RESUMO
INTRODUCTION: Few studies described strategies to improve the use of diagnostic tests in intensive care units (ICU). No study assessed whether their impact was sustained or not. In this study, we assessed whether a multi-faceted intervention for more appropriate use of laboratory testing can decrease the number of tests, is sustainable, is not associated with additional morbidity and represents a potential cost saving. MATERIAL AND METHODS: An open-label prospective cohort study in two separated units of the same medical intensive care unit (ICU) including respectively 3315 and 2392 consecutive patients. After the observation period (2010), a reduction in ICU A of unnecessary diagnostics tests as part of a program including senior supervisory of juniors' orders, encouragements for orders containment at each everyday round discussions (period 2; 2011). Period 3 (2012) consisted in the prolongation of the protocol as a routine care without supervision; Period 4 (2013) was a new period of observation without intervention. No modification was implemented in ICU B in periods 2-4. RESULTS: After the intervention, a decrease in the overall number of tests per ICU-patient-days (37.3±5.5 (baseline) to 15.2±3.2 (- 59%); p<0.0001) was observed. The total cost of the tests decreased from 239±41 to 104±28 euros per ICU-patient days; p<0.0001. The effect on laboratory test orders was sustainable in period 3 (-49%) and 4 (-30%). No significant secondary effect of the intervention was observed in period 2. In ICU B, there was no significant change in the overall laboratory test orders in between the periods. CONCLUSIONS: Laboratory test containment is effective, likely safe and sustainable provided that an educational program is repeatedly promoted, that it makes sense for the whole team, that senior and junior physicians are both committed in the program, and that encouragements for laboratory orders containment at each everyday round discussions.
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Cuidados Críticos/métodos , Testes Diagnósticos de Rotina , Corpo Clínico Hospitalar/educação , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Estudos Prospectivos , Procedimentos Desnecessários/tendênciasRESUMO
See Duering and Schmidt (doi:10.1093/awx135) for a scientific commentary on this article.Thalamic alterations have been observed in infarcts initially sparing the thalamus but interrupting thalamo-cortical or cortico-thalamic projections. We aimed at extending this knowledge by demonstrating with in vivo imaging sensitive to iron accumulation, one marker of neurodegeneration, that (i) secondary thalamic alterations are focally located in specific thalamic nuclei depending on the initial infarct location; and (ii) such secondary alterations can contribute independently to the long-term outcome. To tackle this issue, 172 patients with an infarct initially sparing the thalamus were prospectively evaluated clinically and with magnetic resonance imaging to quantify iron through R2* map at 24-72 h and at 1-year follow-up. An asymmetry index was used to compare R2* within the thalamus ipsilateral versus contralateral to infarct and we focused on the 95th percentile of R2* as a metric of high iron content. Spatial distribution within the thalamus was analysed on an average R2* map from the entire cohort. The asymmetry index of the 95th percentile within individual nuclei (medio-dorsal, pulvinar, lateral group) were compared according to the initial infarct location in simple and multiple regression analyses and using voxel-based lesion-symptom mapping. Associations between the asymmetry index of the 95th percentile and functional, cognitive and emotional outcome were calculated in multiple regression models. We showed that R2* was not modified at 24-72 h but showed heterogeneous increase at 1 year mainly within the medio-dorsal and pulvinar nuclei. The asymmetry index of the 95th percentile within the medio-dorsal nucleus was significantly associated with infarcts involving anterior areas (frontal P = 0.05, temporal P = 0.02, lenticular P = 0.01) while the asymmetry index of the 95th percentile within the pulvinar nucleus was significantly associated with infarcts involving posterior areas (parietal P = 0.046, temporal P < 0.001) independently of age, gender and infarct volume, which was confirmed by voxel-based lesion-symptom mapping. The asymmetry index of the 95th percentile within the entire thalamus at 1 year was independently associated with poor functional outcome (P = 0.04), poor cognitive outcome (P = 0.03), post-stroke anxiety (P = 0.04) and post-stroke depression (P = 0.02). We have therefore identified that iron accumulates within the thalamus ipsilateral to infarct after a delay with a focal distribution that is strongly linked to the initial infarct location (in relation with the pattern of connectivity between thalamic nuclei and cortical areas or deep nuclei), which independently contributes to functional, cognitive and emotional outcome.
