bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrite Regulation Of Platelet Reactivity Under Physiological Conditions
Authors: Park Ji Won , Piknova Barbora , Nghiem Khanh , Lozier Jay N. , Schechter Alan N. 
Published: October 2019

Nitric oxide (NO) is generated by serial reduction pathway of nitrate and nitrite or by activity of endogenous nitric oxide synthase (NOS), and modulates platelet function and hemostasis. We have shown by aggregometry and flow cytometric analysis of P-selectin that nitrite in the presence of erythrocytes inhibits platelet aggregation and activation after its reduction to NO at low oxygen tension [PLoS One. 2012; 7: e30380. 10.1371/journal.pone.0030380]. We then investigated how nitrite may affect overall clotting processes by regulating platelet function using thrombelastography (TEG), a method used to assess platelet function, fibrin clot formation, and fibrinolysis in blood and/or plasma. We measured the effect of NO donors and nitrite on three TEG parameters, reaction time (R, time to initial fibrin formation), α angle (velocity of clot growth) and maximum amplitude (MA, clot strength), in healthy volunteers. The NO donor (DEANONOate) inhibited all three TEG parameters in response to two independent platelet activators (ADP and AA), in platelet rich plasma (PRP) or whole blood diluted with plasma to yield 20% hematocrit (Hct) to model blood in the microcirculation in vivo. At DEANONOate concentrations ranging from 0-1 μM, R values were progressively prolonged from 1.9 to 3.6 (p=0.008), α angle was decreased from 17.8 to 9.5 (p=0.01) and maximum clot amplitude was reduced from 9.0 to 4.4 (p=0.001) in 20% Hct with ADP stimulation. In contrast, nitrite did not affect clotting parameters in PRP, but exhibited moderate inhibitory effects in 20% Hct at concentrations from 0-10 μM; R values were slightly prolonged from 1.6 to 2.7 (p=0.12), α angle was decreased from 21.8 to 12.8 (p=0.07) and maximum clot amplitude was reduced from 11.0 to 5.0 (p=0.02). This inhibitory effect of nitrite on clotting was greatly enhanced under hypoxic conditions (blood pO2 46.5±11.6 mmHg); R values from 1.4 to 4.0 (p=0.003), α angle from 21.7 to 7.8 (p=0.002), and maximum clot amplitude from 10.0 to 3.4 (p=0.0003). These results suggest that the nitrite effect may be greatest in the microcirculation and be important in differences between arterial and venous clotting. In conclusion, our results show TEG parameters indicate NO inhibition of platelet-mediated blood clotting and that the physiological effect of factors which determine NO bioavailability, such as reduction of blood and tissue nitrite, could be used to predict hemostasis.

Disclosures:
Schechter: National Institutes of Health: Dr. Alan Schechter is listed as a co-inventor on several patents issued to the National Institutes of Health for the use of nitrite salts for the treatment of cardiovascular diseases., Dr. Alan Schechter is listed as a co-inventor on several patents issued to the National Institutes of Health for the use of nitrite salts for the treatment of cardiovascular diseases. Patents & Royalties.
A Case Of Vitamin C Deficiency Manifesting With Easy Bruising: Suggestion For a Supplementation Protocol
Authors: Zaidi Aisha , Moffett Padmini 
Published: October 2019

Contrary to most animals which are capable of obtaining ascorbic acid (vitamin C) by metabolizing glucose, humans require an exogenous source of vitamin C. It is a water-soluble vitamin found in various foods, including citrus fruits (oranges, lemons, grapefruit), green vegetables (peppers, broccoli, cabbage), tomatoes, and potatoes. It is essential for growth and repair of tissues, particularly blood vessels. Deficiency of vitamin C is relatively rare; the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994) found approximately 13% of the US population to be vitamin C deficient. Smoking cigarettes lowers the amount of vitamin C in the body, so smokers are at a higher risk of deficiency. Additionally, alcoholics, the elderly, patients with psychiatric disorders and individuals who experience social isolation are also at risk. Symptoms can manifest after 3 months of deficient intake of vitamin C -containing foods. Since ascorbic acid is required for collagen synthesis, deficiency usually manifests with bleeding gums, ecchymoses, petechiae, coiled hairs and hyperkeratosis. Diagnosis can be established when plasma levels of vitamin C fall below 0.2mg/dl. There are currently no evidence based guidelines for supplementation once low levels are detected. We describe a case of a 33 year old Caucasian female seen in our clinic for easy bruising of 10 years duration. She would wake up in the morning with bruised arms and legs without any inciting trauma. She denied prolonged bleeding after dental extractions, frequent nose bleeds, menorrhagia any genitounrinary or gastrointestinal blood loss. Her exam revealed ecchymoses on her arms and legs with no evidence of perifollicular hemorrhage or gingival hyperplasia. Workup including CBC, Coagulation profile and Von Willibrand factor levels were all within normal limits. She had a vitamin C level of 0.1mg/dl. She was subsequently advised to increase vitamin C intake through fruits and vegetable and was started on vitamin C supplementation with 500mg twice a day for four weeks. Her repeat vitamin C level on her one month follow up was noted to be 1.9mg/dl. She noticed complete resolution of her symptoms. This case illustrates the fact that vitamin C deficiency should be excluded in adults presenting with bruising. It also offers a supplementation regimen that resulted in improvement of clinical symptoms as well as laboratory value normalization.

