RESUMO
Alloy-ceramic oxide multilayers of Ni(80)Nb(20)- MgO with 3.56-nm period have been made by use of the pulsed-laser deposition technique and characterized by means of grazing-incidence x-ray reflectivity. The interface roughness was found to be only ~0.35 nm at the two interfaces, Ni(80)Nb(20)- MgO and MgO-Ni(80)Nb(20), leading to a peak reflectivity of ~38% at the first order. The atomic structure in the two individual layers, Ni(80)Nb(20) and MgO, is found to be amorphous, in agreement with the deposition conditions. These multilayers can be used as mirrors for soft x rays in the angular range 18 degrees to 39 degrees , depending on the actual wavelength of radiation in the water-window region.
RESUMO
Serological and clinical data were collected in 348 cases of suspected neonatal alloimmune thrombocytopenia (NAT). Of the 144 mothers who were Zwa-negative, 107 had Zwa antibodies--alone (94); with HLA antibodies (12); or with Bra antibodies (1). Antibodies were detected in 12 of the 204 Zwa-positive mothers as follows: anti-Bra (9), anti-Zwb (1), anti-Baka with HLA antibody (1), and blood group B isoagglutinins (1). The frequency of NAT due to Bra incompatibility (19%) was second to Zwa (78%). Zwa-NAT was clinically the more severe (14% had intracranial haemorrhages) and responded well to either maternal platelet transfusions or intravenous IgG. In Bra-NAT intracranial haemorrhages were not observed and most children recovered without specific therapy.
Assuntos
Antígenos de Plaquetas Humanas , Incompatibilidade de Grupos Sanguíneos/imunologia , Plaquetas/imunologia , Isoantígenos/imunologia , Troca Materno-Fetal , Trombocitopenia/imunologia , Adolescente , Adulto , Hemorragia Cerebral/etiologia , Feminino , Antígenos HLA/imunologia , Humanos , Imunoglobulina G/uso terapêutico , Recém-Nascido , Integrina beta3 , Isoanticorpos/análise , Masculino , Contagem de Plaquetas , Transfusão de Plaquetas , Gravidez , Prognóstico , Trombocitopenia/complicações , Trombocitopenia/terapiaRESUMO
The analysis of sera containing different platelet-reactive antibodies, eg, autoantibodies, platelet-specific alloantibodies like anti-PIA1, -PIA2, -Baka, and HLA antibodies, is still difficult. Recently, monoclonal antibodies against major platelet membrane constituents (glycoproteins IIb/IIIa and Ib and HLA class I molecule) have become available. In this report we describe a new assay that takes advantage of these highly specific reagents to investigate selectively platelet reactive antibodies against epitopes on different glycoproteins. The reliability and specificity of this assay is demonstrated with known platelet-reactive autoantibodies and alloantibodies (anti-PIA1, -Baka, -Pen). The discovery of a PIA2 antibody in a serum of a polytransfused patient underscores the efficiency of this technique. Possible applications of this assay are discussed in detail.
Assuntos
Anticorpos Monoclonais , Antígenos de Superfície/imunologia , Autoanticorpos/análise , Plaquetas/imunologia , Técnicas de Imunoadsorção , Glicoproteínas da Membrana de Plaquetas/imunologia , Especificidade de Anticorpos , Epitopos , HumanosRESUMO
A case of neonatal alloimmune thrombocytopenia due to fetomaternal incompatibility against the platelet-specific antigen Zwb (PlA2) is described. The antibody was of the IgG class and did not fix complement in vitro. Its specificity was established by panel identification and by comparison to a Zwb antiserum. Gene dosage determinations of Zwa antigens on platelets of parents and child revealed that the mother was homozygous Zwa Zwa, while father and child were heterozygous for this antigen.
