Chem 13H Elements of Life Posters 2005

Many links have been found between Parkinson’s disease and high levels of iron in the brain. The iron controlling protein, ferritin, can only monitor iron concentrations of a healthy human brain. Ferritin alters the iron, creating a non-toxic molecule that can be stored and is readily available if needed. Since a Parkinson’s diseased brain has an excess of iron, ferritin cannot control the surplus. As a result, the extra iron kills cells, creating toxins that poison and deteriorate the brain. Exploring the relationship between iron and Parkinson’s disease can guide research to help slow down or cure the disease.

Normally copper aids in the neuron functions in the brain and is an essential trace element that is active in the mitochondria of the liver. When the enzyme, cytochrome oxidase, of the mitochondrial cell is deactivated, the autosomal recessive disorder known as Wilson's Disease results. The resulting build-up of copper in the metabolic pathways of the nervous system causes muscular rigidity, spastic muscle contractions, and eventually mental deterioration. The copper, because of its redox reactivity, accumulates in the cells causing damage through oxidative modifications of proteins, lipids, and nucleic acids. Neuronally active substances that control basic human function, are affected by the inhibition of the enzymes dependent on copper. Wilson's Disease, because of the severity of the cause, is being experimentally treated with gene therapy, which injects the healthy gene controlling the enzyme expression into the organism's genome.

Because of its excellent biocompatibility, as well as ideal strength-to-weight ratio, titanium is the material of choice for bone-contacting implants in restorative medical procedures and dentistry. Titanium oxidizes spontaneously and forms a protective TiO₂ layer on the surface of the implant. This allows for interfacial interactions with the bone and promotes cell adhesion and bone regrowth. Currently, studies are being done to develop ways to make this interaction even more favorable. A number of groups have completed experiments using different surface grades of titanium and after analysis with SEM, it was determined that a grooved titanium surface produces the best bone-implant interaction, allowing for the most cell adhesion and spreading.

Strontium can replace Calcium in the transmission of neurotransmitters in the brain. Peak efficiency of neurotransmitter transport is lower for strontium than for calcium, but last much longer. When strontium controls neurotransmitter release, the release is more asynchronous than it is when regulated by calcium as a result of the cell membrane's affinity for calcium. Strontium also acts as an effective antagonist of Calcium's neurotransmitter release by binding to the external cell membranre where divalent cation entry is regulated.

Get the Lead Out!

Mac Pedlow
Lead

Throughout human history, lead has been used for all sorts of products due to its malleability, weight, and abundance. From pipes in the Roman Empire to more recent uses in forms of gasoline (tetraethyl lead) and some paint (lead carbonate), it has been part of many people’s lives. In the 1970s, it was found that high amounts of lead in the bloodstream can cause neurological damage, anemia, and even cataracts in the eye. Lead impedes the formation of blood cells and interferes with nerve cell signaling, and therefore affects the way the brain thinks. High enough levels can cause mental retardation, comas, and death. However small the individual doses, quantities can build up over time and become dangerous, which makes lead poisoning a common occupational disease. Today, lead has been phased out of gasoline, paint, and piping at great expense. I plan on discussing the effects of lead poisoning on the human body, though little is known about the chemistry behind how lead causes the damage. Instead, I will discuss the chemistry behind lead products, particularly the tetraethyl lead used in gasoline and the lead carbonate in paint.

Synapses are the spaces between neurons. At chemical synapses, chemical messengers (neurotransmitters) leave the terminal button of the sending cell and are taken into the receiving cell through special channels. Calcium plays a vital role in this process. When the sending neuron is stimulated (as by another neuron), there is an action potential, which is a change in the electrical charge within the neuron relative to the outside of the neuron. This causes voltage-gated channels to open, allowing calcium ions to flood into the terminal button. The Ca2+ ions, in turn, cause vesicles (“neurotransmitter waterballoons”) to fuse with the presynaptic membrane and empty their neurotransmitters into the synapse. High frequencies of action ponentials result in great amounts of calcium flooding the terminal button, and the concentration of calcium in the extracellular fluid is also important. The main delay in such transmission is caused by the time needed for calcium to enter the cell.

