RESUMO
We performed a genome-wide association study comparing a cohort of 144 human immunodeficiency virus (HIV type 1-infected, untreated white long-term nonprogressors (LTNPs) with a cohort of 605 HIV-1-infected white seroconverters. Forty-seven single-nucleotide polymorphisms (SNPs), located from class I to class III major histocompatibility complex (MHC) subregions, show statistical association (false discovery rate, <0.05) with the LTNP condition, among which 5 reached genome-wide significance after Bonferonni correction. The MHC LTNP-associated SNPs are ordered in ≥4 linkage disequilibrium blocks; interestingly, an MHC class III linkage disequilibrium block (defined by the rs9368699 SNP) seems specific to the LTNP phenotype.
Assuntos
Progressão da Doença , Genes MHC Classe I/genética , Infecções por HIV/genética , HIV-1 , Polimorfismo de Nucleotídeo Único , Proteínas de Ligação a DNA/genética , Frequência do Gene , Estudo de Associação Genômica Ampla , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Complexo Principal de Histocompatibilidade/genética , RNA Longo não Codificante , RNA não Traduzido , Fatores de Tempo , Fatores de Transcrição/genéticaRESUMO
Pharmacovigilance systems aim at early detection of adverse effects of marketed drugs. They maintain large spontaneous reporting databases for which several automatic signaling methods have been developed. One limit of those methods is that the decision rules for the signal generation are based on arbitrary thresholds. In this article, we propose a new signal-generation procedure. The decision criterion is formulated in terms of a critical region for the P-values resulting from the reporting odds ratio method as well as from the Fisher's exact test. For the latter, we also study the use of mid-P-values. The critical region is defined by the false discovery rate, which can be estimated by adapting the P-values mixture model based procedures to one-sided tests. The methodology is mainly illustrated with the location-based estimator procedure. It is studied through a large simulation study and applied to the French pharmacovigilance database.
Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos/estatística & dados numéricos , Algoritmos , Interpretação Estatística de Dados , Sistemas de Apoio a Decisões Clínicas , Reações Falso-Positivas , Reconhecimento Automatizado de Padrão/métodos , HumanosRESUMO
PURPOSE: The optimal dose in esophageal cancer patients treated with definitive chemoradiation (CRT) remains debated. We herein report on the dosimetric results, treatment-related toxicities and long-term outcomes of escalated dose up to 60Gy delivered with intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: All consecutive patients that received a definitive CRT>50Gy for an unresectable esophageal carcinoma between 2010 and 2015 were retrospectively evaluated for this study. Methodology included data base search, delayed toxicity grading, statistical testing including frequency analysis and survival analysis. RESULTS: A total of 51 patients were irradiated for a squamous cell carcinoma (86.3%) or an adenocarcinoma (13.7%). The median age at diagnosis was 62 years. Seven patients were simultaneously irradiated for another synchronous primary tumor. Forty-six patients (90.2%) received concurrent platin-based chemotherapy. The median prescribed doses were 60Gy (54-66) and 48Gy (44.8-56) delivered in 30 (27-35) fractions to the high and the low risks PTV respectively. The mean dose delivered to the lungs was 11.4Gy (IC 95%: 4.8-19.8), the median volumes receiving up to 20Gy (V20) and 30Gy (V30) were 13.5% (3.0-46.0) and 4.6% (0.7-19.8) respectively. The mean dose delivered to the heart was 13.9Gy (IC 95%:0.3-31.3) with a median V40 of 3.3% (0.0-25.0). One treatment-related death occurred within days after RT completion (neutropenic aplasia). After a median follow-up of 2.7 years (95% CI: 1.9-4.3), the 2-year overall survival, disease free survival and loco-regional control rates were 53.6%, 42.0% and 72.8% respectively. Delayed treatment related-toxicities ≤grade 3 occurred among 25 patients (62.5%) mostly esophageal stricture (79.2%). CONCLUSION: We demonstrated in this study that dose escalation using IMRT in combination with platin-based chemotherapy as a definitive treatment for esophageal carcinoma is safe and results in higher loco-regional and control survival when compared to previously reported data.
