Готові списки джерел за темами / Gray platelet syndrome

Добірка наукової літератури з теми "Gray platelet syndrome"

Автор: Grafiati
Опубліковано: 22 червня 2024

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Зміст

  1. Статті в журналах
  2. Дисертації
  3. Частини книг
  4. Тези доповідей конференцій

Статті в журналах з теми "Gray platelet syndrome":

1

Wills, E. J. "Gray Platelet Syndrome." Ultrastructural Pathology 13, no. 4 (January 1989): 451–55. http://dx.doi.org/10.3109/01913128909048495.

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2

Michelson, Alan D. "Gray platelet syndrome." Blood 121, no. 2 (January 10, 2013): 250. http://dx.doi.org/10.1182/blood-2012-09-455550.

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3

Bain, Barbara J., and Manju Bhavnani. "Gray platelet syndrome." American Journal of Hematology 86, no. 12 (July 28, 2011): 1027. http://dx.doi.org/10.1002/ajh.22055.

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4

Rosa, Jean-Philippe. "The gray platelet syndrome." Sang thrombose vaisseaux 26, no. 5 (September 2014): 240–54. http://dx.doi.org/10.1684/stv.2014.0854.

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5

Rosa, Jean-Philippe. "The gray platelet syndrome." Hématologie 19, no. 2 (March 2013): 123–35. http://dx.doi.org/10.1684/hma.2013.0793.

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6

Baruch, Dominique, Theo Lindhout, Evelyne Dupuy, and Jacques P. Caen. "Thrombin-Induced Platelet Factor Va Formation in Patients with a Gray Platelet Syndrome." Thrombosis and Haemostasis 58, no. 02 (1987): 768–71. http://dx.doi.org/10.1055/s-0038-1645967.

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SummaryThe present study was initiated to establish the functional factor V concentration in platelets of patients with a mild bleeding disorder ascribed to a gray platelet syndrome. This inherited platelet disorder has been characterized by a specific deficiency of alpha-granules and subsequent deficiencies in the alpha-granule proteins. We found that the concentration of plasma factor V was slightly decreased (70% of normal values). In contrast, platelet factor Va formation was severely impaired. Besides a much lower factor V content than in control platelets (10-20% of normal), the dependency of platelet factor Va formation on tlnumbin concentration was altered. Increasing the thrombin concentration 4-lold compared to the concentration that results in maximal factor Va generation from normal platelets did not result in a maximal factor Va formation from gray platelets. When a suspension of washed gray platelets was incubated with a prostacyclin analogue prior to the stimulation with thrombin, a 10-fold lower factor VQ activity was measured. Thus, thrombin-induced factor Va formation in a suspension of gray platelets is the result of a release reaction, followed by the thrombin-catalyzed activation of released factor V. Whereas the kinetics of the former reaction are apparently impaired, the kinetics of the latter one were found to be identical to those observed for normal platelet and plasma factor V activation.
7

Tubman, Venée N., Jason E. Levine, Dean R. Campagna, Rita Monahan-Earley, Ann M. Dvorak, Ellis J. Neufeld, and Mark D. Fleming. "X-linked gray platelet syndrome due to a GATA1 Arg216Gln mutation." Blood 109, no. 8 (January 5, 2007): 3297–99. http://dx.doi.org/10.1182/blood-2006-02-004101.

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AbstractWe identified a family with gray platelet syndrome (GPS) segregating as a sex-linked trait. Affected males had a mild bleeding disorder, thrombocytopenia, and large agranular platelets characteristic of GPS, while obligate carrier females were asymptomatic but had dimorphic platelets on peripheral smear. Associated findings included mild erythrocyte abnormalities in affected males. Linkage analysis revealed a 63 cM region on the X chromosome between markers G10578 and DXS6797, which segregated with the platelet phenotype and included the GATA1 gene. Sequencing of GATA1 revealed a G-to-A mutation at position 759 corresponding to amino acid change Arg216Gln. This mutation was previously described as a cause of X-linked thrombocytopenia with thalassemia (XLTT) but not of gray platelet syndrome. Our findings suggest that XLTT is within a spectrum of disorders constituting the gray platelet syndrome, and we propose that GATA1 is an upstream regulator of the genes required for platelet α-granule biogenesis.
8

Köhler, Michael. "Treatment of Gray Platelet Syndrome." Thrombosis and Haemostasis 60, no. 01 (1988): 123. http://dx.doi.org/10.1055/s-0038-1647649.

