RESUMEN
PURPOSE: The use of laparoscopy for paediatric inguinal hernia repairs has increased significantly over the past 2 decades. However, there is significant variation in the reported recurrence rates in the literature, with many studies reporting higher rates than the open operation. This may be explained by the range of different techniques currently included under the term laparoscopic inguinal hernia repair. The purpose of this study is to determine whether dividing the hernia sac before ligation improves surgical outcomes following a paediatric laparoscopic inguinal hernia repair compared to ligation alone. METHODS: A systematic review of the literature was performed following PRISMA guidelines of all studies reporting the outcomes following paediatric laparoscopic inguinal hernia repair where the technique was recorded as laparoscopic suture ligation alone (LS) or laparoscopic sac division and suture ligation (LSDS). Studies were assessed for risk of bias and exclusion criteria included reported follow-up of less than 6 months. RESULTS: A total of 8518 LS repairs and 6272 LSDS repairs were included in the final analysis. LSDS repair was associated with a significantly lower recurrence rate (odds ratio 0.51, 95% CI 0.36-0.71, p = 0.001). There was no significant difference in the rates of testicular ascent or atrophy. CONCLUSION: Recreating the open operation by hernia sac division followed by suture ligation significantly reduces the risk of hernia recurrence.
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Hernia Inguinal , Laparoscopía , Niño , Humanos , Hernia Inguinal/cirugía , Herniorrafia/efectos adversos , Herniorrafia/métodos , Resultado del Tratamiento , Estudios Retrospectivos , Recurrencia , Laparoscopía/efectos adversos , Laparoscopía/métodosRESUMEN
BACKGROUND: Recent evidence suggests simple laparoscopic inguinal herniorrhaphy is associated with higher rates of recurrence and testicular ascent. We instigated a standardised approach to laparoscopic inguinal herniotomy (LIH), with circumferential sac division and 'purse-string' closure (4/0 monofilament polypropylene). An active follow-up programme was pursued. We reviewed our outcomes of this technique and compared them to an open herniotomy (OIH) cohort. METHODS: LIH patients were identified prospectively (2017-2021): OIH retrospectively from 2016. Risk factors for complications were defined: extremely to very preterm (< 32 weeks), emergency presentation with incarceration, and redo surgery for recurrence. Data are presented as median [IQR]. Comparisons used Fisher's exact and Mann-Whitney U tests: significance defined as p < 0.05. RESULTS: 192 inguinal herniae in 140 patients were included in the LIH group and 214 herniae in 179 patients in the OIH group. Groups were similar in age and gender. The LIH group had a significantly larger proportion of cases that were premature, had emergency surgery, or had redo surgery after previous OIH. Follow-up was 24.4 months [10.8-33.6] vs. 66.4 [64.5-68.5] (LIH vs. OIH). Hernia recurrence occurred in 2/192 (1.0%) vs. 4/214 (1.9%) (LIH vs. OIH), p = 0.69. There was one known case of testicular ascent after OIH but none in the LIH group. CONCLUSIONS: Recreation of the open herniotomy laparoscopically appears to confer excellent outcomes, with low rates of recurrence despite a high proportion of patients having known risk factors. Further long-term data on rates of testicular ascent after active follow-up are required.
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Hernia Inguinal , Laparoscopía , Hernia Inguinal/cirugía , Herniorrafia , Humanos , Lactante , Recién Nacido , Masculino , Recurrencia , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: Gastrostomy insertion is a common procedure for paediatric surgeons, with the percutaneous endoscopic gastrostomy (PEG) technique long favoured for its simplicity and speed. However, there is growing evidence to suggest that primary laparoscopic balloon gastrostomy (LBG) insertions may have lower complication rates. This study aimed to determine the relative safety and healthcare resource burden of PEG and LBG. METHODS: A retrospective review of all primary gastrostomy insertions (2011-2019). Primary outcome measures included return to theatre for emergency laparotomy and healthcare burden (total gastrostomy-related admissions, length of stay and total theatre utilisation). RESULTS: 338 PEGs and 277 LBGs were inserted with a minimum follow-up period of six months. Following PEG insertion 12/338(3.6%) children required an emergency laparotomy for gastrostomy-related complications. This compared to 2/277(0.7%) following LBG insertion (ARR2.8% (95%CI0.6-5.0), p < 0.0267). When considering all gastrostomy related admissions, there was no significant difference in total theatre utilisation (PEG = 85 [IQR58-117] minutes, LBG = 86 [IQR75-105] minutes, p = 0.12). However, PEGs were found to have an overall longer length of stay 4 [IQR3-7] vs 3 [IQR2-4] days. CONCLUSIONS: LBGs carry a significantly lower rate of major complications and are not associated with an increased healthcare burden. LBG should be considered as the first line method of gastrostomy insertion in children.
