987 resultados para ischemic preconditioning


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Purpose: Previous studies of the visual outcome in bilateral non-arteritic anterior ischemic optic neuropathy (NAION) have yielded conflicting results, specifically regarding congruity between fellow eyes. Prior studies have used measures of acuity and computerized perimetry but none has compared Goldmann visual field outcomes between fellow eyes. In order to better define the concordance of visual loss in this condition, we reviewed our cases of bilateral sequential NAION, including measures of visual acuity, pupillary function and both pattern and severity of visual field loss.Methods: We performed a retrospective chart review of 102 patients with a diagnosis of bilateral sequential NAION. Of the 102 patients, 86 were included in the study for analysis of final visual outcome between the affected eyes. Visual function was assessed using visual acuity, Goldmann visual fields, color vision and RAPD. A quantitative total visual field score and score per quadrant was analyzed for each eye using the numerical Goldmann visual field scoring method previously described by Esterman and colleagues. Based upon these scores, we calculated the total deviation and pattern deviation between fellow eyes and between eyes of different patients. Statistical significance was determined using nonparametric tests.Results: A statistically significant correlation was found between fellow eyes for multiple parameters, including logMAR visual acuity (P = 0.0101), global visual field (P = 0.0001), superior visual field (P = 0.0001), and inferior visual field (P = 0.0001). In addition, the mean deviation of both total (P = 0.0000000007) and pattern (P = 0.000000004) deviation analyses was significantly less between fellow eyes ("intra"-eyes) than between eyes of different patients ("inter"-eyes).Conclusions: Visual function between fellow eyes showed a fair to moderate correlation that was statistically significant. The pattern of vision loss was also more similar in fellow eyes than between eyes of different patients. These results may help allow better prediction of visual outcome for the second eye in patients with NAION. These findings may also be useful for evaluating efficacy of therapeutic interventions.

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Brain infarction of unknown cause, known as cryptogenic stroke, represents 30% to 40% of all ischemic strokes, or approximately 400,000 cases each year in western Europe. In this category of patients new potential causes, such as aortic arch atheroma in the elderly, have been investigated in the past two decades.

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BACKGROUND AND PURPOSE: Onset-to-reperfusion time (ORT) has recently emerged as an essential prognostic factor in acute ischemic stroke therapy. Although favorable outcome is associated with reduced ORT, it remains unclear whether intracranial bleeding depends on ORT. We therefore sought to determine whether ORT influenced the risk and volume of intracerebral hemorrhage (ICH) after combined intravenous and intra-arterial therapy. METHODS: Based on our prospective registry, we included 157 consecutive acute ischemic stroke patients successfully recanalized with combined intravenous and intra-arterial therapy between April 2007 and October 2011. Primary outcome was any ICH within 24 hours posttreatment. Secondary outcomes included occurrence of symptomatic ICH (sICH) and ICH volume measured with the ABC/2. RESULTS: Any ICH occurred in 26% of the study sample (n=33). sICH occurred in 5.5% (n=7). Median ICH volume was 0.8 mL. ORT was increased in patients with ICH (median=260 minutes; interquartile range=230-306) compared with patients without ICH (median=226 minutes; interquartile range=200-281; P=0.008). In the setting of sICH, ORT reached a median of 300 minutes (interquartile range=276-401; P=0.004). The difference remained significant after adjustment for potential confounding factors (adjusted P=0.045 for ICH; adjusted P=0.002 for sICH). There was no correlation between ICH volume and ORT (r=0.16; P=0.33). CONCLUSIONS: ORT influences the rate but not the volume of ICH and appears to be a critical predictor of symptomatic hemorrhage after successful combined intravenous and intra-arterial therapy. To minimize the risk of bleeding, revascularization should be achieved within 4.5 hours of stroke onset.

