March 17, 2016

A Bernese mountain dog; whether sensing low blood sugar or finding humans who are lost in the mountains, dogs use their sense of smell as an amazing tool. Credit: © Shutterstock

Doctors took notice recently when news agencies reported on a Los Angeles boy with diabetes. His life was saved by a nose – his dog’s nose! Even though many details are not fully understood, it is well-known that a dog’s amazing ability to sniff out certain scents could be a real lifesaver. Now, medical experts are starting to study how dogs’ amazing sense of smell may help to diagnose and support people with a variety of health conditions.

The life-saving Labrador retriever was specially trained to help a family monitor their son’s blood-sugar level by smell, and to then alert other members of the family when it became dangerously high or low. People with diabetes, a disease that disrupts the body’s ability to use a sugar called glucose, often need insulin pills or injections several times a day to maintain near-normal blood-glucose levels. But, among people with diabetes, hypoglycemia may occur if they get too much insulin. Hypoglycemia can cause brain damage and even death if it is severe and untreated. On a recent night, the boy experienced a dangerous drop in blood sugar as he slept. But the clever pooch was trained to alert the boy’s parents, who came to the rescue.

Smell is the dog’s superpower. With more than 40 times more scent receptors compared to humans, dogs can smell thousands of odors that the human nose is unable to detect. Some scientists believe the dog’s supreme sense of smell is so sensitive that it can detect tiny biochemical changes (changes caused by chemicals used by living beings, such as animals or plants) that occur in the human body. Some of these changes, such as in the level of certain hormones or other chemicals in the blood, are associated with certain diseases and disorders. In some studies, dogs have been trained to sniff out unique scents associated with several types of cancer in humans, including skin cancer, breast cancer, and bladder cancer. Other dogs are trained to recognize subtle clues to indicate a person is about to experience a seizure, due to epilepsy or other conditions. Several organizations in the United States and other countries are currently training dogs to recognize different scents and other clues related to a person’s health.

Scientists do not yet know exactly how some dogs seem to be able to detect changes in a person’s health. They have not identified any specific chemical changes that the dogs are picking up among the many biochemical compounds that change in health and disease. Some experts think that dogs may be picking up subtle visual cues associated with various health conditions. Domestic dogs have lived with people as pets for more than 10,000 years, longer than any other animal. Over thousands of generations, these naturally social animals have learned to pay close attention to body language and other clues in order to live happily and successfully with their families.

It is well-known that the companionship of a dog can contribute to a person’s general well-being. Scientific studies have shown that petting a dog slows the heart rate and lowers the blood pressure of the person who is doing the petting. In the future, your pet dog may become an important part of your overall healthcare.

Cats, the ball is now in your court!

December 31, 2013

A tiny, pink, wrinkly-faced rodent with outsized yellow teeth and an underground lifestyle has been named Vertebrate of the Year by the journal Science. The magazine’s editors said they choose the naked mole-rat because of two recent groundbreaking studies that helped to explain why the rodent has such a long lifespan and why it seems to be resistant to cancer.

Native to East Africa, naked mole-rats live in well-organized colonies in large burrows with many rooms. The rodents dig their burrows using their short, strong limbs, large claws, strong jaws, and big front teeth. The lips of the naked mole-rat close behind their teeth, so they can dig without getting soil in their mouth.

The naked mole-rat is a burrowing rodent of East Africa with wrinkled pink skin and sharp, chisellike front teeth. Naked mole-rats live in large colonies of up to 300 members, engaging in social behavior similar to that of ants and honey bees. (© Frans Lanting Studio/Alamy Images)

Naked mole-rats are one of only two kinds of eusocial mammals. (The other is the Damaraland mole-rat of sub-Saharan Africa). The eusocial naked mole-rats, like ants and bees, live in highly organized colonies ruled by a queen. Only the queen and several male colonists breed. In fact, the queen bullies nonbreeding females and males to prevent them from reproducing. The nonbreeding members of the colony care for the young, maintain tunnels, find food, and attack predators. Smaller, younger workers do most of the maintenance work. Larger, older individuals work together to drive off snakes, as well as naked mole-rats from other colonies. Sometimes, these protectors sacrifice themselves for the sake of the colony.