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Laparoscopía , Cirujanos , Niño , Gastrostomía , Humanos , Laparotomía , Complicaciones Posoperatorias/epidemiología , Estudios RetrospectivosRESUMEN
Interaction of factor VIII (FVIII) with von Willebrand factor (VWF) is mediated by the VWF D'D3 domains and thrombin-mediated release is essential for hemostasis after vascular injury. VWF-D'D3 mutations resulting in loss of FVIII binding are the underlying cause of von Willebrand disease (VWD) type 2N. Furthermore, the FVIII-VWF interaction has significant implications for the development of therapeutics for bleeding disorders, particularly hemophilia A, in which endogenous VWF clearance imposes a half-life ceiling on replacement FVIII therapy. To understand the structural basis of FVIII engagement by VWF, we solved the structure of BIVV001 by cryo-electron microscopy to 2.9 Å resolution. BIVV001 is a bioengineered clinical-stage FVIII molecule for the treatment of hemophilia A. In BIVV001, VWF-D'D3 is covalently linked to an Fc domain of a B domain-deleted recombinant FVIII (rFVIII) Fc fusion protein, resulting in a stabilized rFVIII/VWF-D'D3 complex. Our rFVIII/VWF structure resolves BIVV001 architecture and provides a detailed spatial understanding of previous biochemical and clinical observations related to FVIII-VWF engagement. Notably, the FVIII acidic a3 peptide region (FVIII-a3), established as a critical determinant of FVIII/VWF complex formation, inserts into a basic groove formed at the VWF-D'/rFVIII interface. Our structure shows direct interaction of sulfated Y1680 in FVIII-a3 and VWF-R816 that, when mutated, leads to severe hemophilia A or VWD type 2N, respectively. These results provide insight on this key coagulation complex, explain the structural basis of many hemophilia A and VWD type 2N mutations, and inform studies to further elucidate how VWF dissociates rapidly from FVIII upon activation.
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Microscopía por Crioelectrón/métodos , Factor VIII/química , Proteínas Recombinantes de Fusión/química , Factor de von Willebrand/química , Combinación de Medicamentos , Humanos , Modelos Moleculares , Conformación Proteica , Dominios Proteicos , Mapeo de Interacción de Proteínas , Proteínas Recombinantes de Fusión/ultraestructuraRESUMEN
D assemblies make up half of the von Willebrand factor (VWF), yet are of unknown structure. D1 and D2 in the prodomain and D'D3 in mature VWF at Golgi pH form helical VWF tubules in Weibel Palade bodies and template dimerization of D3 through disulfides to form ultralong VWF concatemers. D'D3 forms the binding site for factor VIII. The crystal structure of monomeric D'D3 with cysteine residues required for dimerization mutated to alanine was determined at an endoplasmic reticulum (ER)-like pH. The smaller C8-3, TIL3 (trypsin inhibitor-like 3), and E3 modules pack through specific interfaces as they wind around the larger, N-terminal, Ca2+-binding von Willebrand D domain (VWD) 3 module to form a wedge shape. D' with its TIL' and E' modules projects away from D3. The 2 mutated cysteines implicated in D3 dimerization are buried, providing a mechanism for protecting them against premature disulfide linkage in the ER, where intrachain disulfide linkages are formed. D3 dimerization requires co-association with D1 and D2, Ca2+, and Golgi-like acidic pH. Associated structural rearrangements in the C8-3 and TIL3 modules are required to expose cysteine residues for disulfide linkage. Our structure provides insight into many von Willebrand disease mutations, including those that diminish factor VIII binding, which suggest that factor VIII binds not only to the N-terminal TIL' domain of D' distal from D3 but also extends across 1 side of D3. The organizing principle for the D3 assembly has implications for other D assemblies and the construction of higher-order, disulfide-linked assemblies in the Golgi in both VWF and mucins.