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9

Nurden, Paquita, Martine Jandrot-Perrus, Robert Combrié, Joelle Winckler, Veronique Arocas, Christelle Lecut, Jean-Max Pasquet, Thomas J. Kunicki, and Alan T. Nurden. "Severe deficiency of glycoprotein VI in a patient with gray platelet syndrome." Blood 104, no. 1 (July 1, 2004): 107–14. http://dx.doi.org/10.1182/blood-2003-11-3842.

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Abstract We report a novel case of gray platelet syndrome (GPS) where a severe deficiency of the platelet collagen receptor, glycoprotein (GP) VI, accompanies classical symptoms of a low platelet count and platelets lacking α-granules. Dense granules were normally present. Platelet aggregation with collagen was severely decreased, as was the response to convulxin (Cvx), a GPVI agonist. Quantitative analysis of GPVI using fluorescein isothiocyanate (FITC)–Cvx in flow cytometry showed its virtual absence on the patient's platelets. The GPVI deficiency was confirmed using monoclonal antibodies in Western blotting and in immunogold labeling on frozen thin sections where internal pools of GPVI were confirmed for normal platelets. The Fc receptor γ-chain, constitutively associated with GPVI in normal platelets, was present in subnormal amounts, and the phospholipase Cγ2–dependent activation pathway appeared to function normally. No autoantibodies to GPVI were found in the patient's serum using monoclonal antibody immobilization of platelet antigen (MAIPA). Sequencing of coding regions of the GPVI gene failed to show abnormalities, and mRNA for GPVI was present in the patient's platelets, pointing to a probable acquired defect in GPVI expression. Our results may provide a molecular explanation for the subgroup of patients with severely deficient collagen-induced platelet aggregation as previously described for GPS in the literature.
10

Rao, A. Koneti, and Deepak A. Rao. "Gray platelet syndrome: immunity goes awry." Blood 136, no. 17 (October 22, 2020): 1898–900. http://dx.doi.org/10.1182/blood.2020008196.

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Статті в журналах

Дисертації з теми "Gray platelet syndrome":

1

Delage, Laure. "Des déficiences génétiques comme modèles naturels pour l'étude de la régulation des checkpoints immunitaires et la caractérisation des réponses auto-immunes." Electronic Thesis or Diss., Université Paris Cité, 2021. http://www.theses.fr/2021UNIP5190.

