Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019087 (hemorrhagic diathesis)
 678 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diagnosing Bernard-Soulier syndrome (BSS), a congenital hemorrhagic disorder of blood platelets, is complicated by the difficulty of separating the giant platelets from other blood cells to allow studies of platelet function and structure. We report on the use of three whole blood assays for diagnosing BSS. Whole blood platelet aggregation responses studied with an electrical impedance aggregometer were equivalent to those more laboriously obtained by using platelet-rich plasma prepared by unit gravity sedimentation and studied with an optical light transmittance aggregometer. Platelet aggregation responses were normal with adenosine diphosphate or collagen stimulation but absent with ristocetin or bovine plasma stimulation. Whole blood radioimmunoassay of platelet glycoprotein (GP) expression was performed by using iodinated murine monoclonal antibodies HP1-1D (anti-GP IIb/IIIa) and 6D1 (anti-GP Ib). After incubation with citrated whole blood, centrifugation was used to separate cell-bound antibody that was quantitated with a gamma counter. The patient's whole blood had a normal level of cell-bound GP IIb/IIIa but a substantially reduced level of cell-bound GP Ib (5% of normal mean). Whole blood smear immunocytochemical staining with monoclonal antibodies and qualitative analysis by light microscopy revealed a considerable reduction of GP Ib expression by the patient's giant platelets, whereas GP IIb/IIIa expression was normal. These data helped establish the diagnosis of BSS. We conclude that these three relatively simple assays of platelets in whole blood should be of particular value in the clinical laboratory differential diagnosis of patients with congenital thrombocytopenias and giant platelet syndromes.
 ...
PMID:Bernard-Soulier syndrome: whole blood diagnostic assays of platelets. 272 65

An otherwise healthy woman developed a hemorrhagic diathesis with fluctuating clinical symptoms and laboratory findings, but without thrombocytopenia, over 8 years. In periods of bad clinical condition, a platelet defect, characteristic of thrombasthenia, was found. In contrast to classic thrombasthenia, electrophoresis of the patient's platelet membranes revealed normal amounts of glycoproteins IIb alpha, IIb beta, and IIIa in the normal positions. Monoclonal antibodies, specific for GPIIIa and GPIIb/IIIa, respectively, bound normally to the P1A1-positive platelets from the patient. Although no antibody and no platelet function inhibitor were evident in the autologous plasma, an IgG1 antibody that was bound to the patient's platelets and was directed against GPIIb/IIIa could be demonstrated. After elution from the patient's platelets, this antibody immunoprecipitated GPIIb (both subunits), IIIa, and a 200-kilodalton (kd) band (probably undissociated GPIIb/IIIa complex) from solubilized normal platelets, but did not react with thrombasthenic platelets. Adding the eluate from the patient's platelets to normal platelet-rich plasma immediately caused concentration-dependent inhibition of adenosine diphosphate (ADP)-induced and collagen-induced aggregation and also strong inhibition of ADP-stimulated fibrinogen binding. Because it was very unlikely from the patient's medical history that the antibody was caused by alloimmunization, the hemorrhagic diathesis must be interpreted as acquired thrombasthenia due to an anti-GPIIb/IIIa autoantibody.
 ...
PMID:Acquired thrombasthenia due to GPIIb/IIIa-specific platelet autoantibodies. 301 87

Bleeding time measurement and investigation of platelet aggregation in platelet rich plasma (PRP) are routine procedures for the diagnosis of defects in primary hemostasis. These tests are subject to methodological difficulties and should be well standardized in each individual laboratory. - In the present study, bleeding time was measured using the Simplate II device in 40 normal subjects. Furthermore, platelet aggregation in PRP induced by ADP, collagen, arachidonate, and ristocetin was examined. 26 patients referred for investigation of a suspected mild bleeding disorder, who had a normal plasmatic coagulation profile, a normal von Willebrand factor activity, and a normal platelet count, were similarly studied. - Based on the reference values established in the 40 normal subjects, platelet aggregation was found to be pathologic in 7 patients and normal in 12. In 7 patients platelet aggregation was considered to be borderline-pathologic as defined by the range of platelet aggregability found in the 10% of our normal subjects showing the weakest aggregation responses. Bleeding time was prolonged in only 3 patients whereas it was normal in the remaining 23. There was strong evidence of a hemostatic defect as assessed by systematic patient history in 6 out of 7 patients with pathologic platelet aggregation, but in only 3 out of 19 showing normal or borderline-pathologic aggregation. - Pathologic platelet aggregation, therefore, represents not only an abnormal laboratory finding but is likely to be associated with a hemorrhagic diathesis. Platelet aggregation studies do not permit etiologic diagnosis of the thrombocytopathy except for the well-defined membrane glycoprotein deficiencies. The bleeding time appeared to be of low sensitivity for the diagnosis of mild platelet dysfunction.
 ...
PMID:[Measurement of bleeding time and study of thrombocyte aggregation. Standardization of methods, normal values and results in patients with suspected hemorrhagic diathesis]. 323 91

