Three major cytokines, namely, tumor necrosis factor (TNF-alpha), interleukin (IL)-1, and IL-6 are produced by cultured brain cells after various stimuli such as ischemia. Neurones, astrocytes, microglia and oligodendrocytes can produce inflammatory mediators, and cytokine receptors are expressed constitutionally throughout the Central Nervous System (CNS), albeit at low levels. Cytokines are involved in virtually every facet of stroke and they have numerous pro-inflammatory and pro-coagulant effects on endothelium. TNF-alpha expression after stroke stimulates expression of tissue factor and adhesion molecules for leukocytes, release of interleukin-1 (IL-1), nitric oxide, factor VIII/von Willebrand factor, platelet-activating factor and endothelin, suppression of the thrombomodulin-protein C-protein S system, reduction of tissue-plasminogen activator and release of plasminogen activator inhibitor-1. Research into the actions of IL-1beta in the brain initially focused on its role in host defence responses to systemic disease. IL-1beta can also elicit an array of responses which could either inhibit, exacerbate or induce neuronal damage and death. IL-6 can be induced by a variety of molecules including IL-1, TNF-alpha, transforming growth factor-beta and prostaglandins (PGs), and many other mediators such as b-amyloid, interferon-g (IFNg) and IL-4 can potentiate these primary inducers, highlighting the complex nature of IL-6 modulation. Several studies reported that plasma levels of TNF-alpha and IL-6 are associated with prognosis after ischemic stroke and our group showed that plasma levels of cytokines such as TNF-alpha, IL-1beta are different in every diagnostic subtype of ischemic stroke, and how plasma levels of some immunoinflammatory markers and thrombotic-phybrinolitic markers are predictive of acute ischemic stroke diagnosis in the acute setting.

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Animal models of focal ischaemia induced by middle cerebral artery occlusion (MCAO) provide most evidence for cellular inflammatory responses in stroke. Permanent MCAO results in a modest neutrophil infiltration at 24 h after ischaemia, predominantly around arterial vessels at the margins of infarction, whereas MCAO with subsequent reperfusion is associated with substantial infiltration by neutrophils throughout the entire infarct. Several studies show that C-reactive protein (CRP), an inflammatory marker, is associated with stroke outcomes and future vascular events. Several drugs, especially hydroxymethylglutaryl coenzyme A reductase inhibitors (statins), have been demonstrated to reduce hsCRP levels independently of their effects on plasma cholesterol. Various cytokines were shown to be expressed in the injured brain. Recent investigations demonstrated that mRNAs of above cytokines were induced in the ischemic rat brain. TNF-alpha is a pleiotropic cytokine that mediates key roles in many physiological and pathological cellular processes including acute and chronic inflammation, programmed cell death or apoptosis, anti-tumor responses, and infection. Pharmaceutical industry to search a small molecule TNF inhibitor have taken multiple strategies. Significant protection after in vivo oral use of SB-239063 from brain injury and neurological deficits was observed in one study. In the same study significant protection from brain injury and neurological deficits was also demonstrated due to i.v post-stroke treatment with the same compound. Leukocyte-endothelial adhesion process consists of several steps, beginning with rolling of the leukocyte on the endothelial surface until it has slowed down to such a degree that it sticks to the endothelium. Treatment with a murine anti-ICAM-1 antibody (enlimomab) has been investigated in patients with acute ischemic stroke in the Enlimomab Acute Stroke Trial (EAST). Unfortunately, the case fatality rate in this trial was significantly higher in the enlimomab patient group than in the placebo group. Furthermore, experimental data have shown that focal cerebral ischemia induces a time-dependent activation of granulocytes, lymphocytes, and macrophages. Dissipation of ATP by CD39 reduced P2X7 receptor stimulation and thereby suppressed baseline leukocyte alphaMbeta2-integrin expression. As alphaMbeta2-integrin blockade reversed the postischemic, inflammatory phenotype of Cd39-/- mice, these data suggest that phosphohydrolytic activity on the leukocyte surface suppresses cell-cell interactions that would otherwise promote thrombosis or inflammation.

