A sensor system for diagnosing dental conditions includes a sensor unit which is in contact with an oral fluid such as saliva or gas, and which is operative to provide detectable signals indicative of at least two of hydrogen ion concentration, hydroxyl ion concentration, calcium, phosphate, sulfur, sulfur containing compounds, nitrogen containing compounds, microbial metabolites, and microbes. A time interval is selected at which position command signals will be received. A multicast group coordinator which manages the multicast group is set among the nodes forming the multicast group. They are generally suitable for treating diseases which are caused by, or associated with, an undesirable degree of leukocyte adhesion andor leukocyte migration or in which cell-cell or cell-matrix interactions, which are based on the interactions of VLA-4 receptors with their ligands, play a role. A group V element component in a III-V compound semiconductor single crystal or a group VI element component in the II-VI compound semiconductor single crystal is reduced less than a composition ratio expressed by a chemical formula of a corresponding compound semiconductor single crystal in a pattern-shaped portion. A second layer comprising a top sheet of material and a bottom sheet of material are also welded together so as to form a plurality of chambers in fluid communication with each other.