Biomedical subjects

A Végh

Publications and source records attributed to A Végh.

At least 19 recordsLinked to original sources

PubMed2001

Repeated biopsies in evaluation of therapeutic effects in prostate carcinoma.

BACKGROUND: Apoptosis is one of the major events following total androgen blockade (TAB). The aim of this study was to determine the predictive value of some histological parameters including apoptosis and gene products which influence apoptosis, based on repeated biopsies taken from the same patients. METHODS: At the time of diagnosis by needle biopsy TNM stage, serum PSA, Gleason's grade, apoptotic and mitotic index, Ki67, p53, and bcl(2) expression were investigated in 60 prostate carcinoma patients. Antiandrogen therapy supplemented with surgical or chemical castration was administered. Serum PSA-test and needle biopsy were repeated 13-14 weeks after starting the therapy, simultaneously with determination of the apoptotic and mitotic index, Ki67, p53, and bcl(2) expression. RESULTS: Forty-seven patients were alive at the end of the study, 13 patients died. Decrease in mitotic, increase in apoptotic index predicted favourable long-term response to antiandrogen therapy. Lower Ki67 and (mutant) p53 expression in the first and also in the second biopsy pointed to favourable effect of antiandrogen treatment. Since the ratio between Ki67 and apoptotic index strongly decreased in the survivors upon therapy, changes in Ki67/apoptosis ratio is recommended as a histologically detectable predictive factor. bcl(2) expression did not show significant correlation with the outcome of the disease. CONCLUSIONS: Histological evaluation of mitotic and apoptotic index, Ki67, and p53 expression in repeated biopsies contributes to predicting the value of the actual treatment and may be useful to institute alterations in therapy.

Age Factors↗

PubMed2001

[Prevalence of dental caries in adolescents wearing the Alexander-type fixed orthodontic device].

In the present study for an investigation regarding the oral caries in 1179 adolescents, wearing the Alexander fixed braces, aged 14.3 (+/- 1.8 years), were investigated for the DMF index. 80% of the examined children were living in the capital (Budapest) and the rest were from the countryside. All of them were treated at the Heim Pál Children's Hospital. Their orthodontic treatment was supported by the state health insurance. Out of all examined subjects 46% was recorded as caries-free and the remaining 54% showed the following distribution pattern: DMF = 1 was 16%, DMF = 2 was 14%, DMF = 3 was 7% and DMF3 < was 17%. The results do not support a judgment of 'poor level' of oral hygiene in children wearing the Alexander appliance, on the contrary, the outcome suggest an acceptable level of oral hygiene as well as educated oral- and dental attitude in adolescents treated with malocclusions, which are mostly regarded as a risk factor for caries inductive dental plaque formation. The results also indicates that the claim for orthodontic treatment might have had a positive effect on caries prevalence.

Adolescent↗

PubMed2001

[Clinical problems of orthodontics and orofacial orthopedics at the turn of the millennium].

The author gives an overview of orthodontic profession among the dental specialties. Educational problems of orthodontics in the new age are also discussed as well as treatment quality assurance possibilities and conditions. Future treatment possibilities of retrospectively rehabilitative adult orthodontics and interceptively prospective early treatment of children are referred. The article also cover the 3D imaging of the human face, animation of the craniofacial complex, and Cephalometric 3D analysis as areas of scientific research and realities. The need for restandardizing of orthodontic slot size to simplify and to minimize changeover problems in orthodontics basic hardware--the wires and brackets--are also addressed.

Humans↗

PubMed2000

Improving diagnostic accuracy of prostate carcinoma by systematic random map-biopsy.

Systematic random rectal ultrasound directed map-biopsy of the prostate was performed in 77 RDE (rectal digital examination) positive and 25 RDE negative cases, if applicable. Hypoechoic areas were found in 30% of RDE positive and in 16% of RDE negative cases. The score for carcinoma in the hypoechoic areas was 6.5% in RDE positive and 0% in RDE negative cases, whereas systematic map biopsy detected 62% carcinomas in RDE positive, and 16% carcinomas in RDE negative patients. The probability of positive diagnosis of prostate carcinoma increased in parallel with the number of biopsy samples/case. The importance of systematic map biopsy is emphasized.

