RESUMEN
The determination of age-dated metal sediment accumulation rates in a representative South American bay is able to portray the dimension of human impacts during the colonial occupation and industrial periods. Many studies have assessed metal distribution and chronology at Guanabara Bay, in Brazil. However, understanding natural variabilities associated to paleoclimatic changes and comparing these natural variabilities to anthropogenic processes are not well established to date. Accurate geochronological control integrating ages determined by 210Pb and 14C chronologies through an exponential spline fit model allowed for a precise definition of changes associated to the holocene marine transgression, as well as the colonial period, leading to intense land use changes, and the industrial period. The reference values of the system were defined based on their concentrations and the accumulation rates of ecotoxicologically important metals. Al, Ba, Fe, Cd, Cu, Cr, Li, Ni, Mn, Pb, Si, Ti, V, and Zn distributions were determined in a Guanabara Bay core (BG-28) by the EPA 3051 method. Elemental distribution profile assessment allowed for the identification of variabilities associated to weathering processes, predominantly of lithogenic origin, mainly for Al, Ba, Fe, Li, Si, and V. Weathering processes occurred simultaneously to land use changes in the drainage basin since the colonial period, at 400 cal yr BP, and during the industrial period, mainly after the 1960s, denoted by Cd, Cr, Cu, Mn, Pb and Zn increases. The highest average metal enrichment values metals associated to industrial processes reached 5.95, with 119.1-fold higher accumulation rates than the background accumulation values observed between 4200 and 500 cal yr BP.
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Metales Pesados , Contaminantes Químicos del Agua , Bahías , Brasil , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
The Hindustan citrus mite, Schizotetranychus hindustanicus Hirst (Acari: Tetranychidae), is a quarantine pest present in the state of Roraima, Brazil. This mite, which was described in India in 1924, was reported in 2002 in Venezuela and spread to Roraima, where it was reported in 2008, and to Colombia, where it was reported in 2010. Its possible spread to other regions of Brazil is a threat to Brazilian citriculture. This study reports the current distribution of S. hindustanicus and potential predators of this pest and other mites associated with citrus in Roraima. A survey was conducted in August and September 2015 in the 15 municipalities of the state. In each municipality, orchards and citrus plants in backyards and public areas along highways and in urban areas were sampled. Samples of leaves and fruits were collected to identify the mite and its natural enemies. Schizotetranychus hindustanicus was found in all 15 municipalities in the state of Roraima. In total, 308 associated mites were found, with S. hindustanicus being the most abundant phytophagous mite, followed by Brevipalpus yothersi Baker. Amblyseius aerialis (Muma) was the most abundant predator, followed by Iphiseiodes zuluagai Denmark and Muma and Euseius concordis (Chant). The broad dispersal of S. hindustanicus in Roraima increases the risks of this pest reaching the main citrus-producing regions in Brazil.
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Distribución Animal , Tetranychidae , Animales , BrasilRESUMEN
The aim of this study was to compare the volumetric changes and the new bone microarchitecture in human maxillary sinuses augmented with bioactive glass (Biogran) alone, bioactive glass combined with autogenous bone graft (1:1), or autogenous bone graft alone. Twelve maxillary sinuses were grafted with bioactive glass (group 1), nine with bioactive glass mixed with autogenous bone graft 1:1 (group 2), and 12 with autogenous bone graft (group 3). Patients underwent cone beam computed tomography 15days after the procedure to determine the initial volume of the graft (T1) and again 6 months later (T2). Biopsies were obtained at the time of dental implant placement and were subjected to micro-computed tomography. The volumetric change was 44.2% in group 1, 37.9% in group 2, and 45.7% in group 3 (P>0.05). The trabecular microarchitecture results showed that the materials used in groups 1 and 2 were good bone substitutes. However, the addition of 50% bioactive glass to autogenous bone graft improved the microarchitecture of the graft. Furthermore, the results for volumetric changes indicated that bioactive glass, its association with autogenous bone graft in a 1:1 ratio, and autogenous bone graft alone have similar resorption.
