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1.
Commun Biol ; 7(1): 410, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575730

RESUMO

Climate change is restructuring natural ecosystems. The direct impacts of these events on biodiversity and community structure are widely documented, but the impacts on the genetic variation of populations remains largely unknown. We monitored populations of Acropora coral on a remote coral reef system in northwest Australia for two decades and through multiple cycles of impact and recovery. We combined these demographic data with a temporal genetic dataset of a common broadcast spawning corymbose Acropora to explore the spatial and temporal patterns of connectivity underlying recovery. Our data show that broad-scale dispersal and post-recruitment survival drive recovery from recurrent disturbances, including mass bleaching and mortality. Consequently, genetic diversity and associated patterns of connectivity are maintained through time in the broader metapopulation. The results highlight an inherent resilience in these globally threatened species of coral and showcase their ability to cope with multiple disturbances, given enough time to recover is permitted.


Assuntos
Antozoários , Resiliência Psicológica , Animais , Antozoários/genética , Ecossistema , Recifes de Corais , Dinâmica Populacional
2.
Arch Pediatr ; 26(8): 459-465, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31630903

RESUMO

Thoracic ultrasound (TUS) is increasingly studied in neonatal respiratory distress but chest x-ray (CXR) remains the first-line exam. We aimed to evaluate its diagnostic performance for the investigation of unselected causes of neonatal respiratory distress in daily practice. We conducted a descriptive, prospective, and single-center diagnostic accuracy study in a tertiary hospital, including term and preterm newborns who needed a CXR because of respiratory conditions occurring at birth or during the first 24h of life. TUS was compared to the reference diagnosis, which was the association between the CXR results, the clinical initial context, and the patient's outcome. Fifty-two newborns were included and 104 hemi-thorax ultrasounds were analyzed. Sensitivity, specificity, positive and negative predictive values (PPV, NPV), diagnosis accuracy, as well as the positive and negative likelihood ratio of TUSs were 100% for respiratory distress syndrome (RDS), transient tachypnea of newborn (TTN), pneumomediastinum, meconium aspiration syndrome, and absence of pulmonary disease. TUS also showed 100% sensitivity and NPV for pneumothorax, but specificity was 97% and PPV was 50%. Kappa concordance between TUS and either CXR alone or the radiological/clinical gold standard was 0.79 and 0.95, respectively. CONCLUSION: TUS at the newborn's bedside is efficient for investigating the main neonatal respiratory diseases, especially for the confirmation of RDS or TTN and for the exclusion of differential diagnosis or complications.


Assuntos
Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico por imagem , Feminino , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos , Radiografia Torácica , Reprodutibilidade dos Testes , Ultrassonografia
3.
Transplant Proc ; 51(1): 171-178, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30655149

RESUMO

BACKGROUND: Cirrhosis for biliary atresia (BA) is associated with risk of gastrointestinal bleeding (GB) from gastroesophageal varices due to portal hypertension. Primary prophylaxis of GB is controversial in children who are candidates for liver transplantation (LT). The aim of the study was to define the management of gastroesophageal varices and to identify the benefit of primary prophylaxis for GB in BA children waiting for LT. METHODS: A retrospective single-center study including all BA children listed for LT in 2008-2016. Clinical, endoscopical, and biochemical data were analyzed. RESULTS: Of 82 children, 50 (61%) did not receive primary prophylaxis and did not present any episode of bleeding, 16 (19.5%) underwent primary prophylaxis, and 16 (19.5%) presented spontaneous GB and received secondary prophylaxis. Children without primary prophylaxis and GB were younger than patients with primary prophylaxis and those with GB (7.7 years [range, 4.1-37.9 years] vs 11.2 years [range, 5.1-43 years]; P = .03 vs 10.7 years [range, 6.9-39.9 years], respectively; P = .004). Seventy-five percent of GB occurred in children older than 8 months. Fifteen (93.8%) children with GB presented esophageal varices (grade III = 10 [62.5%]) and 10 (62.5%) required endoscopic treatments, consisting mainly of sclerotherapy. Median time to LT was similar for children with or without bleeding (2 months [range, 0-17.7 months] vs 2.2 months [0-17.9 months], respectively; P = .89). After 45.5 months (range, 13.7-105.5 months) of follow-up, the overall patient survival was 97.6%. At the intention-to-treat analysis, the survival rate was 100% for patients without bleeding episode and 87.5% for children with GB (P = .16). CONCLUSIONS: Despite the risk of GB being not clinically predictable in children with BA waiting for LT, our experience suggests that primary prophylaxis of GB might be unnecessary in children younger than 6 months, while it should be considered in older children. Thus, the occurrence of GB does not delay the timing of transplantation.


