Self-trapping transition for nonlinear impurities embedded in a Cayley tree

The self-trapping transition due to a single and a dimer nonlinear impurity embedded in a Cayley tree is studied. In particular, the effect of a perfectly nonlinear Cayley tree is considered. A sharp self-trapping transition is observed in each case. It is also observed that the transition is much sharper compared to the case of one-dimensional lattices. For each system, the critical values of $\chi$ for the self-trapping transitions are found to obey a power-law behavior as a function of the connectivity $K$ of the Cayley tree.Comment: 6 pages, 7 fig

Platelet Antibody Detection By Flow Cytometry: An Effective Method To Evaluate And Give Transfusional Support In Platelet Refractoriness

Background: Immune platelet refractoriness is mainly caused by human leukocyte antigen antibodies (80- 90% of cases) and, to a lesser extent, by human platelet antigen antibodies. Refractoriness can be diagnosed by laboratory tests and patients should receive compatible platelet transfusions. A fast, effective and low cost antibody-screening method which detects platelet human leukocyte/platelet antigen antibodies is essential in the management of immune platelet refractoriness. Objective: The aim of this study was to evaluate the efficiency of the flow cytometry platelet immunofluorescence test to screen for immune platelet refractoriness. Methods: A group of prospective hematologic patients with clinically suspected platelet refractoriness treated in a referral center in Campinas, SP during July 2006 and July 2011 was enrolled in this study. Platelet antibodies were screened using the flow cytometry platelet immunofluorescence test. Anti-human leukocyte antigen antibodies were detected by commercially available methods. The sensitivity, specificity and predictive values of the immunofluorescence test were determined taking into account that the majority of antiplatelet antibodies presented human leukocyte antigen specificity. Results: Seventy-six samples from 32 female and 38 male patients with a median age of 43.5 years (range: 5-84 years) were analyzed. The sensitivity of the test was 86.11% and specificity 75.00% with a positive predictive value of 75.61% and a negative predictive value of 85.71%. The accuracy of the method was 80.26%. Conclusion: This study shows that the flow cytometry platelet immunofluorescence test has a high correlation with the anti-human leukocyte antigen antibodies. Despite a few limitations, the method seems to be efficient, fast and feasible as the initial screening for platelet antibody detection and a useful tool to crossmatch platelets for the transfusional support of patients with immune platelet refractoriness.354252255Rebulla, P., Refractoriness to platelet transfusion (2002) Curr Opin Hematol., 9 (6), pp. 516-520Vassallo, R.R., New paradigms in the management of alloimmune refractoriness to platelet transfusions (2007) Curr Opin Hematol., 14 (6), pp. 655-663Pavenski, K., Freedman, J., Semple, J.W., HLA alloimmunization against platelet transfusions: Pathophysiology, significance, prevention and management (2012) Tissue Antigens., 79 (4), pp. 237-245Doughty, H.A., Murphy, M.F., Metcalfe, P., Rohatiner, A.Z., Lister, T.A., Waters, A.H., Relative importance of immune and non-immune causes of platelet refractoriness (1994) Vox Sang., 66 (3), pp. 200-205Legler, T.J., Fischer, I., Dittmann, J., Simson, G., Lynen, R., Humpe, A., Frequency and causes of refractoriness in multiply transfused patients (1997) Ann Hematol., 74 (4), pp. 185-189Ferreira, A.A., Zulli, R., Soares, S., Castro, V., Moraes-Souza, H., Identification of platelet refractoriness in oncohematologic patients (2011) Clinics (Sao Paulo)., 66 (1), pp. 35-40He, Y., Zhao, Y.X., Zhu, M.Q., Wu, Q., Ruan, C.G., Detection of autoantibodies against platelet glycoproteins in patients with immune thrombocytopenic purpura by flow cytometric immunobead array (2013) Clin Chim Acta., 415, pp. 176-180van Velzen, J.F., Laros-van Gorkom, B.A., Pop, G.A., van Heerde, W.L., Multicolor flow cytometry for evaluation of platelet surface antigens and activation markers (2012) Thromb Res., 130 (1), pp. 92-98Armitage, P., Berry, G., Mathews, J.N.S., (1987) Statistical methods in medical research, p. 559. , 2nd ed, Boston, MA: Blackwell ScienceAltman, D., (1990) Practical statistics for medical research, p. 624. , London: Chapman and HallKerkhoffs, J.L., Eikenboom, J.C., Schipperus, M.S., van Wordragen-Vlaswinkel, R.J., Brand, R., Harvey, M.S., A multicenter randomized study of the efficacy of transfusions with platelets stored in platelet additive solution II versus plasma (2006) Blood., 108 (9), pp. 3210-3215Sacher, R.A., Kickler, T.S., Schiffer, C.A., Sherman, L.A., Bracey, A.W., Shulman, I.A., Transfusion Medicine Resource Committee. Management of patients refractory to platelet transfusion (2003) Arch Pathol Lab Med., 127 (4), pp. 409-414. , College of American PathologistsDuquesnoy, R.J., Structural epitope matching for HLA-alloimmunized thrombocytopenic patients: A new strategy to provide more effective platelet transfusion support? (2008) Transfusion, 48 (2), pp. 221-227. , Comment in: Transfusion. 2008;48(2):204-6Heal, J.M., Blumberg, N., Masel, D., An evaluation of crossmatching, HLA, and ABO matching for platelet transfusions to refractory patients (1987) Blood., 70 (1), pp. 23-30. , JulMickey, R., Donor pool sizes for HLA matching (1989) Transfusion., 29 (4), pp. 285-286O'Connell, B.A., Lee, E.J., Rothko, K., Hussein, M.A., Schiffer, C.A., Selection of histocompatible apheresis platelet donors by cross-matching random donor platelet concentrates (1992) Blood., 79 (2), pp. 527-531Petz, L.D., Garratty, G., Calhoun, L., Clark, B.D., Terasaki, P.I., Gresens, C., Selecting donors of platelets for refractory patients on the basis of HLA antibody specificity (2000) Transfusion, 40 (12), pp. 1446-1456. , Comment in: Transfusion. 200040(12):1425-6Hod, E., Schwartz, J., Platelet transfusion refractoriness (2008) Br J Haematol., 142 (3), pp. 348-360Brooks, E.G., McPherson, B.R., Fung, M.K., Validation of HLAMatchmaker algorithm in identifying acceptable HLA mismatches for thrombocytopenic patients refractory to platelet transfusions (2008) Transfusion., 48 (10), pp. 2159-216

Vox Sanguinis International forum on the selection and preparation of blood components for intrauterine transfusion.

Research into fetal development and medicin

International Forum on Policies and Practice for Transfusion of ABO and RhD Non-Identical Platelets: Summary

Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

International Forum on Policies and Practice for Transfusion of ABO and RhD Non-Identical Platelets: Responses

Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease