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Biomedical subjects

T Fazekas

Publications and source records attributed to T Fazekas.

At least 19 recordsLinked to original sources

[Scientometric and publication malpractices. The appearance of globalization in biomedical publishing].

Attention is drawn to publication and scientometric malpractices utilized by biomedical authors who do not adhere to the accepted ethical norms. The difference between duplicate/redundant and bilingual publications is defined. In the course of discussion of the manipulations that may be observed in the field of scientometry, it is pointed out that abstract of congress lectures/posters can not be taken into consideration for scientometric purposes even if such abstracts are published in journals with impact factors. A further behavioral form is likewise regarded as unacceptable from the aspect of publication ethics: when a physician who has participated in a multicentre, randomized clinical trial receives recognition (in an appendix or in an acknowledgement of an article) as having contributed data, but assesses this appreciation as co-authorship and thereby attempts to augment the value of his or her publication activity. The effects of globalization on biomedical publication activity are considered, and evidence is provided that the rapidly spreading electronic publication for a give rise to new types of ethical dilemmas. It is recommended that, in the current age of Anglo-American globalization, greater emphasis should be placed on the development of medical publication in the mother tongue (Hungarian).

Bibliometrics↗

[Antireflux procedures at our unit (1990-1999)].

UNLABELLED: A retrospective analysis was carried out to evaluate the changing attitude of antireflux surgical practice of the authors. Between 1990 and 1994 24 antireflux procedures were performed. Laparoscopic antireflux surgery was introduced in 1995. Since then 41 laparoscopic and 23 open repairs have been performed. Indication for surgery was always based on thorough preoperative examination protocol including functional tests of the esophagus. Each patients had undergone endoscopic and X-ray examinations. The patients are under continuous follow-up surveillance. During the postoperative follow-up studies more than 2/3 of the patients (61 patients) agreed to carry out the functional tests postoperatively. RESULTS: The demographic data of patients of the two study periods proved to be comparable. The length of history was 10.5 years in the first group, while it was 8.9 years in the second group. In both groups the surgical repair caused significant reflux control confirmed by decrease of reflux index and number of reflux episodes furthermore by increase of resting lower esophageal sphincter pressure. Actually 4 recurrences are known in the first group and 2 in the second group. One of the 4 recurrences observed in the first period was treated by redo surgery. The patients having recurrences in the second period can easily be managed by medical therapy. There was no mortality and severe morbidity during the study periods. Few patients reported mild temporary dysphagia. CONCLUSIONS: In a given proportion of reflux patients the individually planned and perfectly performed antireflux surgery offers an acceptable definitive treatment option. The availability of endoscopic surgery enhances this trend, which can be seen all over the world. An increase can be seen in the number of procedures: nearly three times more patients were operated on during the second period. The early clinical results of laparoscopic antireflux procedures are good enough. Good long-term results can be expected if we accept and apply the basic technical principles determined during the open surgery era.

Adolescent↗

[Electrocardiographic Osborn wave in hypothermia].

The authors report the first Hungarian case of electrocardiographic Osborn wave with accidental hypothermia (core temperature 32 degrees C). The cellular and ionic mechanisms of the development of J-wave-elevation and the cardiac electrophysiological and ECG changes caused by hypothermia are briefly reviewed. An account is presented of those conditions in which, in a few or in all ECG leads, an Osborn wave or distinct J-point-elevation may be observed.

Aged↗

Effect of GLG-V-13, a class III antiarrhythmic agent, on potassium currents in rabbit ventricular myocytes.

The effects of a new Class III antiarrhythmic drug, GLG-V-13, on the 4-aminopyridine sensitive transient outward current, on the inward rectifier potassium current, on the ATP sensitive potassium current and on the rapid and slow components of the delayed rectifier potassium current were studied in single rabbit ventricular myocytes using the whole-cell voltage-clamp technique. GLG-V-13 blocked the rapid component of the delayed rectifier potassium current in a dose-dependent manner, with an estimated EC50 value of 0.36 microM. At high concentration, the slow component of the delayed rectifier potassium current was also depressed by the drug (40% effect at 10 microM concentration). The transient outward current, the inward rectifier potassium current and the ATP sensitive potassium current were not influenced by GLG-V-13, even at 10 microM concentration. Thus, GLG-V-13 blocks predominantly the rapid component of the delayed rectifier potassium current which may play a significant role in the prolongation of repolarization by the drug in ventricular tissue.

4-Aminopyridine↗

[The principles of pharmacotherapy for arrhythmia at the turn of the millenium].

A review is presented at the main causes of the change in paradigm that has occurred in the past 10 years in antiarrhythmic pharmacotherapy. The new attitude is ascribed to (1) the advances made in the application of non-pharmacological therapeutic modalities (radiofrequency catheter ablation, implantable antiarrhythmic devices), (2) the modification of therapeutic practice in response to the results of large-scale prospective randomized clinical trials, and (3) the proper recognition and appropriate appreciation of the frequently life-threatening proarrhythmic action of antiarrhythmic drugs. The current state of knowledge is discussed as concerns the anti- and proarrhythmic effects of the drugs available at present, and also their safe clinical use.

