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BACKGROUND & AIMS: In the year 2022, an outbreak of indeterminate acute hepatitis and indeterminate paediatric acute liver failure (ID-PALF) in association with adenoviraemia in immunocompetent children was reported in the UK. We postulate that this association is not a new disease in immunocompetent children. METHODS: Children with acute hepatitis during the outbreak who were referred to King's College Hospital, London for advice and management were included in the study. Data on the frequency of ID-PALF in 2022, as well as transplantation rates and the association with adenovirus infection, were obtained from electronic health records. The clinical presentation, histology and outcomes of children with ID-PALF and adenoviraemia in 2017-2021 were compared with those in 2022. RESULTS: From January to June 2022, 65 patients with acute hepatitis were referred. Ten children were admitted with ID-PALF. ID-PALF constituted 26% of all PALF cases in 2017-2021, in contrast to 58.8% during the 2022 outbreak. During the outbreak, adenoviraemia was present in 52% of children with acute hepatitis without liver failure (in whom adenoviraemia test results were available) and in 100% of ID-PALF cases. Adenoviraemia was seen in immunocompetent children in 6/13 (46%) of all ID-PALF cases between 2017-2019, with a clear absence of adenoviraemia in the 6 ID-PALF cases during 2020-2021. Compared to ID-PALF with adenoviraemia in 2017-2019 (n = 6), ID-PALF with adenoviraemia during the outbreak (n = 10) was associated with more frequent hepatic encephalopathy, hypotension requiring vasoactive medications and higher plasma ammonia levels (admission and peak), with similar native liver survival. CONCLUSIONS: The recent outbreak of ID-PALF with adenoviraemia in immunocompetent children does not appear to be a new disease, contrary to perception and other reports. The frequency of such cases over the years could be linked to background rates of adenovirus infections. IMPACT AND IMPLICATIONS: Indeterminate paediatric acute liver failure (ID-PALF) associated with adenoviraemia in immunocompetent children is not a new disease specific to 2022. The exclusive role of human adenovirus infection in the causation of this outbreak of acute hepatitis seems unlikely. Indeed, we provide histological data from explants in transplanted patients that do not support direct viral cytotoxicity. The disease is probably mediated by immunological injury directed towards adenovirus infection and/or adeno-associated virus-2.
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Infecções por Adenoviridae , Hepatite , Falência Hepática Aguda , Humanos , Criança , Falência Hepática Aguda/etiologia , Falência Hepática Aguda/complicações , Infecções por Adenoviridae/complicações , Doença Aguda , Surtos de DoençasRESUMO
Since April 2022, over 1000 children across 35 countries have developed episodes of acute hepatitis of unknown origin. At King's College Hospital, a total of 65 children were referred with acute hepatitis of unknown etiology, with 10 of these children presenting with acute liver dysfunction leading to acute liver failure. Multiple hypotheses have been proposed and continue to be investigated worldwide. In this review, we explore the current understanding of potential aetiologies for this outbreak. We further characterize the proposed immunological mechanisms of liver injury in these cases.
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Hepatite , Falência Hepática Aguda , Humanos , Criança , Prognóstico , Falência Hepática Aguda/etiologia , Hepatite/complicações , Doença Aguda , Surtos de DoençasRESUMO
Dy3+ -doped CaY2 Al4 SiO12 phosphors were prepared using the sol-gel method. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy analyses (EDS) were used to analyse the crystal structure, morphology, and elemental composition of the prepared samples. The luminescence behaviour of the sample was investigated using photoluminescence (PL) and thermoluminescence (TL) techniques. The prepared CaY2 Al4 SiO12 :xDy3+ phosphor showed a characteristic blue and yellow emission at ~480 and 583 nm, respectively, with an excitation wavelength of 350 nm. The most intense PL emission was found for a 4 mol% doping concentration of Dy3+ ions. The CIE diagram of the phosphor showed bluish-white colour emission. For TL studies, the prepared phosphors were irradiated with a 60 Co γ (gamma) source and the TL glow curve of the CaY2 Al4 SiO12 :0.04Dy3+ phosphor showed three overlapped peaks. For the Gaussian peaks, Chen's peak shape method was applied to determine the kinetic parameters of the samples.
