A look inside Hollywood and the movies : HOLLYWOOD OBSERVER : They’re Down. They’re Up. Repeat Often.

The mega-success of Universal Pictures’ “Jurassic Park” and the box-office bonanza promised by TriStar Pictures’ romantic comedy “Sleepless in Seattle” help illustrate how the fortunes of studios and the reputations of the executives who run them can quickly flip-flop in ever-fickle Hollywood.

Only six months ago, TriStar Chairman Mike Medavoy was a marked man. By most accounts, he was soon to be looking for work.

Likewise, last year, MCA Motion Picture Group Chairman Tom Pollock, who heads Universal Pictures, was said to be hanging by his teeth.

Time proved the rumors wrong. The two studio chiefs had merely been subjected to ordinary industry gossip fueled by the performances of their movie operations at the time.

Back to the present. Now, even though conventional wisdom dictates that no single hit or miss will make or break a studio or studio chief, the box-office windfalls of their respective summer movies, Steven Spielberg’s “Jurassic Park” and Nora Ephron’s far-from-sleepy “Seattle,” have put Pollock and Medavoy back on top--if only momentarily.

First, let’s take the case of Medavoy. Not so long ago, Hollywood was so convinced that Medavoy was going to be ousted and was consequently setting his sights (as a Friend of Bill) on Washington, that a Jan. 10 New York Times article about executives who wear jeans mistakenly said he had been “relieved of his duties as chairman of TriStar Pictures.”

The speculation had been fueled by criticism that he had been sluggish in making crucial decisions like greenlighting movies (he only put four into production last year) and releasing Woody Allen’s box-office dud “Husbands and Wives.” Mike Medavoy was the industry’s favorite whipping boy.

Meanwhile, his counterpart at TriStar’s sister studio, Columbia Pictures, Mark Canton, was gobbling up as much good press as humanly possible. Canton, who took over the head job at Columbia in the fall of 1991, was being touted around the Columbia lot as the Wunderkind brought over from Warner Bros. to deliver “Batman”-level hits.

But with the recent disappointment of his self-promoted big-star, big budget, big-deal film, “Last Action Hero,” Canton’s now on the hot seat. At the moment, he’s the guy in town everybody loves to hate.

And guess who’s a hero in Hollywood now? Not only does Medavoy appear to have a big hit on his hands with “Sleepless” (thanks in great part to TriStar President Marc Platt and production president Stacy Lasalley’s team, who put the picture together with Ephron), the studio’s early summer release, “Cliffhanger,” starring Sylvester Stallone, doesn’t look so bad after all. As a matter of fact, with a cumulative box-office take of more than $65 million (and still growing), many industry observers believe the picture will out-gross--at least domestically--”Action Hero.”

On to the case of Pollock. Rumors about him began spreading early last year as Universal was suffering through a prolonged dry spell at the box office. When the talk died down for a while, it took on new life with the disappointing release of the expensive Tom Cruise saga “Far and Away.”

So, what do Medavoy and Pollock think now that their time in Hollywood gossip hell seems to have ended--at least for the moment? Both Medavoy and Pollock claim they take it all in stride, though they can’t deny that the stories and industry gossip didn’t sting like hell.

Why the charitable attitude from two guys who were supposed to be out on the street? They both know that Hollywood is a town that loves to gossip.

Climbing on his press-bashing horse, Pollock laments: “People in Hollywood, including journalists, spend too much time gossiping.” And, despite the huge success of “Jurassic” (expected to hit $200 million this weekend), he says, “the success or failure of any studio does not depend on any one film.”

Medavoy, who over his 19-year industry career has been involved with 285 movies, concurs: “I have no illusions” that any one picture drives the success or failure of a studio or an executive. “I’ve been up before, in the middle and down . . . I’m happy that Tom Pollock and I are doing well now and I’m sure that Mark Canton, who’s under siege now, will also continue to do well.”