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Infarto Cerebral/patologia , Ferro/metabolismo , Núcleos Talâmicos/metabolismo , Núcleos Talâmicos/patologia , Adulto , Idoso de 80 Anos ou mais , Infarto Cerebral/complicações , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Fatores de TempoRESUMO
BACKGROUND: Non-muscle invasive bladder cancer (NMIBC) is usually treated with local therapy including transurethral resection of the bladder tumor and intravesical therapy depending on the stage of the tumor. NMIBC is a rarely a metastatic diseases with lymph node invasion in less of 10%. In the other hand meningeal carcinomatosis is a rare location for metastases with extremely poor outcomes. We described a case report of a patient presenting a metastatic disease to bones and meninges, several years after the treatment of NMIBC, which had been in complete response (CR) for 4 years after chemotherapy treatment. CASE PRESENTATION: A 63-years old men was treated by TURBT in 2008 for a high grade NMIBC, pT1b. Three years later he presented an acute binocular diplopy with right trochlear nerve paralysis, and labial hypoesthesia. Brain scan and MRI were performed finding a clivus infiltration and a pachymeningitis. A vertebral biopsy was performed finding an invasive carcinoma, CK7+/CK20+, TTF1-, PSA-, Thyroglobulin- and GATA3+. The metastatic event was in relation to the high grade NMIBC treated 3 years previously. Palliative chemotherapy was started with cisplatin gemcitabine. After 6 cycles and to date, 4 years later, the patient is therefore considered in complete response. CONCLUSION: Metastasis in non-muscle invasive urothelial carcinoma is rare. Meningeal carcinomatosis outcome is poor, usually appearing in widely metastatic and progressive cancers but also because most systemic agents fail to pass the blood-brain barrier and penetrate into the cerebrospinal fluid. We described an unexpected response with complete response after chemotherapy for meningeal carcinomatosis of non muscle invasive urothelial carcinoma.
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Carcinomatose Meníngea/tratamento farmacológico , Carcinomatose Meníngea/secundário , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Antineoplásicos/uso terapêutico , Cisplatino/uso terapêutico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Humanos , Masculino , Carcinomatose Meníngea/patologia , Pessoa de Meia-Idade , Resultado do Tratamento , GencitabinaRESUMO
BACKGROUND AND OBJECTIVES: The Penumbra Coil 400 (PC400) is designed to improve endovascular filling for intracranial aneurysms. The aim of this retrospective, single-operator study was to compare the use of the PC400 with conventional 0.010inch coils in procedure time, X-ray exposure and packing density. METHODS: We collected data from 31patients with 6 to 10mm diameter aneurysms embolized using the PC400, from May 2012 to November 2013. This group was compared with a control group of 27patients treated with conventional 0.010inch coils by the same operator. In both groups, clinical events, number of coils used, duration and cost of procedure, time of fluoroscopy and packing density were studied. RESULTS: No serious adverse events were found in either group. Asymptomatic prolapse of coil loop into the parent artery were noted in two patients. Number of coils used was 4.45/6.35 in PC400 and control groups, respectively. Duration of procedure was 29.8/49.2minutes respectively (P-value=0.0002), and time of fluoroscopy was 28/41minutes (P-value=0.0109). Total radiation was 6098/6876cGy.cm(2) respectively. Comparison of packing densities after the first coil showed respectively 22.7%/10.6%, and after the final imaging, 53%/28.5% (P-values<0.0001). Complete or near complete occlusion on follow-up at 3months was 100% for PC400 versus 92% in the control group. Using 0.010inch coils may result in a 56% increase in treatment cost. CONCLUSION: PC400 coils save procedural time and time of fluoroscopy, are cost saving and allow dramatic improvement of packing density on final imaging.
