Once only a subject for science fiction novels, plans for establishing habitation on space stations, the Moon, and distant planets now appear among the short-term goals of space agencies. This article reviews studies that present biomedical issues that appear to challenge humankind for long-term spaceflights. With particularly focus on cells of bone marrow origin, studies involving changes in bone, immune, and red blood cell populations and their functions due to extended weightlessness were reviewed. Furthermore, effects of mechanical disuse on primitive stem cells that reside in the bone marrow were also included in this review. Novel biomedical solutions using space biotechnology will be required in order to achieve the goal of space exploration without compromising the functions of bone marrow, as spaceflight appears to disrupt homeostasis for all given cell types.

OBJECTIVE: The MPL gene encodes the thrombopoietin receptor. Recently MPL mutations (MPL W515L or MPL W515K) were described in patients with essential thrombocythemia (ET) and primary (idiopathic) myelofibrosis (PMF). The prevalence and the clinical importance of these mutations are not clear. In the present study, we aimed to investigate the frequency and clinical significance of MPL W515L/K mutations in our patients with ET and PMF.
METHODS: A total of 77 patients (66 were diagnosed with ET and 11 with PMF) and 42 healthy controls were included in the study. Using peripheral blood samples, the presence of MPL W515L/K mutations and JAK-2 V617F mutation were analyzed by real-time polymerase chain reaction.
RESULTS: In our study, MPL W515L/K or JAK-2 V617F mutations were not observed in healthy controls. JAK-2 V617F mutation was present in 35 patients, of whom 29 had ET (43.9%, 29/66) and 6 had PMF (54.5%, 6/11). In the patient group, MPL W515L/K mutations were found in only 2 PMF cases, and these cases were negative for JAK-2 V617F mutation. The prevalence of MPL W515L/K mutations in the patient group was 2.6%, and the prevalence of MPL W515L/K mutations among the cases negative for the JAK-2 V617F mutation was found to be 4.8%. The 2 cases with MPL W515L/K mutations had long follow-up times (124 months and 71 months, respectively), had no thrombotic or hemorrhagic complications, and had no additional cytogenetic anomalies.
CONCLUSION: MPL W515L/K mutations may be helpful for identifying clonal disease in MPN patients with no established Ph chromosome or JAK-2 V617F mutation.

OBJECTIVE: Myeloproliferative neoplasms (MPNs) like essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF) are acquired clonal hematopoietic stem cell disorders and originate from a multipotent hematopoietic stem cell. The SOCS1 and SOCS3 genes are negative regulators of the JAK/STAT signal pathway. In this study we investigate the promoter methylation of these genes in the pathogenesis of MPNs and secondary erythrocytosis/thrombocythemia.
METHODS: Promoter methylation of SOCS1 and SOCS3 genes was analyzed with methylation-specific PCR. PCR products were analyzed by agarose gel electrophoresis.
RESULTS: No disease-specific CpG island methylation of SOCS1 was observed. Hypermethylation of the SOCS3 promoter was identified in 5 out of 19 (26.3%) PV cases, 2 out of 21 (9.5%) ET cases, 1 out of 5 (20%) PMF cases, and 9 out of 42 (21.4%) cases of secondary erythrocytosis/thrombocythemia.
CONCLUSION: The results revealed that promoter methylation of the SOCS3 gene suggests a possible role for SOCS3 methylation in the pathogenesis of MPNs and secondary erythrocytosis/thrombocythemia.

Objective: To assess the hemostatic efficacy of a new local hemostatic agent, Ankaferd Blood Stopper (ABS), for the control of bleeding following tooth extraction in hemophiliacs.
Materials and Methods: Simple tooth extractions were performed in 27 hemophilia A patients. In the treatment group (n=17) local hemostasis was achieved via application of ABS to the extraction sockets, whereas in the control group (n=10) local hemostasis was achieved via direct packing with gauze.
Results: In all, 57 (21 primary and 36 permanent) teeth extractions were performed in 27 hemophilia A patients. There were no significant differences in age or factor VIII level distribution between the 2 groups (p>0.05). The most significant clinical difference between the groups was associated with the use of ABS; those in the treatment group had significantly shorter duration of bleeding (p=0.002).
Conclusion: This is the first study to evaluate the efficacy of ABS for the control of bleeding following tooth extraction in hemophiliacs. ABS can be considered an alternative local hemostatic agent for reducing clotting factor concentrates in hemophilia patients.

