Search PubMed⌕ Search

Biomedical subjects

L Csiba

Publications and source records attributed to L Csiba.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cerebrovascular reactivity measured by transcranial Doppler in migraine.

Changes in the diameter of intracranial arteries might have a major role in the pathophysiology of migraine. Though several studies have found alterations in velocity of blood flow and in cerebral vasomotor reactivity of intracranial arteries in migraineurs in headache-free periods, as well as during migraine attacks, the results are inconclusive. To determine if intracranial hemodynamic characteristics of patients with migraine differ from those of controls, we measured baseline velocity of blood flow by transcranial Doppler in the middle cerebral arteries in headache-free periods in 51 migraine patients and in 101 age-matched controls. Cerebrovascular reactivity was measured after intravenous administration of acetazolamide in 12 migrainous patients and in 19 controls. Baseline mean velocity was significantly higher in the migraine group (70 versus 65 and 72 versus 65 cm/s with P = 0.02 and P = 0.0007 on the left and right sides, respectively). The difference stayed significant during acetazolamide stimulation, but the course of response did not differ between controls and migraineurs. Despite statistical significance, absolute differences were small. Therefore, middle cerebral artery velocity measurements and the acetazolamide test are not useful for the diagnosis of migraine in the interictal period.

Acetazolamide↗
PubMed1995

[Importance of cerebrovascular reactivity testing in diabetes mellitus].

Diabetes mellitus results in macro- and microangiopathies. Early diagnosis and preventive treatment of the cerebral vessel complications may influence the prognosis of the disease. The aim of the present work is to summarize the recent results of the cerebral hemodynamic studies in diabetics. A suitable, non-invasive screening method for diagnosis of the altered cerebral arteriolar function is discussed.

Cerebrovascular Circulation↗
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

[Clinical and biochemical parameters of patients with vascular stenosis in the lower extremities in the stage of intermittent claudication].

Clinical and biochemical parameters obtained by complex investigation of 100 patients suffering from intermittent claudication are presented by the authors. After taking the family and case history, we examined the patients and took laboratory tests including several lipid components, blood clotting factors and parameters influencing blood viscosity. The severity of peripheral vascular disease was defined by ankle/arm ratio, carotid arteries were studied by duplex sonography, coronary circulation was examined by ECG, exercise ECG and Thallium-201 isotopic myocardium scintigraphy. In conjunction with lower extremity vascular disease internal carotid stenosis was diagnosed in 62% and coronary stenosis in 52% of cases examined. In 35% all three regions were affected. The degree of carotid stenosis showed a strong correlation to the severity of the claudication, while in case of the coronary disease there was no connection proved, in spite of its high prevalence. Among the risk factors smoking was present in 89%, hypercholesterolaemia in 84%, hypertension in 54%, diabetes mellitus in 13%, impaired glucose tolerance in 42% and positive family history in 39% of cases. Smoking and accumulation of the risk factors showed correlation to the severity of the lower extremity vessel stenosis, while hypertension and carbohydrate metabolism disturbances showed significant correlations to the degree of carotid stenosis. From different lipid parameters only the cholesterol/HDL-cholesterol ratio showed significant correlation to the severity of the arteriosclerosis. The authors refer to intermittent claudication as the risk factor for carotid and coronary disease. They suggest the assessment of the cerebrovascular and cardiac risk in the patients. This way the optimal order of operative and/or non-operative therapy can be realized.

Adult↗
PubMed1994

Acute brain swelling in cerebral embolization model of rats. II: Biochemical study.

To investigate the mechanism of acute brain swelling after cerebral embolism in rats, the authors evaluated the regional changes in tissue pH, ATP, blood-brain barrier function, and water content. The deep cerebrum--thalamus, hypothalamus, and hippocampus--had alkaline change in tissue pH accompanied with the disruption of the blood-brain barrier, decrease of ATP, and increase of water content. The cortex and the caudate putamen, on the other hand, did not show edema though acidic change and ATP decrease were seen. These results suggest that an early vasogenic edema in the deep cerebrum is a main factor for evolving acute brain swelling in this embolization model of rats.

