Shares of medical conglomerate Johnson & Johnson (JNJ) are declining after JPMorgan analyst Michael Weinstein downgraded the stock to Neutral from Overweight in a note to clients earlier today. CATALYST: Weinstein lowered his rating on the company because he believes that, after appreciating 30%, J&J's stock more than reflects the improvement in the company's fundamentals.The company now trades 8% above the value of its assets and 16% above the average value of large pharmaceutical companies, the analyst contended. Moreover, the company is likely to report lower than expected first quarter revenue due to 1-2 fewer business days during the quarter, and it will probably reduce its 2013 earnings per share guidance as a result of currency factors, the analyst believes. Finally, J&J's medical device and consumer units are still struggling, and the company is facing product liability battles, added Weinstein, who raised his target on the shares to $83 from $77. OTHERS TO WATCH: The analyst recommended that investors consider buying shares of medical device makers C.R. Bard (BCR) and St. Jude Medical (STJ). Bard's growth should accelerate in 2014-2016, while St. Jude should report good news about its troubled Durata defibrillator leads in coming months, the analyst wrote. TODAY'S PRICE ACTION: In early trading, Johnson & Johnson fell $1.40, or 1.7%, to $80.65.St. Jude was little changed at $41.80, while C.R. Bard was little changed at $100.