Isolation of mononuclear leukocytes in a plastic bag system using Ficoll-Hypaque

Development of PCR-ELISA for the detection of hepatitis B virus x gene expression and clinical application

The presence of hepatitis B virus x (HBx) antigen/antibody is known to correlate with the well-established serological markers of ongoing viral replication in the chronic phase of HBV infection, and strongly suggests that the level and duration of HBx expression may influence the outcome of the chronic infection. In this research, we developed a polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) method for the detection of HBx gene expression. We also investigated its relationship to the progress of the disease in HBV-related patients. Peripheral blood mononuclear cells (PBMCs) were purely isolated, and reverse transcription-PCR (RT-PCR) was performed for improved sensitivity. The PCR products were determined by ELISA, and we investigated the relationship of the proposed method to the clinical status of the patients. The PCR-ELISA used in this work was found to be at least 100 times more sensitive than the conventional PCR method, and even 8,000-fold diluted PCR products could be detected. The HBx concentrations significantly differed among control subjects (0.36+/-0.09, [P<0.01] and patients with chronic hepatitis (1.13+/-0.34 [P<0.01 compared to control]), liver cirrhosis (LC; 1.37+/-0.28 [P<0.01 compared to control]), and hepatocellular carcinoma (HCC; 1.48+/-0.95 [P<0.01 compared to control]). These findings suggest that monitoring of HBx could be useful for early diagnosis and prognosis in patients with chronic HBV infection, LC, and HCC.

Development of an aqueous-space mixing assay for fusion of granules and plasma membranes from human neutrophils

Several models have been developed to study neutrophil degranulation. At the most basic level, phospholipid vesicles have been used to investigate the lipid interactions occurring during membrane fusion. The two major forms of assays used to measure phospholipid vesicle fusion are based either on the dilution of tagged phospholipids within the membrane of the two fusing partners or the mixing of the aqueous contents of the vesicles. Although problems exist with both methods, the latter is considered to be more accurate and representative of true fusion. Using 8-aminonaphthalene-1,3,6-trisulphonic acid (ANTS) as a fluorescent marker, we have taken advantage of the quenching properties of p-xylenebispyridinium bromide ('DPX') to develop a simple aqueous-space mixing assay that can be used with any sealed vesicle. We compared our new assay with more conventional assays using liposomes composed of phosphatidic acid (PA) and phosphatidylethanolamine (PE), obtaining comparable results with respect to Ca2+-dependent fusion. We extended our studies to measure the fusion of neutrophil plasma-membrane vesicles as well as azurophil and specific granules with PA/PE (1:3) liposomes. Both specific granules and plasma-membrane vesicles fused with PA/PE liposomes at [Ca2+] as low as 500 microM, while azurophil granules showed no fusion at [Ca2+] as high as 12 mM. These differences in the ability of Ca2+ to induce fusion may be related to differences observed in whole cells with respect to secretion.

Autologous bone marrow transplantation

Autologous bone marrow transplantation has become a very popular and successful treatment for many patients with lymphomas and other malignancies. The current indications, pretreatment regimes, and laboratory manipulations are discussed as well as the application of gene transfer to eliminate selected genetic diseases and detect disease relapse.

Density gradient isolation of peripheral blood mononuclear cells using a blood cell processor

Large numbers of mononuclear cells (MNC) are needed for hematologic reconstitution using peripheral blood stem cells. The possibility of isolating those cells by discontinuous Ficoll-diatrizoate density gradient centrifugation in two blood cell processors (the Haemonetics V50 [V50] and the Cobe 2991 [2991]) were examined. Buffy coats from peripheral blood containing 6.23 X 10(8) MNC were separated in the V50, resulting in a recovery of 75 percent. The purity of the cells, defined as the percentage of lymphocytes and monocytes among all leukocytes, was 95 percent. With larger cell loads (3 to 7 X 10(9) MNC), the yield was higher in the V50 than in the Cobe 2991 (92 versus 75%). After separation in the V50 or the 2991, the cloning efficiencies of hematopoietic progenitor cells (CFU-GM and BFUe) were not different from those of cells isolated on 5 ml Ficoll-diatrizoate gradients in centrifuge tubes. Both leukapheresis and MNC separation can be carried out with the same bowl and tubing set in the V50. With that approach, an average of 6 X 10(9) MNC were processed in 16 experiments. An average recovery of 82 percent with 95 percent purity was achieved. The authors conclude that, in terms of simplicity of operation, cost effectiveness, and maintenance of sterility, the V50 may be better suited than the 2991 for the purification of MNC from peripheral blood.