bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non-Heme Induction of HO-1 in Macrophages Does Not Apparently Alter Cellular Iron Levels.
Authors: Sheftel Alex D. , Kim Sangwon F. , Ponka Premysl 
Published: October 2019

Abstract
The catabolism of heme is carried out by members of the heme oxygenase (HO) family. The predominant isozyme in the digestion of erythroid heme is the inducible form, HO-1. The products of heme catabolism by HO-1 are ferrous iron, biliveridin (subsequently converted to bilirubin), and carbon monoxide (CO). In addition to its function in the recycling of erythrocyte iron, this microsomal enzyme has been implicated in a number of cytoprotective mechanisms mainly in the context of oxidant insult. HO-1 can be induced not only by heme, but also by cytokines, heat shock, metals, and other cellular stressors, especially those that generate reactive oxygen species (ROS). Implicit in all the reports of HO-1 cytoprotection to date are effects on the cellular handling of heme and , therefore, iron. While bilirubin is an antioxidant, ferrous iron is known to catalyze the production of hydroxyl radicals through Fenton chemistry. Thus, the release of iron from heme could be counterproductive in protecting the cell from oxidative stress. Furthermore, there are a number of non-heme stimulators of HO-1 induction, bringing to question the source of substrate for this enzyme in these paradigms. In the present study, HO-1 was induced by either sodium arsenite or hemin in the murine macrophage-like cell line, RAW264.7. Both of these inducers elicited a transient increase in both the mRNA and protein levels of HO-1, however, only hemin exposure induced an increase in the synthesis rate of the iron storage protein, ferritin. This increase in ferritin production rate, as measured by 35S-methionine incorporation, was attenuated by the HO inhibitor, tin-protoporphyrin IX (SnPP) as well as the cell permeable iron chelator, salicylaldehyde isonicotinoyl hydrazone (SIH). Additionally, treatment of the cells with hemin was able to elicit a decrease in the activity of iron regulatory proteins (IRPs) that could be blocked by preincubation with SnPP. Sodium arsenite had no effect on IRPs. These results suggest that iron released from hemin by HO-1 stimulates ferritin synthesis via the IRE/IRP system, while an increase in the enzyme via a non-heme inducer does not lead to iron release from endogenous heme sources.
Myocardial Infarction Induced by Intravenous Iron Dextran Infusion in Absence of Coronary Artery Disease.
Authors: Ahluwalia Manmeet S. , Patel Sandeep , Daw Hamed 
Published: October 2019

Abstract
A 37-year-old-female presented with history of fatigue for 2–3 months and excessive vaginal bleeding. Further evaluation of the patient revealed iron deficiency anemia secondary to blood loss because of dysfunctional uterine bleeding. She was scheduled for intravenous (IV) iron dextran infusion because of her inability to tolerate oral iron. The possible risks were explained to the patient who decided to proceed with the infusion. Immediately after the infusion the patient developed anaphylactic type reaction and complained of severe chest pain and shortness of breath. Electrocardiogram (EKG) done did not show any evidence of ST changes suggestive of ischemia. However her troponin was elevated at 2.7 (0–0.25). Patient underwent a cardiac catheterization that did not show any evidence of coronary artery disease (CAD). There was however mild impairment of left ventricular systolic function with severe hypokinesis of the apex and distal anterior and anterolateral wall with ejection fraction of around 45 %. Patient most likely developed a non-ST elevation myocardial infarction (MI) secondary to IV iron-dextran induced anaphylactic reaction and hypotension. She was treated with steroids and anti histaminics. She was discharged home second day after catheterization.
Discussion: IV iron infusion is often given to iron deficient patient intolerant to oral iron. Patients report number of adverse events from IV iron dextran infusion that can range from injection site reactions to nausea, diarrhea, allergic type reactions including rash, uticaria, dyspnea, hypotension and in most severe cases, shock and death. Severe anaphylactic reaction may be seen in approximately 0.6% of patients. This risk of anaphylactic reactions appears to be probably secondary to dextran that is known to be antigenic. The exact mechanism is not well understood although cross reactivity to antibodies formed in response to polysaccharides generated by gastrointestinal organisms has been offered as an explanation. Although cases of anaphylactic reactions secondary to IV iron have been reported in literature this is the first case to the best of our knowledge in which patient was documented to have MI in absence of CAD. MI was most likely induced by coronary vasospasm and hypotension secondary to anaphylactic reaction. Hence caution must be exercised when adminstering IV iron-dextran infusion. This should only be given when appropriate resuscitative equipment is immediately available. Alternative IV iron preparations should be considered when possible.
New Longer Acting Erythropoiesis Stimulating Proteins (ESPs) Correct Anemia with a Less Frequent Dosing Schedule in a Mouse Model.
Authors: Hartley Cynthia A. , McElroy Patricia , Khaja Raheem , Molineux Graham 
Published: October 2019

