RESUMEN
Cerebral venous thrombosis (CVT) is a rare venous thrombotic event. We review our local experience in the management of CVT in comparison to other venous thromboembolism (VTE) with specific focus on risk factors for thrombotic recurrence. Retrospective evaluation of consecutive CVT presentations from January 2005 to June 2015, at two major tertiary hospitals in Northeast Melbourne, Australia. This population was compared to a separate audit of 1003 consecutive patients with DVT and PE. Fifty-two patients (30 female, 22 male) with a median age of 40 (18-83) years, presented with 53 episodes of CVT. Twenty-nine episodes (55 %) were associated with an underlying risk factor, with hormonal risk factors in females being most common. The median duration of anticoagulation was 6 months with 11 receiving life-long anticoagulation. Eighty-one percent had residual thrombosis on repeat imaging, which was not associated with recurrence at the same or distant site. Nine (17 %) had CVT-related haemorrhagic transformation with two resultant CVT-related deaths (RR 22.5; p = 0.04). All three VTE recurrences occured in males with unprovoked events (RR 18.2; p = 0.05) who were subsequently diagnosed with myeloproliferative neoplasm (MPN). Compared to the non-cancer VTE population, non-cancer CVT patients were younger, had similar rate of provoked events and VTE recurrence, although with significantly higher rate of MPN diagnosis (RR 9.30 (2.29-37.76); p = 0.002) CVT is a rare thrombotic disorder. All recurrences in this audit occurred in male patients with unprovoked events and subsequent diagnosis of MPN, suggesting further evaluation for MPN may be warranted in patients with unprovoked CVT.
Asunto(s)
Trombosis Intracraneal/complicaciones , Trastornos Mieloproliferativos/etiología , Neoplasias/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Femenino , Humanos , Trombosis Intracraneal/diagnóstico , Trombosis Intracraneal/etiología , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Trombosis de la Vena/complicaciones , Trombosis de la Vena/diagnóstico , Trombosis de la Vena/etiología , Adulto JovenRESUMEN
OBJECTIVES: To determine the prevalence and correlates of antiphospholipid antibodies (APLA) in systemic sclerosis (SSc). METHODS: Nine hundred and forty SSc patients were tested for APLA using an ELISA assay at recruitment. Clinical manifestations were defined as present, if ever present from SSc diagnosis. Logistic regression analysis was used to determine the associations of APLA. RESULTS: One or more types of APLA were present in 226 (24.0%) patients. Anticardiolipin (ACA) IgG (ACA-IgG) antibodies were associated with right heart catheter-diagnosed pulmonary arterial hypertension (PAH), with higher titres corresponding with a higher likelihood of PAH (moderate titre (20-39 U/ml) ACA-IgG odds ratio [OR] 1.70, 95% CI: 1.01-2.93, p=0.047; high titre (>40 U/ml) ACA-IgG OR 4.60, 95% CI:1.02-20.8, p=0.047). Both ACA-IgM (OR 2.04, 95% CI: 1.4-3.0, p<0.0001) and ACA-IgG (OR 1.84, 95% CI: 1.2-2.8, p=0.005) were associated with interstitial lung disease (ILD). Increasing ACA-IgM and IgG titres were associated with increased likelihood of ILD. ACA-IgG was a marker of coexistent pulmonary hypertension and ILD (ILD-PH) (OR 2.10, 95% CI: 1.1-4.2, p=0.036). We also found an association between ACA-IgG and digital ulcers (OR 1.76, 95% CI: 1.16-2.67, p=0.008) and ACA-IgM and Raynaud's phenomenon (OR 2.39, 95% CI: 1.08-5.27, p=0.031). There was no association between APLA and SSc disease subtype, peak skin score, presence of other autoantibodies, mortality or other disease manifestations. CONCLUSIONS: The association of APLA with PAH, ILD, ILD-PH, Raynaud's phenomenon and digital ulcers suggests that endothelial abnormalities and small vessel thrombosis may be important in the pathogenesis of these disease features.
