Protein Kinases in Hematological Disorders.

Cell signaling is an important part of the complex system of molecular communication that governs basic cellular activities and coordinates cell cycle machinery. Pathological alterations in the cellular information processing may be responsible for the diseases such as cancer. Numerous diseases may be treated effectively via the pharmacological management of cellular signaling. Protein kinases (PK) have significantly important roles in the cell signal transduction process. Protein kinases phosphorylate serine, threonine, tyrosine and histidine amino acids in a wide variety of molecular networks. Two main PK groups are distinguished; serine/threonine kinase and tyrosine kinases. MAPK (mitogen-activated protein kinases), ERK, EGFR (epidermal growth factor receptor), src, abl, FAK (focal adesion kinase), and JAK (janus family kinase) are considered as the main PK molecular networks. Protein kinases are closely related to the pathobiology of hematologic neoplastic disorders. For instance; JAKV617F point mutation-causing polycythemia vera and essential thrombocytosis occur at the position 617 in the JH2 domain of the JAK2 gene. The protein kinase inhibitor drugs targeting specific kinase molecules have already been developed and widely used in the field of Clinical Hematology. The existence of a local renin-angiotensin system (RAS) specific to the hematopoietic bone marrow (BM) microenvironment had been proposed two decades ago. Local BM RAS is important in hematopoietic stem cell biology and microenvironment. There are interactions among the local BM RAS and PK. For example, ACE2-ang(1-7)-Mas axis inhibits p38 MAPK/NF-КB signaling pathway. The Local BM RAS may have a role in the effect on PK in this biological spectrum. The aim of this review is to outline the functions of PKs in the pathobiology of hematologic neoplastic disorders.

The comparison of bone marrow kinetics between patients with acute myeloid leukemia and acute promyelocytic leukemia after induction chemotherapy.

Background and Aim: Recently, acute promyelocytic leukemia (APL) has shifted from the most hazardous to the best curable type of acute myeloid leukemia. Anthracyclines, all-trans retinoic acid (ATRA) and arsenic derivatives are the most important developments for the treatment of APL. ATRA promotes the terminal differentiation of malignant promyelocytes to mature neutrophils. We aimed to compare platelet and neutrophil recovery time after induction chemotherapy in patients with acute myeloid leukemia (AML) and APL.Materials and Methods: Two hundred and fifteen patients with AML and APL, who were diagnosed and treated in our tertiary care center between the years of 2001 and 2018 were evaluated.Results: One hundred and eighty one AML patients (84.2%) and 34 (15.8%) APL patients were included in this study. The time between neutrophil nadir after induction chemotherapy and neutrophil recovery was longer in APL patients than in AML patients [30.5 (4-52) vs. 20 (5-58), p < 0.001]. The time between platelet nadir after induction chemotherapy and platelet recovery was longer in APL patients than in AML patients [21.5 (4-42) vs. 17 (4-45), p = 0.02].Conclusion: Neutrophil and platelet recovery times were longer in APL patients than in AML patients in our present study. In 60 days, mortality rate was higher in APL patients than AML patients. Non-relapse mortality (NRM) rate was similar between two groups. There was a significant difference between two groups in terms of NRM causes. Platelet and neutrophil recovery time is very important because infection is the most important cause of NRM.

Effects of Ankaferd Hemostat on Helicobacter pylori strains and antibiotic resistance

Background/aim: Ankaferd hemostat (ABS; Ankaferd blood stopper, Istanbul, Turkey) is a folkloric medicinal plant extract. The aim of this study was to determine the effect of Ankaferd hemostat (ABS) on the fate of Helicobacter pylori strains. The study also aims to determine alterations in the antimicrobial resistance of three different H. pylori strains in response to ABS exposure. Materials and methods: H. pylori Strain 1 was obtained from the culture collection ATCC 43504 and passaged three times for viability. Strain 2 was isolated from a gastric ulcer patient and Strain 3 was isolated from a gastritis patient. 1% of ABS was added to all of the strains and antimicrobial susceptibility was observed on 30 and 60 min after application. Results: The efficacy of ABS solutions in achieving significant logarithmic reduction in foodborne pathogens of H. pylori was observed in this study. This study showed that ABS has antibacterial (Anti-H. pylori) effects. Conclusion: Our present study indicated, for the first time, that ABS could act against H. pylori. ABS is clinically used for the management of GI bleeding due to benign and malignant GI lesions. Thus, the possible anti-H. pylori effect of ABS shall expand the therapeutic spectrum of the drug in GI lesions in relation to H. pylori infection such as peptic ulser disease (PUD) and lymphoid tissue (MALT) lymphomagenesis.

