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Biomedical subjects

A Kollár

Publications and source records attributed to A Kollár.

At least 19 recordsLinked to original sources
PubMed2005

Bilateral axillobrachial and external carotid artery manifestation of giant cell arteritis: important role of color duplex ultrasonography in the diagnosis.

A 76-year-old man was admitted to our hospital with vertigo. Previously he had been extensively examined because of an increased erythrocyte sedimentation rate without any clinical symptoms. Physical examination revealed 60 mmHg blood pressure difference between the two arms. Color duplex ultrasound examination revealed bilateral extreme narrowing of the external carotid and axillobrachial artery with a dark, hypo-echoic halo around the lumen. This condition was recognized as a specific sign for giant cell arteritis (GCA), described originally in cases of temporal arteritis. The diagnosis was confirmed by biopsy of the temporal artery. In contrast to the typical cranial form of GCA -- our patient showed an unusual, bilateral large-vessel manifestation. The diagnosis was based on ultrasound images rather than on symptoms that characterize the well-known temporal form. This observation emphasizes the role of color duplex ultrasonography in the diagnosis and follow-up of GCA.

Aged↗
PubMed1998

3,3',5-Triiodothyronine (T3) uptake and expression of thyroid hormone receptors during the adaptation to hypothyroidism of the brain of chicken.

Thyroid hormone action in the brain is strictly regulated, since these hormones play a crucial role in the development and physiological functioning of the central nervous system. Hormone kinetics and molecular events at the nuclear receptor level during the adaptation of the brain of chicken to hypothyroidism were simultaneously investigated. Data obtained by Oldendorff's 'single-pass' technique showed a significantly higher labelled 3,3'5-triiodothyronine (125I-T3) uptake into the brain of surgically thyroidectomized (TX) 2-week-old broilers after 1 week of surgery in comparison to sham-operated (SH) and t3 supplemented (TX + T3) controls in the 10th second after the bolus injection. Telencephalons showed the highest, while cerebellum the lowest uptake intensity in all groups. In a similar arrangement of experiments the expression of the TR alpha- and TR beta nuclear thyroid receptors in the telencephalon of TX and control chickens was investigated by a semiquantitative RT-PCR-based approach for beta-actin, then amplified for thyroid receptors. The level of both the TR alpha and TR beta coding mRNA was elevated in hypothyroidism. In conclusion, the presented hormone kinetics and TR expression data provide further details of the cellular and molecular events occurring during the adaptation to hypothyroidism of the brain of chicken.

Animals↗
PubMed1994

Evidence that ORF 1 and 2 are the only virus-encoded replicase genes of cymbidium ringspot tombusvirus.

The 33-kDa and its 92-kDa readthrough protein genes (open reading frames (ORFs) 1 and 2) of cymbidium ringspot tombusvirus (CyRSV) were introduced into Nicotiana benthamiana plants. Protoplasts derived from transgenic plants expressing the first two ORFs were inoculated with in vitro transcripts of defective interfering (DI) RNA. The efficient replication of input DI RNA, which is incapable of autonomous replication, confirmed the biological activity of the expressed viral replicase. In addition, in vitro transcripts of a genomic RNA deletion mutant clone encoding only ORFs 1 and 2 were able to replicate on their own and could support the replication of CyRSV DI RNAs in N. benthamiana protoplasts.

Amino Acid Sequence↗
PubMed1993

[Pathogenic role of a pacemaker in occult infection].

A case of seronegative pacemaker lead infection is presented. The diagnosis based on patient history and echocardiography was proved by removing the infected leads from the beating heart through surgery.

Echocardiography↗
PubMed1993

Functional analysis of cymbidium ringspot virus genome.

Genomic RNA of cymbidium ringspot tombusvirus (CyRSV) contains five large open reading frames (ORFs). The two 5' proximal ORFs encode proteins of 33 and 92 kDa and the three 3' proximal ORFs encode proteins of 41, 22, and 19 kDa. In addition, a small reading frame encoding a protein of 4 kDa was recently observed by computer analysis of the 3' nontranslated region of CyRSV and other tombusvirus RNAs (ORF 6). The function of putative gene products was investigated with the use of several mutants. Mutants in ORFs 1 and 2 were not viable indicating that both 33- and 92-kDa proteins are required for replication. Deletion of a large portion of the coat protein gene, encoding a 41-kDa protein, did not prevent replication of viral RNA and cell-to-cell movement, but interfered severely with long-distance translocation. No virus particles or viral RNA could be detected in inoculated or upper leaves of plants inoculated with transcripts obtained from mutants not expressing the 22-kDa protein. However, replication and encapsidation occurred normally in inoculated protoplasts indicating that this gene product is a transport protein. Conversely, no role could be assigned to putative gene products of ORF5 (19-kDa protein) and ORF6. It was also shown that factors other than gene expression can influence the replication of RNA mutants, probably due to instability of RNA molecules.

