Abstract: A simple and efficient method of preparing active recombinant human neutrophil chemotactic factor. The human neutrophil chemotactic factor (NCF) is solubilized from a transformant cell homogenate using urea or guanidine hydrochloride. The polypeptide is further purified from the solution using conventional protocols such as CM-Sepharose CL-6B, HW-55 column, etc.. By using this method, large amounts of active human NCF can be recovered and purified.

Abstract: DNAs encoding polypeptides having interleukin 1, vectors inserted with said DNAs, hosts transformed with said recombinant vectors, polypeptides having interleukin 1 activity which are produced by cultivation of the transformed hosts, derivatives of the polypeptides, pharmaceutical composition containing said polypeptides or derivatives, their use as an antitumor or antiinfectious agent, and processes for the preparation thereof.

Abstract: In a flame-retardant rubber tire comprising an outer rubber body portion consisting essentially of a tread rubber layer, a sidewall rubber layer extending inward from each side edge of the tread rubber layer toward the vicinity of a bead portion in radial direction and a rubber chafer layer arranged in the vicinity of the bead portion, a flame-retardant rubber composition having an oxygen index of not less than 19.8 but not more than 27.5 is disposed so as to amount at least 20% by weight of the tread rubber layer. Such rubber tires are used in electric vehicles, automobiles, airplanes and the like and have excellent self-extinguishing property and flame-delaying property without damaging other rubber properties.

Abstract: A flame-retardant rubber composition has an oxygen index of 19.8-27.5 and comprises not more than 24% by weight of red phosphorus as a flame retardant based on the rubber composition and a nitrile group-containing elastomer as a flame-retardant polymer component as a part of rubber ingredients constituting the rubber composition. Such flame-retardant rubber compositions are very useful in applications such as industrial goods, tire and the like strongly requiring the fire preventing function.

Abstract: An expression vector in which a DNA encoding a human neutrophil chemotactic factor polypeptide is inserted, a transformant (a host cell transformed with the expression vector), and a process for production of the said polypeptide by using the said transformant.

Abstract: Novel polypeptides having a modified amino acid sequence of human interleukin 1.alpha. polypeptides in which a certain amino acid residue(s) in said amino acid sequence is(are) exchanged for other amino acid residue(s). Said polypeptides having no capacity of induction of production of prostaglandin E.sub.2 while maintaining other biological activities of human interleukin 1 such as activation of lymphocyte and being expected to be useful as a medicament.

Abstract: A human TNF polypeptide mutant having an amino acid sequence of modified human TNF polypeptide, a DNA having a base sequence encoding the above human TNF polypeptide mutant and a method of producing the above human TNF polypeptide mutant by culturing a host transformed with a vector having inserted therein the above DNA. The above human TNF polypeptide mutant is soluble and has antitumor activity.