985 resultados para microvascular obstruction
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Objectives: This study analyses the long term cardiac and neurological outcome of patients with cardiac rhabdomyoma (CR) in order to allow comprehensive prenatal counselling. Because of the relative rarity of the disease, there is paucity of data concerning the outcome of patients with CR. Methods: A retrospective study including all cases with echocardiographic diagnosis of CR encountered between April 1986 and August 2006. Results: Of 24 CR patients identified, 7 were diagnosed in-utero at a gestational age (GA) between 28-35 weeks and 17 postnatally between 10 days and 5 years. 14 had multiple CR and 10 had one/two CR. The CRs were situated predominantly in the LV (70%), RV (52%) and IVS (48%) and to a lesser extent in the atria (13%) and pericardium (4%). Follow-up echocardiography in. 18'show\'ld complete postnatal regression of CR in 3, partial regression in 13 and no change in 2. Cardiac complications were encountered in 5 patients, 1 with WPW syndrome and SVT requiring anti-arrhythmic therapy, 1 with sub-aortic obstruction needing surgical intervention and 3 with occasional bouts of paroxysmal SVT. Long-term follow-up revealed tuberous sclerosis of Bourneville (TSB) as definite diagnosIs in 22 (92%), complicated by epilepsy in 16 (67%) and developmental delay in 14 (64%). Conclusions: CR generally regresses after birth and after the high risk perinatal period cardiac related problems are rare. The relatively poor neurodevelopmental outcome of the almost always associated TSB however should form a dominating aspect of the prenatal counselling of parents whose fetuses are diagnosed with this rare disease.
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Proper function of the wall of bladder requires gap junctional communication for coordinating the responses of smooth muscle (SMC) and urothelial cells exposed to urine pressure. In the rat bladder, Cx43 is expressed by SMC and urothelial cells, whereas Cx26 expression is restricted to the epithelium. We used a model of bladder outlet obstruction, in which a ligature is placed around the urethra to increase voiding pressure. Increased fluid pressure was associated with increased Cx43 and Cx26 mRNA expression and with the activation of a signaling cascade including the transcription factor c-Jun, which is a component of the AP-1 complex. The signaling pathway of the c-Jun NH2 terminal kinase (JNK) requires the presence of the scaffold protein Islet-Brain1/c-Jun amino-terminal kinase Interacting Protein-1 (IB1/JIP-1). Under stress conditions resulting from urine retention, we have found a reduced content of IB1/JIP-1 in urothelial cells, which in turn induced a drastic increase of JNK and AP-1 binding activities. The stress-induced activation of JNK was prevented by overexpressing IB1/JIP-1, using a viral gene transfer approach, a condition which also resulted in a decrease in Cx26 mRNA. The data show that: 1) mechanical stress of urothelial cells activates in vivo JNK, as a consequence of a regulated expression of IB1/JIP-1 and 2) that urothelial Cx26 may be directly regulated by the AP-1 complex.
