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.

DeLoyce Alcorn is 92 years old — and pressing nearly four times that in weight at the gym.

On a recent Wednesday afternoon, Alcorn — dressed in a T-Shirt that read “Be Strong. Be Resilient. Be You.” — slid into the leg press machine, which was set at a whopping 312 pounds. He gripped the handlebars, closed his eyes and “got zen,” as he says. Then he pressed his legs forward very slowly.

“Slower, slower, smoooooth ….” urged his his trainer, standing by his side.

The retired aerospace engineer, who lives in Sierra Madre, did about four reps before his teeth clenched, his legs trembled and he let out short puffs of air through pursed lips. The exercise was just one minute and thirty-three seconds long. When it was over, Alcorn sprung to his feet, beaming triumphantly.

“I used to do 400 pounds!” he boasted. “But the COVID, it put me back. I’m working my way back.”

Alcorn was in the midst of his weekly workout at the Strength Shoppe in Echo Park, where he and his wife, Patricia Alcorn, 88, have been training for 12 years. They’re devotees of an exercise called slow-motion strength training. Often referred to as SuperSlow or Power of Ten, the resistance training technique involves lifting weights very slowly and methodically, with 10 seconds each spent on the lifting and lowering motions of the exercise. Doing so eliminates momentum and is therefore easier on the joints and connective tissue — one reason many fans of slo-mo training are in their golden years.

The workout is typically done using MedX equipment, weight machines that were developed in the 1980s for rehabilitative purposes. They’re still used in physical therapy clinics, hospitals and gyms around the country.

Recently, strength training has become a hot topic in the world of exercise, in part because research continues to show its benefits for health and longevity. It builds muscle strength and bone density and is good for cardio metabolic health, especially for women. But slow-motion strength training, in particular, is beneficial for older exercisers, people healing injuries or those who are new to or returning to exercise because the slow cadence and focus on form — always with one-on-one supervision — reduces the chance of injury.

The method has also caught the attention of the wider exercise community because of its efficiency: a slow-motion workout is just 20 minutes long, once a week. It shouldn’t be done more than that, so the body has time to recover, says Melinda Hughes, co-owner of the Strength Shoppe. Slowing down the movement, eliminating momentum and not stopping to rest during an exercise set puts the muscle under greater tension for a longer period of time, forcing it to work harder, so exercisers may see greater benefit in less time compared with traditional strength training. Muscles typically fatigue from the exercise in just one to two minutes.

“Whereas traditional strength training takes three times the amount of time, with more reps and sets,” Hughes says, “and you don’t get to the level of intensity that you do with slow-motion strength training, where you just do one set to failure.”

Lai-San Ho on the rowing torso machine at the Workout Revolution with trainer Lorena Ortiz.

(The Workout Revolution )

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“It’s only 20 minutes. I can go on my lunch break!” says Lai-San Ho, a 33-year-old TV editor. She started slow-motion strength training at the Workout Revolution in Studio City after tearing her ACL in 2022 — it provided a low-impact way to exercise while recovering. But she stuck with it to stay fit.

“I could tell I was getting stronger in all areas of my body,” Ho says. “I’ve noticed certain aches and pains in my upper back, after a year, went away. I can’t imagine not doing it because I feel so many benefits.”

Jason Zaremski, a sports medicine physician at the University of Florida, says the technique is “legit, the real thing.”

“Any weight training is great for older individuals, but this routine reduces risk of injury while still gaining benefit,” he says. “There’s no jerky motions or throwing of weights. And it can increase your circulation — you get greater blood flow while activating your muscles. So you’re adding a cardiovascular benefit for something that’s typically anaerobic.”

Even so, other experts are skeptical about the technique.

“Sets going to failure, with a long time under tension, is a very uncomfortable, unnecessarily painful workout,” Casey Johnston, author of the weightlifting newsletter “She’s a Beast,” said. “It’s not necessarily more effective. So much of lifting is about coordination, neuromuscular activity in your body and stabilization and that’s not present using machines the way it is with free weights.”

DeLoyce Alcorn and his trainer, Arjen van Eijmeren, at the leg press machine.

(Marcus Ubungen/Los Angeles Times)

There are about a dozen boutique fitness studios in L.A. that specialize in slow-motion strength training, as well as larger chains like the Perfect Workout. Though many of them have been around for decades, momentum around this subset of exercise picked up during the COVID-19 pandemic, Hughes says, adding that by 2022, the Strength Shoppe had doubled its staff at both its Pasadena and Echo Park locations and this month opened a Mid-City location. While gyms and fitness studios closed during early stay-at-home orders, many slow-motion strength training studios remained open because they offered an essential rehabilitative service: weight-bearing physical therapy for pain management, osteoporosis and other conditions.

