In honor of St. Patrick’s Day today, I thought we’d talk about snakes today. Vertebrates defend themselves from infections with the help of the adaptive and innate immune systems. The first responder to an infection is typically the innate immune system, which is not specific to a particular pathogen. This system helps to prevent the infection from spreading and uses various toxins to kill pathogens. The adaptive immune response, on […]
I read an interesting review article explaining how cells evolved the ability to kill off pathogens and, in turn, how pathogens evade death. It is kind of like a perpetual game of ‘cat and mouse’ in which the interaction between animals and pathogens drives the evolution of host defenses against infections while at the same time driving the evolution of pathogen strategies to avoid detection. According to the review article, […]
Researchers at the University of New South Wales (UNSW), Sydney discovered a ‘jumping gene’ that prevents the immune system of mice from overreacting to a viral infection. Jumping genes are movable nucleic acids, or transposable elements, that make up nearly 2/3 of the genome in mammals. They help regulate the expression of genes. Some transposable elements in the genome are new and some originated in ancient times. In the new […]
Neutrophils are specialized immune cells that becomes activated in response to foreign particles or microorganisms. Think of them like security guards in your body. As they travel through the blood, their job is to detect and get rid of invading microorganisms. They also help spark inflammation responses to infections. For these reasons, they are known to help maintain homeostasis in the body, but they can also play roles in disease […]
Polar bears (Ursus maritimus) living near the southern Beaufort Sea are spending more time on land during the summer months than in years past as a result of climate change and melting sea ice. Researchers wanted to know whether bears that spent more time on land were exposed to more pathogens compared to those who spent more time on sea ice. Their results, published in the journal Physiological and Biochemical Zoology, showed […]
As you may already know, bone marrow contains cells that specialize in both bone as well as blood maintenance. Stem cells destined to become white blood cells, red blood cells and platelets are called hematopoietic stem cells (aka: HSCs). CXCL12 is a special ligand that helps keep HSCs in the bone marrow by acting as a chemical attractant for the chemokine receptor C-X-C (CXCR4) found on HSCs. Some researchers are […]
Several of the posters and talks at the Experimental Biology meeting in San Diego focused on Weddell Seals. They are not only cute, they are really interesting physiologically. Emma Weitzner, a graduate student in the lab of Dr. Heather Liwanag, presented a poster on Weddell seals, which are studied as models of the physiology of diving. Emma and her team recorded diving behavior and collected blood samples from 1 week-old […]
Camelids (think llamas, alpacas and of course, camels) produce rather special antibodies that are highly sought after for research and biomedical applications. Nanobodies are small fragments of camelid antibodies that retain the ability to identify specific proteins. Because they are so small, they can bind to segments of proteins that intact or larger antibodies are unable to contact. This is what makes them attractive candidates in the search for new […]
Platypuses are rather bizarre mammals. For one, they lay eggs and although they feed their young milk, they sweat this milk from glands on their belly. Because the young lap up the milk and they live in burrows, they are exposed to microbes at a very young age. Like many mammals, platypus milk has antibiotic properties to help protect the young. However, the antibiotic protein found in platypus milk appears […]
Okay, I realize this is not a comparative physiology topic. But after reading this article, I just had to share it. A new study published in American Journal of Physiology – Gastrointestinal and Liver Physiology presented data suggesting that parasitic worms may help treat or even prevent inflammatory bowl disease (IBD) in children. IBD is a condition characterized by inflammation in the gut that can lead to symptoms such as diarrhea […]
Life Lines by Dr. Dolittle 