Domenico Di Raimondo

Inflammatory Cytokines in Acute Ischemic Stroke

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.

Twenty-four hour ambulatory blood pressure monitoring to evaluate effects on blood pressure of physical activity in hypertensive patients.

ObjectiveElevated blood pressure is an important risk factor for cardiovascular disease and stroke. Several studies have demonstrated that physical exercise reduces blood pressure levels in hypertensive subjects and improves control of several well-known risk factors for atherosclerosis such as diabetes mellitus, blood lipid profile and obesity. Our group attempted to evaluate if an exercise program based on periodic controlled fast walking sessions would reduce blood pressure levels in hypertensive subjects. DesignWe enrolled hypertensive subjects not suffering from obesity (Body Mass Index <30) already under pharmacological therapy; in these subjects we performed a six-week program of mobility exercise based on fast walking. SettingSecondary care. PatientsWe enrolled 189 subjects; 168 subjects completed the training period. Entry criteria were Stage I WHO hypertension in pharmacological treatment, BMI <30, and absence of any pathological condition resulting in reduced mobility. InterventionsA six-week mobility program centered on fast walking. Main Outcome MeasurementsSystolic and diastolic blood pressure levels before and after the walking program. ResultsMean 24 h systolic blood pressure changed from 143.1 to 135.5 mmHg. Mean 24 h diastolic blood pressure changed from 91.1 to 84.8 mmHg. ConclusionsThis reduction, evaluated with Ambulatory Blood Pressure Monitoring (ABPM), confirms that physical exercise should be a part of lifestyle changes for the management of hypertension both in untreated hypertensive patients or high-risk subjects for hypertension, and also for hypertensive patients in association with pharmacological therapy.

Migraine Headaches in Adolescents: A Student Population-Based Study in Monreale:

We assessed the prevalence of migraine headaches in an epidemiological survey of an 11 to 14-year-old student population. Migraine headaches were classified on the basis of questionnaires and neurological examination using the operational diagnostic criteria of the International Headache Society. Prevalence of migraine without aura (IHS code 1.1) was 2.35%; that of migraine with aura (IHS code 1.2) was 0.62%. Migraine without aura was equally distributed among males and females, whereas migraine with aura was preponderant in the female cohort. The prevalence of migraine headaches in males was constant through the ages studied, whereas the prevalence of migraine headaches in females reached a peak at age 12 and plateaued over the following two years. Although the new IHS classification criteria of migraines are reliable and exhaustive, some subcriteria may not be valid in a juvenile population. For instance, the duration of the pain in young migraineurs is often briefer than in adults, and the intensity of pain was almost always described as moderate or severe. Therefore, in order to increase the reliability and comprehensiveness of the IHS classification, minor modifications should be made.

Atherosclerosis as an Inflammatory Disease

In many ways, atherosclerosis is a chronic inflammatory disorder and this issue is confirmed by recent investigations of that have focused on inflammation, providing new insight into mechanisms of disease. Several recent studies have addressed the role of chemokines in leukocyte accumulation in atherosclerosis, extending our knowledge and understanding of the complex and cell type-specific functions of chemokines in atherosclerosis. Activated T-lymphocytes within the atherosclerotic vessel wall express the CD40 ligand surface molecule, known to play a major role in several immunological pathways. In addition to activated T-lymphocytes, functional CD40 and CD40L are coexpressed by human vascular endothelial cells, smooth muscle cells and human macrophages in vitro as well as in situ in human atherosclerotic lesions. Recent studies indicate that CD40L activates atheroma-associated cells by promoting the expression of molecules thought to be involved in atherosclerosis, such as adhesion molecules, cytokines, matrix metalloproteinases, and tissue factor. Atherosclerosis starts with an innate immune response involving the recruitment and activation of monocytes macrophages that respond to an excessive accumulation of modified lipids within the arterial wall, followed by an adaptive immune response involving antigen-specific T lymphocytes. Effector T cells recognize modified auto-antigens such as oxidized LDL and heat shock proteins (i.e. HSP-60) that are presented by antigen-presenting cells such as macrophages or dendritic cells. The accumulation of inflammatory cells within the arterial wall leads to local production of chemokines, interleukins and proteases that enhance the influx of monocytes and lymphocytes, thereby promoting the progression of atherosclerotic lesions Recent reports have helped explain some of these questions by pointing to a role of contact dependent interaction between CD40 and CD40 ligand (CD40L, renamed CD154) as a stimulus for atheroma-associated cells. Also Macrophages play important roles in the progression of atherosclerosis by exhibiting unique characteristics under the various stimuli, evolving the plaque instability, thrombus formation and remodeling. Macrophage recruitment by abnormal endothelium over developing atherosclerotic plaques, is aided by endothelial expression of adhesion molecules (ICAM-1, VCAM, ELAM). The knowledge of atherosclerosis as an inflammatory disease offers the opportunity to develop novel therapeutic strategies targeting the inflammatory component of the disease.

