Sample records for leukostasis
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Leukostasis: Management to Prevent Crisis in Acute Leukemia .
Blackburn, Lisa M; Brown, Shelly; Munyon, Aimee; Orovets, Michelle
2017-12-01
Hyperleukocytosis, a peripheral white blood cell count greater than 100,000/mm3,is most commonly seen in patients with newly diagnosed or relapsed acute lymphoblastic leukemia and acute myeloid leukemia. Leukostasis is a reduction in blood flow related to hyperviscosity. Hyperleukocytosis, causing leukostasis, is an oncologic emergency and requires an exacting assessment and rapid response with appropriate intervention to prevent morbidity and mortality in the first week after diagnosis. The objectives of this article are to equip oncology nurse to identify patients with hyperleukocytosis and to provide nursing interventions that will ensure safe, quality care. A case study is used to demonstrate key concepts that are critical in early assessment, identification, and treatment of patients with leukostasis. . Oncology nurses well versed in the pathophysiology, clinical presentation, and management of leukostasis can make a significant contribution to the safe management of patients with cancer.
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Bruserud, Ø; Liseth, K; Stamnesfet, S; Cacic, D L; Melve, G; Kristoffersen, E; Hervig, T; Reikvam, H
2013-12-01
Hyperleukocytosis is usually defined as leukocyte count >100 × 10(9) L(-1) and can be seen in newly diagnosed leukaemias. Hyperleukocytic leukaemia is associated with a risk of organ failure and early death secondary to leukostasis. Mechanical removal of leukocytes by the apheresis technique, leukocytapheresis, is a therapeutic option in these patients. During a 16-year period, 16 patients were treated with leukocytapheresis (35 apheresis procedures) for hyperleukocytosis/leukostasis. We present our experience, and in addition we review previous studies of hyperleukocytosis/leukocytapheresis in patients with acute myeloid leukaemia (AML). We used a highly standardised approach for leukocytapheresis in leukaemia patients with hyperleukocytosis. The average leukocytapheresis number for each patient was 2·2 (range 1-6). Median leukocyte count before apheresis was 309 × 10(9) L(-1) (range 104-935); the mean leukocyte count reduction was 71%, corresponding to a mean absolute reduction of 219 × 10(9) L(-1). No serious side effects were seen during or immediately after apheresis. The data suggest that our standardised technique for leukocytapheresis effectively reduced the peripheral blood leukaemia cell counts. Previous studies in AML also support the conclusion that this is a safe and effective procedure for the treatment of a potentially life-threatening complication, but apheresis should always be combined with early chemotherapy. © 2013 The Authors. Transfusion Medicine © 2013 British Blood Transfusion Society.
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Savage, Sara R.; McCollum, Gary W.; Yang, Rong
2015-01-01
Purpose The peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) is a transcription factor with roles in metabolism, angiogenesis, and inflammation. It has yet undefined roles in retinal inflammation and diabetic retinopathy (DR). We used RNA-seq to better understand the role of the antagonist and inverse agonist of PPARβ/δ, GSK0660, in TNFα-induced inflammation. Understanding the underlying mechanisms of vascular inflammation could lead to new treatments for DR. Methods RNA was isolated from human retinal microvascular endothelial cells treated with a vehicle, TNFα, or TNFα plus GSK0660. RNA-seq was performed with a 50 bp single read protocol. The differential expression was determined using edgeR and gene ontology, and a pathway analysis was performed using DAVID. RNA-seq validation was performed using qRT-PCR using the primers for ANGPTL4, CCL8, NOV, CXCL10, and PDPK1. Results TNFα differentially regulated 1,830 transcripts, many of which are involved in the cytokine–cytokine receptor interaction, chemokine signaling, and inflammatory response. Additionally, TNFα highly upregulated genes involved in leukocyte recruitment, including CCL5, CX3CL1, and CXCL10. GSK0660 differentially regulated 273 transcripts in TNFα-treated cells compared to TNFα alone. A pathway analysis revealed the enrichment of cytokine–cytokine receptor signaling. In particular, GSK0660 blocks the TNFα-induced upregulation of CCL8, a chemokine involved in leukocyte recruitment. Conclusions TNFα regulates several genes related to retinal leukostasis in retinal endothelial cells. GSK0660 blocks the effect of TNFα on the expressions of cytokines involved in leukocyte recruitment, including CCL8, CCL17, and CXCL10 and it may therefore block TNFα-induced retinal leukostasis. PMID:26015769
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Leukapheresis in acute myeloid leukemia patients with hyperleukocytosis: A single center experience.
