Tuesday, May 2, 2017

Nuclear- Positron Emission Tomography (PET)

Positron Emission Tomography (PET) scan allow doctors to scan the internal structure of a human body to see how the tissues and organs function so they can identify if an individual carrier any of the following conditions, which include cancers, heart disease and brain disorder. Beside detecting if an individual have any of the problem above, it can also assess the effectiveness of treatment plan, determine specific problem within the main problem above and determine the spread of cancer inside the body. As a result, Positron Emission Tomography is commonly used by oncologist, neurologists, neurosurgeons and cardiologists.
The way that the Positron Emission Tomography machine work is by detecting the gamma rays and send it to the computer. The computer will analyze the gamma rays into information that will be use to create the image. In order for the gamma rays to be emitted from the patient body the patient will need to consume tracer, which can either be injected, swallow or inhale into the body. Tracer is a chemical compound that have a radioactive atom attach to the chemical substance that is used by the particular organ or tissues during it metabolic process, which is a process where the cells produce energy and other substance to sustain its life. Due to this reason, there are many type of tracers because different organ or tissue require different tracer. For example: The tracer that is use for PET brain scan is fluorodeoxyglucose, which is made out of a flouride-18 and glucose because the brain use glucose during it metabolism process. The structure of this tracer is shown above. When the tracer enter the body and reach the target organ or tissue it will gather in the area with the highest levels of chemical activity because this is where the disease will take place. When this occur the radionuclide in the tracer will undergo radioactive decay process where it will break down the atomic nucleus and emit positron. Positron is a particle that has a positive charge and has the same mass as an electron. The positron will collide with an electron in the tissue to release energy in the form of gamma ray, which is an electromagnetic waves that is emitted when the nucleus change from an excited state to a ground energy state. Afterward the scanner will detect the Gamma ray and use the computer to process it into an image. The affect tissues will appear to be very bright because this is where most of the radionuclide gather up and emit the most gamma ray.
In conclusion, it show that Positron Emission Tomography scan is very important in the medical field because it is use to detect some of the most serious diseases that is hard for doctor to cure, which are cancer, heart disease and brain disorder.

Work Cited
Modern Chemistry by Holt McDougal


Posted by at 6 comments:
Labels:

Nuclear Chemistry- Chernobyl - Harrison

       The Chernobyl Incident was a graphically tragic period of time, resulting in a massive fallout and radioactive decay zone. This zone is still radioactive to this day, and as time is passing, only grows worse. However, a new way to contain this leakage of radiation has taken a turn for the better. To understand how it works, however, one must understand how a Nuclear Reactor works. Reactors, in essence, use fission to release energy and split neutrons. The Chernobyl reactor's system failed, as well as the safety protocols, and began to overheat, melting down and releasing those split neutrons and radiation resulting from the fission. Currently, the reactor is shielded with a thick layer of concrete, acting similar to a sarcophagus.
However, this shield is failing, and the radiation is breaking the concrete apart, as the structure wasn't strong or durable to begin with. The radiation levels have expanded, and are listed on the image, along with the effects. It is necessary to know that 50mSv per year is equal to 3-25 uSv/hr. Another common measurement is roentgens, to which 0.00877 Sieverts (Sv) is equal to 1 roentgen. Various conversions are also important:
1,000,000uSv = 1Sv
1000mSv = 1Sv