Inflammation in Ischemic Stroke Subtypes

Determining the cause of stroke does influence choices for management. categorization of subtypes of ischemic stroke has had considerable study, but definitions are hard to formulate and their application for diagnosis in an individual patient is often problematic. Cerebral ischemia initiates a complex cascade of events at genomic, molecular, and cellular levels, and inflammation is important in this cascade. In 1993 for For the Trial of Org 10172 in Acute Stroke Treatment (TOAST), Adams et al] conducted a placebo-controlled, randomized, blinded study of the low-molecular-weight heparinoid given to patients within 24 hours after stroke and developed a system for diagnosis of subtype of ischemic stroke that uses components of existing diagnostic schemes. The type of acute ischemic stroke was classified according to the TOAST classification: 1) Large Artery AtheroSclerosis (LAAS); 2) CardioEmbolic Infarct (CEI); 3) LACunar infarct (LAC); 4) stroke of Other Determined Etiology (ODE); 5) stroke of UnDetermined Etiology (UDE) (see Fig. (1)). On the basis of pathophysiologic differences of each stroke subtype its possible to hypothesize a different pattern of immuno-inflammatory activation in relation of ischemic stroke subtype. A nonspecific systemic inflammatory response occurs after both ischemic and hemorrhagic stroke, either as part of the process of brain damage or in response to complications such as deep venous thrombosis. Several studies have reported that higher levels of inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) are associated with worse outcome after ischemic stroke. Our group reported that patients with cardioembolic subtype showed significantly higher median plasma levels of TNF-α, IL-6, IL-1β whereas the lacunar subtype showed significantly lower median plasma levels of TNF-α, IL-6 and IL-1β. Our findings underlined the significant association was noted between the severity of neurological deficit at admission, the diagnostic subtype and some inflammatory variables.

Neuron Protection as a Therapeutic Target in Acute Ischemic Stroke

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.

Inflammation as a therapeutic target in acute ischemic stroke treatment.

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.

Transient topographical amnesia and cingulate cortex damage: a case report.

Transient topographical amnesia (TTA) is the temporary inability to find ones way in familiar or unfamiliar surroundings due to the inability to use well known environmental landmarks for route finding. The syndrome has not been described as having any obvious aetiology and has been thought to be caused by a vascular deficit in right hemispheric structures which are crucial for topographic recognition, i.e. parietal association and parahippocampal cortex. The patient described in the present study complained of several critical episodes of TTA and tonic rigidity of the left limbs. Neuropsychological assessment was normal except for a deficit in spatial memory tasks. Magnetic resonance (MR) imaging of the brain showed an angioma at the border of areas 24d and 23 of the right cingulate cortex. Because area 23 is strategically located in a network that links the parietal associative (area 7a) and parahippocampal cortices, and because these cortical areas are involved in topographical orienting processes, we suggest that a transient functional inactivation of the network caused by epileptic discharges spreading from the damaged cingulate cortex towards the parahippocampal and parietal association cortex could account for the spatial disorder. Similar discharges spreading from area 24d towards the primary motor cortex and/or the spinal cord could account for the episodes of tonic rigidity of the left limbs.

Immuno-inflammatory activation in acute cardio-embolic strokes in comparison with other subtypes of ischaemic stroke.

Few studies have examined the relationship between inflammatory biomarker blood levels, cardioembolic stroke subtype and neurological deficit. So the aim of our study is to evaluate plasma levels of immuno-inflammatory variables in patients with cardio-embolic acute ischaemic stroke compared to other diagnostic subtypes and to evaluate the relationship between immuno-inflammatory variables, acute neurological deficit and brain infarct volume. One hundred twenty patients with acute ischaemic stroke and 123 controls without a diagnosis of acute ischaemic stroke were evaluated. The type of acute ischaemic stroke was classified according to the TOAST classification. We evaluated plasma levels of IL-1beta, TNF-alpha, IL-6 and IL-10, E-selectin, P-selectin, sICAM-1,sVCAM-1, vWF, TPA and PAI-1. Patients with ischaemic stroke classified as cardio-embolic (CEI) showed, compared to other subtypes, significantly higher median plasma levels of TNF-alpha , IL-6 and IL-1beta. Furthermore stroke patients classified as lacunar showed, compared to other subtypes, significantly lower median plasma levels of TNF-alpha, IL-6 and IL-1beta. Multiple linear regression showed a significant association between the Scandinavian Stroke Scale (SSS) score at admission and diagnostic subtype, infarct volume of cardio-embolic strokes and some inflammatory variables. Our findings confirm that cardio-embolic strokes have a worse clinical presentation and produce larger and more disabling strokes than other ischaemic stroke subtypes reporting a possible explanation of higher immuno-inflammatory activation of the acute phase.

Migraine headaches in adolescents: A five-year follow-up study

Background and Objectives.—Longitudinal studies of juvenile migraine are very few. We investigated the prevalence and evolution over 5 years of migraine without aura (MWOA) and migraineous disorder (MD) in an adolescent population.