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Materiales Biocompatibles/uso terapéutico , Trasplante Óseo/métodos , Implantación Dental Endoósea/métodos , Implantes Dentales , Vidrio , Elevación del Piso del Seno Maxilar/métodos , Adulto , Biopsia , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Estudios Prospectivos , Resultado del Tratamiento , Microtomografía por Rayos XRESUMEN
The quantification of ten microorganisms at the root ends and in the surrounding periradicular lesions was performed. Thirty 3 mm samples root ends and 30 samples of the surrounding chronic periapical infection were collected during apical microsurgery. Samples were triturated, and the bacterial DNA was obtained. The bacterial quantification was performed by using the SYBR Green system. At least one microorganism was detected in all patients. In both the root end and periapical samples, Fusobacterium nucleatum (71.6%), Dialister pneumosintes (58.3%) and Tannerella forsythia (48.3%) were the most prevalent species. Dialister pneumosintes showed statistically significant values in the root end, and F. nucleatum was also significant in the apical periodontitis samples. A statistically significant association between T. forsythia and Porphyromonas gingivalis in the root ends was observed. Bacterial associations from 2 to 7 species were observed in most samples. Extra-radicular and/or intra-radicular infections were present in all teeth with failed endodontic treatment, and showed polymicrobial infection in most cases, with a predominance of F. nucleatum, D. pneumosintes and T. forsythia. When present, Enterococcus faecalis was never found to be the most prevalent species. The presence of a microbial diversity in post-treatment apical periodontitis confirms the polymicrobial and synergistic characteristic of this process. Our results show that the bacterial array associated with the 3 mm root ends and periradicular lesions in post-treatment apical periodontitis are complex and with a high inter-individual variability. These results might be useful to delineate treatment strategies for microbial elimination in apical periodontitis. Further studies are necessary to elucidate the role of these microorganisms in endodontic treatment failures.
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Cavidad Pulpar/microbiología , Fusobacterium nucleatum/aislamiento & purificación , Pulpitis/microbiología , Tannerella forsythia/aislamiento & purificación , Veillonellaceae/aislamiento & purificación , Adolescente , Adulto , Coinfección/microbiología , Femenino , Infecciones por Fusobacterium/microbiología , Humanos , Masculino , Persona de Mediana Edad , Tratamiento del Conducto Radicular , Adulto JovenRESUMEN
A brain abscess may result when dental infection reaches the brain through contiguous anatomic cavities such as the maxillary sinus, the ethmoid sinus and the orbital cavity. It is an important complication and should be treated aggressively. Such treatment would include the excision of the etiological factor, drainage and adjuvant antibiotic therapy. The present case concerns a 23 year old woman who presented at the General Hospital of Nova Iguaçu with complaints of pain in the right side of the face and was diagnosed with acute sinusitis. Antibiotics and analgesics were prescribed to treat the disease. However, after 10 days, she returned to the emergency room, presenting with proptosis of the right eyeball, subconjunctival haemorrhage, ophthalmoplegia and intense pain in the right orbit, in addition to headaches. After computed tomography was performed, she was diagnosed with a brain abscess in the frontal lobe with the involvement of the maxillary right first molar, the maxillary sinus, the ethmoid sinus and the orbital cavity. With culturing of the secretion, the growth of Pseudomonas aeruginosa colonies was evident. Treatment consisted of a craniotomy to drain the brain abscess, a Caldwell-Luc procedure to drain the right maxillary sinus, dental extraction and aggressive antibiotic therapy. After 6 weeks, the patient was discharged with no neurological sequelae.