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Des mutations récessives de NBEAL2 ont été décrites chez des patients atteints du syndrome des plaquettes grises (SPG). Ce syndrome se caractérise par une macro-thrombopénie, avec des plaquettes dénuées de granules-alpha, conduisant à des troubles de la coagulation, souvent associés à une splénomégalie. Ainsi, NBEAL2 a un rôle crucial dans le trafic des granules-alpha plaquettaires. En outre, notre laboratoire a montré que les patients avec un déficit en NBEAL2 peuvent présenter des caractéristiques cliniques semblables aux syndromes lymphoprolifératifs auto-immuns ; suggérant un rôle de NBEAL2 dans l'homéostasie immunitaire et la tolérance. Une cohorte internationale plus large de patients SPG a confirmé et décrit de nouvelles anomalies immunitaires chez ces patients (maladies auto-immunes, autoanticorps, lymphopénies). Si le rôle de NBEAL2 dans le trafic des granules est souvent étudié, le mécanisme exact conduisant au développement des manifestations auto-immunes chez les patients SPG reste inconnu. NBEAL2 appartient à une famille de protéines, impliquées dans le trafic vésiculaire, et possédant toutes un domaine BEACH conservé. Dans cette famille de protéines à domaine BEACH, une des protéines les plus proche de NBEAL2 est LRBA. LRBA est impliqué dans le recyclage de CTLA-4, un checkpoint immunitaire inhibiteur. CTLA-4 joue un rôle crucial dans la régulation des réponses immunitaires et la tolérance. Des mutations récessives de LRBA conduisent à des caractéristiques cliniques semblables aux déficiences partielles en CTLA-4 : auto-immunité, infiltrations lymphocytaires et lymphopénie B progressive. En condition physiologique, LRBA empêche la dégradation lysosomale de CTLA-4 et permet son recyclage à la membrane plasmatique. Par analogie avec LRBA, nous avons étudié l'importance de NBEAL2 dans le trafic intracellulaire des checkpoints immunitaires et nous avons apporté un nouveau regard sur son rôle dans les lymphocytes. NBEAL2 est ainsi une protéine d'échafaudage, se liant à LRBA, et impliquée dans le trafic de CTLA-4 ainsi que le trafic vésiculaire en général. Ces travaux apportent de nouvelles connaissances sur la régulation de CTLA-4 dans les lymphocytes T activés, une nouvelle liste de partenaires pour la protéine NBEAL2 ainsi qu'un nouveau modèle pour le trafic vésiculaire dans lequel est impliqué NBEAL2. Enfin, une meilleure compréhension des mécanismes conduisant à l'auto-immunité chez les patients atteints du syndrome des plaquettes grises pourrait conduire à un diagnostic plus précoce et un traitement adapté
Recessive NBEAL2 mutations have been reported in patients with Gray Platelet Syndrome (GPS). This syndrome is characterized by a macro-thrombocytopenia, with platelets lacking alpha-granules, leading to bleeding disorders, often associated with splenomegaly. Thus, NBEAL2 plays a crucial role in the trafficking of alpha-granules in platelets. Moreover, our lab has also described NBEAL2 deficiencies in patients presenting clinical features of the autoimmune lymphoproliferative syndrome, suggesting a role of NBEAL2 in immune homeostasis and tolerance. A broader international cohort of GPS patients has been described, revealing immune system abnormalities (autoimmune diseases, autoantibodies, lymphopenia). If the role of NBEAL2 in the traffic of granules is often investigated, the exact mechanism leading to the development of autoimmune manifestations in GPS patients remains unknown. NBEAL2 belongs to a protein family involved in vesicular trafficking, all of which possess a conserved BEACH domain. Within this BEACH-domain containing proteins family, one of the closest members to NBEAL2 is LRBA. LRBA is involved in the recycling of CTLA-4, an inhibitory immune checkpoint. CTLA-4 plays a crucial role in the regulation of immune responses and tolerance. Recessive mutations of LRBA lead to similar clinical features as partial CTLA-4 deficiency: autoimmunity, lymphocytic infiltrations, and progressive B lymphopenia. Physiologically, LRBA prevents the lysosomal degradation of CTLA-4 and allows its recycling to the membrane. By analogy with LRBA, we investigated the importance of NBEAL2 in immune checkpoints intracellular trafficking and we brought new insights on its role in lymphocytes. Thus, NBEAL2 is a scaffold protein, binding LRBA, and involved in CTLA-4 trafficking as well as in vesicular trafficking in general. This work brings new knowledge to the regulation of CTLA-4 in activated T lymphocytes, a list of new partners for NBEAL2 protein and a new model of vesicular trafficking in which NBEAL2 is involved. Finally, a better understanding of the mechanisms leading to autoimmunity in patients with gray platelets syndrome could lead to better diagnosis and treatment management

Частини книг з теми "Gray platelet syndrome":

1

Timson, David J., Richard J. Reece, James B. Thoden, Hazel M. Holden, Andrea L. Utz, Beverly M. K. Biller, Eugen-Matthias Strehle, et al. "Gray Platelet Syndrome." In Encyclopedia of Molecular Mechanisms of Disease, 758–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_735.

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2

Shahraki, Hojat, Akbar Dorgalaleh, and Barbara J. Bain. "Gray Platelet Syndrome (GPS)." In Congenital Bleeding Disorders, 379–96. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76723-9_16.

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3

Kianinodeh, Fatemeh, Maryam Sadat Hosseini, and Barbara J. Bain. "Gray Platelet Syndrome: Diagnosis and Management." In Congenital Bleeding Disorders, 445–63. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-43156-2_17.

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4

Vagts, Dierk A., Heike Kaltofen, Uta Emmig, and Peter Biro. "Grey-Platelet-Syndrom (UK)/Gray-Platelet-Syndrom (USA)." In Anästhesie bei seltenen Erkrankungen, 1–2. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-662-44368-2_108-1.

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5

Köhler, M. "Grey-platelet-Syndrom: Pathophysiologie, Klinik, Diagnostik und Therapie." In Hämostaseologie, 67–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-662-07673-6_9.

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6

"Gray Platelet Syndrome." In Diagnostic Pathology: Blood and Bone Marrow, 322–25. Elsevier, 2018. http://dx.doi.org/10.1016/b978-0-323-39254-9.50068-4.