Disclosures:
No relevant conflicts of interest to declare.
Acquired Hemophilia A. Experience Of a Single Center
Authors: Alzate Mauricio A , Meschengieser Susana S , Blanco Alicia , Grosso Silvia , Lazzari María A , Sánchez-Luceros Analía 
Published: October 2019

Introduction
Acquired hemophilia A is a rare and serious autoimmune disease. Morbidity and mortality are associated with advanced age, comorbidities, toxicity of treatment and bleeding severity. Treatment goals are control of the bleeding and eradication of the inhibitor, while treating the underlying condition if it is present.

Objective
To describe the baseline characteristics of acquired hemophilia A patients and to assess the response to treatment.

Patients and Methods
Between November 1991 and April 2013, 27 patients were diagnosed with acquired hemophilia A (mean age 59, range 21-86; 18 women - 66%) in the Departamento de Hemostasia y Trombosis. Five patients were lost from follow-up. APTT mixing studies with normal plasma (1:1) and time-temperature dependent effect on the APTT were performed for a-FVIII diagnosis. Whenever possible, inhibitor activity was titrated by Bethesda method at diagnosis (BU/mL). Medical records were reviewed to evaluate the initial symptoms, underlying diseases, treatments and outcome.

Results
The mean follow-up was 86 weeks (range 1-640). Underlying etiologies included: idiopathic 70.4%, postpartum 14.8%, malignancy 11.1%, autoimmune disease 3.7%. All patients had bleeding at diagnosis. The most frequent sites of bleeding were: muscular 32%, soft tissue 18%, urinary tract 9%, gastrointestinal tract 6%; being from multiple sites in 9%. At diagnosis, the mean value for FVIII was 6% (range 1-40), and inhibitor titer 220 BU/mL (range 2.2-1173). Initial therapeutic scheme included glucocorticoids in 97% of the patients, 13 in monotherapy (mean age 53 years ± 19), 13 with cyclophosphamide (63 years ± 18) (p= ns), and human immunoglobulin in 1 patient. This last patient died after 1 week of diagnosis due to uncontrolled gastrointestinal bleeding (previous to the era of rVIIa). As a second-line therapy, rituximab was used in 3 patients.
Sixty-three (63%) patients achieved complete response (CR) (inhibitor titer < 0.6 BU/mL without bleeding episodes), and 23% achieved partial response (PR) (reduction in inhibitor titer > 50% without bleeding episodes), without differences between monotherapy or combined. Overall, women responded more frequently than men (93.3% vs. 71.4%, p= ns). All patients that received rituximab achieved CR.

Conclusions
In this study, the overall response rate was higher than 80%. In most cases, the disease has a prolonged course like other autoimmune diseases, with remissions and relapses.

Disclosures:
No relevant conflicts of interest to declare.
Dysregulation Of Thrombotic and Hemostatic Factors In End Stage Renal Disease
Authors: Bansal Vinod , Hoppensteadt Debra , Ahmed Syed , Fareed Jawed 
Published: October 2019

Introduction
Increased cardiovascular events occur in ESRD patients on maintenance hemodialysis. The objective of this study was to utilize newly introduced cardiac biomarker chips and immunoenzymatic methods, profiling various biomarkers of inflammation and thrombogenesis in a defined ESRD patient population.