Anti-Arrhythmia Agents↗

[Cardiac electrophysiological effect and clinical use of adenosine].

A review is provided of the present state of knowledge relating to the cardiac electrophysiological effects of adenosine at ion channel and clinical levels. It is emphasized that intravenous adenosine is highly effective in terminating sinus node, atrioventricular (AV) nodal and AV-reciprocating reentrant tachycardias. In the course of an account of the antiarrhythmic indications of adenosine therapy, the main aspects of the diagnostic use of the nucleoside are briefly discussed. It is pointed out that adenosine treatment may possibly be accompanied by the occurrence of atrial and ventricular proarrhythmias, for at pharmacological dose of 6-12 mg this endogenous cardioprotective and antiarrhythmic agent is not devoid of side-effects.

Adenosine↗

[Quinidine-induced syncope simulating transient cerebral ischemic attack].

A case of quinidine-induced syncope with prevailing neurological symptoms is reported in which the transient right-sided hemiparesis and fluctuating soporific state was induced by recurrent torsades de pointes ventricular tachycardias. In connection with this case, attention is paid to the difficulties of differential diagnosis and to the consideration of cardiac and metabolic disorders mimicking TIA or ischaemic stroke.

Aged↗

[Angina pectoris induced by pacemaker syndrome].

Pacemaker syndrome is caused primarily by the lack of atrial kick and by neurocardiogenic reflex mechanisms due to simultaneous atrial and ventricular contractions. The most common clinical symptoms are dyspnoe, hypotension, dizziness and syncopal attacks. A case report of a patient with pacemaker syndrome is presented, in which the main clinical manifestation was a recurrent chest pain. A VVI demand pacemaker was implanted because of sick sinus syndrome ten years ago and shortly afterwards anginal attacks of rest developed. Coronary angiography revealed a non-significant (25%) narrowing of the right coronary artery (RCA). Casual and long-term ambulatory blood pressure (ABPM) measurements elucidated that the patient occasionally has extremely low diastolic blood pressure. This later phenomenon was confirmed and refined by a "beat-to-beat" blood pressure measuring technique. The elimination of the pronounced "beat-to-beat" variability of arterial blood pressure and transient coronary hypoperfusion due to implantation of an AV sequential bifocal pacemaker resulted in a full disappearance of angina pectoris.

Angina Pectoris↗

Effects of orotic acid on ischaemic/reperfused myocardial function and glycogen content in isolated working rat hearts.

The present study was carried out to investigate the effect of orotic acid on ischaemic/reperfused myocardial function and cardiac glycogen content in isolated working rat hearts. In a preliminary series of studies, hearts isolated from male Wistar rats (300-350 g) were perfused with oxygenated Krebs-Henseleit buffer containing cumulative concentrations of orotic acid from 0.01 to 10.00 mg l-1. In the concentration range of 0.01-0.10 mg l-1, orotic acid significantly improved left ventricular function. Therefore, in the second series of studies, rats were treated intravenously with 0.01 mg kg-1 orotic acid for 4 days. Hearts were then isolated and subjected to 30 min of global no-flow ischaemia followed by 10 min of reperfusion. Orotic acid treatment significantly improved post-ischaemic myocardial function and increased pre-ischaemic and post-ischaemic glycogen content of the heart. We conclude that orotic acid improves ischaemic/reperfused cardiac performance and this effect may be based on the elevation of myocardial glycogen content.

Animals↗

Suppression of erythromycin-induced early afterdepolarizations and torsade de pointes ventricular tachycardia by mexiletine.

Erythromycin is a selective IKr-blocking, action potential duration (APD)-prolonging drug, which may induce early afterdepolarizations (EADs) and torsade de pointes ventricular tachycardia. The successful termination of an erythromycin-induced clinical torsades de pointes by the authors with mexiletine prompted them to investigate in vitro whether erythromycin is able to induce EADs in Purkinje fibers and, if so, whether EADs are suppressible or not by mexiletine. Electrically stimulated canine Purkinje fibers (n = 9) were superfused with erythromycin (200 mg/l) and action potentials were recorded by an intracellular microelectrode technique. Erythromycin induced a pronounced prolongation of APD and the appearance of EADs in all Purkinje preparations (9/9). After the addition of mexiletine (10 mM), a marked shortening of APD and the disappearance of EADs (7/9) were observed. Mexiletine, an inhibitor of the tetrodotoxin-sensitive window Na(+)-current, may prevent IKr-blocking drug-induced torsade de pointes ventricular tachycardia by abolishing APD prolongation and EADs.

Action Potentials↗

[Gallbladder hypomotility in diabetic polyneuropathy].