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Luminescência , Difração de Raios X , Raios gama , Cinética , Microscopia Eletrônica de VarreduraRESUMO
Low aqueous solubility, adverse effects of Cisplatin includes hepatotoxicity and nephrotoxicity necessitates development of nanoparticulate drug delivery. The study pertains to development of CisNLC (Cisplatin loaded Nanostructured Lipid Carrier) by ultrasonication. Physical characterisation includes particle size, zeta potential, TEM, SEM-EDX, DSC. Its ex vivo biocompatibility, pharmacokinetics and biodistribution along with acute toxicity induced oxidative stress in Balb/c mice were evaluated. The mean particle diameter of CisNLC was observed to be 141.5 ± 3.86 nm with zeta potential of -41.5 ± 1.62 mV. In vitro release studies at pH 7.4 and 5.8 showed burst release following a sustained release pattern post-72 h. CisNLC showed anticancer efficacy against PA-1. Negligible ex vivo haemolysis indicated bio-compatibility. Improved pharmacokinetics of CisNLC was observed. Acute toxicity and oxidative stress evaluation proved negligible toxicity by CisNLC. The formulated CisNLC had a good physical stability, biocompatible, indicated enhanced circulation and caused negligible toxicity on liver and kidney as compared to pure Cis.
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Cisplatino , Nanoestruturas , Camundongos , Animais , Cisplatino/farmacologia , Distribuição Tecidual , Lipídeos , Sistemas de Liberação de Medicamentos , Tamanho da Partícula , Portadores de Fármacos/farmacocinéticaRESUMO
The emergence of multi-drug resistant bacterial infections has resulted in increased interest in the development of alternative systems which can sensitize bacteria to overcome resistance. In an attempt to contribute to the existing literature of potential antibacterial agents, we present here, a first report of the antibacterial potential of FeCo nanoparticles, both as stand-alone devices and in presence of magnetic field, against the bacterial strains of S. aureus and E. coli. A relatively simple polyol process was employed for nanoparticle synthesis. Formation of FeCo alloy in the desired BCC phase was confirmed by X-Ray Diffraction with a high saturation magnetization (Ms~180 Am2kg-1). Uniformly sized spherical structures with sharp edges were obtained. Solution stability was confirmed by the zeta potential value of -27.8 mV. Dose dependent bacterial growth inhibition was observed, the corresponding linear correlation coefficients being, R2 = 0.74 for S. aureus and R2 = 0.76 for E. coli. Minimum inhibitory concentration was accordingly ascertained to be >1024 µg/ml for both. Bacterial growth curves have been examined upon concomitant application of external magnetic field of varying intensities and revealed considerable enhancement in the antibacterial response upto 63% in a field of 100 mT. An effort has been made to understand the bacterial inhibitory mechanism by relating with the chemical and physical properties of the nanoparticles. The ease of field assisted targeting and retrieval of these highly magnetic, antibacterial nano-devices, with considerably improved response with magnetic fields, make them promising for several medical and environment remediation technologies.