Assuntos
Adenocarcinoma/terapia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia/métodos , Neoplasias Esofágicas/terapia , Tolerância a Radiação , Radioterapia de Intensidade Modulada/métodos , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Quimiorradioterapia/efeitos adversos , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Estenose Esofágica/etiologia , Feminino , Fluoruracila/administração & dosagem , Coração/efeitos da radiação , Humanos , Leucovorina/administração & dosagem , Pulmão/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Órgãos em Risco/efeitos da radiação , Radioterapia de Intensidade Modulada/efeitos adversos , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Maintenance of nitric oxide (NO) homeostasis is an important concept for myocardial protection. Here, we have investigated the NO pathway by analysing total nitrate concentration (NOx) and NO synthase (NOS) isoforms expression as well as the myocardial integrity by lactate dehydrogenase and creatine kinase contents in the rat heart graft arrested by CRMBM solution, submitted to 3 hr cold ischemia in the same solution and 24 hr blood reperfusion following heterotopic abdominal heart transplantation. NOx level was similar to baseline value after ischemia and significantly increased after 24 hr reperfusion. NOS isoforms expression was highly modulated after cold ischemia followed by blood reperfusion. Endothelial NOS expression was decreased after ischemia but restored after 24 hr reperfusion. Neuronal NOS expression was drastically decreased after ischemia and 24 hr reperfusion. Inducible NOS protein was present only after 24 hr reperfusion. Cold ischemia induced a severe loss of creatine kinase without any modification after blood reperfusion. In conclusion, we show here that CRMBM solution did not increase NO production during ischemia but induced an enhanced synthesis of NO during reperfusion which may be related to restoration of endothelial NOS expression and/or induction of inducible NOS expression.
Assuntos
Temperatura Baixa , Transplante de Coração , Reperfusão Miocárdica , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico/biossíntese , Animais , Regulação Enzimológica da Expressão Gênica , Coração/fisiopatologia , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Isquemia Miocárdica/metabolismo , Óxido Nítrico/análise , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Ratos Endogâmicos Lew , Coleta de Tecidos e ÓrgãosRESUMO
Radiotherapy's main skin toxicities are now well-separated, acute (acute radiation dermatitis) or chronic complications (chronic radiation dermatitis, induced cutaneous carcinoma, aesthetic sequelae). Exceptionally, radiotherapy may induce, by isomorphic reaction or Koebner's phenomenon, some specific dermatosis. In this article, we report five new observations of these unusual complications of radiation therapy, occurring in very variable time after breast irradiation and remaining strictly localized in the irradiated field (cutaneous mastocytosis, Sweet syndrome, lichen planus, vitiligo). These cases emphasize the need to realize a systematic histological exam if any atypical skin lesion appears after radiotherapy, even long after.
Assuntos
Neoplasias da Mama/radioterapia , Lesões por Radiação/etiologia , Dermatopatias/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , HumanosRESUMO
Alpha-alumina is a useful thermoluminescence (TL) dosemeter. The knowledge of its behaviour under irradiation is thus of primary importance. The purpose of this paper is to characterise the radiation damage produced by swift krypton ions using various experimental methods, namely TL, optical absorption, fluorescence and electron paramagnetic resonance (EPR). After ion irradiation, the TL intensity is shown to decrease, whereas the optical absorption rises in the whole studied wavelength range. These two phenomena seem to be related to one another. Furthermore, optical absorption measurements highlight the appearance of new absorption bands probably owing to oxygen vacancies. Induced defects are also observed in the EPR spectra of irradiated pellets. They are likely related to electronic holes trapped on oxygen ions. The concentration of these defects increases with ion fluence and fluorescence measurements indicate that some pre-existing defects such as F2(2+) centres follow the same trend up to approximately 4.1 x 10(13) ions cm(-2).
