(FORTUNE Magazine) – FIRST WORLD CHEESE INC. The $14-billion-a-year cheese industry has been taking it on the chin lately from fitness-conscious consumers, not to mention the Surgeon General. That's what food consultant Carl Wolf was betting on when he founded First World Cheese in 1983 with just two other employees. Now traded over the counter, First World sells cheeses made with skim milk that are up to 50% lower in sodium, fat, and cholesterol than traditional cheeses made entirely from whole milk. Such ''nutritional'' cheeses represent a $400 million market slice that is growing about 40% per year. First World is expanding its line by adding such varieties as colby, Monterey Jack, and mozzarella and introducing cholesterol-free imitation cheeses made with soybean oil. Additional growth will come from a Utah plant that has a profitable sideline packaging cheeses for other makers and from a commodity trading business. Analysts estimate sales could more than double to $75 million next year, and earnings may reach 65 cents a share, up from 19 cents in 1987.

OCTEL COMMUNICATIONS CORP. Can we talk? This little-known Milpitas, California, company is catching up with such better-known competitors as IBM's Rolm subsidiary in the fast- growing business of computerized voice message systems. They answer and route incoming calls and allow employees to communicate with each other via electronic voice ''mailboxes.'' Octel's customers include Hewlett-Packard, General Electric, and BellSouth, which used Octel systems at the Democratic and Republican conventions. Octel even signed up a giant rival: AT&T needed a system fast and was still working out bugs in its own. Last year Octel's sales grew 150% to $48 million, and earnings zoomed 376% to just under $7 million. The company went public in February at $7 a share, and the over-the-counter stock recently traded at around $16. Analyst Steven Levy of Hambrecht & Quist thinks Octel could reach $85 million in sales and $11 million in profits in the fiscal year ending next June.

ISCO INC. With water polluters now Public Enemy No. 1, corporations and law enforcement officials are turning to Isco, the world's largest maker of waste-water test equipment, to evaluate surface water and waste discharges. Founded in landlocked Lincoln, Nebraska, as a maker of biochemical and medical instruments for research, Isco added its water test division 19 years ago. Analyst Edwin Lewis of First Kansas City Securities sees profits rising 25% to $5.5 million on sales of $35.5 million in the fiscal year ending next July. He expects the stock, which recently traded over the counter at $15, to reach $20 within a year.

FOREST LABORATORIES INC. This New York pharmaceutical company, traded on the American Stock Exchange, has asked the FDA to approve human testing for a new drug that treats Alzheimer's disease. Forest is already scheduled to begin tests on humans in Britain in a month or so. Analyst Jeffrey Berg of Nashville-based J.C. Bradford & Co. says annual sales of an Alzheimer's treatment could reach $250 million to $500 million worldwide. The only Alzheimer's drug now in human testing, Warner-Lambert's THA, causes liver problems in high doses. Although Forest's drug appears to have no dangerous side effects, President Howard Solomon has not revealed the active ingredient. Whatever happens to the Alzheimer's drug, analyst Berg predicts Forest's income will rise 26% next year to $21 million on sales of $106 million.