Acute Disease↗
PubMed1994

A simple technique for the estimation of regional blood content in brain.

A simple and inexpensive technique is described for the assessment of regional cerebral blood volume (CBV) using a color reaction based on the pseudoperoxidase activity of hemoglobin. Cryostat sections are placed on a commercially available reagent strip originally designed for quantitative estimation of blood content in urine. After melting of the brain section, a blue color reaction appears which is darker in areas with higher hemoglobin content. The image is analyzed by a computerized image-processing system and evaluated by standards prepared from brain homogenate with different hemoglobin content. From the optical density data, regional CBV is calculated with correction for the difference between microvascular and large vessel hematocrit. The method was validated by a radiolabel procedure. Values of regional CBV are reported in gray matter areas of control rabbits and in brains embolized by autologous clot. This simple inexpensive technique is a useful supplementary tool in multiparametric metabolic studies.

Animals↗
PubMed1993

Spatial and temporal changes in tissue pH and ATP distribution in a new model of reversible focal forebrain ischemia in the rat.

The effects of reversible middle cerebral artery occlusion on regional pH and ATP distribution were studied in a new stroke model in rats by a planimetric method. Thirty minutes of ischemia was followed by 2, 4 and 24 hours of reperfusion. Ischemia resulted in acidosis and ATP depletion. In some areas tissue pH reached the threshold of the umbelliferone method (about pH 6.0). Areas with ATP depletion were significantly smaller than regions of pH alteration not only at the end of ischemia but during the first 4 hours of recirculation as well. By 4 hours of reperfusion large areas with altered pH were associated with ATP depletion in smaller regions, mostly in the hippocampus and the frontal cortex. The areas of ATP depletion were acidic initially, but by 4 hours alkaline pH could also be detected. Twenty four hours after ischemia alkaline areas (pH > 7.4) were found with ATP depletion, suggesting irreversible tissue damage, in cortical areas, in the hippocampus, and in the thalamus. By 24 hours of reperfusion there was no significant difference between the size of areas with altered pH and ATP depletion.

Adenosine Triphosphate↗
PubMed1992

A modified model of reversible middle cerebral artery embolization in rats without craniectomy.

A detailed description is given of a new model of reversible focal cerebral ischaemia in rats. A spherical embolus, attached to the end of an 8-0 surgical thread was injected into the middle cerebral artery (MCA) via the external and internal carotid arteries (ECA and ICA) and could be withdrawn by pulling the extravascular portion of the thread when reperfusion was to follow ischaemia. In contrast to similar techniques, the 8-0 thread did not block blood flow in either the common carotid artery (CCA) or the ICA during ischaemia and, as the CCA did not have to be ligated, flow could be restored via the ipsilateral CCA and ICA after the ischaemic period. Neurological deficit, mortality rate, tissue water content, regional pH, ATP and, in some experiments, electroencephalogram (EEG) and cerebral blood flow (CBF) were evaluated in ischaemia and after various length of reperfusion. The overall mortality rate was 21%; all these animals were lost in the first hours of recirculation. The water content of their brains differed significantly from those who survived 24 hours (81 and 77% respectively). A significant difference in CBF of the ipsi- and contralateral putamen was found immediately after embolization (a CBF decrease of 26 +/- 5 and 5 +/- 5 ml/100 g/min, respectively), and relative hyperperfusion (+23 +/- 27 ml/100 g/min) was observed in the ipsilateral putamen during reperfusion. EEG amplitude declined on both the affected and non-affected sides after embolization (to 54 +/- 8% and 71 +/- 6% of pre-ischaemic values) and remained decreased (66 +/- 8% of control) on the ipsilateral side after 1 hour of reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Polyamine metabolism in transient focal ischemia of rat brain.