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ABSTRACT: Biliary atresia (BA) is a fibro-obliterative condition of the biliary tree, presenting in infancy. The bilioenteric conduit formed at Kasai portoenterostomy (KPE), achieves restoration of bile flow in approximately 60% of infants. Even if the operation is successful, cirrhosis and its associated complications are, however, common. BA remains the leading cause for liver transplantation (LT) in children. Antibiotic, choleretic, and steroid therapy post-KPE have not convincingly reduced LT rates. Advances in molecular technology have enabled characterisation of the encoded genes of the gut microbiota (gut microbiome). The gut microbiome plays an important role in host metabolism, nutrition, and immune function, with alterations in its diversity and/or composition, known as dysbiosis, being described in disease states, including liver disease. Liver-gut microbiome exploration in adulthood largely focuses on nonalcoholic liver disease, cirrhosis (mainly alcohol- or viral-based aetiology) and cholestatic liver diseases (eg, primary sclerosing cholangitis), with microbial signatures correlating to disease severity. Investigation of the gut microbiota in BA had been limited to culture-based methodology, but molecular studies are emerging, and although in their infancy, highlight a potential pathogenic role for Enterobacteriaceae and Streptococcus, and a potential beneficial role for Bifidobacteria. Bacterial translocation, and the production of gut microbiome-derived metabolites, are key host-microbiome-mechanistic pathways in liver disease pathogenesis. Microbiome-targeted therapeutics for liver disease are in development, with faecal microbiota transplantation showing promise in cirrhosis. Could the gut microbiome be a novel modifiable risk factor in BA, reducing the need for LT?
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Atresia Biliar , Microbioma Gastrointestinal , Adulto , Atresia Biliar/etiologia , Criança , Disbiose , Transplante de Microbiota Fecal , Humanos , Lactente , Fatores de RiscoRESUMO
The COVID-19 pandemic has proven to be a challenge in regard to the clinical presentation, prevention, diagnosis, and management of SARS-CoV-2 infection among children who are candidates for and recipients of SOT. By providing scenarios and frequently asked questions encountered in routine clinical practice, this document provides expert opinion and summarizes the available data regarding the prevention, diagnosis, and management of SARS-CoV-2 infection among pediatric SOT candidates and recipients and highlights ongoing knowledge gaps requiring further study. Currently available data are still lacking in the pediatric SOT population, but data have emerged in both the adult SOT and general pediatric population regarding the approach to COVID-19. The document provides expert opinion regarding prevention, diagnosis, and management of SARS-CoV-2 infection among pediatric SOT candidates and recipients.
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COVID-19/complicações , Doença Hepática Terminal/cirurgia , Transplante de Fígado/efeitos adversos , Transplante de Pulmão/efeitos adversos , SARS-CoV-2 , Transplantados , Adolescente , Criança , Pré-Escolar , Reações Falso-Positivas , Feminino , Humanos , Hospedeiro Imunocomprometido , Masculino , Transplante de Órgãos , Pandemias , Segurança do Paciente , Período Pós-Operatório , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Risco , Fatores de RiscoRESUMO
BACKGROUND & AIMS: Liver transplantation (LT) is the most effective treatment for patients with acute liver failure (ALF), but is limited by surgical risks and the need for life-long immunosuppression. Transplantation of microencapsulated human hepatocytes in alginate is an attractive option over whole liver replacement. The safety and efficacy of hepatocyte microbead transplantation have been shown in animal models. We report our experience of this therapy in children with ALF treated on a named-patient basis. METHODS: Clinical grade human hepatocyte microbeads (HMBs) and empty microbeads were tested in immunocompetent healthy rats. Subsequently, 8 children with ALF, who were awaiting a suitable allograft for LT, received intraperitoneal transplantation of HMBs. We monitored complications of the procedure, assessing the host immune response and residual function of the retrieved HMBs, either after spontaneous native liver regeneration or at the time of LT. RESULTS: Intraperitoneal transplantation of HMBs in healthy rats was safe and preserved synthetic and detoxification functions, without the need for immunosuppression. Subsequently, 8 children with ALF received HMBs (4 neonatal haemochromatosis, 2 viral infections and 2 children with unknown cause at time of infusion) at a median age of 14.5 days, range 1 day to 6 years. The procedure was well tolerated without complications. Of the 8 children, 4 avoided LT while 3 were successfully bridged to LT following the intervention. HMBs retrieved after infusions (at the time of LT) were structurally intact, free of host cell adherence and contained viable hepatocytes with preserved functions. CONCLUSION: The results demonstrate the feasibility and safety of an HMB infusion in children with ALF. LAY SUMMARY: Acute liver failure in children is a rare but devastating condition. Liver transplantation is the most effective treatment, but it has several important limitations. Liver cell (hepatocyte) transplantation is an attractive option, as many patients only require short-term liver support while their own liver recovers. Human hepatocytes encapsulated in alginate beads can perform the functions of the liver while alginate coating protects the cells from immune attack. Herein, we demonstrated that transplantation of these beads was safe and feasible in children with acute liver failure.
