1/16. Clinical and physiologic studies of two siblings with prekallikrein (Fletcher factor) deficiency.Two siblings with hereditary Fletcher factor (prekallikrein) deficiency were studied for alterations of fibrinolysis, platelet function, skin inflammatory responses, permeability factor (PF/dil) formation and leukocyte chemotaxis. In vivo stimulation of fibrinolytic activity was normal; the bleeding time and platelet functions (adhesivity, aggregation, release reaction) were also normal. Both immediate (wheal-flare reaction to histamine, bradykinin, prostaglandin E1, physical agents) and delayed sensitivity skin test reactions were within normal limits. Migration of subjects' leukocytes to attractants in skin windows and in Boyden-type chambers was the same as that of control leukocytes. serum complement components were essentially normal. One subject's leukocytes showed normal tissue factor production on stimulation by endotoxin, although prekallikrein deficiency did impair the endotoxin-stimulated generation of serum procoagulant activity. PF/dil caused increased vessel permeability in human skin; in vitro generation of PF/dil required both the Hageman factor and prekallikrein. The Fletcher factor-deficient subjects responded in a normal manner to PF/dil. Based on the Fletcher factor-coagulation assay, the biologic half-disappearance time of prekallikrein (after the transfusion of normal plasma in one of the subjects) was estimated at 35 hours. Therefore, these studies suggest that severe prekallikrein (Fletcher factor) deficiency in man is not associated with any clinically significant impairment in hemostasis, fibrinolysis, inflammatory responses or leukocyte function.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/16. Novel applications of recombinant factor viia for the management of pediatric coagulopathic diseases.Recombinant factor viia (rFVIIa) was envisioned for the treatment of bleeding in hemophilia patients with inhibitors. In response to tissue factor expressed upon vessel wall injury, rFVIIa amplifies the thrombin burst primarily on membrane surfaces, including activated platelets. Because it is functional at a key point in the clotting cascade, rFVIIa shows promise as a therapeutic option for various bleeding situations. The prothrombin time (PT) is often used as a surrogate to monitor rFVIIa therapy. Using laboratory and clinical measures of outcome, the use of rVIIa as a therapeutic option in treating several different pediatric coagulopathic conditions is described.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
3/16. Protein C survival during replacement therapy in homozygous protein c deficiency.Homozygous protein C (PC) deficiency is a rare genetic defect that usually results in fatal thrombotic complications (purpura fulminans and DIC), but it can be successfully managed with oral anticoagulants or PC replacement. The successful use of PC replacement for two individuals is described. The activity and antigen levels of PC in fresh frozen plasma (FFP) and prothrombin complex concentrate (PCC) are also reported. The concentration of PC in FFP is 87 /- 15 units/dl. PC is present in all PCC analyzed; however, a ten-fold difference between the various brands and/or lots is noted. The PC activity and antigen correlates well with no significant levels of APC. Upon infusion of FFP into two homozygous PC-deficient children, the PC levels obtained were less than or equal to 30 units/dl post-infusion and undetectable after 12-18 hr. With infusions of PCC, plasma levels of PC obtained were 100-145 units/dl and less than 10 units/dl after 48 hr. The percent recovery and half-lives of PC from FFP and PCC were 49.8% and 7.8 hr, and 84% and 7.4 hr, respectively. One infant was treated every 48 hr for 2 years without significant purpura fulminans or DIC complications. The levels of the other PC system components did not change during the infusion of the PC-rich material. Based on this information, a specific replacement protocol has been developed using a PC-rich concentrate. However, several problems may arise with the "less pure" PC-rich concentrates: catheter-tip thrombosis, related large vessel thrombosis and blood-transmitted diseases. With a specific PC concentrate, replacement therapy is a viable alternative for the long-term management/treatment of homozygous PC deficiency.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
4/16. Evaluation and management of transient ischemic attack and minor cerebral infarction.After immediate intervention for cerebral infarction or transient ischemic attack (TIA), the primary goal is secondary prevention of future cerebral ischemia and prevention of complications related to the initial ischemic event. The goals of the diagnostic evaluation are to (1) determine potential contributing mechanisms (cardioembolic, large-vessel disease of the extracranial and intracranial vessels, small-vessel disease, coagulation defects, and cryptogenic), (2) identify contributing risk factors (hypertension, hyperlipidemia, tobacco use, diabetes), and (3) complete the evaluation in a cost-effective and safe manner. We provide a sequential approach to the diagnostic evaluation of cerebral infarction or TIA to optimize diagnostic yield of testing, minimize cost and potential harm to the patient, and provide information that will change management. This systematic approach focuses on 6 important questions: (1) Are the symptoms consistent with a cerebral infarction or TIA (versus nonischemic pathology)? (2) Where does the ischemic event localize? (3) What etiologies and mechanisms of cerebral infarction and TIA are possible? (4) What is the prevalence of each potential etiology? (5) What treatments are available for this etiology? (6) What tests and studies are useful to evaluate this etiology?- - - - - - - - - - ranking = 3keywords = vessel (Clic here for more details about this article) |
