RESUMO
Supramolecular metallogels combine the rheological properties of gels with the color, magnetism, and other properties of metal ions. Lanthanide ions such as Eu(III) can be valuable components of metallogels due to their fascinating luminescence. In this work, we combine Eu(III) and iminodiacetic acid (IDA) into luminescent hydrogels. We investigate the tailoring of the rheological properties of these gels by changes in their metal:ligand ratio. Further, we use the highly sensitive Eu(III) luminescence to obtain information about the chemical structure of the materials. In special, we take advantage of computational calculations to employ an indirect method for structural elucidation, in which the simulated luminescent properties of candidate structures are matched to the experimental data. With this strategy, we can propose molecular structures for different EuIDA gels. We also explore the usage of these gels for the loading of bioactive molecules such as OXA, observing that its aldose reductase activity remains present in the gel. We envision that the findings from this work could inspire the development of luminescent hydrogels with tunable rheology for applications such as 3D printing and imaging-guided drug delivery platforms. Finally, Eu(III) emission-based structural elucidation could be a powerful tool in the characterization of advanced materials.
Assuntos
Európio , Hidrogéis , Európio/química , Hidrogéis/química , Luminescência , Iminoácidos/química , Reologia , Substâncias Luminescentes/química , Ligantes , Géis/químicaRESUMO
A hepatobiliary iminodiacetic acid (HIDA) scan is frequently used in an attempt to exclude biliary atresia in infants who are cholestatic. We present 6 cases of confirmed biliary atresia in infants who had biliary patency reported on HIDA scan. We demonstrate that misinterpreted HIDA scans led to delayed diagnosis and surgical intervention for biliary atresia.
Assuntos
Atresia Biliar/diagnóstico por imagem , Atresia Biliar/fisiopatologia , Eliminação Hepatobiliar , Iminoácidos , Sistema Biliar/diagnóstico por imagem , Feminino , Humanos , Lactente , Recém-Nascido , Fígado/diagnóstico por imagem , Masculino , Cintilografia , Estudos RetrospectivosRESUMO
Iminodiacetic acid (IDA) is one of the chelating ligands most frequently employed in immobilized metal-ion affinity chromatography (IMAC) due to its ability to act as electron-pair donor, forming stable complexes with intermediate and borderline Lewis metal ions (electron acceptor). Thus, IDA can also be employed in ion exchange chromatography to purify positively charged proteins at neutral pH values. This study aimed to evaluate IDA as an ionogenic group (ion exchanger) immobilized on poly (ethylene vinyl alcohol) (PEVA) hollow fiber membranes for immunoglobulin G1 (IgG1) monoclonal antibody (MAb) purification. IDA-PEVA membranes showed considerable promise for MAb purification, since IgG1 was recovered in eluted fractions with traces of contaminants as confirmed by Western blotting and ELISA analysis. Quantification of IgG1 showed that a purity of 94.2% was reached in the elution step. Breakthrough curve and batch adsorption experiments showed that the MAb dynamic binding capacity (DBC) of 3.10 mg g-1 and the maximum adsorption capacity of 70 mg g-1 were of the same order of magnitude as those found in the literature. The results obtained showed that the IDA-PEVA hollow fiber membrane could be a powerful adsorbent for integrating large-scale processes for purification of MAb from cell culture supernatant.
Assuntos
Anticorpos Monoclonais/química , Cromatografia de Afinidade/métodos , Iminoácidos/química , Imunoglobulina G/química , Membranas Artificiais , Adsorção , Animais , Anticorpos Monoclonais/isolamento & purificação , Quelantes/química , Concentração de Íons de Hidrogênio , Imunoglobulina G/isolamento & purificação , Íons , Ligantes , Metais/química , CamundongosRESUMO
OBJECTIVE: To document the use of diagnostic testing in adolescents who ultimately were diagnosed with rumination syndrome, a functional gastrointestinal disorder. We examined the diagnostic yield of each test as well as the associated costs, and we determined if any demographic or illness-related variables impacted the magnitude of the work-up. STUDY DESIGN: A retrospective chart review was conducted for 68 patients with rumination syndrome admitted to our inpatient treatment program. The cost and findings of patients' diagnostic investigations were gathered, as well as demographic and illness-related variables to determine factors that may be related to evaluation size. RESULTS: The most commonly used tests in the evaluation of rumination syndrome included esophagogastroduodenoscopy, gastric emptying, antroduodenal manometry, upper gastrointestinal series, and abdominal ultrasound scan. Each patient underwent an average of 8.8 tests, with the average cost for each patient's diagnostic work-up being US $19 795. Few tests were found to be beneficial in the diagnosis of rumination syndrome, and few demographic or illness variables were found to be related to the overall extent of the investigation. CONCLUSIONS: Extensive testing for rumination syndrome in adolescents is common in clinical practice, and comes at a high financial cost with low yield, likely delaying diagnosis and treatment. Symptom-based criteria should be used to make the diagnosis of rumination syndrome.