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Absceso Encefálico/microbiología , Infecciones Bacterianas del Ojo/microbiología , Infección Focal Dental/microbiología , Sinusitis Maxilar/microbiología , Enfermedades Orbitales/microbiología , Infecciones por Pseudomonas/microbiología , Antibacterianos/uso terapéutico , Absceso Encefálico/diagnóstico , Absceso Encefálico/terapia , Craneotomía , Drenaje , Infecciones Bacterianas del Ojo/diagnóstico , Infecciones Bacterianas del Ojo/terapia , Femenino , Infección Focal Dental/diagnóstico , Infección Focal Dental/terapia , Lóbulo Frontal , Humanos , Sinusitis Maxilar/diagnóstico , Sinusitis Maxilar/terapia , Enfermedades Orbitales/diagnóstico , Enfermedades Orbitales/terapia , Infecciones por Pseudomonas/diagnóstico , Infecciones por Pseudomonas/terapia , Pseudomonas aeruginosa/aislamiento & purificación , Tomografía Computarizada por Rayos X , Enfermedades Dentales/tratamiento farmacológico , Extracción Dental , Adulto JovenRESUMEN
The aim of this study was to compare the use of beta-tricalcium phosphate (ß-TCP) (chronOS) with autogenous bone grafts alone in maxillary sinus elevation surgery. The test samples were ß-TCP alone, ß-TCP mixed with autogenous bone grafts (1:1), and autogenous bone grafts alone. Twelve maxillary sinuses were grafted with ß-TCP (group 1), nine with ß-TCP+autogenous bone graft (group 2), and 12 with autogenous bone graft (group 3). After 6 months, biopsies were obtained concurrent to the placement of dental implants; these were subjected to histomorphometric analysis and immunohistochemical analysis for runt-related transcription factor 2 (RUNX2) and vascular endothelial growth factor (VEGF). The average bone formation in group 1 was 46.3±11.6% in the pristine bone region, 47.6±9.9% in the intermediate region, and 44.8±22.1% in the apical region; in group 2, values were 35.0±15.8%, 32.5±13.7%, and 32.8±16.0%, respectively; in group 3, values were 43.1±16.0%, 31.0±13.0%, and 46.1±16.3%, respectively. Immunostaining of samples in group 2 showed high cellular activity and immature bone; this differed from groups 1 and 3, in which mature bone was demonstrated. Thus, this study showed that ß-TCP presents the same behaviour as autogenous bone graft, which makes it a good bone substitute.
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Sustitutos de Huesos/uso terapéutico , Trasplante Óseo/métodos , Fosfatos de Calcio/uso terapéutico , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Osteogénesis/fisiología , Elevación del Piso del Seno Maxilar/métodos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Femenino , Humanos , Inmunohistoquímica , Masculino , Estudios Prospectivos , Resultado del TratamientoRESUMEN
Takotsubo cardiomyopathy is an important condition that can be difficult to differentiate from acute coronary syndrome on the basis of clinical, electrocardiogram, and cardiac enzyme assessment alone. Although coronary angiography remains important in the acute assessment of patients with suspected takotsubo cardiomyopathy, cardiac magnetic resonance (CMR) has emerged over the last decade as an important non-invasive imaging tool in the diagnosis and follow-up of this condition. We present a review highlighting the CMR features of takotsubo cardiomyopathy and its complications with particular focus on differentiating this condition from acute myocardial infarction and myocarditis.
Asunto(s)
Imagen por Resonancia Magnética/métodos , Cardiomiopatía de Takotsubo/diagnóstico , Medios de Contraste , Diagnóstico Diferencial , Humanos , Cardiomiopatía de Takotsubo/fisiopatologíaRESUMEN
Childhood aneurysms are rare pathological findings. They present with a low incidence and have characteristic features. When occurred in the first year of life or when giant-sized, survival and recovery may be worst. Nevertheless outcomes are generally better than in adults. A surgical case of an eleven year old boy with excellent outcome is reported, with a subsequent review on the subject. Patients may present with classical subarachnoidal hemorrhage, but also with compressive signs with bigger and unruptured lesions. Initial management of these cases is basically the same of older patients, considering their age, weight and special intensive care for infants. Surgical principles, outcomes and etiology are analyzed.
Asunto(s)
Enfermedades de las Arterias Carótidas/cirugía , Arteria Carótida Interna/cirugía , Aneurisma Intracraneal/cirugía , Enfermedades de las Arterias Carótidas/patología , Arteria Carótida Interna/patología , Angiografía Cerebral , Niño , Humanos , Aneurisma Intracraneal/patología , Masculino , Procedimientos NeuroquirúrgicosRESUMEN
AIM: There has been much controversy concerning the surgical treatment of bilateral multiple intracranial aneurysms. Some authors advocate the use of two-stage surgery by bilateral pterional craniotomies and others advocate the one stage complete repair of all lesions using the contralateral approach. We analyze the surgical experience of one neurosurgeon using both approaches. METHODS: Sixty nine patients operated on for bilateral multiple intracranial aneurysms were divided in three groups: group A comprised 43 patients (62.3%) in whom all bilateral aneurysms were treated by one stage operation; group B comprised 9 patients (13.0%) in whom the clipping of the contralateral aneurysm it was not possible through the same approach, needing a second operation; group C comprised 17 patients (24.7%) in whom all bilateral multiple intracranial aneurysms were treated by two stage operations. RESULTS: According to the Glasgow Outcome Scale 61 cases (88.4%) had excellent or good results (GOS V, IV), 2 cases (2.9%) had fair results (GOS III) and 6 patients have died (GOS I). The results of group A were significantly better than in-group B (p<0,05 Fisher test), but they were not different in relation to the group C (p=0,439 Fisher test). Among the six deaths, only one was related to the surgical procedure. CONCLUSIONS: Under favorable clinical situations, as patients in H&H I to III, good brain conditions during the surgical procedure and aneurysms smaller than 1,5 cm, the contralateral surgical approach for the treatment of patients with bilateral multiple intracranial aneurysms can be used with advantages over the two stage approach.
