Medical Bulletin 28/May/2025

In a medical breakthrough, surgeons from Keck Medicine of USC and UCLA Health have performed the world’s first human bladder transplant. The pioneering operation took place on 4th May 2025 at Ronald Reagan UCLA Medical Center and involved a collaborative effort led by Dr Inderbir Gill and Dr Nima Nassiri.

The patient, who had been reliant on dialysis for seven years and had lost his bladder function due to cancer, received both a kidney and bladder transplant. The eight-hour procedure involved transplanting the kidney first, followed by the bladder, with the new organs then connected. The kidney began functioning immediately, producing urine for the first time in years, with no need for further dialysis.

Gill described the event as a “historic moment in medicine,” potentially transforming treatment options for patients with severely damaged or non-functioning bladders. Until now, such patients often required bladder reconstruction using intestinal tissue, which carries significant risks, including infections and impaired kidney function.

Nassiri, who helped develop the new technique over several years, highlighted the promise this procedure holds: “For the appropriately selected patient, it is exciting to be able to offer a new potential option.”

This transplant was the result of years of collaborative research, including robotic surgical trials and practice runs using donor organs. Despite the unknowns around long-term bladder function and immunosuppression needs, the success of this first case opens the door for future bladder transplants.

Gill and Nassiri now plan to continue this work through further clinical trials, offering new hope to patients suffering from debilitating bladder conditions.

Reference: Keck Medicine of USC. USC, UCLA team up for the world’s first-in-human bladder transplant. Available at: https://news.keckmedicine.org/usc-ucla-team-up-for-the-worlds-first-in-human-bladder-transplant/. Last accessed: 19 May 2025.

New Dental Floss Sensor Tracks Stress Hormone Cortisol in Real Time: Study

A team led by Tufts University engineer Sameer Sonkusale has developed an innovative, real-time stress monitoring device that uses a simple floss pick to detect cortisol levels in saliva. The research, published in ACS Applied Materials and Interfaces, offers a low-cost, non-invasive, and highly accurate alternative to traditional stress assessment tools, which often rely on subjective self-reporting or expensive medical evaluations.

Their design of a saliva-sensing dental floss looks just like a common floss pick, with the string stretched across two prongs extending from a flat plastic handle, all about the size of your index finger. The saliva is picked up by capillary action through a very narrow channel in the floss. The fluid is drawn into the pick handle and an attached tab, where it spreads across electrodes that detect the cortisol.

Cortisol recognition on the electrodes is accomplished with a remarkable technology developed almost 30 years ago called electropolymerized molecularly imprinted polymers (eMIPs). They work similarly to the way you might make a plaster cast of your hand. A polymer is formed around a template molecule, in this case cortisol, which is later removed to leave behind binding sites. These sites have a physical and chemical shape "memory" of the target molecule so they can bind free-floating molecules that are coming in.

"The eMIP approach is a game changer," said Sonkusale, professor of electrical and computer engineering. Unlike traditional biosensors that rely on engineered antibodies or receptors, eMIPs enable faster and more flexible sensor development. The technology can also be adapted to detect other biomarkers in saliva, including estrogen, glucose, or cancer indicators.

Sonkusale emphasized that while blood remains the "gold standard" for diagnosis, saliva-based monitoring provides an easy, non-invasive way to track health changes over time. “If you need to track, say, a cardiovascular condition over time to see if your heart health is improving, then monitoring with the sensor can be easy and allows for timely interventions when needed.”

Reference: Atul Sharma, Nafize Ishtiaque Hossain, Ayanna Thomas, Sameer Sonkusale. Saliva-Sensing Dental Floss: An Innovative Tool for Assessing Stress via On-Demand Salivary Cortisol Measurement with Molecularly Imprinted Polymer and Thread Microfluidics Integration. ACS Applied Materials & Interfaces, 2025; 17 (17): 25083 DOI: 10.1021/acsami.5c02988

Study Reveals Why Your Immune System Works Better in Daylight?

A new study has revealed that the immune system is regulated by a circadian clock and becomes more active during daylight hours. The research, published in Science Immunology, shows that neutrophils—the body’s most abundant white blood cells—are influenced by light, which enhances their ability to fight infections.

The study, led by Associate Professor Christopher Hall from the Department of Molecular Medicine and Pathology, used zebrafish as a model organism due to their genetic similarities to humans and their transparent bodies, which allow real-time observation of biological processes.

Researchers discovered that neutrophils possess their own circadian clock, which senses daytime and boosts their antibacterial activity. This internal timing mechanism is influenced primarily by light, which is known to be the strongest factor in resetting circadian rhythms across most cells in the body.

"Given that neutrophils are the first immune cells to be recruited to sites of inflammation, our discovery has very broad implications for therapeutic benefit in many inflammatory diseases," says Hall.

The team believes that manipulating the circadian clock in neutrophils could lead to new treatments for infectious and inflammatory conditions. “This finding paves the way for development of drugs that target the circadian clock in neutrophils to boost their ability to fight infections,” Hall adds.

Reference: Lucia Yi Du, Pramuk Keerthisinghe, Leah Rolland, Yih Jian Sung, Hannah Darroch, Tanja Linnerz, Elina Ashimbayeva, Matthew J. Grant, Purvi M. Kakadia, Annasuya Ramachandran, Alexander Tups, Herman P. Spaink, Stefan K. Bohlander, James Cheeseman, Philip S. Crosier, Jonathan W. Astin, Guy Warman, Christopher J. Hall. A light-regulated circadian timer optimizes neutrophil bactericidal activity to boost daytime immunity. Science Immunology, 2025; 10 (107) DOI: 10.1126/sciimmunol.adn3080