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The study of high-velocity particle-laden flow interactions is of importance for the understanding of a wide range of natural phenomena, ranging from planetary formation to cloud interactions. Experimental observations of particle dynamics are sparse given the difficulty of generating high-velocity flows of many particles. Ejecta microjets are micron-scale jets formed by strong shocks interacting with imprinted surfaces to generate particle plumes traveling at several kilometers per second. As such, the interaction of two ejecta microjets provides a novel experimental methodology to study interacting particle streams. In this Letter, we report the first time sequences of x-ray radiography images of two interacting tin ejecta microjets taken on a platform designed for the OMEGA Extended Performance (OMEGA EP) laser. We observe that the microjets pass through each other unattenuated for the case of 11.7±3.2 GPa shock pressures and jet velocities of 2.2±0.5 km/s but show strong interaction dynamics for 116.0±6.1 GPa shock pressures and jet velocities of 6.5±0.5 km/s. We find that radiation-hydrodynamic simulations of the experiments are able to capture many aspects of the collisional behavior, such as the attenuation of jet velocity in the direction of propagation, but are unable to match the full spread of the strongly interacting cloud.
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INTRODUCTION: Metabolic abnormalities are frequently reported in HIV infection. They were mainly related to the chronic infection and the use of antiretroviral therapy. OBJECTIVE: Describe the epidemiological, clinical, laboratory and treatment features of people living with HIV (PLHIV) on antiretroviral therapy and determine the prevalence of metabolic syndrome and its associated factors. MATERIALS AND METHODS: We conducted a cross-sectional, descriptive and analytical study in the service of Infectious Diseases of the University Hospital of Monastir. We included all PLHIV on antiretroviral therapy for at least 3 months. Biological explorations based on metabolic parameters were performed systematically for all patients after informed consent. Metabolic syndrome was assessed according to the definitions of the International Diabetes Federation (IDF) in 2005. We divided the patients into two groups: Group A: PLHIV with metabolic syndrome (n=19) and Group B: PLHIV without metabolic syndrome (n=51). RESULTS: We included in this study 70 PLVIH. The metabolic syndrome was noted in 19 cases (27.1%). The average age was 43.7 years in group A and 36.7 years in group B. Gender distribution were uniform in the two groups (P=0.4). HIV infection has been evolving for 9.7 and 5.8 years respectively in group A and B, P=0.017. Body mass index (BMI) was significantly higher in group A (26.4 vs 23.5kg/m2, P=0.008). Two patients in group A (10.5%) and 14 patients in group B (27.4%) had a low CD4 count (<200/mm3). Protease inhibitor regimens were prescribed in five cases (26.3%) in group A and 26 cases (50.9%) in group B. In multivariate models, Age over 40 (OR=9.9, 95% CI 2.4-40.6, P=0.001) and BMI ≥25 Kg/m2 (OR=8.47, 95% CI 1.94-36.8, p=0.004) were both independently associated with the presence of the metabolic syndrome. CONCLUSION: Metabolic syndrome is common among PLHIV on antiretroviral therapy. The identification of factors associated is a main parameter for early detection of metabolic risk and personalized management.
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Infecções por HIV , Síndrome Metabólica , Adulto , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Síndrome Metabólica/epidemiologia , Prevalência , Fatores de Risco , Tunísia/epidemiologiaRESUMO
Temocillin concentrations were determined in the gallbladder bile and/or common bile duct bile obtained intraoperatively from 20 patients, and in the T-tube bile of 5 postoperative patients. Blood samples were also obtained for determining the concomitant serum antibiotic concentrations. In 6 patients with cholelithiasis, but without common bile duct obstruction or acute infection, the mean temocillin concentrations were 890 mg/L in gallbladder bile and 1030 mg/L in common bile duct bile. In the group of 6 patients with common bile duct obstruction, the antibiotic concentrations ranged between 5.6 and 88 mg/L (mean 38.8 mg/L) in gallbladder bile and between 'undetectable' and 700 mg/L in common bile duct bile. In patients with biliary sepsis, a further reduction in temocillin bile concentrations was observed, and postoperatively, the T-tube bile temocillin concentrations were in the range of 21 to 460 mg/L (mean 130 mg/L). The clinical efficacy of temocillin in the 7 patients with acute cholecystitis was judged to be satisfactory. Our results suggest that temocillin may be considered as a potentially useful antibiotic in the treatment of patients with biliary tract sepsis caused by susceptible organisms.
