Effects of blood type and blood handling on feeding success, longevity and egg production in the body louse, Pediculus humanus humanus.

The effects of feeding different types of human blood to human body lice, Pediculus humanus humanus L. (Phthiraptera: Pediculidae), on feeding success, longevity and numbers of eggs laid were investigated using an artificial blood-feeding system in the laboratory. No significant differences were found between lice fed on different human blood types for any of the parameters tested. However, when lice were fed on human blood of one blood type followed immediately by a different blood type, they took significantly smaller bloodmeals, their longevity was reduced and they laid fewer eggs per female than control lice that had been fed twice on the same human blood type. When lice were fed human blood that had been stored for 1-26 weeks, the quantity of blood taken, the proportion of lice that became fully engorged and lice longevity diminished gradually as the storage time of the blood increased, but there was no effect of storage time on the mean number of eggs laid per female. However, lice would not feed on 26-week-old blood. The type of anticoagulant used had a significant effect on the proportion fed, longevity and number of eggs laid per female. Generally, EDTA (ethylenediaminetetraacetic acid)-treated blood reduced longevity and the number of eggs laid per female to a greater degree than heparinized or citrated blood. Lice fed on rabbit blood took significantly larger amounts of blood, lived longer and laid a higher mean number of eggs per female than lice fed on human blood.

Bone marrow stromal cells prepared using AB serum and bFGF for hematopoietic stem cells expansion.

BACKGROUND: An ex vivo culture system was previously established for stem cell expansion using human marrow stromal cells and serum-free medium. However, the stromal cells were prepared using long-term culture medium containing horse serum and FCS, which may transmit infectious diseases of xenogeneic origin. In this study, therefore, a method was established to prepare stromal cells using an AB serum-based medium. In the case that serum from a transplant recipient or PBPC donor is available, additional infectious diseases would not be transmitted. STUDY DESIGN AND METHODS: Cord blood CD34+ cells were cultured with thrombopoietin, stem cell factor, and flt3/flk2 ligand on a monolayer of human marrow primary stromal cells prepared using long-term culture medium or AB serum-based medium. After 2 weeks, clonogenic progenitor activity and SCID mouse-reconstituting cell activity were assayed. mRNA expression of cytokines and Notch ligand by stromal cells was also examined. RESULTS: There were no remarkable differences in expansion-supporting activity and mRNA expression between stromal cells established by the two methods. CONCLUSION: An ex vivo expansion system completely based on AB serum has been established.

Adhesion of Candida albicans, but not Candida krusei, to salivary statherin and mimicking host molecules.

The aim of the present study was to identify salivary molecules affecting adhesion of Candida albicans and Candida krusei to salivary pellicles and epithelial cells. Strains of C. albicans (GDH18, GDH3339, CA1957, ATCC 28366 and ATCC 10321), but not C. krusei (strains ATCC 14243 and Ck9), bound to saliva-coated hydroxyapatite and buccal epithelial cells. Parotid saliva fractions containing statherin, glycosylated proline-rich proteins (PRP) and as yet unidentified components mediated adhesion of strain GDH18; Fuc alpha 1-2Gal beta 1-4Glc partly inhibited the adhesion to those fractions not containing statherin. Pure statherin, but not PRP-1, mediated dose-dependent adhesion of C. albicans strain GDH18 to hydroxyapatite beads. Candida isolates (GDH18, GDH3339 and CA1957) bound somewhat more avidly to statherin/saliva relative to ATCC strains 28366 and 10321, while the opposite was true for adhesion to buccal epithelial cells. Adhesion of C. albicans strain GDH18 to saliva-coated hydroxyapatite and buccal epithelial cells was completely (93%) and partly (43%) blocked by statherin-specific immunoglobulin G (IgG) antibodies, respectively. Control IgG antibodies did not block Candida adhesion. Blockage of Candida adhesion to epithelial cells also occurred with Fuc alpha 1-2Gal beta 1-4Glc (49%) and N-acetylglucosamine (38%), while statherin specific IgG antibodies in combination with Fuc alpha 1-2Gal beta 1-4Glc almost completely eliminated Candida adhesion (79%). In addition, statherin in solution blocked the adhesion of strain GDH18 to epithelial cells by inducing aggregation of Candida cells.

Hemagglutinins in fungus extracts and their blood group specificity.

