Precision Therapeutics Inc., of Minneapolis, said CEO and director Carl Schwartz made an additional investment of $1 million, effective Jan. 8. Of that investment, $950,000 was a loan under an amended and restated promissory note, which now covers advances of $1.3 million, including a previous loan Schwartz made in November. He also purchased 78,125 shares of the company's common stock in a private investment for $50,000, representing a price of 64 cents per share.