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Doenças Biliares/tratamento farmacológico , Colecistite/tratamento farmacológico , Penicilinas/uso terapêutico , Adulto , Idoso , Bile/metabolismo , Feminino , Vesícula Biliar/metabolismo , Hepatite/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Penicilinas/metabolismoRESUMO
From 1980 to 1986, during the Lebanon war, five patients with missile embolization were seen at the American University of Beirut Medical Center. Three had entry in the heart or thoracic aorta with peripheral embolization, and two had entry in the internal carotid artery and inferior vena cava with embolization to the middle cerebral artery and heart, respectively. Embolization was suspected when, in the absence of an exit, routine x-ray films showed the missile in a distant location. Angiography and echocardiography confirmed the diagnosis. Peripheral arterial emboli were extracted while cerebral and venous emboli were kept, as they caused transient symptoms and remained silent.
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Embolia/etiologia , Corpos Estranhos/complicações , Migração de Corpo Estranho/complicações , Ferimentos por Arma de Fogo/complicações , Adolescente , Angiografia/métodos , Artérias Cerebrais , Embolia/diagnóstico por imagem , Feminino , Artéria Femoral , Ventrículos do Coração , Humanos , Artéria Ilíaca , Masculino , Pessoa de Meia-Idade , Técnica de SubtraçãoRESUMO
Although positron emission tomography (PET) imaging is now recognized as a useful tool for staging intermediate and high-grade non-Hodgkin's lymphoma (NHL), few data are available regarding its accuracy in low grade NHL. We therefore studied 36 patients with histologically proven low-grade NHL. Whole-body 2-(fluorine-18) fluoro-2-deoxy-D-glucose (FDG) PET was performed at the time of initial diagnosis (n = 21) or for disease recurrence (n = 15) prior to any treatment. PET results were compared to those of physical examination and computed tomography (CT). PET studies were read without knowledge of any clinical data. Any focus of increased activity was described and given a probability of malignancy using a 5 point-scale (0: normal to 4: definitively malignant). An individual biopsy was available for a total of 31 lesions. The sensitivity and specificity were 87% and 100% for FDG-PET, 100% and 100% for physical examination and 90% and 100% for CT respectively. In addition, 42 of 97 peripheral lymph node lesions observed by FDG-PET were clinically undetected, whereas the physical examination detected 23 additional nodal lesions. PET and CT both indicated 12 extranodal lymphomatous localizations. FDG-PET showed 7 additional extranodal lesions while 5 additional unconfirmed lesions were observed on CT. Regarding bone marrow infiltration, PET and biopsy were concordant in 24 patients with 11 true positive (TP) and 13 true negative (TN). However PET was FN in 11 patients and no biopsy was performed in one patient. The combination PET/CT/physical examination seems to be more sensitive than the conventional approach for staging low grade NHL. Its sensitivity however is unacceptably low for diagnosing bone marrow infiltration.
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Medula Óssea/diagnóstico por imagem , Fluordesoxiglucose F18 , Linfonodos/diagnóstico por imagem , Linfoma não Hodgkin/diagnóstico por imagem , Compostos Radiofarmacêuticos , Adulto , Idoso , Medula Óssea/patologia , Reações Falso-Negativas , Feminino , Humanos , Fígado/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Linfonodos/patologia , Linfoma não Hodgkin/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/métodos , Sensibilidade e Especificidade , Baço/diagnóstico por imagem , Tomografia Computadorizada de Emissão/métodosRESUMO
We performed this study in order to evaluate the diagnostic accuracy of whole-body fluorodeoxyglucose positron emission tomography (FDG PET) imaging and somatostatin receptor scintigraphy (SRS) for localizing primary carcinoid tumours and evaluating the extent of the disease. A secondary aim was to correlate those findings with the histological characteristics of the lesions. FDG PET was performed in 17 patients and SRS in 16. All patients had pathologically proven carcinoids. All lesions were verified by histopathological analysis or by follow-up. Ki-67 and p53 expression were assessed as an indicator of the tumours' aggressiveness. FDG PET correctly identified 4/7 primary tumours and 8/11 metastatic spreads, as compared to six and 10 respectively, for SRS. Most tumours were typical carcinoids with low Ki-67 expression. No correlation was found between the histological features and the tracer's uptake. We conclude that SRS remains the modality of choice for evaluating patients with carcinoid tumours, regardless of their proliferative activity. FDG PET should be reserved to patients with negative results on SRS.
