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Biomedical subjects

A V Pozdniakov

Publications and source records attributed to A V Pozdniakov.

At least 19 recordsLinked to original sources
PubMed2006

[Clinical and radiological (PET, MRI) correlations depending on disease progression in patients with multiple sclerosis].

The aim of the study was to investigate the structural-functional changes in the cerebral gray matter (cortical and subcortical areas) of patients with multiple sclerosis (MS) depending on the disease severity. One hundred and seven patients (107) with definite diagnosis of MS (Mc Donald's criteria), aged 16-60 years, illness duration 1-30 years, and 21 healthy age-matched controls have been studied. Neurological assessment including Kurtzke and EDSS scales (range 0-8) was performed in all the patients. The patients and controls underwent MRI with a 1,5 imager and PET using 18F-flurodeoxyglucose (FDG). A type of the disease course was determined as remitting in 63 patients, primarily-progressive in 8, remitting progressive in 6 and secondary-progressive in 30. To analyze pathogenesis of the disease progression, the patients were divided into 3 clinical groups: (1) remitting (RRMS, n=63); (2) progressive (PRMS) with EDSS < or =6 (n=34); 3) PRMS with EDSS >6 (n=11). Along with the progression of MS from RRMS to PRMS and increasing of EDSS, the rCMRglu reduction of the cerebral gray matter developed from the supplementary motor cortex of a dominant hemisphere to the marked global reduction of cerebral metabolic rate in the PRMS group (EDSS >6). In the PRMS group with EDSS56, there was functional reorganization of cortical and subcortical areas compensatorily developing with the disease progression. In the PRMS group with EDSS >6, the data obtained did not support the evidence for the regional compensatory increase of rCMRglu in the same brain areas. Decompensation of the functional cortical reorganization in the PRMS group with EDSS >6 correlated with diffuse brain atrophy as well as with atrophy of the gray matter of the regional basal ganglia, first of all of the thalamus.

Adolescent↗
PubMed2002

[Possibilities of magnetic resonance visualization in the diagnosis of multiple sclerosis].

Magnetic-resonance imaging (MRI) is considered to be the most informative non-invasive method in diagnosis, differential diagnosis and estimation of activity of multiple sclerosis (MS). MRI data of 270 patients with clinically and laboratory definite MS were analyzed to assess diagnostic MRI-criteria for MS, MRI presentations at the time of first clinical manifestation of the disease, neuroimaging patterns in children and elderly persons with MS. The MRI variants of MS are substantiated. Neuroimaging data of cervical spinal cord in 28 patients with MS are presented in parallel with corresponding clinical data. The most typical patterns are singled out. The data of brain 1H-magnetic-resonance spectroscopy (MRS) in 20 patients with MS and 8 patients with inflammatory and vascular disorders were analyzed to reveal biochemical distinction between MS and non-MS lesions as well as changes in normal appearing white matter in MS. The differential-diagnostic value of MRS is limited although decreased N-acetyl-aspartate peak is characteristic for MS lesions and in some cases in normal appearing white matter in primary-progressive MS.

Brain↗
PubMed2001

[Proton magnetic-resonance spectroscopy in remitting and secondary-progressive multiple sclerosis].

Proton magnetic-resonance spectroscopy (PMRS) was used to measure the levels of inositol/myoinositol (Ins), choline, creatine/phosphocreatine (Cr), glutamine/glutamate (Glx/Glx1), N-acetylaspartate (NAA), gamma-aminobutyric acid (GABA) and lipids were measured in the foci of demyelinization in the brains of 59 patients with multiple sclerosis (MS). Magnetic-resonance imaging was performed during a single investigation. A control group comprised 20 healthy individuals. PMRS revealed significant alterations in the levels of metabolite in all the patients as compared with the controls: decreases in NAA by 23-52%, in Cr by 12-21%, in choline by 15-26%; increases in Ins by 51-63%; as well as the appearance of lipids (up to 100%). In MS, there were reduction in NAA/Cr, NAA/choline, and NAA/choline/Cr ratios by 12-53; 10-19; and 57-82%, respectively. As compared with the remitting MS, secondary-progressive MS showed decreases in the content of NAA by 23-25%, NAA/(choline + Cr) by 48-54% and increases in the levels of Ins and lipids by 50-76%. In remitting MS, there was a strong correlation between the NAA/Cr ratio and the volume brain lesion. It is concluded that PMRS evaluated the extent, pattern and activity of demyelinization (by the levels of Ins, NAA, Cr, lipids) and the intensity of cerebral atrophy (by NAA levels, NAA/Cr ratio). The findings testify that there are neurochemical differences between remitting and secondary-progressive MS.

Adolescent↗
PubMedDate not supplied

[Proton magnetic resonance spectroscopy in diagnostics of epilepsy].