Assuntos
Atresia Biliar/complicações , Hemorragia Gastrointestinal/prevenção & controle , Transplante de Fígado , Adolescente , Adulto , Criança , Pré-Escolar , Varizes Esofágicas e Gástricas/complicações , Feminino , Hemorragia Gastrointestinal/epidemiologia , Hemorragia Gastrointestinal/etiologia , Humanos , Hipertensão Portal/complicações , Masculino , Prevenção Primária , Estudos Retrospectivos , Adulto Jovem
4.
Environ Sci Technol ; 52(20): 11573-11582, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30222337

RESUMO

We used natural mercury (Hg) stable isotopes to investigate the Hg cycle in a rainforest soil catena (French Guiana) partially gold-mined during the early 1950s. Litterfall showed homogeneous Δ199Hg values [-0.18 ± 0.05‰, i.e., a modern gaseous elemental Hg (GEM) isotopic signature]. After litter decomposition, Hg bound to organic matter (OM) is mixed with Hg from pristine (-0.55 ± 0.22‰) or gold-mined (-0.09 ± 0.16‰) mineral materials. Negative Δ199Hg values in deep pristine mineral horizons (-0.60 ± 0.16‰) suggest the transfer of Hg bound to dissolved OM depleted in odd isotopes due to mass-independent fractionation during Hg abiotic reduction. Perennial palm tree leaves collected above gold-mined and pristine soil recorded contrasting Δ199Hg signatures likely resulting from GEM re-emission processes from soils and leaf surfaces. Upslope, soil δ202Hg signatures showed a negative shift (ε ∼ -1‰) with depth attributed to mass-dependent fractionation during Hg sorption and complexation onto iron oxides and dissolved OM. Downslope, higher δ202Hg values in soils resulted from hydromorphy [lower humification, greater Hg(II) reduction, etc.]. The unique Hg isotopic signatures of Amazonian soils probably result in multistep fractionation processes during pedogenesis (millions of years) and in a potentially different Hg isotopic signature of preanthropogenic background GEM.


Assuntos
Mercúrio , Solo , Monitoramento Ambiental , Florestas , Guiana Francesa , Ouro , Isótopos de Mercúrio , Mineração
5.
J Appl Microbiol ; 125(3): 907-916, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29791788

RESUMO

AIMS: The objective of our study was to compare the microbiota diversity between two different age groups of Western European women. METHODS AND RESULTS: Skin-swab samples were collected directly on the forehead of 34 healthy Western European women: 17 younger (21-31 years old) and 17 older individuals (54-69 years old). Bacterial communities were evaluated using the 16S rRNA gene sequencing. Data revealed a higher alpha diversity on the skin of older individuals compared with younger ones. Overall microbiota structure was different between the two age groups, as demonstrated by beta diversity analysis, which also highlighted a high interpersonal variation within older individuals. Furthermore, taxonomic composition analysis showed both an increase in Proteobacteria and a decrease in Actinobacteria on the older skin. At the genus level, older skin exhibited a significant increase in Corynebacterium and a decrease in Propionibacterium relative abundance. CONCLUSIONS: Our study revealed a shift in the distribution of skin microbiota during chronological aging in Western European women. SIGNIFICANCE AND IMPACT OF STUDY: Altogether these results could become the basis to develop new approaches aiming to rebalance the skin microbiota, which is modified during the aging process.