Aged↗

PubMed2000

[Experimental and finite-element models for the assessment of mandibular deformation under mechanical loading].

Biomechanical investigations of the mandible are difficult to perform due to a variety of conditions involved. For the appropriate reconstruction of biomechanical properties, a geometrically correct body model has to be established which fits to complex in vivo conditions. The aim of our study was to evaluate the use of finite-element models (FEM) for the assessment of mandibular deformation under mechanical loading. Explanted human mandibles (n = 5) were investigated by strain gauges to determine the individual strain distribution under mechanical loading. FEM analysis based on a computed tomograph (CT) was performed and the results were matched with the test data. Our study demonstrates only minor interindividual differences in the strain distribution for each load studied. The mechanical response in terms of deformation was found to depend mainly on gross geometrical properties and to a minor extent on the various other variables. At all positions the maximum principal strain was tensile, the minimum principal strain was compressive, and the absolute strain values were correlated with the magnitude of the applied force. CT-based FEM analysis revealed the utility of mathematical models to approximate simulated data our experimental results. Hence, FEM analysis is a non-invasive tool in the prediction of biomechanical behaviour of individual mandibles and therefore may help in trauma reconstruction and treatment planning.

Biomechanical Phenomena↗

PubMed2000

Atrial natriuretic peptide reduces the severe consequences of coronary artery occlusion in anaesthetized dogs.

The aim of the present study was to examine the effects of atrial natriuretic peptide (ANP) on the responses to coronary artery occlusion. In chloralose-urethane anaesthetised mongrel dogs either saline (controls) or human synthetic ANP was infused intravenously (10 microg kg(-1) + 0.1 microg kg(-1) min(-1)), starting 30 min before and continuing 10 min during a 25 min occlusion of the left anterior descending coronary artery (LAD). ANP infusion resulted in a fall in mean arterial blood pressure (by 17 +/- 2 mmHg, p < 0.05), a transient (max. at 5 min) increase in coronary blood flow (by 24 +/- 5 ml min(-1), p < 0.05), and a reduction in coronary vascular resistance (by 0.27 +/- 0.05 mmHg ml(-1), p < 0.05). When the LAD coronary artery was occluded, there was a less marked elevation in left ventricular end-diastolic pressure (LVEDP) in the ANP-treated dogs than in the controls (9.0 +/- 0.9 versus 12.2 +/- 0.8 mmHg, p < 0.05). Compared to the controls, ANP reduced the number of ventricular premature beats (VPBs, 26 +/- 12 versus 416 +/- 87, p < 0.05), the number of episodes of ventricular tachycardia per dogs (VT, 0.7 +/- 0.3 versus 12.4 +/- 4.2, p < 0.05), and the incidences of VT (45% versus 100%, p < 0.05) and ventricular fibrillation (VF 18% versus 57%, p < 0.05) during occlusion. Reperfusion of the ischaemic myocardium at the end of the occlusion period led to VF in all the control dogs (survival from the combined ischaemia-reperfusion insult was therefore 0%), but VF following reperfusion was much less in the dogs given ANP (survival 64%; p < 0.05). The severity of myocardial ischaemia, as assessed from changes in the epicardial ST-segment and the degree of inhomogeneity, was significantly less marked in dogs given ANP. We conclude that ANP protects the myocardium from the consequences of myocardial ischaemia resulting from acute coronary artery occlusion and reperfusion in anaesthetized dogs.

Analysis of Variance↗

PubMed2000

Isosorbide-2-mononitrate reduces the consequences of myocardial ischaemia, including arrhythmia severity: implications for preconditioning.

