[Application of Bionano-DNA Full-Length Optical Mapping Technology in Genetic Diagnosis of Hemophilia A Carriers].

OBJECTIVE: To apply Bionano Saphyr visual full-length DNA optical mapping technology to the precise genetic diagnosis of hemophilia A carriers. METHODS: For 2 suspected F8 gene deficiency female carriers who could not be diagnosed by conventional next-generation sequencing technology, the full-length DNA optical mapping technology was used to detect and scan the sample X chromosome full-length visual haplotype characteristic map, which was compared with the normal haplotype. The gene structure variation information of the samples was obtained by compare with DNA atlas library. RESULTS: The average fluorescent marker length of the X chromosome DNA molecular where the F8 gene was located in the two samples was greater than 2.5 Mbp, and the average copy number was greater than 20×. After comparative analysis, one of the samples was a proximal inversion of intron 22 of the F8 gene, and another was an inversion of intron 22 accompanied by multiple deletions of large fragments. CONCLUSIONS: Bionano technology has a good detection rate for gene defects with large length and complex variation. In the absence of a proband or accurate genetic diagnosis results of the proband, the application of this technology to detect the heterozygous complex variant of the F8 gene is of great significance for the prenatal diagnosis and pre-pregnancy diagnosis of hemophilia carriers.

Colchicine in High-risk Patients with Acute Minor-to-moderate Ischemic Stroke or Transient Ischemic Attack (CHANCE-3): Rationale and design of a multicenter randomized placebo-controlled trial.

BACKGROUND: Anti-inflammatory therapy using colchicine has reduced recurrent vascular events in patients with coronary heart disease. DESIGN: Colchicine in High-risk Patients with Acute Minor-to-moderate Ischemic Stroke or Transient Ischemic Attack (CHANCE-3) is a randomized, double-blind, placebo-controlled multicenter trial, in which 8,238 patients with acute minor-to-moderate ischemic stroke (NIHSS ⩽ 5) or high-risk transient ischemic attack (TIA) (ABCD2 score ⩾4) and a high-sensitivity CRP (hsCRP) level of ⩾2 mg/L will be randomly assigned within 24 h of symptom onset to colchicine (1 mg daily on days 1-3, followed by 0.5 mg daily for a total of 90 days) or matching placebo, on a background of optimal medical therapy. The study will have 90% power to detect a 25% reduction in the primary efficacy outcome of any stroke within 3 months of randomization. Adverse events potentially related to the use of colchicine will also be analyzed. The primary analysis will be by intention to treat. TRIAL REGISTRY NAME: Colchicine in High-risk Patients with Acute Minor-to-moderate Ischemic Stroke or Transient Ischemic Attack (CHANCE-3); URL: https://clinicaltrials.gov/ct2/show/NCT05439356?cond=CHANCE-3&draw=2&rank=1; Registration number: NCT05439356.

Effect of different doses of colchicine on high sensitivity C-reactive protein in patients with acute minor stroke or transient ischemic attack: A pilot randomized controlled trial.

BACKGROUND AND PURPOSE: Patients with elevated levels of high-sensitivity C-reactive protein (hsCRP) are at increased risk of recurrent stroke. Colchicine is a unique anti-inflammatory medication that has shown promise in reducing cardiovascular event. The current study mainly tested the ability of colchicine at different doses to reduce hsCRP levels after stroke. METHODS: This was a randomized controlled and open label trial. Eligible patients with acute minor ischemic stroke or transient ischemic attack (TIA) were randomized within 24 h after symptom onset in a 1:1:1:1 ratio to four groups with different doses of colchicine. Group 1: 0.5 mg of colchicine per day for 14 days; groups 2: starting with 1 mg of colchicine on days 1 through 7, and maintaining with 0.5 mg per day on days 8 through 14; group 3 and 4: respectively, 2 mg and 3 mg of colchicine on day 1, following with 1 mg per day on days 2 through 7 and continuing with 0.5 mg per day on days 8 through 14. Blood specimens were collected at randomization, 24 h, 72 h, 7 days and 14 days after index event for hsCRP measurements. The primary outcome was the change of hsCRP levels between baseline and 14 days. RESULTS: A total of 39 patients were enrolled. Patients in group 2 had reduced level of hsCRP at 14-day compared with baseline value (p = 0.005). Time-course analyses showed that patients in groups of 1 and 2 had lower hsCRP level at 7-day than that at baseline, and patients in groups of 1, 2 and 3 had lower ratios of hsCRP levels at 72 h to those at baseline. Low dose of colchicine was well tolerated without discontinuation of drug. CONCLUSION: Early treatment with low dose of colchicine reduced hsCRP levels in the patients with acute minor ischemic stroke and TIA.