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La sténose de l'artère rénale (SAR) est souvent associée à une maladie athéromateuse diffuse et, en conséquence, à une morbidité et une mortalité cardiovasculaires accrues. Le nombre de revascularisations de l'artère rénale a considérablement augmenté ces dernières années. Mais les succès rapportés par cette procédure, par rapport à un traitement médical seul, semblent modestes tant sur le contrôle de la pression artérielle que sur la progression de l'insuffisance rénale. La mise en évidence d'une SAR ne représente pas systématiquement une indication à une revascularisation. Plusieurs critères doivent être pris en compte, dont la localisation de la sténose, son retentissement hémodynamique, la fonction rénale, la sévérité de l'hypertension artérielle et la facilité avec laquelle le traitement antihypertenseur parvient à normaliser la pression artérielle. Atherosclerotic renal artery stenosis is often associated with diffuse atherosclerotic disease and consequently an increased cardiovascular morbidity and mortality. Despite evidence of only moderate clinical benefit in comparison with medical treatment to control the blood pressure and to prevent renal failure, renal endovascular revascularisation has become more and more popular. The decision to treat an atherosclerotic renal stenosis by revascularisation should be taken only after a close examination of the hemodynamic impact of the stenosis, the renal function, the severity of hypertension and the quality of blood pressure control achieved by the medical treatment
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Bronchiolitis obliterans (BO) following allogeneic haematopoietic stem cell transplantation (HSCT) affects peripheral airways. Detection of BO is presently delayed by the low sensitivity of spirometry. We examined the relationship between peripheral airway function and time since HSCT, and compared it with spirometry and clinical indices in 33 clinically stable allogeneic HSCT recipients. The following measurements were performed: lung function, exhaled nitric oxide, forced oscillatory respiratory system resistance and reactance, acinar (S(acin)) and conductive airways ventilation heterogeneity and lung clearance index (LCI) measured by multiple breath nitrogen washout. 22 patients underwent repeat visits from which short-term changes were examined. Median time post HSCT was 12 months. Eight patients were clinically diagnosed as having BO. In multivariate analysis, time since HSCT was predicted by S(acin) and forced expiratory volume in 1 s % predicted. 20 patients had abnormal S(acin) with normal spirometry, whereas none had airflow obstruction with normal S(acin). S(acin) and LCI were the only measures to change significantly between two visits, with both worsening. Change in S(acin) was the only parameter to correlate with change in chronic graft-versus-host disease grade. In conclusion, peripheral airways ventilation heterogeneity worsens with time after HSCT. S(acin) may be more sensitive than spirometry in detecting BO at an early stage, which needs confirmation in a prospective study.
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Roux-en-Y gastric bypass (RYGBP) is currently the most common bariatric procedure. One of its late complications is the development of internal hernia, which can lead to acute intestinal obstruction or recurrent colicky abdominal pain. The aim of this paper is to present a new, unusual, and so far not reported type of internal hernia. A common computerized database is maintained for all patients undergoing bariatric surgery in our departments. The charts of patients with the diagnosis of internal hernia were reviewed. Three patients were identified who developed acute intestinal obstruction due to an internal hernia located between the jejunojejunostomy and the end of the biliopancreatic limb, directly between two jejunal limbs with no mesentery involved. Another seven patients with intermittent colicky abdominal pain, re-explored for the suspicion of internal hernia, were found to also have an open window of the same location apart from a hernia at one of the typical hernia sites. Since this gap is systematically closed during RYGBP, no other patient has been observed with this problem. Even very small defects can lead to the development of internal hernias after RYGBP. Patients with suggestive symptoms must be explored. Closure of the jejunojejunal defect with nonabsorbable sutures prevents the development of an internal hernia between the jejunal loops at the jejunojejunostomy.
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This paper provides an explicit cofibrant resolution of the operad encoding Batalin-Vilkovisky algebras. Thus it defines the notion of homotopy Batalin-Vilkovisky algebras with the required homotopy properties. To define this resolution we extend the theory of Koszul duality to operads and properads that are defind by quadratic and linear relations. The operad encoding Batalin-Vilkovisky algebras is shown to be Koszul in this sense. This allows us to prove a Poincare-Birkhoff-Witt Theorem for such an operad and to give an explicit small quasi-free resolution for it. This particular resolution enables us to describe the deformation theory and homotopy theory of BV-algebras and of homotopy BV-algebras. We show that any topological conformal field theory carries a homotopy BV-algebra structure which lifts the BV-algebra structure on homology. The same result is proved for the singular chain complex of the double loop space of a topological space endowed with an action of the circle. We also prove the cyclic Deligne conjecture with this cofibrant resolution of the operad BV. We develop the general obstruction theory for algebras over the Koszul resolution of a properad and apply it to extend a conjecture of Lian-Zuckerman, showing that certain vertex algebras have an explicit homotopy BV-algebra structure.