Material and Methods
Blood samples from seventy two ESRD patients were drawn prior to maintenance hemodialysis. Commercially available ELISA kits for Tissue Plasminogen Activator – Plasminogen Activator Inhibitor Type-1 complex (tPA-PAI-1 complex), Plasminogen Activator Inhibitor Type-1 (PAI-1), Myeloperoxidase, (MPO), Thrombomodulin, (TM), Interleukin-1 beta (IL-1β), Anti-Annexin V, human sL-selectin, and Inter-Cellular Adhesion Molecule 1 (ICAM-1). Functional methods were used for measuring Antithrombin and Von Willebrand factor (vWF) activity were used. The biochip arrays (Randox, Evidence System, United Kingdom)for cardiac markers, included creatine kinase-MB (CK-MB), Myoglobin (Myo), Heart-type fatty acid binding protein (hFABP) and cardiac troponin I (cTn1). The cerebral array included C-reactive protein (CRP), D-Dimer (DDMER), Neuron Specific Enolase (NSE), Neutrophil Gelatinase-Associated Lipocalin (NGAL), soluble Tumor Necrosis Factor Receptor 1 (TNFRI) and Thrombodulin (TM).

Results
ESRD patients showed assay dependent decrease in markers such as tPA-PAI-1, Anti-Annexin V, L-selectin and Antithrombin activity (ranging from 18 to 46%). The levels for MPO, TM, CK-MB, MYO, FABP, CRP, DDMER, NSE, NGAL, TNFR1, and vWF activity all showed a significant increase in the ESRD patients (ranging from 25%-5587%). No changes were observed in the IL-1B, ICAM1, or cTn1 in ESRD patients compared to normal groups.

Conclusions
These studies underscore the role of inflammatory and thrombotic mediators in ESRD. The cardiac biochip array revealed a remarkable elevation of the FABP and as well as a notable increase in MYO. The cerebral array revealed a remarkable elevation of the TNFR1.

Disclosures:
No relevant conflicts of interest to declare.
Molecular Analysis Of Patients With Deep Venous Thrombosis
Authors: Hosseeini Soudabeh , Kalantari Ebrahim , Dorgalaleh Akbar , Rozei Arash , Jafari Marzieh , Naderi Majid , Tabibian Shadi , Bamedi Taregh 
Published: October 2019

Background
Deep venous thrombosis (DVT) refers to the formation of a thrombus within a deep vein that frequently occurs after surgical procedures, trauma, in the presence of cancer and immobilization conditions. DVT is a major health problem that causes high rate of morbidity and mortality in the general population. Hyper coagulation states such as antithrombin-III, protein-C and protein-S deficiencies, contribute to formation of DVT.
Congenital and acquired gene mutations are other risk factors that stimulate formation of thrombus. Our aims in this study was to molecularly analyze the patients with DVT and assess the impact of common mutations of MTHFR (C677T) (A1298C), PAI-1, Prothrombin 20210 and FV Leiden mutation on occurrence of deep venous thrombosis.

Methods
This long-term study was conducted from June 2009 to July 2013 on 221 patients with deep venues thrombosis. Two hundred and twenty-one age and sex matched individuals were also chosen as control group. The diagnosis of venous thromboembolic disease was based on patient’s history, clinical findings and D-dimer test. Finally deep venous thrombosis was confirmed with Doppler ultrasonography. In addition, all participants were asked to complete a standardized questionnaire on acquired risk factors for venous thrombosis.
After confirmation of DVT, both groups were assessed molecularly for five mutations including, MTHFR C677T, MTHFR A1298C, PAI-1 4G/5G, Prothrombin 20210 and FV Leiden. The relationship between these mutations and the risk of DVT was calculated using logistic regression and expressed as an OR with a 95% confidence interval (CI).

Results
The mean age of patients and control group were 38±0.8 and 3.7± 0.7 years. Our results revealed that the MTHFR C677T (OR 2.9, 95% 95% CI 1.1 to 7.5) and MTHFR A1298C in heterozygote manner (OR 4.3, 95% CI 1.4 to 13.7) were each associated with an increased risk of DVT. The OR associated with being a carrier of the PAI-1 4G/5G genotype was 2.9 (95% CI 1.14 to 7.5). There was a 4-fold increased risk of DVT associated with Prothrombin 20210 mutation in heterozygote manner (OR 4.3, 95% CI 1.4 to 13.7).
For patients who were heterozygous for FV Leiden mutation OR DVT was 2.6 (95% CI 1.3 to 5.0).

Conclusion
Our findings suggest that genetic risk factors have a contributory role on occurrence of DVT.