Assuntos
Óxido de Alumínio/química , Óxido de Alumínio/efeitos da radiação , Íons Pesados , Temperatura Alta , Criptônio , Dosimetria Termoluminescente/métodos , Relação Dose-Resposta à Radiação , Teste de Materiais , Doses de Radiação , Dosimetria Termoluminescente/instrumentaçãoRESUMO
Recent studies have suggested the involvement of the nitric oxide (NO) pathway in ischemia-reperfusion injury related to cardiac transplantation. Herein, we assessed the NO pathway by quantifying endothelial (e) and inducible (i) nitric oxide synthase (NOS) expression and total NOS activity in a rat heart transplant model during cold ischemia with Celsior cardioplegia and reperfusion. Experiments were performed using a modified Lewis-Lewis heterotopic abdominal heart transplantation with 3 or 6 hours of ischemia with or without 1 hour of blood reperfusion. NOS expression and activity were determined using Western blotting and colorimetric assays, respectively, on freeze-clamped hearts after ischemia without (n = 10) or with reflow (n = 12) compared with basal values. Hearts submitted to 3 hours of ischemia and 1 hour of reperfusion showed a postischemic rate pressure product of 5190 +/- 3047 mm Hg/min (reversible ischemia), but no contractility was observed after 6 hours of ischemia. eNOS protein levels were lower after 3 hours of ischemia compared with the basal value (P = .0005) and were further decreased after 6 hours of ischemia (P < .0001 versus basal value and P = .0018 versus 3 hours of ischemia). Reperfusion did not further decrease eNOS protein levels. iNOS protein was not detected in any condition. NOS activity was increased after 3 hours of ischemia versus basal value (P = .0065) but not after 6 hours of ischemia without any effect of reperfusion. We concluded that eNOS expression was altered during ischemia and the amplitude of the alteration depended on the duration of ischemia. Reversible ischemia was associated with increased NOS activity at the end of ischemia with no variation at reperfusion.
Assuntos
Transplante de Coração/fisiologia , Óxido Nítrico/fisiologia , Traumatismo por Reperfusão/fisiopatologia , Animais , Pressão Sanguínea , Modelos Animais , Contração Miocárdica , Isquemia Miocárdica/fisiopatologia , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Ratos Endogâmicos Lew , Fatores de Tempo , Transplante IsogênicoRESUMO
A specific radioimmunoassay method for rat erythrocyte carbonic anhydrases I and II was developed using a double antibody system. Its sensitivity was in the nanogram range for each of the two isozymes. The method has been applied to the assay of cerebral carbonic anhydrase. Only CAII has been found in brain extracts of perfused rats. Accordingly, the assay of CAI in cerebral tissue can be used to quantify erythrocyte contamination on condition that the ratio CAII/CAI in blood had been worked out. The developmental change in the soluble and the Triton X-100 solubilized brain CAII from birth to adult is reported.
Assuntos
Encéfalo/metabolismo , Anidrases Carbônicas/metabolismo , Isoenzimas/metabolismo , Envelhecimento , Animais , Animais Recém-Nascidos , Encéfalo/crescimento & desenvolvimento , Masculino , Radioimunoensaio , RatosRESUMO
Bovine erythrocyte carbonic anhydrase CI consists of 259 amino acid residues including 18 lysines and 9 arginines. Its primary structure has been first investigated by isolation and sequence determination of the tryptic units. Acidification of the tryptic hydrolysate leads to the precipitation of 40% of the peptidic material. All the acid soluble peptides were isolated from the supernatant by chromatography on Dowex 50 W-X2 and Dowex 1-X2 followed by purification of heterogeneous fractions. Two of the three acid insoluble peptides were obtained in a pure form from the whole tryptic hydrolysate by gel filtration on Sephadex G-50 and chromatography on DEAE-Sephadex in alkaline medium. The sequence of the so isolated tryptic units has been determined with the exception of two of them obtained in a very poor yield.
Assuntos
Anidrases Carbônicas/sangue , Eritrócitos/enzimologia , Sequência de Aminoácidos , Animais , Bovinos , Concentração de Íons de Hidrogênio , Fragmentos de Peptídeos/isolamento & purificação , Solubilidade , TripsinaRESUMO
A comparative study of 24 hr preservation at 4 degrees C of excised rat livers with Euro-Collins and hydroxyethyl starch-free University of Wisconsin (UWm) solutions has been conducted based on the assessment of (1) the cellular energy status determined by 31P NMR spectroscopy and (2) cellular injury estimated from the loss of purine compounds (inosine, hypoxanthine, xanthine, and uric acid) during cold ischemia and reperfusion measured by HPLC, the leakage of intracellular enzymes, and the modifications of parenchyma established by light microscopy. Recovery of nucleosides di- and triphosphate was greater in the UWm group (80 +/- 6% vs. 58 +/- 6%) while inorganic phosphate formation was comparatively reduced. During hypothermic storage, the UWm groups generated a higher amount of inosine and hypoxanthine (in relation to the presence of adenosine in the protective solution) while no xanthine or uric acid was detected due to the inhibitory effect of allopurinol. Conversely, large quantities of xanthine and uric acid were found in the reperfusate of the EC group, pinpointing the cytotoxic role of oxygen-derived free radicals in the generation of cellular damage, as also illustrated by a higher aspartate aminotransferase leakage in the EC group (devoid of allopurinol and glutathione. Light microscopy indicated no histological alterations in the UWm group and mild alterations in the EC group that showed ballooning of hepatocytes (no lactobionate and raffinose in EC) and an alternation of clarifications and eosinophilic condensations. This study clearly confirms and illustrates the overall superiority of UWm solution in liver transplant preservation.