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BACKGROUND AND PURPOSE: We aimed to assess the interaction between intravenous thrombolysis (IVT) and arterial occlusion on acute cervicocerebral computed tomographic angiography on the outcome of patients with acute ischemic stroke. METHODS: Patients from the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) registry with onset-to-door-time ≤4 hours, acute cervicocerebral computed tomographic angiography, a premorbid modified Rankin Scale ≤2, and a National Institute of Health Stroke Scale (NIHSS) >4 were selected. Patients with significant intracranial arterial obstruction (≥50%-99%) and undergoing acute endovascular treatment were excluded. An interaction analysis of IVT and initial arterial occlusion for favorable 3 months outcome (modified Rankin Scale <3) were performed with adjustment for potential confounders. RESULTS: Among 654 included patients, 382 (58%) showed arterial occlusion, of whom 263 (69%) received IVT. Two hundred seventy-two showed no/minimal obstruction of whom 139 (51%) received IVT. In the adjusted interaction analysis, there was a trend in favor of the arterial occlusion group (odds ratio [OR]=3.97; 95% confidence interval [CI], 0.83-18.97; P=0.08). IVT (versus no IVT) was associated with better outcome in patients with occlusion (adjusted OR for favorable outcome, 3.01; 95% CI, 1.10-8.28) but not in patients with no/minimal obstruction (OR, 0.76; 95% CI, 0.21-2.74). Conversely, patients with occlusion had a similar rate of favorable outcome as no/minimal obstruction when thrombolysed (OR, 0.5; 95% CI, 0.17-1.47) but had a less favorable outcome without thrombolysis (OR, 0.13; 95% CI, 0.04-0.44). CONCLUSIONS: In this retrospective analysis of consecutive patients with acute ischemic stroke, there was a trend for more favorable outcomes with IVT in the setting of initial arterial occlusion than in the setting of no/minimal obstruction. Before confirmation in randomized controlled studies, this information should not influence thrombolysis decisions, however.
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Anorectal malformation (ARM) can be divided in high, intermediate, and low forms according to the level of termination of the rectum in relation to the pubococcygeal and ischiatic lines. Patients with Down's syndrome have a high incidence of gastrointestinal anomalies, such as tracheoesophageal fistula, duodenal obstruction, annular pancreas, Hirschsprung's disease, and ARM. In these children, ARM is generally low with or without a fistula. The mode of inheritance of ARM and its genetic relation with Down's syndrome is not known, even if the association (ARM-Down's syndrome) seems not to be coincidental. We describe here a very rare case of monozygotic twins born with the association of ARM and Down's syndrome.
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Lymphangioleiomyomatosis is a rare pulmonary disease encountered almost exclusively in women of reproductive age. Pulmonary involvement is characterized by multiple thin-walled cysts in the lungs, recurrent pneumothorax, obstructive lung disorders, and progression to chronic respiratory failure over a mean period of 10 years. Certainty of diagnosis requires a lung biopsy, but international criteria have been proposed for a diagnosis without such a biopsy. International recommendations were recently issued for the diagnosis and treatment of lymphangioleiomyomatosis. Treatment is principally symptomatic and relies on the management of bronchial obstruction by bronchodilators; of hypoxemia by oxygen therapy; of pleural complications by pleurodesis, most often surgical; and of renal angiomyolipomas by percutaneous embolization in cases of hemorrhagic risk. Hormone treatment is not recommended. Hopes are high for mTor inhibitors (sirolimus and everolimus) and treatment trials are currently underway. Lung transplantation must be considered when chronic respiratory failure occurs in patients younger than 60 years.
