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Wednesday, August 27, 2008
 Latest
Hematology Medical and Health News Headlines
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Hematology Medical and Health News Headlines
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All Recent Hematology Medical News Headlines |
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Bone marrow sinusoidal endothelial cells undergo nonapoptotic cell death and are replaced by proliferating sinusoidal cells in situ to maintain the vascular niche following lethal irradiation.
Bone marrow sinusoidal endothelial cells undergo nonapoptotic cell death and are replaced by proliferating sinusoidal cells in situ to maintain the vascular niche following lethal irradiation.
Exp Hematol. 2008 Sep;36(9):1143-1156
Authors: Li XM, Hu Z, Jorgenson ML, Wingard JR, Slayton WB
OBJECTIVE: Bone marrow sinusoids remain predominantly host-derived following bone marrow transplantation. Systematic analysis was conducted at the cellular level to investigate how the host sinusoidal structures survived after lethal irradiation. MATERIALS AND METHODS: Apoptosis and cell proliferation assays were performed on bone marrow sections at various time points during the first 2 weeks postirradiation to study the extent of damage to sinusoidal endothelial cells from lethal irradiation and to determine whether cell proliferation contributes to the recovery of the sinusoidal system. RESULTS: Phosphorylated H2AX was present in both hematopoietic and sinusoidal endothelial cells 3 hours after irradiation demonstrating DNA damage. Three days after irradiation, some sinusoidal endothelial cells became terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling -positive, but were caspase-3 and in situ oligo ligation -negative, suggesting nonapoptotic DNA fragmentation. Clusters of sinusoidal endothelial cells that expressed Ki67 appeared 3 days after irradiation, and increased through day 7. These Ki67-positive endothelial cells were host-derived. Bromodeoxyuridine-positive endothelial cells were present in the Ki67-positive areas confirming endothelial cell replication. Twenty percent of the sinusoidal endothelial cells were lost by day 3 after irradiation. The total number of endothelial cells remained relatively unchanged between day 3 and day 14. These results demonstrate that lethal irradiation resulted in limited, nonapoptotic sinusoidal endothelial cell loss, followed by proliferation of preexisting host-derived mature sinusoidal endothelial cells. Our data suggest that DNA repair mechanisms and proliferation of host endothelial cells within the sinusoids are involved in maintenance of the structural integrity of the bone marrow vascular niche following lethal irradiation.
PMID: 18718416 [PubMed - in process] (Source: Experimental Hematology)...
POSTED 08/24/2008 at 06:22 AM --
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Fda approves platelet stimulator as second line therapy for chronic itp
ROCKVILLE, Md. (MedPage Today) -- The FDA has approved romiplostim (Nplate), the first direct platelet stimulator for patients with chronic immune thrombocytopenic purpura (ITP) who are refractory to standard therapy. (Source: MedPage Today Hematology/Oncology)...