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7

Pozdnyakova, Olga. "Gray Platelet Syndrome." In Hematopathology, 37–38. Elsevier, 2013. http://dx.doi.org/10.1016/b978-1-4377-1758-7.00016-6.

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Тези доповідей конференцій з теми "Gray platelet syndrome":

1

Levy-Toledano, S., J. Enouf, M. Lebret, R. Bredoux, and J. P. Caen. "ABNORMAL CALCIUM TRANSPORT INTO MICROSOMES OF GRAY PLATELET SYNDROME." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644747.

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Gray platelets initially described as lacking α granules also show thrombin-induced aggregation and release lower than normal. One of the possible explanation is a modified intracellular Ca2+ concentration which is involved in platelet activation. We then decided to investigate the relationship between the morphological abnormality and a possible regulation of platelet Ca2+ concentration.We isolated a platelet membrane fraction (100,000 g) enriched in intracellular membranes which actively sequesters Ca2+. This Ca2+ uptake was mediated by a characterized (Ca2+ + Mg2+) ATPase.The isolated membrane vesicles from two patients show an increase in the calcium uptake. The stimulation reaches a factor 2 to 3 agd the Ca2+ uptake appears greatly increased whatever the Ca concentration used. This led us to investigate the Ca2+ + Mg2+ ATPase activity. The enzymatic activity appears increased in the first 10 minutes which correlates with the increased rate in calcium uptake. The specific activity of the enzyme is increased by a factor 2.4 to 2.7 which again agrees with the calcium uptake results. Therefore we suggest that the severe impairment in secretion found in the Gray platelets is probably related to the low cytoplasmic mobilization as it is found by Hardisty et al, 1985 ; this would be the consequence of an increased Ca2+ uptake rather than a decrease in the Ca liberation.The absence of α granules in Gray platelets together with the described abnormality in internal membranes and the recently described modification of external membrane fluidity (Rendu et al 1985) would suggest that these platelets have a general membrane disorder.
2

Mori, K., S. Suzuki, K. Sugai, Y. Akutsu, M. Ishikawa, H. Sakai, and K. Hiwatashi. "INTRACELLULAR CA++ MOBILIZATION IN GRAY PLATELET SYNDROME. ELECTRONMICROSCOPIC STUDIES ON AEQUORIN LOADED PLATELETS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644558.

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Light microscopic examinations on platelets in Gray Platelet Syndrome(GPS) showed peculiar gray colored platelets due to deficiency in ^-granules on the peripheral blood smear by May-Grunwald-Giemsa stain. Besides α-granule deficiency, however, several morphological abnormalities, especially abnormal features of dense tubular system(DTS) etc., were recognized in the transmission electronmicroscopic examinations. In the platelet function tests, release abnormalities rather than storage-pool deficiency were noted. We were strongly interested in the relationships between these morphological and functional abnormalities, because DTS in the platelets have been thought to be main storage sites of intracellular Ca ion.We examined the intracellular Ca++ mobilization using aequo-rin loaded platelets by means of Lumi-aggregometer(Salzman's method) under the stimulation of A-23187 and thrombin, and also morphological changes of platelets during the process of platelet aggregation by light |ipd transmission electronmicroscope.Intracellular Ca concentration increased dose-dependently after addition of A-23187 in both normal and GPS platelets. Namely, besides the first peak of emission which located at the same site as normal control, the slowly appearing second peak were recognized on the trace line by the addition of A-23187 and also abnormal by thrombin in GPS platelets. Transmission electronmi-crographs showed insufficient contraction of platelet-aggregates and malformation or wide appearance of pseudopods by the addition of A-23187 and thrombin. Most of the contractile gels, which were usually seen in the center of the platelets, were slightly enlarged and eccentric in the position. Delayed intracellular Ca mobilization were also noted even in the buffer solution containing EGTA.From above mentioned results, intracellular Ca++ mobilization were abnormal and these low and delayed mobilization were thou -ght to be related with prominent abnormal morphology, especially abnormalities of DTS in the GPS platelets.
3

FACON, T., J. GOUPEMAND, C. CARON, M. ZANDECKI, M. H. ESTIENNE, and A. COSSON. "GRAY PLATELET SYNDROME AND IDIOPATHIC PULMONARY FIBROSIS OCCURRING IN THE SAME PATIENT : A FORTUITOUS ASSOCIATION?" In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644559.