Berber, Ilhami; Kuku, Irfan; Erkurt, Mehmet Ali; Kaya, Emin; Bag, Harika Gozukara; Nizam, Ilknur; Koroglu, Mustafa; Ozgul, Mustafa; Bazna, Sezai
2015-10-01
Hyperleukocytosis is defined as WBC count above 100,000/mm(3) in peripheral blood. Increased WBC count leads to leukocyte aggregation, increased blood viscosity, and consequently results in stasis in small blood vessels. Ultimate neurological, pulmonary, gastrointestinal complications, coagulopathy, and tumor lysis syndrome cause increase in morbidity and mortality. Leukapheresis is a treatment modality used for hyperleukocytosis. In patients presenting with hyperleukocytosis the indications for leukapheresis were accepted as having symptoms of leukostasis and prophylactic. Indications for leukapheresis in prophylactic group evaluated according to WBC count. We report a single center experience about leukapheresis in managing 31 AML patients with hyperleukocytosis. In addition to demographic characteristics, disease-related clinical and laboratory findings of the patients were recorded. Survival rates were also calculated. Ten patients were female. The most common of AML subtype was AML-M2. The median number of leukapheresis per patient was 2 and totally 60 leukapheresis cycles were performed in all patients. There was a significant decrease in WBC count and LDH level after leukapheresis as compared with the baseline values (p < 0.05). Early and total mortality were 16.1% and 58.0%, respectively. Alive and died patients were evaluated according to baseline WBC, LDH; increased WBC count and LDH level were found in died patients (p < 0.05). According to leukapheresis indications, patients were divided into two groups: 14 patients in symptomatic leukostasis, 17 patients in prophylaxis. No statistically significant differences were noted between both groups in leukapheresis effectiveness, mean survival time, early and total mortality rate (p > 0.05). None of our patients suffered serious side effects and tumor lysis syndrome during or after apheresis. Leukapheresis is an effective and safe approach to reduce WBC counts in patients with AML with hyperleukocytosis. Further evidence-based data obtained from larger sample sizes are required to better understand the impact of prophylaxis leukapheresis on early and total mortality of AML patients with hyperleukocytosis. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Saliba, Alexandra; Du, Yunpeng; Liu, Haitao; Patel, Shyam; Roberts, Robin; Berkowitz, Bruce A; Kern, Timothy S
2015-01-01
Daily application of far-red light from the onset of diabetes mitigated diabetes-induced abnormalities in retinas of albino rats. Here, we test the hypothesis that photobiomodulation (PBM) is effective in diabetic, pigmented mice, even when delayed until weeks after onset of diabetes. Direct and indirect effects of PBM on the retina also were studied. Diabetes was induced in C57Bl/6J mice using streptozotocin. Some diabetics were exposed to PBM therapy (4 min/day; 670 nm) daily. In one study, mice were diabetic for 4 weeks before initiation of PBM for an additional 10 weeks. Retinal oxidative stress, inflammation, and retinal function were measured. In some mice, heads were covered with a lead shield during PBM to prevent direct illumination of the eye, or animals were treated with an inhibitor of heme oxygenase-1. In a second study, PBM was initiated immediately after onset of diabetes, and administered daily for 2 months. These mice were examined using manganese-enhanced MRI to assess effects of PBM on transretinal calcium channel function in vivo. PBM intervention improved diabetes-induced changes in superoxide generation, leukostasis, expression of ICAM-1, and visual performance. PBM acted in part remotely from the retina because the beneficial effects were achieved even with the head shielded from the light therapy, and because leukocyte-mediated cytotoxicity of retinal endothelial cells was less in diabetics treated with PBM. SnPP+PBM significantly reduced iNOS expression compared to PBM alone, but significantly exacerbated leukostasis. In study 2, PBM largely mitigated diabetes-induced retinal calcium channel dysfunction in all retinal layers. PBM induces retinal protection against abnormalities induced by diabetes in pigmented animals, and even as an intervention. Beneficial effects on the retina likely are mediated by both direct and indirect mechanisms. PBM is a novel non-pharmacologic treatment strategy to inhibit early changes of diabetic retinopathy.
