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Category: biotech/medical – Page 31

Advances in Clinical Oncology Research on 99mTc3PRGD2 SPECT Imaging

Cancer is currently the leading cause of death worldwide, with a global estimated 19.3 million new cancer cases and almost 10.0 million cancer deaths recorded in 2020 (). Early detection, diagnosis, and treatment are key measures for reducing mortality attributed to malignant tumors and prolonging survival time. The integrin alpha(α)v beta(β)3 receptor is frequently involved in the occurrence and development of malignant tumors (, ); it mediates cell–cell and cell–extracellular matrix adhesion (, ) and is related to tumor angiogenesis and metastasis (, – ). The integrin αvβ3 receptor is highly expressed in activated endothelial cells and proliferating tumor cells; however, it is either not expressed or expressed at very low levels in normal endothelial cells, dormant vascular cells, and other normal cells (, ) and has a certain level of specificity. Therefore, the integrin αvβ3 receptor is a valuable target for diagnosing and treating malignant tumors.

Polypeptides containing the arginine-glycine-aspartate (Arg-Gly-Asp [RGD]) sequence can bind specifically to the integrin αvβ3 receptor with high selectivity and strong affinity (). Hence, these polypeptides can specifically demarcate lesions and their angiogenesis for tumor detection and have promising prospects for tumor diagnosis and treatment. Radiolabeled RGD peptides and their analogs have been intensively studied for their application in the non-invasive imaging of integrin αvβ3 receptor expression (– ).

The technetium-99m hydrazinonicotinamide-dimeric cyclic RGD peptide with three polyethylene glycol spacers (99m Tc-3PRGD2) is a 99m Tc-labeled molecular probe used in nuclear medicine for single-photon emission computed tomography (SPECT). Its core ligand, hydrazinonicotinamide-3PRGD2, is a new type of RGD dimer that can bind specifically to the integrin αvβ3 receptor with high selectivity and affinity. In addition, 99m Tc-3PRGD2 has rapid blood clearance and a high level of safety with no adverse reactions having been observed in animal models and humans to date (, ). 99m Tc-3PRGD2 SPECT imaging is widely used in clinical research because of its high diagnostic performance and excellent cost-effectiveness, which further highlight its potential for clinical applications. Herein, we review the advances in clinical research on 99m Tc-3PRGD2 SPECT imaging for tumor lesions over the past decade.

Neuron discovery could explain why some people don’t get Alzheimer’s

Some brains seem to defy Alzheimer’s. Even when the disease’s telltale plaques and tangles are present, certain individuals remain mentally sharp well into old age. This phenomenon, known as cognitive resilience, is one of the most intriguing puzzles in neuroscience today.

At the Netherlands Institute for Neuroscience, researchers led by neuroscientist Evgenia Salta have uncovered new clues. Their work suggests that resilience may depend not on the sheer number of brain cells, but on how a special class of cells, called immature neurons, respond to damage.

For decades, neuroscientists have debated whether the adult human brain retains any meaningful population of “immature” neurons, youthful-looking cells tucked inside the hippocampus.

Mechanisms Underlying an Enhanced NavigationBased Intervention to Improve Timely Adjuvant Therapy

This secondary analysis of a randomized clinical trial examines the mechanisms by which Navigation for Disparities and Untimely Radiation Therapy (NDURE) improved timely postoperative radiation therapy relative to usual care navigation among patients with head and neck squamous cell carcinoma.

JCI: Address correspondence to: Moshe Arditi, 8,700 Beverly Blvd., Davis Building, Rooms D4024, D4025, D4027, Los Angeles, California 90,048, USA

Phone: 310.423.4471; Email: [email protected]. BK’s present address is: Department of Basic Oncology, Hacettepe University Cancer Institute, Ankara, Turkey. RAP’s present address is: NCI-designated Cancer Center; Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.