Word got out. Then, after restrictions lifted, those looking for in-person studios with strong COVID protections found their way to slow-motion strength training. The environment of a typical studio is quieter and more intimate than a bustling gym. No more than two clients and their trainers are typically allowed in the space at once. The temperature is set at a chilly 68-70 degrees, because body heat rises with such strenuous exertion. There are typically no group classes offered and no music over the loudspeakers.

“It’s so absolute attention can be paid to form and alignment,” Hughes says, adding that her clientele ranges from age 12 to 93. “I, and other trainers who work with this, call it ‘the fountain of youth.’ We lose muscle and bone density as we age. It’s cumulative. When you gain — or regain muscle mass — you feel younger, your body is more supported.”

Melinda Hughes and Arjen van Eijmeren, owners of the Strength Shoppe.

(Marcus Ubungen/Los Angeles Times)

At SuperSlowLA in Brentwood, which opened 25 years ago, the clientele ranges from age 15 to 89. But the studio specializes in the health of postmenopausal women, who make up 80% of its business (90% of its clients are female).

“Women get osteoporosis and osteopenia and other related health issues because of hormonal changes,” says owner Benjamin Fisher. “A lot of our clients are afraid of walking down the street and breaking a hip. The methodology of what we do, we keep bone loss at bay. We give them the strength to be more active and independent.”

Leona Katz, an 80-year-old attorney who has been training at SuperSlowLA for five years, calls the results “miraculous.”

“I was very overweight and had hip problems and blood pressure problems,” Katz says. “After my husband passed away, I made some life changes and lost more than 100 pounds. My kids call me Leona 2.0.”

At Myogenics Fitness, which opened in West Hollywood in 1998, the atmosphere is clean, simple and functional. Occasionally the studio will play white noise to help exercisers focus. Trainers coach clients on how to keep their breathing open and fluid while they lift.

“A lot of people compare it to mediating,” owner Chad Morris says of the workout.

Marty Waldman, 96, performs pull-downs at Myogenics Fitness.

(Carlin Stiehl/For The Times)

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Marty Waldman, 96, has been training at Myogenics for about six years, which has been “very gratifying but also exhausting” as a nonagenarian, he says. He was a runner, skier and long-distance biker when he was younger, and is in relatively good shape today but for a heart condition and “two bad knees and shoulders.” But the retired businessman began slo-mo strength training because he wanted to feel stronger.

“It’s allowed me to do things I wouldn’t ordinarily do,” he says. “We just got back from a rigorous trip with the gorillas in Rwanda — there’s no way I could have done that if I hadn’t been in reasonably decent shape.”

Chad Morris, owner of Myogenics Fitness, holds a stopwatch while training Marty Waldman, 96.

(Carlin Stiehl/For The Times)

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Though slow-motion strength training has delivered clear results for many of its participants, those results come with a price: Sessions must be done with a trainer and typically cost between $80 and $100, so that a month’s worth of sessions are more than a monthly gym membership.

There are safety precautions too.

Marty Waldman’s progress is recorded on his workout chart at Myogenics Fitness.

(Carlin Stiehl/For The Times)

“You can’t do the same amount of weight that you’d do with a traditional routine,” says sports medicine physician Zaremski. “You may have to drop the weight because your muscles will fatigue quicker — they’re under tension for a longer period. Your form also needs to be especially accurate.”

Still, devotees say the cost is worth it.

“You cannot put a price on health,” says Blake Boyd, a 58-year-old actor-producer and former fitness trainer who came to the Strength Shoppe six years ago after having been diagnosed with arthritis in his neck. “It’s effective, it works. I’ll do it for the rest of my life.”

Rick Staddon, owner of Vitality Personal Training in Calabasas, says his clients comment that getting stronger has been a game-changer.

“I often hear: ‘I can carry groceries up the stairs now,’ ‘I can cut the grass,’ he says. “The simple things are very meaningful for a lot of people.”

Alanna Kathleen Brown lifts weights at Pure Strength in Studio City.

(Deborah Vankin/Los Angeles Times)

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For Alanna Kathleen Brown, an 80-year-old retired English professor, slow-motion strength training has turned her into a “walking miracle,” she says, climbing onto the seat of the High Row machine at Pure Strength in Studio City.

“I have osteoarthritis, I deal with obesity, I have blood pressure issues and GERD,” Brown says. “But I do weights. I’m strong. I’ve avoided surgeries.”

Then she lifts and lowers the weight very slowly until her cheeks are flushed pink.

“For me, doing slow weights is right up there with paying all the bills,” she says. “I’d give up a lot of things before I’d give this up. Because it’s quality of life — and independence.”

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.