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Factor VIII/metabolismo , Multimerización de Proteína , Factor de von Willebrand/química , Sitios de Unión , Cristalografía por Rayos X , Disulfuros , Retículo Endoplásmico/química , Aparato de Golgi/química , Humanos , Concentración de Iones de Hidrógeno , Espectroscopía de Resonancia Magnética , Biogénesis de Organelos , Unión Proteica , Dominios Proteicos , Factor de von Willebrand/metabolismoRESUMEN
The main complication of replacement therapy with factor in hemophilia A (HemA) is the formation of inhibitors (neutralizing anti-factor VIII [FVIII] antibodies) in â¼30% of severe HemA patients. Because these inhibitors render replacement FVIII treatment essentially ineffective, preventing or eliminating them is of top priority in disease management. The extended half-life recombinant FVIII Fc fusion protein (rFVIIIFc) is an approved therapy for HemA patients. In addition, it has been reported that rFVIIIFc may induce tolerance to FVIII more readily than FVIII alone in HemA patients that have developed inhibitors. Given that the immunoglobulin G1 Fc region has the potential to interact with immune cells expressing Fc receptors (FcRs) and thereby affect the immune response to rFVIII, we investigated how human macrophages, expressing both FcRs and receptors reported to bind FVIII, respond to rFVIIIFc. We show herein that rFVIIIFc, but not rFVIII, uniquely skews macrophages toward an alternatively activated regulatory phenotype. rFVIIIFc initiates signaling events that result in morphological changes, as well as a specific gene expression and metabolic profile that is characteristic of the regulatory type Mox/M2-like macrophages. Further, these changes are dependent on rFVIIIFc-FcR interactions. Our findings elucidate mechanisms of potential immunomodulatory properties of rFVIIIFc.
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Factor VIII/farmacología , Fragmentos Fc de Inmunoglobulinas/farmacología , Activación de Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Proteínas Recombinantes de Fusión/farmacología , Células Cultivadas , Factor VIII/uso terapéutico , Regulación de la Expresión Génica/efectos de los fármacos , Hemofilia A/tratamiento farmacológico , Hemofilia A/patología , Humanos , Fragmentos Fc de Inmunoglobulinas/uso terapéutico , Leucocitos Mononucleares/citología , Macrófagos/citología , Macrófagos/efectos de los fármacos , Receptores Fc/metabolismo , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/uso terapéutico , Transducción de Señal/efectos de los fármacosRESUMEN
AIM OF STUDY: The aim of this study was to evaluate management of children with an anterior midline neck swelling by establishing 1) whether a preoperative ultrasound scan (USS) was appropriately requested, performed and reported; 2) whether there was preoperative infection; 3) whether a Sistrunk procedure was performed; 4) the rate of thyroglossal duct cyst (TGDC) recurrence following simple excision vs. Sistrunk procedure. METHODS: A single centre retrospective study of children who underwent surgery for anterior midline neck swelling between April 2000 and May 2015 at our institution was performed. These were identified using a clinical coding system, and data were collected from electronic medical records, radiology, and histopathology reports. Recurrence rates between simple excision and Sistrunk groups were compared using Chi-square test. MAIN RESULTS: 227 patients were identified (115 male, 112 female). 169 (74%) had a preoperative USS. The presence of a thyroid gland was stated in 79% of USS reports. This increased to 92% when the requesting surgeon had specifically asked about this. 48 (21%) patients underwent simple excision, while 175 (77%) had a Sistrunk procedure. Recurrence was significantly more likely following simple excision than a Sistrunk procedure (29% vs 6.9%; P<0.0001). Of 25 TGDC recurrences, 9 (36%) had an inconclusive or alternative histopathological diagnosis at first operation. CONCLUSION: Preoperative USS should be performed in all patients with an anterior midline neck swelling. Appropriate requesting increases likelihood of a report confirming (or otherwise) the presence of a thyroid gland. A Sistrunk procedure is the operation of choice in all children presenting with an anterior midline neck swelling. The surgeon cannot reliably differentiate a TGDC from alternative pathology intraoperatively. LEVEL OF EVIDENCE: Treatment study: level IV.
