31.   But as with most of its own in-house projects, those compounds are several years away from human clinical studies.

32.   But Lee said in an interview that clinical studies on humans were now needed to determine whether there is benefit in lowering homocysteine levels.

33.   But on Tuesday, the first published clinical study of leptin finds that the substance is not the weight loss panacea that obesity researchers had hoped for.

34.   But medical experts at a workshop held in a hotel in Gaithersburg said the usual languid period of waiting to start a clinical study would not suffice.

35.   But Tuesday, the first published clinical study of leptin finds that the substance is not the weight loss panacea that obesity researchers had hoped for.

36.   But unlike the other companies, Rausch said, Biopure had already developed the test to evaluate the efficacy of its products in clinical studies.

37.   But until recently, no clinical studies taking into account the placebo effects have established that they actually work.

38.   But, he added, clinical studies had not confirmed his findings.

39.   Clinical studies found that the spray, marketed under the name Miacalcin, increased spinal bone mineral density in women more than five years after menopause.

40.   Clinical studies have fueled this rise, even though doctors say they are often unable to explain why some kinds of alternate treatments seem to work.