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Tumor Carcinoide/diagnóstico por imagem , Tumor Carcinoide/patologia , Fluordesoxiglucose F18 , Octreotida/análogos & derivados , Ácido Pentético/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Tumor Carcinoide/diagnóstico , Tumor Carcinoide/secundário , Reações Falso-Negativas , Feminino , Humanos , Antígeno Ki-67/análise , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Cintilografia , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Sensibilidade e Especificidade , Método Simples-Cego , Estatística como Assunto , Proteína Supressora de Tumor p53/análiseRESUMO
Whole-body metabolic information provided by 18F-FDG PET could help in the evaluation of lymphoma patients at diagnosis and follow-up. We studied 60 patients, 42 at initial presentation and 18 for disease recurrence (23 aggressive non-Hodgkin's lymphoma, 21 low-grade non-Hodgkin's lymphoma and 16 Hodgkin's disease). All patients underwent a clinical examination, computed tomography (CT) and a non-attenuated PET scan within 1 week. The patients received 222-296 MBq (6-8 mCi) 18F-FDG intravenously and emission scans were recorded 45-90 min later. 18F-FDG PET detected more lymph nodes than the clinical examination or CT, but this rarely resulted in upstaging (two patients). The concordance between PET and CT for the evaluation of the spleen, liver and digestive tract was quite good. Discordance was noted in 12 patients for the evaluation of bone marrow infiltration, but confirmation by MRI or focal biopsy was not always obtained. We conclude that non-attenuated 18F-FDG PET is an easy and efficient whole-body method for the evaluation of patients with lymphomas. Compared with conventional techniques, however, it does not appear to offer much improvement for staging but provides a satisfactory base for follow-up.
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Doença de Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/diagnóstico por imagem , Sistema Digestório/diagnóstico por imagem , Fluordesoxiglucose F18 , Seguimentos , Humanos , Fígado/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Baço/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Contagem Corporal TotalRESUMO
Between April 1980 and June 1986, 274 patients underwent mitral valve replacement (MVR) with the Björk-Shiley (BS) standard disc mitral valve prosthesis at the American University of Beirut Medical Center (AUBMC). Eleven patients (3.9%) presented 6-41 months after surgery with prosthetic valve dysfunction due to thrombosis. Inadequate control of anticoagulation was the major factor predisposing to thrombosis in all except one. All patients had documented rheumatic valvular disease. Nine patients were operated on an emergency basis and two died before any surgical intervention was possible. Thrombectomy was performed on six patients with four survivors and MVR in three with two survivors. Two patients died intraoperatively (22%). Three pregnant patients underwent mechanical declotting; pregnancy was terminated by abortion in 2 and by caesarean section and live birth in one. We conclude that implantation of the BS mitral valve prosthesis mandates emphasis on anticoagulation and the difficulty encountered with continuous anticoagulant therapy in pregnancy.
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Próteses Valvulares Cardíacas , Trombose/etiologia , Adolescente , Adulto , Anticoagulantes/administração & dosagem , Feminino , Próteses Valvulares Cardíacas/efeitos adversos , Humanos , Recém-Nascido , Masculino , Valva Mitral , Complicações Pós-Operatórias , Gravidez , Complicações Cardiovasculares na Gravidez/etiologia , Complicações Cardiovasculares na Gravidez/cirurgia , Reoperação , Trombose/cirurgiaAssuntos
Aorta/cirurgia , Prótese Vascular , Heparina , Polímeros , Veia Cava Inferior/cirurgia , Adulto , Idoso , Animais , Tecido Conjuntivo , Detergentes , Cães , Fibrina , Humanos , Masculino , Veia Safena , Doenças Vasculares/cirurgiaAssuntos
Artérias , Dextroanfetamina , Embolia/tratamento farmacológico , Dedos/irrigação sanguínea , Transtornos Relacionados ao Uso de Substâncias/complicações , Adulto , Angiografia , Cateterismo , Dextranos/uso terapêutico , Heparina/uso terapêutico , Humanos , Injeções Intra-Arteriais , Masculino , Papaverina/uso terapêuticoAssuntos
Mortalidade Hospitalar , Infarto do Miocárdio/mortalidade , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Líbano/epidemiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/terapia , Estudos Retrospectivos , Fatores de Risco , Inquéritos e Questionários , Análise de SobrevidaRESUMO
A sharp interface immersed boundary method for simulating incompressible viscous flow past three-dimensional immersed bodies is described. The method employs a multi-dimensional ghost-cell methodology to satisfy the boundary conditions on the immersed boundary and the method is designed to handle highly complex three-dimensional, stationary, moving and/or deforming bodies. The complex immersed surfaces are represented by grids consisting of unstructured triangular elements; while the flow is computed on non-uniform Cartesian grids. The paper describes the salient features of the methodology with special emphasis on the immersed boundary treatment for stationary and moving boundaries. Simulations of a number of canonical two- and three-dimensional flows are used to verify the accuracy and fidelity of the solver over a range of Reynolds numbers. Flow past suddenly accelerated bodies are used to validate the solver for moving boundary problems. Finally two cases inspired from biology with highly complex three-dimensional bodies are simulated in order to demonstrate the versatility of the method.