Disclosures:
No relevant conflicts of interest to declare.
Thrombolytic properties of staphylokinase
Authors: Matsuo O , Okada K , Fukao H , Tomioka Y , Ueshima S , Watanuki M , Sakai M 
Published: October 2019

Abstract
We evaluated the properties of recombinant staphylokinase in comparison with those of tissue-type plasminogen activator (t-PA) and streptokinase (SK). The presence of fibrin(ogen) fragment FCB-2 in the reaction mixture increased plasminogen activation by staphylokinase more than 20-fold. Such characteristics are similar to those of t-PA. On the other hand, SK was not affected by the presence of FCB-2. The thrombolytic properties of staphylokinase were studied in a system consisting of a radioactive human plasma clot (125I-fibrinogen-labeled) suspended in the circulating citrated plasma. Significant thrombolysis (50% in 3 hours) was obtained with 2 micrograms/mL of staphylokinase and 4.45 micrograms/mL t-PA, as compared with 12 micrograms/mL for SK. The relative molar potency of staphylokinase, calculated from the molecular weight, was about two times more effective than that of SK, but about half of that of t-PA. Systemic fibrinolytic activation and fibrinogen breakdown was not observed with staphylokinase or t-PA, but was observed with SK. The thrombolytic efficiency of staphylokinase, which was calculated as the ratio of the degree of thrombolysis/the degree of fibrinogenolysis, was about five times greater than that of SK, and about half of that of t-PA. These findings suggest that staphylokinase has higher specific thrombolytic properties and lesser fibrinogenolytic properties than those of SK.
Multidrug resistance (mdr1) gene expression in adult acute leukemias: correlations with treatment outcome and in vitro drug sensitivity
Authors: Marie JP , Zittoun R , Sikic BI 
Published: October 2019

Abstract
Resistance to multiple chemotherapeutic agents has been related to the production of P-glycoprotein, a trans-membrane drug efflux pump that is encoded by the multidrug resistance (MDR) gene mdr1. To investigate whether mdr1 could be involved in clinical resistance to chemotherapy in acute leukemias, we have analyzed retrospectively the RNA from adult acute leukemia cells by slot-blot hybridization with a human mdr1 probe. Units of mdr1 expression were defined by reference to drug- sensitive human sarcoma and K562 leukemia cell lines (1 U) and the highly resistant doxorubicin selected leukemia cells K562/R7 (50 U). We studied 41 adult patients with acute leukemias: 5 acute lymphoblastic leukemias, 23 acute myeloid leukemias, and 13 secondary leukemias or blast crisis of chronic myelogenous leukemia. Expression of 10 U or more of mdr1 was found in 6 of 31 (19%) leukemias at diagnosis, versus 5 of 10 (50%) after relapse from therapy, P = .06. The complete remission rate and in vitro sensitivity to daunorubicin were both correlated with low expression (1 U, v 2 U or more) of mdr1. Among 36 evaluable attempts to induce remission, the complete remission rate was 67% (8 of 12) for patients with undetectable or minimal mdr1 expression (1 U), versus 29% (7 of 24) in patients with 2 U or more of expression, P = .03. In vitro resistance to daunorubicin or other MDR-related drugs was associated with expression of 2 U or more of mdr1 in 11 of 11 cases, while specimens that were sensitive to these agents were negative for mdr1 expression in 5 of 11 cases, P = .03. These data suggest that mdr1 expression contributes to chemoresistance in acute leukemia. Determination of mdr1 gene expression may be useful in designing therapy for patients with leukemia.
Dihydrotestosterone exerts a depressive influence on the production of interleukin-4 (IL-4), IL-5, and gamma-interferon, but not IL-2 by activated murine T cells
Authors: Araneo BA , Dowell T , Diegel M , Daynes RA 
Published: October 2019

