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Tibor Kovács

Publications and source records attributed to Tibor Kovács.

At least 19 recordsLinked to original sources
PubMed2006

[Multiple system atrophy: the beginning of a new era in the history of neurodegenerative diseases].

Multiple system atrophy (MSA) belongs to the neurodegenerative diseases of the nervous system, but it is different from them in many aspects: it has no familiar form and no genetic factor was identified in the pathomechanism. Its neuropathology is unique too, because oligodendroglial cells are harbouring the main pathological burden. It was described in MSA that there is no elective neuronal degeneration in neurodegenerative disorders: the glial cells show the same pathochemical and structural abnormalities as found in the neurones. The discovery of the glial cytoplasmic inclusions, as a pathognostic marker for MSA, has directed attention to the glial cells in other neurodegenerative disorders. As a result of this, there are several neurodegenerative diseases nowadays in which glial inclusions were described, similar to the neuronal inclusions in their structural and biochemical properties and some of them became the diagnostic marker of the disease. In our review we summarize the clinical features, the history and the neuropathology of MSA and we discuss its special features.

Humans↗
PubMed2006

[Aids-related toxoplasma-encephalitis presenting with acute psychotic episode].

The most frequent neurological manifestations of the Acquired Immunodeficiency Syndrome-(AIDS) are Cerebral Toxoplasmosis, Primary Central Nervous System Lymphoma (PCNSL), Progressive Multifocal Leukoencephalopathy (PML) and AIDS-encephalitis (AIDS-dementia complex, multinucleated giant cell encephalitis, HIV-encephalopathy). Neurological complications usually occur in the advanced stages of the disease, and they are uncommon in the beginning as presenting illness, but may result in life-threatening condition or in death. Rarely the disease presents as a neuropsychiatric illness in an undiagnosed AIDS patient, delaying a proper diagnosis. We present the case of a 34 years old patient treated for AIDS-related Toxoplasma-encephalitis in our department. His illness started as an acute psychosis followed by rapid mental and somatic decline, leading to death in three months. His HIV-seropositivity was not known at his admission, and the extraneural manifestations were slight. The diagnosis was established by serology, imaging methods and histopathological investigation. After presenting the medical history and results of autopsy studies of the patient we discuss the problems of the differential diagnosis, especially regarding the findings of the imaging methods.

AIDS-Related Opportunistic Infections↗
PubMed2006

Radon concentration in houses over a closed Hungarian uranium mine.

High radon concentration (average 410 kBq m-3) has been measured in a tunnel of a uranium mine, located 15-55 m below the village of Kovágószolos, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m-3. Significantly higher radon concentrations (average 667 Bq m-3) were measured in houses within +/-150 m from the surface projection of the mining tunnel +50 m, compared with the houses further than the 300-m belt (average 291 Bq m-3). The average radon concentration of the soil gas was 88.8 kBq m-3, the average radon exhalation was 71.4 Bq m-2 s-1 and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m-3) may influence the radon concentration of the houses over the mining tunnel.

Environmental Monitoring↗
PubMed2006

[Cytoreductive surgery and intraperitoneal hyperthermic chemoperfusion for peritoneal carcinomatosis caused by recurrent inflammatory myofibroblastic sarcoma: a case report and review of the literature].

Peritoneal carcinomatosis is a fatal diagnosis, associated with poor prognosis and quality of life. Survival is usually estimated in month. Traditionally surgery for peritoneal carcinomatosis was indicated only for palliative effort. Advances in tumour biology, cytoreductive surgery and pharmacology have improved the approach for this condition. An aggressive combined approach to peritoneal surface malignancy involves peritonectomy and intraperitoneal perioperative hyperthermic chemotherapy. Cytoreductive surgery reduces carcinomatosis to microscopic residual disease so that intraperitoneal hyperthermic chemotherapy is able to eradicate cancer. Hyperthermic chemotherapy enhances the cytotoxicity of the drugs and increases their penetration into the cancerous tissue. Careful patient selection is crucial for this multimodality approach. Quantitative prognostic indicators are useful in the assessment of outcome, like peritoneal cancer index and completeness of cytoreduction score. Cytoreductive surgery combined with intraperitoneal hyperthermic chemotherapy improves survival but is associated with significant morbidity and mortality. This review is based on a case report of a 22-year-old female patient who had peritoneal carcinomatosis of inflammatory myofibroblastic sarcoma and was treated by cytoreductive surgery and intraperitoneal hyperthermic chemotherapy at our department.