Asunto(s)
Anticuerpos Anticardiolipina/inmunología , Cardiopatías/inmunología , Hipertensión Pulmonar/inmunología , Enfermedades Pulmonares Intersticiales/inmunología , Esclerodermia Sistémica/inmunología , Anciano , Anticuerpos Antifosfolípidos/inmunología , Estudios de Cohortes , Femenino , Dermatosis de la Mano/etiología , Dermatosis de la Mano/inmunología , Cardiopatías/etiología , Humanos , Hipertensión Pulmonar/etiología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Modelos Logísticos , Enfermedades Pulmonares Intersticiales/etiología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad de Raynaud/etiología , Enfermedad de Raynaud/inmunología , Esclerodermia Sistémica/complicaciones , Úlcera Cutánea/etiología , Úlcera Cutánea/inmunologíaRESUMEN
A working group of clinicians and scientists was formed to review the clinical considerations for use of low-molecular-weight heparin (LMWH) biosimilars. LMWH are biological molecules of significant complexity; the full complexity of chemical structure is still to be elucidated. LMWH biosimilars are products that are biologically similar to their reference product and rely on clinical data from a reference product to establish safety and efficacy. The complex nature of LMWH molecules means that it is uncertain whether a LMWH biosimilar is chemically identical to its reference product; this introduces the possibility of differences in activity and immunogenicity. The challenge for regulators and clinicians is to evaluate the level of evidence required to demonstrate that a LMWH is sufficiently similar to the reference product. The consensus opinion of the working group is that prior to clinical use a LMWH biosimilar should have proven efficacy and safety, similar to the reference product with prospective studies, which should be confirmed with a proactive post-marketing pharmacovigilance programme.
Asunto(s)
Anticoagulantes/uso terapéutico , Biosimilares Farmacéuticos/uso terapéutico , Heparina de Bajo-Peso-Molecular/uso terapéutico , Sistemas de Registro de Reacción Adversa a Medicamentos , Anticoagulantes/efectos adversos , Anticoagulantes/química , Anticoagulantes/clasificación , Anticoagulantes/farmacocinética , Australia , Biosimilares Farmacéuticos/efectos adversos , Biosimilares Farmacéuticos/química , Biosimilares Farmacéuticos/farmacocinética , Biotecnología , Método Doble Ciego , Aprobación de Drogas , Industria Farmacéutica , Sustitución de Medicamentos , Agencias Gubernamentales/normas , Heparina de Bajo-Peso-Molecular/efectos adversos , Heparina de Bajo-Peso-Molecular/química , Heparina de Bajo-Peso-Molecular/clasificación , Heparina de Bajo-Peso-Molecular/farmacocinética , Humanos , Estructura Molecular , Peso Molecular , Ensayos Clínicos Controlados Aleatorios como Asunto , Relación Estructura-Actividad , Equivalencia Terapéutica , Estados Unidos , United States Food and Drug Administration/normasRESUMEN
BACKGROUND: Fatigue is a common symptom in patients with advanced malignancy, and has been associated with both physiological and psychological factors in patients with solid tumours. AIM: This study sought to explore the predictors of fatigue in a population with haematological malignancy. METHODS: Consecutive outpatients and inpatients attending a haematology centre completed the Memorial Symptom Assessment Scale, and clinical, treatment and demographic information were noted. RESULTS: Of 180 patients, fatigue was present in 69%, and causing considerable distress in 26%. Univariate analysis revealed fatigue was associated with poor performance status, low haemoglobin, feeling sad, worried, irritable and nervous. Multivariate modeling revealed that those factors predictive of fatigue were poor performance status, having active disease, feeling sad and irritable, while haemoglobin level was not predictive of fatigue. CONCLUSIONS: Fatigue is a multidimensional symptom in patients with haematological malignancy whose presence must prompt a holistic assessment of potential contributors that goes beyond correction of haemoglobin levels.
