ATPases and lipid peroxidation in the rat sciatic nerve in the course of experimental neoplastic disease.

Peripheral nerve involvement in the course of neoplastic disease represents a clinically significant complication, with clinical uncertainties raising questions as to its pathophysiology. The aim of this study was the analysis of ATPase activities, lipid peroxidation and sulfhydryl groups in the sciatic nerve of tumor-bearing rats. We investigated also morphometric features of the sciatic nerve of experimental animals.

Carotid intima-media thickness better differentiates between groups of stroke patients and persons without cerebrovascular disease than other conventional and novel risk factors.

When measured by ultrasound, the morphological markers of carotid atherosclerosis such as intima-media thickness (IMT) and cross-sectional plaque area have been associated with the risk of ischaemic stroke. We set out to determine whether the morphological parameters of the carotid arteries made it possible to better differentiate between groups of older atherothrombotic stroke patients and persons without cerebrovascular disease than conventional and novel risk factors of stroke. Of the total number of 623 persons examined, 54 stroke patients (mean age 63.

Apoptotic proteins in the course of aging of central nervous system in the rat.

Studies were performed on the level of cells with damaged DNA (TUNEL), the level of protein engaged in DNA repair (PARP) and the level of proteins indicating the extent of apoptosis (Bax:Bcl-2) (Western blot). The studies were performed on cerebral cortex (GM), white matter (WM), medulla oblongata (MO), cerebellum (C) of rats, 3.0-3.

Oxidative damage to DNA, p53 gene expression and p53 protein level in the process of aging in rat brain.

Levels of 8-oxo2'dG (HPLC), p53 mRNA (PCR) and p53 protein (Western Blot) were estimated in four structures of rat brain, including grey matter (GM) of cerebral cortex, cerebral white matter (WM), cerebellum (C) and medulla oblongata (MO) of control (3.0-3.5-month-old) rats, 12- and 24-month-old rats.

Patterns of free and esterified sterol fractions of the cerebral white matter in severe and moderate experimental hypoxia.

Cerebral sterols were examined in Wistar strain rats, subjected 4 h, 24 h, 14 days or 2 months earlier to severe (2% oxygen) and moderate (7% oxygen) experimental hypoxia. From brains of the experimental animals myelin was isolated and examined by gas chromatography coupled with mass spectrometry (GC-MS) to separate and to identify free and esterified (following hydrolysis) cerebral sterols. In both types of hypoxia, the same compounds were identified in fractions of free and esterified sterols.

The effect of moderate hypoxia on free sterols: content and pattern in white matter.

Wistar rats underwent moderate hypoxia by exposing them to a respiratory gas mixture containing 7% oxygen, for 30 min. The myelin was analyzed at 4 h 24 h, day 14, and day 60 after hypoxia. The group of neutral lipids isolated from myelin was analyzed by GC-MS (gas chromatography-mass spectrometry) to separate and measure free sterols.

[Lipid image in glioblastoma multiforme].

Changes in the content and composition of lipids in brain tumours of different degree of malignancy are still the subject of numerous scientific studies. It is known that in developing brain tumours structural and functional changes of its cells, take place, in which lipids play a crucial role. The examination of the lipid spectrum was conducted in a material extracted from tumour adjacent areas (by means of fenestration) as well as from tumours themselves in 11 patients (mean age 56.

Free sterols in the rat white matter following experimental global ischemia.

The pattern of free sterols occurring in the cerebral white matter was studied in an experimental model of global ischemia that was induced in rats by means of the method described by KORPACHEV et al. (1982). Sterol isolation, separation and identification was accomplished by suitable extraction procedures followed by gas-chromatography-mass spectrometry of the purified sterol extracts.

Composition of the cerebral white matter sterol ester fraction in severe experimental hypoxia.

Severe hypoxia was induced in adult Wistar rats by means of exposure to an atmosphere containing 2.0 kPa of oxygen for a period of 3 minutes. The animals were sacrificed at 4 different periods following the hypoxia incident: 4 and 24 hours, 14 days and 2 months, respectively, and sterol esters (ES) were isolated from the myelin fraction of the cerebral white matter.

Free sterols of the cerebral white matter in experimental severe hypoxia.

