The Los Angeles Business Journal’s index of largest local public companies closed up for the first week of the year, as an encouraging national jobs report offset continuing concerns about the European debt crisis.

The weighted LABJ Stock Index closed up 1.69 percent to 122.58 for the week ended Jan. 6. Gainers outpaced decliners 96 to 66, with 11 companies unchanged. In comparison, the S&P 500 rose 1.35 percent to 1,277.81, and the Dow Jones industrial average closed up 0.75 percent to 12,359.92.

The top local gainer was Arrowhead Research Corp., which jumped 25 percent to $5.29. The Pasadena medical nanotechnology company said the U.S. Food and Drug Administration had accepted its application to begin clinical trials on a new anti-obesity drug.

Virco Manufacturing Corp. had another strong week. The Torrance maker of business and school furniture, which has been struggling in the uncertain economy, rose another 20 percent to close at $1.79 after gaining 19 percent the previous week after announcing a new line of credit.

Live Nation Entertainment Inc. rose 15 percent to $9.66 despite some bad news for its ticketing subsidiary. The jump was driven by a big slate of rock tours scheduled for this year. One example: Madonna, a Live Nation artist, will appear at the Super Bowl and tour in support of a new album.

Reliance Steel & Aluminum Co. rose 9 percent to $52.86. Shares of the Los Angeles operator of metals service centers rose on news that crude steel production rose in the fourth quarter.

Among the decliners was Jakks Pacific Inc., which fell 6.7 percent to $13.36. Shares of the Malibu toymaker continued to decline after the previous week’s warning about mixed holiday sales.