Branch retinal vein occlusion associated with platelet activation

Background/aim: The aim of this study is to study subclinical platelet activation by detecting three important platelet activation parameters of mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) in patients with branch retinal vein occlusion (BRVO) in comparison to those in healthy control subjects. Materials and methods: This prospective study included 43 patients with BRVO (Group 1)and 40 control subjects (Group 2). The levels of MPV, PDW, and PCT were measured in both of the studied groups Results: The mean serum level of MPV value was 7.64 ± 0.64 in Group 1 and 7.39 ± 0.42 in Group 2. Mean serum level of PDW was 15.01 ± 1.56 in Group 1 and 14.43 ± 1.03 in Group 2. Mean serum PCT value was 0.19 ± 0.05 in Group 1 and 0.16 ± 0.04 in Group 2. MPV, PDW, and PCT levels were significantly increased in BRVO patients (P < 0.05). Conclusion: Subclinical platelet activation reflected by MPV, PDW, and PCT may have an impact on the genesis of vessel occlusion in BRVO. The results may be important for the clinical management of patients with BRVO

Increased soluble selectins as a reflection of activated platelets and endothelium in Legg-Calve-Perthes disease.

BACKGROUND AND AIM: Legg-Calve-Perthes disease (LCPD) is still an enigma. Hemostatic abnormalities have been indicated in the pathogenesis. We had previously demonstrated enhanced tissue factor pathway inhibitor response, increased global fibrinolytic capacity, and an increase in thrombomodulin in patients with LCPD compared with healthy individuals. These studies emphasized the role of vascular endothelium in pathogenesis of the LCPD. P-selectin is expressed on activated platelets and endothelial cells, and E-selectin is expressed on activated endothelial cells. The aim of this study was to assess circulating E-selectin and P-selectin levels in LCPD patients, which might reflect an endothelium activation and/or injury. MATERIALS AND METHODS: The study included 85 pediatric patients. Group I consisted of 55 patients with LCPD and group II (control) consisted of 30 healthy children. Peripheral venous blood concentrations of E-selectin and P-selectin levels were measured with a commercially available assay. RESULTS: Mean age was 8.41±2.73 years in group I and 8.83±2.92 years in group II. Both E-selectin and P-selectin levels were higher in LCPD patients in comparison with the age-matched controls. E-selectin was 54.92±18.84 pg/mL in group I, 45.54±15.31 pg/mL in group II and P-selectin was 46.40±20.35 pg/mL in group I, 36.92±9.84 pg/mL in group II (P=0.022 and P=0.019, respectively). CONCLUSIONS: On the basis of our results, two important endothelium and platelet markers, E-selectin and P-selectin, are upregulated in LCPD. Our results suggested that activated platelets and possibly endothelial activation, as reflected by enhanced P-selectin/E-selectin kinetics, might contribute to the microvascular thrombosis and/or inflammation of LCPD.

Local Renin-Angiotensin system in normal hematopoietic and multiple myeloma-related progenitor cells.

OBJECTIVE: The prominent functions of the local renin-angiotensin system (RAS) in primitive hematopoiesis further support the hypothesis that local autocrine bone marrow RAS could also be active in neoplastic hematopoiesis. The aim of this study is to examine critical RAS elements in normal CD34+ hematopoietic stem cells and multiple myeloma (MM)-related progenitor cells. MATERIALS AND METHODS: The study group comprised the total bone marrow cells (CBM) of 10 hematologically normal people, the CD34+ stem cell samples (CD34+CBM) of 9 healthy donors for allogeneic peripheral stem cell transplantation, and the CD34+ stem cell samples (CD34+MM) of 9 MM patients undergoing autologous peripheral stem cell transplantation. We searched for the gene expression of the major RAS components in healthy hematopoietic cells and myeloma cells by quantitative real-time polymerase chain reaction analysis. RESULTS: RENIN, angiotensinogen (ANGTS), and angiotensin converting enzyme-I (ACE I) mRNA expression levels of CBM were significantly higher than those in myeloma patients (p=0.03, p=0.002, and p=0.0008, respectively). Moreover, RENIN and ANGTS mRNA expression levels were significantly higher in CD34+ stem cell samples of healthy allogeneic donors compared to those in myeloma patients (p=0.001 and p=0.01). However, ACE I expression levels were similar in CD34+CBM and CD34+MM hematopoietic cells (p=0.89). CONCLUSION: Although found to be lower than in the CBM and CD34+CBM hematopoietic cells, the local RAS components were also expressed in CD34+MM hematopoietic cells. This point should be kept in mind while focusing on the immunobiology of MM and the processing of autologous cells during the formation of transplantation treatment protocols.