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Alginatos , Encapsulamento de Células/métodos , Hepatócitos/transplante , Falência Hepática Aguda/cirurgia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Microesferas , Animais , Células Cultivadas , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Humanos , Lactente , Recém-Nascido , Regeneração Hepática , Masculino , Modelos Animais , Ratos , Obtenção de Tecidos e Órgãos/métodos , Transplante Heterólogo/métodos , Transplante Homólogo/métodos , Resultado do TratamentoRESUMO
Coronavirus disease 2019 (COVID-19) caused by a novel coronavirus called severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is driving a present day global pandemic. Immunosuppressed patients are regarded as a high-risk cohort. The following is a short report on COVID-19 in liver transplant recipients (n = 5) from a high volume UK liver transplant unit with a large follow-up cohort (n = 4500). Based on this limited data, liver transplant recipients appear to have a low incidence of COVID-19, with less severe symptoms than expected, when compared with the general population and other solid organ recipients. This possibly could be related to self-isolation adherence and/or the 'ideal' level of immunosuppression that favourably modulates the immune response to COVID-19.
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Betacoronavirus , Infecções por Coronavirus/epidemiologia , Transplante de Fígado , Pneumonia Viral/epidemiologia , Adulto , COVID-19 , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Prevalência , SARS-CoV-2RESUMO
OBJECTIVES: Acute-on-chronic liver failure (ACLF) is an acute decompensation of cirrhosis complicated by other organ failure and is associated with increased mortality and morbidity. ACLF has not been studied in children with biliary atresia (BA), which is the commonest indication for pediatric liver transplantation (LT) worldwide. This study aims to evaluate ACLF and outcomes in children with BA while awaiting deceased donor LT. METHODS: This was a subanalysis of the dataset from a prospective cohort study of patients aged 0-18 years who underwent portoenterostomy for BA and were listed for LT at King's College Hospital, London, between 1999 and 2003. Outcomes included the development of ACLF, mortality, and complications. RESULTS: Ninety-nine (41 male) children were included, and follow-up was 10 [6.0-15.0] years. A total of 20/99 children developed ACLF. ACLF was associated with increased mortality while awaiting LT (20% vs 4%; P = 0.03). There were no associations between biochemical parameters at listing and death. Increased bilirubin levels 3 months post-portoenterostomy was predictive of development of ACLF (AUROC = 0.72, P < 0.01). Age at LT and time on the waiting list in the ACLF subgroup were both lower compared to the non-ACLF group (P > 0.05). Sepsis and gastrointestinal bleeding were the commonest precipitants of ACLF. Complications included ascites, hepatic encephalopathy, and hepatorenal syndrome; the ACLF subgroup required multisystem support and longer intensive care unit stay. CONCLUSIONS: ACLF in children with BA awaiting deceased donor LT carries increased mortality and morbidity. This warrants stratification of patients for earlier wait-listing and prioritization for LT.
