such a role remains to be elucidated. The aim of this work was to perform a comparative analysis of oviduct-specific glycoproteins in search of molecules common to different species since their phylogenetic conservation would imply biological significance. In previous studies, sheep oviduct-specific proteins were characterized and a monoclonal antibody (AFRC MAC 264) specific for the sheep oviduct protein 92 (sOP 92) was produced; hence, sheep was taken as the reference species. The degree of similarity between sheep glycoproteins and those of the cow, goat, pig, rabbit and mouse was determined on the basis of: the presence of carbohydrate side-chains, cross-reactivity with AFRC MAC 264, correspondence of molecular weight between cross-reacting molecules, and similarity of immunohistochemical localization. On this basis, proteins similar to sOP 92 were present in cow and goat oviduct. A more limited similarity was also observed in pigs. This indicates a certain degree of phylogenetic conservation and suggests that these molecules may play an important physiological role; however, their function remains to be determined.

Animals↗

PubMed1993

Influence of age on the signal transduction of T cells in mice.

A 5- to 10-fold decline was observed in the proliferative activity of T cells stimulated with anti-CD3 mAb between young and old mice. However, the number of CD3 molecules on the T cell surface was almost comparable between young and old T cells. The formation of the second messenger such as inositol triphosphate (IP3) and diacylglycerol (DAG) after mitogenic stimulation decreased in old T cells as compared with young ones. The activity of phospholipase C (PLC), which is responsible for the liberation of IP3 and DAG from phosphatidylinositol-4,5-bisphosphate (PIP2) was not different between young and old T cells. The content of PIP2 in the membrane was also comparable between young and old T cells. These findings have suggested that the age-related decline in the proliferative activity of T cells could be due to impairment of intracellular signal transduction, probably in the pathway somewhere between TCR and PLC.

Aging↗

PubMed1993

Biopsy and sex determination by PCR of IVF bovine embryos.

Sex of early bovine embryos was determined by polymerase chain reaction (PCR) using a single blastomere removed at the 16-32 cell stage. Embryos were produced in vitro and biopsied on the fifth day after in vitro fertilization. Biopsied embryos were cultured on a cumulus cell monolayer until embryo transfer. For the PCR, one pair of bovine-specific and one pair of Y-chromosome-specific primers were used. Definite signals following PCR amplification were obtained in 95.4% of cases indicating that one blastomere from a preimplantation bovine embryo is sufficient for sex determination by PCR. Nineteen biopsied embryos of predetermined sex were transferred into synchronized recipient females to examine their developmental potential in vivo. Ten of the recipients (52.6%) were found to be pregnant by ultrasonography 25 days after transfer. This result did not differ significantly from that achieved with the use of the control non-manipulated IVF embryos (54.1%; P > 0.1).

Animals↗

PubMed1993

Preliminary experience of angioscopy in femorodistal bypass.

During femorodistal bypass angioscopy can be used in vein graft preparation allowing valve lysis and the identification of tributaries under direct vision. A total of 30 patients have undergone angioscopic assisted femorodistal bypass using either an Olympus or Stortz system. Nineteen patients have undergone full vein mobilisation and valve lysis under direct vision. Eleven patients had in situ bypass with ligation of tributaries, identified by the angioscope, through small stab incisions. No evidence of fistula or retained valve cusps was found by subsequent duplex scanning and arteriography. One of these grafts failed at 6 days due to an unrecognised outflow stenosis. The mean hospital stay after operation for this latter group of patients was 5.2 days (range 4.4-6.0 days) compared with 9.5 days (8.6-10.3 days) in a historical group of 30 patients (P < 0.001). Angioscopy is a useful aid in the performance of femorodistal bypass. Early experience suggests that hospital stay may be reduced by angioscope assisted in situ femorodistal bypass because of the minimal dissection involved.

Adult↗

PubMed1992

Transmembrane signaling changes with aging.