Polyamine metabolism was studied in rat brains subjected to 30 min transient cerebral ischemia by measuring the activity of the key enzyme ornithine decarboxylase (ODC) and levels of the polyamines putrescine, spermidine and spermine. A transient increase in ODC activity was apparent after 4 h of recirculation in the ipsilateral cortex and striatum (P less than 0.05). Putrescine levels were significantly increased in the ipsilateral striatum after 4 h of recirculation, and after 24 h of recirculation in both the ipsilateral cortex and striatum. During ischemia spermidine levels were significantly reduced in the ipsilateral hemisphere and spermine levels in the ipsilateral cortex. It is suggested that during ischemia polyamines are released from neurons into the extracellular compartment and cleared into the blood.

Animals↗
PubMed1990

[Ultrasonic methods used in the diagnosis of changes in the carotid artery system].

The duplex method has been recommended as the most effective means, because it is able to detect both morphological and hemodynamical changes, respectively. The duplex is also useful in screening and follow up of stroke patients and the number of conventional angiography can be reduced. Any other ultrasonic diagnostic methods (B-mode, directional Doppler etc.) have a more little diagnostic accuracy but they can be used as complementary methods rising the diagnostic effectiveness. The author summarizes also his own experiences with different ultrasonic equipment compared with angiography. The B-mode has a diagnostic accuracy of 78%. This method is most useful in detecting of stenoses of small and medium size. The diagnostic accuracy of directional Doppler ultrasonography of periorbital vessels has an accuracy of 95% in detecting stenoses greater than 50%, but this method provides no information about the morphology and localization of plaques. The measurement of common carotid artery flow by UQFM--1000 (ultrasonic quantitative flow measurement) was diagnostically effective only in patients with completed occlusion.

Arterial Occlusive Diseases↗
PubMed1990

[Significance of computer analysis of dynamic brain scintigraphy in patients with cerebrovascular disorders].

Dynamic cerebral scintigraphy was performed on 41 patients with cerebrovascular disease. The diagnostic value of parametric images formed by a computer was correlated to angiographic findings and clinical sings, respectively. Having the appropriate software these examinations can be performed with traditional gamma-cameras. Analysis of parametric pictures increases the reliability of the method. Analysis of cinematic display of serial images had the highest sensitivity and accuracy, while time-of-maximum pictures had the highest specificity. In departments, where digitized subtraction angiography, single photon emission computed tomography or positron emission tomography is not available, the non invasive dynamic brain scintigraphy is a useful screening method, its application is proposed by the authors.

Adolescent↗
PubMed1990

Electrophysiological changes in the feline brain during 45 minutes occlusion and 3 hours recirculation of the middle cerebral artery.

The electrophysiological effects of unilateral MCA occlusion for 45 minutes and subsequent recirculation for 3 hours were studied in cats. EEG, steady (DC) potentials, tissue available O2 were measured and metabolic changes were studied. Computed EEG analysis was carried out off line, changes in frequency index and total intensity were analyzed and compared to regional metabolic alterations. It is concluded that: 1. Exenteration of the orbita results in significant and long lasting changes of the EEG, so, a less traumatic method of focal ischemia should be elaborated. 2. Changes in EEG (intensity or frequency content) caused by 45 min MCA occlusion seldom exhibit complete restitution by the end of a 3 hours long recirculation period. 3. Diaschisis can often be detected in this focal ischemic model by computed EEG evaluation. 4. Severe electrophysiological alterations after recirculation usually reflected extended metabolic damage. Mild EEG disturbances can cover both biochemically intact or slightly injured brain tissue.

Animals↗
PubMed1988

The vulnerability of gerbils to focal cerebral ischemia. Neurological signs and regional biochemical changes after ischemia and recirculation.