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Insuficiência Hepática Crônica Agudizada/etiologia , Atresia Biliar/complicações , Transplante de Fígado , Listas de Espera , Insuficiência Hepática Crônica Agudizada/diagnóstico , Insuficiência Hepática Crônica Agudizada/epidemiologia , Adolescente , Atresia Biliar/mortalidade , Atresia Biliar/cirurgia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Portoenterostomia Hepática , Prognóstico , Estudos Prospectivos , Fatores de RiscoRESUMO
INTRODUCTION: The presence of infections in the immediate pretransplant period poses challenges in decision-making. Delaying transplantation because of these infections may be required, but is associated with a risk to the potential recipient. The aim of this project was to develop a structured framework based on expert opinion to guide decision-making regarding the safety of transplantation for candidates with infection immediately before transplant, and to show how this framework can be applied to clinical scenarios. METHODS: Categories were created as follows: Category A: no delay; Category B: brief delay (≤1 week); Category C: intermediate delay (>1 week); and Category D: more prolonged or indefinite delay. A survey containing 59 clinical scenarios was sent to members of the IPTA ID CARE committee. Answers were reviewed, and the level of agreement was characterized as follows: Level 1: ≥75% agreement; Level 2:51%-74% agreement; and Level 3: ≤50% agreement. 95% CIs were calculated for the mean overall agreement across 59 scenarios. RESULTS: Among the panel, the agreement level ranged from 33% to 92% with the mean overall agreement across the 59 scenarios being 61%. For 7/59 scenarios, the lower bound of 95% CI was greater than 50%, indicating a difference at the 5% level of significance between the observed proportion and the chance level of 0.5. SUMMARY: The document provides expert opinion regarding the need to delay transplantation in the setting of different infections. The most important points in the decision to proceed to SOT included the urgency of transplantation and the severity of infection.
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Tomada de Decisões , Infecções , Transplante de Órgãos/métodos , Bacteriemia/complicações , Infecções Bacterianas/complicações , Infecções do Sistema Nervoso Central/complicações , Criança , Humanos , Micoses/complicações , Segurança do Paciente , Pediatria/métodos , Infecções Respiratórias/complicações , Risco , Transplantes , Infecções Urinárias/complicações , Viroses/complicaçõesRESUMO
Growing evidence suggests receipt of live-attenuated viral vaccines after solid organ transplant (SOT) has occurred and is safe and needed due to lapses in herd immunity. A 2-day consortium of experts in infectious diseases, transplantation, vaccinology, and immunology was held with the objective to review evidence and create expert recommendations for clinicians when considering live viral vaccines post-SOT. For consideration of VV and MMR post-transplant, evidence exists only for kidney and liver transplant recipients. For MMR vaccine post-SOT, consider vaccination during outbreak or travel to endemic risk areas. Patients who have received antiproliferative agents (eg. mycophenolate mofetil), T cell-depleting agents, or rituximab; or have persistently elevated EBV viral loads, or are in a state of functional tolerance, should be vaccinated with caution and have a more in-depth evaluation to define benefit of vaccination and net state of immune suppression prior to considering vaccination. MMR and/or VV (not combined MMRV) is considered to be safe in patients who are clinically well, are greater than 1 year after liver or kidney transplant and 2 months after acute rejection episode, can be closely monitored, and meet specific criteria of "low-level" immune suppression as defined in the document.
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Transplante de Órgãos , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/prevenção & controle , Vacinas Atenuadas , Viroses/prevenção & controle , Criança , Humanos , Pediatria , Cuidados Pós-Operatórios/normas , Viroses/etiologiaRESUMO
The aim of this investigation is the management of rheumatoid arthritis (RA) by developing methotrexate-loaded calcium phosphate nanoparticles (MTX-CAP-NP) and to evaluate pharmacokinetic and pharmacodynamic behavior in adjuvant induced arthritis model. The nanoparticles were synthesized by wet precipitation method and optimized by Box-Behnken experimental design. MTX-CAP-NPs were characterized by TEM, FTIR, DSC and XRD studies. The particle size, zeta potential and entrapment efficiency of the optimized nanoparticles were found to be 204.90 ± 64 nm, -11.58 ± 4.80 mV, and 88.33 ± 3.74%, respectively. TEM, FTIR, DSC and XRD studies revealed that the developed nanoparticles were nearly spherical in shape and the crystalline structure of CAP-NP was not changed after MTX loading. The pharmacokinetic studies revealed that MTX-CAP-NP enhanced bioavailability of MTX by 2.6-fold when compared to marketed formulation (FOLITRAX-10). Under pharmacodynamic evaluation, arthritic assessment, radiography and histopathology studies revealed that CAP has ability to regenerate cartilage and bone therefore, together with MTX, MTX-CAP-NPs have shown significant reduction in disease progression. The overall work demonstrated that the developed nanodelivery system was well tolerated and more effective than the marketed formulation.