Assuntos
Transtornos de Alimentação na Infância/diagnóstico , Transtornos de Alimentação na Infância/economia , Dor Abdominal/etiologia , Adolescente , Diagnóstico por Imagem/economia , Impedância Elétrica , Endoscopia Gastrointestinal/economia , Feminino , Esvaziamento Gástrico , Humanos , Iminoácidos/economia , Masculino , Manometria/economia , Ohio , Qualidade de Vida , Estudos Retrospectivos , Inquéritos e QuestionáriosAssuntos
Atresia Biliar/diagnóstico , Colestase Extra-Hepática/diagnóstico , Programas de Rastreamento/métodos , Pediatria/história , Atresia Biliar/história , Colestase Extra-Hepática/história , Diagnóstico Diferencial , História do Século XX , Humanos , Iminoácidos , Lactente , Programas de Rastreamento/história , Rosa Bengala/administração & dosagemAssuntos
Fístula Anastomótica/diagnóstico por imagem , Doenças dos Ductos Biliares/diagnóstico por imagem , Ductos Biliares/diagnóstico por imagem , Atresia Biliar/cirurgia , Meios de Contraste/administração & dosagem , Portoenterostomia Hepática/efeitos adversos , Fístula Anastomótica/etiologia , Fístula Anastomótica/metabolismo , Fístula Anastomótica/fisiopatologia , Doenças dos Ductos Biliares/etiologia , Doenças dos Ductos Biliares/metabolismo , Doenças dos Ductos Biliares/fisiopatologia , Ductos Biliares/metabolismo , Ductos Biliares/cirurgia , Sistema Biliar/diagnóstico por imagem , Sistema Biliar/metabolismo , Meios de Contraste/farmacocinética , Extravasamento de Materiais Terapêuticos e Diagnósticos/diagnóstico por imagem , Extravasamento de Materiais Terapêuticos e Diagnósticos/etiologia , Extravasamento de Materiais Terapêuticos e Diagnósticos/metabolismo , Feminino , Gadolínio DTPA/administração & dosagem , Gadolínio DTPA/farmacocinética , Humanos , Iminoácidos/administração & dosagem , Lactente , Ligamentos/diagnóstico por imagem , Ligamentos/metabolismo , Fígado/diagnóstico por imagem , Fígado/metabolismo , Imageamento por Ressonância Magnética , Distribuição TecidualRESUMO
Chilaiditi sign is the incidental radiologic finding of intestinal interposition between the liver and diaphragm, whereas Chilaiditi syndrome describes the presence of accompanying clinical symptoms including abdominal pain, constipation, vomiting, and respiratory distress. We describe a case of radiotracer accumulation over the liver dome on Tc-mebrofenin hepatobiliary scan performed on a 72-year-old man with acute cholecystitis mimicking a bile leak. However, chest radiograph and CT revealed intestinal hepatodiaphragmatic interposition. This case illustrates the importance of being familiar with the scintigraphic appearance of the Chilaiditi sign and correlating abnormal nuclear medicine scan findings with other available radiologic modalities.
Assuntos
Síndrome de Chilaiditi/diagnóstico por imagem , Colecistite Aguda/diagnóstico por imagem , Doenças da Vesícula Biliar/diagnóstico por imagem , Idoso , Compostos de Anilina , Bile/diagnóstico por imagem , Colecistostomia , Diagnóstico Diferencial , Diafragma/diagnóstico por imagem , Glicina , Humanos , Iminoácidos , Fígado/diagnóstico por imagem , Masculino , Compostos de Organotecnécio , Radiografia Torácica , Compostos Radiofarmacêuticos , Ruptura Espontânea/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Iminodiacetic acid (IDA) and tris(2-aminoethyl)amine (TREN) chelating ligands were immobilized on poly(ethylene vinyl alcohol) (PEVA) hollow-fiber membranes after activation with epichlorohydrin or butanediol diglycidyl ether (bisoxirane). The affinity membranes complexed with Cu(II) were evaluated for adsorption of human immunoglobulin G (IgG). The effects of matrix activation and buffer system on adsorption of IgG were studied. Isotherms of batch IgG adsorption onto finely cut membranes showed that neither of the chelates, IDA-Cu(II) or TREN-Cu(II), had a Langmuirean behavior with negative cooperativity for IgG binding. A comparison of equilibrium and dynamic maximum capacities showed that the dynamic capacity for a mini-cartridge in a cross-flow filtration mode (52.5 and 298.4 mg g(-1) dry weight for PEVA-TREN-Cu(II) and PEVA-IDA-Cu(II), respectively) was somewhat higher than the equilibrium capacity (9.2 and 73.3 mg g(-1) dry weight for PEVA-TREN-Cu(II) and PEVA-IDA-Cu(II), respectively). When mini-cartridges were used, the dynamic adsorption capacity of IDA-Cu(II) was the same for both mini-cartridge and agarose gel.