Asunto(s)
Ansiedad/epidemiología , Depresión/epidemiología , Fatiga/epidemiología , Leucemia/epidemiología , Linfoma/epidemiología , Dolor/epidemiología , Calidad de Vida/psicología , Adulto , Anciano , Anciano de 80 o más Años , Ansiedad/etiología , Ansiedad/psicología , Fatiga/etiología , Fatiga/psicología , Humanos , Leucemia/complicaciones , Leucemia/psicología , Linfoma/complicaciones , Linfoma/psicología , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prevalencia , Factores de Riesgo , Índice de Severidad de la Enfermedad , Estrés PsicológicoRESUMEN
New oral anticoagulants (NOAC) are becoming available as alternatives to warfarin to prevent systemic embolism in patients with non-valvular atrial fibrillation and for the treatment and prevention of venous thromboembolism. An in-depth understanding of their pharmacology is invaluable for appropriate prescription and optimal management of patients receiving these drugs should unexpected complications (such as bleeding) occur, or the patient requires urgent surgery. The Australasian Society of Thrombosis and Haemostasis has set out to inform physicians on the use of the different NOAC based on current available evidence focusing on: (i) selection of the most suitable patient groups to receive NOAC, (ii) laboratory measurements of NOAC in appropriate circumstances and (iii) management of patients taking NOAC in the perioperative period, and strategies to manage bleeding complications or 'reverse' the anticoagulant effects for urgent invasive procedures.
Asunto(s)
Anticoagulantes/uso terapéutico , Bencimidazoles/uso terapéutico , Morfolinas/uso terapéutico , Pirazoles/uso terapéutico , Piridonas/uso terapéutico , Tiofenos/uso terapéutico , Trombofilia/tratamiento farmacológico , beta-Alanina/análogos & derivados , Administración Oral , Anticoagulantes/administración & dosificación , Anticoagulantes/efectos adversos , Anticoagulantes/farmacocinética , Fibrilación Atrial/complicaciones , Bencimidazoles/administración & dosificación , Bencimidazoles/efectos adversos , Bencimidazoles/farmacocinética , Pruebas de Coagulación Sanguínea , Pérdida de Sangre Quirúrgica/prevención & control , Contraindicaciones , Dabigatrán , Interacciones Farmacológicas , Monitoreo de Drogas , Sustitución de Medicamentos , Procedimientos Quirúrgicos Electivos , Urgencias Médicas , Hematoma Espinal Epidural/inducido químicamente , Hematoma Espinal Epidural/prevención & control , Hemorragia/inducido químicamente , Hemorragia/prevención & control , Hemorragia/terapia , Humanos , Enfermedades Renales/metabolismo , Hepatopatías/metabolismo , Morfolinas/administración & dosificación , Morfolinas/efectos adversos , Morfolinas/farmacocinética , Selección de Paciente , Pirazoles/administración & dosificación , Pirazoles/efectos adversos , Piridonas/administración & dosificación , Piridonas/efectos adversos , Rivaroxabán , Accidente Cerebrovascular/complicaciones , Tiofenos/administración & dosificación , Tiofenos/efectos adversos , Tiofenos/farmacocinética , Trombofilia/etiología , beta-Alanina/administración & dosificación , beta-Alanina/efectos adversos , beta-Alanina/farmacocinética , beta-Alanina/uso terapéuticoRESUMEN
BACKGROUND: Inferior vena cava (IVC) filters are increasingly used to treat venous thromboembolism when there are contraindications or failure to respond to anticoagulant therapy. Retrievable filters were introduced to avoid long-term complications and risks associated with permanent filters. However, failure to follow up patients appropriately can lead to low retrieval rates. AIMS: To examine the practice of our institution in using retrievable IVC filters and to provide a review of published literature. METHODS: Retrospective audit of medical records in a single medical institution. RESULTS: Forty-one patients had retrievable IVC filters inserted. The median age of patients was 67. The majority (78%) of patients had filters inserted for presence of venous thromboembolism and contraindication to anticoagulation. Twenty-five (61%) patients received no clinical follow up. Factors associated with loss to follow up include a lack of documentation for retrieval plan (P < 0.01), lack of haematology outpatient clinic review (P < 0.01) and age greater than 50 years (P < 0.01). Procedural success was achieved in nine of 11 attempted filter removals. Eighteen complications were noted among patients. IVC filter insertion failed to prevent recurrent pulmonary embolisms in three patients. CONCLUSIONS: Majority of retrievable IVC filters will become lost to clinical follow up. Rates of attempted retrieval within 1 year of filter insertion are low. Loss to follow up is associated with older age, lack of documentation and lack of haematology clinic review post discharge. This study highlights the importance of a structured system to document clearly the review and retrieval plans for patients with IVC filters, at the time of initial insertion.
