In resting platelets, the 17 ^th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 ^rd phenylalanine (PHE ⁵⁶³-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
Filamins/metabolism* ; Platelet Glycoprotein GPIb-IX Complex/metabolism* ; Molecular Dynamics Simulation ; Ligands ; Protein Binding ; Blood Platelets/metabolism* ; von Willebrand Factor/metabolism*

Factor IX/therapeutic use* ; Factor VIII ; Hemophilia A/drug therapy* ; Hemophilia B/drug therapy* ; Humans ; Recombinant Proteins/therapeutic use*

OBJECTIVE: To investigate the molecular mechanism in stable cell strains expressing Mini-hF9 gene with nonsense mutation. METHODS: Mini-hF9 gene and its nonsense mutants were transfected into HeLa cells independently, and stable cell strains were obtained after G418 resistance screening and monoclonal transformation. The altered splicing and protein expression of mRNA in Mini-hF9 gene in stable cell strains were detected by using RT-PCR and Western blot. RESULTS: The wild type and nonsense mutated human coagulation factor IX stable cell strains were constructed successfully, which were named HeLa-F9-WT, HeLa-F9-M1 and HeLa-F9-M2. Only normal splicing Norm was detected in the wild-type cell strain HeLa-F9-WT; Norm and Alt-S1 splicing were detected in HeLa-F9-M1; while Norm, Alt-S1 and Alt-S2 splicing were detected in HeLa-F9-M2. CONCLUSION The nonsense associated altered splicing (NAS) pathway, which generated alternately spliced transcripts, might be triggered in coagulation factor IX gene with nonsense mutation.
Codon, Nonsense ; Factor IX/metabolism* ; HeLa Cells ; Humans ; Mutation ; RNA Splicing ; RNA, Messenger/metabolism*

BACKGROUND: Risk factors for the development of inhibitors in previously untreated patients (PUPs) have been reported; this is not the case in previously treated patients (PTPs) owing to fewer studies. Risk factors may differ for the development of PTP versus PUP inhibitors. We aimed to identify risk factors for PTP inhibitor development. METHODS: Participants were patients at a hemophilia treatment center in Korea with current or past history of factor VIII or factor IX alloantibodies. Observed inhibitors were classified as PUP or PTP inhibitors based on the cumulative number of exposure days. We compared the type and severity of hemophilia, mutation type, and family history of inhibitor between PUPs and PTPs. Events within 3 months before the first inhibitor detection, such as change of the factor concentrate used, short-term high exposure or continuous infusion of factor concentrate, history of surgery, infection, diagnosis of cancer, use of immunosuppressive or immunomodulator agents, and vaccination were compared between PUPs and PTPs. RESULTS: We observed 5 PUP inhibitors and 5 PTP inhibitors in 115 patients with hemophilia A. Events that might be related to the development of inhibitors within 3 months prior to the first inhibitor detection were observed in all 5 PTPs. On the contrary, no such events were observed in any PUPs. The observed events included a change in the factor concentrate used, subsequent chemotherapy, and short-term high exposure to factor concentrates for controlling hemorrhage and surgeries. CONCLUSION: Our results suggest a greater role of nongenetic factors in PTP inhibitor development.
Diagnosis ; Drug Therapy ; Factor IX ; Factor VIII ; Hemophilia A ; Hemorrhage ; Humans ; Isoantibodies ; Korea ; Prevalence ; Risk Factors ; Vaccination