As these effects are such, the necessary work on the project known as "NSC" or "New Safe Confinement" was begun, and the project will be completed sometime within 2017. NSC is a large steel arch designed in a manner to keep Chernobyl contained for the next 100 years. By hermetically sealing the building, the nuclear materials will remain contained within it, unable to escape. It will act as shielding, preventing the rays of radiation from escaping and effectively containing the radiation. As well as this, since it is made from steel, it is less susceptible to the effects of radiation than the previous coffin.
This new coffin will allow the workers to attempt to remove the nuclear waste from within Chernobyl and prevent radiation from spreading, as well as nullifying the reactor. The reason that they must remove these materials is due to the half-lives of the Cesium within Chernobyl. Some interaction, currently unknown, within the soil of Chernobyl, has expanded the half-lives of the Cesium from the normal 30ish years, to between 180 and 320 years. Cesium may not seem as dangerous as plutonium however, as plutonium can cause much much longer damage. However, the Soviets put a much larger amount of cesium in their reactors compared to the normal amounts of plutonium. If the radiation pertains for its true lifespan, Chernobyl may have a hard time ever becoming habitable again, as the effects from the radiation are already evident in several zones, such as the "Red Forest", which was one of the five most contaminated areas within Chernobyl. In the "Red Forest", deformities are everywhere. The trees, although dead, have barely decomposed and remain black trunks in the midst of the chaos. The radiation had caused the environment to show 40% less decomposition. If these leaves and trees were to burn however, in the case of an event similar to a forest fire, radiation would be spread throughout the zone via the smoke.


- Harrison
Posted by at 5 comments:

Clinical Biochemistry

   Clinical Biochemistry

               Clinical Biochemistry combines pathology and biochemistry, which are closely intertwined. Clinical Biochemistry combines qualitative and quantitative analysis of biological fluids such as blood, serum,  urine, or tissue to screen for disease. Biochemistry is the study of the chemicals and reactions that occur in living organisms. Pathology is studied through biochemical changes. Clinical Biochemists are actively involved in applied research in order to create new diagnostic lab tests to identify and monitor disease.

             A common test is a Lipid Profile. A lipid is a type of biochemical that does not dissolve in water and is soluble in a non-polar substance. In the body, lipids make up the ouster layer of all of a person's cells and insulate nerve fibers. This test measures the amount of cholesterol and fats, also known as triglycerides, present in the blood. The test helps to predict a person's risk of heart disease which is caused by too much cholesterol in a person's blood, which begins to build up on the heart's arteries, causing atherosclerosis, a type of heart disease. With so much build up on the arteries, blood flow is constricted. Some other common tests preformed are, kidney functions, blood tests, liver functions, cholesterol tests, and Troponin and Cardiac Enzyme tests.

            Kidney function tests use urine, the color and pH of the urine are used to tell how the kidneys are functioning. A pH change is a chemical change and serves as an overall health predictor. Urine changing color is a physical change and is caused by the pigment urochrome, this does not signify any sort of health issue, it can simply be caused by a person's diet. The Troponin and Cardiac Enzyme levels test informs doctors if a cardiac injury such as a heart attack has occurred. An enzyme is a protein that catalyzes a biochemical reaction. Enzymes such as creatine phosphokinase, lactate dehydrogenase, and glutamic oxaloacetic transaminase, and proteins such as Troponin are found in the cardiac muscles. Very low levels of these things are naturally found in the blood, and when there is a cardiac injury, there is a release of these enzymes into the blood. Troponin is a complex of three regulatory proteins that is needed for non-smooth muscle contraction. It is attached to the tropomyosin which is located in the grooves between actin filaments in muscle tissue. See the lock and enzyme model below- it is very similar to this process.

                 High levels of NSE or neuron specific enolase in a person's cerebrospinal fluid can hint that the person has a form of a neurodegenerative disease or a form of small cell cancer such as small cell lung carcinoma. Enolase is a glycolytic enzyme that catalyzes the conversion of 2-phosophoglycerate to phosphoenol pyruvate. Enolase is a tissue-specific isoenzyme, an enzyme that catalyzes the same reaction but at a different rate, that is consisted of heterodimers, a protein composed of two polypeptide chains that differ in composition, order, or number, heterodimers can be expressed as alpha, beta, or gamma. The biological half life of NSE is twenty-four hours. Measurements of NSE levels in patients with neuroblastoma or small cell lung cancer can provide information on the extent of the disease, the prognosis(the patient's out-look), and the patients's reaction to the treatment. The picture on the left is a a label of were in the body a neuroblastoma can occur. The photo on the right is a close-up of the lungs, where small cell carcinomas form, and a close up of a small cell carcinoma. 