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ABSTRACT: Excitotoxicity and cerebral ischemia induce strong endocytosis in neurons, and we here investigate its functional role in neuroprotection by a functional transactivator of transcription (TAT)-peptide, the c-Jun N-terminal kinase (JNK) inhibitor D-JNKI1, against NMDA-excitotoxicity in vitro and neonatal ischemic stroke in P12 Sprague-Dawley rats. In both situations, the neuroprotective efficacy of D-JNKI1 was confirmed, but excessively high doses were counterproductive. Importantly, the induced endocytosis was necessary for neuroprotection, which required that the TAT-peptide be administered at a time when induced endocytosis was occurring. Uptake by other routes failed to protect, and even promoted cell death at high doses. Blocking the induced endocytosis of D-JNKI1 with heparin or with an excess of D-TAT-peptide eliminated the neuroprotection. We conclude that excitotoxicity-induced endocytosis is a basic property of stressed neurons that can target neuroprotective TAT-peptides into the neurons that need protection. Furthermore, it is the main mediator of neuroprotection by D-JNKI1. This may explain promising reports of strong neuroprotection by TAT-peptides without apparent side effects, and warns that the timing of peptide administration is crucial.

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Following acute myocardial infarction, necrotic cardiac tissue is replaced by scar leading to ventricular remodeling and pump failure. Transplantation of autologous bone marrow-derived cells into the heart, early post-infarct, aims to prevent ventricular remodeling. This strategy has been evaluated in four controlled, randomized clinical trials, which provided mixed results. A transient improvement in ventricular function was observed in one trial, and a modest improvement (the duration of which remains to be determined) in an additional trial, whereas two trials showed negative results. A modest benefit of bone marrow cell transplantation was also observed in patients with chronic ischemic heart disease. Despite mixed results reported so far, cell therapy of heart disease still is in its infancy and has considerable room for improvement.

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INTRODUCTION: The aim of this study was to assess the blood flow in the feet before and after lower limb revascularization using laser Doppler imaging (LDI). METHODS: Ten patients with critical lower limb ischemia were prospectively enrolled from June to October 2004. All patients underwent successful unilateral surgical interventions including above-knee bypass, distal bypass and endarterectomy. Skin blood flow (SBF) over the plantar surface of both forefeet and heels was measured by LDI 24h before and 10 days after revascularization, expressed in perfusion units (PU), and reported as mean+/-SD. RESULTS: Measurements in the forefoot and heel were similar. Before revascularization mean SBF was significantly lower in the ischemic foot (130+/-71 PU) compared to the contralateral foot (212+/-68 PU), p<0.05. After revascularization a significant increase of the SBF in the forefoot (from 135+/-67 to 202+/-86 PU, p=0.001) and hindfoot (from 148+/-58 to 203+/-83, p=0.001) was observed on the treatment side. However, a large decrease of the SBF was seen in forefoot and hindfoot on the untreated side (from 250+/-123 PU to 176+/-83 and from 208+/-116 to 133+/-40, p=0.001, respectively). CONCLUSION: This study confirms the benefits of revascularization in patients with nonhealing foot lesions due to critical limb ischemia. A significant increase of the SBF was observed on the treatment side. However, an unexpected decrease was observed on the untreated side.

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In 2011 several articles seemed significant for the practice of general medicine. Diagnosis of hypertension needs several measurements and may need 24-hour ambulatory blood pressure monitoring. Glycosylated hemoglobin is a reliable tool to diagnose diabetes mellitus. The ABCD2 score with neurological imaging help the triage of transient ischemic attacks. Pulmonary embolism can be treated as outpatient for low risk patients. Gluten-free diet may be tried in irritable bowel syndrome. Nitrofurantoin is a reasonable alternative for simple urinary tract infection in women, but antibiotics are not needed after drainage of an uncomplicated skin abscess. Subclinical thyroid dysfunction is a risk factor of osteoporosis in older men. Sequential use of MMSE and ACE scores is a promising approach to assess medical decision-making capacity.