Blocking human protein C anticoagulant activity improves clotting defects of hemophilia mice expressing human protein C.

Hemophilia A and B are hereditary coagulation defects resulting in unstable blood clotting and recurrent bleeding. Current factor replacement therapies have major limitations such as the short half-life of the factors and development of inhibitors. Alternative approaches to rebalance the hemostasis by inhibiting the anticoagulant pathways have recently gained considerable interest. In this study, we tested the therapeutic potential of a monoclonal antibody, HAPC1573, that selectively blocks the anticoagulant activity of human activated protein C (APC). We generated F8-/- or F9-/- hemophilia mice expressing human protein C by genetically replacing the murine Proc gene with the human PROC. The resulting PROC+/+;F8-/- or PROC+/+;F9-/- mice had bleeding characteristics similar to their corresponding F8-/- or F9-/- mice. Pretreating the PROC+/+;F8-/- mice with HAPC1573 shortened the tail bleeding time. HAPC1573 pretreatment significantly reduced mortality and alleviated joint swelling, similar to those treated with either FVIII or FIX, of either PROC+/+;F8-/- or PROC+/+;F9-/- mice in a needle puncture-induced knee-joint bleeding model. Additionally, we found that HAPC1573 significantly improved the thrombin generation of PROC+/+;F8-/- mice but not F8-/- mice, indicating that HAPC1573 enhanced the coagulant activity of hemophilia mice by modulating human APC in vivo. We further documented that HAPC1573 inhibited the APC anticoagulant activity to improve the clotting time of human plasma deficient of FVIII, FIX, FXI, FVII, VWF, FV, or FX. These results demonstrate that selectively blocking the anticoagulant activity of human APC may be an effective therapeutic and/or prophylactic approach for bleeding disorders lacking FVIII, FIX, or other clotting factors.

[Research Progress on the Mechanism of Tubulin in Megakaryopoiesis and Regulation of Platelet Count--Review].

Tubulin affects platelets count through the control of mitosis and the formation of pro-platelets during the maturation of megakaryoblast to platelets. Tubulin is involved in maintaining the integrity of platelet skeleton, and also participates in the change of platelet morphology during platelet activation. Some new anti-tumor drugs targeting cell mitosis are trying to reduce the effect on tubulin in order to reduce the side effect of drugs on platelet formation. In some patients with thrombocytopenia, the variation and polymorphism of the tubulin gene affect the structure of microtubule multimers, which leads to the decrease of platelet formation. This review summarized the latest progresses of tubulin in the regulation of megakaryopoiesis and thrombopoiesis.

Ticagrelor versus Clopidogrel in CYP2C19 Loss-of-Function Carriers with Stroke or TIA.