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Recent data have implicated thrombospondin-1 (TSP-1) signaling in the acute neuropathological events that occur in microvascular endothelial cells (ECs) following spinal cord injury (SCI) (Benton et al., 2008b). We hypothesized that deletion of TSP-1 or its receptor CD47 would reduce these pathological events following SCI. CD47 is expressed in a variety of tissues, including vascular ECs and neutrophils. CD47 binds to TSP-1 and inhibits angiogenesis. CD47 also binds to the signal regulatory protein (SIRP)α and facilitates neutrophil diapedesis across ECs to sites of injury. After contusive SCI, TSP-1(-/-) mice did not show functional improvement compared to wildtype (WT) mice. CD47(-/-) mice, however, exhibited functional locomotor improvements and greater white matter sparing. Whereas targeted deletion of either CD47 or TSP-1 improved acute epicenter vascularity in contused mice, only CD47 deletion reduced neutrophil diapedesis and increased microvascular perfusion. An ex vivo model of the CNS microvasculature revealed that CD47(-/-)-derived microvessels (MVs) prominently exhibit adherent WT or CD47(-/-) neutrophils on the endothelial lumen, whereas WT-derived MVs do not. This implicates a defect in diapedesis mediated by the loss of CD47 expression on ECs. In vitro transmigration assays confirmed the role of SIRPα in neutrophil diapedesis through EC monolayers. We conclude that CD47 deletion modestly, but significantly, improves functional recovery from SCI via an increase in vascular patency and a reduction of SIRPα-mediated neutrophil diapedesis, rather than the abrogation of TSP-1-mediated anti-angiogenic signaling.
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BACKGROUND: : Superselective ophthalmic artery chemotherapy (SOAC) has recently been proposed as an alternative to intravenous chemoreduction for advanced intraocular retinoblastoma. Preliminary results appear promising in terms of tumor control and eye conservation, but little is known regarding ocular toxicity and visual prognosis. In this study, we report on the vascular adverse effects observed in our initial cohort of 13 patients. METHODS: : The charts of 13 consecutive patients with retinoblastoma who received a total of 30 injections (up to 3 injections of a single agent per patient at 3-week interval) of melphalan (0.35 mg/kg) in the ophthalmic artery between November 2008 and June 2010 were retrospectively reviewed. RetCam fundus photography and fluorescein angiography were performed at presentation and before each injection. Vision was assessed at the latest visit. RESULTS: : Enucleation and external beam radiotherapy could be avoided in all cases but one, with a mean follow-up of 7 months. Sectoral choroidal occlusive vasculopathy leading to chorioretinal atrophy was observed temporally in 2 eyes (15%) 3 weeks to 6 weeks after the beginning of SOAC and retinal arteriolar emboli in 1 eye 2 weeks after injection. There was no stroke or other clinically significant systemic side effects except a perioperative transient spasm of the internal carotid artery in one patient. Vision ranged between 20/1600 and 20/32 depending on the status of the macula. CONCLUSION: : Superselective ophthalmic artery chemotherapy was effective in all patients with no stroke or other systemic vascular complications. Unlike intravenous chemoreduction, SOAC is associated with potentially sight-threatening adverse effects, such as severe chorioretinal atrophy secondary to subacute choroidal occlusive vasculopathy or central retinal artery embolism, not to mention the risk of ophthalmic artery obstruction, which was not observed in this series. Further analysis of the risks and benefits of SOAC will define its role within the therapeutic arsenal. Meanwhile, we suggest that SOAC should be given in one eye only and restricted to advanced cases of retinoblastoma, as an alternative to enucleation and/or external beam radiotherapy.
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Changes in vascular structure that accompany hypertension may contribute to hypertensive end-organ damage. Both the macrovascular and microvascular levels should be considered, as interactions between them are believed to be critically important. Regarding the macrocirculation, the article first reviews basic concepts of vascular biomechanics, such as arterial compliance, arterial distensibility, and stress-strain relationships of arterial wall material, and then reviews how hypertension affects the properties of conduit arteries, particularly examining evidence that it accelerates the progressive stiffening that normally occurs with advancing age. High arterial stiffness may increase central systolic and pulse pressure by two different mechanisms: 1) Abnormally high pulse wave velocity may cause pressure waves reflected in the periphery to reach the central aorta in systole, thus augmenting systolic pressure; 2) In the elderly, the interaction of the forward pressure wave with high arterial stiffness is mostly responsible for abnormally high pulse pressure. At the microvascular level, hypertensive disease is characterized by inward eutrophic or hypertrophic arteriolar remodeling and capillary rarefaction. These abnormalities may depend in part on the abnormal transmission of highly pulsatile blood pressure into microvascular networks, especially in highly perfused organs with low vascular resistance, such as the kidney, heart, and brain, where it contributes to hypertensive end-organ damage.
