A prominent neuroscientist at USC is on leave nearly a year after allegations of research misconduct cast doubt on his published work and derailed trials for an experimental stroke treatment.

USC Keck School of Medicine Dean Carolyn Meltzer sent an email to faculty in the department of physiology and neuroscience on Oct. 22, disclosing that professor Berislav V. Zlokovic was on leave “for an indefinite period.”

In the email, Meltzer said that professor Steve Kay would serve as acting director of both the Zilkha Neurogenetic Institute and the department of physiology and neuroscience, positions that Zlokovic formerly held.

A spokesperson confirmed Zlokovic’s leave and Kay’s acting appointments on Monday but declined to provide further details, citing confidentiality surrounding personnel matters. Zlokovic didn’t immediately respond to requests for comment Monday.

Late last year, a group of whistleblowers submitted a report to the National Institutes of Health questioning the integrity of Zlokovic’s research and the safety of an experimental stroke treatment developed by ZZ Biotech, the company he co-founded.

The report identified allegedly doctored images and data in 35 research papers in which Zlokovic was the sole common author. It also questioned findings in the Phase II clinical trials of 3K3A-APC, a drug intended to reduce post-stroke brain bleeds.

The whistleblowers’ findings and news of Zlokovic’s leave were first reported in the journal Science.

On Sept. 26, Houston-based ZZ Biotech officially canceled 3K3A-APC’s clinical trial, according to a notice of withdrawal filed on the government’s database of clinical research studies.

“Any decisions on the future development pathway of 3K3A-APC in stroke will need to wait until the investigations of Dr. Zlokovic are complete,” ZZ Biotech Chief Executive Kent Pryor said Monday. Zlokovic no longer has any managerial or scientific affiliation with the company but remains a minority equity holder as co-founder, Pryor said.

NIH paused the trial in November 2023. It also launched an investigation into Zlokovic and instructed USC to return $1.9 million in funding already supplied for the study, Science reported.

A spokesperson for USC didn’t immediately respond to questions about the university’s obligations to return any federal money related to the study.

Zlokovic is a leading researcher on the blood-brain barrier, with particular interest in its role in stroke and dementia. After joining the USC faculty in 1989, he left and spent 11 years at the University of Rochester before returning to USC in 2011. He was appointed director of USC’s Zilkha Neurogenetic Institute the following year.

He retained his department chair and institute director titles as USC launched an investigation after the whistleblower report.

Since the allegations became public, three of Zlokovic’s hundreds of published research papers have been retracted. Eight more have been issued corrections or expressions of concern, a note journals append to articles when they believe there may be a problem with a paper but have not proved so.

Dr. Matthew Schrag, an assistant professor of neurology at Vanderbilt who co-authored the whistleblower report independently of his work at the university, previously told The Times that he and his colleagues did not find evidence of manipulated data in the drug trial. But given the degree of concern surrounding Zlokovic’s earlier work, he said, a clinical trial relying on his research to treat patients in life-threatening situations deserved further scrutiny.

“When you’re seeing a red flag or a trend in the clinical trial, I would tend to give that more weight in the setting of serious ethical concerns around the pre-clinical data,” Schrag said earlier this year. Schrag didn’t immediately respond to requests for comment Monday.

An 80-something patient came in for an annual visit recently and was worried that recent memory lapses might be symptoms of Alzheimer’s disease. This patient, like several others in my practice, has taken cognitive tests annually for more than a decade.

With each passing year, I see and hear the patient’s spiral of worry: Am I getting more forgetful? Perhaps it feels like “Where are my keys?” and “Where did I leave my wallet?” have become common refrains. These are simple memory lapses, an experience most people have throughout their lives, but they can be troubling as we get older. Are they signs of Alzheimer’s? Or signs of that other dreadful A-word … aging?

Year after year, for 10 years, in fact, this patient’s cognitive tests had come back normal. Until this year, when a blood test was positive for biomarkers for Alzheimer’s — triggering a further sense of panic. But here’s the problem: Science can’t yet tell us whether a positive test means the patient has an early stage of the disease. The only new data point was that this patient, so long dreading this day, had positive biomarkers showing increased risk for the disease. This person may not develop full-blown Alzheimer’s for five years or 20 years or ever. So did running that test have any benefit?

There is a sense of urgency in the medical community to classify a positive biomarker test as “Stage One Alzheimer’s Disease.” This is part of a larger desire to appear aggressive in fighting the disease, which for so long had no tests and no course of treatment.