Objective: To define frequency and risk factors of abnormalities in growth, puberty, thyroid function, and bone and carbohydrate metabolisms in children and adolescents with sickle cell disease (SCD).
Materials and Methods: Endocrine problems including short stature, puberty and thyroid disorders, and carbohydrate and bone metabolisms in 50 Turkish children and adolescents with SCD were evaluated. Relationships among sex, disease type, blood transfusions, exchange and exacerbation frequency, ferritin levels, and endocrine pathologies were investigated.
Results: The mean age of the study group was 13.1±2.9 years. Weights and heights of 12 participants (24%) were below -2 standard deviations and 4 participants (8%) had malnutrition. Mean difference (±standard deviation) between bone and chronological age of patients was -1.73±1.86 years. Fifty percent of patients had at least one endocrine abnormality other than vitamin D deficiency and insufficiency. Hypergonadotropic hypogonadism in 3 patients (6%), hypogonadotropic hypogonadism in 1 female patient (2%), and small testicular volume in respect to age in 3 male patients (8.5%) were seen. Growth hormone deficiency was detected in 1 (2%) female patient, and hypothyroidism was diagnosed in 3 patients (6%; 1 central case, 2 cases of primary hypothyroidism). At vertebral level, 5 patients (11.1%) had osteopenia and 1 patient (2.2%) had osteoporosis, while 5 patients (11.1%) had osteopenia at femur neck level. The most common endocrine abnormality was vitamin D deficiency. 25-Hydroxyvitamin D was deficient in 63.2% and insufficient in 18.4% of patients. Sex, disease type, blood transfusion frequency, exacerbation frequency, and ferritin levels were not related to endocrine pathologies. As the age was increased, standard deviation scores of femur neck bone mineral density was decreased (r =-0.56; p<0.05). Vitamin D was lower in patients whose weights and/or heights were below -2 standard deviations from the mean (p<0.05).
Conclusion: Endocrine organ dysfunctions are commonly detected in children and adolescents with SCD, and vitamin D deficiency is the most commonly encountered endocrine disorder. Regular follow- ups of patients for endocrine complications, starting from early ages of patients, and initiation of appropriate treatments will elongate expectancy and quality of life.

Objective: Antiphospholipid antibodies (APLs) could be associated with an increased risk of vascular pathologies in systemic scleroderma. The aim of our study was to search for APLs in patients affected by systemic scleroderma and to evaluate their involvement in the clinical manifestations of this disease.
Materials and Methods: We conducted a cross-sectional descriptive study, from January 2009 until August 2010, with patients received at the Department of Dermatology (Dakar, Senegal). Blood samples were taken at the hematology laboratory and were analyzed for the presence of APLs.
Results: Forty patients were recruited. Various types of either isolated or associated APLs were found in 23 patients, i.e. 57.5% of the study population. The most frequently encountered antibody was IgG anti-β2 GPI (37.5% of the patients), followed by anticardiolipins (17.5%) and lupus anticoagulants (5%). No statistically significant association of positive antiphospholipid-related tests to any of the scleroderma complications could be demonstrated.
Conclusion: A high proportion of patients showing association of systemic scleroderma and APLs suggests the presence of a morbid correlation between these 2 pathologies. It would be useful to follow a cohort of patients affected by systemic scleroderma in order to monitor vascular complications following confirmation of the presence of antiphospholipid syndrome.