Asunto(s)
Implantación de Prótesis Vascular/tendencias , Auditoría Clínica/tendencias , Perdida de Seguimiento , Filtros de Vena Cava/tendencias , Vena Cava Inferior/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Australia/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Vena Cava Inferior/patología , Adulto JovenRESUMEN
Pulmonary arterial hypertension (PAH) is a major cause of mortality in scleroderma and despite 'advanced' therapies confers a median survival of less than 5 years. Anticoagulation in systemic sclerosis-related PAH (SSc-PAH) is currently one of the most contentious issues in the management of patients with connective tissue disease. While some studies have shown a survival benefit with warfarin therapy in this disease, others have not. Accordingly, a state of clinical equipoise exists in relation to anticoagulation in SSc-PAH. With an over fivefold reduction in mortality demonstrated in some observational studies, the issue of anticoagulation in SSc-PAH demands resolution through a well-designed randomised controlled trial.
Asunto(s)
Anticoagulantes/uso terapéutico , Hipertensión Pulmonar/tratamiento farmacológico , Hipertensión Pulmonar/epidemiología , Esclerodermia Sistémica/tratamiento farmacológico , Esclerodermia Sistémica/epidemiología , Hipertensión Pulmonar Primaria Familiar , HumanosRESUMEN
During early pregnancy, in response to the implanting embryo, the surrounding uterine stroma undergoes a dramatic transformation into a specialized tissue known as the decidua. The decidua encapsulates the developing embryo, facilitating nutrient transfer and limiting trophoblast invasion. Here we show that female mice with a null mutation of the interleukin-11 receptor alpha chain are infertile because of defective decidualization. A temporal analysis revealed IL-11 expression is maximal in the normal pregnant uterus at the time of decidualization, and in situ hybridization studies showed expression of the IL-11 and the IL-11 receptor alpha chain in the developing decidual cells. These observations reveal a previously unrecognized critical role for IL-11 signaling in female reproduction.
Asunto(s)
Decidua/fisiología , Implantación del Embrión/fisiología , Infertilidad Femenina/genética , Receptores de Interleucina/deficiencia , Útero/fisiología , Animales , Decidua/patología , Femenino , Expresión Génica , Interleucina-11/biosíntesis , Subunidad alfa del Receptor de Interleucina-11 , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Embarazo , Receptores de Interleucina/genética , Receptores de Interleucina-11 , Útero/patologíaRESUMEN
The vascular ectonucleotidases CD39[ENTPD1 (ectonucleoside triphosphate diphosphohydrolase-1), EC 3.6.1.5] and CD73[EC 3.1.3.5] generate adenosine from extracellular nucleotides. CD39 activity is critical in determining the response to ischemia-reperfusion injury (IRI), and CD39 null mice exhibit heightened sensitivity to renal IRI. Adenosine has multiple mechanisms of action in the vasculature including direct endothelial protection, antiinflammatory and antithrombotic effects and is protective in several models of IRI. Mice transgenic for human CD39 (hCD39) have increased capacity to generate adenosine. We therefore hypothesized that hCD39 transgenic mice would be protected from renal IRI. The overexpression of hCD39 conferred protection in a model of warm renal IRI, with reduced histological injury, less apoptosis and preserved serum creatinine and urea levels. Benefit was abrogated by pretreatment with an adenosine A2A receptor antagonist. Adoptive transfer experiments showed that expression of hCD39 on either the vasculature or circulating cells mitigated IRI. Furthermore, hCD39 transgenic kidneys transplanted into syngeneic recipients after prolonged cold storage performed significantly better and exhibited less histological injury than wild-type control grafts. Thus, systemic or local strategies to promote adenosine generation and signaling may have beneficial effects on warm and cold renal IRI, with implications for therapeutic application in clinical renal transplantation.
