Abstract: The present invention provides a preventive or therapeutic drug for a myeloma tumor and osteoclastic bone loss associating therewith, the drug containing as an active ingredient an osteopontin-production regulator or inhibitor; a screening method for a preventive or therapeutic drug for a myeloma tumor, characterized by determining osteopontin production regulatory or inhibitory effect; as well as a diagnostic kit for a myeloma tumor, characterized by including a reagent for measuring blood osteopontin level, and a diagnostic method.

Abstract: The present invention provides a preventive or therapeutic drug for a myeloma tumor and osteoclastic bone loss associating therewith, the drug containing as an active ingredient an osteopontin-production regulator or inhibitor; a screening method for a preventive or therapeutic drug for a myeloma tumor, characterized by determining osteopontin production regulatory or inhibitory effect; as well as a diagnostic kit for a myeloma tumor, characterized by including a reagent for measuring blood osteopontin level, and a diagnostic method.

Abstract: An anti-osteopontin antibody which inhibits the binding of an integrin recognizing RGD sequence to osteopontin or its fragment, and which inhibits the binding of an integrin recognizing SVVYGLR sequence or sequence equivalent thereto to osteopontin or its fragment. This antibody is useful in remedies for autoimmune diseases, remedies for rheumatism and remedies for rheumatoid arthritis. Also, a method of treating autoimmune disease, rheumatism or rheumatoid arthritis is provided. This antibody is useful in diagnostics and a diagnostic method for rheumatism too.

Abstract: The present invention provides a preventive or therapeutic drug for a myeloma tumor and osteoclastic bone loss associating therewith, the drug containing as an active ingredient an osteopontin-production regulator or inhibitor; a screening method for a preventive or therapeutic drug for a myeloma tumor, characterized by determining osteopontin production regulatory or inhibitory effect; as well as a diagnostic kit for a myeloma tumor, characterized by including a reagent for measuring blood osteopontin level, and a diagnostic method.

Abstract: This invention relates to a method of inhibiting OPN production, which comprises administering an effective amount of a pyridazine derivative represented by the following formula (I) or a salt thereof: wherein: R1 means a substituted or unsubstituted phenyl or pyridyl group; R2 means a substituted phenyl group; R3 means a hydrogen atom or a substituted or unsubstituted phenyl or pyridyl group; A means a single bond, a C1-6 linear or branched alkylene group, or a C2-9 linear or branched alkenylene group; and X means an oxygen atom or a sulfur atom.

Abstract: The present invention provides a preventive or therapeutic drug for a myeloma tumor and osteoclastic bone loss associating therewith, the drug containing as an active ingredient an osteopontin-production regulator or inhibitor; a screening method for a preventive or therapeutic drug for a myeloma tumor, characterized by determining osteopontin production regulatory or inhibitory effect; as well as a diagnostic kit for a myeloma tumor, characterized by including a reagent for measuring blood osteopontin level, and a diagnostic method.

Abstract: An anti-osteopontin antibody which inhibits the binding of an integrin recognizing RGD sequence to osteopontin or its fragment, and which inhibits the binding of an integrin recognizing SVVYGLR sequence or sequence equivalent thereto to osteopontin or its fragment. This antibody is useful in remedies for autoimmune diseases, remedies for rheumatism and remedies for rheumatoid arthritis. Also, a method of treating autoimmune disease, rheumatism or rheumatoid arthritis is provided. This antibody is useful in diagnostics and a diagnostic method for rheumatism too.