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Bryant, A E; Stevens, D L
1996-01-01
Clostridium perfringens phospholipase C (PLC) and perfringolysin O (PFO) differentially induced human umbilical vein endothelial cell expression and synthesis of endothelial cell-leukocyte adherence molecule-1 (ELAM-1), intracellular leukocyte adherence molecule-1 (ICAM-1), and interleukin-8 (IL-8). PLC strongly induced expression of ELAM-1, ICAM-1, and IL-8, while PFO stimulated early ICAM-1 expression but did not promote ELAM-1 expression or IL-8 synthesis. PLC caused human umbilical vein endothelial cells to assume a fibroblastoid morphology, whereas PFO, in high concentrations or after prolonged low-dose toxin exposure, caused cell death. The toxin-induced expression of proadhesive and activational proteins and direct cytopathic effects may contribute to the leukostasis, vascular compromise, and capillary leak characteristics of C. perfringens gas gangrene. PMID:8557365
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AMA0428, A Potent Rock Inhibitor, Attenuates Early and Late Experimental Diabetic Retinopathy.
Hollanders, Karolien; Hove, Inge Van; Sergeys, Jurgen; Bergen, Tine Van; Lefevere, Evy; Kindt, Nele; Castermans, Karolien; Vandewalle, Evelien; van Pelt, Jos; Moons, Lieve; Stalmans, Ingeborg
2017-02-01
Diabetic retinopathy (DR) is characterized by an early stage of inflammation and vessel leakage, and an advanced vasoproliferative stage. Also, neurodegeneration might play an important role in disease pathogenesis. The aim of this study was to investigate the effect of the Rho kinase (ROCK) inhibitor, AMA0428, on these processes. The response to ROCK inhibition by AMA0428 (1 µg) was studied in vivo using the murine model for streptozotocin (STZ)-induced diabetes, focusing on early non-proliferative DR features and the oxygen-induced retinopathy (OIR) model to investigate proliferative DR. Intravitreal (IVT) administration of AMA0428 was compared with murine anti-VEGF-R2 antibody (DC101, 6.2 µg) and placebo (H 2 O/PEG; 1C8). Outcome was assessed by analyzing leukostasis using fluorescein isothiocyanate coupled concanavalin A (FITC-ConA) and vessel leakage (bovine serum albumin conjugated with fluorescein isothiocyanate; FITC-BSA)/neovascularization and neurodegeneration by immunohistological approaches (hematoxylin and eosin (H&E), terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL), Brn3a). ELISA and Western blotting were employed to unravel the consequences of ROCK inhibition (1 µM AMA0428) on myosin phosphatase target protein (MYPT)-1 phosphorylation, endothelial nitric oxide synthase (eNOS) phosphorylation, and vascular endothelial growth factor (VEGF) levels in retinas of diabetic mice, on NF-κβ activity and ICAM-1 expression in endothelial cells (ECs). In vivo, AMA0428 significantly reduced vessel leakage and neovascularization, respectively, in the STZ and OIR model, comparable to DC101 therapy. Additionally, the ROCK inhibitor decreased neurodegeneration in both models and inhibited leukostasis by 30% (p < 0.05) in the STZ model (p < 0.05), while DC101 had no positive effect on the outcome of these latter processes. ROCK activity was upregulated in the diabetic retina and AMA0428 administration resulted in decreased phospho-MYPT-1, enhanced phospho-eNOS, and reduced VEGF levels. In vitro, AMA0428 interfered with NF-κβ activity, thereby inhibiting ICAM-1 expression in ECs. Targeting ROCK with AMA0428 effectively attenuated outcome in an early DR model (STZ) and a late vasoproliferative retinopathy model (OIR). These findings make AMA0428 a promising candidate with an additional anti-inflammatory and neuroprotective benefit for DR patients, as compared with anti-VEGF treatment.
