New hand-held device uses lasers, sound waves for deeper melanoma imaging

Handheld probe
A photograph of the handheld probe. The motor, translation stage, ultrasonic transducer, and optical fibers are all incorporated in this handheld probe for easy operation.

Melanoma is the deadliest form of skin cancer, causing more than 75 percent of skin-cancer deaths. The thicker the melanoma tumor, the more likely it will spread and the deadlier it becomes. Now, a team of researchers has developed a new hand-held device that uses lasers and sound waves that may change the way doctors treat and diagnose melanoma. The tool is ready for commercialization and clinical trials.

A new hand-held device that uses lasers and sound waves may change the way doctors treat and diagnose melanoma, according to a team of researchers from Washington University in St. Louis. The instrument, described in a paper published today in The Optical Society’s (OSA) journal Optics Letters, is the first that can be used directly on a patient and accurately measure how deep a melanoma tumor extends into the skin, providing valuable information for treatment, diagnosis or prognosis.

Melanoma is the fifth most common cancer type in the United States, and incidence rates are rising faster than those of any other cancer. It’s also the deadliest form of skin cancer, causing more than 75 percent of skin-cancer deaths.

The thicker the melanoma tumor, the more likely it will spread and the deadlier it becomes, says dermatologist Lynn Cornelius, one of the study’s coauthors. Being able to measure the depth of the tumor in vivo enables doctors to determine prognoses more accurately — potentially at the time of initial evaluation — and plan treatments and surgeries accordingly.

The problem is that current methods can’t directly measure a patient’s tumor very well. Because skin scatters light, high-resolution optical techniques don’t reach deep enough. “None are really sufficient to provide the two to four millimeter penetration that’s at least required for melanoma diagnosis, prognosis or surgical planning,” says engineer Lihong Wang, another coauthor on the Optics Letters paper. Continue reading

Can we eat to starve cancer?

Impressive 15min TED Talk given by William Li who presents a new way to think about treating cancer and other diseases: anti-angiogenesis, preventing the growth of blood vessels that feed a tumor. The crucial first (and best) step: Eating cancer-fighting foods that cut off the supply lines and beat cancer at its own game.

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First chromosome made synthetically from yeast


Baker’s yeast, Saccharomyces cerevisiae, seen under a microscope, ferment fruit and grain into alcohol and make bread rise. Now researchers have taken the first step toward making a synthetic version of the organism that may perform feats regular yeast never could.

Designer organisms have crept closer to reality. Scientists have stitched together a version of a yeast chromosome. It is the first synthetic chromosome ever assembled from a eukaryotic organism, the type in which cells store DNA in nuclei. Other groups have previously synthesized chromosomes from bacteria, but this is the first step in designing synthetic eukaryotes.

Researchers from Johns Hopkins University, including a small army of undergraduate students, and colleagues report the achievement March 27 in Science. The synthetic chromosome is based on chromosome III from the yeast Saccharomyces cerevisiae, but it is not an exact replica. See the article.

Source/Photo: Science News

The Legacy of HeLa


by Lisa Winter

Henrietta Lacks was integral to the formulation of the polio vaccine, cloning, mapping genes, biomedical ethics, the field of virology, and many other facets of modern medicine. But, she never looked down a microscope. She never invented anything. She never authored a scientific paper. She was not a scientist of any kind. Why is she featured on this website? In 1951, before she lost her fight with cervical cancer, samples were taken from her body, and that cell line is still alive today.

Traditionally, human cells had been difficult to culture. They died after a few short days, prohibiting long term experiments. However, when Dr. George Gey of Johns Hopkins University collected cells from Henrietta Lacks (and abbreviated the tube as HeLa), a lineage of cancer cells was discovered that had incredible resilience. The cells grew so quickly and readily, they were able to be distributed to scientists around the world for experimentation free of charge — without Henrietta’s knowledge or consent. At the time, bioethical standards were starting to come together. While informed consent may have been recommended, it was not required. The samples which had an abnormal longevity were eventually sent to laboratories around the world without the knowledge or consent of Henrietta or her family.

Why are these cells considered “immortal”? When DNA replicates, the telomeres at the end of chromosomes shorten with every round. After about 50 divisions, typical human cells reach what is known as the Hayflick Limit, where the telomeres have become too short to divide, and the cell undergoes apoptosis. Cancer cells do not respond in the same way. This, combined with the natural strength of Henrietta’s cells, has resulted in a cell lineage that has remained hardy throughout the years.

As of today, Henrietta’s cells have lived outside her body for over 60 years; twice as long as they lived inside her body. There are now other long lasting human cell lineages studied by scientists, but HeLa cells were the first, and continue to be the most popular.

As genomic sequencing has become more commonplace, questions about the Lacks family’s privacy have come to the forefront. Earlier this year, papers published HeLa’s genome without first getting authorization from the family. After months of negotiations, it was announced last month that research dealing with the sequence can continue. The only caveat is that the work has to promote the greater good for humanity and researchers must do whatever they can to ensure the Lacks’ privacy.