Adult↗
PubMed2005

Similarities between CSF-brain extracellular transfer and neurofibrillary tangle invasion in Alzheimer's disease.

Using the in vivo enzyme protection-enzyme inhibition method, we visualized the distribution of the intraventricularly and cisternally (cisterna magna) injected ambenonium chloride (Am) bound reversibly to the extracellular acetylcholinesterase enzyme (AChE) in the rabbit brain in order to describe the extracellular flow pathways from the cerebrospinal fluid (CSF). We found that the distribution of Am-protected AChE (indicating the Am itself) is similar to tracers having no intracerebral binding sites. The topographical distribution after both ways of application indicates a preferential penetration of Am into the limbic structures of the cerebral hemispheres in a predictable topographic sequence starting from the corticoid areas, allo- and periallo cortices followed by the mesocortical regions and then, in a limited extent, to the isocortex. The lentiform nuclei and the central part of diencephalic halves are inaccessible to Am. The hierarchic order in the sequence of diffusion from the CSF into the hemispheric subpial regions and the distribution pattern of Am resemble the stereotypic topographic expansion pattern and the predominantly limbic distribution of neurofibrillary tangles (NFTs) in Alzheimer's disease and related conditions.

Acetylcholinesterase↗
PubMed2005

[Clinico-pathology and differential diagnosis of Binswanger's disease].

Pathologically, Binswanger's disease is subcortical periventricular leucoencephalopathy sparing the U fibers. Clinically it is characterised by executive dysfunction, gait problems, urinary incontinence, pseudobulbar palsy, mood disturbances and dementia. The pathomechanism of Binswanger's disease is unclear. It is hypothesized that it results from an ischemic-hypoxic injury of the periventricular white matter, which, in turn, can be caused by a sclerotic elongation of the medullary arteries, widening of the perivascular spaces or decreased brain perfusion due to hypotension or heart disease. The symptoms of Binswanger's disease frequently overlap with those of normal pressure hydrocephalus, vascular parkinsonism and Alzheimer's disease. A diagnostic criterion of Binswanger's disease is radiologically demonstrated leukoaraiosis, which, on the other hand, is not equivalent with Binswanger's disease. A good clinical response after lumbar puncture or shunt implantation might lead to confusion with normal pressure hydrocephalus, which further complicates the clinical diagnosis. It is likely that among the above mentioned disorders there are a number of transitional forms and overlaps, which might be explained by the common pathomechanism of disturbance in cerebrospinal fluid circulation.

Adult↗
PubMed2005

Does testis weight decline towards the Subarctic? A case study on the common frog, Rana temporaria.

Interpopulation comparisons of variation in resource availability and in allocation patterns along altitudinal and latitudinal gradients allow insights into the mechanisms shaping the life history of animals. Patterns of between-population differences in female life history traits have been studied intensively across a wide range of taxa, but similar investigations in males have remained scarce. To study if testis weight-a measure of reproductive investment-varies on a geographical scale in anurans, we focussed on the variation in relative testis weight (RelTW) and asymmetry in 22 populations of the common frog Rana temporaria along a 1,600-km latitudinal transect across the Scandinavian peninsula. We found that RelTW decreased towards the north. Body mass and body length both had independent positive effects on testes mass. We found evidence for directional asymmetry (DA) in testis weight with the right testis being larger than the left. The level of DA in testis weight was not related to latitude, but both body mass and testes mass had independent positive effects on asymmetry. We discuss the northwards decrease in RelTW in terms of a decreased reproductive investment as a possible consequence of harsher environmental conditions, and perhaps also, weaker sexual selection in the north than in the south.

Animals↗
PubMed2005

[Clinical features of corticobasal degeneration].