Assuntos
Envelhecimento/fisiologia , Microbiota/genética , Pele/microbiologia , Adulto , Idoso , Bactérias/classificação , Bactérias/genética , Europa (Continente) , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem
6.
Transplant Proc ; 50(1): 175-183, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29407305

RESUMO

AIM: We designed a retrospective case-control study to determine the efficacy and feasibility of everolimus (EVR) combined with low-dose tacrolimus (Tac) ab initio versus standard-dose Tac after liver transplantation (LT). METHODS: Seventy-one adult LT patients, receiving EVR and low-dose Tac without corticosteroids or induction therapy from postoperative day 1 (EVR group) were compared with a well-matched control group of 61 recipients treated with standard-dose Tac in association with antimetabolite. RESULTS: Baseline characteristics for the two groups were comparable. The overall patient and graft survival rates were similar (P = .908). Liver function was stable during the follow-up. In the EVR group, biopsy-proven acute rejection occurred in two cases (2.8%), whereas chronic rejection occurred in one (1.4%). The EVR group experienced a better renal function already after 2 weeks (estimated glomerular filtration rate: 89.85 [36.46 to 115.3] mL/min/1.73 m2 vs. 68.77 [16.11 to 115.42] mL/min/1.73 m2; P = .013), which was also observed after a median time of 27 months (range, 0 to 82 months) from LT (estimated glomerular filtration rate: 80 [45 to 118.3] mL/min/1.73 m2 vs. 70.9 [45 to 88.4] mL/min/1.73 m2; P = .04). After a median time of 27 months, the EVR group showed lower incidence of arterial hypertension and insulin-dependent diabetes mellitus. CONCLUSION: Ab initio EVR-based immunosuppression could be a valid option immediately after surgery in recipients at high-risk for post-LT renal impairment.


Assuntos
Everolimo/administração & dosagem , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Transplante de Fígado/métodos , Tacrolimo/administração & dosagem , Adulto , Idoso , Biópsia , Inibidores de Calcineurina/administração & dosagem , Estudos de Casos e Controles , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/etiologia , Quimioterapia Combinada , Estudos de Viabilidade , Feminino , Taxa de Filtração Glomerular , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/efeitos dos fármacos , Humanos , Hipertensão/epidemiologia , Hipertensão/etiologia , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de Tempo
7.
Pediatr Transplant ; 22(1)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29171131

RESUMO

ARF after pediatric liver transplantation accounts for high rate of morbidity and mortality associated with this procedure. The role of CPAP in postoperative period is still unknown. The aim of the study was to describe current practice and risk factors associated with the application of helmet CPAP. In this retrospective observational cohort study, 119 recipients were divided into two groups based on indication to CPAP after extubation. Perioperative variables were studied, and determinants of CPAP application were analyzed in a multivariate logistic model. Sixty patients (60/114) developed ARF and were included in the CPAP group. No differences were found between the two groups for primary disease, graft type, and blood product transfused. At multivariate analysis, weight <11 kg (OR = 2.9; 95% CI = 1.1-7.3; P = .026), PaO2 /FiO2 <380 before extubation (OR = 5.4; 95% CI = 2.1-13.6; P < .001), need of vasopressors (OR = 2.6; 95% CI = 1.1-6.4; P = .038), and positive fluid balance >148 mL/kg (OR = 4.0; 95% CI = 1.6-10.1; P = .004) were the main determinants of CPAP application. In the CPAP group, five patients (8.4%) needed reintubation. Pediatric liver recipients with lower weight, higher need of inotropes/vasopressors, higher positive fluid balance after surgery, and lower PaO2 /FiO2 before extubation were at higher odds of developing ARF needing CPAP application.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Transplante de Fígado , Complicações Pós-Operatórias/terapia , Insuficiência Respiratória/terapia , Doença Aguda , Adolescente , Criança , Pré-Escolar , Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Pressão Positiva Contínua nas Vias Aéreas/métodos , Feminino , Humanos , Lactente , Modelos Logísticos , Masculino , Análise Multivariada , Complicações Pós-Operatórias/etiologia , Insuficiência Respiratória/etiologia , Estudos Retrospectivos , Fatores de Risco
9.
Med Sante Trop ; 26(4): 345-350, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28073713