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Objective: Cooling is considered a panacea in burn injury. However, burn injuries are characterized by an ischemic zone prone to progression, a phenomenon that can substantially increase morbidity. Cold-induced vasoconstriction potentially aggravates ischemia and promotes progression. Therefore we compared the effect of warm (37°C) and cold (17°C) water on burn progression. Methods: The comb burn model creates 4 rectangular burned surfaces separated by 3 unburned interspaces that become necrotic if untreated. After heating in boiling water the template was applied for 60 seconds on 24 Wistar rats randomized into 3 groups: no treatment (CON); treatment for 20 minutes with cold water (17°C: CW) or warm water (37°C: WW). Burn progression in surface (planimetry) and Departmenth (histology), as well as microcirculatory perfusion (laser Doppler flowmetry) were assessed after 1h, as well as 1, 4, and 7 days. Results: Both CW and WW delayed burn progression without reducing the final burn Departmenth (deep dermis). In contrast, only WW but not CW increased dermal perfusion (81 ± 2% (WW) vs. 62 ± 2% (CW) and 63 ± 1% (CON), p< 0·05) already 1 hour after burn induction. The difference observed after one hour led to a complete flow recovery during the observation period and translated into increased interspace survival, respectively less necrosis with WW(65 ± 4% vs. 81 + 4% (CW) and 91 ± 2% (CON), p< 0·05) after 7 days. Conclusions: Application of warm water significantly improved dermal perfusion, increased interspace survival, and delayed burn progression.However it didn't alter the ultimate burn Departmenth of the actually burned area. Therefore, warm water can create a therapeutic window for targeted nonsurgical treatment of burn progression.

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Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69-0.82; P = 4.46 × 10(-10)), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10(-3); combined P = 1.00 × 10(-11)). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions.

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BACKGROUND AND PURPOSE: Intravenous thrombolysis for acute ischemic stroke is beneficial within 4.5 hours of symptom onset, but the effect rapidly decreases over time, necessitating quick diagnostic in-hospital work-up. Initial time strain occasionally results in treatment of patients with an alternate diagnosis (stroke mimics). We investigated whether intravenous thrombolysis is safe in these patients. METHODS: In this multicenter observational cohort study containing 5581 consecutive patients treated with intravenous thrombolysis, we determined the frequency and the clinical characteristics of stroke mimics. For safety, we compared the symptomatic intracranial hemorrhage (European Cooperative Acute Stroke Study II [ECASS-II] definition) rate of stroke mimics with ischemic strokes. RESULTS: One hundred stroke mimics were identified, resulting in a frequency of 1.8% (95% confidence interval, 1.5-2.2). Patients with a stroke mimic were younger, more often female, and had fewer risk factors except smoking and previous stroke or transient ischemic attack. The symptomatic intracranial hemorrhage rate in stroke mimics was 1.0% (95% confidence interval, 0.0-5.0) compared with 7.9% (95% confidence interval, 7.2-8.7) in ischemic strokes. CONCLUSIONS: In experienced stroke centers, among patients treated with intravenous thrombolysis, only a few had a final diagnosis other than stroke. The complication rate in these stroke mimics was low.