Abstract
Introduction: Recombinant human erythropoietin (rHuEPO) has become a standard treatment for the alleviation of anemia resulting from chronic renal failure and chemotherapy induced anemia. Treatment with rHuEPO corrects anemia, resulting in a broad range of clinical benefits including improved quality of life. Darbepoetin alfa (DA), a super-sialylated erythropoietic stimulating protein (ESP) with a 3-fold longer serum half-life than rHuEPO, is approved for use in the treatment of anemia. Another ESP investigated was a hyperglycosylated analog of DA having a greater number of carbohydrate chains and sialic acids (AMG205).
Objective: Our intention was to develop and characterize new ESPs and examine their relative activity and ability to maintain normal hemoglobin levels in a mouse model with stable anemia (hemoglobin 2g/dL below initial levels, > 98 days).
Methods and Results: Clearance of ESPs was reduced and in vivo potency was increased in proportion to number of carbohydrate chains; AMG205 was cleared the slowest and was the most potent of the 3 test molecules. A regimen of repeated low dose exposure to cisplatin (CDDP) was established that resulted in a stable reduction of hemoglobin levels by 2–3 g/dL (12.23±0.75g/dL). The hemoglobin range in control animals not treated with CDDP in this experiment was (14.53±0.57g/dL). Animals made anemic by repeated administration of CDDP were treated with rHuEPO (20μg/kg), DA (10μg/kg) or AMG205 (10μg/kg). Each group consisted of 15 mice. Following the initial injection, hemoglobin was measured every 2–3 days, and subsequent injections were administered when hemoglobin values were < 13 g/dL. Animals were so treated for 98 days. In this manner the number of injections of each ESP required to maintain normal hemoglobin was determined. Mice treated for 98 days required more injections of rHuEPO to maintain normal Hb levels than DA (13 vs.7 injections), while mice treated with AMG205 required 5 injections.
Conclusion: Normal hemoglobin levels were maintained over a 3 month period with repeated administration of the ESPs investigated. The ESPs with increased carbohydrate content had reduced clearance, increased in vivo potency and could maintain hemoglobin within a normal range with fewer injections than rHuEPO.
Folic Acid Supplementation and Twin Pregnancy in Patients with Sickle Cell Disease.
Authors: Ballas Samir K. , Baxter Jason , Riddick Gaye 
Published: October 2019

