Group items tagged

In a paper this week in Science, Vogelstein and Cristian Tomasetti, who joined the biostatistics department at Hopkins in 2013, put forth a mathematical formula to explain the genesis of cancer. Here's how it works: Take the number of cells in an organ, identify what percentage of them are long-lived stem cells, and determine how many times the stem cells divide. With every division, there's a risk of a cancer-causing mutation in a daughter cell. Thus, Tomasetti and Vogelstein reasoned, the tissues that host the greatest number of stem cell divisions are those most vulnerable to cancer. When Tomasetti crunched the numbers and compared them with actual cancer statistics, he concluded that this theory explained two-thirds of all cancers.

Cold Spring Harbour cancer site, sections include: Hallmarks of Cancer Causes and Prevention Diagnosis and Treatment Pathways to Cancer

This flipped case study begins with a video in which a student reveals a family member's diagnosis with breast cancer and then considers the whirlwind of questions that arise in such a situation. Students are asked to relate to the main character and identify what questions they would have and what resources they could consult to seek information.  This sets the context for students to use websites and videos to investigate the nature of cancer, its causes, and progression. Students then learn about the major methods of cancer treatment (surgery, radiation therapy, and chemotherapy), how they work, and the limitations and side effects of each. The case concludes by addressing the claim of one of the characters that there is a conspiracy to hide a cure for cancer. The case would be implemented near the middle of a high school, non-majors, or introductory biology course after discussion of basic cell biology and the cell cycle.

Some 20 percent of cancer-related deaths in the U.S. can be attributed to obesity, making it the number-one preventable cause of cancer death in the country. But with myriad metabolic and inflammatory changes associated with obesity, determining the mechanisms that underlie the obesity-cancer link has proven challenging.

In the 2013 Holiday Lectures on Science, Charles L. Sawyers of Memorial Sloan-Kettering Cancer Center and Christopher A. Walsh of Boston Children's Hospital will reveal the breathtaking pace of discoveries into the genetic causes of various types of cancers and diseases of the nervous system, and discuss the impact of those discoveries on our understanding of normal human development and disease.

How do cancer cells grow? How does chemotherapy fight cancer (and cause negative side effects)? The answers lie in cell division. George Zaidan explains how rapid cell division is cancer's "strength" -- and also its weakness.

This clicker case was designed to teach students about basic enzyme structure, mechanisms of enzyme inhibition, and mechanisms of drug resistance. The story follows Oliver Casey, a patient afflicted with Chronic Myelogenous Leukemia (CML). CML is caused by a chromosomal mutation that affects the tyrosine kinase ABL, an enzyme important in regulating cell growth and proliferation. The chromosomal mutation gives rise to the BCR-ABL fusion gene that produces a constitutively active ABL kinase, which causes the leukemia. In May 2001, the Food and Drug Administration approved the use of a rationally designed tyrosine kinase inhibitor, imatinib (Gleevec®), for the treatment of CML. During that same month, Gleevec made the cover of TIME magazine, described as "new ammunition in the war on cancer." The case is structured for a flipped classroom environment in which students view preparatory videos (including one by the author) on their own before beginning the case. Written for a first-year introductory biology course, the case could also be adapted for AP/Honors high school biology or a cancer biology course.

Most colon cancers may be caused by infections with bacteria that are normally found in cows. For decades we have known that Streptococcus gallolyticus gallolyticus (SGG) is sometimes found in colon tumours, but now the microbes have been found to directly cause tumour growth in mice.

Book section on NCBI

4:17 video Think of the ozone layer as Earth's sunglasses, protecting life on the surface from the harmful glare of the sun's strongest ultraviolet rays, which can cause skin cancer and other maladies. Ozone stinks. People who breathe it gag as their lungs burn. The EPA classifies ground-level ozone as air pollution. Yet without it, life on Earth would be impossible. A fragile layer of ozone 25 km above Earth's surface is all that stands between us and some of the harshest UV rays from the sun. The ozone molecule O3 blocks radiation which would otherwise burn skin and cause cancer. On Mars, which has no ozone layer to protect it, solar UV rays strafe the surface with deadly effect, leaving the apparently lifeless planet without the simplest of organic molecules in the upper millimeters of exposed Martian soil.