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A 46 yr old Caucasian woman has been diagnosed as having a congenital deficiency of platelet a-granules (gray platelet syndrome - GPS) associated with an extensive idiopathic pulmonary fibrosis (IPF). The patient had a life long history of bleeding tendency including dental bleedings in childhood, intraperitoneal bleeding, metrorrhagias which led to hysterectomy, and post-operative hemorrhages. When aged 16, splenectomy was performed because of a mild thrombocytopenia but did not result in a subsequent improvement of the platelet count. The spleen was enlarged and showed an excess of fibrous tissue.Evaluation of hemostasis (July 1986) revealed a moderate thrombocytopenia of 120 × 109/1 constrasting with a markedly prolonged Simplate bleeding time (>30 min.). When examined on stained blood films, the platelets presented a "ghost-like" gray appearance. The mean platelet volume (coulter S + IV) was increased to 14 μ3 (N : 6.5-9.5 μ3). Ultrastructural studies confirmed the lack of a-granules and showed normal presence of dense-bodies, mitochondria and peroxisomes. Platelet aggregation was decreased when induced by thrombin, ADP and collagen but normal in response to arachidonic acid and ristocetin. A severely decreased content of platelet proteins such as fibrinogen, vWF:Ag, BTG and PF4. was further demonstrated. A bone marrow biopsy performed on March 1986 gave no evidence of myelofibrosis (occasionally recorded in GPS) but the patient developed for these last 6 years a severe IPF requiring a permanent oxygen-therapy. Although the association GPS-IPF might be only considered as a fortuitous one, we hypothesize that these two events might be related to each other, possibly through the presence of megakaryocytes in pulmonary capillaries, in the same way as bone marrow fibrosis has been suggested as a possible consequence of the lack of a-granules in GPS (DR0UET et al. - Nouv. Rev. Fr. Hematol., 1981, 23 : 95).
4

Legrand, C., V. Dubernard, N. Kieffer, and A. T. Nurden. "USE OF A MONOCLONAL ANTIBODY TO MEASURE THE SURFACE EXPRESSION OF THROMBOSPONDIN FOLLOWING PLATELET ACTIVATION." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643821.

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A radiolabelled monoclonal antibody (mAb) against native thrombospondin (TSP) has been used to quantitatively assess the surface exposure of intracellular TSP following platelet stimulation. This mAb, designated 5G11, was purified from ascitic fluid by ammonium sulfate precipitation followed by chromatogloghy on DEAE Trisacryl. The isolated IgG were labelled with I by the chloramine T method (sp.act. 200-500 cpm/ ng). The specificity of the mAb was established by immunoblot-ting and crossed immunoelectrophoresis using platelet protein extracts. When the labelled IgG (20 μg/ml) were incubated with resting platelets in Tyrode's buffer binding was of the order of 2,000 molecules per platelet. Binding was increased 2 fold and 5-7 fold respectively upon ADP- and thrombin-(or ionophore A23187) stimulation. Unactivated platelets from 2 patients with the Gray Platelet Syndrome bound baseline levels of 5G11, but binding did not increase after platelet activation. In the presence of saturating concentrations of mAb 5G11, an average of 30,000 molecules of IgG were bound by normal platelets stimulated by thrombin. This binding was strongly reduced in the presence of EDTA. It was not significantly affected by AP-2, an anti-GP IIb-IIIa monoclonal antibody which inhibited by more than 85% the binding of plasma fibrinogen but which did not inhibit the surface expression of platelet fibrinogen. It was decreased but not prevented by the presence of an excess of rabbit anti-fibrinogen Fab fragments during the stimulation, while binding at the lower end of the normal range was observed on two different occasions using platelets isolated from an afibrinogenemic patient lacking platelet fibrinogen. These results suggest that while platelet fibrinogen may contribute to the surface organization of TSP other component(s) are required for the full expression of TSP on the platelet surface.
5

Patscheke, H., and G. Mathieu. "MONITORING OF THE PLATELET ALPHA-GRANULE SECRETION IN THE AGGREGOMETER." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643492.