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Two patients with known intracranial aneurysms (ICA) received electroconvulsive therapy (ECT). The first patient received ECT 4 years after the clipping of a right middle cerebral artery aneurysm. Treatment with esmolol failed to completely prevent an increase in blood pressure, but she did well nonetheless. The second patient underwent clipping of a basilar artery aneurysm 11 years before ECT. At the time of ECT, angiography showed a right paraophthalmic artery aneurysm. He received esmolol before each ECT, and, like the first patient, still had significant peri-ictal increases in his blood pressure, but otherwise tolerated the procedure well. Our experience and previously published literature indicate that even with pretreatment, patients often sustain significant increases in their blood pressure. However, this has not been accompanied by any morbidity. Possible guidelines for the management of ICA in association with ECT are discussed.
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Eletroconvulsoterapia/efeitos adversos , Aneurisma Intracraniano/fisiopatologia , Agonistas Adrenérgicos beta/farmacologia , Agonistas Adrenérgicos beta/uso terapêutico , Idoso , Pressão Sanguínea/efeitos dos fármacos , Transtorno Depressivo/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Propanolaminas/farmacologia , Propanolaminas/uso terapêuticoRESUMO
An investigation was carried out on 13 ASA class 1 or 2 adult patients undergoing laparoscopic cholecystectomy. Throughout laparoscopy, the end-tidal PCO2 was continuously monitored by capnography and the arterial hemoglobin oxygen saturation by pulse oximetry. Also, repeated measurements of arterial blood gases were done. Ventilation was controlled using an inspired oxygen concentration of 33% and tidal volume of 10 to 15 ml/kg at a rate of 10-14/min. The report showed that both the mean end-tidal PCO2 and arterial PCO2 progressively increased following carbon dioxide insufflation, to reach a maximal value after 30 min, with no significant change in the arterial-alveolar PCO2 gradient. Also, the arterial PO2 significantly decreased, and the hemoglobin oxygen saturation was always above 98% whether monitored by arterial blood gas analysis or by pulse oximetry. The results suggest that end-tidal capnography and pulse oximetry can be used as noninvasive techniques for monitoring arterial oxygenation and carbon dioxide elimination during laparoscopic cholecystectomy.
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Dióxido de Carbono/análise , Dióxido de Carbono/metabolismo , Colecistectomia Laparoscópica , Monitorização Intraoperatória , Oximetria , Oxigênio/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestesia Geral , Dióxido de Carbono/administração & dosagem , Dióxido de Carbono/sangue , Colelitíase/cirurgia , Hemoglobinas/análise , Humanos , Insuflação , Pessoa de Meia-Idade , Oxigênio/administração & dosagem , Respiração Artificial , Volume de Ventilação Pulmonar , Fatores de Tempo , Relação Ventilação-PerfusãoRESUMO
An investigation of end-tidal carbon dioxide tension changes was carried out in 19 healthy adult patients undergoing laparoscopic cholecystectomy. Following induction of anaesthesia, and throughout surgery, the end-tidal carbon dioxide tension was continuously monitored by capnography. The value following carbon dioxide insufflation increased with time to reach a maximum value after 40 min. Correlation of the individual maximum end-tidal carbon dioxide tension during laparoscopy with the corresponding baseline value prior to carbon dioxide insufflation showed a positive linear relationship (correlation coefficient 0.86). The correlation showed that an end-tidal carbon dioxide tension of 5.32 kPa (40 mmHg) can be achieved during laparoscopy when the baseline value is adjusted to around 4.0 kPa (30 mmHg).
