Contribution of tumor necrosis factor alpha to the pathogenesis of stroke

Tumor necrosis factor alpha (TNF-alpha) is a protein of a cellular origin belonging to a group of proinflammatory cytokines. A rapid overproduction of TNF-alpha in a cerebral post-ischemic inflammatory response leads to the stimulation of adhesive molecules expression with subsequent accumulation of leukocytes in the ischemic focus, which is preceded by their adhesion and migration. The TNF-alpha proinflammatory activity results mainly in extending the area of the brain infarct, which brings about negative clinical implications. Being the final morphological effect of ischemic stroke, TNF-alpha appears also to contribute to neuronal necrosis by its involvement in the process of apoptosis as well as in the death of neurons. The present study describes and discusses mainly the contribution of TNF-alpha to the formation of ischemic focus in the brain

Adhesion molecules of immunoglobulin gene superfamily in stroke

Stroke-induced inflammatory reaction leads to the accumulation of leukocytes in the brain ischaemic region, where they exert a detrimental effect - promotion and extension of cerebral damage. Intracerebral infiltration of peripheral blood leukocytes requires prior endothelial-leukocyte interactions that are mediated by such cell surface proteins as adhesion molecules. Among adhesion molecules, it is the immunoglobulin gene superfamily (IgSF) that is responsible for strong attachment and transendothelial migration of leukocytes. The principal members of IgSF are: intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1). In this review the following issues were described and discussed: an increased expression of ICAM-1 and VCAM-1 in ischaemic brain as well as a detection of their soluble(s) forms in sera of stroke victims. The presented data suggest the involvement of both ICAM-1 and VCAM-1 in the sequence and timing of the infiltration of leukocytes into the brain ischaemic zone after stroke. They have also revealed changes in serum concentrations of sICAM-1 and sVCAM-1 that are characteristic for stroke. Recently, increase in sPECAM-1 levels in serum and cerebrospinal fluid (CSF) has been shown within 24 h of the onset of stroke, having indirectly suggested involvement of the molecule in the inflammatory events during the early phase of stroke

The levels of TNF-alpha in cerebrospinal fluid and serum do not correlate with the counts of the white blood cells in acute phase of ischaemic stroke

Stroke-induced inflammatory reaction, which leads to invasion of leukocytes into the evolving brain infarct, seems to play a key role in the deterioration of brain ischaemic impairment. We have studied CSF and serum levels of tumour necrosis factor-alpha (TNF-alpha), the potent proinflammatory cytokine, and peripheral white blood cells (WBC) counts in patients within the first 24 hours of ischaemic stroke. TNF-alpha levels in CSF and serum as well as WBC counts were increased. There was no correlation between TNF-alpha levels either in CSF and serum or in WBC counts. The results of our study suggest that increased CSF TNF-alpha levels may represent acute intracerebral inflammation in stroke, whereas elevated levels of TNF-alpha in serum may reflect the peripheral proinflammatory state as well as stroke-induced systemic inflammatory reaction. Increased CSF and serum TNF-alpha levels do not correlate with the elevation of WBC counts, suggesting that TNF-alpha overexpression observed in early phase of stroke is not dependent on increased total number of peripheral leukocytes

Acute ischaemic stroke increases the erytrocyte sedimentation rate, which correlates with early brain damage

The acute phase response follows tissue injury and contributes to its exacerbation with pro-inflammatory and pro-thrombotic mechanisms. Acute phase proteins promote erythrocyte aggregation and falling, with the result that the erythrocyte sedimentation rate (ESR) is a measure of the acute phase response. As the acute phase response accompanies ischaemic brain damage, we studied ESR values in patients within the first 24 hours of ischaemic stroke and evaluated whether these values may be related to the volume of anatomically relevant single hemispheric brain computed tomography (CT) areas observed at the same period, indicating early stroke-related cerebral changes. We observed an increase in ESR in stroke patients and a positive correlation between the ESR values and the volume of early brain CT hypodense areas. The results suggest that elevation in ESR values is observed soon after a stroke and may reflect the relationship between the degree of acute phase response in the early phase of ischaemic stroke and the extent of local brain damage

On recombination in strong laser fields: effect of a slow drift

The dynamics of the recombination in ultrastrong atomic fields is studied for one-dimensional models by numerical simulations. A nonmonotonic behavior of the bound state final population as a function of the laser field amplitude is examined. An important role of a slow drift of an electron wave packet is observed.Comment: 4 pages, 6 figure

