Endogenous protease nexin-1 protects against cerebral ischemia.

The serine protease thrombin plays a role in signalling ischemic neuronal death in the brain. Paradoxically, endogenous neuroprotective mechanisms can be triggered by preconditioning with thrombin (thrombin preconditioning, TPC), leading to tolerance to cerebral ischemia. Here we studied the role of thrombin's endogenous potent inhibitor, protease nexin-1 (PN-1), in ischemia and in tolerance to cerebral ischemia induced by TPC. Cerebral ischemia was modelled in vitro in organotypic hippocampal slice cultures from rats or genetically engineered mice lacking PN-1 or with the reporter gene lacZ knocked into the PN-1 locus PN-1HAPN-1-lacZ/HAPN-1-lacZ (PN-1 KI) exposed to oxygen and glucose deprivation (OGD). We observed increased thrombin enzyme activity in culture homogenates 24 h after OGD. Lack of PN-1 increased neuronal death in the CA1, suggesting that endogenous PN-1 inhibits thrombin-induced neuronal damage after ischemia. OGD enhanced β-galactosidase activity, reflecting PN-1 expression, at one and 24 h, most strikingly in the stratum radiatum, a glial cell layer adjacent to the CA1 layer of ischemia sensitive neurons. TPC, 24 h before OGD, additionally increased PN-1 expression 1 h after OGD, compared to OGD alone. TPC failed to induce tolerance in cultures from PN-1(-/-) mice confirming PN-1 as an important TPC target. PN-1 upregulation after TPC was blocked by the c-Jun N-terminal kinase (JNK) inhibitor, L-JNKI1, known to block TPC. This work suggests that PN-1 is an endogenous neuroprotectant in cerebral ischemia and a potential target for neuroprotection.

Diagnosis and management of blunt great vessel trauma.

Traditionally, thoracic aortic rupture, suspected after blunt thoracic trauma, is characterized by a chest radiograph showing a widened mediastinum. The diagnostic machinery consecutively activated still depends heavily on the pressure as additional traumatic lesions. A patient with additional cranio-cerebral trauma would typically undergo contrast-enhanced computed tomography or magnetic resonance imaging of head, chest, and other regions. In a number of patients these analyses would confirm the presence of blood in the mediastinum without formal proof of an aortic disruption. This is because mediastinal hematomas may be caused not only by an aortic rupture, but also by numerous other blood sources including fractures of the spine and other macro- and microvascular lesions providing similar images. Therefore, aortic angiography became our preferred diagnostic tool to identify or rule out acute traumatic lesions of not only the aorta but with great vessels. However recently, a number of traumatic aortic transsections have been identified by transoesophageal echocardiography (TEE). TEE has the additional advantage of being a bed-side procedure providing additional information about cardiac function. The latter analysis allows for identification and quantification of cardiac contusions, post-traumatic myocardial infarctions, and valvar lesions which are of prime importance to develop an adequate surgical strategy and to assess the risk of the numerous emergency procedures required in patients with polytrauma. The standard approach for repair of isthmic aortic rupture is through a lateral thoracotomy. Distal and proximal control of the aorta can be achieved in a substantial number of cases before complete aortic rupture occurs and a higher proportion of direct suture repair can be achieved under such circumstances. Most proximal descending aortic procedures are performed without cardiopulmonary bypass (clamp and go) but paraplegia may occur before, during, or after the procedure. Ascending aortic lesions and disruption of the aortic arch, the supra-aortic vessels, the main pulmonary arteries, the great veins as well as cardiac lesions are best approached through a sternotomy, which may have to be extended. Cardiopulmonary bypass allowing for deep hypothermia and circulatory arrest is often required and carries its own complications. It is not clear whether the increasing proportion of ascending aortic and cardiac lesions which are observed nowadays are due to a change in trauma mechanics (i.e., speed limits, seat belts, air-bags), an improvement of the diagnostic tools or both.

Memòria, reorganització cerebral evidenciada amb fMRI i hipocamp

Aquesta pretén ser una revisió general dels processos cognitius normals i de la capacitat de reorganització cerebral en cas de dany cerebral adquirit (lesions i malalties neurodegeneratives).

Routine use of intravascular ultrasound for endovascular aneurysm repair: angiography is not necessary.

