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Microvascular Occlusion (microvascular + occlusion)
Selected AbstractsThrombotic thrombocytopenic purpura: Results of the patients with thrombotic microangiopathies across Japan by ADAMTS13 analysis during 1998,2008ISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue n2 2009Y. Fujimura Background, Thrombotic microangiopathies (TMAs) are pathological conditions, characterized by generalized microvascular occlusion by platelet thrombi, thrombocytopenia, and microangiopathic hemolytic anemia. Two typical phenotypes of TMAs are hemolytic-uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Severe deficiency of plasma ADAMTS13 activity (ADAMTS13:AC) is more specific for TTP but not for HUS. Materials & Methods, Since 1998, our laboratory has functioned as a nationwide referral center for TMAs by analyzing ADAMTS13. Of 1564 tested patients from 426 hospitals, 919 were positive for TMAs. Levels of ADAMTS13:AC and the ADAMTS13-neutralizing autoantibodies (ADAMTS13:INH) in these patients were determined by chromogenic act-ELISA and/or by classic von Willebrand factor multimer assay. Results, TMA patients consisted of two groups, those with severe (less than 3% of normal control) and those with non-severe deficiency of ADAMTS13:AC. Additionally, both groups were divided into congenital (n = 65) and acquired (n = 854) TMAs. Of the congenital TMA patients, 41 had ADAMTS13:AC deficiency due to gene mutations, while the remaining 24 had the disease of unknown etiology. The 854 patients with acquired TMAs could be largely grouped into three categories: idiopathic TTP (n = 284), idiopathic HUS (n = 106), and secondary TMAs (n = 464). The secondary TMAs were observed in heterogeneous patient groups and were associated with drugs, connective tissue diseases, malignancies, transplantation, pregnancy, E. coli O157:H7 infection, and other factors. All of the patients with acquired severe ADAMTS13:AC deficiency were positive for ADAMTS13:INH. Conclusion, Although TMAs are highly heterogeneous pathological conditions, one third of TMA patients have severe deficiency of ADAMTS13:AC. Platelet transfusions to such patients are contraindicated. Thus, rapid ADAMTS13:AC assays will be prerequisite in medical facilities where TMA patients are treated. [source] Catastrophic multiple organ ischemia due to an anti-Pr cold agglutinin developing in a patient with mixed cryoglobulinemia after treatment with rituximab,AMERICAN JOURNAL OF HEMATOLOGY, Issue 2 2009Joshua Ruch Cold agglutinin disease occurring with cryoglobulinemia is a rare occurrence. Here, we report a patient with mixed cryoglobulinemia that was treated with rituximab and, after response, developed an anti-Pr cold agglutinin that manifested with hemolysis and microvascular occlusion causing mesenteric ischemia and cerebral infarction. Unlike previous reports of patients with cryoglobulinemia and cold agglutinin disease, our patient did not have a detectable cryoprecipitate when his cold agglutinin manifested. Am. J. Hematol, 2009. © 2008 Wiley-Liss, Inc. [source] Major colorectal surgery in a patient with cold agglutinin diseaseANAESTHESIA, Issue 6 2006S. Young Summary We present the case of a 62-year-old man with severe cold agglutinin disease who underwent major colorectal surgery. Cold agglutinin disease is a condition in which auto-antibodies, usually immunoglobulin M, cause red blood cell agglutination at decreased body temperature. Haemolysis may result. Agglutination results in impaired perfusion, resulting in symptomatic Raynaud's phenomenon and acrocyanosis. Haemolysis can result in anaemia and thrombotic events caused by microvascular occlusion, in addition to haemoglobinuria and renal failure. Peri-operative hypothermia is common in all patients and may be associated with significant morbidity, but is potentially catastrophic in a patient suffering from cold agglutinin disease. [source] Microemboli may link spreading depression, migraine aura, and patent foramen ovaleANNALS OF NEUROLOGY, Issue 2 2010Ala Nozari MD Objective Patent foramen ovale and pulmonary arteriovenous shunts are associated with serious complications such as cerebral emboli, stroke, and migraine with aura. The pathophysiological mechanisms that link these conditions are unknown. We aimed to establish a mechanism linking microembolization to migraine aura in an experimental animal model. Methods We introduced particulate or air microemboli into the carotid circulation in mice to determine whether transient microvascular occlusion, insufficient to cause infarcts, triggered cortical spreading depression (CSD), a propagating slow depolarization that underlies migraine aura. Results Air microemboli reliably triggered CSD without causing infarction. Polystyrene microspheres (10,m) or cholesterol crystals (<70,m) triggered CSD in 16 of 28 mice, with 60% of the mice (40% of those with CSD) showing no infarcts or inflammation on detailed histological analysis of serial brain sections. No evidence of injury was detected on magnetic resonance imaging examination (9.4T; T2 weighted) in 14 of 15 selected animals. The occurrence of CSD appeared to be related to the magnitude and duration of flow reduction, with a triggering mechanism that depended on decreased brain perfusion but not sustained tissue damage. Interpretation In a mouse model, microemboli triggered CSD, often without causing microinfarction. Paradoxical embolization then may link cardiac and extracardiac right-to-left shunts to migraine aura. If translatable to humans, a subset of migraine auras may belong to a spectrum of hypoperfusion disorders along with transient ischemic attacks and silent infarcts. ANN NEUROL 2010;67:221,229 [source] | ||||||||||