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1.
Environ Sci Technol ; 58(14): 6381-6390, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38547454

RESUMO

The objective of this study was to determine if U sediment concentrations in a U-contaminated wetland located within the Savannah River Site, South Carolina, were greater in the rhizosphere than in the nonrhizosphere. U concentrations were as much as 1100% greater in the rhizosphere than in the nonrhizosphere fractions; however and importantly, not all paired samples followed this trend. Iron (but not C, N, or S) concentrations were significantly enriched in the rhizosphere. XAS analyses showed that in both sediment fractions, U existed as UO22+ coordinated with iron(III)-oxides and organic matter. A key difference between the two sediment fractions was that a larger proportion of U was adsorbed to Fe(III)-oxides, not organic matter, in the rhizosphere, where significantly greater total Fe concentrations and greater proportions of ferrihydrite and goethite existed. Based on 16S rRNA analyses, most bacterial sequences in both paired samples were heterotrophs, and population differences were consistent with the generally more oxidizing conditions in the rhizosphere. Finally, U was very strongly bound to the whole (unfractionated) sediments, with an average desorption Kd value (Usediment/Uaqueous) of 3972 ± 1370 (mg-U/kg)/(mg-U/L). Together, these results indicate that the rhizosphere can greatly enrich U especially in wetland areas, where roots promote the formation of reactive Fe(III)-oxides.


Assuntos
Compostos Férricos , Urânio , Áreas Alagadas , Rizosfera , RNA Ribossômico 16S , Ferro , Óxidos/análise , Oxirredução , Sedimentos Geológicos/microbiologia
2.
Environ Sci Technol ; 58(33): 14687-14697, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39115966

RESUMO

As global change processes modify the extent and functions of terrestrial-aquatic interfaces, the variability of critical and dynamic transitional zones between wetlands and uplands increases. However, it is still unclear how fluctuating water levels at these dynamic boundaries alter groundwater biogeochemical cycling. Here, we used high-temporal resolution data along gradients from wetlands to uplands and during fluctuating water levels at freshwater coastal areas to capture spatiotemporal patterns of groundwater redox potential (Eh). We observed that topography influences groundwater Eh that is higher in uplands than in wetlands; however, the high variability within TAI zones challenged the establishment of distinct redox zonation. Declining water levels generally decreased Eh, but most locations exhibited significant Eh variability, which is associated with rare instances of short-term water level fluctuations, introducing oxygen. The Eh-oxygen relationship showed distinct hysteresis patterns, reflecting redox poising capacity at higher Eh, maintaining more oxidizing states longer than the dissolved oxygen presence. Surprisingly, we observed more frequent oxidizing states in transitional areas and wetlands than in uplands. We infer that occasional oxygen entering specific wetland-upland boundaries acts as critical biogeochemical control points. High-resolution data can capture such rare yet significant biogeochemical instances, supporting redox-informed models and advancing the predictability of climate change feedback.


Assuntos
Água Subterrânea , Oxirredução , Áreas Alagadas , Água Subterrânea/química
3.
J Pediatr Gastroenterol Nutr ; 79(3): 610-621, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39020449

RESUMO

OBJECTIVE: Genetic and environmental factors influence pathogenesis and rising incidence of paediatric inflammatory bowel disease (PIBD). The aim was to meta-analyse evidence of diet and environmental factors in PIBD. METHODS: A systematic search was conducted to identify diet and environmental factors with comparable risk outcome measures and had been reported in two or more PIBD studies for inclusion in meta-analyses. Those with ≥2 PIBD risk estimates were combined to provide pooled risk estimates. RESULTS: Of 4763 studies identified, 36 studies were included. PIBD was associated with higher risk with exposure to ≥/=4 antibiotic courses (includes prescriptions/purchases/courses), passive smoking, not being breastfed, sugary drink intake, being a non-Caucasian child living in a high-income country and infection history (odds ratio [OR] range: 2-3.8). Paediatric Crohn's disease (CD) was associated with higher risk with exposure to antibiotics during early childhood, ≥/=4 antibiotic courses, high socioeconomic status (SES), maternal smoking, history of atopic conditions and infection history (OR range: 1.6-4.4). A history of infection was also associated with higher risk of paediatric ulcerative colitis (UC) (OR: 3.73). Having a higher number of siblings (≥2) was associated with lower risk of paediatric CD (OR: 0.6) and paediatric UC (OR: 0.7). Pet exposure was associated with lower risk of paediatric UC (OR: 0.5). CONCLUSION: Several factors associated with PIBD risk were identified that could potentially be used to develop a disease screening tool. Future research is needed to address risk reduction in PIBD.