Many biology courses are designed to develop student understanding and application of the scientific method, but few seriously examine the various ethical questions associated with scientific research. This interdisciplinary case study presents three experiments and asks not only if they are scientifically valid but whether they were ethically performed.  The experiments examine the psychology of love, a cause of breast cancer, and how the immune system functions in the presence of cancer. Based on their opinions of the validity and ethics of each experiment, students are asked to conclude which of the experiments were actually conducted by scientists and which are fictional. Students should already be familiar with the scientific method, but information on the Georgetown Mantra and Nuremberg Code.is included. The case could be modified for use in non-majors and majors classes.  The format of the case challenges students of any background to use information from both science and ethics to see how the differing approaches of scientist and ethicist can complement and strengthen each other.

Technical details aside, Crispr-Cas9 makes it easy, cheap, and fast to move genes around-any genes, in any living thing, from bacteria to people. "These are monumental moments in the history of biomedical research," Baltimore says. "They don't happen every day." Using the three-year-old technique, researchers have already reversed mutations that cause blindness, stopped cancer cells from multiplying, and made cells impervious to the virus that causes AIDS. Agronomists have rendered wheat invulnerable to killer fungi like powdery mildew, hinting at engineered staple crops that can feed a population of 9 billion on an ever-warmer planet. Bioengineers have used Crispr to alter the DNA of yeast so that it consumes plant matter and excretes ethanol, promising an end to reliance on petrochemicals. Startups devoted to Crispr have launched. International pharmaceutical and agricultural companies have spun up Crispr R&D. Two of the most powerful universities in the US are engaged in a vicious war over the basic patent.

In the 1950s, Idaho sheep ranchers had a problem. About a quarter of their lambs were being born dead or deformed-sometimes with a single eye centered in the middle of their forehead, like the Cyclops of Greek legend, or missing their upper jaw. There were times when the pregnant ewes couldn't give birth at all, carrying the mutated fetuses until they were surgically delivered or the ewes themselves died. Unbeknownst to the farmers, the cause was a poisonous plant, western false hellebore (Veratrum californicum). Eventually, the plant would inspire a successful cancer therapy-but at the time, the sheep were what mattered.

The DNA in just one of your cells gets damaged tens of thousands of times per day. Because DNA provides the blueprint for the proteins your cells need to function, this damage can cause serious issues-including cancer. Fortunately, your cells have ways of fixing most of these problems, most of the time. Monica Menesini details the processes of DNA damage and repair.

Lying dormant in our genomes are millions of jumping genes. Originally discovered by Barbara McClintock, transposons are DNA sequences that can move from one location to another in our DNA. Transposons cause mutations when they jump to new locations, so keeping them from jumping is important. 

Through this method, the researchers were able to identify that the frizzled-6 gene was expressed around eight times more in tumor-forming cell lines. The specific cascade initiated by frizzled-6 and how it affects the development of cancerous cells has yet to be determined. The overexpression of frizzled-6 suggests that the protein either forms tumor cells directly or is an indirect result of other mutated pathways.

Science denial has real, societal consequences. Denial of the link between HIV and AIDS led to more than 330,000 premature deaths in South Africa. Denial of the link between smoking and cancer has caused millions of premature deaths. Thanks to vaccination denial, preventable diseases are making a comeback.

ranked by country

CRISPR still has a long way to go before it can be used safely and effectively to repair-not just disrupt-genes in people. That is particularly true for most diseases, such as muscular dystrophy and cystic fibrosis, which require correcting genes in a living person because if the cells were first removed and repaired then put back, too few would survive. And the need to treat cells inside the body means gene editing faces many of the same delivery challenges as gene transfer-researchers must devise efficient ways to get a working CRISPR into specific tissues in a person, for example. CRISPR also poses its own safety risks. Most often mentioned is that the Cas9 enzyme that CRISPR uses to cleave DNA at a specific location could also make cuts where it's not intended to, potentially causing cancer.

HPV is considered one of the most common sexually transmitted infections, and it affects both men and women! Is it dangerous, and can it be prevented? Get your official DNews t-shirt here: http://www.forhumanpeoples.com/collec... Read More: Genital HPV Infection - Fact Sheet http://www.cdc.gov/std/hpv/stdfact-hp... "Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States. Some health effects caused by HPV can be prevented with vaccines." Time To Rethink 'Girls-Only' Approach To HPV Vaccine? http://www.futurity.org/hpv-vaccines-... "Encouraging parents to have their sons get the human papillomavirus (HPV) vaccine-rather than just trying to get more girls vaccinated-could ultimately protect more people for the same price, according to a study by a mathematician."