A technique to study CELL MIGRATION in the INFLAMMATION process or during immune reactions. After an area on the skin is abraded, the movement of cells in the area is followed via microscopic observation of the exudate through a coverslip or tissue culture chamber placed over the area.

The innermost layer of the three meninges covering the brain and spinal cord. It is the fine vascular membrane that lies under the ARACHNOID and the DURA MATER.

Surgical construction of an opening or window in the pericardium. It is often called subxiphoid pericardial window technique.

Exudates are fluids, CELLS, or other cellular substances that are slowly discharged from BLOOD VESSELS usually from inflamed tissues. Transudates are fluids that pass through a membrane or squeeze through tissue or into the EXTRACELLULAR SPACE of TISSUES. Transudates are thin and watery and contain few cells or PROTEINS.