Gerbils of both sexes were used to study the effects of 30-min ischemia and subsequent recirculation for 4 and 8 days. The mortality rate was 9% during ischemia and 34% in the recirculation period. No close correlation was found between the extent of metabolic changes and the severity of clinical signs after ischemia. Gerbils exhibited severe clinical signs with metabolic patterns of severe hypoxic damage, but with only slight biochemical changes as well, stressing the necessity of detailed examination in regional metabolic studies. According to planimetrical evaluation the most sensitive indicator of ischemic damage was alteration in pH. Decrease in pH without changes in ATP and NADH was associated with severe clinical signs. Biochemical changes were demonstrated after recirculation in some gerbils having severe clinical signs at the end of the ischemic period. The changes in pH and potassium found 8 days after the ischemic insult stress that a 30-min focal ischemia might have long lasting, perhaps irreversible consequences.

Adenosine Triphosphate↗
PubMed1985

Regional changes in tissue pH and glucose content during cortical spreading depression in rat brain.

After eliciting a single passage of spreading depression in rat brain cortex, regional alterations in glucose content and tissue pH were studied in relation to changes in cortical steady potential. Migration of spreading depression into non-invaded cortex was accompanied by a drastic decrease in glucose concentration and tissue pH which persisted longer than the transient depolarization of cortical cells. This delay in metabolic recovery is probably accounted for by severe tissue acidosis which results from the stimulation of anaerobic glycolysis.

Animals↗
PubMed1985

Superoxide dismutase activity in experimental focal cerebral ischemia.

The activity of the free radical scavenger, superoxide dismutase, was studied in focal cerebral ischemia produced in Mongolian gerbils (Meriones unguiculatus) by occluding the right common and left external carotid arteries under halothane anesthesia. After recovery from anesthesia animals were classified according to their neurologic symptoms. Five animals exhibiting neurologic symptoms such as hemiparesis and rolling seizures were reanesthetized 120 min after vascular occlusion and their brains frozen in situ with liquid nitrogen. A series of 20-micron-thick coronal sections was cut in a cryostat; pictorial representations of tissue pH, ATP, and glucose were obtained using fluorescent and bioluminescent techniques. Using a highly sensitive bioluminescent technique, Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and Mn-superoxide dismutase (Mn-SOD) activities were then measured in samples from both ischemic and nonischemic regions of the remaining tissue block. Cu,Zn-SOD and Mn-SOD activities were, respectively, 13.9 +/- 0.7 X 10(3) units/g and 5.4 +/- 0.3 X 10(3) units/g in the nonischemic tissue, and 13.2 +/- 0.6 X 10(3) units/g and 5.0 +/- 0.2 X 10(3) units/g within the ischemic tissue. Thus focal cerebral ischemia does not lead to a global decrease in SOD activity, as observed by others after heart and liver ischemia.

Animals↗
PubMed1985

Multiparametric imaging of blood flow and metabolism after middle cerebral artery occlusion in cats.

In anesthetized adult cats, acute stroke was produced by transorbital occlusion of the left middle cerebral artery. A battery of imaging techniques was used for simultaneous evaluation of regional blood flow, glucose utilization, protein synthesis, pH, and the regional tissue content of glucose, ATP, and potassium. The electrophysiological impact of stroke was monitored by EEG frequency analysis and recording of somatosensory evoked potentials. Two hours after vascular occlusion, a close correlation existed between the degree of electrophysiological changes and biochemical alterations, in particular with the extent of tissue acidosis, ATP depletion, decrease of tissue potassium content, and suppression of protein synthesis. However, there was only a poor correlation with blood flow and glucose utilization. Both of these exhibited a greatly inhomogeneous pattern with regions of reduced, normal, or increased rates. In areas remote from the infarct, the content of biochemical substrates was normal but blood flow was reduced globally by approximately 50% and glucose utilization by approximately 20%. An anatomically defined regional pattern of cerebral or cerebellar diaschisis was not observed. It is concluded that during the acute phase of stroke, imaging of blood flow and glucose utilization does not provide an accurate estimate of the actual functional or metabolic disturbance. For the clinical evaluation of the development or treatment of stroke, in consequence, alternative noninvasive techniques such as imaging of protein synthesis and/or pH may be more relevant.

Adenosine Triphosphate↗