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October 25, 2016 / 23 Tishri, 5777

Posts Tagged ‘researchers’

TAU Researchers Decipher Malignant Melanoma

Tuesday, August 23rd, 2016

When malignant melanoma metastasizes to the brain, it is a death sentence for most patients. Metastatic melanoma is the deadliest of the skin cancers and the mechanisms that govern early metastatic growth and interactions of metastatic cells with the brain microenvironment remain shrouded in mystery.

A new Tel Aviv University study reveals a novel way of detecting brain micrometastases months before they transform into malignant inoperable growths. According to the research, micro-tumor cells hijack astrogliosis, the brain’s natural response to damage or injury, to support metastatic growth. This knowledge may lead to the detection of brain cancer in its first stages and permit early intervention.

The study was led by Dr. Neta Erez of the Department of Pathology at TAU’s Sackler Faculty of Medicine and published in Cancer Research.

Following the path to cancer

Dr. Erez and her team used mouse models to study and follow the spontaneous metastasis of melanoma in the brain. She and her partners recapitulated all the stages of metastasis: the initial discovery of melanoma in the skin, the removal of the primary tumor, the micrometastatic dissemination of cancer cells across the body, the discovery of a tumor and death.

The detection of metastasis depends on imaging techniques that still can’t detect micrometastases. Melanoma patients whose initial melanoma was excised believe that everything is fine for months or years following the initial procedure.

But following the removal of the primary tumor, micrometastatic cells learn to communicate with cells in their new microenvironment in the brain — cells which are, at first, hostile to them. But eventually a tumor appears. These cells travelled across the body to the brain or other organs but were undetectable at the micro level. When they become detectable, it is too late for treatment.

Opening the “black box”

Dr. Erez calls the period of the initial growth of disseminated micrometastatic cells in distant organs the metastasis’ “black box” — the history of melanoma in the brain. “We believe that we have found the tools to characterize this black box,” said Dr. Erez. “And this is key to developing therapeutic approaches that may prevent brain metastatic relapse.

“Every organ in body has a defense system that detects intruders,” said Dr. Erez. “Much of this is regulated by support cells in the brain. When there is tissue damage due to a stroke or viral infection, these cells are activated and induce an inflammatory response.

“At the earliest stages of metastasis, we already see astrogliosis and inflammation. The brain perceives the micrometastatic invasion as tissue damage, activating inflammation — its natural defense mechanism. We found that the inflammation unfortunately gets hijacked by tumor cells that are able to grow faster and penetrate deeper because the blood vessels in the brain are more permeable than in any other part of the body. We found that all of this happens very early on.”

Dr. Erez is currently studying detailed molecular pathways in the brain’s biological response to find a way to block the metastases. “We’re hoping to develop the detection tools for humans that we developed in mice,” said Dr. Erez. “We’re also trying to find molecular targets that will allow us to prevent metastasis rather than trying to treat it.”

This article was originally published by AFTAU.

David Israel

Israel-Japan Researchers Teaming on Autism and Brain Research

Wednesday, January 21st, 2015

Israeli and Japanese researchers are teaming on a project to learn how autistic spectrum disorder develops in the brain.

The prevalence of autistic spectrum disorders has been steadily rising; in most parts of the world rates as high as 1 percent are reported, including in the United States. In Israel, previously reported prevalence rates have been in the 0.2 percent rage and were  based on parental reporting of diagnosis. However, they too appear to be rising.

The scientists met together at a conference that convened following a visit to Israel by japan’s Prime Minister Shinzo Abe.

A group of leading Japanese scientists arrived at the Weizmann Institute of Science late last week  to attend the Advances in Brain Sciences conference, which was  was jointly hosted by Weizmann in Rehovot and the RIKEN Brain Science Institute in Japan.

Weizmann’s conference co-organizer Dr. Ofer Yizhar is currently involved in the collaborative research project with RIKEN researcher Toru Takumi. The joint project is aimed at determining which neural mechanisms are involved in autistic spectrum disorder behaviorisms, Yizhar explained.

“Takumi creates mice that have a genetic defect which mimics autism,” he explained, “while my optogenetics lab can work with these mice, turning neurons in the brain ‘on’ and ‘off’ with light.”

There were a number of other presentations at the conference as well.

