Category Archives: Disease

What is Metabolic Syndrome?

You might have heard the term “metabolic syndrome” and envisioned it as some sort of specific disease, but it’s not quite a “disease” in the typical sense. Metabolic syndrome is better described as a health state in which you are at an increased risk for conditions like diabetes, hypertension, and heart disease.

Metabolic syndrome has been defined in a few different ways. Here are a couple of different explanations:

Depending on how many metabolic risk factors you have, you could be classified as having “metabolic syndrome.” The four health states listed under the NCEP/ATP III definition can be considered as “risk factors” for metabolic syndrome. There are a lot of science-y words in that definition, so let’s break it down.

  • Central obesity: Fat accumulation in the abdominal area, which is particularly associated with obesity and its negative effect on health.
  • Dyslipidemia: Unhealthy levels of lipids (fat) in your body. This could either be too-low levels of “good” HDL cholesterol, too-high levels of “bad” cholesterol “LDL,” or too-high levels of triglycerides (TGs) – a type of fat saved as energy when your body can’t use all of the calories you’ve consumed.
  • Hypertension: It’s basically common knowledge that high blood pressure isn’t a good thing, but why is that again? When you have high blood pressure, it means your heart and arteries are working extra hard to pump blood through the body. Remember, blood carries nutrients and oxygen that all of your cells rely on to survive.
  • Insulin resistance: People develop type 2 diabetes when their cells form a resistance to insulin. Insulin is the hormone that facilitates the use of glucose for energy, so when cells aren’t responding to it, glucose levels in the blood increase. High blood glucose levels cause a myriad of problems, plus it means that your cells aren’t getting the glucose they need.

Mechanisms Behind Metabolic Syndrome

Metabolic changes leading to heart disease, diabetes, and hypertension don’t happen overnight. Lifestyle choices like diet and physical activity levels play a huge role in metabolic syndrome development, but some factors are unavoidable. For example, risk for metabolic syndrome increases with age.

Physiological changes in the body as a result of certain lifestyle choices like poor diet and low exercise levels lead to underlying, systemic inflammation, and oxidative stress. These metabolic changes are what ultimately lead to conditions like heart disease, diabetes, and hypertension.

Prevent or Manage

A healthy diet and active lifestyle can help prevent metabolic syndrome (and a lot of disease, really), but these qualities can also help manage metabolic syndrome if you’ve already started to develop it. Healthy food and physical activity support the liver and help your body better manage glucose.

For example, antioxidants found in micronutrients and phytonutrients like vitamin C, vitamin E, and beta-carotene can address oxidative stress. Antioxidants also promote healthy glucose metabolism and diabetes prevention, and they are associated with reduced risk of heart disease.

Ultimately, the solution here isn’t shocking. Eat healthy food. Be active. Reduce your risk of metabolic syndrome.

(*drops the spinach*)

Cancer Treatment Saves the Life of an HIV Patient – For the Second Time

I’m finally finding time to finish a blog post on the announcement Nature made earlier in March with a pretty big headline subject: for only the second time ever, an individual infected with HIV is “cured” – as much as it is humanly possible to be cured of HIV – via stem cell transplant.

University of Cambridge’s (UK) Ravindra Gupta, MD, led the study of this patient, whose name has not be released (I’ll use the term “2019 patient”). Researchers like Gupta actually warn against using the term “cured” to describe this person’s health status. So why are people (the media) saying that the 2019 patient is cured? Because the 2019 patient stopped taking antiretroviral drugs 18 months ago (16 months after receiving the stem cell transplant), and HIV has not returned.

Plus, the headline “person is cured of HIV” sounds a lot better than “person’s HIV’s levels have not returned after receiving stem cell transplant and halting antiretroviral treatment.” I won’t go on a tear about the issues with sensationalism in science journalism (right now, anyway).

The 2019 patient joins the ranks of Timothy Ray Brown, the ‘Berlin Patient,” who was “cured” in 2018 and still appears HIV free.

Berlin vs. London

Both Brown and the 2019 patient had a form of blood cancer that did not respond to chemotherapy, which prompted doctors to conduct a bone marrow transplant to replace diseased blood cells with healthy stem cells. These stem cells just so happened to also produce a very rare form of HIV-resistance. So these two patients came out of their procedure on their way to being both cancer-free and HIV-free.

In the case of the 2019 patient, doctors purposely chose a bone marrow donor who carried the HIV resistance trait – two copies of a mutation in a gene called CCR5. Experts estimate that just one percent of people of European descent carry the two-copy genetic mutation providing HIV resistance.

The CCR5 gene codes for a white blood cell receptor involved in the immune response to viral invaders like HIV. HIV binds the CCR5 receptor to attack white blood cells. So when CCR5 is not working normally due to a genetic mutation, HIV cannot attack white blood cells in the same way.