I get that, and I understand why so many older patients fear Alzheimer’s, but I disagree with doctors whose response is to test early and often — and to diagnose Stage One Alzheimer’s based solely on biomarkers.

That categorization is potentially dangerous to patients, an unnecessary source of middle-of-the-night stress that can be deeply damaging to the very quality of life this person seeks to retain.

Such worries have become more widespread recently as the biomarker blood tests, marketed by companies like Quest and Labcorp, became commercially available so that patients could pay for them out of pocket. Previously, they were only used by clinicians in studies.

There’s an understandable impulse behind the medical community’s push to test lots of people. The more the disease is diagnosed, the more individuals will be identified for future treatments, and there is no doubt we need to improve recognition of early dementia, especially in medically underserved populations.

At the same time, pharmaceutical companies need more clinical trials — and also more patients — to develop new drugs to add to the array that already exists, such as Leqembi. In an aging nation with 7 million people already diagnosed with Alzheimer’s, we need these drugs, badly, but there’s no denying that profit lurks in the background as a motive here as well.

Although there are good reasons to test lots of people and gather a larger pool of patients who might have early stage Alzheimer’s, I think the cost to specific individuals can be just too great.

Candidates for clinical trials should not be identified based on positive blood tests from a clinical setting, but rather through carefully conducted research studies that have proper counseling and disclosure protocols.

More than 40% of individuals over 80 who take a biomarker test for Alzheimer’s will test positive. And it’s natural that many of them then will fixate on the worst-case scenarios and live their lives with a sense of worry and dread.

Patients who’ve tested positive come to me and bluntly state, “I have Alzheimer’s.” I see the scared look on their faces. Reaching this conclusion based on the biomarkers is like diagnosing cancer without doing a biopsy. The danger is real: Half of the patients who actually do have Alzheimer’s experience some sort of depression, and so do quite a few who think they have it — or worry they are sure to get it.

A positive blood biomarker test could also lead to significant mental and financial damage, with unnecessary and expensive procedures like an MRI, a PET scan or a spinal fluid test. Some people don’t like to hear this, but in many cases simple lifestyle changes like exercise, more rest and healthier eating could improve cognitive function. This is the recommendation I make to all my patients regardless of their Alzheimer’s risk.

For now, the biomarker test should be taken only if you are truly showing signs of Alzheimer’s disease. Here are some ways to tell: If a loved one is experiencing noticeable changes from their baseline mental abilities — such as losing track of time and place or struggling to find words — that can be a sign. Personality changes and new mood symptoms are other warning signs. Still, these symptoms should be distinguished from the slow and steady decline we will all experience.

If you do have symptoms, then yes, it could be time for biomarker tests, but only after thorough cognitive testing and a complete review of your medical history. That medical history could show other conditions such as sleep apnea that can influence memory. Lifestyle changes or treatments of those other conditions could resolve the troubling symptoms.

My stance on widespread testing will be different when doctors have more tools available to predict and treat Alzheimer’s and can offer constructive advice after a blood test comes back positive.

When someone has a cancerous tumor, surgeons remove it as soon as possible and start a treatment plan. When someone tests positive for the gene that indicates risk for a certain type of cancer, we monitor carefully.

A positive Alzheimer’s biomarker test, on the other hand, leads to no changes in clinical management when there are no cognitive symptoms. Prevention trials and improved predictive biomarkers for Alzheimer’s disease will change that, but we’re not there yet.

In the meantime, doctors’ oath to “do no harm” should mean we avoid overdiagnosing Alzheimer’s and fueling needless anxiety.

Keith Vossel is a professor of neurology at UCLA.

California air quality regulators late Friday approved tougher rules to encourage use of lower-carbon fuels, overriding objections that the action would lead to higher gasoline prices for motorists.

On an 12-to-2 vote, the California Air Resources Board approved amendments to the state’s Low Carbon Fuel Standard, or LCFS, which aims to shift California’s fuel dependence away from gasoline and toward lower-carbon fuels such as biodiesel, hydrogen and electricity.

The board members voting for the plan, some looking bleary-eyed by the end of the 12-hour meeting, said the new rules were needed to move the state closer to its goal of no longer burning fossil fuels.

“From a climate perspective, this is absolutely necessary,” said board member Hector De La Torre.

Dean Florez, a former Democratic state lawmaker, was one of two board members to vote no. He said one of his concerns was that the plan would make driving more expensive in a state that already has the second-highest pump prices in the nation after Hawaii.