Keynote speaker Professor Shimon Ullman (Weizmann) spoke on visual recognition, a subject that crosses the boundaries between neuroscience and artificial intelligence. Ullman has worked with RIKEN’s Dr. Manabu Tanifuji for a number of years. “Scientificc and personal connections have deepened over the years,” he said, “and we are currently planning the next steps of joint work in the future.”

In 2010, prevalence rates for autistic spectrum disorders in Israel were found to be 0.65 percent in eight year old children, and 0.48 percent in children ages 1 to 12, per 1,000 children, according to an article published in 2013 in the Journal of Autism and Development Disorders.

The article, entitled ‘Prevalence and incidence of autism spectrum disorder in an Israeli population, listed the findings of a study of records from the Maccabi Health Maintenance Organization (HMO / kupat holim) Child Neurology and Development, Child Development Center, Jerusalem and Shfela District.

Canada-Israel Autism Research Symposium was also held for the first time last March at The Hebrew University in Jerusalem, jointly sponsored by the Autism and Neurodevelopmental Disorders Research Hub at the Institute for Medical Research Israel-Canada and the Canadian Friends of The Hebrew University.

Hana Levi Julian

Ancient Monument Underwater in the Kinneret

Friday, April 12th, 2013

Israel Antiquity Authority researchers revealed on Thursday the existence of a mysterious rock pile, 30 ft. tall and more than 200 ft. in diameter, comprised of “unhewn basalt cobbles and boulders” weighing an estimated 60 thousand tons, according to the International Journal of Nautical Archaeology.

Archeologist Yitzhak Paz said that the structure could be 4000 years old, similar to ancient structures that have been found nearby.

We assume that 6–9 ft. of sand that covers the base of the cairn accumulated naturally after its construction. The sediment accumulation rates in lakes vary in space and time. The location of the structure is not associated with any stream which could supply sediment. Therefore, long-shore currents and suspended particulate matter are the plausible sources. An interesting observation from the Ohalo II site is the deposition of 20 cm of sand within a single winter on top of plastic sheets that were placed to cover the excavations. We believe that this event does not represent the long-term deposition rate. Assuming an accumulation rate of 1–4 mm/yr, construction may have taken place between two and 12 millennia ago.

Location maps: a) The Sea of Galilee is a fault-bounded basin (faults shown with solid white lines). The River Jordan (J, dotted line), the main water supplier to the lake, enters at the north and exits southward. Shaded topography from Hall (1994). (Shmuel Marco); b) The lake bathymetric map based on multi beam survey (after Sade et al., 2008) with the location of the monumental structure (red). (Shmuel Marco)

Location maps: a) The Sea of Galilee is a fault-bounded basin (faults shown with solid white lines). The River Jordan (J, dotted line), the main water supplier to the lake, enters at the north and exits southward. Shaded topography from Hall (1994). (Shmuel Marco); b) The lake bathymetric map based on multi beam survey (after Sade et al., 2008) with the location of the monumental structure (red). (Shmuel Marco)

The researchers said that the shape and composition of the underwater structure does not appear to be a natural formation, concluding that it is man-made, possibly an ancient cairn – a man-made stack of stones. Its age and purpose are not known.

A schematic section with approximate proportions of the structure. (Shmuel Marco)

Schematic section w. approximate proportions of the structure. (Shmuel Marco)

Two speculations so far have been that it was either built under water to attract fish, or built on dry land, and then covered by the rising sea water.

The structure was first spotted in a 2003 sonar scan of the Kinneret. The structure is comprised of large boulders, each around 3 ft. long, without a discernable construction pattern.

The researchers wrote in their paper that effort invested in such an enterprise is indicative of a complex, well-organized society, with planning skills and economic ability.

The researchers point out that the Kinneret discovery is just north of the site of the ancient city Beit Yerach (house of the moon god):

The possible relation of the submerged stone structure to the ancient settlements along the shores of the Sea of Galilee is of great importance. Flourishing settlement systems existed along the shores in the Bronze and Iron Ages, between the 4th and the 1st millennia BCE. Urban centers such as Bet Yerach, Tel Hadar and Bethsaida were the prominent settlements in Biblical periods

Beit-Yerach was one of the most remarkable Bronze age sites in Israel. Its large size (80 acres), massive brick walls (24 ft. wide), natural protection (surrounded by water), and strategic location (cross roads passing the southern side of the Kinneret), made it one of the strongest cities 4 thousand years ago.

Yori Yanover

Printed from: http://www.jewishpress.com/news/breaking-news/ancient-monument-underwater-in-the-kinneret/2013/04/12/

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