Assuntos
Soluções Hipertônicas , Fígado , Soluções para Preservação de Órgãos , Soluções , Preservação de Tecido/métodos , Adenosina , Alopurinol , Animais , Aspartato Aminotransferases/análise , Glutationa , Hipotermia Induzida , Insulina , L-Lactato Desidrogenase/análise , Espectroscopia de Ressonância Magnética , Masculino , Microscopia , Purinas/metabolismo , Rafinose , Ratos , Fatores de TempoRESUMO
Glucose-6-phosphatase (G6Pase) is a multicomponent system that catalyzes G6P hydrolysis. To determine the specificity of the histochemical reaction of G6Pase, we investigated the inhibitory effect of diethyl pyrocarbonate (DEPC), a specific and very effective inhibitor of the phosphohydrolase component of the G6Pase system, in normal human liver. The inactivation of the histochemical enzymatic activity by DEPC was monitored by determining the mean brightness of the microscopic image and the histogram of light intensity distributions. The results obtained indicate that the histogram is more sensitive than the mean brightness to variations of enzymatic activities, and that the percent of pixels brighter than a convenient level is directly proportional to DEPC concentration. This study indicates that DEPC can be used as an efficient inhibitor of the histochemical reaction of G6Pase.
Assuntos
Dietil Pirocarbonato/farmacologia , Glucose-6-Fosfatase/antagonistas & inibidores , Histocitoquímica/métodos , Processamento de Imagem Assistida por Computador/métodos , Fígado/enzimologia , Ativação Enzimática/efeitos dos fármacos , Feminino , Glucose-6-Fosfatase/metabolismo , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: When analysing data which simultaneously implicate a large number of statistical tests, one of the main problems is to take into account the multiplicity of these tests. The huge amount of comparisons done in studies of which the aim is to detect, using microarray, genes whose transcriptional changes are related to a biological or clinical outcome leads to a renewed interest for the multiple comparisons problem. However, this problem concerns many other fields such as psychometry, epidemiology, genetics. RESULTS: First, we introduce the multiple comparison framework. Then, we present the main procedures based on a global error rate called the "Family Wise Error Rate" (FWER) and those based on a false discovery rate expectancy (the "False Discovery Rate" (FDR) and the "positive False Discovery Rate" (pFDR)). Next, we apply the different procedures on a real dataset from a breast carcinoma study. Finally, we discuss the main results and we present guidelines for the use of these procedures.
Assuntos
Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reações Falso-Positivas , Genótipo , Humanos , Fenótipo , Análise de Sequência/métodosRESUMO
The authors report an exceptional case of complex monoclonal dysglobulinaemia characterized by cryoglobulinaemia, pseudoanalbuminaemia and acquired type 1 Von Willebrand's disease. All these biological abnormalities are consecutive to the formation of molecular complexes in vivo. These complexes have also been found in vitro between albumin immunoglobulins G.