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Pautas de la Práctica en Medicina/estadística & datos numéricos , Quiste Tirogloso/diagnóstico por imagen , Quiste Tirogloso/cirugía , Niño , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Recurrencia , Estudios Retrospectivos , Quiste Tirogloso/complicaciones , UltrasonografíaRESUMEN
BACKGROUND: Several classification systems exist to predict mortality in oesophageal atresia, the most widely quoted of these being over 20 years old. No classification system exists to predict morbidity. We sought to test whether these classification systems remain relevant and to determine whether they can be useful to predict morbidity. In addition, we aimed to identify independent risk factors for predicting mortality and morbidity. METHODS: Neonates presenting with oesophageal atresia over a 20-year period (1990-2010) were retrospectively reviewed. Discriminative statistical analysis compared the performance of current classification systems. Stepwise logistic regression analysis of the influence of perioperative risk factors on mortality and duration of ventilatory support and intensive care unit stay were performed. RESULTS: All classification systems predicted mortality in this series of 248 neonates. Birth weight, cardiac anomalies and pre-operative pneumonia were independent risk factors for predicting mortality in oesophageal atresia. The Waterston classification is the most useful classification for predicting post-operative morbidity in terms of length of hospital stay and time spent ventilated. CONCLUSION: Despite advances in the neonatal care of the very low birth weight infant and those with congenital cardiac disease, these conditions remain relevant in predicting mortality and morbidity in oesophageal atresia.
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Atresia Esofágica/mortalidad , Complicaciones Posoperatorias , Peso al Nacer , Análisis Discriminante , Atresia Esofágica/clasificación , Atresia Esofágica/cirugía , Femenino , Cardiopatías Congénitas/complicaciones , Humanos , Lactante , Recién Nacido , Recién Nacido de muy Bajo Peso , Modelos Logísticos , Masculino , Neumonía/complicaciones , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Reino Unido/epidemiologíaRESUMEN
: The aim of this study was to compare the hemostatic efficacy of recombinant factor VIII Fc (rFVIIIFc) (Eloctate) and Advate by ex-vivo rotation thromboelastometry (ROTEM) of whole blood and to explore potential ROTEM parameters that may be more predictive of a patient's bleeding tendency than plasma FVIII activity. Thirteen clinical sites were selected to perform ROTEM on freshly collected blood samples from 44 patients in the phase 3 study for rFVIIIFc, including 16 patients undergoing sequential pharmacokinetic assessment of Advate and rFVIIIFc. Equivalent hemostatic activity was observed for rFVIIIFc and Advate in postinfusion samples, followed by improvements for rFVIIIFc in clotting time, clot formation time and alpha angle (α) for a longer duration than Advate, consistent with the pharmacokinetic improvements reported previously for rFVIIIFc. Our study did not demonstrate a statistical correlation between a patient's ROTEM activity at baseline or at trough and the occurrence of spontaneous bleeds while on prophylactic therapy. However, an association was observed between postinfusion clotting time and the occurrence of one or more spontaneous bleeds vs. no bleeds over a follow-up period of 1 year (Pâ=â0.003). How well a patient's whole blood clotting deficiency is corrected after a dose of FVIII may be an indicator of subsequent bleeding tendency in patients with otherwise equivalent FVIII peak and trough levels. The technical challenges of standardizing the ROTEM, largely overcome in the current study, may however preclude the use of this method for widespread assessment of global hemostasis unless additional assay controls or normalization procedures prove to be effective.