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis.

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

Hyper-CVAD regimen in routine management of adult acute lymphoblastic leukemia: a retrospective multicenter study.

Treatment of acute lymphoblastic leukemia is unsatisfactory in adults due to disease and patient-related factors and probably because adult chemotherapy regimens are weaker than pediatric protocols. Worries about inadequacy of adult regimens urged many hematologists, including us, to reconsider their routine treatment practices. In this retrospective multicenter study, we aimed to evaluate results of hyper-CVAD treatment in comparison to other intensive protocols. All patients aged ≤65 years who were commenced on intensive induction chemotherapy between 1999 and 2011 were included in the study. Sixty-eight of 166 patients received hyper-CVAD, 65 were treated with CALGB-8811 regimen and 33 with multiple other protocols. Limited number of patients who were treated with other intensive protocols and mature B-acute lymphoblastic leukemia cases who were mostly given hyper-CVAD were eliminated from the statistical analyses. In spite of a favorable complete remission rate (84.2%), overall (26.3 vs. 44.2% at 5 years, p = 0.05) and disease-free (24.9 vs. 48.2%, p = 0.001) survival rates were inferior with hyper-CVAD compared to CALGB-8811 due to higher cumulative nonrelapse mortality risk (29.7 vs. 5.9%, p = 0.003) and no superiority in cumulative relapse incidence comparison (45% for both arms, p = 0.44). Hyper-CVAD, in its original form, was a less favorable regimen in our practice.

Comparative outcome of reduced intensity and myeloablative conditioning regimen in HLA identical sibling allogeneic hematopoietic stem cell transplantation for acute leukemia patients: a single center experience.

Due to the high transplant related morbidity and mortality (TRM), relatively younger acute leukemia patients that have a good performance status and no comorbidity are eligible for myeloablative conditioning (MAC) followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). The outcomes of 84 consecutive adult patients with ALL (n=38) or AML (n=46) who underwent allo-HSCT from their HLA-identical siblings were evaluated retrospectively. The median age at transplantation was 34 (17-58 years) for the whole patient population. Of these, 24 patients received a MAC and 60 patients received a fludarabine-based reduced intensity conditioning regimen (RIC). After a median follow-up of 32 months (range, 1-119), for the entire group, the 3-year estimated overall survival (OS) was 57.5% and the disease-free survival (DFS) was 51.5%. The OS for ALL and AML patients were 53.9% vs 62.1%: and DFS were 50.5% and 53.4%, respectively. The 3-year estimated OS for RIC and MAC patients were 63.2% and 41.7%; and DFS were 57.1% and 34.7%, respectively. In ALL patients, conditioning regimens (RIC vs MAC) led to similar OS and DFS; however, in AML patients both OS (70.1% vs 21.4%) and DFS (59.3% vs 42.9%) were found to be higher in RIC patients compared to MAC recipients. Overall, the TRM at day 100 was 1.7% and has increased up to 5.1% at 1st year. In multivariate analysis, the diagnosis (p=0.03) and RIC regimen (p=0.027) were the prognostic variables for prolonged OS in all patients; and RIC regimen (p=0.031) was the only prognostic factor for prolonged OS in AML patients. The first complete remission (CR1) was correlated with a prolonged DFS as an independent variable for all patients (p=0.09). Eleven of the RIC patients (18.3%) and 6 of the MAC patients (25%) developed acute graft-versus-host disease (GvHD). Seventeen of the RIC patients (33.3%) and 4 of the MAC patients (16.7%) developed chronic GvHD. In conclusion, RIC conditioning regimens may provide a longer OS and DFS, especially in patients with AML who are in first CR, not eligible for MAC conditioning.

