Effects of simulated weightlessness on cellular morphology and biological characteristics of cell lines SGC-7901 and HFE-145.

We investigated the effects of simulated weightlessness on cellular morphology, proliferation, cell cycle, and apoptosis of the human gastric carcinoma cell line SGC-7901 and the human gastric normal cell line HFE-145. A rotating clinostat was used to simulate weightlessness. The Image-Pro4.5 image analysis system was used for morphometric analysis. Proliferating cell nuclear antigen expression was examined by immunohistochemical staining. Changes in the cell cycle were examined using a cytometer. Apoptosis was measured using the terminal dUTP nick-end labeling (TUNEL) method. When subjected to simulated weightlessness, the cellular morphology of SGC-7901 cells was changed at 12, 24, 48, and 72 h, cell conversion from the G1 to S phase was blocked, proliferation was inhibited at 48 and 72 h, and the apoptosis index was increased at 72 h. The same changes were observed for HFE-145 cells at 12 h when subjected to simulated weightlessness, but no significant changes were found afterward compared with controls. SGC-7901 cells change their cellular morphology and biological characteristics during clinostat-simulated weightlessness at 72 h, but HFE-145 cells only change at 12 h and adapt to simulated weightlessness after that point.

Preparation and identification of specific and high-affinity monoclonal antibodies against morphine.

A C6-hemisuccinate derivative of morphine was prepared and conjugated to bovine serum albumin and ovalbumin. High titer antibody producing spleen cells were removed and fused with myeloma cells of SP2/0 origin. Using a conventional immunization protocol generated twenty-six stable murine monoclonal antibodies (MAbs) producing cell lines to morphine. The donor mouse produced antiserum with a high titer of 1/640,000. Twelve MAbs were selected for further characterization since they showed high sensitivities (53 pg/well to inhibit 50% of the tracer) in improved group-selective immunoassay (IGSI). The assay, which maintains high sensitivity, high precision, and a wide range of optical density (OD) values, was developed using the conjugate M-6-S-OVA to screen and characterize the anti-morphine MAbs. After four successive limiting dilutions, antibodies produced by 12 clones had high affinities ranging from 10(9) to 10(10) M(-1). These clones were found to be of Ig(G) class and IgM class with kappa and lambda light chain. Subclass determination showed that the clones produced IgG1, IgG2a, IgG3, and IgM types of antibody. One clone (2F8B11F2A12) was used to establish the calibration curve with a sensitivity of 400 pg/mL covering up to 25.6 ng/mL in urine.