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Embolização Terapêutica/instrumentação , Aneurisma Intracraniano/terapia , Procedimentos Endovasculares , Feminino , Humanos , Aneurisma Intracraniano/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoAssuntos
Vazamento de Líquido Cefalorraquidiano/diagnóstico , Vazamento de Líquido Cefalorraquidiano/etiologia , Cefaleia/etiologia , Sacro/lesões , Fraturas da Coluna Vertebral/complicações , Cistos de Tarlov/complicações , Adulto , Vazamento de Líquido Cefalorraquidiano/terapia , Cistos , Diagnóstico Diferencial , Feminino , Cefaleia/diagnóstico , Cefaleia/terapia , Humanos , Ruptura , Doenças da Medula Espinal , Fraturas da Coluna Vertebral/diagnóstico , Cistos de Tarlov/diagnóstico , Cistos de Tarlov/terapia , Resultado do TratamentoAssuntos
Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Leucoencefalopatias/induzido quimicamente , Leucoencefalopatias/patologia , Vidarabina/análogos & derivados , Antineoplásicos/efeitos adversos , Encéfalo/efeitos dos fármacos , Diagnóstico Diferencial , Seguimentos , Humanos , Leucemia/complicações , Leucemia/tratamento farmacológico , Leucemia/patologia , Leucoencefalopatias/prevenção & controle , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Vidarabina/efeitos adversosRESUMO
PURPOSE: To investigate imaging characteristics of post-embolised meningioma and to determine if SW imaging can delineate tumour ischaemia. MATERIALS AND METHODS: Sixteen patients were studied before and after preoperative embolisation therapy (8 histopathologically determined with ischaemia, 8 with non-ischaemia). In each patient, a slice-wise ROI for the entire tumour was established, and histogram variables (mean, SD, minimum, maximum, histogram width, mode, and peak height) of SW, ADC, CBV, CBF, MTT, and TTP maps were compared between ischaemic and non-ischaemic groups. Changes in SW histogram were correlated with histopathological characteristics. RESULTS: Signal intensity on the SW map tended to decrease in the ischaemic group and partially increased in the non-ischaemic group. A similar trend was observed on the ADC map. The PW histogram showed an MTT increase in ischaemic group; however, CBV did not show significant changes between ischaemic and non-ischaemic groups. Microhaemorrhage was slightly correlated with Δpeak height in the SW histogram. CONCLUSION: Post-embolisation changes of intrinsic T2-weighted MR contrasts on SW map are most likely associated with alterations in deoxyhaemoglobin levels and arterial blood flow.
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Imagem de Difusão por Ressonância Magnética/métodos , Embolização Terapêutica/métodos , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/terapia , Meningioma/patologia , Meningioma/terapia , Adulto , Idoso , Biópsia por Agulha , Mapeamento Encefálico/métodos , Terapia Combinada , Meios de Contraste , Embolização Terapêutica/efeitos adversos , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Humanos , Interpretação de Imagem Assistida por Computador , Imuno-Histoquímica , Masculino , Neoplasias Meníngeas/diagnóstico , Meningioma/diagnóstico , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Procedimentos Neurocirúrgicos/métodos , Distribuição Normal , Cuidados Pré-Operatórios/métodos , Fatores de Risco , Estudos de Amostragem , Resultado do TratamentoRESUMO
PURPOSE: To compare magnetic resonance (MR) imaging features of multiple sclerosis (MS) lesions after the administration of a gadolinium-based contrast agent and ultrasmall superparamagnetic iron oxide (USPIO) particles among the clinical phenotypes of MS and over time. MATERIALS AND METHODS: This study was approved by the local ethics committee, and written informed consent was obtained from all patients. Twenty-four patients with MS (10 with relapsing and 14 with progressive forms) underwent clinical and gadolinium- and USPIO-enhanced MR examinations at baseline and 6-month follow-up. The number of lesions that enhanced with gadolinium alone, USPIO alone, or both was compared with the Pearson χ2 or Fisher exact test, and lesion sizes were compared with the Wilcoxon Mann-Whitney U test. At 6-month follow-up, the lesion signal intensity on precontrast T1-weighted images and the enhancement after repeat injection of the contrast agent were compared with the baseline postcontrast imaging features by using the McNemar test. RESULTS: Fifty-six lesions were considered active owing to contrast enhancement at baseline; 37 lesions (66%) in 10 patients enhanced with gadolinium. The use of USPIO helped detect 19 additional lesions (34%), and two additional patients were classified as having active disease. Thus, the