Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder characterized by qualitative or quantitative abnormalities of the platelet membrane glycoprotein (GP) IIb/IIIa. Physiologically, this platelet receptor normally binds several adhesive plasma proteins, and this facilitates attachment and aggregation of platelets to ensure thrombus formation at sites of vascular injury. The lack of resultant platelet aggregation in GT leads to mucocutaneous bleeding whose manifestation may be clinically variable, ranging from easy bruising to severe and potentially life-threatening hemorrhages. In this review we discuss the main characteristics of GT, focusing on molecular defects, diagnostic evaluation and treatment strategies.
"Dental extractions and other invasive procedures are frequently complicated by excessive bleeding. Platelet aggregation in the presence of ristocetin and absence of platelet aggregation in the presence of ADP, epinephrine, collagen and thrombin will confirm the diagnosis of GT. Flow cytometry can also be used in GT to detect the presence of the IIb-IIIa GP complex, GPIIb (CD41), GPIIIa (CD61) and fibrinogen using monoclonal antibodies. "
[Show abstract][Hide abstract] ABSTRACT: Glanzmann's thrombasthenia (GT) is an autosomal recessive inherited platelet function defect characterized by normal platelet count, prolonged bleeding time and abnormal clot retraction. This disease typically presents in infancy or early childhood and has proven to have very good prognosis. In this case study, a 22-year-old GT patient who also developed human immunodeficiency virus (HIV) infection after sometime is reported. The patient showed oral manifestations of gingival hyperplasia and petechial lesions. Unfortunately the detection of both thrombasthenia and HIV were done at considerably late stages which contributed to a poor prognosis. The patient died of cardiopulmonary arrest secondary to HIV, thrombasthenia and thrombocytopenia. The importance of early detection, supportive care and communication between the general and oral physician in management of the GT is also discussed.
International journal of preventive medicine 04/2014; 5(4):500-4.
[Show abstract][Hide abstract] ABSTRACT: Background
While the ability of bacteriophages to kill bacteria is well known and has been used in some centers to combat antibiotics – resistant infections, our knowledge about phage interactions with mammalian cells is very limited and phages have been believed to have no intrinsic tropism for those cells.
Presentation of the hypothesis
At least some phages (e.g., T4 coliphage) express Lys-Arg-Gly (KGD) sequence which binds β3 integrins (primarily αIIbβ3). Therefore, phages could bind β3+ cells (platelets, monocytes, some lymphocytes and some neoplastic cells) and downregulate activities of those cells by inhibiting integrin functions.
Testing the hypothesis
Binding of KGD+ phages to β3 integrin+ cells may be detected using standard techniques involving phage – mediated bacterial lysis and plaque formation. Furthermore, the binding may be visualized by electron microscopy and fluorescence using labelled phages. Binding specificity can be confirmed with the aid of specific blocking peptides and monoclonal antibodies. In vivo effects of phage – cell interactions may be assessed by examining the possible biological effects of β3 blockade (e.g., anti-metastatic activity).
Implication of the hypothesis
If, indeed, phages can modify functions of β3+ cells (platelets, monocytes, lymphocytes, cancer cells) they could be important biological response modifiers regulating migration and activities of those cells. Such novel understanding of their role could open novel perspectives in their potential use in treatment of cardiovascular and autoimmune disease, graft rejection and cancer.
Medical Immunology 03/2003; 2(1):2. DOI:10.1186/1476-9433-2-2
[Show abstract][Hide abstract] ABSTRACT: Cell adhesion and migration are essential for embryonic development, tissue regeneration, and immune defence. The physical link between the extracellular substrate and the actin cytoskeleton is mediated by receptors of the integrin family and a large set of adaptor proteins. During cell migration this physical link is dynamically modified, allowing the cell to sense and adapt to the microenvironment. This includes the formation of integrin clusters at the cell front, their stabilization in the cell body and subsequent disassembly of these clusters at the rear of the cell. The modulation of the adhesion strength of the cell to the substrate is regulated by the affinity switch of integrin molecules and increased avidity through clustering of integrins. Here we explain how integrins mediate cell migration and how genetic defects of integrins and their adaptors lead to cellular dysfunction and generate pathological situations.
The Journal of Pathology 07/2003; 200(4):481-7. DOI:10.1002/path.1399 · 7.43 Impact Factor
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