Altered immune response and transmembrane signaling with aging has previously been demonstrated. The aim of the present study was to characterize PMNLs and lymphocyte G proteins and to determine whether their relative amounts are altered with aging. First we studied the effects of FMLP on PMNLs IP3 formation. It was found that in any group of elderly the PMNLs IP3 formation was significantly decreased compared to that of young subjects. In FMLP receptor binding affinity no measurable difference exists in either low- or high-affinity FMLP receptors. The autoradiogram of 32P-ADP-ribosylated proteins by CT in lymphocytes of young individuals showed a major polypeptide of 40 kDa, and two much less prevalent components of 52 and 45 kDa. In contrast, in lymphocytes of elderly subjects the major polypeptide was 45 kDa, and the two others were very weakly labeled. In PMNLs, CT labeled the 45-kDa band quite strongly, mainly in the elderly, and the 52- and 40-kDa bands were very weakly labeled, mainly in young subjects. When PT was used, no age-related pattern changes could be demonstrated, while differences could be observed between the two types of cells.

Adenosine Diphosphate Ribose↗

PubMed1992

Embryos derived from the in vitro fertilization of oocytes of pregnant cows.

The aim of our study was to determine if the oocytes of pregnant cattle are capable for undergoing embryonic growth following in vitro fertilization. The ovaries of nine heifers at 4 to 7 months of pregnancy were collected at an abattoir and transferred to the laboratory. A total 191 oocytes (10.6 per ovary) collected by aspiration were matured and fertilized by frozen-thawed semen. Embryos were co-cultured with granulosa cells in modified TCM 199 medium and 20% estrous cow serum. The cleavage rate of embryos was 48%, and 41% of of the cleaved embryos developed to the morula/blastocyst stage 7 days after insemination. Additionally, the ovaries of 10 nonpregnant heifers were also collected, yielding 213 oocytes (10.7 per ovary). The cleavage rate was 51%, and 35% of those which cleaved reached the morula/blastocyst stage. No significant differences were found between the two groups. The average number of transferable-stage embryos obtained from pregnant and nonpregnant animals was 4.1 and 3.7, respectively. Our results indicate that preganancy does not influence the meiotic competence of bovine oocytes, and transferable stage embryos can be obtained by the fertilization of oocytes derived from pregnant animals.

Journal Article↗

PubMed1992

Efficacy and tolerance of roxithromycin in comparison with erythromycin stearate in patients with lower respiratory tract infections.

The efficacy and tolerance of roxithromycin 150 mg b.i.d. were compared with those of erythromycin stearate 500 mg b.i.d. in patients with lower respiratory tract infections. Out of 86 patients recruited for the study, 79 were evaluable for tolerance and 76 for efficacy. These patients were evenly distributed among the 3 investigational clinics, with 26, 25 and 28 patients, respectively. The diagnosis of lower respiratory tract infections was based on clinical, laboratory, radiological and/or physical findings and, when available, bacteriological and serological findings. The duration of treatment was 10 days, with follow-up at post-treatment visits directly after treatment and 6 weeks thereafter. The clinical outcome was satisfactory with no significant difference between the drugs. More patients reporting adverse events were on erythromycin than on roxithromycin (51.3% vs 17.5%; p = 0.003). The results suggest that roxithromycin is as effective as erythromycin stearate in the treatment of lower respiratory tract infections and causes fewer adverse effects.

Adult↗

PubMed1992

[Stabilization of the injured acromioclavicular joint using a new type of fixation plate].

The opinions in the question of transitory fixation of the joint during the treatment of the acromioclavicular articulation are rather different. The complications of the widely used methods--break of the implant, its tear from the bone, the wandering and the disturbances of wound healing--are well known. To decrease the number of complications authors have developed a new type of hooked plate. The plate is fitted to the anterior surface of the acromial end of the clavicle and its hook is fixed from below in the bore hole of the acromion. To choose the optimal place of the bore hole a drill guide was prepared. The operative method is described and the advantages of the method are summarized. The "Debrecen-plate" was used during 2 years in 39 injuries. 35 patients were controlled 6-24 months after the operation. Based on the results of the treatment a wider use of the method is suggested.

Acromioclavicular Joint↗

PubMed1992

[Experience with the management of scapula fractures].

Authors have treated 37 fractures of the scapula during 3 years. The questions of the aetiology, classification, diagnosis and therapy of this injury are reviewed. It is stated that the majority of the scapula fractures heal on conservative therapy; in consequence the functional treatment has a leading role. The fractures of the articular surfaces with step formation, the fractures of the scapular neck process dislocated in a high degree, or unstable fractures of the scapular neck combined with the comminutive fractures of the operative therapy are assessed. Attention is called to the most frequent operative complications and to the possibility of their prevention.