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Aneurisma Intracraneal/patología , Aneurisma Intracraneal/cirugía , Procedimientos Neuroquirúrgicos/métodos , Adulto , Anciano , Encéfalo/fisiopatología , Femenino , Escala de Consecuencias de Glasgow , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos/mortalidad , Procedimientos Neuroquirúrgicos/normas , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
With the advent of the atomic force microscope (AFM), the study of biological samples has become more realistic because, in most cases, samples are not covered or fixed, which makes it possible to observe them while the cells are alive. This advantage of the AFM allowed the advent of a new invention: nanobiosensors using the cantilever (probe) of the AFM and, in this case, it is possible to observe the entering or exiting of specific molecules (including medications) from living cells. This is the smallest biosensor in the world, measuring about 100 microm long (about the width of a hair). Beyond sensing the area of interest with this biosensor, it is also possible to see the area and exactly what is occurring on it, in real time. This new tool will be very useful for several areas: molecular pharmacology, enzymology, physiology, molecular biology, biotechnology, biophysics, physical chemistry, analytical chemistry, and organic chemistry. This article discusses, mainly, the applications of this new technique to the field of pharmacology.
Asunto(s)
Microscopía de Fuerza Atómica/métodos , Farmacología/métodos , Técnicas Biosensibles/métodos , Microscopía Electrónica de Rastreo/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Saccharomyces cerevisiaeRESUMEN
MRI methods currently used for bolus tracking in the myocardium, such as saturation recovery turbo-fast low-angle shot (FLASH) (srTFL), are limited by signal intensity (SI) saturation at high contrast agent (CA) concentrations. By using T1 fast acquisition relaxation mapping (T1 FARM), a Gd-DTPA bolus (0.075 vs. 0.025 mmol/kg) may be injected without causing saturation. This study tested the feasibility of in vivo T1 FARM bolus tracking under rest/stress conditions in seven beagles with multiple permanently occluded branches of the left anterior descending (LAD) coronary artery. Although it underestimated the myocardial perfusion reserve (MPR) measured ex vivo using radioactive microspheres (mean +/- SEM; 3.60 +/- 0.26), the MPR determined upon application of the modified Kety model (1.86 +/- 0.10) enabled distinction between normal and infarcted tissue. The partition coefficient (lambda) estimated at rest and stress using the modified Kety model underestimated ex vivo radioactive measurements in infarcted tissue (0.25 +/- 0.01 vs. 0.26 +/- 0.01 vs. 0.79 +/- 0.08 ml/g, P < 0.0001) yet was accurate in normal tissue (0.28 +/- 0.01 vs. 0.30 +/- 0.01 vs. 0.33 +/- 0.01 ml/g, P = NS). Thus, although unsuitable for myocardial viability assessment, T1 FARM bolus tracking shows potential for assessment of myocardial perfusion.
Asunto(s)
Medios de Contraste , Circulación Coronaria/fisiología , Gadolinio DTPA , Aumento de la Imagen , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Infarto del Miocardio/diagnóstico , Animales , Perros , Femenino , Infarto del Miocardio/fisiopatología , Valores de Referencia , Sensibilidad y EspecificidadRESUMEN
It has previously been shown that the distribution volume of Gd-DTPA (lambda) in infarcted, canine myocardium is higher than that of normal tissue. The purpose of this study was to determine whether stunned myocardium exhibits increased lambda. Stunning was produced in beagles by means of 30 min LAD occlusion followed by 3 weeks (n = 4) reperfusion. Gd-DTPA was infused at each imaging session and lambda determined in vivo using a saturation recovery turboFLASH sequence; cine imaging was used to assess ventricular wall thickening (%WT). (201)Tl uptake was used as an independent assessment of viability. %WT data confirmed that the brief insult caused prolonged, yet reversible, regional contractile dysfunction in each animal. %WT was not significantly different from baseline values by 3 weeks post-reflow. Normal (201)Tl uptake confirmed the absence of infarction. The lambda of stunned tissue (lambda = 0.381 +/- 0.030 ml/g) was not elevated above that of normal tissue (lambda = 0.398 +/- 0.027 ml/g, P = NS), at any time point studied, in vivo. These data suggest that an increase in lambda is a specific indicator of irreversible damage.