Assuntos
Antibacterianos , Doenças Inflamatórias Intestinais , Classe Social , Bebidas Adoçadas com Açúcar , Poluição por Fumaça de Tabaco , Criança , Humanos , Antibacterianos/efeitos adversos , Colite Ulcerativa/etiologia , Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Doença de Crohn/etiologia , Doenças Inflamatórias Intestinais/etiologia , Doenças Inflamatórias Intestinais/epidemiologia , Fatores de Risco , Bebidas Adoçadas com Açúcar/efeitos adversos , Poluição por Fumaça de Tabaco/efeitos adversos
4.
J Environ Manage ; 368: 122127, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39128342

RESUMO

Construction and demolition wastes (CDWs) have become a significant environmental concern due to urbanization. CDWs in landfill sites can generate high-pH leachate and various constituents (e.g., acetate and sulfate) following the dissolution of cement material, which may affect subsurface biogeochemical properties. However, the impact of CDW leachate on microbial reactions and community compositions in subsurface environments remains unclear. Therefore, we created columns composed of layers of concrete debris containing-soil (CDS) and underlying CDW-free soil, and fed them artificial groundwater with or without acetate and/or sulfate. In all columns, the initial pH 5.6 of the underlying soil layer rapidly increased to 10.8 (without acetate and sulfate), 10.1 (with sulfate), 10.1 (with acetate), and 8.3 (with acetate and sulfate) within 35 days. Alkaliphilic or alkaline-resistant microbes including Hydrogenophaga, Silanimonas, Algoriphagus, and/or Dethiobacter were dominant throughout the incubation in all columns, and their relative abundance was highest in the column without acetate and sulfate (50.7-86.6%). Fe(III) and sulfate reduction did not occur in the underlying soil layer without acetate. However, in the column with acetate alone, pH was decreased to 9.9 after day 85 and Fe(II) was produced with an increase in the relative abundance of Fe(III)-reducing bacteria up to 9.1%, followed by an increase in the methanogenic archaea Methanosarcina, suggestive of methanogenesis. In the column with both acetate and sulfate, Fe(III) and sulfate reduction occurred along with an increase in both Fe(III)- and sulfate-reducing bacteria (19.1 and 17.7%, respectively), while Methanosarcina appeared later. The results demonstrate that microbial Fe(III)- and sulfate-reduction and acetoclastic methanogenesis can occur even in soils with highly alkaline pH resulting from the dissolution of concrete debris.


Assuntos
Microbiologia do Solo , Solo , Concentração de Íons de Hidrogênio , Solo/química , Instalações de Eliminação de Resíduos , Sulfatos/metabolismo , Anaerobiose , Bactérias/metabolismo , Água Subterrânea/química , Água Subterrânea/microbiologia
5.
Environ Sci Technol ; 56(17): 12702-12712, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35980135

RESUMO

Uranium mining and nuclear fuel production have led to significant U contamination. Past studies have focused on the bioreduction of soluble U(VI) to insoluble U(IV) as a remediation method. However, U(IV) is susceptible to reoxidation and remobilization when conditions change. Here, we demonstrate that a combination of adsorption and bioreduction of U(VI) in the presence of an organic ligand (siderophore desferrioxamine B, DFOB) and the Fe-rich clay mineral nontronite partially alleviated this problem. DFOB greatly facilitated U(VI) adsorption into the interlayer of nontronite as a stable U(VI)-DFOB complex. This complex was likely reduced by bioreduction intermediates such as the Fe(II)-DFOB complex and/or through electron transfer within a ternary Fe(II)-DFOB-U(VI) complex. Bioreduction with DFOB alone resulted in a mobile aqueous U(IV)-DFOB complex, but in the presence of both DFOB and nontronite U(IV) was sequestered into a solid. These results provide novel insights into the mechanisms of U(VI) bioreduction and the stability of U and have important implications for understanding U biogeochemistry in the environment and for developing a sustainable U remediation approach.