Abstract
Patients with sickle cell disease (SCD) usually take 1mg of folic acid daily. The rationale for this approach is to maintain effective erythropoiesis with a stable hemoglobin level. Other potential advantages of folate therapy in patients with SCD include the prevention of hyperhomocysteinemia that may predispose to thrombotic events, which, in turn, may lead to painful episodes. Moreover, folate supplementation during pregnancy is known to prevent neural tube defects in infants. The major disadvantage of folate supplementation in patients with SCD is that it may mask vitamin B12 deficiency. Another controversial effect of folic acid supplementation pertains to its potential effect on the number of twins coming to term. We reviewed our database on patients with SCD to determine the effect, if any, of folic acid supplementation on twin pregnancies. The data were collected prospectively since 1981. All patients routinely took 1.0 mg of folic acid orally on a daily basis. Random testing of the level of folic acid in the steady state in women with SCD including those who became pregnant showed increased levels to > 20ng/ml (Normal range: 3.0–18.0 ng/ml) in most patients. Pregnant patients also took additional perinatal vitamins that also contained folic acid. We selected those pregnant patients in whom the outcome of pregnancy was either a liveborn or stillborn at or after 20 weeks’ gestation. We found that 46 patients with SCD became pregnant 60 times between 1981 and 2002 and who met the defined criteria mentioned above. The average maternal age at delivery was 26 years. Fifty-six pregnancies (93%) ended in liveborn and the remaining four (7%) in intrauterine fetal death. Five pregnancies (8.3%) resulted in the delivery of twins. This is a significantly higher rate of multiple births compared to other pregnant women. The reported rate of multiple births is between 0.34 and 1.1% both in Black and Caucasian women respectively. All twin births were dizygotic in nature. Patients with SCD take higher amounts of folic acid on a regular basis for a longer period of time before and after pregnancy than other pregnant women. This may explain why twin pregnancies are higher in these patients. The reason why folate therapy is associated with twinning is unknown at the present. Further studies may clarify the pathogenetic pathway of this phenomenon.
The Role of Reactive Oxygen Species in γ-Globin Gene Activation by Fetal Hemoglobin Inducers.
Authors: Hsiao Cheng-Hui , Li Wei , Lou Tzu-Fang , Lee Edward , Pace Betty S. 
Published: October 2019

Abstract
Enhancing γ-globin expression is an effective therapeutic strategy for sickle cell disease. Fetal hemoglobin (HbF) inducers such as sodium butyrate (NaB), trichostatin A (TSA) and hydroxyurea (HU) have been studied extensively to ascertain molecular and cell signaling mechanisms for γ-gene activation. Reactive oxygen species (ROS) including nitric oxide, superoxide, hydroxyl radicals and hydrogen peroxide stimulate signaling through the cyclic guanosine monophosphate (cGMP) and p38 MAPK pathways. Indirect evidence supports HU as a nitric oxide donor thus providing a mechanism for HbF induction via cGMP activation. Recently, we and others demonstrated a role for p38 signaling in γ-gene induction by HU as well as NaB, TSA and apicidin. However, the ability of HbF inducers to stimulate ROS formation as a mechanism for γ-globin activation via cGMP or p38 MAPK signaling has not been determined. To clarify this mechanism we measured ROS levels using 2′,7′-dichlorofluorescin diacetate which emits fluorescence at a 529 nm wavelength when activated by hydrogen peroxide. We correlated ROS levels with p38 phosphorylation and γ-globin mRNA levels measured by western blot and real-time PCR respectively. Studies were also completed in the absence and presence of myxothiazol, a known inhibitor of ROS formation to confirm our findings. The positive controls menadione and hemin increased ROS levels 4-fold and 3-fold with a concomitant 6.5-fold and 4-fold increase in γ-globin mRNA respectively. Pretreatment with myxothiazol inhibited maximal HbF induction by both agents. By contrast, NaB and TSA did not increase ROS levels in K562 cells therefore they activate γ-globin by a ROS-independent, p38 MAPK-dependent mechanism. We concluded that ROS play a major role in the mechanism for HbF induction by hemin and the vitamin K derivative, menadione. Investigations were completed which confirmed the ability of HU to stimulate ROS formation as well. Studies are underway to determine the role of hydrogen peroxide and/or nitric oxide in HbF induction by HU via cGMP/p38 MAPK cell signaling.
Telomerase Activity and Telomere Length of CD4+CD25+ Regulatory T-Cells under Conditions of In Vitro and In Vivo Expansion.
Authors: Wolf Dominik G.F. , Wolf Anna M. , Koppelstaetter Christian , Rumpold Holger F. , Mayer Gert , Gastl Guenther A. , Gunsilius Eberhard , Tilg Herbert 
Published: October 2019