INTRODUCTION: to assess the outcome of endovascular aortic aneurysm repair (EVAR) using intravascular ultrasound (IVUS) without angiography. MATERIALS/METHODS: eighty consecutive patients (median age 69 years (range 25-90): male 72 (90%), female 8 (10%)) underwent endovascular aneurysm repair (AAA 68 (85%), TAA 12 (15%)) using either angiography in 31/80 patients (39%) or IVUS in 49/80 patients (61%) in accordance to the surgeons preference. RESULTS: hospital mortality was 2/80 (3%), 1/68 for AAA (2%), 1/12 for TAA (8%), 2/31 for angiography (7%), and 0/49 for IVUS (0.0%: NS). Median quantity of contrast medium was 190 ml (range: 20-350) for angiography versus 0 ml for IVUS (p<0.01). Median X-ray exposure time 24 min (range 9-65 min) versus 8 min (range 0-60 min) for IVUS (p<0.05). No coverage of renal or suprarenal artery orifices occurred in either group. Conversion to open surgery was necessary in 4/80 patients (5%), 1/31 for angiography (3%) and 3/49 patients for IVUS (6%: NS). Early endoleaks were observed in 13/80 patients (16%): 8/31 patients for angiography (26%) versus 5/49 for IVUS (10%: p<0.05): 5/13 endoleaks resolved spontaneously (39%) whereas 8/13 (61%) required additional procedures. CONCLUSIONS: IVUS is a reliable tool for EVAR. In most cases, perprocedural angiography is not necessary.

Impact of bulk cardiac motion on right coronary MR angiography and vessel wall imaging.

The purpose of this study was to investigate the impact of in-plane coronary artery motion on coronary magnetic resonance angiography (MRA) and coronary MR vessel wall imaging. Free-breathing, navigator-gated, 3D-segmented k-space turbo field echo ((TFE)/echo-planar imaging (EPI)) coronary MRA and 2D fast spin-echo coronary vessel wall imaging of the right coronary artery (RCA) were performed in 15 healthy adult subjects. Images were acquired at two different diastolic time periods in each subject: 1) during a subject-specific diastasis period (in-plane velocity <4 cm/second) identified from analysis of in-plane coronary artery motion, and 2) using a diastolic trigger delay based on a previously implemented heart-rate-dependent empirical formula. RCA vessel wall imaging was only feasible with subject-specific middiastolic acquisition, while the coronary wall could not be identified with the heart-rate-dependent formula. For coronary MRA, RCA border definition was improved by 13% (P < 0.001) with the use of subject-specific trigger delay (vs. heart-rate-dependent delay). Subject-specific middiastolic image acquisition improves 3D TFE/EPI coronary MRA, and is critical for RCA vessel wall imaging.

Automated identification of minimal myocardial motion for improved image quality on MR angiography at 3 T

OBJECTIVE: Imaging during a period of minimal myocardial motion is of paramount importance for coronary MR angiography (MRA). The objective of our study was to evaluate the utility of FREEZE, a custom-built automated tool for the identification of the period of minimal myocardial motion, in both a moving phantom at 1.5 T and 10 healthy adults (nine men, one woman; mean age, 24.9 years; age range, 21-32 years) at 3 T. CONCLUSION: Quantitative analysis of the moving phantom showed that dimension measurements approached those obtained in the static phantom when using FREEZE. In vitro, vessel sharpness, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were significantly improved when coronary MRA was performed during the software-prescribed period of minimal myocardial motion (p < 0.05). Consistent with these objective findings, image quality assessments by consensus review also improved significantly when using the automated prescription of the period of minimal myocardial motion. The use of FREEZE improves image quality of coronary MRA. Simultaneously, operator dependence can be minimized while the ease of use is improved.

Demographic and clinical predictors of leptomeningeal collaterals in stroke patients.

BACKGROUND: Leptomeningeal collaterals improve outcome after stroke, including reduction of hemorrhagic complications after thrombolytic or endovascular therapy, smaller infarct size, and reduction in symptoms at follow-up evaluation. The purpose of this study was to determine the demographic and clinical variables that are associated with a greater degree of cerebral collaterals. METHODS: Clinical data of patients presenting with M1 occlusions of the middle cerebral artery (MCA) and associated computed tomography angiography studies after admission from 3 separate institutions were retrospectively compiled (n = 82). Occluded hemispheres were evaluated against the intact hemisphere for degree of collateralization in the MCA territory. Regression analysis of variance was conducted between clinical variables and collateral score to determine which variables associate with greater collateral development. RESULTS: Smaller infarct size corresponded to greater collateral scores, whereas older age and statin use corresponded to lower collateral scores (P < .001). CONCLUSIONS: Cerebral collateralization is influenced by age and statin use and influences infarct size.