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Altmann, Christine
2018-01-01
Diabetic retinopathy is a common complication of diabetes mellitus, which appears in one third of all diabetic patients and is a prominent cause of vision loss. First discovered as a microvascular disease, intensive research in the field identified inflammation and neurodegeneration to be part of diabetic retinopathy. Microglia, the resident monocytes of the retina, are activated due to a complex interplay between the different cell types of the retina and diverse pathological pathways. The trigger for developing diabetic retinopathy is diabetes-induced hyperglycemia, accompanied by leukostasis and vascular leakages. Transcriptional changes in activated microglia, mediated via the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) and extracellular signal–regulated kinase (ERK) signaling pathways, results in release of various pro-inflammatory mediators, including cytokines, chemokines, caspases and glutamate. Activated microglia additionally increased proliferation and migration. Among other consequences, these changes in microglia severely affected retinal neurons, causing increased apoptosis and subsequent thinning of the nerve fiber layer, resulting in visual loss. New potential therapeutics need to interfere with these diabetic complications even before changes in the retina are diagnosed, to prevent neuronal apoptosis and blindness in patients. PMID:29301251
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Baqari, Syed Ali Shazif; Haque, Anwarul; Ashraf, Muhammad Shamvil; Alam, Muhammad Matloob; Fadoo, Zehra
2017-07-01
This study was conducted to determine the frequency, clinical profile, and short-term outcome of children with hyperleukocytosis at two pediatric oncology centers in Karachi. Of a total 1,045 patients, 13.97% (n=146) patients had hyperleukocytosis. Majority (61.7%, n=90) were under 10 years of age and 76% (n=146) were male. The symptom duration before diagnosis was more than 30 days in 49.3% (n=72). The median WBC count was 181 x109/L(IQR=130.45298.3) and extreme hyperleukocytosis (>200 x109/L) was observed in 44.5% (n=65) patients. Majority (94.5%, n=138) of patients were diagnosed with acute lymphoblastic leukemia. One or more complications developed in 78% (n=114) of cases. Clinical and laboratory tumor lysis syndrome (TLS) was observed in 17.1% (n=25) and 39% (n=57) patients, respectively. Pulmonary and neurological complications related to leukostasis were noted in 9.5% (n=14) and 27.3% (n=40) of cases, respectively. Infectious complications occurred in 23.2% (n=34) patients. The case-specific mortality was 20.5% (n=30). No mortality was related to early complications of hyperleukocytosis.
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Liu, Xiaochen; Zhang, Bin; McBride, Jeffrey D.; Zhou, Kevin; Lee, Kyungwon; Zhou, Yueping; Liu, Zuguo; Ma, Jian-xing
2013-01-01
Kallistatin is a member of the serine proteinase inhibitor superfamily. Kallistatin levels have been shown to be decreased in the vitreous while increased in the circulation of patients with diabetic retinopathy (DR). Overactivation of the Wnt pathway is known to play pathogenic roles in DR. To investigate the role of kallistatin in DR and in Wnt pathway activation, we generated kallistatin transgenic (kallistatin-TG) mice overexpressing kallistatin in multiple tissues including the retina. In the oxygen-induced retinopathy (OIR) model, kallistatin overexpression attenuated ischemia-induced retinal neovascularization. In diabetic kallistatin-TG mice, kallistatin overexpression ameliorated retinal vascular leakage, leukostasis, and overexpression of vascular endothelial growth factor and intracellular adhesion molecule. Furthermore, kallistatin overexpression also suppressed Wnt pathway activation in the retinas of the OIR and diabetic models. In diabetic Wnt reporter (BAT-gal) mice, kallistatin overexpression suppressed retinal Wnt reporter activity. In cultured retinal cells, kallistatin blocked Wnt pathway activation induced by high glucose and by Wnt ligand. Coprecipitation and ligand-binding assays both showed that kallistatin binds to a Wnt coreceptor LRP6 with high affinity (Kd = 4.5 nmol/L). These observations suggest that kallistatin is an endogenous antagonist of LRP6 and inhibitor of Wnt signaling. The blockade of Wnt signaling may represent a mechanism for its antiangiogenic and antineuroinflammatory effects. PMID:23884893
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Karafin, Matthew S; Sachais, Bruce S; Connelly-Smith, Laura; Field, Joshua J; Linenberger, Michael L; Padmanabhan, Anand
2016-02-01
The National Heart Lung and Blood Institute (NHLBI) hosted a two-day state of the science symposium on therapeutic apheresis in Bethesda, MD on November 28th-29th, 2012. The purpose of the symposium was multifaceted, and included the following aims: (a) To discuss this state of research and key scientific questions in apheresis medicine; (b) To identify gaps in knowledge for relevant cardiovascular diseases, hematological and oncological diseases, infectious diseases and sepsis, renal diseases, and neurological diseases where there may be strong therapeutic rationale for the application of apheresis treatments; (c) To explore ways of coordinating therapeutic apheresis with other medical disciplines and treatment modalities; (d) To identify and prioritize the most important research questions to be answered in apheresis medicine; and (e) To offer NHLBI suggestions on how a structured research approach can be applied to the therapeutic apheresis research agenda in future years. The following document summarizes three such key proposals presented at the meeting for evaluating apheresis therapy for the treatment of pain in sickle cell disease, heparin induced thrombocytopenia, and leukostasis from acute myeloid leukemia. The challenges and limitations regarding apheresis therapy for each disease are discussed, and avenues for future investigation for each disease are outlined. © 2015 Wiley Periodicals, Inc.