Photodetachment in superintense fields: the problem of stabilization and a role of rescattering wavepacket's fragments

Photodetachment in ultrastrong laser field in two spatial dimensions is investigated numerically. The problem of an adiabatic stabilization is discussed, in particular it is shown that a quick drift in the direction of the electric field and a magnetic drift cannot be avoided simultaneously. A qualitative behavior of the packet for a short-range binding potential is contrasted with that for a soft-core potential, in particular dynamical effects due to a rescattering of the fragments separated from the main packet are demonstrated.Comment: 14 pages, 7 figure

Beyond Climate Anxiety: Development and Validation of the Inventory of Climate Emotions (ICE): a Measure of Multiple Emotions Experienced in Relation to Climate Change

There is a growing research interest in the affective aspects of climate change and their links with pro-climate engagement. Yet, psychometrically valid instruments assessing the wide panorama of emotional responses to climate change are limited. Here, we report on the development and validation of the Inventory of Climate Emotions (ICE), a self-report measure of multiple emotions experienced in relation to climate change. Based on qualitative exploration, literature review, along with expert and target population content validation, we operationally defined a spectrum of emotional responses to climate change which guided the formulation of a large initial item pool. High psychometric quality of the ICE was secured in two quantitative studies conducted in samples from the general population in Poland. In Study 1, based on exploratory factor analysis, we indicate that a broad range of emotional responses to climate change can be viably captured by 8 underlying factors: anger, contempt, enthusiasm, powerlessness, guilt, isolation, anxiety, and sorrow. This structure was corroborated in Study 2 with confirmatory factor analysis on an independent sample. Across studies, we provide evidence for the reliability and validity of the ICE in terms of internal consistency of the subscales and convergent, discriminant and concurrent validity. We also show the functionality of the ICE in the context of pro-climate behaviour. The ICE provides an integrative approach to emotional responses to climate change and it can be used to further the understanding of the complex role of emotions in climate change engagement

Impact of ozonisation on pro-health properties and antioxidant capacity of ‘Honeoye’ strawberry fruit

The objective of the research was to determine the impact of concentration and ozonisation time on the selected chemical properties and total antioxidant capacity of ‘Honeoye’ strawberries cultivar. Efficiency of gaseous ozone usage as a method of extending the fruit shelf life was proved. Strawberries were exposed to ozone stream with concentration of 0.3–1.2 mg/L, within 60, 120, 150 and 180 min. The scope of research included measurements of the titratable acidity, content of soluble solid substances and the following pro-health characteristics: the total antioxidant capacity, phenolic compounds content and vitamin C content. On the second, fourth and sixth day of storage, an assessment was carried out on the fruit mass changes. Statistically significant differences (p < 0.05) in the titratable acidity changes and soluble solids concentration were reported. The application of ozone allowed reduction of strawberries weight losses during storage without a negative impact on their pro-health properties

Polish Multicenter Registry (Pol-LAS-SE registry). Stress echocardiography in low-gradient aortic stenosis in Poland: numbers, settings, results, complications and clinical practice

Background: The diagnostic workup of low-gradient aortic stenosis (LG AS) is a challenge in clinical practice.Aims: Our goal was to assess the diagnostic value of stress echocardiography (SE) performed in patients with undefined LG AS with low and preserved ejection fraction (EF) and the impact of its result on therapeutic decisions in Polish third level of reference.Methods: All the patients with LG AS and with SE performed were recruited in 16 Polish cardiology departments between 2016 and 2019. The main exclusion criteria were as follows: moderate or severe aortic or mitral regurgitation and mitral stenosis.Results: The study group included 163 patients (52% males) with LG AS who underwent SE for adequate diagnostic and therapeutic decision. In 14 patients DSE was non-diagnostic. The mean aortic valve (AV) pressure gradient was 24.1 (7.3) mm Hg, while an AV area was 0.86 (0.2) cm2. Among 149 patients with conclusive DSE, severe AS was found in 59.8%, pseudo-severe in 22%, and moderate AS in 18%. There were no cases of death or vascular events related to DSE. Among 142 patients 63 (44%) patients had an aortic valve intervention in a follow-up (median: 208 days; lower-upper quartile: 73–531 days). Based on the result of the DSE test, severe AS was significantly more often associated with qualification to interventional treatment compared to the moderate and pseudo-severe subgroups (P &lt;0.0001).Conclusions: The DSE test in severe AS is a valuable diagnostic tool in patients with LG AS in Poland