use of both agents enabled detection of 51% (19 of 37 lesions) more lesions than with gadolinium alone. Enhanced lesions were more frequently observed in the relapsing compared with the progressive forms of MS (P<.0001). USPIO enhancement, in the form of ringlike patterns, could also be observed on T1-weighted images in patients with progressive MS, enabling the detection of five lesions in addition to the five detected with gadolinium in this phenotype. Lesions that enhanced with both contrast agents at baseline were larger (mean size, 6.5 mm±3.8; P=.001) and were more likely to persistently enhance at 6-month follow-up (seven of 27 lesions, P<.0001) compared with those that enhanced only with gadolinium (mean size, 4.9 mm±2.2; one of nine lesions) or USPIO (mean size, 3.5 mm±1.5; 0 of 17 lesions). CONCLUSION: The combination of gadolinium and USPIO in patients with MS can help identify additional active lesions compared with the current standard, the gadolinium-only approach, even in progressive forms of MS. Lesions that enhance with both agents may exhibit a more aggressive evolution than those that enhance with only one contrast agent.
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Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/patologia , Adulto , Distribuição de Qui-Quadrado , Meios de Contraste , Dextranos , Avaliação da Deficiência , Feminino , Humanos , Estudos Longitudinais , Nanopartículas de Magnetita , Masculino , Meglumina , Pessoa de Meia-Idade , Compostos Organometálicos , Fenótipo , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estatísticas não ParamétricasRESUMO
OBJECTIVES: We compared the safety of different devices by screening for subclinical intracranial embolic events after pulmonary vein isolation with either conventional irrigated radiofrequency (RF) or cryoballoon or multielectrode phased RF pulmonary vein ablation catheter (PVAC). BACKGROUND: New devices specifically designed to facilitate pulmonary vein isolation procedures have recently been introduced. METHODS: This prospective, observational, multicenter study included patients with symptomatic atrial fibrillation referred for pulmonary vein isolation. Ablation was performed using 1 of the 3 catheters. Strict periprocedural anticoagulation, with intravenous heparin during ablation to achieve an activated clotting time >300 s, was ensured in all patients. Cerebral magnetic resonance imaging was performed before and after ablation. RESULTS: Seventy-four patients were included in the study: 27 in the irrigated RF group, 23 in the cryoballoon group, and 24 in the PVAC group. Total procedure times were 198 ± 50 min, 174 ± 35 min, and 124 ± 32 min, respectively (p < 0.001 for PVAC vs. irrigated RF and cryoballoon). Findings on neurological examination were normal in all patients before and after ablation. Post-procedure magnetic resonance imaging detected a single new embolic lesion in 2 of 27 patients in the irrigated RF group (7.4%) and in 1 of 23 in the cryoballoon group (4.3%). However, in the PVAC group 9 of 24 patients (37.5%) demonstrated 2.7 ± 1.3 new lesions each (p = 0.003 for the presence of new embolic events among the 3 groups). CONCLUSIONS: The PVAC is associated with a significantly higher incidence of subclinical intracranial embolic events. Further study of the causes and significance of these emboli is required to determine the safety of the PVAC.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Embolia Intracraniana/etiologia , Veias Pulmonares/cirurgia , Anticoagulantes/administração & dosagem , Ablação por Cateter/instrumentação , Ablação por Cateter/métodos , Criocirurgia/efeitos adversos , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Embolia Intracraniana/diagnóstico , Embolia Intracraniana/patologia , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Irrigação TerapêuticaRESUMO
Because macrophages play a key role on host defense, visualization of the migration of these cells is of high relevance for both diagnostic purposes and the evaluation of therapeutic interventions. The present article addresses the use of iron oxide and gadolinium-based particles for the noninvasive in vivo detection of macrophage infiltration into inflamed areas by magnetic resonance imaging (MRI). A general introduction on the functions and general characteristics of macrophages is followed by a discussion of some of the agents and acquisition schemes currently used to track the cells in vivo. Attention is then devoted to preclinical and clinical applications in the following disease areas: atherosclerosis and myocardial infarction, stroke, multiple sclerosis, rheumatoid arthritis, and kidney transplantation.
