1/50. Determination of heparin-induced thrombocytopenia: a rapid flow cytometric assay for direct demonstration of antibody-mediated platelet activation.heparin-induced thrombocytopenia (HIT) and thrombosis are serious complications of heparin therapy. Recently, we have reported a practical and rapid functional flow cytometric assay (FCA) for the diagnosis of HIT with high specificity and sensitivity compared with the radioactive serotonin-release assay (SRA). In the present study, we added an immune-neutralization assay to directly demonstrate the antibody-mediated process, and tested the immune compatibility of low-molecular-weight heparin (LMWH) Lovenox and the heparinoid Orgaran (danaproid) using plasma from 18 patients with HIT confirmed by both FCA and SRA. The clinical utility of this modified method is demonstrated by a pediatric patient with a complex clinical presentation who developed thrombocytopenia with multiple thromboses while on heparin therapy. ELISA and SRA (performed in three independent laboratories) for diagnosis of HIT were both negative. In contrast, the FCA for detecting activated platelets expressing anionic phospholipids, was highly and reproducibly positive with both unfractionated and LMWH. Another FCA also demonstrated the surface expression of the alpha-granule membrane p-selectin (CD62p). Compatibility testing with the heparinoid Orgaran was also positive (and with plasma from 4 of the 18 patients with HIT). heparin was discontinued, along with full recovery of the platelet count. The capacity of the patient's plasma to activate platelets in the presence of heparin gradually decreased over 4 weeks consistent with antibody clearance. The responsible mechanism was clarified using an immune-neutralization assay, which showed a dose response neutralization of the plasma activity by antibodies against human immunoglobulin g (IgG) and IgM. This assay was also reproducible in the 18 patients with HIT. We conclude that the functional FCA with its modification is practical, sensitive, and specific for reliable diagnosis of HIT. It can simultaneously assess the compatibility of alternative therapies and directly confirm the antibody-mediated process. Further, it is particularly useful to clarify mechanisms of thrombocytopenia and thrombosis and to direct therapy in patients with a complex presentation and confounding laboratory results who often need prompt diagnosis and treatment.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
2/50. Multiple episodes of thrombosis in a patient with Becker muscular dystrophy with marked expression of utrophin on the muscle cell membrane.We previously reported a patient with Becker muscular dystrophy (BMD) who exhibited a benign clinical phenotype and marked expression of utrophin on the muscle cell membrane. The patient developed multiple episodes of thrombosis (middle cerebral and femoral arteries) in the course of the disease. We re-examined the biopsy muscle specimen from the patient immunohistochemically as to the expression of procoagulant or anticoagulant factors. We found a lower expression of thrombomodulin on the muscle cell membrane in the BMD patient compared with other BMD or Duchenne muscular dystrophy (DMD) patients. Although utrophin up-regulation in muscle is thought to prevent the muscle wasting in dystrophin-deficient DMD or BMD, the data obtained in the present study indicate that up-regulated utrophin may have an unexpected influence on the function of the vascular or coagulation system.- - - - - - - - - - ranking = 6keywords = membrane (Clic here for more details about this article) |
3/50. A case of primary antiphospholipid antibody syndrome with acute renal failure showing thrombotic microangiopathy.An 18-year-old woman complained of fever and edema and was admitted to Showa University Hospital for treatment of thrombocytopenia and deteriorating renal function. Laboratory studies demonstrated the presence of lupus anticoagulant (LA), prolongation of prothrombin time, hemolytic anemia, a negative Coombs' test, the absence of antinuclear antibodies, and a normal fibrinogen level. Renal biopsy revealed mesangial hypercellularity, severe endocapillary cell damage, and double contour of the basement membrane walls. Immunofluorescence studies demonstrated focal, peripheral, and finely granular deposits for IgG, IgM, and IgA but were negative for fibrinogen. Electron microscopy showed glomerular capillary loops with subendothelial widening and subendothelial deposits, mesangiolysis, mesangial interposition, and marked luminal narrowing. biopsy findings were consistent with thrombotic microangiopathy. The patient was treated with hemodialysis, methylprednisolone pulse therapy, and dipyridamole. After treatment, LA disappeared, the prothrombin time became normal, and renal function improved. The renal lesions in this patient were caused by primary antiphospholipid antibody syndrome. This case strongly suggests an important causal relationship between LA and renal lesions in thrombotic microangiopathy. We present this case to promote understanding of the pathogenesis of primary antiphospholipid antibody syndrome. copyright copyright 1999 S. Karger AG, Basel- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
4/50. Disappearance of "pseudocholangiocarcinoma sign" in a patient with portal hypertension due to complete thrombosis of left portal vein and main portal vein web after web dilatation and transjugular intrahepatic portosystemic shunt.The main portal vein web is probably a consequence of portal vein thrombosis, which is a very rare cause of portal hypertension. Principal manifestations are related to the degree of portal hypertension. In the literature, no data has been found for the treatment modality of portal vein web. We report, herein, the clinical and laboratory findings of a 38-year-old woman with angiographically proven incomplete main portal vein web and complete thrombotic occlusion of the left portal vein causing pseudocholangiocarcinoma sign (PCCS) on the common bile duct. She was treated by transjugular intrahepatic portosystemic shunt (TIPS) and membrane dilatation, which resulted in complete disappearance of collaterals and PCCS. It appears that TIPS and balloon dilatation of the portal vein web via transjugular approach was effective in decreasing portal pressure and its consequences.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