Assuntos
Crioglobulinemia/complicações , Disgamaglobulinemia/complicações , Imunoglobulina M/deficiência , Albumina Sérica/deficiência , Doenças de von Willebrand/complicações , Eletroforese em Acetato de Celulose , Humanos , Imunoglobulina M/análise , Masculino , Pessoa de Meia-Idade , Albumina Sérica/análiseRESUMO
BACKGROUND: We measured the functional and metabolic status of hearts submitted to normothermic ischemia before preservation through the use of an ex vivo pig heart model to assess the feasibility of donation after cardiac death (DCD) in heart transplantation. METHODS: Ten pigs were separated into 2 groups: control (n = 6, brain-dead group) and DCD (n = 4, heart donation after cardiac death). In the control group, hearts were excised 20 minutes after the brachiocephalic trunk cross-clamping and were immediately reperfused. In DCD, hearts were excised 20 minutes after exsanguination and asphyxia, stored in the Centre de Résonance Magnétique Biologique et Médicale (CRMBM) solution for 2 hours, and then were reperfused. Cardioplegic arrest was induced with the use of 1 L of CRMBM solution (4°C) and the heart was reperfused for 60 minutes through the use of an ex vivo perfusion system in Langendorff mode with normothermic autologous blood. During reperfusion, functional parameters were analyzed. Biochemical assays were performed in myocardial effluents and freeze-clamped hearts. RESULTS: No electromechanical activity was found in DCD compared with control. Creatine kinase (CK) was higher at 2 minutes of reperfusion in DCD versus control (P = .005). Adenosine triphosphate was lower in DCD versus control (P = .0019). Malondialdehyde, an oxidative stress index, was present only in DCD. The nitric oxide (NO) pathway was impaired in DCD versus control, with lower eNOS expression (P < .0001) and total nitrate concentration content (P = .04). CONCLUSIONS: We reported no cardiac functional and metabolic recovery in the DCD group after normothermic ischemia and reperfusion, which indicates that a single immersion of the cardiac graft during storage does not provide an optimal protection. New strategies in heart preservation are necessary for recruiting heart donation after cardiac death.
Assuntos
Parada Cardíaca Induzida/métodos , Transplante de Coração , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Obtenção de Tecidos e Órgãos/métodos , Animais , Modelos Animais de Doenças , Coração , Miocárdio/patologia , SuínosRESUMO
Although it has been suggested that the skeletal muscle mitochondrial uncoupling protein-3 (UCP3) is involved in regulating energy expenditure, its role is still poorly understood. In the present study, we aimed at investigating noninvasively, using magnetic resonance techniques, metabolic changes occurring in exercising muscle as a result of capsiate treatment, which has been previously linked to UCP3 upregulation. We showed that capsiate ingestion strongly reduced UCP3 gene expression in rat gastrocnemius muscle. This large underexpression was accompanied by a significant increase in the rate of mitochondrial ATP production and phosphocreatine level both at rest and during muscle stimulation. Similarly, the stimulation-induced ATP fall and ADP accumulation were significantly less after capsiate administration than in untreated rats. The larger oxidative ATP production rate could not be explained by a proportional decrease in the anaerobic component, i.e., glycolysis and phosphocreatine breakdown. In addition, the mechanical performance was not affected by capsiate administration. Finally, the plasma free fatty acid (FFA) level increased in capsiate-treated rats, whereas no significant change was observed after muscle stimulation in the control group. Considering the corresponding enhanced UCP3 mRNA expression occurring in the control group after muscle stimulation, one can suggest that changes in FFA level and UCP3 mRNA expression are not mechanistically correlated. Overall, we have shown that capsiate administration induced a UCP3 downregulation coupled with an increased mitochondrial ATP synthesis, whereas the muscle force-generating capacity was unchanged. This suggests that a decrease in muscle efficiency and/or additional noncontractile ATP-consuming mechanisms result from UCP3 downregulation.
Assuntos
Analgésicos não Narcóticos/farmacologia , Capsaicina/análogos & derivados , Canais Iônicos/metabolismo , Mitocôndrias Musculares/metabolismo , Proteínas Mitocondriais/metabolismo , Músculo Esquelético/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Capsaicina/farmacologia , Regulação para Baixo/efeitos dos fármacos , Estimulação Elétrica , Metabolismo Energético , Ácidos Graxos não Esterificados/sangue , Feminino , Concentração de Íons de Hidrogênio , Canais Iônicos/biossíntese , Canais Iônicos/genética , Espectroscopia de Ressonância Magnética , Mitocôndrias Musculares/efeitos dos fármacos , Proteínas Mitocondriais/biossíntese , Proteínas Mitocondriais/genética , Músculo Esquelético/efeitos dos fármacos , Fosfocreatina/metabolismo , Ratos , Ratos Sprague-Dawley , Proteína Desacopladora 3RESUMO
To investigate the influence of maternal smoke exposure on neonatal and maternal antioxidant status, 39 mothers who were active smokers, 14 mothers exposed to environmental tobacco smoke (ETS), 17 controls, and their newborns were included in a prospective, controlled study. Plasma total antioxidant capacity, measured as total radical-trapping antioxidant parameter (TRAP) and ferric reducing antioxidant power (FRAP), and concentrations of specific antioxidants were measured in cord and in maternal blood. A similar, significant increase in ceruloplasmin concentration was observed in neonates born to actively smoking mothers and in those born to ETS exposed mothers. Uric acid and TRAP concentrations were significantly increased in ETS-exposed newborns and their mothers, compared to newborns and mothers from the active smoking and no-exposure groups with a trend towards increased uric acid, TRAP and FRAP concentrations being observed in the active smokers group. Neonatal and maternal antioxidant concentrations correlated significantly, except for ceruloplasmin. Cord blood vitamin A, E and C concentrations were unaffected by smoke exposure. These results show that maternal active smoking as well as ETS exposure significantly affect neonatal and maternal antioxidant status.