A study was made of the pathogenic role of gallbladder hypomotility, which is presumably responsible for the high incidence of gallstone disease in long-standing diabetes mellitus. The gallbladder motility of diabetic patients (n = 10) was measured by means of quantitative hepatobiliary scintigraphy, and the severity of concomitant autonomic and sensory polyneuropathy was determined. The presence of marked gallbladder hypomotility was proven, and a positive correlation was observed between the severity of autonomic neuropathy and the contractile disorder. In this group of diabetic patients, a hypaesthetic sensory polyneuropathy too was recognized, the degree of which exhibited a positive correlation with the autonomic neuropathy score. This study underlines the important role of the autonomic neural dysfunction in the development of gallbladder hypomotility accompanying long-term diabetes mellitus.

Diabetes Mellitus, Type 1↗

[Erythrocyte-induced "torsade de pointes" ventricular tachycardia].

A case of erythromycin-induced acquired long QT syndrome and "torsades de pointes" ventricular tachycardia is reported. The peculiar ventricular tachyarrhythmia was evoked by orally administered erythromycin (1.5 g/die) in the presence of diuretic (clopamide)-induced hypokalaemia. The pause-dependent "torsades de pointes" was preceded by prolonged QTU interval (560 ms), "particular bigeminy" and "short-long-short" RR interval sequence. The recurrent ventricular tachycardia causing syncopal attacks was abolished by the discontinuation of erythromycin treatment, K+/Mg(2+)-supplementation and oral mexiletine therapy. It is emphasized that the macrolide antibiotic/prokinetic erythromycin, applied in therapeutic dosages, blocks the rapidly activating delayed rectifier potassium current (IKr), and as such, prolongs ventricular repolarization and may be "torsadogenic".

Clopamide↗

[Increase of the QT interval dispersion in diabetes mellitus].

The QT dispersion, measured as the interlead variability of QT interval (QTd = QTmax-QTmin), reflects the spatial inhomogeneity of ventricular repolarization times. The authors studied QTd and heart rate-corrected QTd (QTc-d) in 81 patients with diabetes mellitus (IDDM: 39, NIDDM: 42) using Bazett's formula; 20 non-diabetic subjects acted as controls (means +/- SD). QTd (43 +/- 17 ms) and QT c-d (52 +/- 20 ms) were increased (p < 0.05) as compared to the control values (QTd = 32 +/- 17 and, QTc-d = 35 +/- 17 ms, respectively). A significant difference was also observed in QTc-d if the two diabetic groups were compared to the control separately (p < 0.05). Moreover, comparison of the diabetic groups (IDDM vs NIDDM) revealed that type I diabetes mellitus is accompanied by a more pronounced spatial dispersion of ventricular reporlarization (QTd = 49 +/- 16, and QTc-d = 59 +/- 19 ms) as compared to NIDDM (QTd = 38 +/- 16, QTc-d = 46 +/- 20 ms [p < 0.01]). The hypothesis that increased QTd/QTc-d is truly a predictive marker of sudden arrhythmic cardiac death in patients with diabetes mellitus needs further clinical investigation.

Adult↗

Complications of laparoscopic cholecystectomy in Hungary: a multicentre study of 13,833 patients.

OBJECTIVE: To report our countrywide experience of laparoscopic cholecystectomy with particular reference to complications. DESIGN: National multicentre retrospective study. SETTING: 71 university departments and public hospitals in Hungary. SUBJECTS AND INTERVENTIONS: 13,833 patients operated on between 1 January 1990 and 31 December 1993. Follow up by questionnaire. RESULTS: 732 patients (5.3%) required conversion to open cholecystectomy, urgently because of intraoperative complications in 204 (1.5%), electively for acute or chronic inflammation or obscure anatomy in 441 (3.2%), for unexpected findings in 72 (0.5%) and for technical problems in 15 (0.1%). There were postoperative complications in 598 (4.3%) but reoperation was indicated in only 154 patients (1.1%). There were bile duct injury in 81 (0.6%) and 199 bleeds (1.4%) which required conversion in 102 patients (0.7%) and reoperation in 38 (0.3%). 36 of the 181 postoperative recognized bile leaks required reoperation (20%). 19 patients died (0.1%). CONCLUSIONS: The morbidity and the mortality of laparoscopic cholecystectomy are better than after the open operation. The 2-6 times higher risk of bile duct injury mentioned in early studies was not confirmed.

Cholecystectomy, Laparoscopic↗

[Formulation and in vitro examination of furosemide-containing suppositories and preliminary experiences of their clinical use].

Rectal suppositories containing Furosemide (4-Chloro-N-furfuryl-5-sulfamoylanthranilic acid) and Furosemide Sodium were formulated with various suppository bases. The in vitro drug release of Massa Estarinum 299 proved to be the best from among the vehicles having various physical-chemical properties. The diuretic effect of the two suppositories was compared in a prospective, cross-over clinical trial including 8 patients. Both preparations have induced and increase of urine flow, which was comparable to the diuretic effect of the tablet. Thus the possibility of rectal use has been added to the modalities of therapeutic Furosemide administration.

Cross-Over Studies↗