5/50. Successful lysis of an obstructive aortic and renal artery thrombus in a neonate on extracorporeal membrane oxygenation.We describe a neonate on venoarterial extracorporeal membrane oxygenation (ECMO) with acute renal failure associated with extensive aortic and bilateral renal artery thrombosis. Concurrent anticoagulation and continuous systemic thrombolytic therapy with tissue plasminogen activator (t-PA) resulted in complete thrombolysis as evaluated by Doppler flow. The relative risk and benefits of thrombolytic therapy in heparinized patients undergoing ECMO needs to be further studied.- - - - - - - - - - ranking = 5keywords = membrane (Clic here for more details about this article) |
6/50. The use of alteplase for the resolution of an intravesical clot in a neonate receiving extracorporeal membrane oxygenation.We present a case of the use of alteplase for the lysis of a large urinary bladder clot. A neonate presented with respiratory failure, secondary to a left diaphragmatic hernia necessitating the need for extracorporeal membrane oxygenation (ECMO) support. On day 3 of ECMO support, hematuria was noted, and a subsequent urinary bladder ultrasound revealed a significant urinary bladder clot. Alteplase (0.5-1 mg) was instilled into the urinary bladder via a 10 French Foley catheter (Sherwood Medical, St. Louis, MO). The catheter was clamped for 1 hour, followed by irrigation with normal saline. Multiple doses of alteplase were administered, resulting in complete resolution of the bladder clot. No adverse effects were attributed to the use of the intravesical alteplase. Alteplase seems to be safe and effective for the resolution of bladder clots, thereby potentially avoiding more invasive surgical procedures.- - - - - - - - - - ranking = 5keywords = membrane (Clic here for more details about this article) |
7/50. Altered erythrocyte endothelial adherence and membrane phospholipid asymmetry in hereditary hydrocytosis.The risk for thrombosis is increased in patients with hereditary hydrocytosis, an uncommon variant of hereditary stomatocytosis. erythrocytes from 2 patients with hydrocytosis were studied to gain insight into the mechanism of thrombosis in this disorder. erythrocytes demonstrated abnormal osmotic scan ektacytometry and decreased erythrocyte filtration rates. There was also a mild increase in adherence of erythrocytes to endothelial monolayers in a micropipette assay. Adhesion of erythrocytes to the subendothelial matrix proteins thrombospondin and laminin, however, was not significantly increased. Percentages of hydrocytosis erythrocytes and reticulocytes with phosphatidylserine exposed on the outer surfaces were increased in both patients compared with healthy controls, indicating altered membrane phospholipid asymmetry. Increased phosphatidylserine exposure accelerating thrombin-forming processes has been proposed as a mechanism for thrombosis in sickle cell disease and beta-thalassemia and may play a similar role in hereditary hydrocytosis.- - - - - - - - - - ranking = 5keywords = membrane (Clic here for more details about this article) |
8/50. Absent end diastolic flow in umbilical artery and umbilical cord thrombosis at term of pregnancy.BACKGROUND: meconium staining of the fetus and placenta is associated with increased neonatal mortality and asphyxia. Very often it is unclear whether the discharge of meconium is a cause or an effect of fetal distress. In the available literature there are no large epidemiological studies of pregnancy outcome with meconium-related lesions, even though this could be useful to improve our state of knowledge on this topic. CASE REPORT: A case of umbilical cord vascular necrosis is described. A severely asphyxiated infant was delivered at 39 weeks' gestation by cesarean section due to alarming results of fetal heart rate monitoring and rupture of membranes with meconium-stained amniotic fluid. There was no meconium aspiration. We report a review of 15 similar cases. In the whole series, a linkage between umbilical cord vascular necrosis and evidence of remote meconium discharge always seems to be detectable. The pathophysiological mechanism is unknown. CONCLUSIONS: It is still not clear why only a tiny percentage of cases with meconium-stained amniotic fluid develops umbilical cord lesions and poor pregnancy outcome. Further investigations are needed to explain why some meconium-stained newborns suffer severe neurological and other damage even without meconium aspiration.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
9/50. tricuspid valve thrombus and pulmonary embolus in an infant with homozygous thermolabile methylenetetrahydrofolate reductase and heterozygous prothrombin G20210A variant.We describe an unusual and interesting case of a full-term infant presenting at 7 days of life with HSV pneumonitis and a tricuspid valve thrombus ultimately requiring extracorporeal membrane oxygenation. The infant subsequently developed a pulmonary embolus. The infant was found to be heterozygous for the prothrombin G20210A mutation and homozygous for the methylenetetrahydrofolate reductase C667T mutation. The patient was treated with low molecular weight heparin for a total of 3 months and has not had a recurrent thrombosis. This case illustrates that a combination of congenital and acquired thrombophilic risk factors can contribute to a significant thrombotic event.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
10/50. Acute popliteal artery occlusion after arthroscopic posterior cruciate ligament reconstruction.Arthroscopic posterior cruciate ligament reconstruction may carry certain risks of complications, including injury to the neurovascular structures in the popliteal region. Acute occlusion of the popliteal artery, a limb-threatening complication, was reported after total knee arthroplasty. We report a case of acute popliteal artery occlusion after arthroscopic posterior cruciate ligament reconstruction. The possible causes included underlying artherosclerosis, the use of pneumatic tourniquet, surgical manipulation, and arterial spasm. early diagnosis and prompt surgical treatment are the keys to success in the treatment of this limb-threatening complication. Spontaneous resolution of the thrombus such as is reported in this case is exceptional.- - - - - - - - - - ranking = 46.069738976158keywords = ligament (Clic here for more details about this article) |
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