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Some thyroid 101 background: Your thyroid gland is the butterfly-shaped gland at the base of your neck that secretes two all-important hormones that control major bodily functions (including how you use energy, regulate body temperature, and digest food) and organs (including the heart, brain, liver, kidneys and skin). But with hypothyroidism, your body can have normal to low thyroxine hormone levels and elevated thyroid stimulating hormone (TSH) levels. These high TSH levels are a result of an overworked pituitary gland that is trying to elevate the hormone levels in an inadequately responsive thyroid.

Scientists have discovered a new hormone that fights the weight gain caused by a high-fat Western diet and normalizes the metabolism -- effects commonly associated with exercising. When tested in mice, the hormone blocked the negative health effects of eating a high-fat diet.

Researchers have long known that women whose families include fraternal twins are more likely to give birth to twins themselves, and they're finally starting to figure out why. After scanning data from nearly 2000 mothers of fraternal twins, scientists from eight countries found two genes that increase a woman's chance of having twins-one that affects hormone levels and another that may alter how ovaries respond to them. The second of these may also have implications for why some women respond better than others to in vitro fertilization.

If you think of your dog as your "fur baby," science has your back. New research shows that when our canine pals stare into our eyes, they activate the same hormonal response that bonds us to human infants. The study-the first to show this hormonal bonding effect between humans and another species-may help explain how dogs became our companions thousands of years ago.

Like many newborn mammals, baby mice cry to get their mother's attention. But the mother doesn't instinctively recognize these calls; she must learn the sounds of her offspring-just as human parents must learn the cries of their infants. Now, a team of researchers has discovered that the hormone oxytocin, which has been tied to trust and maternal bonding, holds the key to how this learning occurs. Only after oxytocin  tweaks the brain of a female mouse does she respond with a mother's concern and attentiveness to crying pups.

The team, led by senior authors Qi Zhou and Xiao-Yang Zhao, both from the Institute of Zoology at the Chinese Academy of Sciences, took embryonic stem cells from mice and treated them to a series of carefully worked out steps that included first exposing the stem cells to testicular cells in newly born male mice. The scientists then recreated the chemical environment that sperm cells need to grow, including early development factors and sex hormones including testosterone, follicle stimulating hormone and a growth factor from the pituitary gland.

A kind of salmon that's been genetically modified so that it grows faster may be on the way to a supermarket near you. The Food and Drug Administration approved the fish on Thursday - a decision that environmental and food-safety groups are vowing to fight. This new kind of fast-growing salmon was actually created 25 years ago by Massachusetts-based AquaBounty Technologies. A new gene was inserted into fertilized salmon eggs - it boosted production of a fish growth hormone. The result: a fish that grows twice as fast as its conventional, farm-raised counterpart.

This animation describes insulin resistance, an underlying cause of type 2 diabetes. It explains the roles of glucose and the hormone insulin in our body. Symptoms of diabetes are reviewed and various health complications that type 2 diabetes can lead to if left untreated.

In this interrupted case study, students shadow an endocrinologist as she tries to determine what is wrong with Angela Barber. Angela is a middle-aged woman presenting with symptoms suggestive of a thyroid issue. Students are given background information, patient history, and results from thyroid-specific blood tests. The exercise emphasizes the hypothalamic-pituitary-thyroid axis and particularly highlights the role of negative feedback. Students will use results from serum thyrotropin and thyroid hormone level tests, as well as patient symptoms, to come up with a diagnosis. In preparation for the diagnosis, students are asked to compare the endocrine profiles of patients with Graves' disease, Hashimoto's disease, iodine deficiency (primary hypothyroidism), and various tumors. The case was developed for college-level biology majors in a physiology course, but also has been used successfully for pre-nursing students in a non-majors anatomy and physiology course. Thus, this activity would be suitable for majors in physiology or pre-medical students, as well as allied health majors.

This case study was developed for an introductory biology course with the goal of integrating content (specifically, structure/function, signaling pathways, and homeostasis) while reinforcing general critical thinking skills and the scientific method (generating hypotheses, evaluating evidence, and making predictions). The case is suitable for a flipped classroom and there are several videos associated with it. The case revolves around an obese two-and-a-half-year-old boy who won't stop eating. Students become familiar with some basic concepts related to obesity and leptin signaling through the videos that they watch before class. They then use class time to work through the case (delivered as an interactive slide show, including several clicker questions) to determine the genetic basis for this child's obesity and possible therapies to manage his weight. The case could also be adapted and expanded to be used in a physiology course to explore the interaction of various hormones that regulate appetite and metabolic rate or in a cell biology class to explore JAK-STAT signaling.

For Collinge, this led to a worrying conclusion: that the plaques might have been transmitted, alongside the prions, in the injections of growth hormone-the first evidence that Alzheimer's could be transmitted from one person to another. If true, that could have far-reaching implications: the possibility that 'seeds' of the amyloid-β protein involved in Alzheimer's could be transferred during other procedures in which fluid or tissues from one person are introduced into another, such as blood transfusions, organ transplants and other common medical procedures.

"When you are diabetic, you have to check your blood sugar levels. The doctor tells you to do it four times a day. So you prick your finger. A tiny drop of blood appears. You put it on the tester and within five seconds you get the result," says Timothée, who suffers from diabetes. Normally, it's the job of the pancreas to control the levels of sugar in the blood by producing a hormone called insulin.

2 min video A quick tutorial, showing how we use restriction enzymes to cut out a desired gene from one organism, and insert it into the plasmid of a bacterium. This allows massive production of the desired protein (in this case the hormone: insulin) in a relatively short amount of time.

What an incredible transformation. A protein used to help bones mend can also force pancreatic cells into producing insulin. The discovery could help people with type 1 diabetes produce their own insulin without having to take daily injections. In type 1 diabetes, beta cells in the pancreas that make insulin - the hormone that keeps our blood glucose levels at a safe concentration - are destroyed by the immune system. As a result, people with the disease have to inject themselves daily with insulin. Now, researchers have discovered that non-beta cells in the pancreas can be transformed into insulin-producing cells, merely by exposing them to a growth factor called BMP-7.

This "clicker case" tells the story of "Hannah," a baby girl adopted by two loving parents who grows up with an uncontrolled appetite and develops severe early-onset obesity. Students follow Hannah's story as she develops excessive eating early in life, which her health care team is unable to explain. A visit to obesity specialists finally reveals the underlying cause of Hannah's obsession with food: extremely low levels of circulating leptin, a hormone that regulates appetite and body weight. It is further discovered that Hannah's leptin deficiency is due to a mutation in the LEP gene. As the story unfolds, students first work on unit conversions and BMI calculations to practice quantitative skills as well as graph and data interpretation skills. Students then apply their knowledge of DNA transcription, translation, and protein structure to answer questions based on figures from a 2019 study on LEP mutations. The case is best suited for high school and lower-level undergraduate biology courses.

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Nestled in the tissues of your neck is a small, unassuming organ that wields enormous power over your body: the thyroid. Emma Bryce explains how the thyroid, like the operations manager in a company, is tasked with making sure that all the cells in your body are working properly.

Series of review handouts from Living Systems Regents course