Naked mole-rats have attracted the attention of a number of researchers for two reasons: the rodents age much more slowly than mice of the same size, and they seem to be immune to cancer. Two studies published in 2013 helped explain these remarkable characteristics. In June, researchers from the University of Rochester in New York reported that naked mole-rats produce a supersized version of a molecule that helps to make the rodents’ skin more elastic. When the researchers removed the molecule from the rodents’ cells, the cells started to clump together and form tumors. Then in October, some of the same researchers reported that naked mole-rat cells seem to be able to build new proteins without making many errors. Scientists think that such errors contribute to the aging process.

Additional information:

To learn more about the naked mole-rat from the Smithsonian Museum, see

http://nationalzoo.si.edu/animals/smallmammals/fact-nakedmolerat.cfm

April 23, 2013

The United States Supreme Court recently heard arguments challenging the legality of  patenting genes. The case concerns patents granted to Myriad Genetics, a biotechnology company based in Salt Lake City,  for isolating two human genes–BRCA1 (breast cancer type 1 susceptibility protein) and BRCA2 (breast cancer type 2 susceptibility protein) in 1994 and 1995, respectively. Mutations in these genes increase the risk that a woman will develop certain types of cancers. The court’s decision could have a profound impact on medical and genetic research in the United States, affecting everything from the development of life-saving drugs and medical tests to genetically modified crops.

A patent is a document issued by a government granting an inventor exclusive rights to an invention for a limited time. The invention must be new, useful, original, and not easily discovered or created.

Chromosomes, made up of long strands of tightly coiled DNA, generally occur in pairs. This photograph shows 12 of the 23 pairs of chromosomes that occur in most human body cells. Copyright L. Willatt, Photo Researchers

Genes determine which characteristics living things inherit from their parents. One complete set of human genes is called a genome. Scientists have found that the human genome is made up of about 25,000 genes. Since 1982, patents have been granted in the United States for more than 4,000 human genes. A patent on a gene gives the company that discovered it exclusive rights to produce drugs, diagnostic tests, or other tools based on that gene.

Myriad Genetics was the first group to isolate the BRCA genes. They discovered that women who inherit mutations in the BRCA1 and BRCA2 genes have a significantly greater lifetime risk of developing breast and ovarian cancer than women who do not. Because Myriad holds a patent on these genes, doctors must purchase a blood test developed by Myriad to determine if a patient has the mutated version of either gene. Each test costs  about $3,000 dollars. In addition, the patent restricts other scientists from conducting their own research on BRCA genes.

The legal case against Myriad Genetics began in in 2009 when plaintiffs filed suit against the company. The plaintiffs in this case included researchers, patients and cancer survivors, breast cancer and women’s health groups, and scientific associations, all of which are being represented by the American Civil Liberties Union (ACLU) and the Public Patent Foundation. In 2010, a New York court ruled that the patents on the BRCA genes were invalid. Myriad Genetics appealed, and after several cases, the U.S. Court of Appeals ruled that human genes can be patented. This decision is now being appealed to the Supreme Court.

Attorneys for Myriad Genetics claim that companies should be allowed to own the discoveries they make through a patent. They claim that private companies will have no incentive to conduct important scientific research if they cannot profit from the results.

The plaintiffs argue that human genes are products of nature. Every cell in every person has copies of the BRCA genes. Under U.S. patent law, such products of nature may not be patented. The plaintiffs claim that such patents actually prevent useful scientific research because they restrict other scientists from conducting research on patented genes.

The Supreme Court’s decision on this case is expected in June 2013.

 Additional World Book articles:

• Gene (Special report-How Genes Cause Disease)
• Genome (Special report-What’s Next for the Human genome)