Abstract: The present invention provides an enhancer DNA segment, a gene fragment having (a) the enhancer DNA segment and (b) a structural gene such as human D, V and J gene, and a promoter. A hybrid DNA (1) having a phage DNA fragment from Charon 4A phage vector and human DNA fragments, a Charon 4A phage containing the hybrid DNA (1), a hybrid DNA (2) having a PBR322 fragment and human DNA fragment, a transformant of E. coli C600 strain transformed with the hybrid DNA (2), plasmid pSV2-H1G1 obtained by inserting a human DNA fragment into a vector pSV-2gpt, a transformant of E. coli MC 1000 strain transformed with the plasmid pSV2-H1G1 and a transformant of mouse myeloma cells J558L or NS-1 transformed with the plasmid pSV2-H1G1 are also provided.

Abstract: A mouse-human chimaeric immunoglobulin heavy chain comprising (a) the amino acid sequence of a mouse immunoglobulin heavy chain variable region and (b) the amino acid sequence of a human immunoglobulin heavy chain constant region and reacting specifically with human common acute lympohocytic leukemia antigen and a chimaeric DNA fragment which encodes the amino acid sequence of the above mouse-human chimaeric immunoglobulin heavy chain.

Abstract: A DNA sequence comprising a polynucleotide segment consisting of a DNA sequence (A) shown below and a DNA sequence complementary thereto: ##STR1## wherein A represents deoxyadenosine-5'-phosphate, C represents deoxycytidine-5'-phosphate, G represents deoxyguanosine-5'-phosphate, and T represents deoxythymidine-5'-phosphate.The DNA sequence provided by this invention is derived from a rearranged immunoglobulin heavy chain variable (V.sub.H) region gene taken from the mouse hybridoma NL-1 cells which produce an antibody capable of commonly recognizing surface antigens of various human acute lyphocytic leukemia cells. Accordingly, if, for example, it is combined with a heavy chain constant (C.sub.H) region gene, a heavy chain can be produced which can recognize commonly various human acute lymphocytic leukemia cells in combination with a proper light chain. This would serve for the diagnosis and treatment of human acute lymphocytic leukemia.

Abstract: A Stirling engine which has an expansion cylinder and a compression cylinder with an expansion piston and a compression piston, respectively, that have a fixed phase difference between them, where the expansion cylinder and the compression cylinder are connected through a heater, a regenerator, and a cooler, a fixed amount of working fluid is sealed in the expansion cylinder and a compression cylinder, and the engine is driven by heating or cooling the working fluid with the heater or the cooler, and in the above Stirling engine, the heater for heating the working fluid includes a combustion chamber attached to the expansion cylinder, a burner for jetting a combustible substance into the combustion chamber, a plurality of heat exchanger pipes for forming a plurality of passages for the working fluid to connect through between the expansion cylinder and the regenerator by turning back on themselves, in order to heat the working fluid with the high temperature gas from the burner, and a cylinder head for instal

Abstract: A heparin derivative in which at least 0.5% of the entire hydroxyl groups of heparin are in the form of an ester of the following formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 each represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; a method for producing aforesaid heparin derivative which comprises reacting heparin with a halide or anhydride of an unsaturated carboxylic acid of the formula ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 are the same as defined above; and a method for imparting antithrombotic activity to a biomedical material, which comprises treating that surface of the biomedical material which makes contact with the blood with actinic light in the presence of aforesaid heparin derivative.