Before Brown received his stem cell transplant a decade ago, doctors tried aggressive chemotherapy and radiotherapy to treat his cancer. For the 2019 patient, doctors chose a less aggressive approach consisting of chemotherapy and drugs. Experts from the study acknowledge the difference in treatments as a sign that stem cell transplantation as a treatment for HIV infection does not require aggressive treatments to be effective.

Why only two?

So why not make stem cell transplant a standard procedure to treat HIV infection? The procedure is risky, more so than just continuing to suppress HIV with a daily drug regimen. The transplant could fail, or it could result in a lethal autoimmune attack. Other potential consequences include organ damage, respiratory distress, fluid overload, infection, and low platelets and red blood cells. Plus, HIV infection makes everything more dangerous.

Although stem cell transplants won’t quite work as a catch-all treatment for anyone infected with HIV, the basic concept behind the success of both patients “cured” of HIV yields promise. In laboratories all over the world, scientists are likely hard at work developing gene therapies targeting CCR5.

HIV/AIDS Basics

HIV (human immunodeficiency virus) is the virus – the “microbial agent” – that causes AIDS (acquired immunodeficiency syndrome) – the “disease – just like rhinovirus (“microbial agent”) causes the common cold (“disease”). HIV is a particularly devastating virus because it attacks the very cells employed by the human body to defend itself: CD4 immune cells.

Antiretroviral therapy (ART) does not lead to a cure, but it does improve quality of life and reduce the risk of an HIV-positive person passing the infection to someone else. ART accomplishes both tasks by preventing HIV from multiplying – minimizing the amount of virus in an infected person’s blood and preventing a person with an HIV infection from becoming a person with AIDS.

“It takes two to make a thing go right; It takes two to make it outta sight”
A commentary by Science Kara

Now that two people have been “cured” of HIV via the same means, I can’t image that it will be too long before researchers are publishing new studies on CCR5 gene therapy, conducting studies in vitro, in mice, and in chimpanzees. It will be a while until there are studies done with humans (per usual in science), but I don’t think it will be another 11 years before there is another major breakthrough in treatments for HIV more conclusive than ART.

In the midst of all the news reporting on the 2019 patient earlier this month, my favorite piece was from The Daily podcast and host Michael Barbaro from the New York Times. Barbaro goes beyond the science of the matter that I’ve discussed here and talks about the history of the HIV epidemic to truly represent how significant it is to declare the second “cure” of an individual infected with HIV.

References

Matthew Warren’s “Second patient free of HIV after stem-cell therapy.” published online as news for the journal Nature on March 5, 2019.

The National Institutes of Health website “AIDSinfo.”

Johns Hopkins Medicine

Autoimmune Disorders and Gluten Intolerance

Some medical conditions require a patient to eliminate gluten from their diet.

Celiac disease, which affects about 1% of the population of the United States (Mayo Clinic), is an autoimmune disorder based on an intolerance of gluten proteins. Autoimmune disorders occur when the immune system attacks particles that are normally not harmful to the body, either ingested food proteins or the body’s own cells.

Celiac disease occurs when the immune system attacks the body’s own cells after gluten is ingested. Specifically, the cells of the small intestine are targeted. Celiac disease-related attacks on the small intestine damage the cells that absorb nutrients during digestion (Celiac Disease Foundation).

Celiac disease is hereditary, meaning it runs in families. The pattern of inheritance is unknown (NIH). However, 95% of people with celiac disease have the same gene specific for celiac disease predisposition (Medscape, Genetics of Celiac Disease).

Rheumatoid arthritis is another autoimmune disorder relating to gluten intolerance. However, gluten is only one of many potential signals that can lead to an autoimmune attack. Rheumatoid arthritis causes inflammation of the joints – resulting in swelling, pain, and decreased movement ability (Arthritis Foundation).

Bailey Brislin, a UNC-Chapel Hill sophomore biology major preparing for medical school, was diagnosed with juvenile rheumatoid arthritis during her first year in high school. “My ankle had been swollen for months. We went to multiple doctors that couldn’t tell me what was wrong,” Brislin recalls of the time before her diagnosis. Finally, an ankle specialist ordered an MRI and referred Brislin to a rheumatologist after blood test results indicated Rheumatoid factor (RF) in her system. RF is an antibody characteristic of rheumatoid arthritis patients as well as people with other autoimmune disorders (Medscape, Rheumatoid Factor).

The next step to calculating Brislin’s proper treatment was a 5-week series of food sensitivity testing. Although the cause of rheumatoid arthritis is not fully known, potential factors triggering joint inflammation are food proteins, pathogens, female hormones, obesity, stress, and other environmental factors (Arthritis Foundation).