Asunto(s)
Antígenos CD/biosíntesis , Apirasa/biosíntesis , Daño por Reperfusión/prevención & control , Adenosina/metabolismo , Animales , Isquemia Fría , Humanos , Necrosis de la Corteza Renal/prevención & control , Ratones , Ratones Transgénicos , Modelos AnimalesRESUMEN
Thrombomodulin (TBM) is an important vascular anticoagulant that has species specific effects. When expressed as a transgene in pigs, human (h)TBM might abrogate thrombotic manifestations of acute vascular rejection (AVR) that occur when GalT-KO and/or complement regulator transgenic pig organs are transplanted to primates. hTBM transgenic mice were generated and characterized to determine whether this approach might show benefit without the development of deleterious hemorrhagic phenotypes. hTBM mice are viable and are not subject to spontaneous hemorrhage, although they have a prolonged bleeding time. They are resistant to intravenous collagen-induced pulmonary thromboembolism, stasis-induced venous thrombosis and pulmonary embolism. Cardiac grafts from hTBM mice to rats treated with cyclosporine in a model of AVR have prolonged survival compared to controls. hTBM reduced the inflammatory reaction in the vein wall in the stasis-induced thrombosis and mouse-to-rat xenograft models and reduced HMGB1 levels in LPS-treated mice. These results indicate that transgenic expression of hTBM has anticoagulant and antiinflammatory effects that are graft-protective in murine models.
Asunto(s)
Antiinflamatorios/farmacología , Ciclosporina/farmacología , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Transgénicos , Ratas , Porcinos , Trombomodulina , Transgenes/efectos de los fármacosRESUMEN
SHIP-2 is a phosphoinositidylinositol 3,4,5 trisphosphate (PtdIns[3,4,5]P3) 5-phosphatase that contains an NH2-terminal SH2 domain, a central 5-phosphatase domain, and a COOH-terminal proline-rich domain. SHIP-2 negatively regulates insulin signaling. In unstimulated cells, SHIP-2 localized in a perinuclear cytosolic distribution and at the leading edge of the cell. Endogenous and recombinant SHIP-2 localized to membrane ruffles, which were mediated by the COOH-terminal proline-rich domain. To identify proteins that bind to the SHIP-2 proline-rich domain, yeast two-hybrid screening was performed, which isolated actin-binding protein filamin C. In addition, both filamin A and B specifically interacted with SHIP-2 in this assay. SHIP-2 coimmunoprecipitated with filamin from COS-7 cells, and association between these species did not change after epidermal growth factor stimulation. SHIP-2 colocalized with filamin at Z-lines and the sarcolemma in striated muscle sections and at membrane ruffles in COS-7 cells, although the membrane ruffling response was reduced in cells overexpressing SHIP-2. SHIP-2 membrane ruffle localization was dependent on filamin binding, as SHIP-2 was expressed exclusively in the cytosol of filamin-deficient cells. Recombinant SHIP-2 regulated PtdIns(3,4,5)P3 levels and submembraneous actin at membrane ruffles after growth factor stimulation, dependent on SHIP-2 catalytic activity. Collectively these studies demonstrate that filamin-dependent SHIP-2 localization critically regulates phosphatidylinositol 3 kinase signaling to the actin cytoskeleton.
Asunto(s)
Actinas/metabolismo , Proteínas Contráctiles/metabolismo , Proteínas de Microfilamentos/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Secuencia de Aminoácidos , Animales , Células COS/efectos de los fármacos , Células COS/enzimología , Membrana Celular/enzimología , Proteínas Contráctiles/genética , Factor de Crecimiento Epidérmico/farmacología , Filaminas , Humanos , Inositol Polifosfato 5-Fosfatasas , Melanoma , Ratones , Proteínas de Microfilamentos/genética , Datos de Secuencia Molecular , Fibras Musculares Esqueléticas/química , Músculo Esquelético/química , Músculo Esquelético/citología , Miocardio/química , Miocardio/citología , Sondas de Oligonucleótidos , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatasas , Fosfatidilinositoles/metabolismo , Monoéster Fosfórico Hidrolasas/análisis , Monoéster Fosfórico Hidrolasas/genética , Células Tumorales Cultivadas , Técnicas del Sistema de Dos Híbridos , LevadurasRESUMEN
Incompatibility between pig thrombomodulin (TM) and primate thrombin is thought to be an important factor in the development of microvascular thrombosis in rejecting pig-to-primate xenografts. To examine this interaction at the molecular level, we cloned pig TM and measured its ability to bind human thrombin and act as a cofactor for the activation of human protein C and TAFI. The 579-residue pig TM protein showed approximately 69% sequence identity to human TM. Within the EGF domains necessary for binding of thrombin (EGF56), protein C (EGF4) and TAFI (EGF3), all of the amino acids previously identified as critical for the function of human TM, with the exception of Glu-408 in EGF5, were conserved in pig TM. Comparison of transfected cells expressing pig or human TM demonstrated that both proteins bound human thrombin and inhibited its procoagulant activity. However, pig TM was a poor cofactor for the activation of human protein C and TAFI, with domain swapping showing that EGF5 was the most important determinant of compatibility. Thus, while pig TM may be capable of binding thrombin generated in the vicinity of xenograft endothelium, its failure to promote the activation of human protein C remains a significant problem.