The effects of the intracoronary administration of isosorbide-2-mononitrate (ISMN; 3 microg kg(-1) min(-1)), a major metabolite of isosorbide dinitrate, were examined in chloralose-urethane anaesthetized dogs before and during a 25 min, acute occlusion of the left anterior descending coronary artery. The only significant haemodynamic effects of ISMN administration were a slight (-11 +/- 2 mmHg) decrease in arterial blood pressure and a decrease (< 12%) in diastolic coronary vascular resistance. Coronary occlusion in the presence of ISMN led to a markedly reduced incidence and severity of ventricular arrhythmias compared to those in control, saline-infused dogs. There were fewer ectopic beats (62 +/- 35 versus 202 +/- 72; p < 0.05), a lower incidence (25% versus 75%; p < 0.05) and number of episodes (0.7 +/- 0.4 versus 4.3 +/- 2.1; p < 0.05) of ventricular tachycardia and fewer dogs fibrillated during the ischaemic period (17% versus 82%; p < 0.05). More dogs given ISMN survived the combined ischaemia-reperfusion insult (50% versus 0%; p < 0.05). Changes in ST-segment elevation (recorded by epicardial electrodes) and in the degree of inhomogeneity of electrical activation within the ischaemic area were much less pronounced throughout the occlusion period in dogs given ISMN. These results add weight to the hypothesis that the previously reported antiarrhythmic effects of ischaemic preconditioning, and of the intracoronary administration of nicorandil, involve nitric oxide.

Animals↗

PubMed1999

Delayed protection against ventricular arrhythmias by monophosphoryl lipid-A in a canine model of ischaemia and reperfusion.

Bacterial endotoxin reduces the severity of ventricular arrhythmias which occur when a coronary artery is occluded several hours later. We have now examined in anaesthetised dogs the effects on ischaemia and reperfusion-induced arrhythmias, of a non-toxic derivative component of the endotoxin molecule of the lipid-A (monophosphoryl lipid-A). This was given intravenously, in doses of 10 and 100 microg kg(-1), 24 h prior to coronary artery occlusion. Arrhythmia severity was markedly reduced by monophosphoryl lipid-A. During ischaemia, ventricular premature beats were reduced from 315+/-84 in the vehicle controls to 89+/-60 (with the lower dose of monophosphoryl lipid-A) and 53+/-23 (P<0.05) with the higher dose. The incidence of ventricular tachycardia was reduced from 75% to 25% (P<0.05) and 31% (P<0.05), and the number of episodes of ventricular tachycardia from 13.4+/-4.9 per dog to 1.1+/-1.1 (P<0.05) and 1. 2+/-0.9 (P<0.05) after doses of 10 and 100 microg kg(-1), respectively. The incidence of ventricular fibrillation during occlusion and reperfusion in the control group was 96% (15/16), i.e., only 6% (1/16) dogs survived the combined ischaemia-reperfusion insult. Monophosphoryl lipid-A (100 microg kg(-1)) significantly reduced the incidence of occlusion-induced ventricular fibrillation (from 50% to 7%; P<0.05), and increased survival following reperfusion to 54% (P<0.05). Monophosphoryl lipid-A also significantly reduced ischaemia severity as assessed from ST-segment elevation recorded from epicardial electrodes as well as the degree of inhomogeneity of electrical activation within the ischaemia area. There were no haemodynamic differences prior to coronary occlusion between vehicle controls and monophosphoryl lipid-A-treated dogs. These results demonstrate that monophosphoryl lipid-A reduces arrhythmia severity 24 h after administration. Although the precise mechanisms are still unclear, there is some evidence that nitric oxide and prostanoids (most likely prostacyclin) may be involved because the dual inhibition of nitric oxide synthase and cyclooxygenase enzymes by administration of aminoguanidine and meclofenamate abolished the marked antiarrhythmic protection resulted from monophosphoryl lipid-A treatment 24 h previously.

Animals↗

PubMed1999

Repeated cardiac pacing extends the time during which canine hearts are protected against ischaemia-induced arrhythmias: role of nitric oxide.