The results of Brislin’s sensitivity tests showed intolerance of gluten and dairy: typical occurrences among rheumatoid arthritis patients. After a while, Brislin realized that eliminating gluten from her diet had a much stronger impact on reducing  her joint inflammation than eliminating dairy.

“After a month off of gluten, I felt better. I was able to stop taking pain medication just by eliminating gluten alone,” Brislin says, “but I should be dairy-free too.” Many years later, Brislin still regularly takes immunosuppressant drugs to improve her condition.

After many years of maintaining a gluten-free diet to ensure her joint inflammation does not return, Brislin has also gathered an opinion on the growing trend of a gluten-free diet. Brislin compares people going gluten-free for no necessary reason to people trying a vegetarian diet just to see if they can do it. “There are people glorifying the gluten-free diet. It’s just bread,” Brislin says, in response to people going gluten-free for supposed “just to be healthy” reasons.

“So gluten-free becomes this very popular trend… and I get all of this criticism for being gluten-free. My rheumatologist always talks about how you don’t have to find the specific scientific data you want, just work with what has been proven in your own case,” Brislin says as she describes her encounters with gluten-free skeptics. Brislin experienced the growth of the gluten-free trend from a very unique perspective. She understands the necessity of eliminating gluten from the diet in certain circumstances but is also critical of the diet in other instances.

Her evaluation below perfectly sums up my goal in writing this series on the growing obsession with gluten:

“There are a lot of people who are very healthy who also eat gluten. I don’t think there’s anything inherently wrong with gluten – it’s not an evil food. Not eating a lot of bread is probably a good thing, but stopping eating bread and replacing it with gluten-free bread doesn’t make much sense… I’m not sure what dietary benefits people think that’s providing…”

Stay tuned for my third and last segment of my series on the gluten-free trend. This last post will contain further analysis on the development of the gluten-free trend, data from a poll of opinions about it, and an interview with Raleigh allergist Dr. Vaishali Mankad.

What’s the deal with gluten?

In the last decade, the presence of “gluten-free” products has drastically increased on our grocery store shelves, TV commercials, and in our conversations. “She’s gluten free now” is a statement we hear often while catching up with friends. Why is gluten all of a sudden such a problem? What IS gluten? Should everyone eliminate gluten from their diet? All of these questions and more will soon be answered in a 3-part series of blog posts about gluten and the recently popular gluten-free diet trend. I plan to describe gluten and the foods it is naturally found in and also discuss the nature of gluten-free substitutes. Plus, look forward to exclusive interviews with UNC Chapel Hill student, Bailey Brislin, as she explains why she follows a gluten-free diet, and Dr. Vaishali Mankad, a practicing allergist at Allergy Partners of Raleigh.

Understanding the biology surrounding gluten as well as its impact on our health is important. We are constantly in search of the best diet to follow for optimal health, and the media has a huge impact on what we think will help us lose weight or be healthier.

Is eliminating gluten from your diet the right choice for you? Stay tuned to find out! 

Rise of the Planet of the Apes — A Scientific Critique

“Rise of the Planet of the Apes” told the story of a researcher who, while looking for the cure to Alzheimer’s, inadvertently created an army of highly intelligent primates (whoops) by developing a virus that allowed brain tissue to heal itself. The scientist, played by James Franco, had personal reasons for developing the cure; his father, living with him at home, was visibly suffering from Alzheimer’s.

Throughout the film, many of the details involving the miracle virus are vaguely expressed, but the film does adequately show a difference in how the chimpanzees and humans are differentially affected by the virus when infected. Thus, this film is a fine representation of the difficulties of applying animal model research in the lab. Moreover, this film uses topical knowledge of the pathogenicity of Alzheimer’s combined with the more widespread knowledge of the visible, debilitating effects of the disease to develop a dramatic science-fiction story with just enough realistic explanation of scientific phenomena to make the story seem plausible in real life.

Alzheimer’s disease is a neurodegenerative disorder occurring in nearly 5% of the elderly population worldwide (Bali et. al, 2010). The disease develops over time as neuron cells die, and ultimately presents clinically with memory loss and cognitive impairment (Castellani et. al, 2010). Current studies in Alzheimer’s therapy revolve around prevention: recognizing particularly susceptible groups and taking steps to slow the onset of the disease. Specifically, amyloid-β treatments are utilized since deposits of these peptides are often visible many years before patients show symptoms of Alzheimer’s (Reiman 2013).