Intraarterial nimodipine for the treatment of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage: a preliminary study.

OBJECTIVE: Despite dramatic advances in all medical era, cerebral vasospasm is still the major complication in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to assess the influence of intraarterial (IA) nimodipine in the treatment of symptomatic vasospasm and in preventing neurological disabilities. MATERIALS AND METHODS: We retrospectively reviewed 10 patients of SAH who received IA nimodipine in 15 procedures. The decision to perform angiography and endovascular treatment was based on the neurological examination, brain computed tomography (CT) and CT-angiography. The procedure reports, anesthesia records, neurological examination before and after the procedure, brain imaging and short- and long-term outcome were studied. RESULTS: The average dose of nimodipine was 2 mg. The median change in mean arterial pressure at 10 min was -10 mmHg. No significant change of heart rate was observed at 10 min. There was radiological improvement in 80% of the procedures. Neurological improvement was noted after eight out of 12 procedures when nimodipine was used as the sole treatment and after 10 out of 15, overall. Six patients clinically improved after the treatment and had good outcome. In one patient, an embolus caused fatal anterior and middle cerebral arteries infarction. There was no other neurological deficit or radiological abnormality due to the nimodipine treatment itself. CONCLUSION: Low-dose IA nimodipine is a valid adjunct for the endovascular treatment of cerebral vasospasm. Beneficial effects are achieved in some patients, prompting a prospective control study.

La inclusió dels alumnes amb paràlisi cerebral, una mirada des de la teràpia ocupacional

Aquest és un projecte d'investigació descriptiva. Té com a finalitat conèixer i comprendre com és la inclusió dels nens amb Paràlisis Cerebral a les escoles ordinàries (bressol, primària i secundària), de la ciutat de Barcelona, des de la mirada de la Teràpia Ocupacional. Per tant, primer s'ha d'investigar quants alumnes amb aquesta lesió estan inclosos en escoles ordinàries, com també conèixer quants alumnes tornen a l'escola especial després d'estar escolaritzats a la ordinària. D'altra banda, es pretén descriure les perspectives i percepcions dels professionals i els alumnes implicats a la inclusió, i què succeeix a l'escola ordinària perquè alguns alumnes hagin de tornar a l'especial en algun moment de la seva escolarització. El projecte és de caire qualitatiu, on els instruments per l'obtenció de dades són protocols d'observació, entrevistes semi- estructurades i enquestes. Encara que per obtenir la mostra i els participants s'utilitzaran tècniques quantitatives. Les limitacions de l'estudi seran aquelles escoles, professionals i alumnes que per motius personals no vulguin participar de la mostra.

La teràpia assistida amb gossos: una eina terapèutica en el tractament de la fisioteràpia en ens amb paràlisi cerebral espàstica

La Teràpia Assistida amb Animals (TAA) mostra antecedents des del segle XX utilitzant diversos animals amb finalitats terapèutiques, però en realitat, hi ha pocs estudis sobre els beneficis de la TAA. Si partim de que hi ha poca informació i recerca en la globalitat d‟aquest tipus de teràpia s‟ha de dir que la recerca clínica de La Teràpia Assistida amb Gossos en l‟àmbit de Rehabilitació Pediàtrica en Fisioteràpia és un món per descobrir. L‟estudi i investigació de “La Teràpia Assistida amb gossos: una eina terapèutica en el tractament de Fisioteràpia en nens amb Lesió Cerebral Espàstica” v ol mostrar de manera qualitativa els beneficis que pot duu a terme aquesta tipologia de treball mitjançant el gos com a eina motivadora en el tractament de Fisioteràpia. L‟estudi consta d‟un grup mostra de 4 nens amb Lesió Cerebral Espàstica que realitzaran un tractament amb Teràpia Assistida amb Gossos d‟un curs de durada, realitzant una sessió per setmana de manera individual on l‟objectiu serà treballar la Rehabilitació Física mitjançant diverses tipologies d‟exercicis enfocades a millorar el control cefàlic, fomentar el control del to muscular , afavorir la bipedestació i/o marxa i estimular la motricitat fina. El recull es farà qualitativament mitjançant diari de camp i visionats d‟imatges.

