Human leucocyte antigens A,B, C,and DRW in idiopathic "warm" autoimmune haemolytic anaemia.

Twenty patients with idiopathic "warm" autoimmune haemolytic anaemia and 40 controls were types concurrently for human leucocyte antigens (HLA) A, B, C, and DRW. There was a significantly stronger association of HLA-B8 with the disease (chi 2 = 10.39; p = 0.018) than HLA-DRW3 (chi 2 = 3.71; P = 0.35) and the patients also showed a significant increase in BW6 homozygosity (chi 2 = 7.13; P = 0.01) and a corresponding reduction in BW4 (chi 2 = 7.13; P = 0.02). (All p values corrected for number of antigens at each locus.) These findings suggest that susceptibility to idiopathic autoimmune haemolytic anaemia is associated more closely with the HLA-B locus than with DRW3.     

Activation of rat B lymphocytes. II. Functional and structural changes in "aged" rat B lymphocytes

Anti-mu, anti-gamma, and anti-delta antibodies induce proliferation of splenic B lymphocytes from young Lewis rats, measured by 3H-TdR uptake. In contrast, splenic B cells of aged Lewis rats respond poorly or not at all to these reagents. T lymphocytes or interleukin 2 (IL-2) of young or aged rats augment the uptake of 3H-TdR in cultures of "young" B cells responding to anti-Ig reagents or LPS and DxS, but have no significant effect on the responses of "old" B cells. Analysis of spleen cells of young and aged rats in a fluorescence-activated cell sorter indicates the density of mu, gamma, and delta isotypes is reduced in "old" B cells, and that B cells of aged rats are significantly larger than those of young rats. These results delineate anatomic and structural changes in B lymphocytes of aged rats.     

Splenic modifications induced by cyclophosphamide in C3H/He, nude, and "B" mice.

The spleen cell population of adult C3H/He mice injected with a single sublethal dose of cyclophosphamide (CY) has been analyzed. An initial phase of spleen atrophy is followed by a considerable hypertrophy, and a progressive return to normal. During the phase of spleen atrophy, both B and T cell compartments are depleted, as estimated by the percentages of cells killed by anti-Thy 1-2 and anti-Ig antisera plus complement. During the stage of regeneration, the percentage of Ig + cells increases rapidly, and at the peak of splenomegaly, the percentage of Ig + cells is high whereas almost no Thy 1-2 + cells are detectable. Progresively, the spleen cell content returns to the original values. In thymo-deprived mice (nude mice and B mice) the percentage of null cells increases during the stage of regeneration, and B mice develop a large number of Ig +-bearing cells. Histologic examination shows that follicles (B-dependent areas) disappear 1 to 2 days before periarteriolar sheaths (T-dependent areas). At the peak of splenomegaly the architecture of the spleen is destroyed, and the interstitial tissue is composed of a dense and uniform layer of lymphoid cells. Progressively, the architecture returns to normal. In nude mice, the disappearance of follicles, and the appearance of a homogenous layer of lymphocytes has been observed. When analyzed for their pattern of electrophoretic mobilities (E.M.), spleen cells from untreated mice reveal two peaks of E.M. 0.80 and 1.15 micron x s-1 x V-1 x cm-1. After CY treatment, during the step of splenic hypertrophy, these two peaks disappear, and a single peak of intermediate mobility appears. In T-deprived mice, a single peak of the same mobility is detected at this stage. The nature and origin of cells which appear during the phase of regeneration are unclear, but their appearance in T-deprived mice argues against thymo dependence. These spleen cells have the ability to suppress the response of normal spleen lymphocytes to T and B cell mitogens.     

Novel identification and differentiation of Brucella melitensis, B. abortus, B. suis, B. ovis, B. canis, and B. neotomae suitable for both conventional and real-time PCR systems

We describe the development of a novel PCR assay for the rapid detection of members of the Brucella genus, and the differentiation between six recognized Brucella species. The assay has proven to be highly specific with the additional advantage of being suitable for use with both conventional and real-time PCR.     

Burkholderia species in human infections in Mexico: Identification of B. cepacia,B. contaminans,B. multivorans,B. vietnamiensis,B. pseudomallei and a new Burkholderia species

BackgroundBurkholderia sensu stricto is comprised mainly of opportunistic pathogens. This group is widely distributed in the environment but is especially important in clinical settings. In Mexico, few species have been correctly identified among patients, most often B. cepacia is described.Methodology/Principal findingsIn this study, approximately 90 strains identified as B. cepacia with the VITEK2 system were isolated from two medical centers in Mexico City and analyzed by MLSA, BOX-PCR and genome analysis. The initial identification of B. cepacia was confirmed for many strains, but B. contaminans, B. multivorans and B. vietnamiensis were also identified among clinical strains for the first time in hospitals in Mexico. Additionally, the presence of B. pseudomallei was confirmed, and a novel species within the B. cepacia complex was documented. Several strains misidentified as B. cepacia actually belong to the genera Pseudomonas, Stenotrophomonas and Providencia.Conclusions/SignificanceThe presence of different Burkholderia species in Mexico was confirmed. Correct identification of Burkholderia species is important to provide accurate treatment for immunosuppressed patients.