BACKGROUND: Comparisons between ticagrelor and clopidogrel for the secondary prevention of stroke in CYP2C19 loss-of-function carriers have not been extensively performed. METHODS: We conducted a randomized, double-blind, placebo-controlled trial at 202 centers in China involving patients with a minor ischemic stroke or transient ischemic attack (TIA) who carried CYP2C19 loss-of-function alleles. Patients were assigned within 24 hours after symptom onset, in a 1:1 ratio, to receive ticagrelor (180 mg on day 1 followed by 90 mg twice daily on days 2 through 90) and placebo clopidogrel or to receive clopidogrel (300 mg on day 1 followed by 75 mg once daily on days 2 through 90) and placebo ticagrelor; both groups received aspirin for 21 days. The primary efficacy outcome was new stroke, and the primary safety outcome was severe or moderate bleeding, both within 90 days. RESULTS: A total of 11,255 patients were screened and 6412 patients were enrolled, with 3205 assigned to the ticagrelor group and 3207 to the clopidogrel group. The median age of the patients was 64.8 years, and 33.8% were women; 98.0% belonged to the Han Chinese ethnic group. Stroke occurred within 90 days in 191 patients (6.0%) in the ticagrelor group and 243 patients (7.6%) in the clopidogrel group (hazard ratio, 0.77; 95% confidence interval, 0.64 to 0.94; P = 0.008). Secondary outcomes were generally in the same direction as the primary outcome. Severe or moderate bleeding occurred in 9 patients (0.3%) in the ticagrelor group and in 11 patients (0.3%) in the clopidogrel group; any bleeding occurred in 170 patients (5.3%) and 80 patients (2.5%), respectively. CONCLUSIONS: Among Chinese patients with minor ischemic stroke or TIA who were carriers of CYP2C19 loss-of-function alleles, the risk of stroke at 90 days was modestly lower with ticagrelor than with clopidogrel. The risk of severe or moderate bleeding did not differ between the two treatment groups, but ticagrelor was associated with more total bleeding events than clopidogrel. (Funded by the Ministry of Science and Technology of the People's Republic of China and others; CHANCE-2 ClinicalTrials.gov number, NCT04078737.).

Analytical validation of GMEX rapid point-of-care CYP2C19 genotyping system for the CHANCE-2 trial.

BACKGROUND AND PURPOSE: Rapid genotyping is useful for guiding early antiplatelet therapy in patients with high-risk nondisabling ischaemic cerebrovascular events (HR-NICE). Conventional genetic testing methods used in CYP2C19 genotype-guided antiplatelet therapy for patients with HR-NICE did not satisfy the needs of the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE)-2 trial. Therefore, we developed the rapid-genotyping GMEX (point-of-care) system to meet the needs of the CHANCE-2 trial. METHODS: Healthy individuals and patients with history of cardiovascular diseases (n=408) were enrolled from six centres of the CHANCE-2 trial. We compared the laboratory-based genomic test results with Sanger sequencing test results for accuracy verification. Next, we demonstrated the accuracy, timeliness and clinical operability of the GMEX system compared with laboratory-based technology (YZY Kit) to verify whether the GMEX system satisfies the needs of the CHANCE-2 trial. RESULTS: Genotypes reported by the GMEX system showed 100% agreement with those determined by using the YZY Kit and Sanger sequencing for all three CYP2C19 alleles (*2, *3 and *17) tested. The average result's turnaround times for the GMEX and YZY Kit methods were 85.0 (IQR: 85.0-86.0) and 1630.0 (IQR: 354.0-7594.0) min (p<0.001), respectively. CONCLUSIONS: Our data suggest that the GMEX system is a reliable and feasible point-of-care system for rapid CYP2C19 genotyping for the CHANCE-2 trial or related clinical and research applications.

Construction of core-shell structured WO3@SnS2 hetero-junction as a direct Z-scheme photo-catalyst.

An ideal photocatalyst not only offers high photo-generated electron-hole pairs separation ability, but also has suitable redox potential. Here, a direct Z-scheme core-shell structured WO3@SnS2 hetero-junction photo-catalyst was prepared via two-step hydrothermal method, in which the core-shell structure, rod morphology and micro-composition of hetero-junction were confirmed through X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) spectra, field emission scanning electron microscope (FE-SEM), transmission electron microscope (FEI-TEM) and X-ray photoelectron spectra (XPS). Their enhanced photo-catalytic abilities were evaluated by photo-degradation of Rhodamine (RhB), photo-reduction of dichromate (Cr6+) solution and photo-catalytic H2 production through comparing with pure WO3, SnS2 or the mixture of WO3 and SnS2 (WO3/SnS2). The absorption spectra and electrochemical properties were used to estimate the band gap of samples, the expanded spectral absorption capacity and improved electron-hole separation ability, which are important factors for enhanced photocatalytic performance. Furthermore, the direct Z-scheme charge transfer mechanism of WO3@SnS2 hetero-junction was determined through the combination of theoretical calculation and experimental characterizations, which played a decisive role for retaining excellent redox potential and increasing photo-catalytic ability of WO3 and SnS2.