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Gadolinio DTPA , Imagen por Resonancia Magnética/métodos , Daño por Reperfusión Miocárdica/fisiopatología , Aturdimiento Miocárdico/fisiopatología , Animales , Medios de Contraste , Modelos Animales de Enfermedad , Perros , Femenino , Imagenología Tridimensional , Supervivencia TisularRESUMEN
At present, accurate assessment of the extent of myocardial viability after acute myocardial infarction is limited due to the spatial resolution of currently available imaging modalities. MR cardiac imaging, with its superior spatial resolution, would be used if viable and infarcted tissue could be separated based on signal intensity. In infarcted tissue, cell membrane breakdown allows the entry of the MR contrast agent Gd-DTPA which is normally extracellular. The increased space for Gd-DTPA distribution (partition coefficient, lambda) in this infarcted tissue results in increased Gd-DTPA concentration and hence increased signal intensity on T1-weighted MR images. In a canine model of ischemia/reperfusion injury, the partition coefficient in infarcted tissue increased as early as 1 min post reperfusion. lambda in infarcted tissue stayed increased over that in normal tissue for at least 8 weeks. The accuracy of contrast-enhanced MRI was confirmed by results of 201Tl SPECT and a cine MRI dobutamine wall motion study in a patient 1 week after an acute myocardial infarction. Thus, contrast-enhanced MRI shows great promise for the non-invasive determination of myocardial viability after acute myocardial infarction.
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Supervivencia Celular/fisiología , Medios de Contraste , Gadolinio DTPA , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/cirugía , Reperfusión Miocárdica , Miocardio/citología , Miocardio/metabolismo , Animales , Biomarcadores/análisis , Ensayos Clínicos como Asunto , Predicción , Humanos , Imagen por Resonancia Magnética , Modelos Cardiovasculares , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
AIM: To assess the long-term safety and efficacy of the H1-receptor antagonist mizolastine in the symptomatic treatment of chronic urticaria (CU). BACKGROUND: Mizolastine is a novel second generation antihistamine with additional anti-inflammatory properties which has been shown to be effective in this condition as well as in allergic rhinitis. As the drug is used for chronic treatment, a detailed study of its efficacy and safety over a prolonged period was warranted. METHODS: This open label multicentre trial recruited 211 patients suffering from CU (67% female; mean age 40+/-13 years), with > or = 1 episode/week if untreated. After a 7-day placebo run-in period, patients received mizolastine (10 or 15 mg) for 12 months. Efficacy was assessed by the patient using daily diary cards and overall condition evaluation at study visits. Clinicians also assessed the same parameters at each visit, and gave a global assessment at study termination. Safety was assessed by monitoring adverse events and laboratory parameters. Cardiac safety was monitored every 4 months using 12-lead ECGs, with particular attention to QT intervals. RESULTS: The trial was completed by 127 patients. Mizolastine reduced overall discomfort from the second week of therapy, and reduced itching and the number and size of wheals, as assessed by the patients. The clinician's assessment of the proportion of patients with > 10 wheals decreased from 42% to 28% after 2 months. Clinical assessment also indicated that itch intensity and angioedema were improved by mizolastine, and the improvement was sustained throughout the trial. The investigators estimated that 70% of patients benefited from therapy. There were no drug-related serious adverse events during the study. The cardiac repolarization assessed according to the QTc intervals was not modified during prolonged administration. CONCLUSION: Mizolastine improves CU symptoms, and these improvements are sustained over 12 months with no loss of drug sensitivity. No specific side-effects are associated with its long-term use in the current study.