James Franco and his scientist buddies, while looking for a cure to Alzheimer’s, infect chimpanzees with an experimental virus to examine how it impacts brain tissue and intelligence. Promising results show infected chimps succeeding at the so-called “Lucas Tower” – an actual laboratory test called the Tower of Hanoi. This test is used in real life in various studies, and it measures cognitive abilities based on skill learning and mastery (Schiff and Vakil, 2015). In the film, improved intelligence (based on a “good” Lucas Tower score) of the chimps is understood to supposedly highlight potential brain-healing qualities of the drug in humans. However, this mechanism is not particularly explained, just assumed. My critique of this particular detail is this: although new brain cells may develop in chimps infected with the drug and subsequently enable them to perform higher level functions, there is no assurance that this same mechanism will revitalize dead neurons in a human brain plagued with Alzheimer’s.

The scientist’s father shows the accurate signs of Alzheimer’s. He has trouble using silverware while eating, remembering piano tunes, and he is unable to drive. Complications occur in the lab, and the scientist eventually finds himself running unofficial, experimental human trials on his father using the virus. The Alzheimer’s-stricken old man receives an injection before bed and is heard flawlessly playing old piano tunes just a couple of hours later after waking up. Although there is no current complete cure to Alzheimer’s in existence to compare this phenomena to, it is still hard to believe that such a monumental improvement would occur within the man’s brain overnight with such visible effects. Alas, the quick change certainly instills a strong feeling of fulfillment and human victory over misfortune amongst the film’s audience.

In addition after the lab complications, the scientist takes home a baby chimpanzee (Caesar) that is found to have received the virus in utero, his mother being one of the chimps showing increased intelligence after infection with the virus. Although some viruses like HIV and herpes are known to cross the placenta during pregnancy or transmitted during birth, the movie did not provide enough detail about the virus to be able to say whether this transmission would be plausible or not. As the scientist’s father responds to the virus with restored cognitive abilities, the chimp responds to its presence in his body by showing abnormal, high-intelligence behaviors for a monkey: quick learning of sign language, humanistic qualities like holding and drinking from cups, and general adaption to a human environment.

Although the chimp continues to get smarter (and cause more problems), after a while the old man regresses back to showing symptoms of Alzheimer’s. The scientist associates this problem to his father’s immune system producing antibodies against the anti-Alzheimer’s virus. It is unclear in the film how long the virus is effective before the body responds by attacking it. It seems like in order for an immune response to be plausible it would have had to occur within a few days of the man receiving the virus. Another discrepancy is this: another scientist in the lab is accidentally exposed to the virus during a chimp experiment and dies. The infection causes some hemorrhagic disorder that was clearly not present in the old man (although he ends up dying as well since the virus stops being able to cure his Alzheimer’s). Lastly, the chimp infected with the virus neither develops the hemorrhagic disorder nor builds up antibodies against the virus. These discrepancies are strangely not addressed and slightly frustrating to someone with a scientific mind.

Despite the vague details of some biological aspects and the mentioned inconsistencies, the foundation of Alzheimer’s as the scientist’s initial motivation for most of the drama that occurs is powerful and relatable. As the generation of senior citizens increases, there a larger high-risk group for Alzheimer’s, and many people my age and older are likely to experience their grandparents or parents suffering from this unfortunate disease.

The next time you watch a science-fiction movie consider the plausibility of the science discussed in the plot. The majority of science-fiction films you will watch won’t have any scientific basis at all, but one of the coolest parts of this film is that a biologist like myself, however visionary, can see a future in brain-healing Alzheimer’s therapy. I am less convinced that vengeful apes will congregate, learn to speak and take over the world, but… I digress.

Check out the Rise of the Planet of the Apes trailer here:

Note: I originally wrote this review for my Molecular Basis of Disease class at UNC.

References

  1. Bali, Jitin; Halima, Saoussen; Felmy, BoasView Profile; Goodger, Zoe; Zurbriggen, SebastianView Profile; et al. Cellular basis of Alzheimer’s disease. Annals of Indian Academy of Neurology, suppl. Suppl 213 (Dec 2010): 89-93.
  2. Castellani, Rudy J.; Rolston, Raj K.; Smith, Mark A. September 2010. Alzheimer’s Disease. Disease-a-Month. 56(9): 484-546.
  3. Reiman, Eric M. January 2014. Alzheimer’s disease and other dementias: advances in 2013. The Lancet Neurology. 13(1): 3-5.
  4. Schiff, Rachel; Vakil, Eli. 2015. Age differences in cognitive skill learning, retention and transfer: The case of the Tower of Hanoi Puzzle. Learning and Individual Differences. Accessed Online.
  5. Picture Link: http://www.dvd-ppt-slideshow.com/blog/wp-content/uploads/2011/08/rise-of-planet-of-the-apes-4.jpg