RESUMO

Through its Priority Solidarity Fund, France set up a partnership with four United Nations agencies, WHO, UNICEF, UNFPA, and UN WOMEN for the years 2011-2015 with an annual budget of 19 M €. An additional sixth year supplementary is underway. The program was developed through a common framework of actions coordinated and harmonized at the level of the target countries: integrated management of childhood diseases, mother-child nutrition, prenatal, perinatal, and postpartum follow-up, sexual and reproductive health, and adolescent health. The contribution of WHO was based on its normative role; UNICEF offered its operational capacity in the field, and UNFPA its focus on reproductive health, while UN WOMEN dealt with gender questions. The countries targeted specifically were: Benin, Burkina Faso, Côte d'Ivoire, Guinea, Haiti, Mali, Nigeria, Central Africa Republic, Democratic Republic of the Congo, Senegal, Chad, and Togo.


Assuntos
Administração Financeira , Saúde Global , Objetivos Organizacionais , Nações Unidas/economia , França , Humanos
10.
Med Sante Trop ; 26(4): 375-376, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28073725

RESUMO

Substantial progress has been accomplished in reducing maternal, neonatal, and infant mortality, but the work to meet the Millennium Development Goals, boosted by numerous initiatives, including Muskoka, is far from finished. Since 2016, the Sustainable Development Goals, as well as the International Strategy for Women's, Children's, and Adolescent Health 2016 - 2030, have provided to the countries and development partners a consistent framework for action enlarged to all of the dimensions of human development, while keeping women, children, and adolescents at its heart. In this context, the Muskoka program, after an initial 5-year cycle, will continue in 2017.


Assuntos
Administração Financeira , Nações Unidas , África , Desenvolvimento Econômico , França , Humanos , Lactente , Mortalidade Infantil , Mortalidade Materna
11.
Pediatr Transplant ; 19(5): 517-26, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26059061

RESUMO

UNLABELLED: Controversy remains about the best line of division for liver splitting, through Segment IV or through the umbilical fissure. Both techniques are currently used, with the choice varying between surgical teams in the absence of an evidence-based choice. We conducted a single-center retrospective analysis of 47 left split liver grafts that were procured with two different division techniques: "classical" (N = 28, Group A) or through the umbilical fissure and plate (N = 19, Group B). The allocation of recipients to each group was at random; a single transplant team performed all transplantations. Demographics, characteristics, technical aspects, and outcomes were similar in both groups. The grafts in Group A, prepared with the classical technique, were procured more often with a single BD orifice compared with the grafts in Group B; however, this was not associated with a higher incidence of biliary problems in this series of transplants (96% actual graft survival rate [median ± s.d. FOLLOW-UP: 26 ± 20 months]). Both techniques provide good quality split grafts and an excellent outcome; surgical expertise with a given technique is more relevant than the technique itself. The classical technique, however, seems to be more flexible in various ways, and surgeons may find it to be preferable.


Assuntos
Hepatectomia/métodos , Transplante de Fígado/métodos , Fígado/cirurgia , Procedimentos Cirúrgicos Operatórios , Adulto , Criança , Pré-Escolar , Bases de Dados Factuais , Sobrevivência de Enxerto , Humanos , Lactente , Doadores Vivos , Pessoa de Meia-Idade , Estudos Retrospectivos , Obtenção de Tecidos e Órgãos , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Umbigo/cirurgia
12.
Pediatr Transplant ; 19(4): 358-65, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25879299

RESUMO

Biliary complications remain a major challenge for long-term success after LT, as it is, as a rule, the most common technical - early and late - complication that occurs, and because these complications contribute to a significant number of late graft losses and retransplantations. In the pediatric age group, both biliary atresia, as the patient's condition, and the use of a left liver graft, obtained by a liver division technique, make it necessary for the use of a Roux-en-Y jejunal loop for the biliary reconstruction in the majority of cases. A slight modification of the technique is presented, consisting of a straight positioning along the cut surface (rather than the conventional position that results in a harpoon shape). A favorable outcome in terms of a technical complication and graft survival was observed. This way of doing this is an interesting variation and adds to the surgical armamentarium.