Asunto(s)
Proteína C/metabolismo , Trombina/metabolismo , Trombomodulina/metabolismo , Trasplante Heterólogo/efectos adversos , Animales , Carboxipeptidasa B2/metabolismo , Coenzimas/metabolismo , Activación Enzimática , Rechazo de Injerto/metabolismo , Humanos , Microcirculación , Unión Proteica , Porcinos , Trombosis/metabolismoRESUMEN
We describe the molecular cloning of a cDNA for the alpha chain of the human IL-11 receptor (IL-11R alpha) and demonstrate the requirement of either the human or mouse gp130 molecule for signalling. cDNA clones encoding IL-11R alpha were isolated from a bone marrow cDNA library using a fragment from the murine IL-11R alpha as a probe. The human receptor was predicted to consist of 422 amino acids and was found to share 84% identity with the murine protein. In the extra-cellular region it exhibited a single hemopoietin domain with conserved cysteine residues and WSTWS motif. The transmembrane region was followed by a short cytoplasmic tail which did not contain a tyrosine kinase domain. Interaction of the human IL-11R alpha with murine gp130 was demonstrated: expression of the human IL-11R alpha in murine M1 cells which constitutively express murine gp130 (and murine LIF receptor), resulted in the generation of specific high-affinity binding sites for IL-11 (Kd = 250 pM). In addition, expression of the human IL-11R alpha in these cells permitted the induction of macrophage differentiation in response to IL-11. These results suggested that the human IL-11R alpha chain was able to form a functional receptor complex in association with murine gp130. The requirement of gp130 for signalling was confirmed by expression of the human IL-11R alpha in Ba/F3 cells. BaF3 cells that expressed the human IL-11R alpha alone showed binding of radiolabelled IL-11 but no proliferative response. Introduction of human gp130 into these cells resulted in high-affinity IL-11 binding sites and IL-11 dependent cellular proliferation. Thus these results demonstrated the absolute requirement of gp130 for signalling.
Asunto(s)
Antígenos CD/metabolismo , Inhibidores de Crecimiento , Interleucina-6 , Linfocinas , Glicoproteínas de Membrana/metabolismo , Receptores de Interleucina/fisiología , Transducción de Señal , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Southern Blotting , División Celular/efectos de los fármacos , Clonación Molecular , Receptor gp130 de Citocinas , Factores de Crecimiento de Célula Hematopoyética/química , Humanos , Interleucina-11/farmacología , Subunidad alfa del Receptor de Interleucina-11 , Factor Inhibidor de Leucemia , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia , Ratones , Datos de Secuencia Molecular , Receptores de Citocinas/biosíntesis , Receptores de Citocinas/metabolismo , Receptores de Interleucina/biosíntesis , Receptores de Interleucina/química , Receptores de Interleucina-11 , Receptores OSM-LIF , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , TransfecciónRESUMEN
OBJECTIVE: mpl(-/-) mice have a profound defect in platelets and megakaryocytes and a defect in hematopoietic progenitor cells and stem cells. However, no specific subset of the progenitor/stem cell compartment has been shown to be particularly affected by this deficiency in mpl(-/-) mice. In this article, we identified a specific subset of bone marrow progenitor/stem cells that was altered in mpl(-/-) mice. MATERIALS AND METHODS: In vitro and in vivo hematopoietic assays were utilized to examine the response to interleukin-11 in mice lacking the receptor for thrombopoietin (TPO) (mpl(-/-) mice). RESULTS: The interleukin (IL)-11-responsive subset of progenitor cells was not detected in clonal cultures of bone marrow cells from mpl(-/-) mice. However, mpl(-/-) mice responded to IL-11 in vivo as evidenced by a rise in platelet count and an increase in spleen weight. Experiments were performed to address this paradox: administration of 5-fluorouracil with consequent "expansion" of early hematopoietic cells resulted in the appearance of IL-11-responsive cells in mpl(-/-) mice when assayed in in vitro cultures. CONCLUSIONS: Thus, although mpl(-/-) mice have the capacity to produce IL-11-responsive progenitor cells, under steady state conditions their expansion is dependent on TPO. This is the first evidence that a specific subset of bone marrow progenitor/stem cells is altered in mpl(-/-) mice.