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INTRODUCTION: Panarteritis nodosa (PAN) is a systemic vasculitis affecting small and medium-sized arteries. Neuro-ophthalmological complications of PAN are rare but numerous, and may affect the eye, the visual and the oculomotor pathways. Such complications occur mainly in patients previously diagnosed with PAN. OBSERVATION: A 51-year-old woman presented with an isolated right trochlear (IV) palsy, in the setting of headaches and fluctuating fever of unknown etiology. Erythrocyte sedimentation rate was 13 mm and full blood cell count was normal. Previous chest X-ray and blood studies were negative for an infection or inflammation. Orbital and cerebral CT scan was normal. Spontaneous recovery of diplopia ensued over four days. Two days later, paresthesia and sensory paresis of the dorsal portion of the left foot were present. Lumbar puncture revealed 14 leucocytes (76 percent lymphocytes) with elevated proteins, but blood studies and serologies were negative. A diagnosis of undetermined meningo-myelo-radiculoneuritis was made. Because of a possible tick bite six weeks previously the patient was empirically treated with 2 g intravenous ceftriaxone for 3 weeks. Fever rapidly dropped. Six weeks after the onset of diplopia, acute onset of blindness in her right eye, diffuse arthralgias and fever motivated a new hospitalization. There was a central retinal artery occlusion of the right eye. Blood studies now revealed signs of systemic inflammation (ESR 30 mm, CRP 12 mg/L, ANA 1/80, pANCA 1/40, leucocytosis 12.4 G/L, Hb 111 g/L, Ht 33 percent). Biopsy of the left sural nerve revealed arterial fibrinoid necrosis. A diagnosis of PAN was made. CONCLUSIONS: Transient diplopia can be the heralding symptom of a systemic vasculitis such as PAN, giant cell arteritis and Wegener granulomatosis. In this patient the presence of accompanying systemic symptoms raised a suspicion of systemic inflammation, but the absence of serologic and imaging abnormalities precluded a specific diagnosis initially. A few weeks later, the presence of a second ischemic event (retinal) and positive blood studies led to a further diagnostic procedure. Oculomotor and abducens palsies have rarely been reported in association with PAN. We report the first case of trochlear nerve paresis as the inaugural neurological sign of PAN. This case highlights the importance of considering inflammatory systemic disorders in patients with acute diplopia particularly when they are young, lack vascular risk factors or cause, and complain of associated systemic symptoms.

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The benefit of induced hyperventilation for intracranial pressure (ICP) control after severe traumatic brain injury (TBI) is controversial. In this study, we investigated the impact of early and sustained hyperventilation on compliances of the cerebral arteries and of the cerebrospinal (CSF) compartment during mild hyperventilation in severe TBI patients. We included 27 severe TBI patients (mean 39.5 ± 3.4 years, 6 women) in whom an increase in ventilation (20% increase in respiratory minute volume) was performed during 50 min as part of a standard clinical CO(2) reactivity test. Using a new mathematical model, cerebral arterial compliance (Ca) and CSF compartment compliance (Ci) were calculated based on the analysis of ICP, arterial blood pressure, and cerebral blood flow velocity waveforms. Hyperventilation initially induced a reduction in ICP (17.5 ± 6.6 vs. 13.9 ± 6.2 mmHg; p < 0.001), which correlated with an increase in Ci (r(2) = 0.213; p = 0.015). Concomitantly, the reduction in cerebral blood flow velocities (CBFV, 74.6 ± 27.0 vs. 62.9 ± 22.9 cm/sec; p < 0.001) marginally correlated with the reduction in Ca (r(2) = 0.209; p = 0.017). During sustained hyperventilation, ICP increased (13.9 ± 6.2 vs. 15.3 ± 6.4 mmHg; p < 0.001), which correlated with a reduction in Ci (r(2) = 0.297; p = 0.003), but no significant changes in Ca were found during that period. The early reduction in Ca persisted irrespective of the duration of hyperventilation, which may contribute to the lack of clinical benefit of hyperventilation after TBI. Further studies are needed to determine whether monitoring of arterial and CSF compartment compliances may detect and prevent an adverse ischemic event during hyperventilation.