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Fosfatos de Cálcio/química , Metotrexato/química , Metotrexato/farmacocinética , Nanopartículas/química , Animais , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Disponibilidade Biológica , Portadores de Fármacos/química , Feminino , Metotrexato/farmacologia , Tamanho da Partícula , Ratos , Ratos WistarRESUMO
We previously reported that Indian paediatric patients with atypical haemolytic-uraemic syndrome (aHUS) showed high frequencies of anti-complement factor H (FH) autoantibodies that are correlated with homozygous deletion of the genes for FH-related proteins 1 and 3 (FHR1 and FHR3) (FHR1/3-/- ). We now report that Indian paediatric aHUS patients without anti-FH autoantibodies also showed modestly higher frequencies of the FHR1/3-/- genotype. Further, when we characterized epitope specificities and binding avidities of anti-FH autoantibodies in aHUS patients, most anti-FH autoantibodies were directed towards the FH cell-surface anchoring polyanionic binding site-containing C-terminal short conservative regions (SCRs) 17-20 with higher binding avidities than for native FH. FH SCR17-20-binding anti-FH autoantibodies also bound the other cell-surface anchoring polyanionic binding site-containing region FH SCR5-8, at lower binding avidities. Anti-FH autoantibody avidities correlated with antibody titres. These anti-FH autoantibody characteristics did not differ between aHUS patients with or without the FHR1/3-/- genotype. Our data suggest a complex matrix of interactions between FHR1-FHR3 deletion, immunomodulation and anti-FH autoantibodies in the aetiopathogenesis of aHUS.
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Objectives: Although carbapenem susceptibility testing has been recommended for all Enterobacteriaceae from clinical specimens, for practical reasons a carbapenem is not included in many primary antibiotic panels for urine specimens. The 'iCREST' study sought carbapenemase-producing Enterobacteriaceae (CPE) in routine urine specimens yielding Gram-negative growth in five diagnostic laboratories in the UK. We sought also to compare locally and centrally determined MICs of meropenem and ceftazidime/avibactam. Methods: Positive growth from up to 2000 urine specimens per laboratory was plated onto chromID® CARBA SMART agar. Suspected CPE colonies were tested locally by Etest for susceptibility to meropenem and ceftazidime/avibactam, and referred to central laboratories for PCR confirmation of CPE status and microbroth MIC determination. Results: Twenty-two suspected CPE were identified from 7504 urine specimens. Ten were confirmed by PCR to have NDM (5), IMP (2), KPC (2) or OXA-48-like (1) carbapenemases. Locally determined ceftazidime/avibactam MICs showed complete categorical agreement with those determined centrally by microbroth methodology. The seven ceftazidime/avibactam-resistant isolates (MICs ≥256 mg/L) had NDM or IMP metallo-carbapenemases. Conclusions: The frequency of confirmed CPE among Gram-negative urinary isolates was low, at 0.13% (10/7504), but CPE were found in urines at all five participating sites and the diversity of carbapenemase genes detected reflected the complex epidemiology of CPE in the UK. These data can inform local policies about the cost-effectiveness and clinical value of testing Gram-negative bacteria from urine specimens routinely against a carbapenem as part of patient management and/or infection prevention and control strategies.