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Background Respiratory failure due to COVID-19 pneumonia is associated with high mortality and may overwhelm health care systems, due to the surge of patients requiring advanced respiratory support. Shortage of intensive care unit (ICU) beds required many patients to be treated outside the ICU despite severe gas exchange impairment. Helmet is an effective interface to provide continuous positive airway pressure (CPAP) noninvasively. We report data about the usefulness of helmet CPAP during pandemic, either as treatment, a bridge to intubation or a rescue therapy for patients with care limitations (DNI). Methods In this observational study we collected data regarding patients failing standard oxygen therapy (i.e., non-rebreathing mask) due to COVID-19 pneumonia treated with a free flow helmet CPAP system. Patients’ data were recorded before, at initiation of CPAP treatment and once a day, thereafter. CPAP failure was defined as a composite outcome of intubation or death. Results A total of 306 patients were included; 42% were deemed as DNI. Helmet CPAP treatment was successful in 69% of the full treatment and 28% of the DNI patients (P < 0.001). With helmet CPAP, PaO2/FiO2 ratio doubled from about 100 to 200 mmHg (P < 0.001); respiratory rate decreased from 28 [22–32] to 24 [20–29] breaths per minute, P < 0.001). C-reactive protein, time to oxygen mask failure, age, PaO2/FiO2 during CPAP, number of comorbidities were independently associated with CPAP failure. Helmet CPAP was maintained for 6 [3–9] days, almost continuously during the first two days. None of the full treatment patients died before intubation in the wards. Conclusions Helmet CPAP treatment is feasible for several days outside the ICU, despite persistent impairment in gas exchange. It was used, without escalating to intubation, in the majority of full treatment patients after standard oxygen therapy failed. DNI patients could benefit from helmet CPAP as rescue therapy to improve survival. Trial Registration: NCT04424992

Background Tocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. Methods A multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival. Results In the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6–24.0, P = 0.52) and 22.4% (97.5% CI: 17.2–28.3, P < 0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Conclusions Tocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline. Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092).

The aim of the present study was to determine the rates of stroke in patients with chronic NVAF (non-valvular atrial fibrillation), evaluating the relationship between plasma levels of inflammatory variables at admission and the occurrence of stroke during a 3-year follow-up. A total of 373 consecutive patients with chronic NVAF were enrolled. Blood samples were drawn within 72 h of admission, and we evaluated plasma levels of IL (interleukin)-1beta, TNF-alpha (tumour necrosis factor-alpha), IL-6, IL-10, E-selectin, P-selectin, ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1) and vWF (von Willebrand Factor). Subsequent patient events (stroke at follow-up) were monitored over a 3 year period. By multivariate analysis, only age, hypertension and high levels of IL-6, TNF-alpha and vWF remained significant predictors of a higher risk of experiencing ischaemic stroke at follow-up. Moreover, plasma values of TNF-alpha, IL-6 and vWF had a significant area under the ROC (receiver operating characteristic) curve. In conclusion, baseline plasma levels of TNF-alpha, IL-6 and vWF are predictors of new-onset ischaemic stroke at follow-up in patients with chronic NVAF.

Involvement of various neurotransmitters and neuromodulators have been shown to contribute to the ischemic injury and neuronal death associated with stroke Role of excitatory amino acid receptor activation, calcium overload, nitric oxide, and oxidative stress in the pathogenesis of ischemic brain damage is well established. Several new strategies are currently emerging, based on recent advances in our understanding of molecular pathways that could be considered as potential therapeutic targets. For example reactive oxygen species (ROS) are important contributors to the secondary injury cascade following traumatic brain injury (TBI), and ROS inhibition has consistently been shown to be neuroprotective following experimental TBI and brain ischemia. Furthermore, more recently, some authors concluded that nonanticoagulant 3K3A-APC exhibits greater neuroprotective efficacy with no risk for bleeding compared with drotrecogin-alfa activated, a hyperanticoagulant form of APC. Excessive calcium entry into depolarized neurons contributes significantly to cerebral tissue damage after ischemia. Included in the sequence of events leading to neuronal death in ischemic tissue following stroke is an excessive and toxic rise in the intracellular Ca(2+)-concentration, predominantly due to an influx of Ca2+ through nonselective cation-channels as well as Ca(2+)-channels.. Some authros conducted a study to investigate whether the enhancement of GABA receptor activity could inhibit NMDA receptor-mediated nitric oxide (NO) production by neuronal NO synthase (nNOS) in brain ischemic injury. The results showed that both the GABA(A) receptor agonist muscimol and the GABA(B) receptor agonist baclofen had neuroprotective effect, and the combination of two agonists could significantly protect neurons against death induced by ischemia/reperfusion. On this basis we conclude that neuroprotection for ischemic stroke refers to strategies, applied singly or in combination, that antagonize the injurious biochemical and molecular events that eventuate in irreversible ischemic injury. There has been a recent explosion of interest in this field, with over 1000 experimental papers and over 400 clinical articles appearing within the past 6 years. These studies, in turn, are the outgrowth of three decades of investigative work to define the multiple mechanisms and mediators of ischemic brain injury, which constitute potential targets of neuroprotection.