Evaluation of the mean platelet volume in secondary amyloidosis due to familial Mediterranean fever.

Familial Mediterranean fever (FMF) is an inflammatory disorder that is leading cause of secondary amyloidosis (AA). This study was designed to investigate the level of mean platelet volume (MPV) in AA. Seventy-four FMF, 29 AA patients and 180 healthy controls, were included. There was no significant difference between the cases in terms of sex and age. MPV levels were measured in all groups. In the FMF group, MPV level was significantly higher when compared to the control group. MPV level was significantly lower in AA group in comparison with the FMF and healthy control groups. In summary, our present study showed low MPV values in AA due to FMF.

Current management of chronic myeloid leukemia with tyrosine kinase inhibitors.

UNLABELLED: The clinical outcomes and survival of tyrosine kinase inhibitor (TKI)-treated patients with chronic myeloid leukemia (CML) have been significantly improved. The aim of this editorial is to outline critical steps of TKI administration practices during the long-term clinical course of CML based on data obtained from randomized clinical trials and international recommendations. The efficacy of TKI treatment, TKI side effects, off-target complications, and long-term morbidities due to both the disease and the drug are common arguments in the management of CML. Complete hematological response, early complete cytogenetic response, faster major molecular response, and deeper, more durable molecular responses (MR4, MR4.5, MR5) are the ultimate goals for TKI-receiving patients with CML. CONFLICT OF INTEREST: None declared.

Co-expression of t(15;17) and t(8;21) in a Case of Acute Promyelocytic Leukemia: Review of the Literature.

UNLABELLED: Additional chromosomal abnormalities in acute myelogenous leukemia have been identified as one of the most important prognostic factors. Favorable chromosomal changes such as t(8;21), inv(16), and t(15;17) are associated with higher rates of complete remission and event-free survival. Translocation (15;17) characterizes acute promyelocytic leukemia (APL) (French-American-British class M3) in almost all patients. Secondary chromosomal abnormalities are also present in approximately 23%-29% of patients with newly diagnosed APL. The prognostic implications of t(8;21) and other secondary cytogenetic aberrations in APL are reviewed here. We present a 47-year-old woman diagnosed with APL whose initial cytogenetic analysis included both t(8;21) and t(15;17). The initial induction chemotherapy included 3 days of idarubicin (12 mg/m2/day) and daily all-trans retinoic acid (ATRA; 45 mg/m2/day). At the sixth week of treatment, a control bone marrow biopsy was found to be normocellular, t(15;17) bcr3 and t(8;21) were negative, and t(15;17) bcr1 fusion transcripts were reduced from 5007 (1.78525699%) copies per 1 µg RNA to 40 (0.00062020%) with real-time quantitative polymerase chain reaction. Consolidation with 4 days of idarubicin (5 mg/m2/day), ATRA (45 mg/m2/day for 15 days), and cytarabine (1 g/m2/day for 4 days) was then started. However, the patient became pancytopenic and had neutropenic fever after consolidation treatment. Unfortunately, she died 3 months after the time of APL diagnosis, due to acute respiratory distress syndrome-like respiratory problems and multiorgan dysfunction requiring respiratory support and hemodialysis. CONFLICT OF INTEREST: None declared.

Turkish Chronic Myeloid Leukemia Study: Retrospective Sectional Analysis of CML Patients.

OBJECTIVE: here have been tremendous changes in treatment and follow-up of patients with chronic myeloid leukemia (CML) in the last decade. Especially, regular publication and updating of NCCN and ELN guidelines have provided enermous rationale and base for close monitorization of patients with CML. But, it is stil needed to have registry results retrospectively to evaluate daily CML practices. MATERIALS AND METHODS: In this article, we have evaluated 1133 patients' results with CML in terms of demographical features, disease status, response, resistance and use of second-generation TKIs. RESULTS: The response rate has been found relatively high in comparison with previously published articles, and we detected that there was a lack of appropriate and adequate molecular response assessment. CONCLUSION: We concluded that we need to improve registry systems and increase the availability of molecular response assessment to provide high-quality patient care. CONFLICT OF INTEREST: None declared.

Elevated levels of circulating angiotensin converting enzyme in patients with hepatoportal sclerosis.