Assuntos
Anastomose em-Y de Roux/métodos , Jejunostomia/métodos , Transplante de Fígado/métodos , Anastomose Cirúrgica , Ductos Biliares/cirurgia , Procedimentos Cirúrgicos do Sistema Biliar/métodos , Criança , Pré-Escolar , Feminino , Sobrevivência de Enxerto , Humanos , Lactente , Fígado/cirurgia , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos
13.
Cytokine ; 66(2): 143-55, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24412476

RESUMO

As a result of the CD28 superagonist biotherapeutic monoclonal antibody (TGN 1412) "cytokine storm" incident, cytokine release assays (CRA) have become hazard identification and prospective risk assessment tools for screening novel biotherapeutics directed against targets having a potential risk for eliciting adverse pro-inflammatory clinical infusion reactions. Different laboratories may have different strategies, assay formats, and approaches to the reporting, interpretation, and use of data for either decision making or risk assessment. Additionally, many independent contract research organizations (CROs), academic and government laboratories are involved in some aspect of CRA work. As a result, while some pharmaceutical companies are providing CRA data as part of the regulatory submissions when necessary, technical and regulatory practices are still evolving to provide data predictive of cytokine release in humans and that are relevant to safety. This manuscript provides an overview of different approaches employed by the pharmaceutical industry and CROs, for the use and application of CRA based upon a survey and post survey follow up conducted by ILSI-Health and Environmental Sciences Institute (HESI) Immunotoxicology Committee CRA Working Group. Also discussed is ongoing research in the academic sector, the regulatory environment, current limitations of the assays, and future directions and recommendations for cytokine release assays.


Assuntos
Bioensaio/métodos , Citocinas/sangue , Anticorpos Monoclonais Humanizados , Antígenos CD28/imunologia , Citocinas/imunologia , Avaliação Pré-Clínica de Medicamentos , Humanos , Inflamação/sangue , Inflamação/imunologia , Insuficiência de Múltiplos Órgãos/imunologia
14.
Mol Psychiatry ; 19(5): 607-14, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23711979

RESUMO

Deep brain stimulation (DBS) in the subgenual cingulated gyrus (SCG) is a promising new technique that may provide sustained remission in resistant major depressive disorder (MDD). Initial studies reported a significant early improvement in patients, followed by a decline within the first month of treatment, an unexpected phenomenon attributed to potential placebo effects or a physiological response to probe insertion that remains poorly understood. Here we characterized the behavioural antidepressant-like effect of DBS in the rat medial prefrontal cortex, focusing on modifications to rodent SCG correlate (prelimbic and infralimbic (IL) cortex). In addition, we evaluated the early outcome of DBS in the SCG of eight patients with resistant MDD involved in a clinical trial. We found similar antidepressant-like effects in rats implanted with electrodes, irrespective of whether they received electrical brain stimulation or not. This effect was due to regional inflammation, as it was temporally correlated with an increase of glial-fibrillary-acidic-protein immunoreactivity, and it was blocked by anti-inflammatory drugs. Indeed, inflammatory mediators and neuronal p11 expression also changed. Furthermore, a retrospective study indicated that the early response of MDD patients subjected to DBS was poorer when they received anti-inflammatory drugs. Our study demonstrates that electrode implantation up to the IL cortex is sufficient to produce an antidepressant-like effect of a similar magnitude to that observed in rats receiving brain stimulation. Moreover, both preclinical and clinical findings suggest that the use of anti-inflammatory drugs after electrode implantation may attenuate the early anti-depressive response in patients who are subjected to DBS.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiopatologia , Estimulação Encefálica Profunda , Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Maior/terapia , Animais , Doença Crônica , Estimulação Encefálica Profunda/efeitos adversos , Modelos Animais de Doenças , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Giro do Cíngulo/efeitos dos fármacos , Giro do Cíngulo/fisiopatologia , Humanos , Masculino , Neuroimunomodulação/efeitos dos fármacos , Neuroimunomodulação/fisiologia , Ratos Wistar , Estudos Retrospectivos , Estresse Psicológico , Resultado do Tratamento
15.
Pediatr Obes ; 9(5): e99-e102, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24302697

