Search PubMed⌕ Search

Biomedical subjects

J Kollár

Publications and source records attributed to J Kollár.

At least 19 recordsLinked to original sources
PubMed2003

Acetazolamide as a vasodilatory stimulus in cerebrovascular diseases and in conditions affecting the cerebral vasculature.

Pathologic processes affecting the brain vessels may damage cerebral vasodilatory capacity. Early detection of cerebral dysfunction plays an important role in the prevention of cerebrovascular diseases. In recent decades acetazolamide (AZ) has frequently been used for this purpose. In the present work the mechanism of action and the previous studies are reviewed. The authors conclude that AZ tests are useful in cerebrovascular research. Further investigations are recommended to prove how impaired reserve capacity and reactivity influence the stroke risk in patients and whether these tests may indicate therapeutic interventions.

Acetazolamide↗
PubMed2001

Parametrization of perovskite structures: an ab initio study.

An overview of the pressure, temperature and chemical composition dependence of the lattice distortion in orthorhombic ABO(3) perovskite structures is presented. Within the framework of the so-called global parametrization method (GPM) [Thomas (1998). Acta Cryst. B54, 585--599] an improved description for the position of the A cation in terms of the AO(12) and BO(6) polyhedral volume ratio is proposed. The relationship is derived from an extensive ab initio study based on the density functional theory. The applicability of the improved GPM in combination with ab initio total energy calculations in the prediction of changes in the structural distortion under increasing hydrostatic pressure is investigated. Test calculations are performed for the geophysically important magnesium silicate perovskite and the results are compared with the available theoretical and experimental data.

Journal Article↗
PubMed2001

Lack of gender difference in acetazolamide-induced cerebral vasomotor reactivity in patients suffering from type-1 diabetes mellitus.

The aim of the present work was to investigate the impact of gender on resting cerebral blood flow velocity and cerebrovascular reserve capacity among diabetic patients. Middle cerebral artery mean blood flow velocity (MCAV) was measured in 72 patients suffering from type 1 diabetes mellitus at rest and 5, 10, 15 and 20 min after intravenous administration of 1 g acetazolamide. Cerebrovascular reserve was calculated as the maximal percent increase in MCAV after acetazolamide. Resting MCAV and cerebrovascular reserve capacity were compared between males and females. Resting cerebral blood flow velocity was higher in diabetic females than in males (men, 55.0+/-17.0 cm/s; women, 64.4+/-12.6 cm/s, p=0.0094). Cerebrovascular reserve capacity was similar in diabetic women and men (men, 44.0%+/-18.6%; women, 52.6%+/-32.9%, p=0.17). Comparing MCAV and cerebrovascular reserve capacity among the diabetic subgroups with disease duration < or = 10 years and >10 years, we did not detect any differences between women and men. Duration of diabetes was an important factor in determining cerebrovascular reserve capacity in both sexes: long-term diabetic women and men showed lower CRC values than diabetics with < or = 10 years disease duration. Cerebrovascular reserve capacity is similar in diabetic women and men. Taking into consideration that cerebrovascular reserve is normally higher among women, our finding indicates a relatively more serious worsening of cerebral vasodilatory responses in women suffering from type 1 diabetes.

Acetazolamide↗
PubMed2001

Is every sharply defined, symmetrical, necrotic-demyelinating lesion in the corpus callosum an actual manifestation of Marchiafava-Bignami disease?

Neuroimaging of a 75-year-old lady demonstrated the characteristic pathological features of the Marchiafava-Bignami disease (MBD), which develops usually in chronic alcoholics. The onset of the neurological symptoms and signs were abrupt and similar to those seen in common ischemic vascular lesions. Our patient denied that she had consumed alcoholic beverage during her life. Laboratory results showed her liver enzymes were not elevated and a subsequent abdominal ultrasound examination revealed no liver pathology. The attack responded fairly well to anti-ischemic therapy and a complete recovery was observed within a week. In this sense, her pathology cannot be considered as a true MBD in spite of the presence of the CT and MRI findings of MBD. Our case seems to show that the CT and MRI findings in MBD are not specific because new imaging procedures reveal edematous, necrotic lesions that may have the appearance of MBD.