Resources:
http://www.questdiagnostics.com/testcenter/testguide.action?dc=TH_NSE







Posted by at 2 comments:

Biochemistry of DNA Fingerprinting

Biochemistry of DNA Fingerprinting
Since the 1980’s, DNA fingerprinting, also called DNA typing or DNA profiling, has been used to convict or release potential suspects in criminal investigations. DNA fingerprinting is also used in genetic counseling, childbirth decisions, and genealogy/ancestry. However, the use of these fingerprints is possibly the greatest tool used by criminal investigators.
DNA, deoxyribonucleic acid, is the blueprint the genetic makeup of a human being and exists in virtually every cell of the human body. DNA differs in the sequence of nucleotides (adenine, thymine, guanine, and cytosine), or variable number tandem repeats (VNTRs) in particular short tandem repeats (STRs). VNTRs can be inherited which can help trade the pattern or probability of a disease in a family. Individuals are extremely unlikely to have the same VNTRs; in fact, there is only a 1 in 64 billion chance that any 2 people would have comparable DNA. Comparable DNA does not even mean that the DNA is identical, it just means that the DNA is similar.



Fragments produced by various restriction enzymes can be used to identify individuals with the accuracy of a fingerprint. The commonly used methods for isolating and comparing genetic sequences include polymerase chain reactions (PCR) and restriction fragment length polymorphisms (RFLP). PCR is ideal for analyzing small amounts of DNA and the process involves a system of denaturing, annealing, and extending DNA. An increase of temperature triggers denaturing. The hydrogen bonds break between the double helix and they separate. In the process of annealing, the temperature is lowered, which enables primers to attach. Primers are segments of DNA that have a free OH group on the 3’ carbon of a nucleotide. These primers line up with specific sequences of amino acids. After the temperature is slightly increased, a DNA polymerase is able to attach nucleotides to the 3’ carbon of the primer and extend the complementary strand. Each temperature-regulated cycle greatly increases the amount of DNA present, which makes more available for amplification in the next cycle. After a lengthy process PCR strips can be viewed for analysis
RFLP comparisons are much more specific tests, but require DNA samples of very high quality to work effectively. The procedures are also more labor-intensive than PCR and involve the addition of NaOH in gel to alter the pH and break the DNA molecules into single strands. The variability in the types and sizes of probes allow RFLP to reveal a large amount of very specific information. The membrane can be cleaned of any probe and retested with another providing an even larger amount of data.

Works Cited:
http://www.wiley.com/legacy/college/boyer/0470003790/cutting_edge/dna_fingerprinting/DNAFingr.htm
http://edusanjalbiochemist.blogspot.com/2013/06/dna-fingerprinting.html
https://www.youtube.com/watch?v=ZxWXCT9wVoI


Posted by at 3 comments:

Immunology (Biochemistry)

