Abstract: A DNA encoding a cell surface polypeptide of Porphyromonas gingivalis, and a recombinant DNA being a DNA having integrated said DNA thereinto. The cell surface polypeptide of the periodontopathic organism useful for prophylaxis and diagnosis of periodontal diseases can be obtained in a large amount by a microorganism containing the recombinant DNA wherein the DNA was integrated.

Abstract: A DNA encoding a cell surface polypeptide of Porphyromonas gingivalis, and a recombinant DNA being a DNA having integrated the encoding DNA thereinto. The cell surface polypeptide of the periodontopathic organism useful for prophylaxis and diagnosis of periodontal diseases can be obtained in a large amount by a microorganism containing the recombinant DNA wherein the DNA was integrated.

Abstract: A water-soluble carboxypolysaccharide-magnetic iron oxide complex of small particle diameter composed of a water-soluble carboxypolysaccharide and a magnetic iron oxide having a core diameter ranging from about 2 to about 7 nm, wherein the total diameter ranges from about 10 to about 50 nm, the ratio of the total diameter to the core diameter is about 15 or less, and the T.sub.2 -relaxivity ranges from about 10 to about 150 (mM.sec).sup.-1. Said complex has low toxicity and small side effects and is useful in the fields of medical treatment, biology and engineering as an iron-supplementing agent, an X-ray contrast medium, an MRI contrast medium, a reagent for blood flow rate measurement, a carrier for drug administration, etc.

Abstract: An oxidized complex comprising a water-soluble carboxypolysaccharide and magnetic iron oxide, which is characterized by being obtained by oxidizing a complex comprising a water-soluble carboxypolysaccharide and magnetic iron oxide. Said oxidized complex has very low toxicity, is very stable, exhibits little or no blood pressure-reducing action and has low platelets-aggregating action when administered directly into the blood vessels of animals, and is useful in medical fields such as contrast medium for magnetic resonance imaging, exothermic medium for hyperthermia and the like.

Abstract: A composition containing magnetic metal oxide ultrafine particles, which comprises an aqueous sol of a complex of the magnetic metal oxide ultrafine particles with a polysaccharide, a polysaccharide derivative and/or a protein; and an organic monocarboxylic acid. The composition is free of side effects such as platelet aggregation, is safe for use with living bodies, and, in the case of intravascular administration, has no harmful effects on living bodies, and is useful in fields such as medicine and diagnostic drugs.

Abstract: Novel mannobiose derivative represented by the general formula [I]: ##STR1## wherein groups of R.sub.1 to R.sub.5 each represents --OH, --OR.sub.6, --NHR.sub.6, (R.sub.6 represents an acyl group) or a group represented by the following formula (a), (b), (c), (d) or (e), provided that one of R.sub.1 to R.sub.5 represents --OR.sub.6 or --NHR.sub.6, one of the other 4 groups of R.sub.1 to R.sub.5 represents one of the groups represented by the formulae (a) to (e), and the remaining 3 groups of R.sub.1 to R.sub.5 represent --OH: ##STR2## wherein represents .alpha. or .beta. bond are provided by the invention.These compounds give liposomes a specific affinity for Kupffer cells of liver, and can be produced industrially.