A total of 833 fungi harvested from 1977 to 1994 were tested and 422 extracts (47.8%) produced hemagglutination of human red cells. The lectins in fungus extracts which showed blood-group-specific or related reactions were partially purified by ammonium sulfate precipitation and gel filtration on a Sephadex G-100 column. Anti-H-like agglutinins were found in extracts of Pleurocybella porrigens, Naematoloma sublateritium and Pholiota squarrosa. These extracts agglutinated strongly with human group O red cells and rather weakly with A and B cells. Anti-A agglutinins were found in extracts of Hohenbuehelia serotina, Paxillus panuoides, Melanoleuca melaleuca and Hygrophorus capreolarius. The extract of Clavulinopsis fusiformis contained anti-B agglutinin. The ABH reactivities of the extracts were cofirmed by an agglutination inhibition test with ABH secretor saliva and blood group substances from human gastric linings and by the destruction of inhibiting activity using blood-group-specific decomposing enzymes. L-Fucose was the most active inhibiting monosacharide of anti-H-like agglutinins. The reaction of anti-A agglutinins was strongly inhibited by N-acetyl-D-galactosamine. D-Galactose and raffinose and melibiose which contain alpha-galactosyl residues were potent inhibitors of C. fusiformis agglutinin.

Epitope specificity of blood-group-A-reactive murine monoclonal antibodies.

Monoclonal antibodies (MABs) towards blood groups A manifested three broad patterns of binding distinguished on the basis of affinities for A1 or A2B phenotype red blood cells and blood group substances. Competitive inhibition of binding of radiolabelled MABs by other unlabelled antibodies and absorption studies with synthetic haptens suggested that GpA specificity was expressed as two topographically related structures, one being the terminal GpA trisaccharide and the second probably involving part of the oligosaccharide backbone. The enhancement of binding of an extremely low-affinity antibody by higher affinity antibodies recognising either epitope indicated a topographic, possibly conformational relationship between these epitopes. It is suggested that only those antibodies that recognise terminal GpA trisaccharides can agglutinate weak A2B cells.

Enhancement of lymphocyte response to PHA by lysosomal enzymes from polymorphonuclear leukocytes of RA joint fluid. I. Biological effect on T lymphocyte function.

The effect of polymorphonuclear leukocyte (PMN) granule lysates obtained from joint fluid of RA on the in vitro DNA synthesis of PHA-stimulated autologous lymphocytes from joint fluid was studied. Lymphocytes were cultured for 3 days with or without PMN lysates in 2 ml of RPMI-1640 supplemented with 10% heat-inactivated fetal calf serum (FCS). The lymphocytes were stimulated with phytohemagglutinin (PHA-M). The DNA synthesis was measured by counting the [3H]thymidine incorporation. Lymphocytes from RA joint fluid stimulated with PHA-M showed 19,466+/-987 cpm (mean+/-SE) per 10(6) cells in the absence of PMN lysates. Upon addition PMN lysates to the PHA-stimulated lymphocytes, the maximum in vitro DNA synthesis increased to 44,877+/-1338 cpm. The enhancing effect of PMN lysates was abolished by plasma inhibitors or by passage through a column of protease inhibitor (Trasylol). It was concluded, therefore, that the enhancing effect of PMN lysates on PHA-stimulated lymphocytes may be associated with lysosomal proteases. Based on experiments using separated T and B lymphocytes, the enhancing effect of PMN lysates was considered to result from the activation of T lymphocytes. The results obtained in the present study suggest an important role for lysosomal proteases in the perpetuation of rheumatoid synovitis.

Chromium-51 release from human blood platelets by anti A antibody.

Platelets were obtained by differential centrifugation from Group A donors and were incubated with Na2-51Cr04. After washing to remove excess chromium, the platelets were exposed for one hour to Anti A antibody which showed agglutinating activity only. Chromium release was no greater than that of controls. Hemolytic Anti A in the presence of rabbit complement released 15 percent more chromium than controls. Anti P1A1, a platelet specific antibody, when incubated with platelets in the presence of rabbit complement released 45 percent more chromium than controls. It appears that Anti A antibody is not as destructive to platelets as a platelet specific antibody is, even when the Anti A antibody shows hemolytic activity with red cells. These observations are in agreement with previous in vivo studies of ABO incompatible platelets.