Aged↗
PubMed1999

[Immunohistologic determination of extracellular matrix components in granuloma annulare].

BACKGROUND: The histological diagnosis of granuloma annulare is based on assessment of a palisade-like granuloma and necrobiosis. The authors attempt to make a more accurate diagnosis of the disease based on immunohistological assessment of components of the extracellular matrix. METHODS AND RESULTS: In a group of 15 patients with granuloma annulare the authors assessed, using the immunoperoxidase method, collagens type I, III and V and fibronectin. An increased amount of collagens type III and V was found within the palisade-like granuloma and its neighbourhood resp. In the area of the necrobiosis the findings of the mentioned collagens depended on the degree of necrobiotic changes (12 of 15 patients). An increased occurrence of collagen type I was only indicated in the vicinity of granulomas or within the palisade-like granuloma in 7 of 15 patients. Larger amounts of fibronectin were found in the area of the necrobiosis and in the area of the granulomatous palisade-like infiltrate resp. (12 of 15 patients). CONCLUSIONS: In the author's opinion the higher incidence of collagens types III and V in the neighbourhood of the palisade-like granulomatous infiltrate and its size resp, as well as the finding of fibronectin in the area of necrobiosis and the granulomatous infiltrate justify the use of immunohistological assessment of the above constituents of the extracellular matrix as a supplementary examination in the diagnosis of the above disease.

Adult↗
PubMed1999

Screening of vascular cognitive impairment on a Hungarian cohort.

Cerebrovascular disease is a major public health problem in Eastern European countries. A Hungarian post-stroke population was examined to estimate the rate of dementia, the risk factors for cognitive impairment, and the applicability of a recently established Canadian diagnostic checklist in this cohort. Chronic cerebrovascular outpatients were screened for cognitive impairment with a combined checklist: the Diagnostic Checklist for Vascular Dementia established by the Consortium of Canadian Centres for Clinical Cognitive Research using the Mini Mental State Examination instead of the detailed neuropsychological part of the Checklist. Of the 247 consecutive patients at a cerebrovascular outpatient unit, 176 had cerebrovascular disorder diagnosed either by computed tomography (CT; n=126) or by the clinical signs. Of these, 15% were cognitively impaired and 5% fulfilled the criteria of dementia. The mean age of the patients with cognitive impairment was significantly higher than that of patients with normal cognition (68.2+/-10.2 and 60.5+/-10.5 years, P<0.001). The Barthel index was significantly lower in the cognitively affected group than in non-affected patients (92.4+/-16.0 and 97.1+/-8.7, P=0.027). Diabetes and more than two subcortical infarcts on CT or magnetic resonance imaging were more frequent in patients with cognitive loss (P=0.043 and P=0.013, respectively). Cognitive performance was also influenced by the level of education. Higher age, diabetes, motor deficits, and multiple subcortical infarcts are risk factors for cognitive impairment after stroke. The combined checklist appears to be a practical screening test for cognitive impairment in patients with chronic cerebrovascular diseases.

Age Distribution↗
PubMed1997

[Cerebral positron emission tomographic study in systemic lupus erythematosus].

The cerebral glucose metabolism in eight patients with systemic lupus erythematosus (SLE) and in five healthy controls were examined by positron emission tomography (PET) using 18-F-labeled deoxy-glucose (FDG) as tracer. One of the eight patients had no abnormality by magnetic resonance imaging (MRI), three of them had cerebral atrophy and four patients had multiple white matter hyperintensities and vascular infarcts in the striatum as assessed by MRI. With FDG-PET, inhomogeneous multifocal cerebral glucose hypometabolism was detected, more frequently in the temporal lobe of right hemisphere. The PET findings did not correlate always with the neurological symptoms. Abnormalities in brain metabolism can be detected more frequently by PET, than morphological changes by MRI, indicating the involvement of the central nervous system.