Abstract
The expandability of CD4+CD25+ regulatory T-cells (Treg) has been shown in vitro and in vivo. Activation of telomerase activity is a prerequisite for clonal expansion and telomere maintenance in T-cells. There is currently no data available on the expression and function of telomerase in proliferating Treg. Analyses of telomere length by flow-FISH, real-time PCR and Southern blotting revealed that Treg isolated from healthy human volunteers have significantly shortened telomeres when compared to CD4+CD25− T-cells. However, telomere length is not further shortened in Treg isolated from the peripheral blood of cancer patients, despite the observation that the regulatory T-cell pool of these patients was significantly enlarged. To gain further insight into maintenance of telomere length of Treg, we induced in vitro proliferation of Treg by stimulation with anti-CD3 and IL-2. This led to a rapid increase of telomerase activity, as determined by PCR-ELISA. However, when we focused on the proliferating fraction of Treg using a sorting strategy based on the dilution of CFSE, we could show a significant telomere shortening in Treg with high proliferative and immmuno-suppressive capacity. Of note, proliferating CFSElow Treg are characterized by high telomerase activity, which however seems to be insufficient to avoid further telomere shortening under conditions of strong in vitro stimulation.
In contrast, under conditions of in vivo expansion of Treg in cancer patients, the induction of telomerase activity is likely to compensate for further telomere erosion. These data might be of importance when considering the application of in vitro expanded Treg for the treatment of GvHD or autoimmune diseases, as telomere shortening might be associated with genomic instability.
Downregulation of TGF-β Signaling by Thrombin in Endothelial Cells.
Authors: Tang Hua , Low Brad , Rutherford Stacey A. , Hao Qin 
Published: October 2019

Abstract
Thrombin activates protease-activated receptor 1 (PAR1) on endothelial cells (ECs) and regulates many aspects of EC biology. A body of evidence has demonstrated that the thrombin-PAR1 pathway is critical for angiogenesis and vascular development. However, the mechanism underlying the proangiogenic effect of thrombin has not been elucidated yet. Here, we report the discovery of a novel functional link between thrombin-PAR1 and transforming growth factor-β (TGF-β) signaling pathways. Using mass spectrometry, confocal immunofluorescence microscopy, cell surface ELISA and a phospho-specific antibody against the serine-phosphorylated endogin, we demonstrated for the first time that thrombin via PAR1 induced the internalization of endoglin and type-II TGF-β receptor (TβRII) but not the type-I receptors in primary human ECs. This effect was mediated by protein kinase C-ζ (PKC-ζ) that was rapidly activated by thrombin in ECs since specific inhibition of PKC-ζ caused aggregation of endoglin and TβRII on cell surface and blocked their internalization in response to thrombin. Furthermore, acute (30 min) and long-term (24 h) pretreatment of ECs with thrombin or PAR1 peptide agonist suppressed the TGF-β-induced serine phosphorylation of Smad2/3, the critical mediators of TGF-β signaling. Moreover, activation of PAR1 led to a profound clustering formation of Smad2/3 and a more spread cytosolic localization, which sequestered Smad2/3 from nucleus and prevented their nuclear translocation evoked by TGF-β. Since TGF-β and its receptors play a crucial role in the resolution phase of angiogenesis, the downregulation of TGF-β signaling by thrombin-PAR1 pathway may provide a new insight into the mechanism of the proangiogenic effect of thrombin.
Long Term Outcome of Patients Undergoing Splenectomy for Immune Thrombocytopenic Purpura.
Authors: Novitzky Nicolas , Seth Yunus , Mothupi Rosalia 
Published: October 2019

