Abstract: A method for culture of hair follicular dermal sheath cells or precursor cells thereof which are potent cellular materials for such as hair regeneration by cell transplantation is provided. That is, by performing culture in an animal cell culture medium supplemented with platelet-derived growth factor AA (PDGF-AA) and fibroblast growth factor 2 (FGF2), hair follicular dermal sheath cells are proliferated while sustaining their function, or hair follicular dermal sheath precursor cells are differentiated into dermal sheath cells and proliferated.

Abstract: Human adult hepatocytes are transplanted into an immunodeficient hepatopathy mouse and then human growth hormone is administered to the mouse to thereby elevate twice or more the replacement ratio by the human adult hepatocytes having been transplanted. Further, human growth hormone is administered to an immunodeficient hepatopathy mouse carrying human young hepatocytes transplanted thereinto so as to improve fatty liver of the mouse in which about 70% or more of the hepatocytes have been replaced by the human hepatocytes.

Abstract: As novel means for causing any recombinant protein produced by the silkworm middle silk gland to be secreted in cocoons and easily extracting the recombinant protein from the cocoons without modification of the conformation of the protein, there is provided a polynucleotide that in an expression cassette for expression of a recombinant protein by the silkworm middle silk gland, is functionally linked to a recombinant protein structure gene, which polynucleotide is one composed of a polynucleotide constructing the promoter regions of sericin 1 or sericin 2 gene and, functionally linked thereto, a polynucleotide constructing the homologous regions of baculovirus.