Assuntos
Sideróforos , Urânio , Adsorção , Argila , Compostos Férricos , Compostos Ferrosos , Ferro , Minerais , Oxirredução
6.
Environ Sci Technol ; 56(22): 16428-16440, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36301735

RESUMO

Increasing CO2 emission has resulted in pressing climate and environmental issues. While abiotic and biotic processes mediating the fate of CO2 have been studied separately, their interactions and combined effects have been poorly understood. To explore this knowledge gap, an iron-reducing organism, Orenia metallireducens, was cultured under 18 conditions that systematically varied in headspace CO2 concentrations, ferric oxide loading, and dolomite (CaMg(CO3)2) availability. The results showed that abiotic and biotic processes interactively mediate CO2 acidification and sequestration through "chain reactions", with pH being the dominant variable. Specifically, dolomite alleviated CO2 stress on microbial activity, possibly via pH control that transforms the inhibitory CO2 to the more benign bicarbonate species. The microbial iron reduction further impacted pH via the competition between proton (H+) consumption during iron reduction and H+ generation from oxidization of the organic substrate. Under Fe(III)-rich conditions, microbial iron reduction increased pH, driving dissolved CO2 to form bicarbonate. Spectroscopic and microscopic analyses showed enhanced formation of siderite (FeCO3) under elevated CO2, supporting its incorporation into solids. The results of these CO2-microbe-mineral experiments provide insights into the synergistic abiotic and biotic processes that alleviate CO2 acidification and favor its sequestration, which can be instructive for practical applications (e.g., acidification remediation, CO2 sequestration, and modeling of carbon flux).


Assuntos
Compostos Férricos , Ferro , Compostos Férricos/química , Ferro/química , Dióxido de Carbono , Bicarbonatos , Carbonatos/química , Minerais , Oxirredução
7.
Environ Sci Technol ; 55(9): 5929-5938, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33822593

RESUMO

Reduction of U(VI) to U(IV) drastically reduces its solubility and has been proposed as a method for remediation of uranium contamination. However, much is still unknown about the kinetics, mechanisms, and products of U(VI) bioreduction in complex systems. In this study, U(VI) bioreduction experiments were conducted with Shewanella putrefaciens strain CN32 in the presence of clay minerals and two organic ligands: citrate and EDTA. In reactors with U and Fe(III)-clay minerals, the rate of U(VI) bioreduction was enhanced due to the presence of ligands, likely because soluble Fe3+- and Fe2+-ligand complexes served as electron shuttles. In the presence of citrate, bioreduced U(IV) formed a soluble U(IV)-citrate complex in experiments with either Fe-rich or Fe-poor clay mineral. In the presence of EDTA, U(IV) occurred as a soluble U(IV)-EDTA complex in Fe-poor montmorillonite experiments. However, U(IV) remained associated with the solid phase in Fe-rich nontronite experiments through the formation of a ternary U(IV)-EDTA-surface complex, as suggested by the EXAFS analysis. Our study indicates that organic ligands and Fe(III)-bearing clays can significantly affect the microbial reduction of U(VI) and the stability of the resulting U(IV) phase.


Assuntos
Compostos Férricos , Urânio , Argila , Ligantes , Minerais , Oxirredução
8.
Pediatr Transplant ; 25(8): e14092, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34313365

RESUMO

BACKGROUND: Pediatric retransplantation is an accepted practice for graft failure and complications in Australasia. As 15% of children require a third transplant, this is a growing cohort with limited data in the literature. METHODS: We review nine patients from the commencement of our transplantation program in 1986 up to 2020 assessing demographics, prognosis, and outcome measures. RESULTS: Third transplant patient survival was comparative to first and second transplant patient survival at 5 years. All deaths were within the post-operative period and secondary to sepsis. Operative times and transfusion volumes were increased at third transplant (1.8 and 4.5 times compared to first transplant, respectively). Learning difficulties and psychological disturbances were prevalent (83% and 66.6%, respectively). CONCLUSIONS: While recent mortality outcomes appear comparable to undergoing a second liver transplant, third transplant operations were more complex. Neurological impairment and psychological disturbance appear to be prevalent and need to be considered in pre-transplant counseling.