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Factor VIII/metabolismo , Fragmentos Fc de Inmunoglobulinas/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Tromboelastografía/métodos , Femenino , Humanos , Masculino , FenotipoRESUMEN
INTRODUCTION: Hemophilia B is an inherited X chromosome-linked disorder characterized by impaired blood clotting owing to the absence of functional coagulation factor IX. Due to the relatively short half-life of factor IX, patients with hemophilia B require frequent factor IX infusions to maintain prophylaxis. We have developed a recombinant factor IX (rFIX) fused to the Fc region of IgG (rFIXFc) with an extended half-life in animals and humans. MATERIALS AND METHODS: Procoagulant properties of rFIXFc and rFIX (BENEFIX®) were compared to determine the effect of the Fc region on rFIXFc hemostatic function. Specifically, we assessed rFIXFc activation, intermolecular interactions within the Xase complex, inactivation by antithrombin III (AT) and thrombin generation potential compared with rFIX. We also assessed the acute and prophylactic efficacy profiles of rFIXFc and rFIX in vivo in hemophilia B mouse bleeding models. RESULTS AND CONCLUSIONS: The activation by factor XIa or factor VIIa/tissue factor, inhibition by AT, interaction profiles with phospholipids, affinities for factor VIIIa within the context of the Xase complex, and thrombin generation profiles were similar for rFIXFc and rFIX. Xase complexes formed with either molecule exhibited similar kinetic profiles for factor Xa generation. In acute efficacy models, mice infused with rFIXFc or rFIX were equally protected from bleeding. However, in prophylactic efficacy models, protection from bleeding was maintained approximately three times longer in rFIXFc-dosed mice than in those given rFIX; this prolonged efficacy correlates with the previously observed half-life extension. We conclude that rFIXFc retains critical FIX procoagulant attributes and that the extension in rFIXFc half-life translates into prolonged efficacy in hemophilia B mice.
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Coagulación Sanguínea/efectos de los fármacos , Coagulantes/farmacología , Factor IX/farmacología , Hemofilia B/tratamiento farmacológico , Hemorragia/tratamiento farmacológico , Fragmentos Fc de Inmunoglobulinas/farmacología , Proteínas Recombinantes de Fusión/farmacología , Animales , Antitrombina III/farmacología , Pruebas de Coagulación Sanguínea , Modelos Animales de Enfermedad , Activación Enzimática/fisiología , Factor IX/genética , Factor VIIa/farmacología , Factor XIa/farmacología , Semivida , Fragmentos Fc de Inmunoglobulinas/genética , Ratones , Ratones Endogámicos C57BL , Proteínas Recombinantes de Fusión/genética , Trombina/biosíntesisRESUMEN
XTEN™ is a class of unstructured hydrophilic, biodegradable protein polymers designed to increase the half-lives of therapeutic peptides and proteins. XTEN polymers and XTEN fusion proteins are typically expressed in Escherichia coli and purified by conventional protein chromatography as monodisperse polypeptides of exact length and sequence. Unstructured XTEN polypeptides have hydrodynamic volumes significantly larger than typical globular proteins of similar mass, thus imparting a bulking effect to the therapeutic payloads attached to them. Since their invention, XTEN polypeptides have been utilized to extend the half-lives of a variety of peptide- and protein-based therapeutics. Multiple clinical and preclinical studies and related drug discovery and development efforts are in progress. This review details the most current understanding of physicochemical properties and biological behavior of XTEN and XTENylated molecules. Additionally, the development path and status of several advanced drug discovery and development efforts are highlighted.
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Productos Biológicos/farmacocinética , Descubrimiento de Drogas/métodos , Polímeros/farmacocinética , Proteínas/farmacocinética , Animales , Productos Biológicos/química , Ensayos Clínicos como Asunto/métodos , Descubrimiento de Drogas/tendencias , Semivida , Humanos , Polímeros/química , Estructura Secundaria de Proteína , Proteínas/químicaRESUMEN
Association with the D'D3 domain of von Willebrand factor (VWF) stabilizes factor VIII (FVIII) in the circulation and maintains it at a level sufficient to prevent spontaneous bleeding. We used negative-stain electron microscopy (EM) to visualize complexes of FVIII with dimeric and monomeric forms of the D'D3 domain. The EM averages show that FVIII interacts with the D'D3 domain primarily through its C1 domain, with the C2 domain providing a secondary attachment site. Hydrogen-deuterium exchange mass spectrometry corroborated the importance of the C1 domain in D'D3 binding and implicates additional surface regions on FVIII in the interaction. Together, our results establish that the C1 domain is the major binding site on FVIII for VWF, reiterate the importance of the a3 acidic peptide in VWF binding, and suggest that the A3 and C2 domains play ancillary roles in this interaction.