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Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/urina , Vigilância de Evento Sentinela , Adolescente , Adulto , Idoso , Antibacterianos/farmacologia , Proteínas de Bactérias , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Carbapenêmicos/farmacologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , Reino Unido/epidemiologia , Adulto Jovem , beta-LactamasesRESUMO
PURPOSE: The present investigation was aimed at developing Teriflunomide (TEF) and Methotrexate (MTX) loaded hydroxyapatite nanoparticles and increasing tolerability towards combination therapy against rheumatoid arthritis by reducing hepatotoxicity. METHODS: Drug-loaded HAp-NPs were synthesized by wet-chemical precipitation method and optimized by Box-Behnken experimental design. The developed NPs were subjected to in vitro and in vivo characterization. In-vivo pharmacodynamics and biochemical studies were performed on adjuvant- induced arthritis model treated with different formulations; MTX-TEF-SOL, TEF-HAp-NP, MTX-HAp-NP, TEF-MTX-HAp-NP, FOLITRAX-10 and AUBAGIO. RESULTS: The size of the optimized formulations, TEF-HAp-NP and MTX-HAp-NP, was found to be 224.3 ± 83.80 nm and 268.3 ± 73.86 nm with drug loading 53.11 ± 0.84% and 67.04 ± 1.12% respectively. In vitro release of TEF from TEF-HAp-NP (70.41 ± 1.22%) and MTX from MTX-HAp-NP (82.43 ± 1.31%) up to 24 h revealed sustained release pattern. Results of the arthritic assessment study showed a significant (P < 0.05) reduction in ankle diameter (61.30 ± 7.42) and arthritis score (2.35 ± 0.24) with a marked restoration of ankle joint micro-architecture in TEF-MTX-HAp-NP treated group. During Hepatotoxicity studies, liver histopathology revealed that the formulation MTX-TEF-HAp-NP was least hepatotoxic with less hepatocyte swelling and fibrous connective tissue proliferation while Folitrax-10 was found to be most hepatotoxic. Biochemical studies revealed that Folitrax-10 significantly (P < 0.05) increased the GOT (313.64 ± 16) and GPT level (334.46 ± 13) while insignificant (P > 0.05) change in GOT (263.68 ± 17) and GPT (229.38 ± 10) level was recorded with TEF-MTX-HAp-NP. CONCLUSIONS: We report that the subcutaneous delivery of TEF-MTX-HAp-NP was most effective as it successfully reduced the dosage by half for maximizing therapeutic efficacy and minimizing side effects. Graphical Abstract á .
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Antirreumáticos/administração & dosagem , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Crotonatos/administração & dosagem , Durapatita/química , Metotrexato/administração & dosagem , Nanopartículas/química , Toluidinas/administração & dosagem , Animais , Antirreumáticos/farmacocinética , Antirreumáticos/farmacologia , Artrite Experimental/patologia , Artrite Reumatoide/patologia , Crotonatos/farmacocinética , Crotonatos/farmacologia , Portadores de Fármacos , Combinação de Medicamentos , Composição de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Feminino , Concentração de Íons de Hidrogênio , Hidroxibutiratos , Cinética , Metotrexato/farmacocinética , Metotrexato/farmacologia , Nitrilas , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Ratos , Ratos Wistar , Distribuição Tecidual , Toluidinas/farmacocinética , Toluidinas/farmacologiaRESUMO
L-Tyrosine which is one of the terminal metabolites of highly regulated aromatic amino-acid biosynthesis pathway in Escherichia coli is a precursor for synthesis of L-Dopa. In this study, we report over production of L-Dopa by enhancing expression of rate limiting isoenzyme of shikimate kinase (aroL), chorismate synthase (aroC), aromatic-amino-acid aminotransferase (tyrB) and 3-phosphoshikimate 1-carboxyvinyltransferase (aroA) form a plasmid module harboring five enzymes under two inducible promoters converting shikimate to tyrosine. 4-hydroxyphenylacetate-3-hydrolase (hpaBC) which converts L-Tyrosine to L-Dopa was expressed constitutively from a separate plasmid module. Feedback deregulated expression of 3-Deoxy-D-arabinoheptulosonate-7-phosphate (DAHP) synthase (aroG*) replacing wild type aroG under its natural promoter led to enhancement of L-Dopa production. Deletion of transcriptional repressor tyrR and links to other competing pathways improved titers of L-Dopa. We focused on having a balanced flux by constitutive expression of pathway enzymes from plasmid constructs rather than achieving higher amounts of catalytic protein by induction. We observed glycerol when used as a carbon source for the final strain led to low acid production. The best performing strain led to decoupling of acid production and product formation in bioreactor. Fed batch analysis of the final strain led to 12.5 g/L of L-Dopa produced in bioreactor.