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Therapeutic Effects of PPARα Agonists on Diabetic Retinopathy in Type 1 Diabetes Models
Chen, Ying; Hu, Yang; Lin, Mingkai; Jenkins, Alicia J.; Keech, Anthony C.; Mott, Robert; Lyons, Timothy J.; Ma, Jian-xing
2013-01-01
Retinal vascular leakage, inflammation, and neovascularization (NV) are features of diabetic retinopathy (DR). Fenofibrate, a peroxisome proliferator–activated receptor α (PPARα) agonist, has shown robust protective effects against DR in type 2 diabetic patients, but its effects on DR in type 1 diabetes have not been reported. This study evaluated the efficacy of fenofibrate on DR in type 1 diabetes models and determined if the effect is PPARα dependent. Oral administration of fenofibrate significantly ameliorated retinal vascular leakage and leukostasis in streptozotocin-induced diabetic rats and in Akita mice. Favorable effects on DR were also achieved by intravitreal injection of fenofibrate or another specific PPARα agonist. Fenofibrate also ameliorated retinal NV in the oxygen-induced retinopathy (OIR) model and inhibited tube formation and migration in cultured endothelial cells. Fenofibrate also attenuated overexpression of intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and vascular endothelial growth factor (VEGF) and blocked activation of hypoxia-inducible factor-1 and nuclear factor-κB in the retinas of OIR and diabetic models. Fenofibrate’s beneficial effects were blocked by a specific PPARα antagonist. Furthermore, Pparα knockout abolished the fenofibrate-induced downregulation of VEGF and reduction of retinal vascular leakage in DR models. These results demonstrate therapeutic effects of fenofibrate on DR in type 1 diabetes and support the existence of the drug target in ocular tissues and via a PPARα-dependent mechanism. PMID:23043158
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Efficiency of use endobronchial laser doppler-flowmetry in patients with chronic leukemia
NASA Astrophysics Data System (ADS)
Vanina, E. A.; Voitsekhovskiy, V. V.; Landyshev, Y. S.; Tkacheva, S. I.
2016-11-01
In this work indicatorsendobronchial microcirculation were investigated in patients with chronic myeloid leukemia (CML), chronic lymphocytic leukemia (CLL), multiple myeloma (MM), polycythemia vera (PV), idiopathic myelofibrosis (IMF). A diagnostic bronchoscopy was performed using fibreoptic «Olympus» (Japan).Endobronchial laser Doppler flowmetry was carried out on the laser analyzer capillary blood LAK-02 (Russia). Laser Doppler flowmetry indicators such as parameter of microcirculation, the oscillation amplitude in the endothelial, neurogenic, myogenic, cardiac and respiratory ranges were calculated by continuous the Wavelet transforms. Reduced cardiac and respiratory amplitudes in CML and CLL are primarily due to the development leukostasis. If PV is the case, this is due to sludge syndrome. And when MM occurs, it is caused by protein stasis in the vessels of the bronchial tubes. Increased endothelial oscillation amplitudes in the range in CML, PV, IMF and their reduction in MM indicate the presence of endothelial dysfunction in these patients. Increasing the amplitude of oscillations in the range of neurogenic indicates the development of arteriolar vasodilation as a compensatory response to the violation of blood flow. Increasing the amplitude of oscillations of myogenic tone indicating decrease precapillaries as a compensatory reaction to improve blood flow. It is concluded that endobronchial laser Doppler flowmetry is an important method allowing diagnosing the pathology of the microvasculature of the bronchi in chronic leukemia.