Assuntos
Transplante de Fígado/estatística & dados numéricos , Complicações Pós-Operatórias/cirurgia , Adolescente , Austrália , Criança , Pré-Escolar , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Lactente , Masculino , Prognóstico , Reoperação/estatística & dados numéricos
9.
J Environ Manage ; 292: 112756, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33984641

RESUMO

Urban subsurface environments are often different from undisturbed subsurface environments due to the impacts of human activities. For example, deterioration of underground infrastructure can introduce elevated levels of Ca, Fe, and heavy metals into subsurface soils and groundwater. Likewise, leakage from sewer systems can lead to contamination by organic C, N, S, and P. However, the impact of these organic and inorganic compounds on biogeochemical processes including microbial redox reactions, mineral transformations, and microbial community transitions in urban subsurface environments is poorly understood. Here we conducted a microcosm experiment with soil samples from an urban construction site to investigate the possible biotic and abiotic processes impacted when sulfate and acetate or lactate were introduced into an urban subsurface environment. In the top-layer soil (0-0.3 m) microcosms, which were highly alkaline (pH > 10), the major impact was on abiotic processes such as secondary mineral precipitation. In the mid-layer (2-3 m) soil microcosms, the rate of Fe(III)-reduction and the amount of Fe(II) produced were greatly impacted by the specific organic acid added, and sulfate-reduction was not observed until after Fe(III)-reduction was complete. Near the end of the incubation, some genera related to syntrophic acetate oxidation and methanogenesis were observed in the lactate-amended microcosms. In the bottom-layer (7-8 m) soil microcosms, the rate of Fe(III)-reduction and the amount of Fe(II) produced were affected by the concentration of amended sulfate. Sulfate-reduction was concurrent with Fe(III)-reduction, suggesting that Fe(II) production was likely due to abiotic reduction of Fe(III) by sulfide produced by microbial sulfate reduction. The slightly acidic initial pH (~5.8) of the mid-soil system was a major factor controlling sequential microbial Fe(III) and sulfate reduction versus parallel Fe(III) and sulfate reduction in the bottom soil system, which had a neutral initial pH (~7.2). 16S rRNA gene-based community analysis revealed a variety of indigenous microbial groups including alkaliphiles, dissimilatory iron and sulfate reducers, syntrophes, and methanogens tightly coupled with, and impacted by, these complex abiotic and biogeochemical processes occurring in urban subsurface environments.


Assuntos
Compostos Férricos , Solo , Humanos , Oxirredução , RNA Ribossômico 16S , Microbiologia do Solo , Sulfatos
10.
J Environ Manage ; 285: 112087, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33582476

RESUMO

The construction of an underground facility can dramatically change the quality, flow direction, and level of groundwater. It may also impact subsurface microbial composition and activity. Groundwater quality was monitored over eight years in two observational wells near an underground disposal facility on the east coast of South Korea. The results showed dramatic increases in dissolved ions such as O2, Na, Ca, Mg, and SO4 during facility construction. Seepage water samples downgradient from the silos and tunnels, and precipitates deposited along the seepage water flow path were collected to determine the impact inside the disposal facility. X-ray analysis (powder X-ray diffraction (pXRD) and X-ray absorption fine structure (XAFS)) were used to characterize the mineral precipitates. Microbial community composition was determined by 16S rRNA gene sequencing. The seepage water composition was of two types: Ca-Cl and Ca-Na-HCO3. The ratio of Cl and δ18O showed that the Ca-Cl type seepage water was influenced by groundwater mixed with seawater ranging from 2.7% to 15.1%. Various sulfate-reducing bacteria were identified in the Ca-Cl type seepage water, exhibiting relatively high sulfate content from seawater intrusion. Samples from the Ca-Na-HCO3 type seepage water had an extremely high pH (>10) and abundance of Hydrogenophaga. The precipitates observed along the flow path of the seepage water included calcite, ferrihydrite, green rust, and siderite, depending on seepage water chemistry and microbial activity. This study suggests that the construction of underground structures creates distinct, localized geochemical conditions (e.g., high alkalinity, high salinity, and oxic conditions), which may impact microbial communities. These biogeochemical changes may have undesirable large-scale impacts such as water pump clogging. An understanding of the process and long-term monitoring are essential to assess the safety of underground facilities.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Minerais , RNA Ribossômico 16S/genética , República da Coreia , Água do Mar , Água , Poluentes Químicos da Água/análise
11.
Environ Sci Technol ; 54(16): 10128-10140, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32693580