Abstract
Splenectomy is very effective in patients with idiopathic thrombocytopenic purpura (ITP) unresponsive to steroids; however it is invasive and has been associated with longstanding immune suppression. We retrospectively reviewed the clinical outcome and laboratory parameters in 52 patients who had undergone splenectomy and had been followed up for a minimum of 5 years. We also studied the long term effectiveness of anti pneumococcal vaccination by testing antibody titres against 5 bacterial antigens. Hospital records of 52 individuals with ITP who required splenectomy were accessed. Of these 52, 47 patients were available for clinical review and consented to provide blood samples to have their laboratory parameters repeated. None of the patients had been treated with prophylactic antibiotics. Except for one, all had received anti pneumococcal vaccination before surgery. The serum anti pneumococcal IgG antibody titres were tested by enzyme linked immunosorbent assay and the results were related to a control group. The complication rate of surgery was 15%, but there was no mortality. Immediately post splenectomy all patients normalised their platelet counts but thrombocytopenia recurred in 6, who required further immunosuppression. Following splenectomy the median time to platelet recovery was 10 days (range 1–90). At 5 years from surgery, 92% remained in response and only 1 / 47 surviving subjects required continuing immunosuppression. In the intervening period subsequent to surgery 5 individuals died. Of these deaths, 4 were unrelated to ITP while 1 patient who had not received anti pneumococcal vaccination, developed rapidly fatal sepsis. At review, patients had significantly higher MCV (p= 0.001), lymphocyte count (p= 0.001) and lower IgM (p= 0.0001). Compared to control samples, of the 5 anti pneumococcal serotypes tested, only the 19F antibody titres were significantly reduced (15.07 ± 17.47 vs. 65.26 ± 79.35 pg/L; p= 0.03) in splenectomised subjects. Splenectomy is highly effective in ITP while the rate of short term complications and long term sequelae appear acceptable. In patients receiving vaccination, anti pneumococcal titres were well maintained and despite no antibiotic prophylaxis no patient in this group developed life threatening infections.
In Normal Controls, a Lower Hb Concentration and Female Sexe Increases Coagulability on the Thrombelastograph (TEG).
Authors: Roeloffzen W.W.F. , Kluin-Nelemans J.C , de Wolf Joost 
Published: October 2019

Abstract
Background. The TEG is used in situations were point of care testing of hemostasis is desired, although its value is still controversially because of insufficient test validation. The main parameters of the TEG are (a) the reaction time (R), the time until the initial fibrin formation and comparable with the coagulation times PT and APTT; (b) clotting time (K), the time until a fixed level of clot firmness is reached; (c) the angle (alpha) is closely related to K and measures the rapidity of fibrin build up and gives information about the clot strength; R, K and alpha are prolonged by anticoagulants and factor deficiencies; (d) maximum amplitude (MA) is a measurement of maximum strength or stiffness of the developed clot; it is especially influenced by platelets and fibrin.
Methods. We performed a multivariate analysis using the Cox multiple-regression model to study the effects of sexe, age, Hb, platelet count, PT, APTT and fibrinogen on the TEG parameters.
Results. Ninety nine normal controls (54 men) age 51 ± 17 years (range 19–87) were studied; no anticoagulants, antithrombotics or oral contraceptives were used. Native whole blood samples were used. The R is significantly influenced by sexe (p<0.001; r=0.4) and APTT (p<0.001; r=0.4); R is in women 19 ± 4, versus 24 ± 5 minutes in men. K is significantly influenced by Hb (p<0.001; r=0.5), fibrinogen (p<0.001; r=−0.4), platelet count (p=0.01; r=−0.3), sexe (p=0.018; r=−0.5) and APTT (p=0.009; r=0.4). The alpha is significantly influenced by the Hb (p<0.001; r=−0.5), fibrinogen (p=0.001; r=0.4), sexe (p=0.008; r=0.5) and APTT (p=0.03; r=−0.4). In normal controls with a Hb of resp.< 8, 8–9 or >=9 mmol/l the K was resp. 6.8 ± 1.7, 8.5 ± 2.5 and 10.5 ± 2.8 minutes; the alpha was resp. 31.4 ± 8.1, 26.1 ± 7 and 21.4 ± 5.8 degrees. The MA was significantly influenced by fibrinogen (p<0.001; r=0.5), age (p<0.001; r=0.5), sexe (p<0.001; r=0.4), platelet count (p=0.02; r=0.2) and PT (p0.03; r=0.1).
Conclusion.. Coagulability measured in the TEG is increased in women compared to men (shortened R and K, larger alpha, increased MA) and coagulability increases with a decrease of the Hb concentration (shortened K and larger alpha).