A 68-year-old male who suffered from thrombocytopenia and mild splenomegaly for 18 years was found to present agranular gray platelets on peripheral blood smear. Bone biopsy revealed a mild, diffuse, reticular fibrosis with no collagen, and electron microscopy of the platelets showed an absence of almost all the alpha-granules. Platelet thrombospondin and fibronectin analysed by SDS-polyacrylamide gel electrophoresis and Rocket immunoelectrophoresis were absent. Follow-up of 4 years showed the same parameters with no evidence of active myeloproliferative or dysmyelopoietic disorders. Hemorrhagic diathesis was limited to ecchymoses and postprostatectomy bleeding, necessitating platelet transfusion. This led us to conclude that our patient probably had a constitutional primary alpha-granule deficiency or gray platelet syndrome. This extremely rare defect has been described in less than 10 patients, all of them very young. Our observation shows that these patients may have a long, uneventful survival.
 ...
PMID:Gray platelet syndrome in the elderly. 341 74

To evaluate the physiologic importance of the different collagen receptors on platelets, we screened 806 patients admitted to the hospital because of hemorrhagic diathesis for eventual laboratory evidence of a pathologic platelet collagen interaction, and found 5 patients with an isolated deficiency in collagen-induced platelet aggregation. Four of these five patients had a partial defect, one had a complete defect. The structural and functional analysis of the platelets from the patient with a complete defect showed a deficiency in glycoprotein (GP) IV and autoantibodies against GPIIb/IIIa, GPIa/IIa, and GPIV. Patient plasma had only a minimal effect on normal control platelets and Naka-negative platelets. The analyses of the defect in the patient and of the data in the literature suggest that a single defect may not result in clinical bleeding (GPIV-deficient patients do not bleed), but may become symptomatic in combination with another defect such as the autoantibodies against GPIa/IIa, GPIV, and/or GPIIb/IIIa, all of which are involved in platelet collagen interactions (three of four of our immune thrombocytopenic purpura patients with anti-GPIV and anti-GPIIb/IIIa autoantibodies had a bleeding disorder). We hypothesize that it is the synergism of two abnormalities that results in the defective function, a mechanism that is in agreement with earlier studies on platelet collagen interaction that suggests that a double defect in platelet collagen interactions is required to become clinically apparent.
 ...
PMID:Autoantibodies against the platelet glycoproteins (GP) IIb/IIIa, Ia/IIa, and IV and partial deficiency in GPIV in a patient with a bleeding disorder and a defective platelet collagen interaction. 768 96

A severe hereditary hemorrhagic diathesis in Simmental cattle has been identified in North America. Platelet numbers and coagulation profiles of affected cattle are normal. We have further characterized the severe dysfunction of platelet aggregation. All agonists tested elicited normal shape change. Aggregations in response to ADP, A23187, and collagen were absent. Aggregations were decreased or required more time for completion in response to PAF and thrombin. No ultrastructural abnormalities were observed in transmission electron micrographs. Dense granule release of ATP in response to PAF was normal. Thrombin-induced aggregation was dependent upon external calcium concentration in normal but not affected animals. Clot retraction in the blood from affected animals was abnormal. The data implicate a defect of Ca++ mobilization or utilization.
 ...
PMID:A primary platelet disorder of consanguineous simmental cattle. 830 52

A 47-year-old woman was admitted to our hospital complaining of subcutaneous hemorrhages. She had taken medicine because of a common cold one month before admission, and two weeks after that, she noticed the hemorrhagic diathesis. Laboratory data on admission were as follows; 1,000/microliters of platelet count (PLT), normal myelogram, normal coagulation tests, positive PAIgG and anti-platelet antibody. She was diagnosed as idiopathic thrombocytopenic purpura and a standard dose of prednisolone was started immediately. However, on the 3rd hospital day (HD), frequent hematemesis from submucosal hematomas developed. Pulse therapy of methylprednisolone and immunoglobulin therapy were ineffective. From the 15th HD slow drip infusion of vincristine and continuous drip infusion of 1, 500 mg/day of gabexate mesilate (GM) were started. Because PLT increased to 85,000/microliters and hematemesis disappeared on the 22nd HD, GM was discontinued. However on the 25th HD, PLT decreased to 1,000/microliters again. After re-starting GM, PLT was maintained at over 100,000/microliters. Subsequent examinations ruled out collagen diseases but revealed that she had Hashimoto's thyroiditis. We concluded that the complement inhibitory action of gabexate mesilate might have contributed to PLT increase in this case, as has been previously reported in three other cases.
 ...
PMID:[Gabexate mesilate induced recovery from thrombocytopenia in a patient with acute ITP]. 877 83