Assuntos
Antioxidantes/análise , Sangue Fetal/química , Troca Materno-Fetal , Fumar/efeitos adversos , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Ácido Ascórbico/sangue , Ceruloplasmina/análise , Feminino , Compostos Férricos/química , Radicais Livres/química , Humanos , Recém-Nascido , Gravidez , Estudos Prospectivos , Ácido Úrico/sangue , Vitamina A/sangue , Vitamina E/sangueRESUMO
The effects of 'third-generation' cephalosporins and penicillin analogues on the concentrations of total unconjugated bilirubin, unbound bilirubin and erythrocyte-bound bilirubin were determined in blood samples. This study was performed, in vitro, at two bilirubin/albumin molar ratios and at various concentrations of antibiotics. The most effective displacers, considering the three methods, were antibiotics tightly bound to albumin: ceftriaxone and cefotetan. Cefoperazone, which is bound to albumin as tightly as these two antibiotics, caused no significant increase in unbound bilirubin but should be considered as a displacer drug on the basis of the variations of erythrocyte-bound bilirubin and total bilirubin. We suggest that drug interaction on bilirubin-albumin binding be investigated by several methods.
Assuntos
Antibacterianos/metabolismo , Bilirrubina/metabolismo , Eritrócitos/metabolismo , Albumina Sérica/metabolismo , Antibacterianos/sangue , Antibacterianos/farmacologia , Bilirrubina/sangue , Interações Medicamentosas , Eritrócitos/análise , Humanos , Ligação Proteica/efeitos dos fármacos , Albumina Sérica/análise , beta-LactamasRESUMO
Determination of 'free' bilirubin, erythrocyte-bound bilirubin and unconjugated bilirubin was used to test the effects of ceftriaxone on the binding of bilirubin to albumin. This study, performed on blood samples from icteric neonates, showed that the addition of ceftriaxone produced an increase of free bilirubin and erythrocyte-bound bilirubin and a decrease of unconjugated bilirubin. Ceftriaxone displays a significant displacing effect at concentrations obtained during therapeutic use and should be used with caution in high-risk jaundiced infants.
Assuntos
Bilirrubina/metabolismo , Ceftriaxona/farmacologia , Eritrócitos/metabolismo , Humanos , Recém-Nascido , Albumina Sérica/metabolismoRESUMO
The effects of ceftriaxone, a 'third-generation' cephalosporin, on bilirubin-serum albumin complexes were investigated. This study was performed on human adult samples at various bilirubin-albumin ratios. Ceftriaxone caused a decrease of unconjugated bilirubin and simultaneously an increase of erythrocyte-bound bilirubin. These variations were proportionally more important for low concentrations of antibiotic, including therapeutic values. It was concluded that ceftriaxone competes with bilirubin and displaces it from albumin-binding sites.
Assuntos
Bilirrubina/sangue , Ceftriaxona/sangue , Membrana Eritrocítica/metabolismo , Albumina Sérica/metabolismo , Ligação Competitiva , Humanos , Técnicas In Vitro , Ligação ProteicaRESUMO
1. Isolated carbonic anhydrases CA I and CA II from different species (man, ox, sheep, pig, dog and rat) have been analyzed by immunodiffusion techniques using rabbit specific CA I or CA II antisera. 2. Immunodiffusion shows the absence of cross-reactivity between CA I and CA II isoenzymes. 3. Common antigenic determinants (cross-reactivities) were evidenced between the CA I of the different species under study. 4. To the contrary, cross-reactivity between CA II of the species mentioned above, can clearly be demonstrated only between bovine and sheep CA II.