One of the world's largest charities, Bethesda's Howard Hughes Medical Institute, last week announced the first round of winners in its 10-year, $500 million giveaway to support medical and biological sciences.

Purnell W. Choppin, the institute's chairman, said the objective of the program is to "support the best students in the biological sciences while they obtain the graduate education and training needed for a research career" and strengthen undergraduate biological science programs throughout the country.

Special emphasis will also be placed on increasing the participation of minority students in biomedical research.

The program dramatically expands the institute's activities, which for years have been limited to funding special laboratory units at teaching hospitals. Created in 1953 by reclusive billionaire Howard Hughes as the sole shareholder of Hughes Aircraft, the institute was until recently defined by the tax laws as a medical research organization and not permitted to give grants and scholarships for independent researchers.

The institute sold Hughes Aircraft in 1985 to General MotorsCorp., and struck a deal with the Internal Revenue Service in March of this year that made it possible to use the $5 billion it received from the sale to support a much wider variety of scientific activities.

The new program will create a $30 million fund to strengthen education and research in the sciences at liberal arts colleges, with special provisions for historically black institutions. The grants range from $500,000 to $2 million and will be awarded on the basis of a special competition.

Another $5 million has been granted to the National Academy of Science to study public policy issues in researc