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) may develop from non-alcoholic fatty liver disease (NAFLD) either in the presence or in the absence of established cirrhosis. Non-cirrhotic patients with NAFLD-related HCC are usually adult, male and obese. However, this association has not been reported yet in younger age groups. Objectives In the present study, the clinical case of a 7-yaer-old obese boy with steatosis and HCC is presented. METHODS: A 7-year-old boy, with no evidence of chronic liver disease, was admitted for assessment of a liver mass. Preliminary assessment was suggestive of a combined and severe liver steatosis together with a malignant disease. RESULTS: A biopsy confirmed the suspected diagnosis of HCC; interestingly, the non-neoplastic liver was surrounded and characterized by the presence of steatosis and ballooning, and being absent of lobular inflammation and fibrosis. Chemotherapy and diet changes were conducted successfully with ultrasound characteristics suggesting improvements on both aspects: conventional liver mass resection could take place. CONCLUSIONS: This case report suggests that HCC might develop in paediatric age patients with obesity-related NAFLD, even in the absence of fibrosis.


Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Fígado/patologia , Obesidade Infantil/complicações , Redução de Peso , Biópsia , Índice de Massa Corporal , Carcinoma Hepatocelular/terapia , Criança , Comorbidade , Humanos , Neoplasias Hepáticas/terapia , Masculino , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/terapia , Obesidade Infantil/patologia , Obesidade Infantil/terapia , Resultado do Tratamento
16.
Artigo em Inglês | MEDLINE | ID: mdl-24229148

RESUMO

We study by simulation and theory how the addition of insulating spherical particles affects the conductivity of fluids of conducting rods, modeled by spherocylinders. The electrical connections are implemented as tunneling processes, leading to a more detailed and realistic description than a discontinuous percolation approach. We find that the spheres enhance the tunneling conductivity for a given concentration of rods and that the enhancement increases with rod concentration into the regime where the conducting network is well established. By reformulating the network of rods using a critical path analysis, we quantify the effect of depletion-induced attraction between the rods due to the spheres. Furthermore, we show that our conductivity data are quantitatively reproduced by an effective-medium approximation, which explicitly relates the system tunneling conductance to the structure of the rod-sphere fluid.

17.
Arch Pediatr ; 20(6): 640-5, 2013 Jun.
Artigo em Francês | MEDLINE | ID: mdl-23639836

RESUMO

Continuous urinary leakage, despite normal deliberate voiding, must suggest the diagnosis of ectopic ureter, more specifically in girls. Ectopic ureter is usually associated with duplex kidney and complete ureteral duplication. The strategy of investigations has changed over the past few years, due to MRI development in the analysis of urinary tract malformations. We report the case of a 4-year-old girl who presented with these symptoms and had a suspicion of left duplex kidney on the prenatal ultrasonography (US). Two US examinations during the first months of life were compatible with a left duplex kidney without any complication. Another US at the age of 4 years was reported as normal. We completed the investigation with MR urography, which revealed a left duplex kidney with a poorly functioning dysplastic upper pole, and the orifice of the ureter of this upper pole inserting in the vagina. The surgical treatment, realized by celioscopy, was partial nephrectomy of the upper pole, removing most of the ectopic ureter. US is the first exam to investigate urinary tract malformations. However, duplex kidney with small dysplastic pole and ectopic insertion of a nondilated ureter may be difficult to see, and a normal US should never end the investigations. Intravenous urography and renal scintigraphy used to be the reference complementary exams, but are now replaced by MR urography. Without using ionizing radiation, MR urography can visualize duplex kidney and ectopic ureteral insertion with high resolution, and evaluates renal function of each kidney and each pole. These morphological and functional data are essential to determine the surgical treatment.