Right ventricular pacing in lightly anaesthetized dogs (4x5 min periods at a pacing rate of 220 beats/min) protects against the consequences of coronary artery occlusion when this is initiated 24 h after the pacing stimulus. The main purpose of the present experiments was to determine whether repeating the pacing stimulus, at a time when protection from the initial stimulus had faded (48 h), prolonged the protection afforded against ischaemia-induced ventricular arrhythmias and other ischaemic changes (epicardial ST-segment mapping; changes in the degree of electrical inhomogeneity in the ischaemic region). Dogs were paced on two occasions, with a 48 h period between and, at different times (48, 72 and 96 h) after the second pacing stimulus, were re-anaesthetized and subjected to occlusion of the left anterior descending coronary artery. There was a marked reduction in the severity of ischaemia-induced arrhythmias 48 and 72 h after the second pacing stimulus (reduction in occlusion-induced and reperfusion-induced ventricular fibrillation, e.g. at 72 h 0/11 during occlusion and only 3/11 following reperfusion, compared to 7/21 and 10/21 respectively in the controls P<0.05). The protection had disappeared 96 h following the second pacing stimulus. Changes in ST-segment elevation and in the degree of inhomogeneity largely followed these changes in the severity of ventricular arrhythmias. The results suggest the possibility of maintaining protection against life-threatening arrhythmias following coronary occlusion by repeating a preconditioning pacing stimulus. We also demonstrate that this prolonged protection afforded by repeated cardiac pacing is mediated by nitric oxide, since the marked antiarrhythmic effect observed, e.g. 72 h after the second pacing stimulus, was abolished when S-(2-aminoethyl)-isothiourea (AEST), a particularly selective inhibitor of iNOS, had been administered before coronary artery occlusion.

Animals↗

PubMed1999

Pacing-induced delayed protection against arrhythmias is attenuated by aminoguanidine, an inhibitor of nitric oxide synthase.

1. Cardiac pacing, in anaesthetized dogs, protects against ischaemia and reperfusion-induced ventricular arrhythmias when this is initiated 24 h after the pacing stimulus. Now we have examined whether this delayed cardioprotection afforded by cardiac pacing is mediated through nitric oxide. 2. Twenty-two dogs were paced (4 x 5 min periods at 220 beats min(-1)) by way of the right ventricle, 24 h prior to a 25 min period of coronary artery occlusion. Nine of these dogs were given the inhibitor of induced nitric oxide synthase, aminoguanidine (50 mg kg(-1) i.v.), 0.5 h prior to coronary artery occlusion. Sham-operated non-paced dogs with and without aminoguanidine treatment served as controls. 3. Pacing markedly (P<0. 05) reduced arrhythmia severity (ventricular fibrillation, VF, during occlusion 15%; survival from the combined ischaemia-reperfusion insult 62%) compared to control, sham-operated, unpaced dogs (VF during occlusion 58%; survival 17%). This protection was attenuated by the administration of aminoguanidine prior to coronary artery occlusion (survival from the combined ischaemia-reperfusion insult 11%, which was significantly (P<0.05) less than in the paced dogs not given aminoguanidine and similar to the controls). Aminoguanidine had no significant effects on coronary artery occlusion when given to dogs that had not been paced. In the dose used aminoguanadine transiently elevated systemic arterial pressure by a mean of 20 mmHg and reduced heart rate by a mean of 22 beats min(-1). 4. These results suggest that nitric oxide, probably derived from induced nitric oxide synthase, contributes significantly to the delayed cardioprotection afforded by cardiac pacing.

Animals↗

PubMed1999

[The development and action-mechanism of the quadhelix in orthodontic treatment].

Authors present a historical review of the development of quadhelix appliance. In conclusion, slow maxillary expansion with the quadhelix appliance provides an alternative approach to rapid maxillary expansion that is particularly beneficial for correction of transverse and arch-length discrepancies during the mixed dentition. There are numerous indications for this approach with two major advantages. First, a lower force that is within the elastic limits of maxillary sutural and periodontal tissue is generated. Second, a low separation rate of 0.4-1.1 mm per week allows for more physiologic adaptation to the expansion that may result in a more stable correction with less sutural relapse. The quadhelix is a versatile appliance that provides practitioners a convenient means to normalize developing malocclusions.