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Bencimidazoles/uso terapéutico , Antagonistas de los Receptores Histamínicos H1/uso terapéutico , Urticaria/tratamiento farmacológico , Adulto , Bencimidazoles/efectos adversos , Enfermedad Crónica , Femenino , Antagonistas de los Receptores Histamínicos H1/efectos adversos , Humanos , MasculinoRESUMEN
Previous studies in a model of ischemia/reperfusion using a constant infusion of Gd-DTPA have shown that distribution volume (lambda) is increased in infarcted myocardial tissue. This study examined this technique in the setting of permanent coronary artery occlusion. Ten beagles underwent permanent occlusion of a coronary artery for 2 days (N = 3), 1 week (N = 4), or 3 weeks (N = 3). Imaging was performed at 2 days and, depending on the length of occlusion, 1 week, 2 weeks, and 3 weeks to follow changes in lambda in vivo. At sacrifice, (201)Tl was injected and the extent of the hyperenhanced region was compared to pathology. lambda was increased in infarcted tissue by 2 days post occlusion and this increase persisted for 3 weeks. At sacrifice, lambda correlated strongly with (201)Tl uptake (r = -0.86 to -0.95, P < 0.05; i.e., lambda increased in infarcted tissue) and the size of the hyperenhanced region was comparable to pathological infarct size (slope 1.006, r = 0.96, P < 0.0001). Thus, beyond 2 days after coronary occlusion, MRI, during a constant infusion of Gd-DTPA, can assess myocardial viability regardless of the success of reperfusion. Magn Reson Med 44:309-316, 2000.
Asunto(s)
Medios de Contraste , Enfermedad Coronaria/fisiopatología , Gadolinio DTPA , Imagen por Resonancia Magnética/métodos , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/fisiopatología , Análisis de Varianza , Animales , PerrosRESUMEN
This study assessed the accuracy and feasibility of magnetic resonance imaging (MRI) during a constant infusion of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) for the determination of myocardial viability in patients with recent acute myocardial infarction (AMI). Nine patients were studied within 10 days of AMI. Rest-redistribution 201Thallium (201Tl) single photon emission computed tomography (SPECT) was used as a gold standard for viability. Using MRI, regional perfusion was assessed using dynamic imaging during a bolus injection of Gd-DTPA and viability was assessed during a continuous infusion. Finally, cine MR images were acquired at baseline, during low-dose dobutamine infusion and after recovery. To assess viability, the left ventricle was divided into 16 segments and signal intensity in corresponding MRI and redistribution SPECT segments were compared. Wall thickening index (WTI) was determined at each step during the dobutamine study. The results revealed that in five patients, reduced perfusion in infarcted regions was observed qualitatively during dynamic first pass imaging. There was a significant inverse correlation between 201Tl uptake and MRI signal intensity, i.e. infarcted tissue (low 201Tl uptake) had increased MR signal intensity. Segments were separated into normal (201Tl uptake > 90%) and infarcted (< 601%). lnfarcted MRI segments had greater signal intensity than normal segments (179 +/- 50 vs. 102 +/- 14%; P < 0.0001). WTI in normal segments increased by 18 +/- 8.5% (P < 0.0001) from baseline to 10 microg/kg per min of dobutamine while infarcted tissue WTI decreased 2.8 +/- 7.2% (P = 0.17). Thus regions of myocardium that were infarcted as defined by reduced 201Tl uptake and absent contractile reserve showed greatly increased MRI signal intensity during a constant infusion of Gd-DTPA. The use of MRI during a constant infusion of Gd-DTPA is accurate and feasible for the determination of myocardial necrosis in a clinical setting.
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Gadolinio DTPA , Imagen por Resonancia Magnética/métodos , Infarto del Miocardio/patología , Adulto , Cardiotónicos , Medios de Contraste/administración & dosificación , Dobutamina , Prueba de Esfuerzo , Gadolinio DTPA/administración & dosificación , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Contracción Miocárdica/efectos de los fármacos , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Necrosis , Radioisótopos de Talio , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
It was previously shown in a canine model of ischemia/reperfusion injury that the partition coefficient of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) (lambda) increases in infarcted tissue. That previous study used a non-magnetic resonance imaging (MRI) method to measure lambda and only investigated reperfusion times from 2 hr to 3 weeks. This study presents evidence suggesting that lambda starts to increase as early as 1 min after reperfusion of a 2 hr occlusion and continues to rise for up to 2 hr or more; lambda stays increased as late as 8 weeks, reaching peak values at 1-11 days and subsequently decreasing. It was also demonstrated that lambda can be accurately measured in vivo using a saturation recovery turbo fast low-angle shot (FLASH) sequence. The results of this study show that MRI during a constant infusion of Gd-DTPA has great potential for the non-invasive determination of myocardial viability as early as 1 min to as late as 8 weeks following reperfusion of acute myocardial infarction.
