Hodnocení opotřebení komponent hydraulického systému na základě analýzy stupně degradace hydraulického oleje

Kompleksowe testy mające na celu określenie okresu trwałości oleju w celu zapobiegania i wczesnej diagnostyki usterek układu hydraulicznego obejmują ciągłe monitorowanie degradacji oleju (lepkość kinematyczna w 40°C, liczba kwasowa, degradacja termiczno-oksydacyjna), zanieczyszczeń oleju (woda, klasa czystości), stężeń metali (Fe, Pb, Cu) w oleju i kształtu ich cząstek. Analiza korelacji potwierdziła znaczenie statystycznej zależności między zanieczyszczeniem oleju a zużyciem układu hydraulicznego.Komplexní testy pro stanovení životnosti oleje pro prevenci a včasnou diagnostiku poruch hydraulického systému zahrnují nepřetržité sledování degradace oleje (kinematické viskozity při 40 °C, čísla kyselosti, termo-oxidační degradace), znečištění oleje (vody, třídy čistoty), koncentrace kovů (Fe, Pb, Cu) v oleji a tvar jejich částic. Korelační analýza potvrdila významnou statistickou závislost mezi znečištěním olejem a opotřebením hydraulického systému

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome: Treatment approach depends on disease course

Introduction. Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare inflammatory central nervous system (CNS) disorder, chiefly involving the brainstem, especially the pons. The diagnosis is challenging, requires careful exclusion of alternative diagnoses and a targeted therapeutic approach. CLIPPERS is known to respond well to corticosteroids, but the treatment needs to be long-term and can cause significant side-effects. Moreover, subsequent corticosteroid withdrawal often leads to a relapse. It has been suggested that anti-CD20 molecules could benefit several antibody-mediated CNS inflammatory diseases, including CLIPPERS. Case report. This paper describes two cases of CLIPPERS. The first demonstrates the benefit of early introduction of corticosteroids with side effects in cases of long-term use. The second demonstrates the efficacy of ocrelizumab (anti-CD20 molecule) in a severe course of CLIPPERS. Conclusion. These two cases bring attention to this rare, often misdiagnosed but treatable disease

Effect of Methionine Diet on Time-Related Metabolic and Histopathological Changes of Rat Hippocampus in the Model of Global Brain Ischemia

Hyperhomocysteinemia (hHcy) represents a strong risk factor for atherosclerosis-associated diseases, like stroke, dementia or Alzheimer’s disease. A methionine (Met)-rich diet leads to an elevated level of homocysteine in plasma and might cause pathological alterations across the brain. The hippocampus is being constantly studied for its selective vulnerability linked with neurodegeneration. This study explores metabolic and histo-morphological changes in the rat hippocampus after global ischemia in the hHcy conditions using a combination of proton magnetic resonance spectroscopy and magnetic resonance-volumetry as well as immunohistochemical analysis. After 4 weeks of a Met-enriched diet at a dose of 2 g/kg of animal weight/day, adult male Wistar rats underwent 4-vessel occlusion lasting for 15 min, followed by a reperfusion period varying from 3 to 7 days. Histo-morphological analyses showed that the subsequent ischemia-reperfusion insult (IRI) aggravates the extent of the sole hHcy-induced degeneration of the hippocampal neurons. Decreased volume in the grey matter, extensive changes in the metabolic ratio, deeper alterations in the number and morphology of neurons, astrocytes and their processes were demonstrated in the hippocampus 7 days post-ischemia in the hHcy animals. Our results suggest that the combination of the two risk factors (hHcy and IRI) endorses and exacerbates the rat hippocampal neurodegenerative processes

Imaging Methods Applicable in the Diagnostics of Alzheimer’s Disease, Considering the Involvement of Insulin Resistance

Alzheimer’s disease (AD) is an incurable neurodegenerative disease and the most frequently diagnosed type of dementia, characterized by (1) perturbed cerebral perfusion, vasculature, and cortical metabolism; (2) induced proinflammatory processes; and (3) the aggregation of amyloid beta and hyperphosphorylated Tau proteins. Subclinical AD changes are commonly detectable by using radiological and nuclear neuroimaging methods such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), and single-photon emission computed tomography (SPECT). Furthermore, other valuable modalities exist (in particular, structural volumetric, diffusion, perfusion, functional, and metabolic magnetic resonance methods) that can advance the diagnostic algorithm of AD and our understanding of its pathogenesis. Recently, new insights into AD pathoetiology revealed that deranged insulin homeostasis in the brain may play a role in the onset and progression of the disease. AD-related brain insulin resistance is closely linked to systemic insulin homeostasis disorders caused by pancreas and/or liver dysfunction. Indeed, in recent studies, linkages between the development and onset of AD and the liver and/or pancreas have been established. Aside from standard radiological and nuclear neuroimaging methods and clinically fewer common methods of magnetic resonance, this article also discusses the use of new suggestive non-neuronal imaging modalities to assess AD-associated structural changes in the liver and pancreas. Studying these changes might be of great clinical importance because of their possible involvement in AD pathogenesis during the prodromal phase of the disease

NMR in Biomedicine / Spatial variability and reproducibility of GABA-edited MEGA-LASER 3D-MRSI in the brain at 3T

The reproducibility of gamma-aminobutyric acid (GABA) quantification results, obtained with MRSI, was determined on a 3T MR scanner in healthy adults. In this study, a spiral-encoded, GABA-edited, MEGA-LASER MRSI sequence with real-time motion-scanner-instability corrections was applied for robust 3D mapping of neurotransmitters in the brain. In particular, the GABA(+) (i.e. GABA plus macromolecule contamination) and Glx (i.e. glutamate plus glutamine contamination) signal was measured. This sequence enables 3D-MRSI with about 3cm(3) nominal resolution in about 20min. Since reliable quantification of GABA is challenging, the spatial distribution of the inter-subject and intra-subject variability of GABA(+) and Glx levels was studied via test-retest assessment in 14 healthy volunteers (seven men-seven women). For both inter-subject and intra-subject repeated measurement sessions a low coefficient of variation (CV) and a high intraclass correlation coefficient (ICC) were found for GABA(+) and Glx ratios across all evaluated voxels (intra-/inter-subject: GABA(+) ratios, CV similar to 8%-ICC>0.75; Glx ratios, CV similar to 6%-ICC>0.70). The same was found in selected brain regions for Glx ratios versus GABA(+) ratios (CV varied from about 5% versus about 8% in occipital and parietal regions, to about 8% versus about 10% in the frontal area, thalamus, and basal ganglia). These results provide evidence that 3D mapping of GABA(+) and Glx using the described methodology provides high reproducibility for application in clinical and neuroscientific studies.KLI 61-B00(VLID)308377