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If platelets are stimulated to secrete and the aggregation is prevented by EDTA and no stirring, the optical density (OD) decreases as a consequence of secretion (Patscheke et al. Thromb. Res. 33: 314, 1984). The purpose of this study was to determine which secretory compartment causes the change in OD and to analyze the quantitative relationship between decrease in OD and granule discharge. Human washed platelets were stimulated with thrombin and A 23187 in a Lumi-Aggregometer (Chrono-Log) which permitted simultaneous recording of the change in OD and of the ATP release from dense granules. At various time intervals, platelet factor 4 (PF-4), [3H)serotonin (5-HT), 8-N-ace-tylglucosaminidase (NAG) and lactate dehydrogenase (LDH) were determined in the supernatant as parameters of the release from the alpha granules, dense granules, lysosomes and the cytoplasm, respectively. In order to prevent the platelet shape change (increase in OD) from interfering with secretion (decrease in OD), the platelets were pretreated with 0.1 nM PAF 2 min prior to the secretagogue. PAF induced the shape change but no release of platelet constituents. The results show that the decrease in OD closely correlates with the release of PF-4. The fractional effects were identical in concentration-effect and time-effect studies. However, neither the decrease in OD nor the release of PF-4 were correlated with the release of ATP and 5-HT from the dense granules or the lysosomal release of NAG. The release of ATP and 5-HT required significantly higher agonist concentrations than the decrease in OD and the release of PF-4 and even higher concentrations were required for the release of NAG. LDH liberation did not exceed 1 % with 1 U/ml thrombin, indicating the absence of lysis. Thrombin 1 U/ml caused a maximum decrease in OD of 11 % and 40 % release of PF-4. In a patient with gray platelet syndrome, the decrease in OD was absent while the release of 5-HT was normal. These results show that the decrease in OD is due to alpha-granule secretion. The turbidimetric method offers a valuable tool for kinetic measurements of alpha-granule secretion. By using a Lumi-Aggregometer, secretion from alpha and dense granules can be monitored simultaneously. (Supported by the Deutsche Forschungsgemeinschaft, Grant Pa-263).
6

Forestier, F., F. Daffos, C. Kaplan, and P. Champeix. "PRENATAL DIAGNOSIS OF HEMORRHAGIC DISORDERS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644270.

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Utilizing an easy and safe procedure for fetal blood sampling in utero. we have studied 123 fetuses for congenital oracquire hemorrhagic disorders.Usually, the diagnosis is performed at the 18th week of gestation. To date, no fetal less or premature labor has beenattributed to these fetal samplings. Theduration of the procedure was less than 10 minutes in 90 % of the cases. Direct blood sampling with a needle guided by ultrasound is safer for fetuses and simpler for the patients than fetoscopy. Among the 1.465 samplings the mortality rateis 0.2 %. We have established the basis values for fetal hemostasis when the samplings were performed for non hematological purpose, and could determine the fetal sex which play a role in hereditary disorders. Hemophilia A and B [92 cases]. Willebrand disease, factor XIII, V and VII deficiencies were diagnosed on the existence of a specific fetal deficit. Theknowledge of the fetal primary hemostasis let us to establish the diagnosis of May Hegglin syndrome. Gray platelet syndrome. and Glanzmann's thrombasthenia. There were no diagnostic errors. This procedure offers a new possibility of easily taking iterative samples, until the end of pregnancy, which represents a particular interest in prenatal diagnosis.
7

Wautier, J. L., Y. Gruel, B. Boizard, J. P. Caen, F. Daffos, and F. Forestier. "ANTENATAL DIAGNOSIS OF THROMBOPATHY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644271.

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We previously determined platelet antigens and glycoproteins in the human fetus after 19 weeks of intrauterine life (Blood 68, 488-92,1986). These results obtained in fetuses with normal platelets allowed us to do the first attempt of antenatal diagnosis in Glanzmann thrombasthenia. The fetal propositus was tested with monoclonal (AP2, AP3) or polyclonalantibodies (IgGL) directed against GPIIbllla or platelets antigen (PLA1, Leka). The foetus was found to be heterozygous for GT and similar results were foundafter his birth.Grey platelet syndrome is a rare congenital platelet defect caracterized by an alpha granule deficiency and is transmitted on the dominant feature. To be able to detect this abnormality before birth we have measured the platelet content of alpha granules.The amount of Beta thromboglobulin (gTG) at 18 weeks of intrauterine life was32±4.3 mg/109 platelets in normal platelets (adults 60 mg/10^ platelets). The foetus of the mother with grey platelet syndrome was sampled at 19 weeks when the mother was under platelet transfusion and the platelets were studied by electron microscopy and for their BTG content. The platelet morphologyshowed the presence of alpha granules and the $TG content was in the range of the control fetuses (42mg/109 platelets). The baby was born after artificial delivery under platelet transfusion. These results showed that the antenatal diagnosis of thrombopathies is feasible and can permit a therapy to avoid dramatic haemorrhage during pregnancy or delivery.
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Cockbill, S. R., S. Heptinstall, and H. B. Burmester. "A PLASMA FACTOR FROM A PATIENT WITH A BLEEDING TENDENCY CAUSES PLATELET SECRETION IN THE ABSENCE OF EXTRACELLULAR CALCIUM." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643489.