BACKGROUND AND AIMS: Hepatoportal sclerosis (HPS) is a clinicopathologic condition that is clinically characterized by portal hypertension (varices and portosystemic collateral vessels), splenomegaly and pancytopenia, in the absence of cirrhosis. Although the etiology is obscure, a number of theories such as immunologic and vascular endothelial cellular abnormalities have been put forward to explain the underlying pathophysiology. Angiotensin-converting enzyme (ACE), an important molecule of the renin-angiotensin system (RAS), is also known as a regulatory molecule in systemic and portal circulation in distinct disorders. The aim of the present study was to investigate the possible role of the ACE in the context of RAS in HPS pathogenesis. MATERIALS AND METHODS: The study was conducted on 30 HPS patients (16 men, 14 women; median age 36 years, range 18-63) and 20 healthy controls. The clinical features of HPS patients including demographics, laboratory, and ultrasonography findings were summarized. Serum ACE levels were measured by using commercially available kits. RESULTS: Serum median ACE levels were 36 (8-174) U/l and 16 (8-43) U/l for the HPS patients and controls, respectively. Serum ACE levels were significantly higher in patients with HPS compared to the control group (P < 0.05). CONCLUSION: ACE in the context of RAS may be associated with pathological endothelial occlusive events in the microenvironment of the portal circulation in HPS. Revealing the interactions between circulating and local RAS within the hepatic microenvironment would enlighten the biologic basis and clinical management of liver diseases.

Upper gastrointestinal bleeding in a patient with defective hemostasis successfully treated with ankaferd blood stopper.

Acute gastrointestinal (GI) bleeding is one of the most frequent causes for hospitalization and responsible for a major cause of morbidity and mortality among patients. Ankaferd Blood Stopper (ABS) is a herbal extract attained from five different plants Thymus vulgaris, Glycyrrhiza glabra, Vitis vinifera, Alpinia officinarum and Urtica dioica. Here we report a challenging upper GI bleeding case with a low platelet count and defective hemostasis treated endoscopically with ABS as an adjunctive drug.

A comparison of Jurkat cell-reactive anti-T lymphocyte globulin and fetal anti-thymocyte globulin preparations in the treatment of aplastic anemia.

OBJECTIVE: The aim of this study was to investigate the success rate and effects on survival of different anti-thymocyte globulin (ATG) preparations in patients diagnosed with aplastic anemia. SUBJECTS AND METHODS: Of the total 24 patients included in the study, 12 were male and 12 female with a median age of 44 years (range 16-72). Nine patients received Lymphoglobulin®, 7 Thymoglobulin® and ATG-Fresenius® (ATG-F). There was no significant difference between the three treatment groups in terms of severity of aplastic anemia. RESULTS: The estimated 6-month survival rates for ATG-F, Lymphoglobulin and Thymoglobulin groups were 42.9, 77.8 and 71.4%, respectively. The difference in overall survival rates between groups was not significant, most likely due to the low number of patients. The most striking result was that none of the patients in the ATG-F preparation group showed any response to treatment. The ATG-F group was found to have a significantly inferior response rate (p = 0.07). CONCLUSION: Our data showed that none of the patients responded to ATG-F treatment. Hence, despite the small number of the patients, we recommend that ATG-F should not be used for treatment of severe aplastic anemia.

Ankaferd blood stopper is more effective than adrenaline plus lidocaine and gelatin foam in the treatment of epistaxis in rabbits.