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Meios de Contraste/química , Aumento da Imagem/métodos , Inflamação/patologia , Ativação de Macrófagos , Macrófagos/patologia , Imageamento por Ressonância Magnética/métodos , Nanopartículas/química , Animais , HumanosRESUMO
Vanishing white matter (VWM) disease, also known as childhood ataxia with central nervous system hypomyelination (CACH) syndrome, is an autosomal recessive transmitted leukodystrophy. Classically characterised by early childhood onset, adult onset formed with slower progression have been recently recognized. The course of neurological impairment is usually progressive with possible occasional episodes of acute deterioration following febrile illnesses or head trauma. Neurological features are dominated by cerebellar ataxia and spasticity with relatively preserved mental abilities. Brain MRI shows diffuse abnormal signal of the cerebral white matter and cystic degeneration. Mutations in one of the genes coding for the five subunits of the translation factor eukaryotic initiation factor 2B (eIF2B) have been identified. We report here on two sisters affected by adult onset VWM with variable phenotypic expression. The proband is remarkable by the very late age of the disease onset (age of 42). A homozygous p.Arg113His mutation in the eIF2Bvarepsilon gene was identified. This mutation had been recurrently associated with adult onset VWM establishing phenotype-genotype correlations. We will show an important intra-familial phenotypic variability and discuss it in the light of recent molecular progresses. External precipitating factors are contributing for some of the differences observed.
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Encefalopatias/patologia , Fator de Iniciação 2B em Eucariotos/genética , Mutação , Adulto , Ataxia/genética , Ataxia/patologia , Encefalopatias/genética , Saúde da Família , Feminino , Heterogeneidade Genética , Humanos , Imageamento por Ressonância Magnética , FenótipoRESUMO
Applications of imaging techniques to visualize stem cells for monitoring, control and treatment of biological systems, in particular the brain, is at the forefront of investigations. These approaches involve the identification of stem and precursor cells that may be of various origins, but are related to specific clinical conditions, and the choice of the appropriate markers to achieve the required imaging while minimizing the side effects. This article will review examples of the contrast agent design for rational approaches in stem cell imaging. Potential pitfalls or side effects associated with contrast agents, in particular iron oxide nanoparticles, for cell labelling are also discussed.
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Movimento Celular/fisiologia , Imageamento por Ressonância Magnética/métodos , Células-Tronco/fisiologia , Animais , Diferenciação Celular/fisiologia , Meios de Contraste/metabolismo , Humanos , Transplante de Células-Tronco/métodosRESUMO
Macrophage tracking by magnetic resonance imaging (MRI) with iron oxide nanoparticles has been developed during the last decade for numerous diseases of the CNS. Experimental studies on animal models were confirmed by first clinical applications of MRI technology of brain macrophages for multiple sclerosis, ischemic stroke lesions, and tumors. As activated macrophages act in concert with other immune competent cells, this innovative MRI approach provides new functional data on the immune reaction in these CNS diseases. The MRI detection of brain macrophages defines precise spatial and temporal patterns of macrophage involvement that helps to characterize individual neurological disorders. This approach is being explored as an in vivo marker for the clinical diagnosis of cerebral lesion activity, in experimental models for the prognosis of disease development, and to determine the efficacy of immunomodulatory treatments under clinical evaluation. Comparative brain imaging follow-up studies of blood-brain barrier leakage by MRI with gadolinium-chelates, microglia activation by positron emission tomography with radiotracer ligand PK11195 and MRI detection of macrophage infiltration provide more precise information about the pathophysiological cascade of inflammatory events in cerebral diseases. Such multimodal characterization of the inflammatory events should help in the monitoring of patients, in defining precise time intervals for therapeutic interventions, and in developing and evaluating new therapeutic strategies.