Corticobasal degeneration was described in 1968 by Rebeiz, Kolodny and Richardson, who characterized the disease as a syndrome of asymmetric akinesis and rigidity, dystonia of the upper limb, apraxia, myoclonus and dementia. Atrophy of the frontal and parietal lobe, neuronal loss, gliosis and achromatic neurones (and nowadays astrocytic plaques) are the characteristic pathological features of the disease. Corticobasal degeneration is a rare or a rarely recognized disease and it is frequently misdiagnosed as Parkinson's disease. According to the Lang's criteria, corticobasal degeneration can be diagnosed in the presence of rigidity and one cortical symptom (apraxia, cortical sensory loss, alien hand) or in a patient with rigidity, dystonia and focal reflex myoclonus. Exclusion criteria are early dementia (as in primary degenerative dementias), early vertical gaze problems (as in progressive supranuclear palsy), resting tremor and good, sustained therapeutic response to levodopa (as in Parkinson's disease), severe autonomic problems (as in multiple system atrophy) and any pathology on imaging studies which might explain the clinical symptoms. It should be mentioned, that recently early dementia is recognized as an initial symptom of corticobasal degeneration. The authors present a case and review the literature to call attention to this disorder.

Aged↗
PubMed2005

[The similarities between the mechanism of wound healing and tumor development--literature review on the occasion of a patient with colonic adenocarcinoma metastasis in a dog-bite wound].

For more than a century, the role of wound healing in the growth of tumours has been implied based on observations in experimental and clinical studies. In the recent 10-15 years processes such as cell adhesion, angiogenesis, metastatic cascade and growth factors (fe: EGF, TGF-alpha, TGF-beta, IGF-1, IGF-II, PDGF) have been identified to play key roles in different stages of wound healing as well as in tumor progression. Experimental and clinical studies have established that wound healing creates a suitable environment favouring tumour growth and metastatic potential. Based on these observations, the clinical relevance of surgical procedures comes up, may playing a role in tumor recurrence after primary resection for cancer. This makes the opportunity of the development of completely new targeted approaches (antiangiogenic therapy, dormancy therapy) for the treatment of cancer. This review article is based on a case report of a 63-year-old female patient who had colonic adenocarcinoma metastasis of the hand after biting by a dog.

Adenocarcinoma↗
PubMed2005

Influence of thymidylate synthase gene polymorphisms on the survival of colorectal cancer patients receiving adjuvant 5-fluorouracil.

The present study aimed to prospectively investigate the influence of thymidylate synthase (TS) polymorphisms (5'-TSER, 3'-TSUTR) on the disease-free survival (DFS) and overall survival (OS) of patients with colorectal cancer (CRC) who were treated with adjuvant 5-fluorouracil (5-FU) therapy. Patients were followed up for 19+/-14 months (median+/-SD). TS genotypes were determined from the peripheral blood mononuclear cells of 166 patients by polymerase chain reaction-polyacrylamide gel electrophoresis and restriction fragment length polymorphism methods. 5'-TSER 3R homozygotes showed significantly longer DFS (P = 0.048) and OS (P = 0.009). The 5'-TSER and 3'-TSUTR genotype combination groups showed a significant difference for DFS (P = 0.039) and OS (P = 0.029). Significantly better DFS (P = 0.049) and OS (P = 0.043) were observed for 6 bp/6 bp genotypes in 5'-TSER heterozygotes (n = 80). Based on this, and on hazard ratios obtained by Cox regression analysis of the DFS of genotype-combinations, the patients were classified as belonging to prognostic groups A and B. The DFS and OS of these two groups showed a highly significant difference (P = 0.002 and 0.001). In the multivariate Cox regression model, beside tumour location, the prognostic classification (groups A and B) proved to be an independent prognostic factor. Our data suggest that those TS genotypes and their combinations (group A: 3R/3R with any 3'-TSUTR genotype and 2R/3R with 6 bp/6 bp), which have been reported earlier as having high TS expression, predict significantly longer DFS and OS. We found that a combination of germline TS polymorphisms is an independent prognostic marker in selecting CRC patients with worse prognosis, and it may be worthwhile to examine whether these patients would benefit from an alternative therapy.

3' Untranslated Regions↗
PubMed2005

[Experience with radiofrequency ablation in the treatment of unresectable pelvic recurrence of rectal cancer].

More than half of colorectal cancers are located in the rectum, and the number of such cancers is increasing. In Hungary colorectal cancers are diagnosed predominantly in advanced stages. In the last five years 736 patients with colorectal cancer were operated on at our Department, with the following stage distribution: Dukes A 10%, BI 10%, B2 31%, C 36% and D 13%. The local recurrence rate is decreasing since the introduction of total mesorectal excision and preoperative radiation. Effective treatment options are however poor for unresectable pelvic recurrences. Chemo- and radiotherapy have severe limitations in this advanced stage cancer. In recent years there are a few publications on the minimal-invasive radiofrequency tumour ablation (RFTA) technique, which is an effective treatment for primary and metastatic liver carcinomas and is a new palliative for the local treatment of pelvic recurrence. The aim of this study was to assess the response to treatment using ultrasound-guided radiofrequency ablation in two patients with unresectable pelvic recurrent rectal cancer.