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Factor VIII/química , Factor VIII/metabolismo , Factor de von Willebrand/química , Factor de von Willebrand/metabolismo , Sitios de Unión , Factor VIII/ultraestructura , Células HEK293 , Humanos , Espectrometría de Masas , Microscopía Electrónica , Estructura Terciaria de Proteína , Factor de von Willebrand/ultraestructuraRESUMEN
Nearly 350 IgG-based therapeutics are approved for clinical use or are under development for many diseases lacking adequate treatment options. These include molecularly engineered biologicals comprising the IgG Fc-domain fused to various effector molecules (so-called Fc-fusion proteins) that confer the advantages of IgG, including binding to the neonatal Fc receptor (FcRn) to facilitate in vivo stability, and the therapeutic benefit of the specific effector functions. Advances in IgG structure-function relationships and an understanding of FcRn biology have provided therapeutic opportunities for previously unapproachable diseases. This article discusses approved Fc-fusion therapeutics, novel Fc-fusion proteins and FcRn-dependent delivery approaches in development, and how engineering of the FcRn-Fc interaction can generate longer-lasting and more effective therapeutics.
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Antígenos de Histocompatibilidad Clase I , Inmunoglobulina G , Inmunoterapia , Receptores Fc , Proteínas Recombinantes de Fusión , Animales , Humanos , Ratones , Modelos MolecularesRESUMEN
Recombinant factor VIII Fc (rFVIIIFc) is a fusion protein consisting of a single B-domain-deleted (BDD) FVIII linked recombinantly to the Fc domain of human IgG1 to extend half-life. To determine if rFVIIIFc could be further improved by maintaining the heavy and light chains within a contiguous single chain (SC), we evaluated the activity and function of SC rFVIIIFc, an isoform that is not processed at residue R1648. SC rFVIIIFc showed equivalent activity in a chromogenic assay compared to rFVIIIFc, but approximately 40% activity by the one-stage clotting assay in the presence of von Willebrand Factor (VWF), with full activity in the absence of VWF. Moreover, SC rFVIIIFc demonstrated markedly delayed thrombin-mediated release from VWF, but an activity similar to that of rFVIIIFc upon activation in FXa generation assays. Therefore, the apparent reduction in specific activity in the aPTT assay appears to be primarily due to delayed release of FVIII from VWF. To assess whether stability and activity of SC rFVIIIFc were affected in vivo, a tail vein transection model in Hemophilia A mice was utilized. The results demonstrated similar pharmacokinetic profiles and comparable efficacy for SC rFVIIIFc and rFVIIIFc. Thus, while the single chain configuration did not promote enhanced half-life, it reduced the rate of release of FVIII from VWF required for activation. This impaired release may underlie the observed reduction in the one-stage clotting assay, but does not appear to affect the physiological activity of SC rFVIIIFc.
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Factor VIII/genética , Factor VIII/farmacocinética , Hemofilia A/tratamiento farmacológico , Proteínas Recombinantes de Fusión/farmacocinética , Animales , Clonación Molecular/métodos , Modelos Animales de Enfermedad , Factor VIII/química , Factor VIII/uso terapéutico , Semivida , Hemofilia A/sangre , Hemorragia , Humanos , Técnicas In Vitro , Masculino , Ratones , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/uso terapéutico , Trombina/metabolismo , Factor de von Willebrand/metabolismoRESUMEN
Due to variability in the one-stage clotting assay, the performance of new factor IX (FIX) products should be assessed in this assay. The objective of this field study was to evaluate the accuracy of measuring recombinant FIX Fc fusion protein (rFIXFc) activity in clinical haemostasis laboratories using the one-stage clotting assay. Human haemophilic donor plasma was spiked with rFIXFc or BeneFIX® at 0.80, 0.20, or 0.05 IU/ml based on label potency. Laboratories tested blinded samples using their routine one-stage assay and in-house FIX plasma standard. The mean spike recoveries for BeneFIX (n=30 laboratories) were 121 %, 144 %, and 168 % of expected at nominal 0.80, 0.20, and 0.05 IU/ml concentrations, respectively. Corresponding rFIXFc spike recoveries were 88 %, 107 %, and 132 % of expected, respectively. All BeneFIX concentrations were consistently overestimated by most laboratories. rFIXFc activity was reagent-dependent; ellagic acid and silica gave higher values than kaolin, which underestimated rFIXFc. BeneFIX demonstrated significantly reduced chromogenic assay activity relative to one-stage assay results and nominal activity, while rFIXFc activity was close to nominal activity at three concentrations with better dilution linearity than the typical one-stage assay. In conclusion, laboratory- and reagent-specific assay variabilities were revealed, with progressively higher variability at lower FIX concentrations. Non-parallelism against the FIX plasma standard was observed in all one-stage assays with rFIXFc and BeneFIX, leading to significant overestimation of FIX activity at lower levels and generally high inter-laboratory variability. Compared to the accuracy currently achieved in clinical laboratories when measuring other rFIX products, most laboratories measured rFIXFc activity with acceptable accuracy and reliability using routine one-stage assay methods and commercially available plasma standards.
