Study of Megakaryocytes From Patients With Abnormal Platelet Vesicles
Blood Coagulation DisordersCongenital bleeding disorders characterized by abnormal platelet granules include Gray Platelet syndrome (GPS; defective alpha-granules), Hermansky-Pudlak syndrome (HPS; defective delta-granules), and combined alpha delta-storage pool deficiency (alpha delta-SPD). Other diseases associated with variable defects in platelet gamma-granules include Chediak-Higashi, Griscelli, Wiskott-Aldrich, and Thrombocytopenia Absent Radius syndromes. These disorders are models for the study of organelle formation in megakaryocytes and platelets. Characteristics of megakaryocytopoiesis in these disorders have not been investigated because megakaryocytes could not be cultured from patients in sufficient quantities for experimental purposes. Recent advances have made it possible to culture megakaryocytes using serum-free media supplemented with recombinant human thrombopoietin (TPO). Such cultured human megakaryocytes, amplified from bone marrow-derived CD34+ stem cells, synthesize and store organellar proteins and produce functional platelets. In this protocol, we plan to obtain bone marrow aspirates from 40 children and adults (ages 2 to 80 years) with GPS, HPS, and related disorders. Patients admitted to the NIH Clinical Center on specific disease-related protocols will be enrolled in this protocol during their routine 3-5 day visits. We will culture megakaryocytes from CD34+ stem cells isolated from bone marrow aspirates. Studies of cultured megakaryocytes will include evaluation of granule membrane and soluble proteins using fluorescent antibodies and immunoelectron microscopy and comparison of RNA and protein expression patterns between normal and patient cells. Precautions will be taken to prevent the primary risk of the bone marrow aspiration, i.e., prolonged bleeding at the aspiration site. Standard diagnostic studies on the bone marrow sample may reveal information that may directly benefit patients. However, the broader benefit of this study is the acquisition of a better understanding of the characteristics of functional platelet disorders and the process of intracellular vesicle formation.
Hypercoagulability After Breast Cancer Surgery
Breast CancerBlood Coagulation DisordersThe risk of deep venous thrombosis after radical breast surgery is known. The objective of this study is to explore hypercoagulability after radical breast cancer surgery by studying several factors for haemostasis before, during and after surgery. Ultrasound Doppler examination is realised between 24 and 72 hours post-operatively. Hypercoagulability is defined by a significant increasing level of thrombin-antithrombin, D-dimer and the endogen thrombin potential.
Epidemiology of Impaired Coagulant Balance in Diabetes
Cardiovascular DiseasesHeart Diseases2 moreTo determine the nature, extent and molecular mechanisms responsible for impaired fibrinolysis in White, Black, Hispanic and American Indian populations with respect to the presence or absence of diabetes. The overall objective is to determine whether impairments of fibrinolysis underlie subclinical and clinical vascular disease in diabetes in specific populations with and without accelerated microvascular disease.
To Quantify the Range of Main Psychosocial Factors Affecting Patients and Caregivers in Their Daily...
Congenital Bleeding DisorderHaemophilia A4 moreThis survey is conducted in South America. The purpose is to identify the key psychosocial issues affecting patients with haemophilia.
Evaluating the Use of Thromboelastography to Diagnose Coagulopathy After Traumatic Brain Injury...
Traumatic Brain InjuryCoagulation DisorderThe investigators will obtain thromboelastography (TEG) on pediatric patients admitted to the Rady Children's Hospital ICU after traumatic brain injury on admission to our ICU and after 24 hours of care. The investigators hypothesize that TEG will identify abnormalities of coagulation that are not identified by traditional coagulation studies, i.e. prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (INR).
Comparison of Two D-Dimers Dosing Techniques
Blood Coagulation DisorderStudy of the possibility of substitution of the automated STAGO D-Dimers method with the semi-automated VIDAS method, which is more expensive, longer to implement and requires the use of a dedicated automaton.
AAV Gene Therapy Screening/Observational Protocol (ECLIPSE)
Hemophilia BBlood Coagulation Disorders3 moreFreeline is developing adeno-associated virus (AAV) vector based gene therapies for a number of diseases and is actively advancing a programme in Haemophilia B (HB). This study aims to collect prospective data to characterise bleeding events and Factor IX (FIX) concentrate consumption in HB patients that can be used as baseline for participants who elect to participate in a subsequent Freeline gene therapy study. The study will also screen participants for antibodies to a novel AAV vector to assess their suitability for inclusion in a Freeline gene therapy treatment study.
Reference Range Study for the Quantra QStat System
Coagulation DisorderThe objective is to determine the reference range intervals for the parameters reported by the Quantra System with the QStat Cartridge.
Assessment of Hemostatic Profile in Liver Cirrhosis
Coagulation DisorderOur study included both in- and outpatients suffering from liver cirrhosis attending the out- and inpatient care of the department of hepatology. Demographic and biochemical data as well as medical history including cause of liver cirrhosis, end stage kidney failure and medication with anticoagulants were recorded. To assess the hemostatic profile, platelet function was analyzed by multiple electrode aggregometry (MEA) using Multiplate (ADP-, ASPI- and TRAP-test) and thrombelastometry using ROTEM (EXTEM, INTEM, FIBTEM).
The Glycocalyx in COVID-19 Patients. A Pilot Study
COVID-19Endothelial Dysfunction1 moreThe damage of the endothelial glycocalyx is based on microvascular endothelial dysfunction and typical for critical clinical conditions like sepsis, trauma, bleeding, shock, as well as ARDS. We aim to generate first hints regarding the impact of covid-19 disease on the (damage) of the endothelial glycocalyx. Furthermore, we want to investigate the potential coagulopathies, which go along with shedding of the glycocalyx. The detection of and the relation between the severity of the disease, as well as the extent of the glycocalyx damage during the observational period, as well as the hemostatic alterations, are aim of the study.