Present paper presents proton MRS investigation results. The investigation was carried out with Magnetom Vision device. Twenty-five patients in the age of 20-44 years suffering with generalization epileptic fits validated by EEG (no visible changes on MRT) were examined. In all cases independently on the localization of the changes, decreasing of NAA and increasing of Cho were recorded. At one side temporal lobe injury recorded by EEG at the damaged part decreasing of NAA/Cr and NAA/Cho + Cr ratios were registered. Patients with bilateral changes registered by EEG showed non-equal changes of metabolite concentration on both sides. Examination of patients suffering with distinct symptoms of temple epileptics has shown ipsilaterality decrease of NAA and Cr concentration. But on the injured side NAA/Cr ratio decrease was more distinct. In general, the laterality was recorded in 14 patients out of 22 with pathological changes registered by proton MRS and in 10 patients out of 14 the above mentioned changes corresponds to the side of the fit initiation. In the patients with bilaterality changes NAA/Cr ratio asymmetry was recorded in all cases, but the most distinctly in the medium part of the temple lobe. Comparison of data recorded in 8 patients suffering with one side fit complex has shown significant asymmetry of metabolites which was observed in ipsilaterality and contra laterality NAA ratio obtained in hippocampal areas. Difference in NAA ratio obtained between left and right sides are 19-25%. Left-right ratio of other metabolites corresponded to that ratio in the control group and was symmetrical.

Adult↗
PubMedDate not supplied

[Proton magnetic resonance spectroscopy in the diagnosis of brain diseases].

The role and position of proton magnetic resonance spectroscopy have been studied in diagnosis of brain diseases. 114 patients with various diseases of the brain have been examined (multiple sclerosis--41, insults of different etiology--17, encephalopathy--12, AIDS infection--23, epilepsy--12, reduction of the intellectual ability of various etiology--9). MR tomography and 1HMR Spectroscopy have been done with Magnetom "Vision", 1.5 T (Siemens) in the CRIRR, St. Petersburg. To get a proton magnetic-resonance specter, SVS_STEAM, SVS_STEAM-20 and SVS_SE-135 sequences have been used with the following parameters: TR 5000 ms, TE 10, 20 and 135 ms respectively, number of acquisitions--100. Typical changes of metabolities in every group have been revealed. The performed examinations have shown that proton magnetic resonance spectroscopy enables to widen our know-ledge about the nature of pathologic changes, that grow with different diseases of the brain.

Adolescent↗
PubMedDate not supplied

[New morphological data on multiple sclerosis].

The brain from 6 patients who died of multiple sclerosis was studied with MR tomography (MRT), macroscopy, light (CD 3, CD 20, LCA antigens) and electron microscopy (EM). Typical foci of demyelinization (plaques) were found in all cases. Alterations of brain arteries were found particularly in arteries of narrow lumen--with disturbance or even absence of elastin and muscle layer. Up to 30% of the vessels were surrounded by microcavities. Perivascular infiltrates consisting primarily of T lymphocytes were observed around the vessels (up to 70% of all vessels). This indicates the importance of vascular changes in the disease pathogenesis. Four variants of demyelinization (plaques) are distinguished depending on the degree of destruction of myelin, axons and glia. Two types of cells were found in the plaques with most pronounced changes: astrocytes and newly formed oligodendrocytes. Classification of plaques is suggested.

Adolescent↗
PubMedDate not supplied

[X-ray diagnosis of peptic ulcers of the jejunum].

The paper is devoted to a study of the results of clinicoroentgenological and endoscopic investigation of 188 patients aged 23 to 60 who developed jejunal peptic ulcer. It was done to specify the features of an x-ray picture of jejunal peptic ulcers with relation to the cause of ulcer development and optimum methods of x-ray investigation. The predominant localization of peptic ulcer in the jejunal efferent loop and its typical ulcero-cicatricial deformity were established. Jejunal peptic ulcers developing as a result of an insufficient area of resection, are characterized by a relatively benign course of the disease. In case ulcer development was determined by the residual antral stomach mucosa at the duodenal stump or by the Zollinger-Ellison syndrome, considerable pathological changes (gigantic ulcer sizes greater than 2.5 cm and a sharp deformity of the jejunal efferent loop) were noted.

Adult↗
PubMedDate not supplied

[Osmotic and ion-regulatory responses in chronic diffuse liver pathology].

Patients with chronic hepatitis were found to develop an inadequate di- and natriuretic responses to osmotic agents administered into the gastrointestinal tract. In liver cirrhosis, the intensity of adaptive responses decreases or they completely disappeared. The causes for these abnormalities are impairment of osmoregulatory reflex links and dyscoordination of humoral factors.

Chronic Disease↗