Humans↗

PubMed1998

The dopamine receptor agonist Z1046 reduces ischaemia severity in a canine model of coronary artery occlusion.

Z1046, (S)-6[[6-[[2-(2-methoxyphenoxy)ethyl]amino]propyl]amino]-5,6,7,8-tetra-h ydro-1,2-naphtalenediol dihydrochloride, is an agonist at both dopamine D1 and D2 receptors. Since stimulation of dopamine D2 receptors inhibits noradrenaline release, and because cardiac noradrenaline release has been implicated in the genesis of early ischaemia-induced, life-threatening ventricular arrhythmias, the effect of Z1046 has been examined for its effects on coronary artery occlusion in chloralose urethane anaesthetised mongrel dogs. Z1046 (10 microg kg(-1) intravenously or 1 microg kg(-1) by local intracoronary injection) decreased heart rate and reduced arterial blood pressure and coronary blood flow, effects prevented by the prior administration of domperidone (40 microg kg(-1) i.v.). The ischaemic changes induced by a 25-min occlusion of the left anterior descending coronary artery (including ST-segment elevation and ventricular ectopic activity) were much less marked in those dogs administered Z1046 and survival from the combined ischaemia reperfusion insult was increased from 7% to 36% (P < 0.05). These effects of Z1046 were partly attenuated by domperidone. We conclude that the anti-ischaemic effects of Z1046 are due to inhibition of cardiac sympathetic responses. Studies using rat isolated perfused mesenteric vascular bed preparations subjected to sympathetic nerve stimulation confirmed that Z1046 inhibits synaptic transmission without modifying vascular responses to noradrenaline.

Animals↗

PubMed1998

Biopsy-based diagnosis of prostate cancer in 1290 patients referred for prostate examination: results according to the PSA level, digital rectal examination and ultrasonography.

Authors present their retrospective study of 1290 patients referred for prostate evaluation. The risk of cancer was analysed according to PSA, rectal palpation and ultrasound examination. Among the 1290 patients, 54.8% had cancer. The risk of cancer was multiplied by 2.8 when the PSA was between the normal limit and 10 ng/ml, by 7.5 when it exceeded 10 ng/ml, by 4.0 when rectal palpation was abnormal and by 1.6 when a hypoechogenic zone was present. Although a hypoechogenic zone does not improve the detection of cancer compared to PSA and rectal palpation, an increased PSA level even lower than 10 ng/ml indicates biopsies.

Adult↗

PubMed1997

Modification by bradykinin B2 receptor blockade of protection by pacing against ischaemia-induced arrhythmias.

In dogs, rapid cardiac pacing, by way of a pacing electrode in the right ventricle, protects against ventricular arrhythmias when a coronary artery is occluded immediately after cessation of the pacing period. This represents a form of ischaemic preconditioning. The role of bradykinin in mediating the protective effects of rapid cardiac pacing in this model was investigated using a selective antagonist of bradykinin at B2 receptors (icatibant; HOE 140). In the presence of icatibant cardiac pacing (220 beats min(-1)) resulted in more severe ischaemia (as assessed by ST-segment elevation from the pacing electrode at the end of the stimulus) and to a higher incidence of ventricular arrhythmias during the pacing protocol. When the coronary artery was occluded under such conditions the antiarrhythmic protection afforded by cardiac pacing was not seen although other indices of reduced ischaemia severity (epicardial ST-segment mapping; changes in the degree of inhomogeneity of electrical activation within the ischaemic area) were not affected by icatibant treatment. These results suggest that bradykinin is an important trigger mediator involved in the protective effects of cardiac pacing. Whether this is due to the generation of endothelium-derived protective substances (such as nitric oxide and prostacyclin) or whether it results from a direct effect on B2 receptors in cardiac myocytes is unclear.

Adrenergic beta-Antagonists↗

PubMed1997

Two methods in the treatment of prostate cancer T1-T2.