Assuntos
Cobre/química , Imunoglobulina G/isolamento & purificação , Adsorção , Cátions Bivalentes , Quelantes/química , Cromatografia de Afinidade , Epicloroidrina/química , Compostos de Epóxi/química , Etilenodiaminas/química , Iminoácidos/química , Cinética , Membranas Artificiais , Polivinil/química , Ligação Proteica , Soluções , TermodinâmicaRESUMO
BACKGROUND: Traumatic thoracobiliary fistula is a rare but serious complication. A series of thoracobiliary fistulas secondary to penetrating trauma and analysis of trends in management are presented. METHODS: We retrospectively reviewed all patients with traumatic thoracobiliary fistula, treated from April 2008 to February 2010. There were 5 patients: 4 suffered gunshot wounds and 1 was stabbed. The mean injury severity score was 22. RESULTS: Initial treatment was insertion of a chest tube in all cases. One patient underwent damage-control surgery and hepatic packing, and 3 were managed with laparotomy, a perihepatic closed drain, and suture of the diaphragm. Two patients developed bronchobiliary fistulas and 3 had pleurobiliary fistulas. Diagnostic procedures involved determination of bilirubin in pleural effusion, computed tomography, magnetic resonance cholangiography, hepatobiliary iminodiacetic scans, and endoscopic retrograde cholangiography. Definitive treatment included sphincterotomy and stenting in 4 cases, pulmonary decortication in 5, fistulectomy in 2, hepatic suture in 2, perihepatic closed drain placement in 4, and suture of the diaphragm in 4. CONCLUSIONS: Traumatic thoracobiliary fistulas are complex lesions. A multidisciplinary approach is required for a timely and successful outcome. Endoscopic retrograde cholangiography is very useful as the initial procedure to confirm the diagnosis and also for treatment.
Assuntos
Fístula Biliar/etiologia , Fístula Brônquica/etiologia , Doenças Pleurais/etiologia , Ferimentos por Arma de Fogo/complicações , Ferimentos Perfurantes/complicações , Adolescente , Adulto , Fístula Biliar/diagnóstico , Fístula Biliar/terapia , Bilirrubina/análise , Biomarcadores/análise , Fístula Brônquica/diagnóstico , Fístula Brônquica/terapia , Tubos Torácicos , Colangiopancreatografia Retrógrada Endoscópica , Colangiopancreatografia por Ressonância Magnética , Terapia Combinada , Drenagem , Feminino , Humanos , Iminoácidos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente , Doenças Pleurais/diagnóstico , Doenças Pleurais/terapia , Valor Preditivo dos Testes , Procedimentos Cirúrgicos Pulmonares , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Esfinterotomia Endoscópica , Stents , Técnicas de Sutura , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto JovemRESUMO
Endotoxins (also known as lipopolysaccharides (LPS)) are undesirable by-products of recombinant proteins, purified from Escherichia coli. LPS can be considered stable under a wide range of temperature and pH, making their removal one of the most difficult tasks in downstream processes during protein purification. The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration. Immobilized metal affinity chromatography (IMAC) enables the affinity interactions between the metal ions (immobilized on the support through the chelating compound) and the target molecules, thus enabling high-efficiency separation of the target molecules from other components present in a mixture. Affinity chromatography is applied with Ca2+ -iminodiacetic acid (IDA) to remove most of the LPS contaminants from the end product (more than 90%). In this study, the adsorption of LPS on an IDA-Ca2+ was investigated. The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal. It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads. The factors such as pH (4.0 or 5.5) and ionic strength (1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than 100 EU/mL and 100 000 EU/mL. This new protocol represents a substantial advantage in time, effort, and production costs.