BACKGROUND: Korean National Health Insurance reimburses factor VIII (FVIII) and factor IX (FIX) clotting factor concentrate (CFC) infusions to discrepant activity levels, allowing elevation of FVIII activity to 60 IU/dL and FIX to 40 IU/dL. We aimed to assess hemostatic response to these target levels using global hemostatic assays. METHODS: We enrolled 34 normal healthy men, 34 patients with hemophilia A, and 36 with hemophilia B, with residual factor activity of 3 IU/dL or less and without inhibitors. Patients with hemophilia A and B received injected CFCs according to reimbursement guidelines. Fifteen minutes after injection, we assessed hemostatic response with global hemostatic assays: thrombin generation assay (TGA), thromboelastography (TEG), and clot waveform analysis (CWA). RESULTS: Normal healthy men and patients with hemophilia A and B were 36.7, 37.2, and 35.1 years old, respectively. FVIII and recombinant FIX concentrate doses were 28.8 IU/kg and 43.6 IU/kg. Post-infusion FVIII activity rose from 0.5 IU/dL to 69.4 IU/dL, while FIX activity rose from 1.4 IU/dL to 46.8 IU/dL. Post-infusion peak thrombin concentrations in hemophilia A and B were 116.6 nM/L and 76.4 nM/L (P < 0.001). Post-infusion endogenous thrombin potential (ETP) in hemophilia A and B was 1349.8 nM/min and 915.6 nM (P < 0.001). TEG index of hemophilia A and B was 0.11 and −0.51 (P=0.006). CONCLUSION: Current reimbursed doses for FIX concentrates are insufficient to achieve hemostatic responses comparable to those after reimbursed doses for FVIII concentrates in terms of peak thrombin concentration, ETP, and TEG index.
Factor IX* ; Factor VIII* ; Hemophilia A ; Hemophilia B ; Humans ; Male ; National Health Programs ; Thrombelastography ; Thrombin

Hemophilia is an X-linked recessive disorder, which is classified into hemophilia A, defined by factor VIII deficiency and hemophilia B, defined by factor IX deficiency. The usual clinical presentation is spontaneous bleeding and prolonged activated partial thromboplastin time in a person without history of a coagulation disorder. The severity of hemophilia describes how serious a problem is and has been defined by a traditional classification into three forms: severe, moderate, mild. Hemophilia has never been reported after a rhinosinus surgery in otorhinolaryngology in Korea, but we encountered a 37-year-old man with hemophilia B who had undergone a rhinosinus surgery. He had no bleeding tendency in the past nor a family history for bleeding. But the patient presented with continuous nasal bleeding for a few days after surgery. We report this case of hemophilia B diagnosed after rhinosinus surgery that was cured with Factor IX replacement therapy with a review of the relevant literature.
Adult ; Classification ; Endoscopy ; Epistaxis ; Factor IX ; Hemophilia A* ; Hemophilia B* ; Hemorrhage ; Humans ; Korea ; Otolaryngology ; Partial Thromboplastin Time

Objective: To evaluate the efficacy and safety of a domestic human plasma derived coagulation Factor Ⅸ concentrate (pd-FⅨ) in patients with hemophilia B. Methods: The study was a multicenter, open-label and single-arm study. The efficacy of pd-F Ⅸ was evaluated by objective performance criteria. The doses of pd-FⅨ were calculated according to the bleeding symptom and disease severity. The infusion efficiency of pd-FⅨ and improvement of bleeding symptoms were measured at 30 minutes and (24±4) h after the first infusion, respectively. Adverse events were recorded. Viral infection and FⅨ inhibitor were detected 90 d after the first infusion. Results: All 36 subjects with hemophilia B were enrolled in the study. The median age of these patients was 31 years old and the median injection doses were 4 (1-17) times. The hemostatic effect of 27/36 (75.00%) and 9/36 (25.00%) acute bleeding events were rated as "excellent" and "better" , respectively. The recovery rate was 111.92% (65.55%-194.28%) at 30 minutes after infusion of FⅨ. There was no adverse event related to FⅨ. No reactivation of HBV, HCV or HIV and FⅨ inhibitor was detected at 90-104 d after the first FⅨ infusion. Conclusion: This domestically made human plasma derived FⅨ concentrate is safe and effective in the treatment of acute bleeding in patients with hemophilia B. Clinical trial registration: China food and Durg Administration, 2016L08027.
Adult ; China ; Factor IX ; Hemophilia A ; Hemophilia B/therapy* ; Hemorrhage ; Humans ; Plasma