Effective treatment of glioblastoma requires crossing the blood–brain barrier and targeting tumors including cancer stem cells: The promise of nanomedicine

Glioblastoma multiforme (GBM) is the most aggressive and lethal type of brain tumor. Both therapeutic resistance and restricted permeation of drugs across the blood–brain barrier (BBB) play a major role in the poor prognosis of GBM patients. Accumulated evidence suggests that in many human cancers, including GBM, therapeutic resistance can be attributed to a small fraction of cancer cells known as cancer stem cells (CSCs). CSCs have been shown to have stem cell-like properties that enable them to evade traditional cytotoxic therapies, and so new CSC-directed anti-cancer therapies are needed. Nanoparticles have been designed to selectively deliver payloads to relevant target cells in the body, and there is considerable interest in the use of nanoparticles for CSC-directed anti-cancer therapies.

Scientists identify fructose as a surprise driver of cancer spread

A new study from The Wistar Institute has uncovered an unexpected link between fructose—a common dietary sugar—and the spread of an aggressive form of ovarian cancer. Published in Nature Aging, the study found that cancer cells not killed by chemotherapy send signals to neighboring tumor cells, helping them become more capable of spreading.

The researchers identified fructose as a key messenger in this process, revealing a previously unrecognized way that treatment-surviving cancer cells may promote the spread of cancer.

“Some cancer cells that survive chemotherapy aren’t dividing anymore, but they’re still biologically active,” said Aidan Cole, a postdoctoral fellow in the lab of Katherine Aird at The Wistar Institute and first author of the study. “Instead, they continue to release molecules that send signals to nearby cells. Our study is among the first to show that a nutrient—in this case, fructose—can act as one of those signals.”

All living things emit a faint glow. Could this light be useful?

An interesting report on the phenomenon by which cells and organisms glow very faintly, primarily due to energy transitions during aerobic respiration. Speculation on biological functions and future applications are covered.

Ultra-weak ‘biophotons’ might be used to diagnose disease, or could even represent a new signalling mechanism in cells.

Researchers Simulate Alzheimer’s Progression Across the Entire Brain

This hypothesis has led to a new “whole-brain” mathematical and computational model developed at the MOX Laboratory of the Department of Mathematics of Politecnico di Milano. The model is designed to describe in an integrated way the interaction between the spread of amyloid beta and the functioning of the cerebral vascular network. The aim is to provide a tool capable of simulating, on the scale of the whole organ, how small biological or vascular alterations can evolve over time and contribute to neurodegeneration. The model and the accompanying scientific study have been published in the prestigious scientific journal Computer Methods in Applied Mechanics and Engineering.

The model integrates two scales of analysis. On the one hand, it describes the dynamics of the production, transformation, diffusion and elimination of the healthy and pathological forms of amyloid beta. On the other, it describes blood flow through a “macroscopic” description of arteries, capillaries and veins, treating brain tissue as a porous medium perfused by blood vessels, through a macroscopic compartmental model. The two components are then connected to represent the possible mechanism of mutual reinforcement between protein accumulation and vascular dysfunction.

The simulations show a particularly relevant result: the brain can evolve into different states depending on the initial conditions. Small localised amounts of amyloid beta can be eliminated, allowing the system to return to a healthy state. Conversely, larger amounts can trigger a self-sustained spread of the pathology at brain scale.

Quantum in the palm of your hand: The evolution of superconducting qubits

Electrons zipping through transistors, powering the screens on our smartphones. Light zooming from distant stars to Earth, moving faster than anything else in the universe. Protons enabling MRI machines to analyze people’s injuries.

Quantum mechanics explains the behavior of subatomic particles like electrons, photons and protons. In contrast to classical physics that we can observe with our senses, particles in the quantum realm have unusual behaviors. Even though quantum particles make common technologies possible, we don’t experience these behaviors in our everyday world.

That’s why a discovery in 1985 was such a big deal. In a laboratory at the University of California, Berkeley, a team of three scientists showed that a system you could see could demonstrate quantum behavior. Or as they said in one of the journal articles covering the experiments, the system was “big enough to get one’s grubby fingers on.”

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