Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

Petition to Reclassify Marijuana Rejected by Appeals Court

A petition to reclassify marijuana from its current status in the United States as a dangerous drug with no accepted medical use was rejected Tuesday by a federal appeals court.

The petition was submitted by several individuals and three medical marijuana groups, the Associated Pressreported. In 2011, a petition to change marijuana's classification was rejected by the U.S. Drug Enforcement Administration.

Tuesday's appeals court ruling came a few months after Colorado and Washington state legalized marijuana for recreational use.

In his majority opinion Tuesday, Judge Harry Edwards noted that the issue wasn't whether marijuana may have some medical benefits, but rather whether the DEA's decision to reject the petition was "arbitrary and capricious," the APreported.

The appeals court concluded that this was not the case.


Drug Co. Analysis Predicted High Failure Rate for Hip Implant

An internal Johnson & Johnson analysis revealed that the company believed that an all-metal hip implant would fail within five years in nearly 40 percent of patients who received the device.

The company recalled the Articular Surface Replacement in mid-2010. The analysis was conducted in 2011 but never released, according to newly disclosed court documents, The New York Timesreported.

At the same time it was conducting the analysis, Johnson & Johnson was publicly playing down a British implant registry's similar findings about the hip implant's early failure rate.

The analysis also indicates that the device is likely to fail prematurely over the next few years in thousands more patients in addition to those who have already undergone surgery to replace it, the Timesreported.

The analysis is among hundreds of internal Johnson & Johnson documents expected to be made public as the first of more than 10,000 lawsuits over the all-metal hip implant prepares to go to trail this week.


Bill and Melinda Gates Get Public Welfare Medal

Bill and Melinda Gates have been presented with the 2013 Public Welfare Medal for their efforts to improve the lives of millions of people around the world, the U.S. National Academy of Sciences said.

The award is the academy's most prestigious award and is presented each year to honor recipients' use of science for the public good. This year's winners are co-chairs and trustees of the Bill & Melinda Gates Foundation, which works to help all people lead, healthy productive lives, according to the academy.

Since 1994, the foundation has provided $25 billion in grants and works in more than 100 countries.

"Bill and Melinda Gates have changed the trajectory of international public health," Susan Wessler, home secretary of the National Academy of Sciences and chair of the selection committee for the award, said in an academy news release.

"Their science-driven approach to tackling so many seemingly intractable problems -- from reducing the spread of deadly diseases to curbing hunger and poverty -- has benefited the world's neediest people," Wessler said.


Most U.S. Research Chimps To Be Retired

All but 50 of hundreds of chimpanzees used for U.S. government-funded research should be retired from labs and sent to a sanctuary, federal scientists said.

A U.S. National Institutes of Health committee also called for major cuts in grants to study chimps in laboratories and said there should be no return to breeding chimps for research, the Associated Pressreported.

The recommendations, which were approved Tuesday by the NIH Council of Councils Working Group, were welcomed by animal-rights activists.

A statement released by People for the Ethical Treatment of Animals said: "At last, our federal government understands: A chimpanzee should no more live in a laboratory than a human should live in a phone booth."

The freed chimps will be sent to the Chimp Haven sanctuary in Louisiana. Sanctuary officials said nine chimps arrived Tuesday, seven more are expected Thursday, and another 95 will arrive over coming months, the APreported.