Asunto(s)
Células Madre Hematopoyéticas/efectos de los fármacos , Interleucina-11/farmacología , Proteínas de Neoplasias , Receptores de Citocinas , Transducción de Señal , Trombopoyetina/fisiología , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Sinergismo Farmacológico , Fluorouracilo/farmacología , Células Madre Hematopoyéticas/citología , Humanos , Interleucina-3/farmacología , Interleucina-6/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Recuento de Plaquetas , Proteínas Proto-Oncogénicas/deficiencia , Proteínas Proto-Oncogénicas/fisiología , Receptores de Trombopoyetina , Bazo/citología , Factor de Células Madre/farmacología , Trombopoyetina/deficiencia , Trombopoyetina/genéticaRESUMEN
The BTK (Bruton's tyrosine kinase) inhibitor ibrutinib is associated with an increased risk of bleeding. A previous study reported defects in collagen- and adenosine diphosphate (ADP)-dependent platelet responses when ibrutinib was added ex vivo to patient samples. Whereas the collagen defect is expected given the central role of BTK in glycoprotein VI signaling, the ADP defect lacks a mechanistic explanation. In order to determine the real-life consequences of BTK platelet blockade, we performed light transmission aggregometry in 23 patients receiving ibrutinib treatment. All patients had reductions in collagen-mediated platelet aggregation, with a significant association between the degree of inhibition and the occurrence of clinical bleeding or bruising (P=0.044). This collagen defect was reversible on drug cessation. In contrast to the previous ex vivo report, we found no in vivo ADP defects in subjects receiving standard doses of ibrutinib. These results establish platelet light transmission aggregometry as a method for gauging, at least qualitatively, the severity of platelet impairment in patients receiving ibrutinib treatment.
Asunto(s)
Antineoplásicos/efectos adversos , Plaquetas/efectos de los fármacos , Colágeno/farmacología , Hemorragia/diagnóstico , Agregación Plaquetaria/efectos de los fármacos , Pirazoles/efectos adversos , Pirimidinas/efectos adversos , Adenina/análogos & derivados , Adenosina Difosfato/farmacología , Anciano , Anciano de 80 o más Años , Antineoplásicos/administración & dosificación , Plaquetas/patología , Células Cultivadas , Femenino , Hemorragia/inducido químicamente , Hemorragia/patología , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/patología , Linfoma de Células del Manto/tratamiento farmacológico , Linfoma de Células del Manto/patología , Masculino , Persona de Mediana Edad , Piperidinas , Pirazoles/administración & dosificación , Pirimidinas/administración & dosificación , Índice de Severidad de la EnfermedadRESUMEN
The gene for the murine interleukin-11 receptor alpha chain (mIL-11R alpha) contains two loci (1 and 2), of which locus 2 is restricted to only some mouse strains. Two alternatively spliced exons (1a and 1b) encode the 5' untranslated region (5'UTR) of the murine locus 1. We have characterized the gene for the human interleukin-11 receptor alpha chain locus (hIL-11R alpha), examined its expression by Northern analysis and determined its chromosomal location by fluorescence in situ hybridization. The presence of exon(s) encoding the 5'UTR and mapping of transcription initiation sites was determined by reverse-transcriptase polymerase chain reaction and 5' rapid amplification of cDNA ends (5'RACE) techniques. The human locus spanned 10 kilobasepairs (kb) and consisted of 14 exons. Two alternatively spliced first exons (1a and 1b) encoding the 5'UTR were identified and shared 76 and 73% nucleotide identity with murine exons 1a and 1b. Multiple transcription start sites were demonstrated for human exon 1a. The promoter regions of both human exons 1a and 1b did not display a canonical TATA box. A predominant 1.8 kb transcript for the hIL-11R alpha was present in heart, brain, skeletal muscle, lymph nodes, thymus, appendix, pancreas and foetal liver. The hIL-11R alpha gene was localized to chromosome 9p13. In summary, the hIL-11R alpha gene was highly related to locus 1 of the murine gene and there was no evidence of a second hIL-11R alpha locus.