Objective: The aim of this study was to investigate the endothelial protein C receptor (EPCR) gene A3 haplotype and plasma soluble EPCR (sEPCR) levels in Turkish pediatric arterial stroke patients.
Materials and Methods: We analyzed 44 pediatric arterial stroke patients and 75 healthy controls. Following DNA isolation, genotyping of the A3 haplotype was determined via PCR and RFLP. Additionally, fasting sEPCR levels were determined via ELISA.
Results: There wasn’t a significant difference in the sEPCR level between the control and patient groups, although the sEPCR level was higher in the patient group. We didn’t observe a difference in the distribution of the CC and CG/GG genotypes between the control and patient groups.
Conclusion: Further study on sEPCR levels at the onset of pediatric stroke is needed in order to reach a more definitive conclusion.

Objective: von Willebrand disease (vWD) is the most common hereditary bleeding disorder. The purpose of this investigation was to determine the prevalence of vWD among adolescents in İzmir and to assess the sensitivity and specificity of PFA-100 as a screening method in detecting this disease.
Material and Methods: Our study was conducted on adolescents in the city of İzmir between October 2006 and March 2007. A total of approximately 1500 high school students between 14 and 19 years of age were planned to be included in the investigation. Survey forms prepared for assessing hemorrhagic diathesis were completed by 1339 individuals (512 males, 827 females). The necessary laboratory tests were performed after having obtained written informed consent from 40 individuals suspected to have hemorrhagic diathesis.
Results: Based on the von Willebrand factor antigen (vWF: Ag) and ristocetin cofactor activity (vWF: RCo) levels and bleeding symptoms, vWD type-1 was diagnosed in 14 individuals (4 males, 10 females; prevalence: 1.04%). The most common bleeding symptom in these patients was found to be epistaxis (10/14). Screening with PFA-100 revealed prolongation in both cartridges (Col/ADP and Col/Epi) in 3 of the 14 patients. PFA-100 was determined to exhibit 21.4% sensitivity and 100% specificity in the diagnosis of vWD.
Conclusion: The PFA-100 device was found to have high specificity but to have exhibited low sensitivity. Therefore, its utilization as a screening test may be problematic in patients with mild type-1 vWD. Specific tests (vWF: RCo, vWF: Ag) are required for the definite diagnosis of vWD. However, further studies with a large number of patients are needed.

OBJECTIVE: Sticky platelet syndrome (SPS) is a common autosomal dominant inherited platelet disorder. SPS is characterized by platelet hyperreactivity and is associated with arterial and venous thrombosis. The aim of this study was to determine the role of SPS in patients with uninduced venous thrombosis.
METHODS: The study included 28 patients (15 male and 13 female) with uninduced venous thrombosis. SPS was defined according to Mammen’s aggregation method, which is described in detail elsewhere.
RESULTS: According to the defined ranges for platelet hyperreactivity, 3 (50%) patients, 2 (33%), and 1 (17%) (n =6 [21%]) with a confirmed diagnosis were classified as type II, I, and III SPS, respectively. In 1 patient SPS was the only hereditary abnormality noted. The other 5 patients carried other inherited coagulation defects, in addition to SPS.
CONCLUSION: The present findings indicate that the prevalence of SPS was 21% in the patients with uninduced venous thrombosis. We therefore suggest that SPS should be considered in the differential diagnosis of such cases.

Objective: Originally, this blind study was designed to check whether blood smears constitute reliable tools to determine sex. However, when we analyzed our data some interesting findings immerged and in this paper we try to highlight them.
Material and Methods: 74 blood smears (35 women and 39 men) have been performed and then stained. 200 polynuclearneutrophils were examined for nuclear appendages and classified into four groups: neutrophils with form A, B or C appendages and neutrophils without any appendage.The difference (A-C) was calculated for each slide. The “cytologic sex” was defined as a male in case of a negative value and as a female otherwise.
Results: Neutrophils bear the same amount of appendages in both genders (p=0.37). But the number of form A is greater in females (p<0.0001) and form C is much more frequent in males (p<0.0001), that is why, the difference A-C is the best way to differentiate between both sexes.The distribution histogram of A-C in women shows a multimodal histogram contrary to men’s graphwhich is a bell-shaped curve. The menstrual cycle was incriminated in this feature.
Conclusion: Blood smear is a reliable tool to determine gender.