Base Sequence↗
PubMed1993

Efficient pathogen-derived resistance induced by integrated potato virus Y coat protein gene in tobacco.

The coat protein (CP) gene from potato virus Y (Hungarian isolate, PVY-H) was engineered into Agrobacterium tumefaciens binary vector for expression in different tobacco lines. Three different Nicotiana tabacum breeding lines were transformed and the integration of the CP gene was confirmed by PCR technique using genomic DNA preparations. The transcription and expression of the integrated CP gene was detected by Northern and Western blots. Pathogen-derived resistance was demonstrated by inoculation of the R1 progeny of the transformed lines with purified PVY-H. The efficiency of protection varied between different transgenic plants ranging from almost complete to no protection. Five CP expressing tobacco lines were resistant to challenge infection with PVY-H as indicated by attenuation or absence of symptom development associated with reduction or lack of detectable virus accumulation. Data from Western blots showed that there is no correlation between the level of the expressed CP and the extent of protection. This suggests that the mechanism of the observed resistance is independent of the level of CP accumulation in the transgenic tobacco plants.

Agrobacterium tumefaciens↗
PubMed1992

[Combined coronary artery and heart valve surgery at the Clinic for Cardiovascular Surgery (1979-1990)].

As a result of increasing mean age of patient undergoing open heart surgery more and more combined valve and coronary surgery cases are performed. The operative risk of combined procedure is higher than that of valve replacement or coronary bypass grafting alone. In case of aortic valve disease the operation reduces the workload of the left ventricle thus decreasing the oxygen demand of the myocardium. In pure mitral valve stenosis as a consequence of valve replacement the left ventricular preload increases and coexisting coronary artery disease is of greater importance than in the other case. Since 1979 until the end of 1990 there were 146 combined operations performed in the Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest. The operative results and theoretical considerations are discussed.

Cardiac Surgical Procedures↗
PubMed1992

[Coronary surgery at the Cardiovascular Surgical Clinic (1976-1990)].

In the Cardiovascular Surgical Clinic of the Semmelweis Medical University of Budapest the first coronary artery bypass grafting (CABG) procedure was performed in 1975. Since that time coronary artery surgery has become a routine everyday practice representing more than half of the total workload of adult cardiac surgery. The analysis of 1347 operations performed between 1976-1990 on patients with coronary heart disease showed the followings: the first few years--so called learning curve of CABG operations is characterised by high mortality. With passing time the number of cases performed each year increased rapidly and the surgical technique has improved too. At the same time the operative mortality figures showed decreasing tendency--it was 2.1% for the last 609 cases. All observed parameters showed some progress: in 1990 the average number of grafts per patient was 3.09, internal mammary artery usage 15 percent and the mean aortic cross clamp time per anastomosis 24.5 minutes. Complete myocardial revascularisation is the key point of coronary artery surgery. In order to achieve this target in all operated cases further technical improvement is necessary.

Coronary Artery Bypass↗
PubMed1992

[Development and results of valve replacement surgery at the Városmajor Clinic 1976-1990 (retorospective clinical analysis)].

In Hungary valve replacement is still a major indication for heart surgery in adults. In the Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest from 1976 to 1990 2435 patients were operated for valve disease. Majority of the cases had single (aortic n = 856, mitral n = 912) or double (aortic + mitral n = 513) valve replacement. Over this 15 years period there have been many alterations in patients characteristics and surgical technique as well. In spite of the increasing mean age of patients the operative mortality has decreased (in the last 5 years period it was 2.7%, 5.5% and 7.9% in the three groups respectively). At the same time the number of patients requiring valve re-replacement or combined valve + coronary procedure has increased. The use of bioprosthetic valves has fallen below 10 percent from the 60--80 percent observed between 1976--1980. The analysis showes excellent surgical results in the field of valve replacement in Hungary.

Cardiac Surgical Procedures↗
PubMed1992

[The place and role of coronary endarterectomy in the management of ischemic heart disease].

Coronary endarterectomy is one of the oldest operation performed on the coronary arteries. In the case of multivessel coronary artery disease it is an alternative method to achieve complete myocardial revascularisation however it increases both perioperative infarction rate and mortality. Sometimes it is undoubtedly the only chance of the patient apart from heart transplantation. Since 1983 when the first coronary endarterectomy was performed in the Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest, until the end of 1990 the procedure has been used in 97 patients on 119 coronary artery segments. A new surgical technique of coronary endarterectomy is described, a detailed analysis of the cases is presented and the results are discussed.

Anastomosis, Surgical↗
PubMed1991

[Development of Hungarian heart surgery, its results and current state in the light of the 40-year activity of the "Városmajor Clinic". Review of 40 years of surgery in Hungary, analysis of mortality data].

