Shares in artificial joint specialist Smith & Nephew have pressured the healthcare equipment and services sector higher after widespread reports that it rejected a bid approach from giant US rival Johnson & Johnson just before Christmas. J&J is said to have offered about 750p per share, valuing the knee joint maker at almost £6.7bn. The shares closed on Friday at 650p. Smith & Nephew has yet to make a comment on the reports, but may be forced to make an official statement if the share price takes off. J&J had its approach rebuffed, the reports said, on the grounds it was too low, but is said to be considering whether to come back with a higher offer.Construction and materials is heading lower with infrastructure group Balfour Beatty and construction and regeneration firm Morgan Sindall seeing profits taken.Shares in the two group are falling despite a joint venture, in which the two groups each have a 30% interest, has won the £235m Whitechapel and Liverpool Street Station tunnels contract, which forms part of the huge Crossrail project.Top performing sectors so far todayHealth Care Equipment & Services 4,064.61 +10.72%Oil Equipment, Services & Distribution 25,650.74 +1.55%Mobile Telecommunications 4,035.61 +0.85%Technology Hardware & Equipment 652.86 +0.73%Fixed Line Telecommunications 2,390.24 +0.57%Bottom performing sectors so far todayForestry & Paper 5,455.69 -2.31%Construction & Materials 4,050.61 -1.55%Industrial Metals & Mining 8,306.06 -1.46%Mining 26,993.74 -1.16%Real Estate Investment Trusts 1,999.90 -1.14%