Adult↗
PubMed1997

[First Hungarian experiences with positron emission tomography (PET) studies. Members of the PET working group].

Diagnostic investigations commenced on the 28th of June 1994 in Hungary's and Central Europe's first PET Centre at the University Medical School of Debrecen. The Centre is equipped with a GE 4096 Plus whole body PET scanner. A metabolic tracer, 18F-deoxy-D-glucose (FDG), was used in the investigations. During the first 15 months 249 PET investigations were made in the Centre of which 242 were diagnostic and 7 normal subjects served as control for the patient studies with brain scans. The number of oncological indications (intra- and extracranial tumours, Hodgkin's lymphomas) was n = 105 (43.4% of the 242 diagnostic examinations), neurological investigations (without intracranial tumours) formed the dominant group (n = 117; 48.3%), whereas the number of cardiological indications was 20 (8.3%). The oncological studies included those of intracranial tumours (n = 76; 31.4%); thyroid tumours (n = 9; 3.7%); Hodgkin's lymphomas (n = 7; 2.9%) and other extracranial tumours (n = 13; 5.4%). The distribution of different neurological and psychiatric investigations was as follows: localization of focal epileptogen zone (n = 60; 24.8%); differential diagnosis of dementias (n = 30; 12.4%); exploration of cerebrovascular diseases (n = 10; 4.1%); and other neurological diseases (n = 17; 7.0%). The main objective of the cardiological PET investigations was the exploration of viable myocardium. The present paper overviews both the procedures (including administrative issues, as well) and the results of the first 249 FDG-PET investigations.

Aged↗
PubMed1997

[Angiographical evaluation of extracranial carotid artery: comparison between Japanese and Hungarian].

We investigated the cervical level of carotid bifurcation, diameter of common carotid artery (CCA) and internal carotid artery (ICA) in 147 Japanese patients (150 arteries, range of age 31-79) and in 490 Hungarian patients (517 arteries, range of age 12-77). The cervical level of carotid bifurcation was determined by comparison with cervical vertebra. The carotid bifurcation of Japanese was most frequent at the lower part of 3rd cervical vertebra but in Hungarian the bifurcation was most frequent at the middle part of 4th cervical vertebra. Japanese carotid bifurcation was high-positioned compared with Hungarian. The mean CCA diameter in Japanese was 7.47 mm in male and 7.07 mm in female, in Hungarian 9.24 mm in male and 7.80 mm in female. The mean ICA diameter in Japanese was 4.96 mm in male and 4.83 mm in female, in Hungarian 8.56 mm in male and 7.66 mm in female. CCA and ICA diameter were larger in male than in female. The diameter of CCA had a significantly positive correlation with age (p < 0.002) but ICA had no similar correlation.

Adolescent↗
PubMed1997

[Levels of Lp(a) and apolipoproteins in vegetarians and their informative value in hyperlipidemia].

BACKGROUND: An increased level of Lp(a) and unphysiological, even risk levels of apolipoproteins (apo) are currently considered to represent more significant markers of the premature development of atherosclerosis than that of increased serum lipids. AIM AND OBJECTIVES: The aim of our study was to detect the changes in Lp(a), apo A-I, apo A-II, apo B and lipids (TCH, TG, LDL-CH, HDL-CH, non HDL-CH) levels in 54 middle-aged vegetarians (V). METHODS: In addition to vegetarians, 40 persons, all middle-aged workers of a chemical firm with hyperlipidaemia B and C (HLP) were examined. The control group was constituted of 23 healthy people, normolipidaemics with common dietary patterns (K). Their age was mutually comparable within the examined groups. The apo A-I, apo A-II and Lp(a) levels were assessed by means of the radial immunodiffusion method, and apo B levels were detected by electroimmunoprecipitation method. RESULTS: The vegetarians yielded the lowest Lp(a) level, as well as an excellent lipid profile including apolipoproteins. The workers with HLP yielded significantly increased levels of apo B (p < 0.001), Lp(a) (p < 0.01), and values of the atherogenic index of apo B/apo A/I (p < 0.001) with simultaneous hypoapolipoproteinaemia apo A-I (p < 0.05) and apo A-II (p < 0.001). CONCLUSION: Physiological levels of lipids and apolipoproteins including the significantly lower levels of apo B, Lp(a) and levels of the index of apo B/apo A-I in persons with a high intake of fiber and minimal consumption of unsaturated fat give evidence of the decisive role of nutrition regarding the maintenance of optimal levels of lipids and lipoproteins and therefore represent the guarantee of protection from a premature development of atherosclerosis. (Tab. 1, Fig. 10, Ref. 11.)