A realistic Computed Tomography simulator for small motion analysis of cerebral aneurysms.

This paper describes a realistic simulator for the Computed Tomography (CT) scan process for motion analysis. In fact, we are currently developing a new framework to find small motion from the CT scan. In order to prove the fidelity of this framework, or potentially any other algorithm, we present in this paper a simulator to simulate the whole CT acquisition process with a priori known parameters. In other words, it is a digital phantom for the motion analysis that can be used to compare the results of any related algorithm with the ground-truth realistic analytical model. Such a simulator can be used by the community to test different algorithms in the biomedical imaging domain. The most important features of this simulator are its different considerations to simulate the best the real acquisition process and its generality.

Anterior Segment Angiography in Strabismus Surgery

Background: Anterior ciliary arteries travelling along recti muscles provide anterior segment vascularization, which can be compromised by surgery involving more than 2 muscles.Patients and Methods: We studied retrospectively the files of 10 patients in whom a fluorescein angiography of the iris had been performed as a pre-operative assessment prior to a second or third oculomotor surgery.Results: The median age of the patients was 47.5 years (range 15 to 73 years). Relative iris ischemia was present in 4 patients following multiple surgeries, none of them presenting any general cardiovascular risk. The initial surgical protocol was modified according to angiographic results in these 4 patients.Conclusion: When further surgery has to be performed on previously multi-operated patients, anterior segment angiography can be useful in the planning of surgery in order to minimize the risks of anterior segment ischemia.

Evolution of the neurochemical profile after transient focal cerebral ischemia in the mouse brain.

Evolution of the neurochemical profile consisting of 19 metabolites after 30 mins of middle cerebral artery occlusion was longitudinally assessed at 3, 8 and 24 h in 6 to 8 microL volumes in the striatum using localized 1H-magnetic resonance spectroscopy at 14.1 T. Profound changes were detected as early as 3 h after ischemia, which include elevated lactate levels in the presence of significant glucose concentrations, decreases in glutamate and a transient twofold glutamine increase, likely to be linked to the excitotoxic release of glutamate and conversion into glial glutamine. Interestingly, decreases in N-acetyl-aspartate (NAA), as well as in taurine, exceeded those in neuronal glutamate, suggesting that the putative neuronal marker NAA is rather a sensitive marker of neuronal viability. With further ischemia evolution, additional, more profound concentration decreases were detected, reflecting a disruption of cellular functions. We conclude that early changes in markers of energy metabolism, glutamate excitotoxicity and neuronal viability can be detected with high precision non-invasively in mice after stroke. Such investigations should lead to a better understanding and insight into the sequential early changes in the brain parenchyma after ischemia, which could be used for identifying new targets for neuroprotection.

Correlations between negative-induced cerebral dynamics and idiopathic intellectual disability: an EEG study

Intellectual disability has long been associated with deficits in socio-emotional processing. However, studies investigating brain dynamics of maladaptive socio-emotional skills associated with intellectual disability are scarce. Here, we compared differences in brain activity between low intelligence quotient (I.Q.<75, N=13) and normal controls (N=15) while evaluating their subjective emotions. Positive (P) and negative (N) valenced pictures were presented one at a time to participants of both groups, at a rate of ¾. The task required that each participant evaluate their subjective emotion and press a predefined push-button when done, alternatively P and N. Electroencephalographic (EEG) signals were continuously recorded, and the 1000ms time window following each picture was analyzed offline for power in frequency domain. Alpha low (8-10Hz) and upper (10-13Hz) frequency bands were then compared for both groups and for both P and N emotions in 12 distributed scalp electrodes. The qualitative evaluation of emotions was similar between both groups, with constant longer reaction times for the low IQ participants. The EEG signal comparison shows marked power decrease in upper alpha frequency range for N emotions in low intelligence group. Otherwise no significant difference was noticed between low and normal IQ. Main findings of the present study are (1) results do not support the hypothesis that impairment in developmental intelligence roots in maladaptive emotional processing; (2) the strong alpha power suppression during negative-induced emotions suggests the involvement of an extended neural network and more effortful inhibition processes than positive ones. We call for further studies with a larger sample.