Forty years have passed since the first heart surgical department was founded in Hungary. In the University Hospital (present name: Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest) the Hungarian "pioneers" had produced internationally respected results in the mid-fiftieth with the operation of closed mitral commissurotomy. However the technique of cardiopulmonary bypass was first introduced into the clinical practice quite early, it has not become a routine everyday procedure until the late seventies. Over the last 15 years period the number of open heart surgical cases has increased permanently, and the operative mortality decreased at the same time. The analysis of 4743 cases performed between 1976 and 1990 showed improving results both in the field of valve replacement and coronary artery surgery and the recent operative mortality figures (3-5% in different groups) are comparable to other European centers.

Cardiac Surgical Procedures↗
PubMed1991

Dopamine-induced aggravation of myocardial ischaemia in the paced heart: cardiosurgical perspectives.

The action of dopamine on the blood supply to acutely ischemic cardiac areas was investigated at arbitrarily selected, fixed heart rates. The A-V node of open chest dogs was crushed and the ventricles were paced between 30 and 220 beats per minute (bpm). Ischemic blood supply was assessed by computer-aided infrared thermography. It was found that the ischemic (collateral-dependent) blood flow paralleled overall myocardial blood supply (coronary sinus outflow) and was directly related to heart rate between 30 and 100-140 bpm; above this frequency it decreased moderately. Dopamine (10 micrograms/kg i.v.) elicited a marked increase of ischemic flow in the heart paced at 60 bpm, whereas the drug action was characterized by a long-lasting flow decrease (preceded by a slight dilation) at 200 bpm. It was concluded that the treatment of the tachycardic heart with dopamine, as it frequently occurs in postbypass cardiac and coronary surgery, may place the non-completely revascularized myocardium at risk.

Animals↗
PubMed1990

[Auditory function in children and adolescents with diabetes mellitus].

The authors examined by audiometry 49 diabetics aged 3-18 years. Of these 47 patients aged 6-18 years (23 girls and 24 boys) were evaluated. A hearing disorder was found in four children. In one instance a conduction disorder after repeated otitis media was involved. In three children, i.e. 6.4%, perception hypacusia was found (once bilateral, twice unilateral). Based on the mentioned findings, the authors recommended systematic monitoring of the auditory function of all diabetic children.

Adolescent↗
PubMed1989

The dopamine-induced coronary vasoconstrictor response is potentiated by adenosine administration in the dog heart.

The ineffectiveness of beta-adrenergic blockade in abolishing adenosine-induced coronary vasodilation was utilized to demonstrate that dopamine (DA) is capable of eliciting very strong coronary vasoconstrictor actions in vivo. In 2 separate groups of dogs anesthetized with pentobarbital, responses to DA were assessed either by flowmeter recordings or by computer-aided infrared thermography, which senses coronary blood flow-dependent heat emission from the epicardium. In untreated controls, submaximal DA infusions (16 micrograms.kg-1.min-1 iv) elicited a coronary vasodilator response. The thermographic equivalent of this hemodynamic action was an increased epicardial temperature. Pretreatment with oxprenolol (0.5 mg.kg-1 iv) preserved both basic heart activity and cardiac heat emission at levels which were comparable to the control state, but prevented DA mediated excitation of cardiac and coronary beta-adrenoceptors. In this state, DA infusion constricted the coronary arteries and tended to decrease heart emission. However, both types of effects were moderate, and only the hemodynamic effect was statistically significant. If DA was given after the coronary bed had been dilated submaximally by adenosine (30 micrograms.kg-1.min-1 infused into the left heart), the flow-reducing effect of DA became a dramatic phenomenon, and the DA-induced epicardial cooling was significantly potentiated. The results show that after eliminating conventional beta-effects, DA affects the coronary arteries through vasoconstrictor mechanisms. This finding suggests that the DA-induced constriction is limited in undilated coronary arteries by the metabolic autoregulatory capacity of the vessels.

Adenosine↗
PubMed1989

[Indirect laryngoscopy].

The inside of the larynx during an indirect laryngoscopy canbe better inspected by inspiratory phonation. The author has used a simple maneouvre in patients where the inspection of the larynx is difficult.

Humans↗
PubMed1989

[Intranasal meningoceles].

The authors present a case of intranasal meningocele in 38-year-old patient. Clinical picture, diagnostics, treatment and postoperative course are described.

Adult↗
PubMed1987

[Does optokinetic stimulation modify directional hearing?].

The directional hearing of 20 healthy test persons, all with normal hearing abilities, was tested using a special self constructed equipment. Under the repeated influence of an optokinetic stimulation (rotating light beams on a semicircular screen in a completely darkened room) no statistically significant deviation of the directional hearing reactions could be detected.

Adolescent↗