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Berber, Ilhami; Erkurt, Mehmet Ali; Kuku, Irfan; Kaya, Emin; Gozukara Bag, Harika; Nizam, Ilknur; Koroglu, Mustafa; Yigit, Ali; Ozgul, Mustafa
2016-02-01
Leukapheresis is an invasive treatment modality used for hyperleukocytosis. Various drugs and fluids are used during the leukapheresis. Aging itself and associated factors such as increased comorbidity, decreased tolerance to drugs, increased drug toxicity give rise to the application of other treatment modalities in elderly patients. Treatment of acute leukemia in the elderly differs from young patients. Consequently, we assumed that outcome, effectiveness, and side effects of leukapheresis treatment used for acute leukemia patients with hyperleukocytosis may be different in elderly compared to younger patients. We retrospectively evaluated a total of 39 patients. Eighteen patients were 65 years and older. Indications for leukapheresis were determined as symptoms of leukostasis and prophylaxis. Acid citrate dextrose-A, calcium gluconate, and plasma were used during the leukapheresis. Age, sex, diagnosis, count, and indications of leukapheresis procedures, leukocyte count, and lactate dehydrogenase level were analyzed at the onset of and after leukapheresis; side effects, causes of death, early and total mortality rates were also analyzed. We compared the two groups with regard to effectiveness, clinical outcomes, and side effects. There were no statistically significant differences between the two groups with respect to sex, diagnosis, initial leukocyte count, lactate dehydrogenase level, number of leukapheresis procedures, rates of side effects, or early and total mortality (P > 0.05). Leukapheresis treatment was effective in both groups (P < 0.05) and no significant difference was found in its effectiveness between two groups (P > 0.05). Leukapheresis is an effective and safe treatment modality in elderly acute leukemia patients with hyperleukocytosis. © 2015 Wiley Periodicals, Inc.
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Malkan, Umit Yavuz; Ozcebe, Osman Ilhami
2017-12-01
Hyperleukocytosis (HL) is defined as the clinical condition when the white blood cell (WBC) count is above 100,000/mm 3 in peripheral blood. It has been already shown in the literature that leukapheresis, a conventional technique to decrease the serum WBC level, is ineffective for long-term survival in cases of hyperleukocytotic acute myeloid leukemia (AML) with leukostasis. However, the effect of leukapheresis on early mortality is still unclear. In this study, we aimed to evaluate the effect of leukapheresis on early mortality of patients with AML who have HL. Twenty-eight de novo patients with AML, diagnosed with HL between 2002 and 2015 at the Hacettepe Hematology Department, were analyzed retrospectively. Leukapheresis was performed in 10 patients, and the mean WBC decrease with leukapheresis was 57.4×10 3 /μl which accounts for 31% of the initial WBC count. The indications for leukapheresis were hyperviscosity and prophylaxis in four and six patients, respectively. In the group of patients who received leukapheresis, three of four patients who had hyperviscosity symptoms died, and three of six patients died who did not have symptoms. In our study, we observed that the leukapheresis procedure is highly effective in reducing plasma WBC levels. However, although it is statistically insignificant, our findings also revealed that there is a much higher rate of death in patients who were treated with leukapheresis. Therefore we conclude that leukapheresis does not lower rates of early death; nevertheless, this finding should be confirmed by prospective studies with larger cohorts. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Portillo, Jose-Andres C; Lopez Corcino, Yalitza; Miao, Yanling; Tang, Jie; Sheibani, Nader; Kern, Timothy S; Dubyak, George R; Subauste, Carlos S
2017-02-01
Müller cells and macrophages/microglia are likely important for the development of diabetic retinopathy; however, the interplay between these cells in this disease is not well understood. An inflammatory process is linked to the onset of experimental diabetic retinopathy. CD40 deficiency impairs this process and prevents diabetic retinopathy. Using mice with CD40 expression restricted to Müller cells, we identified a mechanism by which Müller cells trigger proinflammatory cytokine expression in myeloid cells. During diabetes, mice with CD40 expressed in Müller cells upregulated retinal tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), intracellular adhesion molecule 1 (ICAM-1), and nitric oxide synthase (NOS2), developed leukostasis and capillary degeneration. However, CD40 did not cause TNF-α or IL-1β secretion in Müller cells. TNF-α was not detected in Müller cells from diabetic mice with CD40 + Müller cells. Rather, TNF-α was upregulated in macrophages/microglia. CD40 ligation in Müller cells triggered phospholipase C-dependent ATP release that caused P2X 7 -dependent production of TNF-α and IL-1β by macrophages. P2X 7 -/- mice and mice treated with a P2X 7 inhibitor were protected from diabetes-induced TNF-α, IL-1β, ICAM-1, and NOS2 upregulation. Our studies indicate that CD40 in Müller cells is sufficient to upregulate retinal inflammatory markers and appears to promote experimental diabetic retinopathy and that Müller cells orchestrate inflammatory responses in myeloid cells through a CD40-ATP-P2X 7 pathway. © 2017 by the American Diabetes Association.