POSTED 08/22/2008 at 12:21 PM --
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Clinical features, diagnosis, and management of the antiphospholipid syndrome
Semin Thromb Hemost 2008; 34: 295-304DOI: 10.1055/s-0028-1082275ABSTRACTAlmost 30 years after it was first described as a discrete clinical entity, the antiphospholipid syndrome (APS) remains a challenge for clinicians in a wide range of specialities. There remain ongoing issues regarding nomenclature, the expanding range of clinical manifestations, and management of certain APS patient subgroups. In addition to the presence of appropriate clinical features, the diagnosis of APS also fundamentally requires the finding of positive antiphospholipid antibody test result(s), and unfortunately much still has to be done to improve the robustness, reproducibility, and standardization of these assays. This article discusses ongoing dilemmas and issues related to clinical aspects of APS including (i) the derivation of the current nomenclature and the implications of recent proposals for its revision; (ii) the problems that the protean clinical manifestations pose for many clinicians, in particular those not intimately familiar with APS; (iii) the potential pitfalls of applying the APS classification criteria as diagnostic criteria (although no doubt tempting for nonspecialist clinicians); (iv) the concept of seronegative APS and the effect that recent proposed changes in antiphospholipid antibody testing strategies may have on this diagnosis; and finally (v) an overview of key developments in the clinical management of APS patients over the past 30 years.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Morbidity and mortality in the catastrophic antiphospholipid syndrome: pathophysiology, causes of death, and prognostic factors
Semin Thromb Hemost 2008; 34: 290-294DOI: 10.1055/s-0028-1082274ABSTRACTThe catastrophic variant of the antiphospholipid syndrome (APS) is a condition characterized by multiple vascular occlusive events, usually affecting small vessels and evolving over a short period of time, together with laboratory confirmation of the presence of antiphospholipid antibodies. The pathogenesis of catastrophic APS is not completely understood. The mortality rate was ~50% in the earliest published series, but recently it has clearly fallen by some 20% due to the use, as first-line therapies, of full anticoagulation, corticosteroids, plasma exchanges, and intravenous immunoglobulins. Cerebral involvement has been identified as the main cause of death, being present in one third of patients, and consisting mainly of stroke, cerebral hemorrhage and encephalopathy, followed by cardiac involvement and infection. The only identified prognostic factor for a higher mortality rate is the presence of systemic lupus erythematosus.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Antiphospholipid antibodies and antiphospholipid syndrome in patients with malignancies: features, incidence, identification, and treatment
Semin Thromb Hemost 2008; 34: 282-285DOI: 10.1055/s-0028-1082272ABSTRACTThrombotic events associated with antiphospholipid (aPL) antibodies can be the first manifestation of malignancy. The pathologic significance of aPL antibodies in patients with malignancies, however, is still unclear. It remains an unresolved issue as to whether the presence of aPL antibodies may be considered as an “epiphenomenon” of the malignancy itself or whether it contributes directly to the development of thrombosis in these patients.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Pediatric antiphospholipid antibodies and antiphospholipid syndrome
Semin Thromb Hemost 2008; 34: 274-281DOI: 10.1055/s-0028-1082271ABSTRACTAntiphospholipid syndrome (APS) can occur in children, like adults, with the same diverse spectrum of thrombotic sites but predominately with deep vein thrombosis and stroke. In contrast with adults, however, transient nonthrombogenic antiphospholipid (aPL) antibodies are seen more commonly, usually after childhood infections. In those with “true” aPL antibodies, recurrent thrombotic events seem less frequent than in adults, perhaps reflecting the less prothrombotic hemostatic state of childhood.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Lupus and the antiphospholipid syndrome in pregnancy and obstetrics: clinical characteristics, diagnosis, pathogenesis, and treatment
Semin Thromb Hemost 2008; 34: 267-273DOI: 10.1055/s-0028-1082270ABSTRACTThe antiphospholipid syndrome (APS) in pregnancy is associated with repeated miscarriages and fetal loss. Other complications of pregnancy such as preeclampsia and placental insufficiency are also frequently reported during pregnancy in APS. The pathogenesis of pregnancy failures in APS is related to both the thrombophilic effect of antiphospholipid antibodies and also to different mechanisms including a direct effect of antibodies on trophoblast differentiation and invasion. Although optimal pharmacologic treatment is essential to achieve a successful outcome in APS pregnancy, the standard APS pharmacologic treatment alone may not be sufficient. A good obstetric outcome is the result of careful obstetric monitoring, proper delivery timing, and skillful neonatal care. A multidisciplinary team (obstetricians, rheumatologists, and neonatologists) and the progress in neonatal intensive care are as important as drugs in achieving a good obstetric outcome and to reduce the possible consequences of premature delivery.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Antiphospholipid antibodies and the antiphospholipid syndrome: clinical significance and treatment