Asunto(s)
Medios de Contraste , Gadolinio DTPA , Infarto del Miocardio/diagnóstico , Daño por Reperfusión Miocárdica/diagnóstico , Supervivencia Tisular/fisiología , Animales , Circulación Coronaria/fisiología , Perros , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/fisiopatologíaRESUMEN
Current MRI bolus tracking techniques, such as saturation recovery Turbo-FLASH (srTFL), suffer from signal saturation at high contrast concentrations. In this study T1 Fast Acquisition Relaxation Mapping (T1 FARM) was compared to srTFL. In phantoms, T1 FARM maps were linear with [Gd-DTPA] up to 7.0 mmol/L while srTFL images saturated above 2.0 mmol/L. In the canine left ventricle, blood concentration curves determined from T1 FARM saturated with bolus injections exceeding 0.075 mmol/kg, while srTFL curves saturated above 0.025 mmol/kg of Gd-DTPA. Also, T1 FARM improved contrast-to-noise ratio in tissue concentration curves since higher contrast concentrations could be measured without saturating.
Asunto(s)
Medios de Contraste/farmacocinética , Gadolinio DTPA/farmacocinética , Imagen por Resonancia Magnética/métodos , Fantasmas de Imagen , Animales , Modelos Animales de Enfermedad , Perros , Relación Dosis-Respuesta a Droga , Femenino , Gadolinio DTPA/administración & dosificación , Ventrículos Cardíacos/anatomía & histología , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/instrumentación , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
Substance P has various immunomodulatory effects, including in vitro modification of lymphocyte proliferation and cytokine release. Elevated levels of substance P and increased staining of substance P-positive nerve fibres have been reported in atopic dermatitis patients. We examined fluoresceinated substance P binding to a range of lymphocyte subsets and compared the results in atopic dermatitis, non-atopic psoriasis patients and normal controls. Fluoresceinated substance P and phycoerythrin-labelled monoclonal antibodies to CD3, CD4, CD8, CD57, CD19 and CD14 were incubated in duplicate with Ficoll-Hypaque separated peripheral blood mononuclear leukocytes. With flow cytometry the fluoresceinated substance P-positive cells were identifiable as a peak of positively fluorescent cells, and the percentages of positive cells were measured. We have demonstrated binding of fluoresceinated substance P to all subsets examined, with significantly less binding to atopic dermatitis CD3-, CD8- and CD57-positive cells. This may affect cytokine release and hence be important in the pathogenesis of atopic dermatitis.
Asunto(s)
Dermatitis Atópica/sangre , Linfocitos/metabolismo , Sustancia P/sangre , Adolescente , Adulto , Femenino , Citometría de Flujo , Fluoresceína , Fluoresceínas , Humanos , Subgrupos Linfocitarios , Masculino , Persona de Mediana Edad , Ficoeritrina , Unión Proteica , Psoriasis/sangreRESUMEN
The arterious venous oxygen difference (AVDO2) due to the close relationship with cerebral metabolic rate of oxygen and cerebral blood flow shows metabolic alterations that occur in some pathological situations in the brain including subarachnoid haemorrhage. The AVDO2 was calculated by the Fick equation and the results evaluated by the Glasgow outcome scale. Measurements of arteriojugular oxygen difference were carried out in 30 patients with subarachnoid haemorrhage due to rupture of intracranial aneurysms, as an attempt to monitor the relationship between changes in AVDO2, clinical picture, and evolution of the patients. The subarachnoid haemorrhage was diagnosed by CT scan in 17 patients and by lumbar punction in 13 and the diagnosis of arterial vasospasm was carried out by clinical evaluation and confirmed by four vessels angiogram in only eight patients. Eighteen patients were admitted with Hunt & Hess (H&H) I/II, seven with H&H III and five with H&H IV/V. Nineteen patients had AVDO2 normal and this group had three deaths; five patients had AVDO2 continuously low with three deaths; and six patients had AVDO2 continuously high with two deaths. The patients with normal AVDO2 had better prognosis and clinical evolution than the patients with abnormal values of AVDO2. In conclusion, AVDO2 measurements could not be correlated with the diagnosis of vasospasm, but was useful in the early identification of metabolic changes that occur after subarachnoid haemorrhage and could be used as an supplementary monitoring in the clinical evaluation of patients with this pathology.