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Veenstra, Alexander A; Tang, Jie; Kern, Timothy S
2013-01-01
Leukocytes and proteins that govern leukocyte adhesion to endothelial cells play a causal role in retinal abnormalities characteristic of the early stages of diabetic retinopathy, including diabetes-induced degeneration of retinal capillaries. Leukocyte integrin αmβ2 (CD11b/CD18, MAC1), a protein mediating adhesion, has been shown to mediate damage to endothelial cells by activated leukocytes in vitro. We hypothesized that Neutrophil Inhibitory Factor (NIF), a selective antagonist of integrin αmβ2, would inhibit the diabetes-induced degeneration of retinal capillaries by inhibiting the excessive interaction between leukocytes and retinal endothelial cells in diabetes. Wild type animals and transgenic animals expressing NIF were made diabetic with streptozotocin and assessed for diabetes-induced retinal vascular abnormalities and leukocyte activation. To assess if the leukocyte blocking therapy compromised the immune system, animals were challenged with bacteria. Retinal superoxide production, leukostasis and leukocyte superoxide production were increased in wild type mice diabetic for 10 weeks, as was the ability of leukocytes isolated from diabetic animals to kill retinal endothelial cells in vitro. Retinal capillary degeneration was significantly increased in wild type mice diabetic 40 weeks. In contrast, mice expressing NIF did not develop any of these abnormalities, with the exception that non-diabetic and diabetic mice expressing NIF generated greater amounts of superoxide than did similar mice not expressing NIF. Importantly, NIF did not significantly impair the ability of mice to clear an opportunistic bacterial challenge, suggesting that NIF did not compromise immune surveillance. We conclude that antagonism of CD11b (integrin αmβ2) by NIF is sufficient to inhibit early stages of diabetic retinopathy, while not compromising the basic immune response.
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Veenstra, Alexander A.; Tang, Jie; Kern, Timothy S.
2013-01-01
Leukocytes and proteins that govern leukocyte adhesion to endothelial cells play a causal role in retinal abnormalities characteristic of the early stages of diabetic retinopathy, including diabetes-induced degeneration of retinal capillaries. Leukocyte integrin αmβ2 (CD11b/CD18, MAC1), a protein mediating adhesion, has been shown to mediate damage to endothelial cells by activated leukocytes in vitro. We hypothesized that Neutrophil Inhibitory Factor (NIF), a selective antagonist of integrin αmβ2, would inhibit the diabetes-induced degeneration of retinal capillaries by inhibiting the excessive interaction between leukocytes and retinal endothelial cells in diabetes. Wild type animals and transgenic animals expressing NIF were made diabetic with streptozotocin and assessed for diabetes-induced retinal vascular abnormalities and leukocyte activation. To assess if the leukocyte blocking therapy compromised the immune system, animals were challenged with bacteria. Retinal superoxide production, leukostasis and leukocyte superoxide production were increased in wild type mice diabetic for 10 weeks, as was the ability of leukocytes isolated from diabetic animals to kill retinal endothelial cells in vitro. Retinal capillary degeneration was significantly increased in wild type mice diabetic 40 weeks. In contrast, mice expressing NIF did not develop any of these abnormalities, with the exception that non-diabetic and diabetic mice expressing NIF generated greater amounts of superoxide than did similar mice not expressing NIF. Importantly, NIF did not significantly impair the ability of mice to clear an opportunistic bacterial challenge, suggesting that NIF did not compromise immune surveillance. We conclude that antagonism of CD11b (integrin αmβ2) by NIF is sufficient to inhibit early stages of diabetic retinopathy, while not compromising the basic immune response. PMID:24205223
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Blocking IL-17A Alleviates Diabetic Retinopathy in Rodents.