Asunto(s)
Empalme Alternativo , Exones , Receptores de Interleucina/genética , Animales , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Humanos Par 9 , ADN , Humanos , Subunidad alfa del Receptor de Interleucina-11 , Ratones , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Receptores de Interleucina-11 , Mapeo Restrictivo , Transcripción GenéticaRESUMEN
We have investigated the compartmentalization of aminopeptidase-N-like activity in various blood fractions obtained from patients with acute lymphoid (ALL) or myeloid (AML) leukemia. The primary difference appears not to be the absolute level of overall activity, but rather the relative proportions of the different forms of activity detected. Thus, despite similar levels of total aminopeptidase-N-like activity detected in cells from different leukemic groups, true aminopeptidase-N/CD13 activity was only detected in cells derived from AML patients. Even in these patients, however, most of the detected aminopeptidase-N-like activity ( > 80%) could not be attributed to aminopeptidase-N/CD13. In marked contrast, plasma from leukemic patients also contained substantial total aminopeptidase-N-like activity, of which (irrespective of leukemic group) most could be attributed to aminopeptidase-N/CD13. Whilst slightly higher levels of total activity were obtained in plasma from AML patients compared to ALL patients, there was no difference in the relative proportion attributable to aminopeptidase-N/CD13 (approximately 80% of total aminopeptidase-N-like activity). Evaluation of total aminopeptidase-N-like activity present in whole blood gave differential patterns, and whilst only a proportion (20-40% of total aminopeptidase-N-like activity) could be attributed to true aminopeptidase-N/CD13, blood from patients with CD13+ AML showed the greatest activity so attributable. In total, our results outline the complexities of peptidase activities present within blood of leukemic individuals, and may, in part, explain the variability of previous studies attempting to associate prognostic features with phenotypic expression of CD13.
Asunto(s)
Antígenos CD13/sangre , Leucemia Mieloide Aguda/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Anticuerpos Bloqueadores/inmunología , Anticuerpos Monoclonales/inmunología , Humanos , Leucemia Mieloide Aguda/sangre , Leucemia Mieloide Aguda/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunologíaRESUMEN
In clinical chemistry, determination of serum alanine aminopeptidase (AAP) levels has been found to be useful for detecting or confirming biliary obstructions from either intra- or extra-hepatic disorders. In haematology, 'gp150' is a surface-expressed protein molecule, recognised by monoclonal antibodies belonging to the so-called 'Cluster of Differentiation' (CD-) 13, which has independently been found to be a useful marker of myeloid leukaemia in addition to providing potential prognostic value. The current report links these two independent research streams and provides evidence that the hepatobiliary disease marker, serum AAP, predominantly comprises a circulating isoform of 'gp150'. Thus, a (CD-13) monoclonal antibody raised to, and specifically reactive with, cell surface myeloid 'gp150' is able to specifically and almost completely block serum (or plasma) AAP activity otherwise observed in its absence. This holds true for serum (or plasma) derived both from normal individuals or from patients suffering hepatic dysfunction, with or without associated biliary obstruction. In the case of patients with obstructive jaundice, raised levels of AAP are observed, which fall to near normal levels following preincubation with this monoclonal antibody. In addition, data are presented to support the view of varying isoforms of AAP within flowing blood. Finally, preliminary data is provided on AAP activity in cases of leukaemia. These studies should thus prove of use to clinical laboratories investigating the involvement of AAP activity in various pathological processes.