Wistar rats, aged 3.5 months, were subjected to severe hypoxia by placing them for 3 minutes in an atmosphere containing 2 kPa of oxygen. The myelin fraction was isolated from brains of the experimental animals at the following periods after the hypoxia event: 4 and 24 hours, 14 days, 2 months.

Transformation of sterols pattern in course of late development of rat brain.

Free sterol content was determined in the late period of development of the rat brain using the method of gas chromatography-mass spectrometry. The results obtained have shown that the free sterol pattern is very unstable in course of late period of ontogenic development. In contrast to young adult rats, in which apart from cholesterol only trimethylcholestenon and trace amounts of desmosterol were visible, in the brain of 1 and 2 years old rats some new sterols are appearing.

Myelin lipids and proteins in experimental global ischemia.

The experiments were performed on white rats, in which clinical death was induced according to the method described by Korpatchev et al. (1982). After cardiac arrest and cessation of respiratory function lasting 5 minutes resuscitatory action was performed.

Free sterols in senile human brain.

Autopsy material of 18 patients, who died between 66-86 years of age and of 4 ones, who died between 20 and 38 years of age was investigated. The white matter of frontal lobe, corpus callosum and cerebellum was studied using histological and biochemical methods. According to the results of neuropathological studies, the material of aged patients was divided into two subgroups: patients with vascular changes only and brains with senile atrophy of Alzheimer type.

Myelin proteins in aging human brain.

Autopsy material of 13 persons who died between 70 and 89 yrs old and of patients who died between 27 and 44 yrs old was studied. White matter of temporal, parietal, and occipital lobes was investigated using histological and biochemical methods. According to results of neuropathological studies, the material of aged patients was divided into two subgroups: (a) brains with vascular changes only and (b) patients with senile atrophy of Alzheimer type.

Myelin lipids in ischemic stroke.

Slices of ischemic focus (infarct area) and of the contralateral frontal lobe were submitted to histological and biochemical studies. The obtained results indicate that in stroke cases the necrotic focus as well as contralateral brain hemisphere are characterized by a marked decrease of cholesterol and cerebrosides content and an increase of lysophosphatidylcholine and cholesterol esters in the myelin fraction. We conclude that ischemia as well as the degenerative aging process are both responsible for the abnormal lipid pattern in the myelin of the white matter in stroke cases.

Pattern of myelin proteins in moderate hypoxia.

Myelin proteins isolated from the brain of Wistar rats subjected to moderate hypoxia (7% of oxygen in a respiration gaseous mixture) for 30 min were investigated. Among the various protein fractions Wolfgram protein happened to be most markedly affected, demonstrating considerably lowered percentages in all experimental groups, starting from 24 h after hypoxia. Our findings compared with those obtained in other experimental conditions lead to the conclusion that changes in the myelin protein pattern are characteristic for particular morbid processes evoked by various pathogenic factors.

Influence of experimental hypoxia on content and composition of free fatty acids in cerebral white matter.

The content and spectrum of free fatty acids were studied in the cerebral white matter, on Wistar rats exposed to acute hypoxia (2% of oxygen in a respiratory mixture) for 3 min. The total content of fatty acids, especially of tetraenoic ones, rose sharply already 4 min after hypoxia and persisted elevated even 2 months after the hypoxia. The results showed that the degradation of phospholipids-containing biological membranes in the nervous tissue of the white matter starts immediately after hypoxia, and is continued for months.

Myelin lipids in aging human brain.

The studies were performed on autopsy material of 18 patients who died between the ages of 70-89 y, and of 5 patients who died between 23-44 ys of age. White matter of the frontal lobe and of oerebellum was submitted for histological and biochemical analysis. The neuropathological data provided a rationale for dividing the material into two subgroups: one including patients mainly with vascular changes in the brain, and the other consisting of patients with senile atrophy of the Alzheimer type.

Myelin lipids of the rat brain in experimental hypoxia.

The pattern of cerebral myelin lipids was studied in Wistar rats exposed to mild hypoxia (7% of oxygen in a respiratory mixture) for 30 min. The most pronounced change involved a marked increase in cholesterol esters and lysophosphatidylcholine content in the myelin fraction. The results obtained indicate that mild hypoxia induces a lesion of myelin membranes but does not provoke the reaction of lymphocytes and macrophages, which by production of myelinolytic factors, evoke demyelination.