OBJECTIVE: To identify risk factors associated with disease recurrence among Filipinos with papillary thyroid carcinoma (PTC).
METHODS:
Design: Retrospective Cohort Study
Setting: Tertiary National University Hospital
Participants: 76 patients diagnosed with papillary thyroid carcinoma, classified as low and low-to-intermediate risk (2015 ATA classification) that underwent total thyroidectomy with or without neck dissection from 2010-2014 and were followed up from 10 months to 5 years. Log rank and Cox regression analyses were used to determine significant risk factors for recurrence.
RESULTS: 29 (38.15%) had recurrence. On univariate analysis, age, tumor size, multifocality, extrathyroidal extension, presence of lateral neck nodes and RAI therapy were statistically associated with recurrence. However, on multivariate analysis, no clinicopathologic factor was statistically associated with recurrence.
CONCLUSION: Age of >45 years, female sex, tumor size of >2 cm, multifocality, presence of microscopic extrathyroidal extension and lymph node metastasis might contribute to the recurrence of papillary thyroid cancer while post-operative radioactive ablation may have some protective effect. However, this study suggests that other factors must be included in the model to better understand the relationship between these factors and recurrence.

Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Thyroid Cancer, Papillary ; Neck Dissection ; Thyroidectomy ; Thyroid Neoplasms ; Lymphatic Metastasis ; Lymph Nodes ; Regression Analysis ; Factor Ix

Gastrointestinal hemorrhage in neonates is commonly associated with necrotizing enterocolitis, cow's milk protein allergy, and gastrointestinal malformation. Gastrointestinal bleeding on the first day of life, presenting as the first manifestation of a disorder, has rarely been reported associations with gastric ulceration, Salmonella infection, and allergic colitis. Hemophilia B is also a rare cause of gastrointestinal bleeding during the neonatal period. In the present case, a male infant developed repetitive hematemesis on the first day of life. His initial level of coagulation factor IX was 1.9%, and he was diagnosed with moderate hemophilia B. No further hematemesis or melena was observed during recombinant factor IX therapy. The infant did not have a family history of hemophilia. In conclusion, although gastrointestinal hemorrhage on the first day of life as the first manifestation of a disease is rare, infants who present with spontaneous gastrointestinal hemorrhage after birth and with unexplained prolonged activated partial thromboplastin time should be evaluated for coagulation factor deficiency regardless of whether they have any family history of hemophilia.
Blood Coagulation Factors ; Colitis ; Enterocolitis, Necrotizing ; Factor IX ; Gastrointestinal Hemorrhage* ; Hematemesis ; Hemophilia A* ; Hemophilia B* ; Hemorrhage ; Humans ; Hypersensitivity ; Infant ; Infant, Newborn ; Male ; Melena ; Milk Proteins ; Partial Thromboplastin Time ; Parturition ; Salmonella Infections ; Stomach Ulcer

PURPOSE: Molecular genetic analysis is the main approach used for prenatal diagnosis of hemophilia A and B. However, in certain cases, such analysis is uninformative. In such situations, direct measurement of fetal coagulation factor levels is still the best option, and it may be the only option in some cases. This study was conducted to determine the normal ranges of midtrimester cord blood factor VIII (FVIII) and IX (FIX) in a Korean population. MATERIALS AND METHODS: Twenty-six FVIII samples and 29 FIX samples were assayed in fetal cord blood acquired by ultrasound-guided cordocentesis. Sampling was conducted during gestational ages of 19-24 weeks. RESULTS: The mean and standard deviations for FVIII and FIX activity were 45.5±30.5% and 19.9±12.2%, respectively. Ranges for FVIII and FIX were 1.5-125.0% and 6.0-52.0%, respectively. CONCLUSION: Our study revealed the normal ranges and lowest level of factor VIII and factor IX in non-affected normal fetus by fetal cord blood sampling during the mid-trimester in a Korea population. The factor assay of the fetal cord blood is invasive but feasible and provides important basic data related to hemophilia.
Blood Coagulation Factors ; Cordocentesis ; Factor IX ; Factor VIII* ; Female ; Fetal Blood* ; Fetus* ; Gestational Age ; Hemophilia A* ; Humans ; Korea ; Molecular Biology ; Pregnancy ; Pregnancy Trimester, Second ; Prenatal Diagnosis ; Reference Values