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The World Health Organization framework for tracking SARS-CoV-2 variants has been updated to reflect the continued evolution of the virus; this framework could be adapted for other emerging respiratory diseases with epidemic and pandemic potential.

Global sequencing and surveillance capacity for SARS-CoV-2 must be strengthened and combined with multidisciplinary studies of infectivity, virulence and immune escape, in order to track the unpredictable evolution of the ongoing COVID-19 pandemic.

•Short-term fixed-dose isoquercetin did not lower plasma soluble P-selectin in adults with steady-state SCD.•Isoquercetin treatment attenuated blood coagulation, platelet aggregation, and inducible tissue factor gene expression in adults with SCD.

ABSTRACTFour seronegative foals aged 6 to 7 months were exposed to an aerosol of influenza strain A/Equi/2/Kildare/89 at 10650% egg infective doses (EID50)/ml. Nasopharyngeal swabs were collected for 10 consecutive days after challenge. Virus isolation was performed in embryonated eggs, and the EID50was determined for all positive samples. The 50% tissue culture infective dose was determined using Madin-Darby canine kidney (MDCK) cells. Samples were also tested by an in vitro enzyme immunoassay test, Directigen Flu A, and by reverse transcription-PCR (RT-PCR) using nested primers from the nucleoprotein gene and a single set of primers from the matrix gene. RT-PCR using the matrix primers and virus isolation in embryonated eggs proved to be the most sensitive methods for the detection of virus. The Directigen Flu A test was the least sensitive method. The inclusion of 2% fetal calf serum in the viral transport medium inhibited the growth of virus from undiluted samples in MDCK cells but was essential for the maintenance of the virus titer in samples subjected to repeated freeze-thaw cycles.

Pulmonary arterial hypertension is characterized by endothelial dysfunction and microthrombi formation. The role of anticoagulation remains controversial, with studies demonstrating inconsistent effects on pulmonary arterial hypertension mortality. Clinical anticoagulation practices are currently heterogeneous, reflecting physician preference. This study uses thrombelastography and hematology markers to evaluate whether clot formation and fibrinolysis are abnormal in pulmonary arterial hypertension patients. Venous blood was collected from healthy volunteers (n= 20) and patients with pulmonary arterial hypertension (n= 20) on stable medical therapy for thrombelastography analysis. Individual thrombelastography parameters and a calculated coagulation index were used for comparison. In addition, hematologic markers, including fibrinogen, factor VIII activity, von Willebrand factor activity, von Willebrand factor antigen, and alpha2-antiplasmin, were measured in pulmonary arterial hypertension patients and compared to healthy volunteers. Between group differences were analyzed using t tests and linear mixed models, accounting for repeated measures when applicable. Although the degree of fibrinolysis (LY30) was significantly lower in pulmonary arterial hypertension patients compared to healthy volunteers (0.3% ± 0.6 versus1.3% ± 1.1, p= 0.04), all values were within the normal reference range (0–8%). All other thrombelastography parameters were not significantly different between pulmonary arterial hypertension patients and healthy volunteers (p≥ 0.15 for all). Similarly, alpha2-antiplasmin activity levels were higher in pulmonary arterial hypertension patients compared to healthy volunteers (103.7% ± 13.6 versus82.6% ± 9.5, p< 0.0001), but all individual values were within the normal range (75–132%). There were no other significant differences in hematologic markers between pulmonary arterial hypertension patients and healthy volunteers (p≥ 0.07 for all). Sub-group analysis comparing thrombelastography results in patients treated with or without prostacyclin pathway targeted therapies were also non-significant. In conclusion, treated pulmonary arterial hypertension patients do not demonstrate abnormal clotting kinetics or fibrinolysis by thrombelastography.

A library of the equine herpesvirus 4 (EHV-4) genome was constructed in the λgt11 expression vector. Recombinant bacteriophage expressing EHV-4 antigens as beta-galactosidase fusion proteins were detected with rabbit antiserum raised against EHV-4 virions and convalescent horse serum. EHV-4 DNA sequences contained in the immunopositive recombinants were used as hybridization probes for mapping the genes encoding the antigens on the viral genome. The DNA sequence of the probes was determined. Screening the library with rabbit antiserum led to the identification of 40 recombinants, 26 of which were further characterized. Determination of the DNA sequence of the EHV-4 inserts revealed that 23 of the recombinants encode an identical portion of glycoprotein gB. Two of the recombinants encode a portion of the previously unidentified EHV-4 homologue of the EHV-1 immediate early protein. The EHV-4 insert of the remaining recombinant encodes a portion of the previously unidentified EHV-4 homologue of herpes simplex virus 1 (HSV-1) UL36, a tegument protein. Screening the library horse serum led to the identification of three recombinants, one of which encodes the same gB sequence as the gB recombinant recognized with the rabbit serum. The other two contain overlapping sequences that encode a portion of EHV-4 gX.

