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Showing posts from November, 2017

Adult-onset Huntington's Disease, second Post

Huntington’s Disease is a genetic disorder that causes the progressive breakdown of nerve cells in the brain. It well known for causing uncontrolled movement, emotional problems, and loss of cognition. HD is caused by a mutation in the mhTT gene on chromosome 4. This gene gives instructions for making a protein called Huntingtin. The exact function of this protein is unclear, but it is believed that this protein is important to nerve cells in the brain. The mutation in the mhTT gene that leads to HD involves a DNA segment known as a CAG trinucleotide repeat. The CAG segment in a normal HTT gene repeats 10 to 35 times. In people with HD, it repeats from 36 to over 120 times. The excessive repetition of this DNA segment results in a larger form of the Huntingtin protein. HD is referred to as the quintessential family disease because every child of a parent with HD has a 50/50 chance of caring the faulty gene. This is because HD is inherited in an autosomal dominant manner. Theref

Tay-Sachs disease

This week id like id like to talk about a genetic disorder called Tay-Sachs Disease.   Tay-Sachs disease is a rare genetic disorder that progressively destroys nerve cells referred to as neurons in the brain and spinal cord. Tay-Sachs disease is caused by a mutation in the HEXA gene. The HEXA gene provides instructions for making part of an enzyme called beta-hexosaminidase A which plays a significant role in the spinal cord and brain. Mutations in the HEXA gene disrupts the activity of beta-hexosaminidase A which the prevents the enzyme from breaking down GM2 ganglioside. This results in an accumulation of GM2 ganglioside in the neurons of the brain and spinal cord. The progressive buildup of GM2 ganglioside leads to the mass destruction of these neurons causing the various symptoms of Tay-Sachs syndrome. The most common form of Tay-Sachs disease becomes apparent in infancy. Infants who acquire this disorder usually appear to be normal until they reach the age of 3-6 months. W

Phantom Limb Pains, second post

There are several complications that people who have below knee amputations (BKA) and below elbow amputations (BEA) must live with. One of the most common complications is referred to as phantom sensations or phantom limb pains. When an individual experiences Phantom limb pains (PLP), they experience ongoing painful sensations that seem to be coming from the limb that has be previously amputated. PLP are experienced by 80% of all individuals who have had a limb amputated. Phantom limb pains are most commonly felt in the arms or legs, but they have reportedly been felt in other parts of the body that have been previously amputated, such as the breast. What causes phantom limb pain is not entirely known. Many experts believe that phantom pain may be partially explained as a response to mixed signals from the brain. After an amputation, areas of the spinal cord and brain lose input from the missing limb and adjust to this loss of attachment in unpredictable ways. The result can tri

Parasitic Twinning

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Parasitic twins are combined identical twins in which the tissues of a severely defective twin (referred to as the parasitic twin) are dependent on the cardiovascular system of the other fully intact twin (referred to as the autositic twin) for survival. Parasitic twins occur when a twin embryo begins developing in utero but the pair does not fully separate and one embryo maintains dominant development at the expense of its twin sibling. The underdeveloped twin which is considered the parasite, is incompletely formed making it fully dependent of the body functions of the autositic twin. In majority of the cases that are seen, the phenotype that is displayed is one normal functioning individual with additional appendages or organs. Recently, there have been questions on whether or not these additional appendages are in fact another person or just a genetic mutation of the host’s body. The autositic twin tends to experience several complications as a result of fulfilling the

Hemodialysis, second post

Hemodialysis is a medical process that individuals who have chronic kidney disease, and acute kidney injuries must undergo routinely. For those of you who do not know, the main functions of the kidneys are to extract waste from blood, balance body fluids, form urine, and aid in other important functions of the body. When an individual has renal failure, their kidneys can no longer function properly. So, when a kidney can no longer fulfil it is duty, a man-made membrane referred to as a dialyzer steps up to the plate and gets the job done. The dialyzer removes waste such as urea from the blood, it restores balance of electrolytes in the blood, and it eliminates extra fluid from the body.   So, the way hemodialysis works is by connecting an individual to a filter (dialyzer) by tubes attached to your blood vessels. Your blood is slowly pumped from the body into the dialyzer, this is where the extra fluids and waste products are removed. The filtered blood is then sent from the dialyz

Epinephrine, the miracle hormone.

For this week’s blog I would like to talk about the role of epinephrine during cardiopulmonary resuscitation in the process of reversing cardiac arrest. I’ll start of by giving you some background information on Epinephrine. I’m sure you’ve heard of bizarre cases where an average man was able to do some miraculous task like lift a car off of someone else or something in that nature. What allowed them to perform such an unthinkable act? Epinephrine. Their body produced enough Epinephrine which allowed him to do it in the heat of the moment. Epinephrine is a hormone that is produced by the brain in the medulla. During periods of intense fear/stress the medulla induces the secretion of epinephrine, giving us the ability to react appropriately in the situation at hand. You may have heard of the flight or fight response. When the fight or flight response is induced, epinephrine is secreted, giving the body a surge of energy it needs. Cardiopulmonary resuscitation is an emergency p

Cyanide, second post

Cyanide Toxicity or Cyanide poisoning has been seen throughout history. It was first used in WWI as a chemical weapon in the form of gaseous HCN. The French military was known to use HCN but experienced no success due to the high volatility of cyanide. The French then started using cyanogen chloride which was successful due to the fact that it was much more toxic and less volatile. During WWII the British and American secret services developed cyanide pills that could be easily swallowed in order to commit suicide to prevent torture and extraction of important information. These pills were well known to be used by Nazis throughout the war. Most important Nazi representatives such as Adolf Hitler, Erwin Rommel, Heinrich Himmler, and Hermann Goring used cyanide pills when they were on the verge of being captured. Cyanide exposure can also be unintentional. Cyanide is found throughout the environment. Therefore, an individual can be exposed to cyanide without being aware. One can be

Electrocardiogram

This week I’d like to take a break from my usual post on genetic diseases. I want to talk about a machine used in every Ambulance, medical provider’s office and hospital called an electrocardiogram or ECG/EKG for short. Electrocardiograms is a simple machine that detects and records the heart’s electrical activity. Basically, an ECG can show how fast the heart is beating, the regularity of the heart’s rhythm, the strength and timing of the impulses passing through one’s heart.   So how does an Electrocardiogram work? With each heartbeat, a signal is sent throughout the heart that correlates with the flow of blood. This signal helps gather the P wave, QRS waves, and the Q wave on an Electrocardiogram. Each electrical signal begins in a group of cells called the sinus node (SA) which is located in the right atrium. From the SA node, the signal travels through the right and left atria which causes the atria to contract thus helping get blood to the ventricles. The electrical signal