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Dióxido de Carbono , Colecistectomia Laparoscópica , Volume de Ventilação Pulmonar , Adulto , Anestesia Geral , Dióxido de Carbono/administração & dosagem , Humanos , Insuflação , Pessoa de Meia-Idade , Fatores de TempoRESUMO
BACKGROUND AND OBJECTIVES: Accurate staging is essential in order to determine appropriate treatment in Hodgkin's disease (HD). (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) offers the advantage of metabolic imaging that is largely independent of morphologic criteria. In the present study we evaluated the role of (18)F-FDG PET compared to routine procedures for the staging of patients with HD. DESIGN AND METHODS: Thirty-three patients with HD underwent standard staging procedures (clinical examination, laboratory screening, chest X-ray, computed tomography (CT) of the chest and abdomen and bilateral bone marrow biopsies) and a whole-body (18)F-FDG PET study. In clinical examination, an isolated lymph node > 1 cm or multiple lymph nodes > or = 1 cm in size were considered abnormal. Positive findings at both clinical examination or CT and (18)F-FDG PET were regarded as actual locations of disease. Negative findings with both methods were regarded as true negative (no involvement by HD). In cases of discrepancy, response to treatment and follow-up data were used to assess the overall accuracy of the patient's original evaluation. RESULTS: Completely concordant results in lymph node staging were observed in 20 patients. The two staging procedures indicated complementary information in 1 patient. Conventional staging indicated more pathologic lymph node areas in 6 patients (at least 1 false positive). (18)F-FDG PET showed more sites in 6 patients. The sensitivity of (18)F-FDG PET in detecting all known pathologic lymph nodes was 83% for peripheral lymph nodes, 91% for thoracic lymph nodes and 75% for abdominal and pelvic lymph nodes. Conventional staging procedures and (18)F-FDG PET indicated the same tumor stage in 26 patients. Based on (18)F-FDG PET, downstaging was suggested in 4 patients, including a biopsy-proven case. However in 1 of these cases this was incorrect. (18)F-FDG PET suggested upstaging in 3 patients. Based on conventional staging or (18)F-FDG PET the same treatment strategy was defined in 32 patients. In one patient (18)F-FDG PET downstaged disease extension (stage IIIA-->IIA) that would have suggested radiotherapy as a possible treatment option. INTERPRETATION AND CONCLUSIONS: (18)F-FDG PET provides an easy and efficient whole-body method for the evaluation of patients with HD. (18)F-FDG PET never missed tumor masses >1 cm. (18)F-FDG PET detected additional sites of disease not seen by conventional procedures and identified absence of disease in some sites suspected to be involved. However, in our patients this did not translate into changes in treatment strategy.
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Doença de Hodgkin/diagnóstico , Estadiamento de Neoplasias/métodos , Adolescente , Adulto , Idoso , Feminino , Fluordesoxiglucose F18 , Doença de Hodgkin/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada de Emissão/métodosRESUMO
BACKGROUND: Although PET has been shown to be highly sensitive in the primary staging of lymphoma, previous studies with small numbers of patients indicated that low-grade NHL may not always be adequately detected by PET. We undertook this study to determine factors influencing the detection of lesions by PET in low-grade NHL and to evaluate the utility of PET in this indication. PATIENTS AND METHODS: Forty-two patients underwent conventional staging procedures (clinical examination, oto-rhino-laryngologic examination, computed tomography of the chest, abdomen and pelvis, gastroscopy and bone marrow biopsy as well as whole-body non-attenuation corrected 18F-FDG-PET RESULTS: PET detected 40% more abnormal lymph node areas than conventional staging in follicular lymphoma but was inappropriate for the staging of small lymphocytic lymphoma where it detected less than 58% of abnormal lymph node areas. PET showed more lesions than conventional staging for peripheral (34% more lymph node areas detected) and thoracic lymph node (39% more) areas but not for abdominal or pelvic lymph nodes (26% fewer areas detected). The sensitivity to detect bone marrow infiltration was unacceptably low for PET. In contrast, PET was as effective as standard procedures for the detection of other extranodal localizations, although a few localizations were detected only by PET and a few others only by conventional procedures. CONCLUSIONS: PET may contribute to the management of patients with low-grade follicular NHL. For the other low-grade lymphoma subtypes, the role of PET is less evident. Further studies using PET to evaluate the results of treatment or to diagnose disease recurrence are warranted in low-grade follicular NHL.