RESUMO

Microbial iron reduction is a ubiquitous biogeochemical process driven by diverse microorganisms in a variety of environments. However, it is often difficult to separate the biological from the geochemical controls on bioreduction of Fe(III) oxides. Here, we investigated the primary driving factor(s) that mediate secondary iron mineral formation over a broad range of environmental conditions using a single dissimilatory iron reducer, Orenia metallireducens strain Z6. A total of 17 distinct geochemical conditions were tested with differing pH (6.5-8.5), temperature (22-50 °C), salinity (2-20% NaCl), anions (phosphate and sulfate), electron shuttle (anthraquinone-2,6-disulfonate), and Fe(III) oxide mineralogy (ferrihydrite, lepidocrocite, goethite, hematite, and magnetite). The observed rates and extent of iron reduction differed significantly with kint between 0.186 and 1.702 mmol L-1 day-1 and Fe(II) production ranging from 6.3% to 83.7% of the initial Fe(III). Using X-ray absorption and scattering techniques (EXAFS and XRD), we identified and assessed the relationship between secondary minerals and the specific environmental conditions. It was inferred that the observed bifurcation of the mineralization pathways may be mediated by differing extents of Fe(II) sorption on the remaining Fe(III) minerals. These results expand our understanding of the controls on biomineralization during microbial iron reduction and aid the development of practical applications.


Assuntos
Compostos Férricos , Firmicutes , Biomineralização , Ferro , Minerais , Oxirredução
12.
Med J Aust ; 213(10): 464-470, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33015834

RESUMO

OBJECTIVE: To assess long term graft and patient survival after donor liver retransplantation in children in Australia and New Zealand during 1986-2017; to determine the factors that influence survival. DESIGN: Retrospective cohort analysis (registry data). SETTING, PARTICIPANTS: Australia and New Zealand Liver Transplant Registry data for all liver retransplantations in children (under 18 years of age), 1986-2017, in all four paediatric and six adult liver transplantation centres in the two countries. MAIN OUTCOME MEASURES: Graft and patient survival at one, 5, 10 and 15 years. RESULTS: 142 liver retransplantations were undertaken in children (59 during 1986-2000, 83 during 2001-2017). Kaplan-Meier survival analysis indicated that survival was significantly greater during 2001-2017 than 1986-2000 (P < 0.001). During 2001-2017, graft survival one year after retransplantation was 84%, at 5 years 75%, at 10 years 70%, and at 15 years 54%; patient survival was 89% at one year, 87% at 5 years, 87% at 10 years, and 71% at 15 years. Median time between transplantations was 0.2 years (IQR, 0.03-1.4 years) during 1986-2000, and 1.8 years (IQR, 0.1-6.8 years) during 2001-2017 (P = 0.002). The proportion of graft failures that involved split grafts was larger during 2001-2017 (35 of 83, 42%) than 1986-2000 (10 of 59, 17%). Graft type, cause of graft failure, and number of transplants did not influence survival following retransplantation. CONCLUSION: Survival for children following retransplantation is excellent. Graft survival is similar for split and whole grafts. Children on the liver waiting list requiring retransplantation should have the same access to donor grafts as children requiring a first transplant.


Assuntos
Transplante de Fígado/mortalidade , Reoperação , Adulto , Austrália/epidemiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Lactente , Estimativa de Kaplan-Meier , Transplante de Fígado/métodos , Masculino , Nova Zelândia/epidemiologia , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Doadores de Tecidos , Resultado do Tratamento , Listas de Espera
13.
J Paediatr Child Health ; 56(11): 1669-1673, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33197974

RESUMO

Paediatric gastroenterology in Australia has undergone remarkable changes over the more than six decades since Charlotte Anderson's pioneering work, and is now a well-established specialty in its own right. Australian paediatric gastroenterologists have made important contributions nationally and internationally.