The author reports experience of 82 radical retropubic prostatectomies. In accordance with the length of isolable urethra two methods were applied. In one of the methods the bladder-neck was pulled down to the floor of the pelvis by a synthetic reabsorbable thread (40 cases), in the other method, the urethra-trunk was sewn up to the bladder-neck (42 cases). The early and later complications are dealt with. Their findings: the blood transfusion during intra and perioperative period was identical in both methods. Injury of ureter did not occur, injury of rectum in one case (1.2%) occurred. In the two methods incidence of impotence (85%) and incontinence (15%) were identical. The length of operation was on an average twenty minutes shorter in the pull-down technique but stricture occurred in 4.7%. In the sewing method no stricture occurred. In the opinion of the author the pull-down technique at the short (5-7 mm) urethra-trunk, while the direct sewing-up technique at the long (7-20 mm) urethra-trunk were applied.

Absorption↗

PubMed1996

Haemodynamic and other effects of sulphonylurea drugs on the heart.

Antidiabetic sulphonylureas have attracted a great deal of interest in experimental cardiology to evaluate the role of ATP-sensitive potassium channels in the cardiovascular system. It is well established that KATP channels are present in cardiac cells and also in vascular smooth muscle cells and are implicated in the regulation of myocardial and vascular function. It follows that drugs which open, or inhibit the opening of these channels, might profoundly modify cardiovascular function both under physiological and pathophysiological conditions. This paper reviews the evidence for the role of KATP channels in the cardiovascular system and discusses how the different generations of sulphonylurea drugs interfere with cardiac function. We will particularly concentrate on the haemodynamic effects of different sulphonylureas and shortly discuss how these drugs modify ischaemia-reperfusion arrhythmias.

Adenosine Triphosphate↗

PubMed1996

Cardiovascular effects of conventional sulfonylureas and glimepiride.

Sulfonylureas have, in the past, been reported to have adverse cardiovascular effects. Glimepiride is a new sulfonylurea. In spite of stimulating less insulin secretion, it has, depending on the species, equal or higher blood glucose decreasing activity and according to preliminary studies less cardiovascular activity than glibenclamide. Further studies were performed to confirm the lower cardiovascular activity of glimepiride. The IC50 for inhibition of rilmakalim-activated KATP channel currents in isolated ventricular myocytes was 31.6 nM for glimepiride and 6.8 nM for glibenclamide. In endotoxin shock-rats at a dose of 1 x 2 mg/kg i.v., glibenclamide induced a significantly higher blood pressure increase than glimepiride. At two i.v. doses of 20 mg/kg 4 min apart, in normal rats, glibenclamide produced signs of ischemia in the ECG in nearly all animals, glimepiride almost none, in diabetic rats, glibenclamide produced in all animals a lethal cardiogenic shock preceeded by serious ECG changes, glimepiride only in one fifth of the animals. In open-chest dogs, on intracoronary infusion of equieffective blood glucose-lowering doses, glibenclamide, gliclazide and glimepiride all reduced coronary blood flow, increased coronary resistance, depressed the mechanical activity of the heart, enhanced myocardial O2-extraction, reduced the serum potassium level and induced a moderate endocardial ST-segment elevation, but glimepiride to a significantly less extent than glibenclamide and gliclazide. The presented data confirm that glimepiride at equivalent blood glucose decreasing doses has less cardiovascular activity than conventional sulfonylureas.

Animals↗

PubMed1995

[Transrectal ultrasonography in the diagnosis of prostatic cancer].

There is a summary of experience with 771 transrectal ultrasound examinations. According to the authors, this picture forming method is one of the best diagnostical methods in the malignant tumors of the prostate. In every case, when the digital rectal examination is positive and the serum prostate specific antigen level is above 4 ng/ml, the transrectal ultrasonography should be done as well as the ultrasound guided biopsy of prostate. Besides of these facts, the transrectal ultrasound is useful in the following process of the drug- and/or the radiotherapy for the measurement of the therapeutical effect and the perceptions of recidives.

Aged↗