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Encefalopatias/imunologia , Encefalopatias/patologia , Encéfalo/imunologia , Encéfalo/patologia , Macrófagos , Animais , Compostos Férricos , Humanos , Imageamento por Ressonância Magnética , Nanopartículas MetálicasRESUMO
STUDY DESIGN: Prospective randomized study of patients undergoing lumbar arthrodesis. OBJECTIVES: To quantify MRI changes of the erector spinae following lumbar surgery through a posterior approach and the possible protection of these muscles during surgery by the use of cholinergic blockade. SUMMARY OF BACKGROUND DATA: It has been shown that lumbar spine surgery through a posterior approach can induce iatrogenic lesions in the erector spinae. We have shown in a previous study that histologic changes on muscular biopsy performed in the multifidus at the end of the surgical procedure were not modified by the use of cholinergic blockade during surgery. METHODS: Twenty patients scheduled to undergo pedicle-screw enhanced L4-L5 arthrodesis were enrolled in this study. Ten patients received curare during anesthesia and 10 patients did not. MRI was obtained the day before the operation and at 6 months of follow-up on the same MR scanner. T1-weighted images were obtained in the axial plane. The 2 slices immediately proximal and distal to the pedicle screw construct on the postoperative MRI were selected. The corresponding slices were selected on the preoperative MRI. Each erector spinae on the 4 slices was surrounded using a mouse-guided tool. The contractile component of the cross-sectional area (CCSA) was calculated from the number of pixels surrounded and the signal intensity of each pixel. RESULTS: There was only slight changes in the erector spinae CCSA proximal to a posterior lumbar arthrodesis. Erector spinae CCSA decreased by 27% distal to the arthrodesis. Curare showed no efficacy in preventing muscle damage. CONCLUSIONS: Erector spinae muscle alterations mainly occur distal to posterior lumbar surgical procedures.
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Lesões nas Costas/prevenção & controle , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética , Músculo Esquelético/efeitos dos fármacos , Fármacos Neuromusculares não Despolarizantes/administração & dosagem , Fusão Vertebral/efeitos adversos , Adulto , Lesões nas Costas/etiologia , Lesões nas Costas/patologia , Curare/administração & dosagem , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/lesões , Músculo Esquelético/patologia , Estudos Prospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Large inflammatory infiltrates of T cells, macrophages and B cells in the central nervous system (CNS) contribute to the pathogenesis of multiple sclerosis (MS). The passage of T cells through the blood-brain barrier can be suppressed with antibodies directed against alpha-4 integrins (VLA-4) that mediate T-cell adherence. This treatment, in phase III of clinical trial evaluation, reduces lesion development in MS patients. In the ongoing inflammatory disease process the consequences of T-cell inhibitory anti-VLA-4 antibodies on inflammatory compounds are still poorly investigated. We show that anti-VLA-4 antibody treatment during the late preclinical phase of the acute experimental autoimmune encephalomyelitis (EAE) MS rat model interrupts T-cell egress out of the vascular compartment and suppresses clinical disease and histological alterations but macrophage recruitment in the CNS is not fully compromised. Among the treated EAE animals not developing disease, none presented foci of T-cell infiltration in CNS. However, in 75% of the treated EAE rats monocyte ingress in CNS was observed in vivo by magnetic resonance imaging with the ultrasmall superparamagnetic iron oxide contrast agent. Our data shed new light on the role of remaining macrophage brain infiltration in an induced but interrupted T-cell-mediated EAE disease process.