Assuntos
Gastroenterologia , Austrália , Criança , Humanos
15.
Environ Sci Technol ; 52(8): 4601-4609, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29630355

RESUMO

Green rusts (GRs) are redox active FeII-FeIII minerals that form in the environment via various biotic and abiotic processes. Although both biogenic (BioGR) and abiotic (ChemGR) GRs have been shown to reduce UVI, the dynamics of the transformations and the speciation and stability of the resulting UIV phases are poorly understood. We used carbonate extraction and XAFS spectroscopy to investigate the products of UVI reduction by BioGR and ChemGR. The results show that both GRs can rapidly remove UVI from synthetic groundwater via reduction to UIV. The initial products in the ChemGR system are solids-associated UIV-carbonate complexes that gradually transform to nanocrystalline uraninite over time, leading to a decrease in the proportion of carbonate-extractable U from ∼95% to ∼10%. In contrast, solid-phase UIV atoms in the BioGR system remain relatively extractable, nonuraninite UIV species over the same reaction period. The presence of calcium and carbonate in groundwater significantly increase the extractability of UIV in the BioGR system. These data provide new insights into the transformations of U under anoxic conditions in groundwater that contains calcium and carbonate, and have major implications for predicting uranium stability within redox dynamic environments and designing approaches for the remediation of uranium-contaminated groundwater.


Assuntos
Compostos de Urânio , Urânio , Compostos Férricos , Oxirredução , Espectroscopia por Absorção de Raios X
16.
J Environ Manage ; 206: 938-948, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29220820

RESUMO

Subsurface biogeochemistry and contaminant dynamics during the remediation of diesel-contamination by in-situ soil flushing were investigated at a site located in a coastal region. An in-situ sampler containing diesel-contaminated soils separated into two size fractions (<0.063- and <2-mm) was utilized in two monitoring wells: DH1 (located close to the injection and extraction wells for in-situ soil flushing) and DH2 (located beyond sheet piles placed to block the transport of leaked diesel). Total petroleum hydrocarbon (TPH) concentrations and biogeochemical properties were monitored both in soil and groundwater for six months. A shift occurred in the groundwater type from Ca-HCO3 to Na-Cl due to seawater intrusion during intense pumping, while the concentrations of Ni, Cu, Co, V, Cr, and Se increased substantially following surfactant (TWEEN 80) injection. The in-situ sampler with fine particles was more sensitive to variations in conditions during the remedial soil flushing process. In both wells, soil TPH concentrations in the <0.063-mm fraction were much higher than those in the <2-mm fraction. Increases in soil TPH in DH1 were consistent with the expected outcomes following well pumping and surfactant injection used to enhance TPH extraction. However, the number of diesel-degrading microorganisms decreased after surfactant injection. 16S-rRNA gene-based analysis also showed that the community composition and diversity depended on both particle size and diesel contamination. The multidisciplinary approach to the contaminated site assessments showed that soil flushing with surfactant enhanced diesel extraction, but negatively impacted in-situ diesel biodegradation as well as groundwater quality. The results also suggest that the in-situ sampler can be an effective monitoring tool for subsurface biogeochemistry as well as contaminant dynamics.


Assuntos
Hidrocarbonetos , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Solo , Microbiologia do Solo
17.
J Pediatr Gastroenterol Nutr ; 64(6): 898-902, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-26960173