The study of immunology is the study of the development, anatomy functions and biochemistry malfunctions of the immune system, fundamental aspects to understanding human disease.  Biochemistry is the study of how cells work at molecular level. Biochemistry (and the related field of molecular biology) are both important in the understanding the molecular basis of life, along with its role in the disease process (relating to immunology- studying the immune system).  The immune system is made up of many types of molecules and cells that are in every tissue of the body, including specialized lymphoid organs, (which act in a together to prevent or stop microbial infections), to suppress or stop the growth of tumors, and to repair damaged tissue.  Studying immunology and receiving a degree will allow you to succeed in many fields of biomedicine such as neuroscience, cardiovascular research, immunopharmacology, industrial immunology, drug research, biochemistry, microbiology and bacteriology.  When studying clinical biochemistry and immunology, students use many different types of basic qualitative and quantitative methods of research and analysis in studying liquids such as blood, plasma, urine, etc to search for specific chemical patterns or processes. Biochemist immunologists also used methods of applied research to create new diagnostic clinical laboratory tests to identify or monitor disease, disease processes, or treatment of disease. Testing that uses applied research in immunology include evaluation of immune factors causing disease, monitoring chemical response to cancer treatment, evaluation chemical’s reaction to toxic drugs and metals, and many more. A recent current event in the field of biochemistry and immunology is that researchers at Harvard Medical School have been studying the field of biochem-Immunology for basic research, and they have made some recent discoveries using new technology and methods of studying that could change the medical field forever. They have been working on research developing many new therapies (which include Transcriptional profiling and proteomics of the many different subsets and functional states of the cells of the immune system, in vivo confocal and multiphoton imaging of pathogen-host cell interactions, and studies of the manipulations of the intestinal microbiome on immune responses and autoimmune disease), but one of the most intriguing ones and one where they have made a fairly large discovery in by basic research is their findings in evaluating blockades of T cell inhibitory molecules, which they found could possibly work as a cure to cancer.  Inhibitory receptors (iRs) are frequently associated with “T cell exhaustion”. However, the expression of iRs is also dependent on T cell differentiation and activation. Therapeutic blockade of various iRs, also referred to as “checkpoint blockade”, is showing ­unprecedented results in the treatment of cancer patients.  The phenomenal clinical impact of the therapeutic blockade of iRs to restore T cell function in cancer (as outlined in the last parts of our review) has greatly contributed to the widespread acknowledgment of the functional importance of iRs.
immunology.jpg
Chart relating immunology, biology, and chemistry.




Video thoroughly explaining immunology and its relation with cancer (Harvard’s research)
immune sustem.png
Chart explaining the basis of the immune system- essential to understanding immunology.

 Works Cited:
http://www.nature.com/nrc/journal/v12/n4/full/nrc3239.html
Posted by at 2 comments:

[Biochemistry] Metabolic Processes of Organisms


              Humans and animals create energy by consuming food and then breaking it down in the stomach through metabolic processes. Metabolism is the sum of all the chemical reactions that take place in each cell of a living organism to maintain life. All organisms that have cells go through the metabolic processes of breaking down something that is consumed, and turning it into energy. Plants do this by a process called photosynthesis, in which plants take in sunlight and then convert it into energy for the plant to use. The process is very important because this is the way that organisms make energy so that they may stay alive. 

Image result for photosynthesis           Currently, scientists are working on determining whether characteristics in human metabolic processes could lead to certain diseases. The chemists have done this through fitness testing with oxygen consumption. The way they are doing this is by testing a patient's oxygen consumption and their heart rate during intense workouts. This is the way that chemist can measure a patient's normal metabolic rate. Scientist are also studying patient's BMR of Basal Metabolic Rate. BMR is minimum amount of energy required to keep your body functioning. Scientist have linked their research to weightless while resting and to diabetic studies.
Related image            The rate of human's metabolism can be linked to his or her diet. The Metabolic Clinical Research Unit (MCRU) has created the Metabolic Research Kitchen to prepare controlled meals for their study subjects. This is how scientist can track what their patients eat and drink so that their data is more concrete. The scientist also created an experiment where the test subject may pick what food they want to eat. Scientist are hoping to discover how they made these choices, and what influences their decision. This research will show eating habits that could be a vital source of information in the scientist's studies.




