ABSTRACT
INTRODUCTION: Diagnosis of von Willebrand disease (VWD) is difficult due to the heterogenic phenotype of patients and to the complex tests that are required for an adequate investigation. The collagen binding assay (VWF:CB) reveals the adhesion capacity of von Willebrand factor (VWF) to collagen and can be useful to reduce the misleading diagnosis of VWD. This study aimed the standardization of 2 nonautomated VWF:CB assays based on ELISA and flow cytometry. METHODS: Plasma samples from 87 patients previously diagnosed with VWD and 22 healthy controls were analyzed. Measurement of the VWF-collagen binding activity was performed using a commercial assay and the 2 tests proposed. VWF:CB/VWF:Ag ratio was calculated for samples and the differentiation between types 1, 2A, and 2M was analyzed. RESULTS: ELISA and flow cytometry tests presented strong correlation with the gold standard test (r2 = .8976 and r2 = .8143, respectively). Tests based on ELISA and flow cytometry presented a bias of +7.2% and -3.6%, respectively. CONCLUSION: The ELISA test demonstrated better performance to detect VWF-collagen binding activity in healthy individuals and VWD patients. This test could differentiate 2A and 2M subtypes using a feasible protocol that can be easily implemented.
ABSTRACT
PIP: This is a general review of trends in migration in Italy from 1500 to 1900. The author examines questions concerning the definition of migration, problems with data sources, the characteristics of internal migration, and the factors influencing emigration.^ieng
Subject(s)
Data Collection , Emigration and Immigration , Population Dynamics , Demography , Developed Countries , Europe , Italy , Population , ResearchABSTRACT
Previous reports have described profound effects on the function of the lymphoid system, especially the spleen, in mice infected with Trypanosoma brucei. This study provides further evidence of major change in the cell populations of the blood, peritoneum, and bone marrow, but shows that at least some of the stem cells of the bone marrow survive the damage caused by trypanosomes and retain their ability to repopulate the animal. In these infected mice the initial parasitemia was terminated by day 11 and was followed by a subpatent period of approximately 7 days before a final, lethal parasitemia occurred. Lymphopenia preceded the initial and final waves of parasites in the blood, and there was a marked increase in circulating neutrophils and large mononuclear cells for 1 week after the termination of the first wave of bloodstream parasitemia and during the final lethal parasitemia. Dividing macrophages were detected in the peritoneum only briefly during week 1 of infection, but the total number of peritoneal cells was increased from day 8 until the mice died. The bone marrow is severely stressed by the parasite infection. Total cell numbers and spleen colony-forming cells in the bone marrow were profoundly depleted during the resolution of the first parasitemia, but both these parameters largely recovered during the subpatent period before the mice were killed by the disease. Immune function was restored gradually after treatment with Berenil late in infection. We conclude that the progenitors of lymphocytes as well as the mature cells are affected by trypanosomes, but that some of the early bone marrow stem cells escape and rapidly repopulate the peripheral organs upon removal of the parasites.