Aged↗
PubMed2004

[Prognosis and classification of hypertensive striatocapsular haemorrhages].

INTRODUCTION: Nontraumatic intracerebral haemorrhage accounts for 10 to 15% of all cases of stroke. PATIENTS AND METHOD: In our study hypertensive striatocapsular haemorrhages were divided into six types on the basis of arterial territories: posterolateral, lateral, posteromedial, middle, anterior and massive (where the origin of the hemorrhage can not be defined due to the extensive damage of the striatocapsular region) type. We analysed laboratory data, clinical presentations and risk factors as alcoholism, smoking and hypertension of 111 cases. The size of the hematoma, midline shift and severity of ventricular propagation were measured on the acute CT-scan. The effect on the 30-day clinical outcome of these parameters were examined. RESULTS AND CONCLUSION: According to our results, the most important risk factor of hypertensive intracerebral haemorrhage was chronic alcoholism. Blood cholesterol, triglyceride levels and coagulation status had no effect on the prognosis, but high blood glucose levels significantly worsen the clinical outcome. In our study, lateral striatocapsular haemorrhage was the most common while middle one was the least common type. The overall mortality is 42%, but differs by the type. The 30-day outcome significantly depends on the type of the haemorrhage, the initial level of consciousness, the size of the haematoma, the severity of ventricular propagation, the midline shift and the blood glucose levels. The clinical outcome proved to be the best in the anterior type, good in the posteromedial and lateral types. The prognosis of the massive type is poor. In our study, the classes and the mortality of the striatocapsular haemorrhages was different from the literature data. The higher mortality in our cohort could be due to the longer follow-up and the severe accompanying diseases of our patients.

Adult↗
PubMed2004

Tail loss and thermoregulation in the common lizard Zootoca vivipara.

Tail autotomy in lizards is an adaptive strategy that has evolved to reduce the risk of predation. Since tail loss reduces body mass and moving ability-which in turn are expected to influence thermal balance-there is potential for a trade-off between tail autotomy and thermoregulation. To test this hypothesis, we studied a common lizard (Zootoca vivipara) population at high latitude, inhabiting a high-cost thermal environment. Z. vivipara is a small, non-territorial lizard known as a very accurate thermoregulator. We made two predictions: (1) the reduced body weight due to tail loss results in faster heating rate (a benefit), and (2) the reduction in locomotor ability after tail loss induces a shift to the use of thermally poorer microhabitats (a cost), thus decreasing the field body temperatures of active lizards. We did not find any effect of tail loss on heating rate in laboratory experiments conducted under different thermal conditions. Likewise, no significant relationship between tail condition and field body temperatures, or between tail condition and thermal microhabitat use, were detected. Thus, our results suggest that tail autotomy does not influence the accuracy of thermoregulation in small-bodied lizards.

Animals↗
PubMed2004

Mechanisms of olfactory dysfunction in aging and neurodegenerative disorders.

Although olfaction is the primal sense in animals, its importance in humans is underappreciated. Extensive literature demonstrates that aging is accompanied by olfactory loss and hyposmia/anosmia which is also a feature of several neurodegenerative disorders. Alzheimer's and Parkinson's diseases are characterized by severe olfactory deficits, while problems of olfactory discrimination are less prominent features in several other disorders. Olfactory loss is accompanied by structural abnormalities of the olfactory epithelium, the olfactory bulb and the central olfactory cortices. This review summarizes our present knowledge about the pathological changes in the olfactory system during aging and in various neurodegenerative diseases.

Aging↗
PubMed2004

[Change of attitude in the surgical treatment of lung metastases].

There has been no major change in surgical technique of lung metastasectomy till the last decades. In the latest years the variety of diagnostic tools and methods grew significantly. There are more chemotherapy possibilities and more palliative surgical techniques (VATS, ITP, RFTA) to treat certain types of lung metastases. Based on data of the International Registry of Lung Metastases the most important prognostic factor for metastasectomy is how radical the procedure was (clear resection margin). The more aggressive approach (even pneumonectomy for R0 resection) is becoming more popular.

Humans↗