Central nervous system (CNS) involvement of Epstein-Barr virus (EBV)-associated lymphoproliferative disease is a rare and serious complication in children with leukemia. Although rituximab therapy seems to be promising in these cases, persistent hypogammaglobulinemia may appear after treatment due to complete depletion of normal B lymphocytes in the peripheral blood. Here we report isolated CNS involvement of EBV-associated lymphoproliferative disorder in a 4-year-old boy with acute leukemia. The patient was treated with rituximab and interferon alpha; however, persistent hypogammaglobulinemia developed as a complication. Given the rarity of the complication in children receiving these agents, our experience with such a case may be helpful to others.

Hydrops fetalis is a serious condition which indicates poor prognosis for the affected fetus. Although the incidence of isoimmune hydrops fetalis has decreased markedly, nonimmune hydrops fetalis cases have been more frequently reported. Nonimmune-mediated hydrops can be caused by hemoglobinopathies. In this report we present a case of nonimmune hydrops fetalis caused by homozygous α-thalassemia. Because of the high incidence of the disease in our country, α-thalassemia should be investigated in all cases with nonimmune hydrops fetalis.

Primary effusion lymphoma (PEL) is a rare type of non-Hodgkin lymphoma that presents with serosal effusion in body cavities, without obvious tumor masses. Although PEL occurs in immunocompromised patients that are human immunodeficiency virus (HIV) positive, it also occurs in immunocompetent human herpes virus-8 (HHV-8)-positive patients. Herein we present an immunocompetent, HIV-negative, CD-20-negative, HHV-8-positive patient with pleural effusion that was diagnosed as PEL. The CHOP protocol and talc pleurodesis were administered. HHV-8 plays a causative role in PEL and is important for differentiating PEL from other types of lymphoma. As such, in addition to pleurodesis antiviral treatment should be considered for optimal treatment outcome.

Chanarin-Dorfman syndrome (CDS) is a very rare autosomal recessive inherited neutral lipid metabolism disorder associated with congenital ichthyosis and multi-system involvement. Observation of lipid vacuoles in neutrophils (Jordan’s anomaly) in peripheral blood smears in patients with ichthyosiform erythroderma is diagnostic. Herein we present 2 siblings with CDS that were referred to Dokuz Eylul University School of Medicine Department of Pediatrics due to ichthyosis. They had hepatomegaly, cataract, growth retardation, and sensorineural hearing loss. Some lipid vacuoles in neutrophils were noted in peripheral blood smear evaluation. Genetic analysis showed homozygous N209X mutation in both patients. They were put on a low-fat high-carbohydrate diet supplemented with medium-chain fatty acids. During 6 months of follow-up, no improvement was observed in both patients. In conclusion, although CDS is a rare lipid storage disease, it should always be a consideration in patients with congenital ichthyosis, especially those with extracutaneous symptoms or signs. The diagnosis of CDS is made based on a very simple test-peripheral blood smear.

Acquired hemophilia A is a rare, but devastating bleeding disorder caused by spontaneous development of autoantibodies directed against coagulation factor VIII. In 40%-50% of patients it is associated with such conditions as the postpartum period, malignancy, use of medications, and autoimmune diseases; however, its cause is unknown in most cases. Acquired hemophilia A should be suspected in patients that present with a coagulation abnormality, and a negative personal and family history of bleeding. Herein we report 3 patients with acquired hemophilia A that had different underlying pathologies, clinical presentations, and therapeutic responses. Factor VIII inhibitor formation in case 1 occurred 6 months after giving birth; underlying disorders were not identified in cases 2 or 3. The bleeding phenotype in these patients’ ranged from no bleeding tendency with isolated prolongation of APTT (activated partial thromboplastin time) to severe intramuscular hematoma and hemarthrosis necessitating recombinant activated factor VII infusion and blood components transfusion. Variable responses to immunosuppressive treatment were also observed.