Abstract: A thermal transfer recording sheet comprising a base film, a heat transferable ink layer formed on one side of the base film and a heat resistant lubricating layer formed on the other side of the base film, wherein said heat resistant lubricating layer comprises round particles, fine particles having a particle size smaller than that of the round particles and a heat resistant binder resin, as the main components, and the round particles are projecting from the standard surface of the heat resistant lubricating layer.

Abstract: A substituted aldosterone of the formula: ##STR1## wherein either one of R.sup.1 and R.sup.2 is hydrogen and the other is --S(CH.sub.2).sub.m COR.sup.3 or --OCO(CH.sub.2).sub.n COR.sup.3, provided that when R.sup.1 is hydrogen, R.sup.2 is --S(CH.sub.2).sub.m COR.sup.3 or --OCO(CH.sub.2).sub.n COR.sup.3 and when R.sup.2 is hydrogen, R.sup.1 is --S(CH.sub.2).sub.m COR.sup.3 ; m being an integer from 1 to 3, n being an integer from 1 to 5 and R.sup.3 being hydroxyl, lower alkoxy or a residue of tyramine, tyrosine lower alkyl ester, histamine, histidine, 7-aminoheptanoyltyrosine lower alkyl ester or .beta.-D-galactosidase as optionally iodinated, or its (18-20)-acetal 20,21-ketonide, which is useful as the reagent in determination of aldosterones by radioimmunoassay or enzyme immunoassay.

Abstract: A substituted aldosterone of the formula: ##STR1## wherein either one of R.sup.1 and R.sup.2 is hydrogen and the other is --S(CH.sub.2).sub.m COR.sup.3 or --OCO(CH.sub.2).sub.n COR.sup.3, provided that when R.sup.1 is hydrogen, R.sup.2 is --S(CH.sub.2).sub.m COR.sup.3 or --OCO(CH.sub.2).sub.n COR.sup.3 and when R.sup.2 is hydrogen, R.sup.1 is --S(CH.sub.2).sub.m COR.sup.3 ; m being an integer from 1 to 3, n being an integer from 1 to 5 and R.sup.3 being hydroxyl, lower alkoxy or a residue of tyramine, tyrosine lower alkyl ester, histamine, histidine, 7-aminoheptanoyltyrosine lower alkyl ester or .beta.-D-galactosidase as optionally iodinated, or its (18-20)-acetal 20,21-ketonide, which is useful as the reagent in determination of aldosterones by radioimmunoassay or enzyme immunoassay.

Abstract: The disclosed peptide derivative of the formula:Y--Tyr--Gly--RWherein, Y represents a hydrogen atom or an amino protecting group, Tyr represents a tyrosine residue wherein at least one of the hydrogen atoms on the phenyl ring may be substituted by a radioactive iodine, Gly represents a glycine residue, and R represents a peptide residue corresponding to an amino acid sequence which includes at least positions 7 through 21 of human proinsulin C-peptide proves to be useful for determining C-peptide level in human serum.