Semin Thromb Hemost 2008; 34: 256-266DOI: 10.1055/s-0028-1082269ABSTRACTThis article provides a review of the various types of antiphospholipid (aPL) antibodies and antiphospholipid syndromes, their prevalence, presumed origin, relationship to autoimmunity in general, and their role in the body's defenses and apoptosis. New hypotheses such as the role of antibodies to β2 glycoprotein I (β2GPI) and the signaling of toll-like receptors are also discussed, as is the spectrum of clinical manifestations associated with the demonstration of these antibodies, now assumed to be “pathogenic.” A distinction is made between antibodies present in sera of patients with a variety of microangiopathic syndromes (MAPS; e.g., HELLP syndrome, thrombotic thrombocytopenic purpura, and thrombotic microangiopathic syndromes). In these conditions, the antibodies might not be “pathogenic” but, alternatively, generated by small vessel endothelial damage. These conditions are differentially referred to as microangiopathic antiphospholipid–associated syndromes, and they should be differentiated from the microvascular occlusions that are seen in the antiphospholipid syndrome. Current treatments of the antiphospholipid syndrome are briefly reviewed.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Antiphospholipid antibodies and the antiphospholipid syndrome: pathogenic mechanisms
Semin Thromb Hemost 2008; 34: 236-250DOI: 10.1055/s-0028-1082267ABSTRACTAntiphospholipid antibodies (Abs) are associated with thrombosis and are a risk factor for recurrent pregnancy loss and obstetric complications in patients with the antiphospholipid syndrome. It is generally accepted that the major autoantigen for aPL Abs is β glycoprotein I, which mediates the binding of aPL Abs to target cells (i.e., endothelial cells, monocytes, platelets, trophoblasts, etc.) leading to thrombosis and fetal loss.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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The primary, secondary, catastrophic, and seronegative variants of the antiphospholipid syndrome: a personal history long in the making
Semin Thromb Hemost 2008; 34: 227-235DOI: 10.1055/s-0028-1082266ABSTRACTAlthough many of the clinical features accompanying lupus anticoagulant positivity were documented in the early 1960s and many “non–lupus patients” were also published, it was not until the discovery of antibodies to cardiolipin in the 1980s that the existence and true ramifications of a distinct was defined. A syndrome was in fact recognized in 1985 by the author while at the Hammersmith Hospital and comprised 25 patients who conformed to this new subset of disease, which has now overtaken lupus-associated (secondary) antiphospholipid syndromes in frequency. However, publication of this important milestone was in fact prevented, because of the purveying dogma at that time that “these patients were all suffering from ‘lupus,’” which history has since proved to be incorrect. The syndrome was therefore only clearly defined published in 1988. Subsequently, in the following year, a new and more comprehensive multicenter series comprising 70 patients was documented (including the original 25 patients from 1985) as well as two smaller series by other units. The catastrophic variant of the syndrome with distinct triggering factors, clinical features, and a generally poor prognosis was then defined in 1992, with more than 300 patients with this devastating condition now summarized on the University of Barcelona online registry. The existence of a syndrome has also been suggested, but whether this is related to the presence of undetectable antiphospholipid antibodies or perhaps represents a similar type of vasculopathy or endotheliopathy is unclear at the present time. This article documents a personal account of the events that took place in relation to the description of these syndromes.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Primary, secondary, and catastrophic antiphospholipid syndrome: what's in a name?
Semin Thromb Hemost 2008; 34: 219-226DOI: 10.1055/s-0028-1082265ABSTRACTThe association of the lupus anticoagulant with thrombosis and recurrent pregnancy loss was first recognized over a 20-year period between the early 1960s and early 1980s. The introduction of the anticardiolipin test in 1983 and the recognition of its association with clinical features similar to the lupus anticoagulant led to an exponential growth of interest in this disorder. The belief that anticardiolipin antibodies and lupus anticoagulant belonged to the family of antiphospholipid antibodies led to the disorder being named the (APS). Efforts by individual investigators to introduce criteria for classification of APS and to standardize anticardiolipin antibody and lupus anticoagulant tests were started in the mid-1980s to ensure more reliable recognition and treatment of affected patients. Another layer of complexity was introduced with recognition that many anticardiolipin antibody–positive sera also bound the antigen β glycoprotein I. With increasingly sophisticated epidemiologic and prospective studies in the 1990s, more structured and better-documented criteria for APS were introduced in 1999 and modified in 2006. These criteria have been widely adopted. Whereas data supporting subclassification of APS into primary and secondary subgroups remain tenuous, a small percentage of patients do appear subject to clinical features termed the . Introduction of classification criteria for APS has enabled more reliable prospective studies, the promise of better management, and more valid tests for recognition of the disorder.[...]© Thieme Medical PublishersGet connected:Table of contents | Abstract | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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Antiphospholipid antibodies and the antiphospholipid syndrome i: pathogenesis, clinical features, diagnosis, and management
Semin Thromb Hemost 2008; 34: 213-218DOI: 10.1055/s-0028-1082264© Thieme Medical PublishersGet connected:Table of contents | Full text (Source: Seminars in Thrombosis and Hemostasis)...
