The heart is an incredible muscle. Unlike the brain where a person can continue to be “alive” without any electrical activity, without a heartbeat, a person cannot live. The average person doesn’t ever think about how or why their hearts lub dub every minute of every day until they die. For someone whose heart doesn’t beat properly, the lub dub is a frequent worry. Brandon England is one of those people. He was diagnosed with dilated cardiomyopathy putting him at risk for dangerous arrhythmias that could be fatal if not corrected quickly.
He was implanted with an internal cardiac defibrillator, ICD for short, to help stop those arrhythmias almost instantaneously. Typically ICD’s need to have a direct connection to the heart to detect the heart’s rhythm. Those connections are called leads. Brandon’s IDC is different though. Its wireless and doesn’t require those leads that go to the heart. It’s the first of its kind to be implanted in Utah and will hopefully continue to be used to help prevent sudden cardiac arrest.
I’ve worked in a cardiac unit for the past three years and have been trained in identifying the various rhythms that the heart can have. In my training, I have learned that there are chemical reasons why the heart will behave in certain ways. The body needs to have a balance of electrolytes (substances that can conduct electricity) to function properly.
This is especially important in the heart. Sodium is needed for the generation of electrical signals vital for movement. The heartbeat is generated through electrical impulses that tell the muscle to contract and relax. People that are in heart failure (and are often recipients of ICD’s) sometimes will get what is called fluid overloaded.
That fluid overload can happen when sodium levels become too low and fluid accumulates in the limbs, around the lungs and even the heart because the heart is pumping ineffectively. Potassium is another electrolyte that is vital for a properly functioning heart. Potassium is the major cation in the body. If potassium levels get too low, the heart can convert in ventricular tachycardia, or even worse, ventricular fibrillation. Neither of those rhythms are compatible with life and need immediate correction through either chest compressions or defibrillation, thus the purpose of an ICD.
The ICD works in the same way as an external defibrillator by delivering a shock to the heart, hopefully returning it to a normal sinus rhythm. Low levels of magnesium can also lead to these dangerous and chaotic rhythms. Maintaining proper levels of these electrolytes are vital to a healthy heart. Antibiotic Use in Farm Animals In the late 1920’s, a bacteriologist by the name of Alexander Fleming noticed that bacteria he had been growing on a culture plate had been negatively affected by a mold that had contaminated the sample called penicillium notatum.
After many years of research, in 1941 penicillin was introduced worldwide as an antibiotic to treat bacterial infections. It was discovered that penicillin did not treat all types of bacterial infections, so other antibiotics were developed to treat an array of illnesses. Antibiotics work by inhibiting enzymes and proteins in bacterium. Antibiotics have been a great gift to humanity through treating infections and illnesses, but bacteria is quite adaptive and can develop resistance to the very drugs created to destroy them.
Around the same time antibiotics were being used to treat human illnesses, it was introduced into the farm setting through feed and water of animals prophylactically to prevent the spread of sickness in a close confines and to encourage the growth rate of the livestock. In the 1970’s, the Food and Drug Administration became involved in usage of antibiotics in livestock over concerns of the drugs being overused and the problems that those drugs posed to the humans who would be consuming the products from those animals.
It was found that the use of penicillins and tetracyclines in animal feed was unsafe as that those two medications are often used in humans, therefore increasing the risk of resistance. Findings by the Natural Resources Defense Council (NRDC) have shown that the practice of using penicillins and tetracyclines in feed was never stopped, though. Their findings also showed that there are many high risk antibiotics that are still being used today. Antibiotic resistance is the result of biochemical alterations that change the cell itself.
The bacterial cell modifies itself so it is either protected from the antibiotic through cell wall proteins or by the creation of a pump that removes the antibiotic, rendering the drug useless in the treatment of the bacteria. Because a bacterial cell is incredibly simple, it is easy for it to replicate and mutate. These mutations are now a new bacterium entirely, and one that is better equipped to resist the antibiotic that is trying to destroy that very bacterium.