RESUMO

INTRODUCTION: Lower gastrointestinal endoscopy (LGIE)/colonoscopy is frequently performed for rectal bleeding, recurrent abdominal pain, and the diagnosis of inflammatory bowel disease (IBD). Although these are common indications, the causes of isolated rectal bleeding and recurrent abdominal pain in the otherwise well child have not been described. METHODS: A retrospective analysis of patients who had had an LGIE/colonoscopy from January 2001 to December 2010 was performed. The following data were collected: demographic data, indication, distance reached, macroscopic findings, microscopic findings, diagnosis, additional procedures, and complications. RESULTS: There were a total of 999 colonoscopies. The colonoscopy was normal in 390 of 999 (39%). The commonest indication for colonoscopy was a diagnosis of suspected IBD, 449 of 999 (45%). IBD was confirmed in 282 of 449 (63%), but colonoscopy was normal in 143 of 449 (32%) of suspected IBD. Colonoscopy was performed for rectal bleeding in 197 of 999 (20%) of whom 141 of 197 (72%) were normal. There were 46 (5%) colonoscopies performed for recurrent abdominal pain, which were all normal. Our completion rate to the cecum and beyond was 521 of 999 (52%). Our perforation rate during the 10 years was 0.2%. CONCLUSIONS: Colonoscopy is a safe procedure in pediatrics; however, 39% of colonoscopies in this series were normal. Many of these could have been avoided by eliminating colonoscopy in patients with recurrent abdominal pain in the absence of other clinical features, conservative management with laxatives for those with fresh blood per rectum typical of anal fissures, and fecal calprotectin screening before endoscopy in patients with suspected IBD.


Assuntos
Dor Abdominal/etiologia , Colonoscopia/estatística & dados numéricos , Hemorragia Gastrointestinal/etiologia , Doenças Inflamatórias Intestinais/diagnóstico por imagem , Padrões de Prática Médica/estatística & dados numéricos , Procedimentos Desnecessários/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Colo/diagnóstico por imagem , Feminino , Humanos , Lactente , Recém-Nascido , Doenças Inflamatórias Intestinais/complicações , Masculino , Auditoria Médica , New South Wales , Pediatria , Reto/diagnóstico por imagem , Recidiva , Estudos Retrospectivos
18.
Pediatr Transplant ; 21(4)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28332273

RESUMO

We aimed to assess the incidence of HAT over three eras following implementation of microvascular techniques and a customized anticoagulation protocol in a predominantly cadaveric split liver transplant program. We retrospectively reviewed pediatric liver transplants performed between April 1986 and 2016 and analyzed the incidence HAT over three eras. In E1, 1986-2008, each patient received a standard dose of 5 U/kg/h of heparin and coagulation profiles normalized passively. In E2, 2008-2012, microvascular techniques were introduced. In E3, 2012-2016, in addition, a customized anticoagulation protocol was introduced which included replacement of antithrombin 3, protein C and S, and early heparinization. A total of 317 liver transplants were completed during the study period, with a median age of 31.7 months. In E1, 22% of grafts were cadaveric in situ split grafts, while the second and third eras used split grafts in 59.0% and 64.9% of cases, respectively. HAT occurred in 9.5% in the first era, 11.5% (P=.661) in the second, and dropped to 1.8% in the third era (P=.043). A routine anticoagulation protocol has significantly reduced the incidence of HAT post-liver transplantation in children in a predominantly cadaveric in situ split liver transplant program.


Assuntos
Anticoagulantes/uso terapêutico , Artéria Hepática , Transplante de Fígado/métodos , Microcirurgia/métodos , Complicações Pós-Operatórias/prevenção & controle , Trombose/prevenção & controle , Procedimentos Cirúrgicos Vasculares/métodos , Criança , Pré-Escolar , Protocolos Clínicos , Terapia Combinada , Quimioterapia Combinada , Feminino , Artéria Hepática/cirurgia , Humanos , Incidência , Lactente , Masculino , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Trombose/epidemiologia , Trombose/etiologia , Resultado do Tratamento
19.
J Pediatr Gastroenterol Nutr ; 64(2): 203-209, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28107282