“I’m just kind of wondering how we can in all good conscience, say that … somehow we’re not a cause of this,” Florez said.

Of the 14 voting members on CARB’s board, 12 were appointed by Gov. Gavin Newsom and confirmed by the state Senate. Florez was appointed by the state Senate. De La Torre was appointed by the state Assembly.

California Air Resources Board staffers estimated last year that the new rules could raise the price of a gallon of gas by as much as 47 cents next year. By 2040, the added cost to the price per gallon could be $1.80, staff members estimated in their 2023 document.

Since then, and again Friday, CARB officials asserted that those estimates were flawed and that they no longer believe the action will boost gas prices.

“Any claims that LCFS is responsible for high gas prices is misleading at best and not supported by the data,” Dillon Miner, CARB’s staff air pollution specialist, told the packed auditorium in Riverside on Friday.

Those assurances were met with skepticism by some speakers during the seven-hour public hearing.

Assemblymember Tom Lackey (R-Palmdale) told the board that residents of his district, many of whom were lower-income, often drove 100 miles a day.

“This is all about survival, financial survival,” Lackey said. “We simply cannot afford this.”

Nearly 13,000 Californians signed a petition written by Republican state senators that asked the board to postpone the vote until CARB provided information on how much the amendments would increase gas prices.

Even some Democrats spoke out about how the amendments could raise gas prices, which would especially burden low-income people who must drive to their jobs.

“I represent a working-class rural district that is largely dependent on agricultural jobs,” Assemblymember Esmeralda Soria (D-Merced) wrote in a Thursday letter to CARB Chair Liane Randolph. “It is these working families that can least afford even a modest increase in fuel prices.”

Many speakers at the public hearing urged the board to reject the amendments for reasons that did not involve the price of gasoline.

Some said they lived in the Inland Empire where the meeting was held. They spoke about how the pollution from trucks and other vehicles was continuing to harm the health of their families. They said they believed the program was benefiting companies by allowing them to continue to pollute and that the board should do more to support electric vehicles.

Environmentalists told the board they were disappointed that the amendments favored fuels such as renewable diesel that is made from food crops including soybeans and canola. Such biofuels result in turning land that was once used to grow food into that producing fuel.

Gary Hughes at BiofuelWatch told the board the plan would be “a driver of global deforestation” as more land was used to grow plants for the biofuel. “These fuels are not a climate solution,” he said.

Because of the LCFS, California now accounts for nearly all renewable diesel consumption in the U.S. Most of that fuel is not made in California but trucked in from other states or imported, mostly from Singapore.

“These dirty fuels are wolves in sheep’s clothing,” Nina Robertson of Earthjustice told the board.

Supporters of the amendments included dozens of executives from the producers of alternative fuels and electric vehicles, as well as other companies that have been financially benefiting from the program.

Steve Lesher of Shell U.S.A. told the board that the LCFS had prompted the oil company to invest in hydrogen and biofuel production, as well as electric vehicle charging stations. He called the program an “investment attractor.”

The LCFS program was created in 2009 under Republican Gov. Arnold Schwarzenegger. CARB says the program has resulted in more than 30 billion gallons of petroleum being displaced by low-carbon fuels. The program, the agency said, has also helped California reduce its greenhouse gas emissions by 20%.

The state uses a carbon-trading market to encourage producers to make the alternative fuels. Producers that don’t meet the state’s low carbon standard must buy credits from those who do, which pushes companies to develop cleaner options.

Under the current program, fuel producers had to reduce the carbon intensity of their fuels by 20% of the levels in 2010 by 2030.

The proposal approved Friday increased the carbon-intensity reduction target in 2030 to 30%. And the target would leap to 90% in 2045.

As the standard tightens, the cost of the credits is expected to rise. Critics say this cost will be passed on to consumers.

CARB officials say that isn’t correct. They say there is no direct relationship between the fuel credit prices and the cost of gas at the pump. And they say data show that the current fuel standard, before the amendments approved Friday, has added just 10 cents to the price of a gallon of gas.

Danny Cullenward, a climate economist in San Francisco and senior fellow at the Kleinman Center for Energy Policy at the University of Pennsylvania, estimated in an October report that under the new rules, the 2025 cost could be as high as 65 cents a gallon.

“It’s absolutely irresponsible and unacceptable that this board has chosen to ignore how its policies will impact gas prices,” state Sen. Rosilicie Ochoa Bogh (R-Yucaipa) said in a statement. “How can they possibly vote to approve it if they don’t even know what it will do to Californians at the pump?”