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A woman with a history of bruising and bleeding but with a normal platelet count and normal clotting factors, had platelets that appeared grey when stained and viewed under the microscope. Unlike the grey-platelet syndrome, the abnormality was only evident when the blood had been collected into EDTA andnot when citrate or heparin was used as anticoagulant. When we examined the EDTA-blood further we found that large quantities of beta-thromboglobulin andserotonin (5HT) were present in the plasma with only small quantities in the platelets. Hie reverse was the case for blood collected into citrate or heparin. LDH (a cytoplasmic marker) levels in EDTA-plasma were not raised.Platelet-rich plasma (PRP) was prepared from blood collected into heparin and labelled with ^-4C-5HT. Incubating the PRP with EDTA (4mM) or EGTA (3mM, sufficient to chelate all the plasma calcium but not the magnesium) caused extensive release of 14C-5HT from the platelets. When Ca++ was removed by passing the PRP through an ion-exchange resin, extensive 14C-5HT release also occurred. Hie release reaction induced by exposing the platelets to a low-Ca++ environment could be prevented by agents that increase cAMP levels.In a series of cross-over experiments, we discovered that the platelet secretion that occurred on removing Ca++ was caused by a plasma factor. Platelets from a healthy donor which had been labelled with 14C-5HT were resuspended in the patient's heparinised plasma. Incubating the platelet suspension with EGTA resulted in extensive release of 14C-5HT. Heparinised plasma from the patient was also passed through a column of Protein A-Sepharose to remove the immunoglobulin fraction. EGTA-challengof control platelets resuspended in the eluted plasma did not cause any release of 14C-5HT, suggesting that the plasma factor responsible may be an immunoglobulin.We have yet to discover whether this new abnormality (that on initial investigation could be confused with the grey-platelet syndrome) has any relevance to the in vivo bleeding situation in the patient in whom it was discovered.
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Rendu, F., T. Hovig, P. Marche, M. Lebret, D. Tenza, J. Maclouf, J. P. Caen, and S. Levy-Toledano. "MEMBRANE SIGNAL TRANSDUCTION IN PLATELETS WITH ALTERED RELEASE REACTION." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644746.

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The process of signal transduction during thrombin-induced activation was studied in pathological platelets characterized by a defect in a specific storage granule, i.e. from Hermansky-Pudlak syndrome (HPS) and from Grey-Platelet Syndrome (GPS). HPS platelets exhibited an apparently normal ultrastructure except for a decreased number of dense bodies. Grey platelets showed marked vacuolization and an almost total absence of alpha-granules. During thrombin stimulation both types of platelets showed the same tendency of centralization of the organelles present indicating that neither type of granule is a prerequisite for this ring-like structure.However this granule centralization was clearly delayed in GPS where it occurred 15 sec after thrombin addition instead of 5 sec in normal platelets. The transducing system involving phosphoinositides specific phospholipase C was observed in platelets lacking dense bodies (HPS) but the phosphatidyl 4,5 bisphosphate(PIP2 )breakdown in 32P-prelabelled platelets was measurable at 202 sec instead of 10 sec in normal platelets. No ch activity was detectable at any time in grey platelets. 32P-phosphatidate (PA) formation was subnormal in HPS platelets and normal in grey platelets. Phosphorylation pattern of myosin light chain (P20) and of 43K protein (P43) were normal in HPS platelets and markedly reduced in grey platelets, being less than half of the normal during the first 15 sec and remaining subnormal even after complete aggregation. The release of constituents from the present granules and the thromboxane formation were lower than in normal platelets in all cases. In conclusions, (i) alpha-granules but not dense bodies may play a key role in the activation of the PIP2 specific phospholipase C,(ii) PA formation does not always correlate with phosphoinositide metabolism and could originate from another pool of diacylglycerol,(iii) complete phosphorylations of both P20 and P43 may not be sufficient to stimulate a normal release, and (iv) end products such as thromboxanes and released ADP accelerate and reinforce platelet responses.

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