The May-Hegglin anomaly is an extremely rare, autosomal dominant inherited disorder characterized by alterations in white cells and in blood platelets. The granulocytes show basophilic inclusion bodies of no clinical importance. Usually moderate thrombocytopenia with variable platelet size, including giant platelets, is also found. Clinically a mild hemorrhagic diathesis may occur. We report on a so far asymptomatic patient from the second family described by Hegglin et al. in 1964 [1] who had to be treated for repeated life-threatening bleedings. A moderate prolongation of bleeding time was found, corresponding to the reduced platelet count; platelet aggregation induced by ADP, collagen, ristocetin or arachidonic acid was not impaired. Therefore, there is at present no evidence of a congenital platelet function defect in the May-Hegglin anomaly. The bleeding time improved temporarily in our patient on administration of DDAVP (Minirin); platelet substitution is indicated in special situations only.
 ...
PMID:[May-Hegglin anomaly: further studies on thrombocyte dysfunction]. 931 36

Endothelium growth suppressing and tumor-regressing activities were copurified from the conditioned medium of P388D1 culture in the presence of 100 microg/ml carboxymethylated curdlan by a procedure including ammonium sulfate fractionation and six column chromatographies of Ceramic hydroxyapatite, Q-Sepharose, Sephacryl S-300 HR, Matrex PBA-30, PBE94, and anti-bovine serum albumin (anti-BSA) agarose. The intravenous administration of the purified growth suppressing factor for endothelial cells to sarcoma 180-bearing mouse caused a rapid decrease in the number of viable tumor cells in tumor lumps within 16 h. Immunohistochemical study showed that the intravenous injection of the purified factor to sarcoma 180-bearing mouse resulted in hemorrhagic disorder all over the tissue in the tumor lamp. Thus, the purified factor exhibited not only growth suppressing activity for endothelial cells but also tumor regressing activity at a concentration as low as about 15 ng/mouse. The purified factor significantly inhibited in vitro tubulogenesis of bovine artery, human umbilical vein, and adult human darmal microvascular endothelial cells on collagen gel at a concentration of about 5 ng/ml. After the tube formation of endothelial cells was completed on a collagen gel, the purified factor disrupted the tubes at a concentration of about 5 ng/ml within 48 h. These findings demonstrate that endothelium growth suppressing factor is a potent inhibitor of angiogenesis as well as the growth of endothelial cells, and may bring about the regression of a solid tumor by inhibiting angiogenesis.
 ...
PMID:Growth suppressing factor for endothelial cells exhibits tumor regressing activity. 1032 53

The assembly of the tenase complex on the surface of the platelet is an essential step in maintaining normal hemostasis as evidenced by the serious hemorrhagic diathesis associated with either factor IX (FIX) or factor VIII deficiencies. Understanding the regions and or residues of FIX crucial for proper binding to platelets has important clinical implications. The ability of FIX to bind activated platelets in the presence of 4 mmol/l CaCl2 was examined using electrophoretic light-scattering experiments. Wild-type FIX binds to activated platelets with dissociation constant Kd = 7.9 nmol/l. Activated FIX binds to activated platelets with Kd = 2 nmol/l. Activated factor VII does not bind activated platelets at physiological concentrations. The Gla domain of FIX is important for the binding of FIX to activated platelets since a chimera with a factor VII (FVII) template and FIX Gla [FVII(FIXGla)] has Kd = 9.6 nmol/l, and a chimera with a FVII template and FIX Gla, A and the first epidermal growth factor domain (EGF1) [FVII(FIXGla,A,EGF1)] has Kd = 9.7 nmol/l, but a chimera with a FIX template and a FVII Gla [FIX(FVIIGla)] does not bind activated platelets. Altering the fifth residue of FIX from a lysine to an alanine (Lys5<--Ala) abolishes the mutant from binding to collagen but does not affect FIX binding to the activated platelet (Kd = 9.8 nmol/l). Point mutations involved with residues 4 and 5 (Gly4<--Phe and Lys5<--no residue), residue 9 (Phe9<--Ala), residue 10 (Val10<--Lys) and residues 9-11 (Phe9<--Met, Val10<--Lys, Glu11<--Lys) do not bind to activated platelets.
 ...
PMID:Location of the platelet binding site in zymogen coagulation factor IX. 1146 6


<< Previous 1 2 3 Next >>