Bone Nails↗

PubMed1992

[Experience with the Bristow procedure].

Authors assess the results of 17 Bristow's operations performed in the therapy recurrent anterior dislocation of the shoulder. The literature of the subject is reviewed, the technical details of the operations are described and the possibilities of complications are pointed out. On the basis of literary data and their own favourable experiences the wider use of this method is suggested.

Female↗

PubMed1992

Primary malignant tumours associated with thyroid carcinoma in autopsy material.

In our Department 37,504 autopsies were performed in the last 30 years. Double multiple primary malignant tumours were found in 385 cases (4.2% of the cases with malignant tumours). In thyroid cancer cases, tumours of other organs were more frequent (20 cases, 22.7%), and these tumour associations were observed mainly simultaneously; there were no significant sex differences. In the more frequent synchronous cases, the thyroid cancer was a tumour only accessory to other malignancies; in the rarer metachronous cases, the thyroid cancer was secondary to postoperative irradiation of the first tumour (4 of 5 cases). Thyroid cancers were seen most frequently together with lung, breast and digestive system tumours; there was no special association recognizable to certain other malignancies. Follicular carcinoma was more frequent among the cancers associated with another tumour (12 of 20 cases), while in general the papillary was the most frequent type (48 of 88 cases).

Aged↗

PubMed1991

[Malignant tumors associated with thyroid cancer in an autopsy material].

In the Department of Pathology of Albert Szent-Györgyi Medical University at Szeged in Hungary 37,504 autopsies were performed in the last 30 years and double multiple primary malignant tumours were found in 385 cases (4.2%). In thyroid cancer cases the tumours of other organs were more frequent (22.7%), and these tumour-associations were observed mainly simultaneously, there were no important sex differences. In the most of cases the thyroid cancer was only a side diagnosis beside other malignancies, in the more rare metachronous cases the thyroid cancer was secondary following postoperative irradiation of the first tumour (4 cases of 5). We have seen thyroid cancers most frequently together with lung, breast and digestive system tumours.

Aged↗

PubMed1991

[The use of Debrecen plates in the management of acromioclavicular dislocation].

Since surgical treatment of the ruptured acromio-clavicular ligaments is still requiring an improvement, a new implant, the Debrecen-plate, was devised. Its application necessitates only a small exposure, soft tissue covers the plate favourably and spares the joint surface from immediate damage. The authors describe the surgical procedure and report on the outcome of 39 Tossy II and III injuries treated in this way.

Acromioclavicular Joint↗

PubMed1991

[First experiences in Hungary with the use of the Wolter plate in acromioclavicular dislocations].

Authors describe an operative procedure, new in this country, for the treatment of acromioclavicular dislocation. In 18 young sportsmen and physical workers, in cases of injury, the joint was fixed with Wolter's crooked plate until the healing of the capsule and ligament sutures. The plate does not damage the joint surfaces, no postoperative external immobilization is necessary and so early functional treatment will be possible. The patients were reexamined 24 months after the operation. No break or loosening of the implant was observed. In spite of the fact that the subcutaneous dehiscence of the wounds on shorter sections healed without complications further investigations are thought necessary for its prevention. In 17 patients complete function of the shoulder was reached. All patients continue their original jobs or sport activity. On the basis of the convincing good results authors suggest the use of Wolter's plate.

Accidents, Occupational↗

PubMed1991

[Stabilization of the injured acromioclavicular joint].

Authors review the functional anatomy of the sternoclavicular joint and the pathophysiological changes in injuries of the capsule and ligaments. The advantages and complications of the operative methods used for temporary stabilization of this joint are examined. It is stated that methods, the most generally used in the past decade were not suitable to solve the question of stabilization optimally. New possibilities are promised by the hinge and hooked plates, a therapy ensuring movement and loading stability, however little experience was yet gained with their use.

Acromioclavicular Joint↗

PubMed1990

Altered phosphatidylinositol breakdown after K-elastin stimulation in PMNLs of elderly.

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.

Age Factors↗

PubMed1990

Disturbed intracellular calcium-related processes of hepatocytes and neutrophils in human alcoholic liver disease.

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.

Adult↗