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Deeply incised river networks are generally regarded as robust features that are not easily modified by erosion or tectonics. Although the reorganization of deeply incised drainage systems has been documented, the corresponding importance with regard to the overall landscape evolution of mountain ranges and the factors that permit such reorganizations are poorly understood. To address this problem, we have explored the rapid drainage reorganization that affected the Cahabon River in Guatemala during the Quaternary. Sediment-provenance analysis, field mapping, and electrical resistivity tomography (ERT) imaging are used to reconstruct the geometry of the valley before the river was captured. Dating of the abandoned valley sediments by the Be-10-Al-26 burial method and geomagnetic polarity analysis allow us to determine the age of the capture events and then to quantify several processes, such as the rate of tectonic deformation of the paleovalley, the rate of propagation of post-capture drainage reversal, and the rate at which canyons that formed at the capture sites have propagated along the paleovalley. Transtensional faulting started 1 to 3 million years ago, produced ground tilting and ground faulting along the Cahabon River, and thus generated differential uplift rate of 0.3 +/- 0.1 up to 0.7 +/- 0.4 mm . y(-1) along the river's course. The river responded to faulting by incising the areas of relative uplift and depositing a few tens of meters of sediment above the areas of relative subsidence. Then, the river experienced two captures and one avulsion between 700 ky and 100 ky. The captures breached high-standing ridges that separate the Cahabon River from its captors. Captures occurred at specific points where ridges are made permeable by fault damage zones and/or soluble rocks. Groundwater flow from the Cahabon River down to its captors likely increased the erosive power of the captors thus promoting focused erosion of the ridges. Valley-fill formation and capture occurred in close temporal succession, suggesting a genetic link between the two. We suggest that the aquifers accumulated within the valley-fills, increased the head along the subterraneous system connecting the Cahabon River to its captors, and promoted their development. Upon capture, the breached valley experienced widespread drainage reversal toward the capture sites. We attribute the generalized reversal to combined effects of groundwater sapping in the valley-fill, axial drainage obstruction by lateral fans, and tectonic tilting. Drainage reversal increased the size of the captured areas by a factor of 4 to 6. At the capture sites, 500 m deep canyons have been incised into the bedrock and are propagating upstream at a rate of 3 to 11 mm . y(-1) deepening at a rate of 0.7 to 1 5 mm . y(-1). At this rate, 1 to 2 million years will be necessary for headward erosion to completely erase the topographic expression of the paleovalley. It is concluded that the rapid reorganization of this drainage system was made possible by the way the river adjusted to the new tectonic strain field, which involved transient sedimentation along the river's course. If the river had escaped its early reorganization and had been given the time necessary to reach a new dynamic equilibrium, then the transient conditions that promoted capture would have vanished and its vulnerability to capture would have been strongly reduced.
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Neutrophil NETosis is an important element of host defense as it catapults chromatin out of the cell to trap bacteria, which then are killed, e.g., by the chromatin's histone component. Also, during sterile inflammation TNF-alpha and other mediators trigger NETosis, which elicits cytotoxic effects on host cells. The same mechanism should apply to other forms of regulated necrosis including pyroptosis, necroptosis, ferroptosis, and cyclophilin D-mediated regulated necrosis. Beyond these toxic effects, extracellular histones also trigger thrombus formation and innate immunity by activating Toll-like receptors and the NLRP3 inflammasome. Thereby, extracellular histones contribute to the microvascular complications of sepsis, major trauma, small vessel vasculitis as well as acute liver, kidney, brain, and lung injury. Finally, histones prevent the degradation of extracellular DNA, which promotes autoimmunization, anti-nuclear antibody formation, and autoimmunity in susceptible individuals. Here, we review the current evidence on the pathogenic role of extracellular histones in disease and discuss how to target extracellular histones to improve disease outcomes.