The resistance of antibiotics is a serious problem that is difficult to treat. It almost seems like it can lead to an endless, vicious cycle where one antibiotic after another is used each in increasing potency against an aggressive, adaptable invader. While antibiotics given to livestock don’t account for all the reasons why humans become antibiotic resistant, they seem to be a contributing factor. HIV Returns in Two Patients after Bone Marrow Transplants In 2012, two HIV positive patients had received bone marrow transplants to treat their lymphoma.
Neither patient was looking for a cure to their HIV with the transplants, but a treatment for the cancer they had acquired secondary to the virus. Although, it seemed that with the bone marrow transplant they were cured of the virus thought to be incurable. The two men had blood tests taken every 7-10 days to test for detectable levels of HIV in their system and after 6 months, it was undetectable.
Seeming like a miracle and a medical breakthrough, the men were “functionally cured” and stopped taking their antiretroviral medications that suppressed the virus. Unfortunately for the men, after some time of not taking their medications the virus was found again in their blood. While this seems very upsetting, it is a big step in the right direction for HIV research, giving researchers somewhere to go with searching for a cure for everyone affected by this terrible disease.
The human immunodeficiency virus and the treatment of this virus is one example of chemical biology. HIV attacks the body’s natural immune system by destroying the T cells, which are responsible for activating the immune system. T cells have a special protein that binds to antigens (anything that the body finds that is foreign and needs to be eliminated), which activated the cells ability to destroy that antigen. However, those same proteins that are so important for signaling the body that something is wrong and needs to be removed are receptors for HIV. When HIV attaches to these proteins, it now knows that cell’s biochemical machinery.
It then uses that information to cause the body to attack its own immune system, leaving one defenseless against minor illnesses that a normal, healthy immune system could take care of. This is where the medications used to suppress HIV come into play. Many of these drugs are inhibitors, blocking the enzyme-substrate chemical bond. These drugs can treat patients affected by HIV, giving their immune systems a much needed boost, but are only a treatment not a cure.
The thing that I found intriguing about this case is that the two patients who had received the bone marrow transplants seemed to be cured for a time being. When a patient is given a bone marrow transplant, it’s often after that patient has already been treated with chemotherapy. Chemotherapy does its job by destroying cancer cells, but is unable to differentiate between normal cells and the cancerous ones so all of the cells are killed regardless of if they were bad or good. As a result of the chemotherapy treatment, when one is the recipient of a bone marrow transplant with new, immature cells the bone marrow is now able to continue to create healthy cells that are cancer free.
Perhaps because the sick cells were replaced with healthy cells in the HIV patients and they were still taking their antiretroviral medications, they were preventing the virus to manifest again. Low Oxygen Levels May Lead to Cancer Treatment Oxygen is probably the most important level to all life on earth. It is the most abundant element not only in humans, it also ranks as most abundant in the earth’s crust and atmosphere. It’s also the most important thing a person needs to survive. While we all need food and water to live, it is possible to go a few days without water and even weeks without food (although neither
is recommended if it can be avoided), one can only survive for a few minutes without major cellular damage leading to brain death or eventually whole body death. When the body does not get enough oxygen for long periods of time, it will become hypoxic. Hypoxia can be generalized, affecting the whole body or localized, only affecting one location or area. For such large areas this can create major problems systemically. Ideal levels for oxygen saturation in the blood is 90% or higher. Most healthy individuals have no problems maintaining these levels on their own with “room air” and those who are not able to can use
supplemental oxygen to keep their levels at acceptable levels. For people who do not receive needed oxygen, they can develop ischemia which is caused by restricted blood flow. Interestingly, cancer cells and tumors don’t react like other areas of the body when they become hypoxic. In fact, cancer cells are chronically hypoxic because those cells divide at such a rate that the oxygen flow that is available is inadequate to compete with the growth rate. Cell biologists recreated an environment similar to what cancer cells are used to being in in order to better understand the function of those cells.
The researchers deprived the cells of oxygen and recorded their behavior. It almost seems alien that where all animals and humans are dependent on oxygen to survive, cancer cells seem to thrive in anoxic surroundings. By studying this behavior, it gives scientists more insight and information that can be used in conjunction with data that has already been collected to create more effective treatments for cancer. With hope, these circumstances that occur in cancerous cells and their deoxygenated environment, scientists and researchers can make another step towards the elimination on cancer all together.