RESUMO

OBJECTIVES: Most infants with biliary atresia (BA) require liver transplantation (LT) after hepatoportoenterostomy (HPE), including those who initially clear jaundice. The aim of the present study was to identify clinical and routine laboratory factors in infants with BA post-HPE that predict native liver survival at 2 years. METHODS: A retrospective cohort study was conducted in 217 patients with BA undergoing HPE in Sydney, Australia and Toronto, Canada between January 1986 and July 2009. Univariate and multivariate logistic regression using backwards-stepwise elimination identified variables at 3 months after HPE most associated with 2-year native liver survival. RESULTS: Significant variables (P < 0.05) on univariate analysis included serum total bilirubin (TB) and albumin at 3 months post-HPE, bridging fibrosis or cirrhosis on initial liver biopsy, ascites of <3 months post-HPE, type 3 BA anatomy, age at HPE of >45 days, change in length z scores within 3 months of HPE, and center. On multivariate analysis, TB (P < 0.0001) and albumin (P = 0.02) at 3 months post-HPE, and center (P = 0.0003) were independently associated with native liver survival. Receiver operating characteristic analysis revealed an optimal cut-off value of TB <74 µmol/L (4.3 mg/dL; area under the receiver operating characteristic curve 0.8990) and serum albumin level >35 g/L (3.5 mg/dL; area under the receiver operating characteristic curve 0.7633) to predict 2-year native liver survival. TB and albumin levels 3 months post-HPE defined 3 groups (1: TB ≤74 µmol/L, albumin >35 g/L; 2: TB ≤74 µmol/L, albumin ≤35 g/L; 3: TB >74 µmol/L) with distinct short- and long-term native liver survival rates (log-rank P < 0.001). Length z scores 3 months post-HPE were poorer for group 2 than group 1 (-0.91 vs -0.30, P = 0.0217) with similar rates of coagulopathy. CONCLUSIONS: Serum TB and albumin levels 3 months post-HPE independently predicted native liver survival in BA when controlling for center. Serum albumin level <35 g/L in infants with BA who were no longer jaundiced at 3 months post-HPE was a poor prognostic indicator. Poorer linear growth and absence of significant coagulopathy suggest a role for early aggressive nutritional therapy in this group.


Assuntos
Atresia Biliar/cirurgia , Tomada de Decisão Clínica , Técnicas de Apoio para a Decisão , Doença Hepática Terminal/diagnóstico , Transplante de Fígado/estatística & dados numéricos , Portoenterostomia Hepática , Atresia Biliar/complicações , Pré-Escolar , Doença Hepática Terminal/etiologia , Doença Hepática Terminal/cirurgia , Feminino , Seguimentos , Indicadores Básicos de Saúde , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Masculino , Prognóstico , Curva ROC , Estudos Retrospectivos , Resultado do Tratamento
20.
J Pediatr Gastroenterol Nutr ; 64(4): 528-532, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27673709

RESUMO

OBJECTIVES: Research is lacking into the emotional effects on families of serious chronic illness in infants. We examined the effect of the diagnosis of serious liver disease in infants upon parent psychological symptoms and family functioning. We hypothesized that parent psychological symptoms, family functioning, and father engagement will predict infant emotional outcomes. METHODS: Parents of infants recently diagnosed with serious liver disease completed validated questionnaires about parent stress, family function, impact of the illness on the family, and father engagement. The measures were repeated after 1 year, with the addition of the Child Behavior Checklist (CBCL). RESULTS: Parents of 37 infants participated. Parent stress and family functioning scores were not elevated. Parent psychological symptoms, family function, and father engagement did not predict infant outcome. For mothers, infant diagnosis other than biliary atresia, number of outpatient visits, and impact of the illness on the family explained 32% of the variation in CBCL (P = 0.001). For fathers, socioeconomic status, infant diagnosis other than biliary atresia, whether the infant had had a transplant, and impact of the illness on the family explained 44% of the variation in CBCL (P < 0.001). CONCLUSIONS: Parents and families appear to be resilient in coping with serious infant illness. Infant diagnosis other than biliary atresia and parental perceptions of high impact of the illness on the family are indicators of negative emotional outcomes for infants with serious liver disease. Psychosocial interventions for infants with chronic illness should target reducing the impact of illness on the family.


Assuntos
Adaptação Psicológica , Relações Familiares/psicologia , Comportamento do Lactente/psicologia , Hepatopatias/psicologia , Transplante de Fígado/psicologia , Estresse Psicológico/etiologia , Atresia Biliar/diagnóstico , Atresia Biliar/psicologia , Atresia Biliar/cirurgia , Pré-Escolar , Doença Crônica , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Hepatopatias/diagnóstico , Hepatopatias/cirurgia , Masculino , Pais/psicologia , Resiliência Psicológica , Inquéritos e Questionários
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