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Persistent pulmonary hypertension of the newborn (PPHN) is a life threatening condition associated with an increased risk of neurodevelopmental impairment. The recommended treatment for this condition is inhaled nitric oxide (iNO) and has been used in our Neonatal Intensive Care Unit since 1998. We prospectively offered neurodevelopmental follow-up to children treated with iNO for PPHN, including extensive neurological evaluation, developmental/cognitive evaluation at 18 months and 3.5-5 years old, and evaluated the rate of severe and moderate handicap and normal neurodevelopmental outcome, compared to a control group and the literature. Population consisted of 29 patients treated only with iNO, born between 01.01.1999 and 31.12.2005 (study group), and 32 healthy term infants born in 1998 in our maternity (control group). During those seven years, 65 infants were admitted in our Unit with PPHN, of whom 40 were treated with iNO alone. 34 children survived (85%) and were offered neurodevelopmental follow-up, 7 children were lost to follow-up due to various reasons. 22 children were examined at the age of 18 months (76%) with a rate of moderate handicap of 22% (2 with expressive language delay, 2 with difficult behavior, and 1 child with moderate hearing loss), and a rate of major handicap of 4.5% (1 child with cerebral palsy due to perinatal stroke, and moderate hearing loss). At preschool age, 17 (50%) were examined, the rate of moderate handicap was 22% (4 borderline intelligence, 1 hearing loss), and the rate of major handicap was 4.5% (one child with cerebral palsy and hearing loss), compared to 26.9% and 0% in the control group. Mean developmental quotient at 18 months was 100.3 ± 8.7 (control group 118.3), and at preschool age mean cognitive indices were within normal limits for the 2 tests performed at 3.5 or 5 years (108 ± 21, 94.4 ± 17). Most of the children with a less favorable neurodevelopmental outcome suffered from birth asphyxia (ruptured uterus, placental abruption, maternal hypotension, diabetic cardiomyopathy), and notably, the 2 children with sensorineural hearing loss both suffered from severe hypoxic-ischemic enkelopathy. Treatment with iNO was not the direct cause of the neurodevelopmental impairments observed in children treated for PPHN.

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BACKGROUND: Sclera is a very radioresistant tissue and scleritis after proton therapy has not been described so far. HISTORY AND SIGNS: Four female patients, aged between 31 and 74 years, were treated with proton therapy for uveal melanoma (height range: 2.2 - 3.5 mm), located in the macula, the superior equator and 2 in the ciliary body. All patients had a history of a previous or active inflammatory disease and developed scleritis after radiotherapy. THERAPY AND OUTCOME: Two patients had infectious scleritis and were treated with adequate antibiotic therapy. After systemic corticotherapy, 3 patients recovered completely; the remaining patient was managed with additional immunosuppressive treatment as well as a conjunctival and scleral graft, but has not become pain free yet. CONCLUSION: Scleritis is a possible complication after proton therapy, probably on an ischemic basis, where there is a predisposing factor such as inflammatory systemic disease.

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AIM: The aim of this case report was to show the importance to research metabolic etiology, especially a carnitine deficiency in dilated cardiomyopathy of children. CASE REPORT: A three years old Togolese child presented muscular hypotonia, dyspnea. Examination showed left galop murmur and systolic murmur 2/6. Chest X-ray showed cardiomegaly (CTI: 0.66), electrocardiogram, a sinusal rythm, left ventricle hypertrophy and T wave abnormalities. Echocardiogram showed a markedly dilated left ventricle with reduced systolic function (EF: 0.43; reference range 0.55-0.80) and moderate mitral regurgitation. The inflammatory signs where negatives. Magnetic resonance imaging don't show signs of ischemic or myocarditis. The levels of free and total plasmatic carnitine decreased: 3μmol/L (N: 18-48μmol/L) and 5μmol/l (N: 29-70μmol/L) respectively. Mutation analysis of the gene SLC22A5 confirms the diagnosis of primary systemic carnitine deficiency. Treatment with oral carnitine was started at 200mg/kg per day. Within three weeks of treatment, we observed the decrease of all symptoms and the left ventricular size and function normalized (EF: 0.62). He has now been on oral carnitine for live. CONCLUSION: Primary carnitine deficiency is a cause of dilated cardiomyopathy in child. It must systematically be suspected when a child presents a primitive cardiomyopathy. The treatment with oral carnitine for live is simple, with excellent prognosis.