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Escherichia coli , Genoma Bacteriano , Glicerol/metabolismo , Levodopa/biossíntese , Engenharia Metabólica , Microrganismos Geneticamente Modificados , Plasmídeos , Escherichia coli/genética , Escherichia coli/metabolismo , Levodopa/genética , Microrganismos Geneticamente Modificados/genética , Microrganismos Geneticamente Modificados/metabolismoRESUMO
PURPOSE: The study purposes to evaluate nanocrystalline biopolymeric nanoparticles encapsulating methotrexate and dexamethasone with high biocompatibility, enhanced therapeutic efficacy and reduced toxicity. METHODS: Chitosan nanoparticles were prepared by ionic gelation, and Methotrexate (MTX) and Dexamethasone (DEX) were loaded during the preparation and screened for their in vitro efficacy in HEK and RAW264.7 cells, ex vivo and in vivo efficacy. RESULTS: FTIR confirmed the involvement of phosphoric group of sTPP with amine groups of chitosan and also role of hydrogen bonding involved in the preparation of MTXCHNP and DEXCHNP. Controlled release patterns coupled with diffusion of drug were observed in two different buffers (PBS) at pH 7.4 and pH 5.8. The IC50 for MTXCHNP for HEK was 26.1 µg/ml and 7.7 µg/ml for RAW 264.7 cells. In DEXCHNP, the IC50 was 20.12 µg/ml for HEK and 7.37 µg/ml for RAW264.7 cells. Enhanced uptake of FITC-CHNP by RAW cells indicated internalization of nanoparticles by phagocytosis. The enhanced release of drug at lower pH justified increased cytotoxicity. Negligible ex-vivo hemolysis indicated the higher biocompatibility of the nanoparticles. 99mTc-CHNP exhibited maximum absorption in blood circulation in 3 h, followed by hepatic metabolism and renal clearance. Higher in-vivo anti-arthritic activity and antioxidant activity was observed post-intraperitoneal (i.p.) injections by both MTXCHNP and DEXCHNP when compared to MTX (0.75 mg/Kg by i.p. route) and DEX (0.2 mg/Kg/i.p./daily) per se. CONCLUSION: The nanocrystalline biopolymeric nanoparticles were stable, biocompatible and have potential to be administered through i.p. route with minimal toxicity and high efficacy.
Assuntos
Antirreumáticos/administração & dosagem , Artrite Reumatoide/tratamento farmacológico , Quitosana/química , Dexametasona/administração & dosagem , Metotrexato/administração & dosagem , Nanopartículas/química , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/farmacologia , Antirreumáticos/química , Antirreumáticos/farmacologia , Materiais Biocompatíveis , Técnicas de Cultura de Células , Linhagem Celular , Dexametasona/química , Dexametasona/farmacologia , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Excipientes/química , Humanos , Concentração de Íons de Hidrogênio , Metotrexato/química , Metotrexato/farmacologia , Tamanho da Partícula , Ratos Wistar , Propriedades de Superfície , Distribuição TecidualRESUMO
As pediatric liver transplantation comes of age, experts gathered to discuss current paradigms and define gaps in knowledge warranting research to further improve patient and graft outcomes. Identified areas ripe for collaborative research include understanding the molecular and cellular mechanisms of tolerance and the role of donor-specific antibodies, considering ways to expand donor pool, minimizing long-term side effects of immunosuppression, and fine-tuning surgical techniques to minimize biliary and vascular complications.