ABSTRACTEquine influenza is a cause of epizootic respiratory disease of the equine. The detection of equine influenza virus using real-time Light Cycler reverse transcription (RT)-PCR technology was evaluated over two influenza seasons with the analysis of 171 samples submitted for viral respiratory disease. Increased sensitivity was found in overall viral detection with this system compared to Directigen Flu A and virus isolation, which were 40% and 23%, respectively, that of the RT-PCR. The assay was also evaluated as a viable replacement for the more traditional methods of quantifying equine influenza virus, 50% egg infectious dose and 50% tissue culture infectious dose. There was a significant positive correlation (P< 0.05) between the quantitative RT-PCR and both of these assays.

Abstract:  Cancer patients with venous access devices (VADs) often receive daily flushes of heparin. Even this relatively small heparin exposure has been reported to induce immune-mediated thrombocytopenia. To estimate how frequently this occurs we tested for heparin-related antibodies in 49 patients receiving daily heparin flushes of their VADs. Although one-third of the patients showed evidence of heparin sensitization on at least one occasion during their surveillance, their antibody titers were generally low and typical of those found in other cohorts of patients who become sensitized to heparin but do not develop secondary thrombocytopenia. However, one patient developed a positive serotonin release assay indicative of a more significant sensitization, but without thrombocytopenia. Therefore, our observations suggest that heparin-induced thrombocytopenia (HIT) related to heparin flushes of VADs is uncommon but still an important diagnosis to entertain.

Background:Pulmonary arterial hypertension (PAH) is characterized by endothelial dysfunction and microthrombi formation. The role of anticoagulation remains controversial with prospective and retrospective studies showing conflicting results on PAH mortality. Current clinical practice reflects physician preference. This study uses thrombelastography (TEG) and hematology markers associated with coagulation to evaluate whether the process of clot formation and fibrinolysis is abnormal in PAH.Methods:An NIH institutional review board approved the protocol and participants provided written informed consent. For all testing, no subjects were on anticoagulation or antiplatelet agents. Venous blood was collected into a sodium citrate tube for 17 healthy controls and 20 PAH patients. A TEG 5000 Hemostasis Analyzer (Haemonetics, Braintree, MA, USA) was used to perform the kaolin-activated assay. TEG parameters included R (time to initiate clot formation), K (time to reach a clot strength of 20 mm), alpha (speed of fibrin cross-linking), MA (maximum amplitude of clot strength), G (shear elastic modulus strength), and LY30 (degree of fibrinolysis at 30 min). Additional hematology markers, including fibrinogen, factor VIII activity, von Willebrand (vWF) activity, vWF antigen, and alpha2-antiplasmin (?2AP), were measured on all controls (n = 17) and at multiple time points on 18 of the PAH TEG subjects and 3 additional PAH patients (n = 35).Results:TEG parameters were not statistically different between controls versus patients, including R (6.88?0.34 vs 5.89?0.26 min), K (1.64?0.07 vs 1.63?0.16 min), alpha (66.5?0.9 vs 66.4?1.6 degrees), MA (65.6?0.9 vs 65.0?1.4 mm), G (9.68?0.34 vs 9.75?0.66 Kd/sc), and LY30 (1.30?0.28 vs 0.73?0.29 %). Compared to controls, PAH patients had elevated ?2AP (83.2?1.3 vs 91.1?3.3 %; P = 0.04) while other markers were similar.Conclusion:PAH patients do not demonstrate abnormal clotting kinetics or fibrinolysis by kaolin TEG. Alpha2-antiplasmin, which has been correlated with vascular remodeling, thrombosis, and fibrosis, is increased in PAH. The mechanism by which anticoagulation may benefit PAH patients could be through a protective effect against microthrombi formation due to endothelial dysfunction.

Off Label Use: Lenalidomide is not FDA approved for chronic lymphocytic leukemia..

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