Abstract
The present study examined the effects of the androgen steroid, dihydrotestosterone (DHT), on murine T-cell production of a number of lymphokines. Direct exposure of murine T cells to DHT in vitro was found to reduce the amount of interleukin-4 (IL-4), IL-5, and gamma- interferon (gamma IFN) produced after activation with anti-CD3 without affecting the production of IL-2. Exposure of T cells to either androstenedione or testosterone (the metabolic precursors of DHT) affected no change in the biosynthesis of either of these lymphokines. We have determined that macrophages possess 5 alpha-reductase, and are thus competent to metabolize testosterone to DHT. This physicochemical information is complemented by a functional analysis of macrophage metabolism of testosterone. By incubating bone marrow macrophages with testosterone, before their use as accessory cells, the IL-4 and IL-5 producing potential of the activated T cells cocultured with them was depressed. That the observed effect was mediated by the conversion of testosterone to DHT was further corroborated by illustrating that the inhibition of IL-4 production was abrogated if 4MA, a specific 5 alpha- reductase inhibitor, was added to macrophage cultures containing testosterone. The biologic role of DHT in lymphokine and immune response regulation in vivo was addressed using several lines of investigation. First, transdermal delivery of DHT to groups of mice altered the capacity of T cells residing in the draining lymph nodes, only, to produce lymphokines. Second, treatment of either aged mice or the T cells isolated from them with a combination of dehydroepiandrosterone and DHT restored the capacity of their T cells to produce IL-2, IL-4, and gamma IFN to levels equivalent to that of younger mice. Finally, we observed a difference between males and females of a given age to produce IL-2, IL-4, and gamma IFN, with both IL-4 and gamma IFN production being elevated in females. Collectively, our findings indicate that DHT, similar to other steroid hormones, may play an important role in lymphokine regulation in vivo.
The t(1;22) (p13;q13) is nonrandom and restricted to infants with acute megakaryoblastic leukemia: a Pediatric Oncology Group Study
Authors: Carroll A , Civin C , Schneider N , Dahl G , Pappo A , Bowman P , Emami A , Gross S , Alvarado C , Phillips C 
Published: October 2019

Abstract
We report the nonrandom occurrence and frequency of the t(1;22)(p13;q13) in acute myeloid leukemia (AML) and its close association with the French-American-British M7 subtype of AML in infants (less than 1 year). This chromosomal abnormality occurred in 6 of 252 (2.4%) children and adolescents with AML (6 of 28 infants, 22%; 6 of 18 M7 AML cases overall, 33%; and 6 of 6 M7 cases in infants). Infants with AML of M7 subtype and the t(1;22) often presented with prominent abdominal masses. Two of these infants were not treated and died early. Three of four treated infants entered complete remission with therapy for AML; the remaining infant died of hemorrhage on day 8. Of the three infants who entered remission, only one remains alive and disease free at 5+ months. The other two infants relapsed in the bone marrow at 5 and 2 months from the start of therapy, respectively. We conclude that M7 AML with the t(1;22) usually presents in infants with extensive infiltration of abdominal organs by leukemic cells and may confer a poor prognosis despite intensive AML-directed treatment. Identification of this nonrandom translocation exclusively in infants with acute megakaryoblastic leukemia (AMkL) implies that it may serve as an additional diagnostic marker for this disease and links it to the pathogenesis of AMkL in infants.
Inhibition of human platelet reactivity by endothelium-derived relaxing factor from human umbilical vein endothelial cells in suspension: blockade of aggregation and secretion by an aspirin-insensitive mechanism
Authors: Broekman MJ , Eiroa AM , Marcus AJ 
Published: October 2019

Abstract
To determine a role for endothelium-derived relaxing factor/nitric oxide (EDRF/NO) in regulation of human platelet reactivity by human endothelial cells (EC), we studied combined suspensions of human umbilical vein endothelial cells (HU-VEC, passage 2 through 3) and washed human platelets. Confluent HUVEC monolayers were treated with aspirin (1 mmol/L) to prevent prostacyclin (PGI2) formation, washed, and harvested. Aspirin-treated platelets alone (58 x 10(6)) were fully aggregated by thrombin at 0.05 U/mL or more. In the presence of 10(6) HUVEC, however, platelet serotonin release and aggregation in response to thrombin at doses as high as 0.5 U/mL were blocked. We demonstrated for the first time that inhibition of aggregation and serotonin release, due to EDRF/NO, occurred in parallel. HUVEC-dependent inhibition of platelet responsiveness was enhanced by superoxide dismutase (SOD) and reversed by hemoglobin. The inhibitory effect was also reversed by preincubation of HUVEC with NG-monomethyl-L-arginine (NMA) or NG-nitro-L-arginine (NNA) through competitive blockade of arginine metabolism. Pretreatment of platelets with methylene blue indicated that EC-dependent inhibition of platelet reactivity occurred through activation of platelet soluble guanylate cyclase. When platelets and HUVEC were separated by a permeable membrane and both cells were stimulated by thrombin, platelets remained unresponsive. This indicated that inhibition was induced by a fluid-phase mediator, independent of direct cell-cell contact. These data demonstrate that EDRF/NO formation from L-arginine by human EC plays an important role as an aspirin-insensitive fluid-phase inhibitor of human platelet reactivity.