Works Cited:
https://www.unm.edu/~lkravitz/Article%20folder/metabolismcontroversy.html
https://www.niddk.nih.gov/health-information/clinical-trials/metabolic-clinical-research-unit-volunteers/research-areas

Photos:
http://thelancet.com/journals/laneur/article/PIIS1474-4422(10)70224-6/fulltext

Videos:
https://youtu.be/fR3NxCR9z2U
https://youtu.be/kb146Y1igTQ

Posted by at 1 comment:

Biochemistry - Neurochemistry

Neurochemistry and its Role in Explaining Parkinson's


The scientific world has experienced leaps in research and establishing developments in understanding clinical neurochemistry, but there is always more to be discovered and innovated. For diseases such as Parkinson’s or Alzheimer’s and discovering their subsequent paths to recovery, a basic understanding of the neurons and neurotransmitters of the brain must be acquired.

Chemicals in the brain are called neurons. These neurons act as communicators for the brain, whether it be for emotional responses or action stimulators. They communicate with areas called neurotransmitters, which will send messages through small spaces called synapses. However, these messages will only be accepted by those who accept them, like a key. Once attached, they will use a “stop” or “go” signal to indicate whether that neuron should continue firing the signal to the others. All these processes occur in an instant. Then, after the action, all the neurotransmitters must then be gotten rid of, which can be done in one of three ways. Either the released chemical could be pumped back into the nerve ending, called “reuptake”, the neurotransmitter can be destroyed by nearby enzymes, or they may be spread to other areas of the brain and destroy them there. There are three types of neurotransmitters in the brain. These are dopamine, serotonin, and gamma-aminobutyric acids (GABA). Serotonin produces chemicals which cause the feeling that people associate with happiness. These chemicals can be used to treat conditions such as depression, social anxiety, or or excessive shyness. Dopamine is the neurotransmitter concerned processes of movement, emotional response, pain, and happiness. Imbalances in these neurotransmitters cause conditions such as Parkinson’s and schizophrenia. Finally, there is Gamma-aminobutyric acid (GABA). This is the main neurotransmitter which prevents a brain’s neurons from firing, acting as almost a stop light. Certain types of epilepsy are caused by a shortage of these chemicals.

Certain imbalances in these neurotransmitters and their production of chemicals cause diseases such as Parkinson's, Alzheimer’s, schizophrenia, and many others. Parkinson’s disease is a long-term disease that affects the movement of the affected person. Parkinson’s disease can be caused by a shortage of dopamine in the brain, or the neurotransmitters that control movement (See Figure 1). In order to advance their research in the area, a basic awareness of the causes of the disease must have been known. Research for potential cures or treatments for the disease are still ongoing, questioning past methods and continuing to build on past information of   the brain and the human body. In the past, deep brain stimulation has been used as a treatment for Parkinson’s. The procedure involves planting electrodes in a certain part of a brain to stimulate that area. There is no actual interference with the chemical production of dopamine involved. To this day, scientists are still unsure of exactly how these procedures work, but the best comparison given is to a pacemaker for the brain. Dr. Jill Ostrem, a doctor working on potential cures for Parkinson’s, explained, “We knew that if you created a lesion on the brain in part of the basal ganglia called the globus pallidus interna, which is also within the circuit of these deep nuclei within the brain that control movement, that if you lesion this part of the brain, the symptoms of Parkinson's disease would become better treated. So this led the possibility of implanting a stimulator there and delivering an electrical current, with certain parameters”. However, new techniques are currently coming to the surface as to best treat the course of Parkinson’s. Since activists have been raising awareness for Parkinson’s disease, much more companies have invested in their research of the Medtronic devices for deep brain stimulation. They’ve been researching new and faster ways to approach DBS electrodes. Before, the common procedure was to use an MRI to scan the brain in order to find the spots and map them. Then, during surgery, they would use microelectrode recording, or listening to the sound of the cells as they are moving through the brain. Through this, they could find the desired location for the electrodes. Now, they’re working on a way using a real-time MRI. The patient would be asleep for the entire procedure. The MRI would take the picture of the brain while the electrodes are being placed on. There would be no need for microelectrode recording, significantly decreasing the time required.

References:
Pictures:



Figure 1

Posted by at 4 comments:
Subscribe to: Posts (Atom)