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Pruebas de Coagulación Sanguínea , Fragmentos Fc de Inmunoglobulinas/sangre , Ensayos de Aptitud de Laboratorios , Proteínas Recombinantes de Fusión/sangre , Calibración , Compuestos Cromogénicos , Monitoreo de Drogas , Factor IX , Hemofilia B/sangre , Humanos , Indicadores y Reactivos , Laboratorios , Estándares de Referencia , Reproducibilidad de los Resultados , Método Simple CiegoRESUMEN
BACKGROUND/PURPOSE: Total esophagogastric dissociation has been described as both a primary and a rescue procedure for patients with severe gastroesophageal reflux. Although most commonly used in the neurologically impaired, it has also been used in those with no neurological impairment. The main objective of this study was to determine morbidity and mortality for this procedure. METHODS: All published cases of esophagogastric dissociation in children were identified. Series were updated where possible by personal communication with the author. Patient characteristics, indications, morbidity, and mortality were analyzed. RESULTS: One hundred eighty-one cases were identified. One hundred seventeen were primary operations and 64 were rescue procedures. There were 29 (16.0%) early complications and 28 (15.5%) late complications with 6 (3.3%) deaths related to the procedure of a total of 35 deaths. Twenty-one patients (11.6%) required re-operation in the study periods. CONCLUSIONS: Esophagogastric dissociation has an acceptable morbidity and mortality. It is useful as both a primary and a rescue procedure.
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Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Esófago/cirugía , Reflujo Gastroesofágico/cirugía , Anastomosis en-Y de Roux , Procedimientos Quirúrgicos del Sistema Digestivo/mortalidad , Gastrostomía , Humanos , Morbilidad , Complicaciones Posoperatorias/mortalidadRESUMEN
The incidence of necrotizing pneumonia and empyema complicated by bronchopleural fistula is rising. We describe the case of a 2-year-old boy who presented with empyema thoracis and necrotizing pneumonia who developed a bronchopleural fistula. At initial thoracotomy for decortication, necrotic lung was found and resected. He subsequently underwent further thoracotomy, prolonged chest tube drainage and endobronchial glue application attempts to close a bronchopleural fistula. The fistula was only sealed at third thoracotomy and completion pneumonectomy. This case highlights the potential challenges faced when dealing with air leaks in the setting of infection and we discuss the treatment options available.
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Fístula Bronquial/cirugía , Empiema Pleural/complicaciones , Neumonectomía , Neumonía/complicaciones , Fístula Bronquial/etiología , Preescolar , Humanos , Masculino , Enfermedades Pleurales/etiología , Enfermedades Pleurales/cirugíaRESUMEN
Atrial natriuretic peptide (ANP) may be a useful molecule for the treatment of cardiovascular diseases due to its potent natriuretic effects. In an effort to prolong the short in vivo half-life of ANP, fusions of the peptide to the Fc domain of IgG were generated using a semisynthetic methodology. Synthetic ANP peptides were synthesized with thioesters at either the N- or C-termini of the peptide and subsequently linked to the N-terminus of recombinantly expressed Fc using native chemical ligation. The linker length between the ANP and Fc moieties was varied among 2, 11, or 16 amino acids. In addition, either one ("monomeric") or two ("dimeric") ANP peptides were linked to Fc to study whether this modification had an effect on in vitro activity and/or in vivo half-life. The various constructs were studied for in vitro activity using a cell-based cGMP assay. The ANP-Fc fusion constructs were between 16- and â¼375-fold weaker than unconjugated ANP in this assay, and a trend was observed where the most potent conjugates were those with longer linkers and in the dimeric configuration. The pharmacokinetics of several constructs were assessed in rats, and the half-life of the ANP-Fc's were found to be approximately 2 orders of magnitude longer than that of the unconjugated peptide. There was no significant difference in terminal half-life between the monomeric and dimeric constructs (2.8-5.5 h), but a trend was observed where the C(max) of the monomeric constructs was approximately 3-fold higher than that of the dimeric constructs, although the origin of this effect is not understood. These novel ANP-Fc fusion constructs hold promise for future therapeutic application in the treatment of cardiovascular diseases.