5/16. High titers of CA-125 may be associated with recurrent ischemic strokes in patients with cancer.In addition to etiologies common in the general population, strokes in cancer patients may be caused by hypercoagulable states, hyperviscosity, cardiogenic embolism, and neoplastic vessel infiltration. Intravascular mucins were reported in patients with recurrent thromboembolism. The authors report four patients with metastatic cancer, brain infarcts, and other thromboembolic disease with markedly elevated levels of the tumor marker CA-125 and explore possible associations between this mucinous protein and strokes.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
6/16. Endoscopic band ligation for treatment of non-variceal upper gastrointestinal bleeding.An endoscopic band ligation method was successful in achieving hemostasis in two patients who had severe coagulopathy and profuse gastrointestinal bleeding from a visible vessel in the stomach. Bleeding was not controlled by multiple epinephrine injections or BICAP electrocoagulation. The technique of band ligation was easy to perform and may provide an alternative treatment for non-variceal upper gastrointestinal bleeding in selected cases.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
7/16. Deficiency of platelet membrane glycoprotein Ia associated with a decreased platelet adhesion to subendothelium: a defect in platelet spreading.A bleeding disorder with absent collagen-induced platelet aggregation and adhesion has been described in a patient whose platelets failed to express surface glycoprotein Ia. We studied the interaction of her platelets with subendothelium in an annular perfusion chamber and the interaction with purified human collagen type iii in a rectangular perfusion system under flow conditions. Platelet adherence was almost completely absent both at low and high shear rates. The few platelets which adhered remained in the contact stage without subsequent spreading and aggregate formation. Addition of a monoclonal antibody, which was directed against the von Willebrand moiety of FVIII-VWF, to the blood, completely abolished platelet adherence at high shear rates and had a partial effect at low shear rates. These data indicate that von willebrand factor plays a role in the initial attachment (contact stage) of platelets to subendothelium. We conclude that the bleeding disorder and excessively prolonged bleeding time in our patient are caused by a new specific defect of the platelet-vessel wall interaction.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
8/16. Generalized venocentric lesions in the virus-associated hemophagocytic syndrome.Clinical and autopsy findings in a 41/2-year-old boy who had been healthy until the onset of virus-associated hemophagocytic syndrome are presented. In addition to findings previously reported in association with the syndrome, widely disseminated perivenular expansile nodules of bland necrosis were seen. These nodules were suggestive of vessel injury, with extravasation of vascular contents and focal destruction of normal elements. The morphologic similarities of these nodules to early lesions of pulmonary veno-occlusive disease are discussed.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
9/16. Acute reversible myocardial infarction after blood transfusion in the aged.Seven elderly cases with reversible electrocardiographic changes simulating acute myocardial infarction in the absence of gross myocardial infarction on postmortem examination were observed following the blood transfusion. The underlying diseases were cancer of gastrointestinal tract or gall bladder in 4, gastric ulcer in 2, and 1 of pseudomembranous enterocolitis. The electrocardiogram revealed the abnormal Q waves with monophasic ST elevation and following coronary T inversion. These findings lasted only for 2 to 7 days and returned to the previous normal tracings. The hematocrit was elevated from 28.9 to 47.7 after the blood transfusion of 800 to 1,800 ml. The disseminated intravascular coagulation was shown in 5 cases. GOT levels were within normal ranges except 1 case. Pathological findings in cases with recent electrocardiographic changes were characterized by the mural thromboses, extending into the myocardium through the Thebesian vein. The focal small necroses of the adjacent myocardium or around the thrombosis of small vessels were also observed. In the later phase the fine interstitial fibrosis took place after the resorption of the thrombi and necrotic foci. From these clinical and pathological findings we proposed a new concept of reversible myocardial infarction induced from the hypercoagulability, disseminated intravascular coagulation, and elevated hematocrit.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
10/16. Arterial occlusion causing large bowel infarction--a reflection of clotting diathesis in SLE.The patient, a 44-year old woman with systemic lupus erythematosus, (SLE), developed infarction of the bowel and spleen after occlusion of the inferior mesenteric and splenic arteries, necessitating colectomy and splenectomy. She had had previous cerebral thromboses and a lower limb deep vein thrombosis. Histological examination of the involved vessels showed the presence of thrombus only with the total absence of any vasculitis. The patient demonstrated antibodies to phospholipid - the "lupus anticoagulant" (LA) and antibodies to cardiolipin in serum, both strongly associated with thromboses.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
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