POSTED 08/22/2008 at 08:27 AM --
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The subcellular sox11 distribution pattern identifies subsets of mantle cell lymphoma: correlation to overall survival
Gene expression analysis demonstrated high expression of the neuronal transcription factor SOX11 in mantle cell lymphoma (MCL). In contrast to follicular lymphoma, small lymphocytic lymphoma and reactive lymphoid tissue, most MCLs tested (48/53 patients) expressed sox11 protein in the nucleus. Therefore nuclear sox11 expression represents a new tumour marker for a subset of MCL. However, 5/53 MCL cases expressed sox11 only in the cytoplasm; these MCL patients had a shorter survival compared to MCL with nuclear sox11 expression. These results suggest sox11 expression as a new diagnostic marker in MCL that could be related to the clinical and biological behaviour of MCL. (Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Peripheral t-cell lymphoma with a follicular growth pattern: derivation from follicular helper t cells and relationship to angioimmunoblastic t-cell lymphoma
(Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Association between wind speed and the occurrence of sickle cell acute painful episodes: results of a case-crossover study
The role of the weather as a trigger of sickle cell acute painful episodes has long been debated. To more accurately describe the role of the weather as a trigger of painful events, we conducted a case-crossover study of the association between local weather conditions and the occurrence of painful episodes. From the Cooperative Study of Sickle Cell Disease, we identified 813 patients with sickle cell anaemia who had 3570 acute painful episodes. We found an association between wind speed and the onset of pain, specifically wind speed during the 24-h period preceding the onset of pain. Analysing wind speed as a categorical trait, showed a 13% increase (95% confidence interval: 3%, 24%) in odds of pain, when comparing the high wind speed to lower wind speed (P = 0·007). In addition, the association between wind speed and painful episodes was found to be stronger among men, particularly those in the warmer climate regions of the United States. These results are in agreement with another study that found an association between wind speed and hospital visits for pain in the United Kingdom, and lends support to physiological and clinical studies that have suggested that skin cooling is associated with sickle vasoocclusion and perhaps pain. (Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Prevalence of familial malignancy in a prospectively screened cohort of patients with lymphoproliferative disorders
Increasing evidence points to a heritable contribution in the development of lymphoma. The goal of this study was to determine the rate of familial lymphoproliferative malignancy among consecutive lymphoma patients presenting to a tertiary care center and to enrol families with multiple affected first-degree relatives on a data and tissue collection study. Beginning in 2004 all new patients presenting to the Dana-Farber Cancer Institute with non-Hodgkin (NHL) or Hodgkin lymphoma (HL) or chronic lymphocytic leukaemia (CLL) were asked to complete a one-page self-administered family history questionnaire. 55·4% of 1948 evaluable patients reported a first-degree relative with a malignancy, with the highest rate among CLL probands. Lymphoid malignancies were particularly common, with 9·4% of all probands reporting a first-degree relative with a related lymphoproliferative disorder (LPD). This frequency was again highest for CLL, at 13·3% of CLL probands, compared to 8·8% of NHL probands and 5·9% of HL probands (P = 0·002). The prevalence of CLL was significantly increased in parents of CLL probands (P < 0·05), and a greater risk of NHL was seen in fathers of NHL probands than in mothers (P = 0·026). We conclude that familial aggregation of LPDs is common among newly diagnosed patients, varies significantly by diagnosis and contributes meaningfully to the population disease burden. (Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Purification and characterization of sideroblasts from patients with acquired and hereditary sideroblastic anaemia
(Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Secondary non-hodgkin lymphoma (nhl) in children and adolescents after childhood cancer other than nhl
The emergence of non-Hodgkin lymphoma (NHL) during childhood and adolescence as a secondary neoplasm (SN) after previous cancer other than NHL is rare. To describe the characteristics and outcome of NHL following previous cancer other than NHL in children and adolescents, this study analysed the data of patients reported to the NHL-Berlin-Frankfurt-Münster study centre from 1986 to 2005. Out of the total of 2968 NHL-patients registered, 11 patients were assessed as having suffered from NHL as a proven SN. Four additional children had most likely suffered from NHL as an SN, but a late relapse of the first neoplasm could not be ruled out unequivocally. In the patients with proven SN, median age at diagnosis of the primary malignancy was 3·9 years (range 2[ndash]11·7). The median age at diagnosis of NHL was 7·6 years (range 4·7[ndash]18). Only lymphoblastic (n = 7) and diffuse large B-cell (n = 4) lymphomas were diagnosed as SN. The estimated 5-year event-free survival from time of diagnosis of NHL was 91% [95% confidence interval (CI) 74[ndash]100%] in patients with proven SNs and 84% (95% CI 63[ndash]100%) when the patients with probable SNs were included in the analysis. We concluded that secondary NHL in children and adolescents confers a favourable prognosis. (Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Moz/tif2-induced acute myeloid leukaemia in transgenic fish
The inv(8)(p11q13) chromosomal abnormality, described in acute myeloid leukaemias (AML), fuses the histone acetyl-transferase (HAT) MYST3 (MOZ) gene with another HAT gene, NCOA2 (TIF2). We generated a transgenic zebrafish in which the MYST3/NCOA2 fusion gene was expressed under control of the spi1 promoter. An AML developed in 2 of 180 MYST3/NCOA2-EGFP-expressing embryos, 14 and 26 months after injection of the fusion gene in a one-cell embryo, respectively. This leukaemia was characterised by an extensive invasion of kidneys by myeloid blast cells. This model, which is the first zebrafish model of AML, demonstrates the oncogenic potency of MYST3/NCOA2 fusion gene. (Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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Diagnostic performance of serum free light chain measurement in patients suspected of a monoclonal b-cell disorder
The present study aimed to determine the diagnostic performance of different testing strategies to diagnose malignant B-cell disorder or monoclonal gammopathy of unknown significance (MGUS). Sensitivity and specificity were determined in 833 consecutive patients investigated for a monoclonal gammopathy. Serum protein electrophoresis (PE), serum [kappa]/[lambda] free light chain (FLC) ratio, and serum and urine immunofixation electrophoresis (IFE) were performed in all patients. Twenty-eight patients were diagnosed with a malignant plasma cell disorder, 25 with B-cell non-Hodgkin lymphoma and 156 with MGUS. Serum PE (with follow-up IFE) plus FLC had a sensitivity of 82·3% and a specificity of 96·8% and missed one plasmacytoma and 23 patients with MGUS. Serum IFE plus urine IFE had a sensitivity of 92·3% and a specificity of 100% and missed two MGUS patients. Serum IFE plus FLC had a sensitivity of 93·8% and a specificity of 96·8% and missed one MGUS patient. Serum PE plus FLC had a significantly lower sensitivity than serum IFE plus FLC or serum IFE plus urine IFE for the diagnosis of MGUS. The sensitivity of serum IFE plus FLC was comparable to the sensitivity of serum IFE plus urine IFE. The specificity of serum IFE plus FLC, however, was lower than the specificity of serum IFE plus urine IFE. (Source: British Journal of Haematology)...
POSTED 08/21/2008 at 11:00 PM --
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