Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
George H.W. Bush to Remain in Hospital
Former U.S. President George H.W. Bush will remain in Houston Methodist Hospital "to continue regaining strength" after treatment for an infection that spread to his blood, a family spokesman said Monday.
Bush, 93, was admitted to the hospital on April 22, a day after the funeral of his wife, Barbara, the Associated Press reported.
Bush "is in great spirits and is looking forward to going home soon," according to family spokesman Jim McGrath.
The former president has a form of Parkinson's disease and a history of pneumonia and other infections, the AP reported.
Concern Over Clusters of Rare Eye Cancer in Two States
Two clusters of an extremely rare eye cancer in Alabama and North Carolina are being investigated by researchers.
Ocular melanoma typically occurs in just six of every one million people, but has been diagnosed in a group of 18 patients in Huntersville, North Carolina and in another group of patients in Auburn, Alabama, some of whom attended Auburn University together, CBS News reported.
One of the patients is Ashley McCrary, who went to Auburn University. She started a Facebook page and says 36 people have responded to say they also attended Auburn University and have been diagnosed with ocular melanoma.
"We believe that when we're looking at what's going on in Huntersville, North Carolina, and what's going on here, there is something that potentially links us together," she told CBS News.
The patients are being studied by oncologist Dr. Marlana Orloff, Sidney Kimmel Cancer Center at Thomas Jefferson University in Philadelphia, and colleagues.
"Most people don't know anyone with this disease," Orloff told CBS News. "We said, 'OK, these girls were in this location, they were all definitively diagnosed with this very rare cancer -- what's going on?'"
It "would be premature to determine that a cancer cluster exists in the area," the Alabama Department of Health said.
NFL Denies Player's Request for Medical Marijuana Use Exemption
NFL running back Mike James' career may be in jeopardy due to his use of medical marijuana, because the league considers it a banned substance.
After an ankle injury in 2013, James was prescribed opioid painkillers and soon developed a dependency on the drugs. To tackle the dependency, he turned to medical marijuana for his pain, and it proved effective.
"I never had something where I could be coherent and still have pain relief," James said in a CNN documentary that aired Sunday night.
However, the NFL and NFL Players Association prohibit active players from using marijuana unless they have a therapeutic use exemption indicating that they require the substance to treat a diagnosed medical problem.
Last month, James became the first player to file for an exemption specifically for cannabis, but he found out last Thursday that the NFL had denied the application, CNN reported.
James, who is a free agent after being released by the Detroit Lions, said he won't give up.
"My career is at great risk," he told CNN.
Caterpillar Invasion in London Puts People at Risk of Deadly Allergic Reactions
Caterpillars that can cause potentially deadly allergic reactions have invaded parts of London, England, officials warn.
Caterpillars of the oak processionary moth started emerging from eggs in mid-April, the Forestry Commission said, The New York Times reported.
Long white hairs released by the caterpillars can cause allergic reactions in people who are allergic. Reactions can range from skin and eye irritation, to difficulty breathing and even anaphylactic shock.
"At best, you can get contact dermatitis. At worst, you can die," Jason Dombroskie, manager of the Cornell University Insect Collection and coordinator of the Insect Diagnostic Lab in Ithaca, N.Y. told The Times.
"You can go into anaphylactic shock and have your airways close up. The airborne hairs set up a whole different ballgame," he said.
The Forestry Commission is treating trees in affected areas with biopesticides, which use viruses or bacteria that target the caterpillars. The treatment of trees at more than 600 sites is expected to continue until late May or early June, The Times reported.
"We advise people not to pick up the caterpillar or pick up the nest," a spokeswoman for Britain's Department for Environment, Food and Rural Affairs said. She added that there have been no reports of serious illness due to contact with the caterpillars.