New Blood Test Could Replace Biopsies

No one enjoys getting a biopsy, in which a tissue sample is surgically taken and analyzed in a lab for signs of disease, such as cancer. It’s not only unpleasant for the patient, but has clinical drawbacks: A biopsy doesn’t always extract the diseased tissue and isn’t helpful in detecting disease at early stages. These concerns have encouraged researchers to find less invasive and more accurate diagnostic methods. Prof. Nir Friedman and Ronen Sadeh of the Hebrew University of Jerusalem have developed a blood test that enables lab technicians to diagnose cancer and diseases of the heart and liver by identifying and determining the state of the dead cells throughout the body.

Millions of cells die every day and are replaced by new cells. When cells die, their DNA is fragmented. Some of these DNA fragments reach the blood and can be “read” by advanced DNA sequencing methods.

As a result of these scientific advancements, we understood that if this information is maintained within the DNA structure in the blood, we could use that data to determine the tissue source of dead cells and the genes that were active in those very cells. Based on those findings, we can uncover key details about the patient’s health,” Friedman said.

We are able to better understand why the cells died — whether it’s an infection or cancer — and based on that, be better positioned to determine how the disease is developing,” he said. Co-author Israa Sharkia added the simple blood test could “be administered often and quickly, allowing the medical staff involved to follow the presence or development of a disease more closely.”

A startup company, Senseera, has been established to pursue clinical testing of this innovative approach in partnership with major pharmaceutical companies.

The multi-author study published in Nature Biotechnology explains the test can even identify markers that may differentiate between patients with similar tumors, which could help physicians develop personalized treatments.

Source: https://www.zenger.news/

Coronavirus Uses Same Strategy As HIV To Dodge Immune Response

The novel coronavirus uses the same strategy to evade attack from the human immune system as HIV, according to a new study by Chinese scientists.

Both viruses remove marker molecules on the surface of an infected cell that are used by the immune system to identify invaders, the researchers said in a non-peer reviewed paper posted on preprint website bioRxiv.org on Sunday. They warned that this commonality could mean Sars-CoV-2, the clinical name for the virus, could be around for some time, like HIV.

Virologist Zhang Hui and a team from Sun Yat-sen University in Guangzhou also said their discovery added weight to clinical observations that the coronavirus was showing “some characteristics of viruses causing chronic infection”.

Their research involved collecting killer T cells from five patients who had recently recovered from Covid-19, the disease caused by the virus. Those immune cells are generated by people after they are infected with Sars-CoV-2 – their job is to find and destroy the virus.

The molecule is an identification tag usually present in the membrane of a healthy cell, or in sick cells infected by other coronaviruses such as severe acute respiratory syndrome, or Sars. It changes with infections, alerting the immune system whether a cell is healthy or infected by a virusHIV uses the same strategyMHC molecules are also absent in cells infected with that virusIn contrast, Sars does not make use of this function,” Zhang said.

The coronavirus removes these markers by producing a protein known as ORF8, which binds with MHC molecules, then pulls them inside the infected cell and destroys them, the researchers said. ORF8 is known to play an important role in viral replication, and most commercial test kits target this gene to detect viral loads in nose or oral swabs.

While drugs being used to treat Covid-19 patients mainly targeted enzymes or structural proteins needed for viral replication, Zhang and his team suggested compounds be developedspecifically targeting the impairment of MHC by ORF8, and therefore enhancing immune surveillance for Sars-CoV-2 infection”.

Source: https://www.scmp.com/

How To Early Detect Prostate Cancer

For the first time, a team of scientists at the University of Central Florida has created functional nanomaterials with hollow interiors that can be used to create highly sensitive biosensors for early cancer detection. Xiaohu Xia, an assistant professor of chemistry with a joint appointment in the NanoScience Technology Center, and his team developed the new method and recently published their work in the journal ACS Nano.

These advanced hollow nanomaterials hold great potential to enable high-performance technologies in various areas,” says Xia. “Potentially we could be talking about a better and less expensive diagnostic tool, sensitive enough to detect biomarkers at low concentrations, which could make it invaluable for early detection of cancers and infectious diseases.”

Because hollow nanomaterials made of gold and silver alloys display superior optical properties, they could be particularly good for developing better test strip technology, similar to over-the-counter pregnancy tests. Currently the technology used to indicate positive or negative symbols on the test stick is not sensitive enough to pick up markers that indicate certain types of cancer. But Xia’s new method of creating hollow nanomaterials could change that. More advance warning could help doctors save more lives.

In conventional test strips, solid gold nanoparticles are often used as labels, where they are connected with antibodies and specifically generate color signal due to an optical phenomenon called localized surface plasmon resonance. Under Xia’s technique, metallic nanomaterials can be crafted with hollow interiors. Compared to the solid counterparts, these hollow nanostructures possess much stronger LSPR activities and thus offer more intense color signal. Therefore, when the hollow nanomaterials are used as labels in test strips they can induce sensitive color change, enabling the strips to detect biomarkers at lower concentrations.

Test-strip technology gets upgraded by simply replacing solid gold nanoparticles with the unique hollow nanoparticles, while all other components of a test strip are kept unchanged,” says Xia. “Just like the pregnancy test, the new test strip can be performed by non-skilled persons, and the results can be determined with the naked eye without the need of any equipment. These features make the strip extremely suitable for use in challenging locations such as remote villages.”

The UCF study focused on prostate-specific antigen, a biomarker for prostate cancer. The new test strip based on hollow nanomaterials was able to detect PSA as low as 0.1 nanogram per milliliter (ng/mL), which is sufficiently sensitive for clinical diagnostics of prostate cancer. The published study includes electron microscope images of the metallic hollow nanomaterials.

“I hope that by providing a general and versatile platform to engineer functional hollow nanomaterials with desired properties, new research with the potential for other applications beyond biosensing can be launched,” Xia says.

Source: https://www.ucf.edu/