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Anticorpos Monoclonais/farmacologia , Encefalomielite Autoimune Experimental , Integrina alfa4beta1/imunologia , Macrófagos/imunologia , Linfócitos T/imunologia , Doença Aguda , Animais , Anticorpos Monoclonais Humanizados , Biomarcadores , Meios de Contraste , Cisteína , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Epitopos/imunologia , Feminino , Compostos Férricos , Macrófagos/patologia , Imageamento por Ressonância Magnética , Monócitos/imunologia , Monócitos/patologia , Natalizumab , Ratos , Ratos Endogâmicos Lew , Soroalbumina Bovina , Linfócitos T/patologiaRESUMO
The long blood circulating time and the progressive macrophage uptake in inflammatory tissues of ultrasmall superparamagnetic iron oxide (USPIO) particles are 2 properties of major importance for magnetic resonance imaging (MRI) pathologic tissue characterization. This article reviews the proof of principle of applications such as imaging of carotid atherosclerotic plaque, stroke, brain tumor characterization, or multiple sclerosis. In the human carotid artery, USPIO accumulation in activated macrophages induced a focal drop in signal intensity compared with preinfusion MRI. The USPIO signal alterations observed in ischemic areas of stroke patients is probably related to the visualization of inflammatory macrophage recruitment into human brain infarction since animal experiments in such models demonstrated the internalization of USPIO into the macrophages localized in these areas. In brain tumors, USPIO particles which do not pass the ruptured blood-brain barrier at early times postinjection can be used to assess tumoral microvascular heterogeneity. Twenty-four hours after injection, when the cellular phase of USPIO takes place, the USPIO tumoral contrast enhancement was higher in high-grade than in low-grade tumors. Several experimental studies and a pilot multiple sclerosis clinical trial in 10 patients have shown that USPIO contrast agents can reveal the presence of inflammatory multiple sclerosis lesions. The enhancement with USPIO does not completely overlap with the gadolinium chelate enhancement. While the proof of concept that USPIO can visualize macrophage infiltrations has been confirmed in animals and patients in several applications (carotid atherosclerotic lesions, stroke, brain tumors and multiple sclerosis), larger prospective clinical studies are needed to demonstrate the clinical benefit of using USPIO as an MRI in vivo surrogate marker for brain inflammatory diseases.
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Arteriosclerose/diagnóstico , Artérias Carótidas/patologia , Doenças das Artérias Carótidas/diagnóstico , Sistema Nervoso Central/fisiopatologia , Compostos Férricos/farmacocinética , Ferro/farmacocinética , Macrófagos , Imageamento por Ressonância Magnética , Óxidos/farmacocinética , Arteriosclerose/metabolismo , Doenças das Artérias Carótidas/metabolismo , Meios de Contraste , Dextranos , Óxido Ferroso-Férrico , Humanos , Aumento da Imagem , Nanopartículas de MagnetitaAssuntos
Encefalomielite Autoimune Experimental/imunologia , Macrófagos/fisiologia , Animais , Meios de Contraste , Dextranos , Encefalomielite Autoimune Experimental/diagnóstico , Feminino , Óxido Ferroso-Férrico , Ferro , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Óxidos , Ratos , Ratos Endogâmicos Lew , Índice de Gravidade de Doença , Fatores de TempoRESUMO
We present a method for labeling bone marrow haematopoietic progenitor cells with iron particles. Labeling was assessed by magnetic resonance imaging and electron microscopy. Labeling with iron particles could allow the following by imaging techniques of haematopoietic cells in physiologic and pathologic conditions such as the engraftment of haematopoietic progenitor cells or the migration of myelomonocytic cells in inflammatory diseases.