Asunto(s)
Factor Natriurético Atrial/farmacocinética , Fragmentos Fc de Inmunoglobulinas/química , Animales , Factor Natriurético Atrial/química , Línea Celular , Cromatografía en Gel , Ensayo de Inmunoadsorción Enzimática , Femenino , Semivida , Humanos , Técnicas In Vitro , Ratas , Ratas Wistar , Proteínas Recombinantes de Fusión/síntesis química , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/farmacocinéticaRESUMEN
Current factor IX (FIX) products display a half-life (t(1/2)) of â¼ 18 hours, requiring frequent intravenous infusions for prophylaxis and treatment in patients with hemophilia B. This open-label, dose-escalation trial in previously treated adult subjects with hemophilia B examined the safety and pharmacokinetics of rFIXFc. rFIXFc is a recombinant fusion protein composed of FIX and the Fc domain of human IgG(1), to extend circulating time. Fourteen subjects received a single dose of rFIXFc; 1 subject each received 1, 5, 12.5, or 25 IU/kg, and 5 subjects each received 50 or 100 IU/kg. rFIXFc was well tolerated, and most adverse events were mild or moderate in intensity. No inhibitors were detected in any subject. Dose-proportional increases in rFIXFc activity and Ag exposure were observed. With baseline subtraction, mean activity terminal t(1/2) and mean residence time for rFIXFc were 56.7 and 71.8 hours, respectively. This is â¼ 3-fold longer than that reported for current rFIX products. The incremental recovery of rFIXFc was 0.93 IU/dL per IU/kg, similar to plasma-derived FIX. These results show that rFIXFc may offer a viable therapeutic approach to achieve prolonged hemostatic protection and less frequent dosing in patients with hemophilia B. The trial was registered at www.clinicaltrials.gov as NCT00716716.
Asunto(s)
Factor IX/metabolismo , Hemofilia B/metabolismo , Hemofilia B/terapia , Proteínas Recombinantes de Fusión/uso terapéutico , Adolescente , Adulto , Anciano , Femenino , Semivida , Humanos , Masculino , Persona de Mediana Edad , Proteínas Recombinantes de Fusión/farmacocinética , Seguridad , Adulto JovenRESUMEN
Treatment of hemophilia B requires frequent infusions of factor IX (FIX) to prophylax against bleeding episodes. Hemophilia B management would benefit from a FIX protein with an extended half-life. A recombinant fusion protein (rFIXFc) containing a single FIX molecule attached to the Fc region of immunoglobulin G was administered intravenously and found to have an extended half-life, compared with recombinant FIX (rFIX) in normal mice, rats, monkeys, and FIX-deficient mice and dogs. Recombinant FIXFc protein concentration was determined in all species, and rFIXFc activity was measured in FIX-deficient animals. The half-life of rFIXFc was approximately 3- to 4-fold longer than that of rFIX in all species. In contrast, in mice in which the neonatal Fc receptor (FcRn) was deleted, the half-life of rFIXFc was similar to rFIX, confirming the increased circulatory time was due to protection of the rFIXFc via the Fc/FcRn interaction. Whole blood clotting time in FIX-deficient mice was corrected through 144 hours for rFIXFc, compared with 72 hours for rFIX; similar results were observed in FIX-deficient dogs. Taken together, these studies show the enhanced pharmacodynamic and pharmacokinetic properties of the rFIXFc fusion protein and provide the basis for evaluating rFIXFc in patients with hemophilia B.