Adult↗
PubMed1995

[Morphological differences in carotid angiograms and their relation to age].

The level of carotid bifurcation, frequency of the kinking of the internal carotid artery, correlation between the diameter of carotid arteries and the age of the Hungarians was examined. The cervical level of carotid bifurcation, diameter of extracranial carotid arteries, frequency of kinking of internal carotid arteries were measured on conventional carotid angiograms in 490 Hungarian patients (517 arteries, age range 12-77 yr). The cervical level of the carotid bifurcation was determined by comparison with cervical vertebra. The most frequent level of carotid bifurcation was found at the middle part of 4th cervical vertebra. The position shifted higher with ageing. The mean common carotid artery diameter was 9.24 +/- 1.58 mm in males and 7.80 +/- 1.10 mm in females. The mean internal carotid artery diameter was 8.56 +/- 1.84 in males and 7.66 +/- 1.39 in females. The mean external carotid artery diameter was 5.53 +/- 1.11 mm in males and 4.76 +/- 0.91 in females. The diameter of the common carotid artery has a significantly positive correlation with age (p < 0.05) but internal carotid artery and external carotid artery had no similar correlation. The kinking of internal carotid artery was observed frequently in patients who had higher level of carotid bifurcation.

Adolescent↗
PubMed1995

Are intra- and suprasellar masses detected by CT and MR really tumours?

The difficulties of differential diagnosis between intra- and suprasellar tumours resp. inflammatory processes are discussed, based on three personal cases. In all three computed tomography (CT) and magnetic resonance imaging (MR) had demonstrated a tumour, but the clinical signs with discrepancies between radiological and clinical findings were pointing to an inflammatory process. The correct diagnosis of an inflammation was achieved by co-operation between neurologist, neurosurgeon, otologist and ophthalmologist. An unnecessary neurosurgical operation was avoided and the patients were cured by otological intervention and antibiotic therapy.

Adult↗
PubMed1995

[Computer tomography in implantology].

During the planning of implantation the CT method helps in determining the location of the implant and aids in choosing the right implant. It provides the following measurable information about the jaw-bones: height and width; exact location of bone deficiencies; the orovestibular shape of the alveolar process; the course of the mandibular canal; the location of the mental foramen; the location and size of the canalis incisivus; the area of the nasal cavity and the maxillary sinus; the quality of the bones and the relationship between cortical and spongious bone. In comparison to the X-ray examinations possession of these informations increase significantly the safety of planning before surgery.

Dental Implantation↗
PubMed1994

[Ischemic cerebrovascular lesion caused by left atrial myxoma].

A case presentation is given of a 40 years old woman with acute ischemic cerebrovascular lesion in the territory of the left middle cerebral artery caused by embolization from a myxoma in the left atrium. The tumor was diagnosed by transthoracic echocardiography. Histological examination after cardiac surgery revealed a benignant myxoma. In the six-month-long postoperative follow up gradual improvement of the neurological signs was observed. The most important morphological and clinical characteristics of myxomas are summarized. The necessity of detailed cardiological examination of each young patient with stroke is emphasized.

Acute Disease↗