BACKGROUND: Epistaxis is an important emergency that can sometimes be life threatening without effective intervention. Persistent and recurrent bleeding can lead to aspiration, hypotension, hypoxia, or even severe and mortal cardiovascular complications. Providing prompt hemostasis is important, and the hemostatic method used must be easily and locally applicable, efficient, and inexpensive. OBJECTIVE: The aim of this study was to assess the hemostatic efficacy of Ankaferd Blood Stopper (ABS) in an experimental epistaxis model and to determine the histopathologic alterations with topical ABS application. METHODS: Twenty-eight New Zealand rabbits were evaluated in 4 study groups. Topical ABS, gelatin foam (GF), adrenalin + lidocaine (AL), and serum physiologic as negative control (C) were applied to the animals for controlling epistaxis. The bleeding was generated with a standard mucosal incision in all groups. Cotton pieces soaked with ABS, AL, C, and GF were applied to the nasal bleeding area. Time of hemostasis was recorded. Tissue samples were obtained after hemostasis for histopathologic examination. The samples were stained with hematoxylin and eosin (HE) and phosphotungstic acid hematoxylin (PTAH) and were examined under a light microscope. In this experimental study, the observers were blind to ABS, AL, and C but not to GF, because of its solid nature. RESULTS: Median durations required for hemostasis in ABS, AL, GF, and C groups were recorded as 30, 90, 90, and 210 seconds, respectively. The time until termination of bleeding in the ABS group was significantly shorter than that in the AL, GF, and C groups (P = 0.002, P = 0.002, and P = 0.001, respectively). On histopathologic evaluation, after staining with HE, minimal fibrin at the incision edges and a few extravasated erythrocytes were observed in the C, AL, and GF groups. In the ABS group, a dark amorphous material surrounded by fibrin, filling the space between the edges of incisions, was noticed. Fibrin was determined in the C, GF, and AL groups with PTAH stain and in the positive control group. In the ABS group, it was observed that the amorphous substance surrounded by fibrin seen in the HE sections was not stained with PTAH. CONCLUSIONS: Topical nasal ABS application controlled epistaxis faster than C, GF, and AL in this animal bleeding model. The bleeding model used here might fail to replicate the type of injury that would be likely to result in life-threatening bleeding in humans, which should be considered a limitation of the present study. The histopathologic findings in the nasal incision area suggest that ABS might affect global hemostasis by inducing a unique protein network formation, potentially representing a different mechanism of action among conventional antihemorrhagic applications.

Surgical and histopathological effects of topical Ankaferd® hemostat on major arterial vessel injury related to elevated intra-arterial blood pressure.

OBJECTIVE: The aim of this study was to assess the surgical and histopathological hemostatic effects of topical Ankaferd blood stopper (ABS) on major arterial vessel injury related to elevated intra-arterial blood pressure in an experimental rabbit model. METHODS: The study included 14 New Zealand rabbits. ABS was used to treat femoral artery puncture on 1 side in each animal and the other untreated side served as the control. Likewise, for abdominal aortic puncture, only 50% of the aortic injuries received topical liquid ABS and the others did not (control). The experiment was performed under conditions of normal arterial blood pressure and was repeated with a 50% increase in blood pressure. Histopathological analysis was performed in all of the studied animals. RESULTS: Mean bleeding time in the control femoral arteries was 105.0±18.3 s, versus 51.4±9.8 s (p<0.05) in those treated with ABS. Mean blood loss from the punctured control femoral arteries was 5.0±1.5 mg and 1.6±0.4 mg from those treated with ABS (p<0.05). Histopathological examination of the damaged arterial structures showed that ABS induced red blood cell aggregates. CONCLUSION: ABS administered to experimental major arterial vessel injury reduced both bleeding time and blood loss under conditions of normal and elevated intra-arterial blood pressure. ABS-induced erythroid aggregation was prominent at the vascular tissue level. These findings will inform the design of future experimental and clinical studies on the anti-bleeding and vascular repairing effects of the novel hemostatic agent ABS.

Platelet Activation in Ocular Behçet's Patients with Posterior Segment Involvement.

PURPOSE: The aim of the present study was to assess platelet activation by analyzing three platelet activation parameters in ocular Behçet's disease (BD): mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT). METHODS: Twenty-nine patients with active ocular BD (Group 1), 40 patients with inactive ocular BD (Group 2), and 40 healthy adult individuals serving as controls (Group 3) were evaluated. All of the individuals had been performed the complete ophthalmologic evaluation. The levels of MPV, PDW, and PCT were measured in each group. RESULTS: The mean MPV level was 8.40 ± 0.97 in Group 1, 8.32 ± 1.04 in Group 2, and 7.77 ± 0.72 in Group 3. The mean PDW level was 15.12 ± 1.09 in Group 1, 14.97 ± 1.02 in Group 2, and 14.52 ± 0.82 in Group 3. The mean PCT level was 0.23 ± 0.07 in Group 1, 0.21 ± 0.04 in Group 2, and 0.18 ± 0.03 in Group 3. MPV, PDW, and PCT levels were significantly higher in ocular BD patients than controls (P < 0.05). CONCLUSION: Platelet activation may affect vascular occlusion in ocular Behçet's patients with posterior segment involvement. This result may be important in evaluating ocular BD patients.