Assuntos
Diagnóstico por Imagem/métodos , Incontinência Urinária/diagnóstico , Pré-Escolar , Meios de Contraste , Feminino , Seguimentos , Humanos , Aumento da Imagem/métodos , Rim/anormalidades , Rim/diagnóstico por imagem , Laparoscopia/métodos , Imageamento por Ressonância Magnética/métodos , Nefrectomia/métodos , Ultrassonografia , Ureter/anormalidades , Ureter/diagnóstico por imagem , Vagina/anormalidades
18.
J Chem Phys ; 136(16): 164903, 2012 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-22559502

RESUMO

In conductor-insulator nanocomposites in which conducting fillers are dispersed in an insulating matrix, the electrical connectedness is established by inter-particle tunneling or hopping processes. These systems are intrinsically non-percolative and a coherent description of the functional dependence of the conductivity σ on the filler properties, and in particular of the conductor-insulator transition, requires going beyond the usual continuum percolation approach by relaxing the constraint of a fixed connectivity distance. In this article, we consider dispersions of conducting spherical particles which are connected to all others by tunneling conductances and which are subjected to an effective attractive square-well potential. We show that the conductor-insulator transition at low contents φ of the conducting fillers does not determine the behavior of σ at larger concentrations, in striking contrast to what is predicted by percolation theory. In particular, we find that at low φ the conductivity is governed almost entirely by the stickiness of the attraction, while at larger φ values σ depends mainly on the depth of the potential well. As a consequence, by varying the range and depth of the potential while keeping the stickiness fixed, composites with similar conductor-insulator transitions may display conductivity variations of several orders of magnitude at intermediate and large φ values. By using a recently developed effective medium theory and the critical path approximation, we explain this behavior in terms of dominant tunneling processes which involve inter-particle distances spanning different regions of the square-well fluid structure as φ is varied. Our predictions could be tested in experiments by changing the potential profile with different depletants in polymer nanocomposites.

19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(1 Pt 1): 011137, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22400542

RESUMO

We consider the problem of electron transport in segregated conductor-insulator composites in which the conducting particles are connected to all others via tunneling conductances, thus forming a global tunneling-connected resistor network. Segregation is induced by the presence of large insulating particles, which forbid the much smaller conducting fillers from occupying uniformly the three-dimensional volume of the composite. By considering both colloidal-like and granular-like dispersions of the conducting phase, modeled respectively by dispersions in the continuum and in the lattice, we evaluate by Monte Carlo simulations the effect of segregation on the composite conductivity σ, and show that an effective-medium theory applied to the tunneling network reproduces accurately the Monte Carlo results. The theory clarifies that the main effect of segregation in the continuum is that of reducing the mean interparticle distances, leading to a strong enhancement of the conductivity. In the lattice-segregation case the conductivity enhancement is instead given by the lowering of the percolation thresholds for first and beyond-first nearest neighbors. Our results generalize to segregated composites the tunneling-based description of both the percolation and hopping regimes introduced previously for homogeneous disordered systems.


Assuntos
Manufaturas , Modelos Estatísticos , Modelos Teóricos , Semicondutores , Simulação por Computador , Condutividade Elétrica
20.
Pediatr Transplant ; 16(7): E265-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22093884

RESUMO

FNH is a rare and benign tumor of the liver. It is not a conventional indication for liver transplantation, and no transplant for FNH in a child has been reported to date. Multifocal FNH growing in adolescent age to a widespread tumor invading the whole liver and associated with severe refractory pruritus was an unusual indication for transplantation in a 13-yr-old girl. The operation and the follow-up were uneventful, allowing full recovery and disappearance of pruritus.


Assuntos
Hiperplasia Nodular Focal do Fígado/complicações , Hiperplasia Nodular Focal do Fígado/terapia , Transplante de Fígado/métodos , Prurido/terapia , Adolescente , Criança , Feminino , Humanos , Fígado/anormalidades , Fígado/patologia , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
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