Qiu, Ao-Wang; Liu, Qing-Huai; Wang, Jun-Ling
2017-01-01
Interleukin (IL)-17A, a proinflammatory cytokine, has been implicated in several autoimmune diseases. However, it is unclear whether IL-17A is involved in diabetic retinopathy (DR), one of the most serious complications of autoimmune diabetes. This study aimed to demonstrate that IL-17A exacerbates DR by affecting retinal Müller cell function. High glucose (HG)-treated rat Müller cell line (rMC-1) was exposed to IL-17A, anti-IL-17A-neutralizing monoclonal antibody (mAb) or/and anti-IL-17 receptor (R)A-neutralizing mAb for 24 h. For in vivo study, DR was induced by intraperitoneal injections of streptozotocin (STZ). DR model mice were treated with anti-IL-17A mAb or anti-IL-17RA mAb in the vitreous cavity. Mice that were prepared for retinal angiography were sacrificed two weeks after intravitreal injection, while the rest were sacrificed two days after intravitreal injection. IL-17A production and IL-17RA expression were increased in both HG-treated rMC-1 and DR retina. HG induced rMC-1 activation and dysfunction, as determined by the increased GFAP, VEGF and glutamate levels as well as the downregulated GS and EAAT1 expression. IL-17A exacerbated the HG-induced rMC-1 functional disorders, whereas either anti-IL-17A mAb or anti-IL-17RA mAb alleviated the HG-induced rMC-1 disorders. Intravitreal injections with anti-IL-17A mAb or anti-IL-17RA mAb in DR model mice reduced Müller cell dysfunction, vascular leukostasis, vascular leakage, tight junction protein downregulation and ganglion cell apoptosis in the retina. IL-17A aggravates DR-like pathology at least partly by impairing retinal Müller cell function. Blocking IL-17A is a potential therapeutic strategy for DR. © 2017 The Author(s)Published by S. Karger AG, Basel.
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Comparison of lung protective ventilation strategies in a rabbit model of acute lung injury.
Rotta, A T; Gunnarsson, B; Fuhrman, B P; Hernan, L J; Steinhorn, D M
2001-11-01
To determine the impact of different protective and nonprotective mechanical ventilation strategies on the degree of pulmonary inflammation, oxidative damage, and hemodynamic stability in a saline lavage model of acute lung injury. A prospective, randomized, controlled, in vivo animal laboratory study. Animal research facility of a health sciences university. Forty-six New Zealand White rabbits. Mature rabbits were instrumented with a tracheostomy and vascular catheters. Lavage-injured rabbits were randomized to receive conventional ventilation with either a) low peak end-expiratory pressure (PEEP; tidal volume of 10 mL/kg, PEEP of 2 cm H2O); b) high PEEP (tidal volume of 10 mL/kg, PEEP of 10 cm H2O); c) low tidal volume with PEEP above Pflex (open lung strategy, tidal volume of 6 mL/kg, PEEP set 2 cm H2O > Pflex); or d) high-frequency oscillatory ventilation. Animals were ventilated for 4 hrs. Lung lavage fluid and tissue samples were obtained immediately after animals were killed. Lung lavage fluid was assayed for measurements of total protein, elastase activity, tumor necrosis factor-alpha, and malondialdehyde. Lung tissue homogenates were assayed for measurements of myeloperoxidase activity and malondialdehyde. The need for inotropic support was recorded. Animals that received a lung protective strategy (open lung or high-frequency oscillatory ventilation) exhibited more favorable oxygenation and lung mechanics compared with the low PEEP and high PEEP groups. Animals ventilated by a lung protective strategy also showed attenuation of inflammation (reduced tracheal fluid protein, tracheal fluid elastase, tracheal fluid tumor necrosis factor-alpha, and pulmonary leukostasis). Animals treated with high-frequency oscillatory ventilation had attenuated oxidative injury to the lung and greater hemodynamic stability compared with the other experimental groups. Both lung protective strategies were associated with improved oxygenation, attenuated inflammation, and decreased lung damage. However, in this small-animal model of acute lung injury, an open lung strategy with deliberate hypercapnia was associated with significant hemodynamic instability.