High-speed atomic force microscopy combined with inverted optical microscopy for studying cellular events.

A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have been a long-standing wish. Here we describe the implementation of high-speed AFM coupled with an optical fluorescence microscope. This was accomplished by developing a tip-scanning system, instead of a sample-scanning system, which operates on an inverted optical microscope. This novel device enabled the acquisition of high-speed AFM images of morphological changes in individual cells. Using this instrument, we conducted structural studies of living HeLa and 3T3 fibroblast cell surfaces. The improved time resolution allowed us to image dynamic cellular events

Effect of pollen exposure on serum IgE and IgG antibody responses in Japanese cedar pollinosis patients

We examined the IgE and IgG antibody responses in Japanese cedar pollinosis patients before and after the pollination season for 2 years. The sera from 90 patients in 1990 and 87 in 1991, living in five regions in the Tokyo area, were obtained before and after the pollination season. In all patients, changes (increase then decrease) in specific IgE levels were detected after natural pollen exposure. Total IgE and specific IgG concentrations also changed. However, the degree of change in specific IgE was greater than those in total IgE and specific IgG. Then, the geometric means of specific and total IgE levels were compared among the five regions. These levels were found to be highest in the region where the pollen count was the highest. These findings suggest that IgE antibody production is more stimulated after natural pollen exposure compared to IgG antibody production, and is dependent on the amount of allergens