Influence of Zinc on Cell Suicide

Ryan Modrak
Zinc

Apoptosis, or cell suicide, is a carefully regulated physiological process important in the development of the immune system and in immune cell production. Though the control of apoptosis is extremely complex, zinc is known to play a key regulatory role. Zinc-dependent enzymes directly inhibit the activity of apoptotic enzymes and prevent the accumulation of toxic nucleotides which can trigger apoptosis. Zinc also functions as an antioxidant, helping prevent apoptosis by reducing damage to immune cells from oxygen radicals. From a nutritional perspective, zinc deficiency due to insufficient intake has been linked with increased incidence of apoptosis and decreased immune responsiveness.

When the study of the passage of ions into and out of cells first began, it seemed logical to deduce that all ion exchange occurring over a cell membrane happened spontaneously, due to diffusion. However, it is now known that the concentrations of sodium and potassium ions found within cells differ greatly from the concentrations found in extracellular fluid. The consistent ion gradient is maintained by Na/K ATPase pumps, which uses anywhere from twenty to even seventy percent of a cell’s metabolic energy to move sodium ions out of the cell and to bring potassium ions in. This constant flow of ions helps to maintain the cell’s membrane potential as well as aiding in the transport of various other ions, such as calcium and hyrdrogen ions, into and out of the cell. Other uses of the Na/K ATPase pump as well as its mechanics will be discussed in the presentation.

Ions and Dehydration

Beth Tirio
Potassium

The Na+/K+ pump, as described by Rocco Panella, is important in regulating the intra- and extra-cellular concentrations of sodium and potassium ions. When the concentrations are altered, a number of serious medical conditions can appear, most notably cardiac arrhythmias. When a small concentration change arises, the pump is normally able to adapt and thus prevent such serious medical conditions from occurring. When one becomes dehydrated, the total volume of water decreases, both inside and outside the cell, thereby creating a much higher concentration of ions on either side of the cell membrane. The Na+/K+ pump is unable to achieve the proper concentration of ions in this reduced volume state, and medical complications are of concern. The increased concentration induces drastic physiological responses and is the reason dehydration is such a threat to serious athletes.

Going Looney for Lithium

Going Looney for Lithium: Lithium’s Role in Bipolar Disorder

Lauren Aldinger
Lithium

Lithium was first discovered to have therapeutic effects in treating bipolar disorder beginning in 1949. Since that time, extensive research has been done to understand the mechanism by which lithium has its effects on manic patients. The leading theory is that lithium works by inhibiting inositol monophosphate (IMPase), which modulates the phosphoinositide signaling pathway (PI). By inhibiting IMPase most severely in the hypothalamus, lithium prophylactically stabilizes the disorder by reducing the frequency and severity of mood cycles. The specific mechanism of this inhibition will be discussed. .

The “Cobalt Bomb” Beats Cancer

Matt McCowan
Cobalt

In 1951, the first Cobalt-60 Beam Therapy Unit was developed in Canada. The pessimistically named “Cobalt Bomb” treated cancer patients by bombarding a malignant tumor with gamma rays caused by the decomposition of the ⁶⁰Co isotope. Because cancerous cells divide much faster than normal cells, they are much more susceptible to the effects of gamma radiation. The high energy photons are aimed at the cancerous site and allowed to enter the body, destroying the separating DNA molecules by forming inappropriate bonds. Although Cobalt-60 is being replaced by safer and more effective forms of teletherapy, it was an amazing discovery that saved many lives.

The Redox Behind Methanogenesis

Liz Francis
Nickel

Methanogenesis, or the production of methane gas, is a biological process performed in anerobic conditions by methaogenic archea bacteria; a phenomenon directly related to the greenhouse effect. Methyl coenzyme M reductase, a nickel containing enzyme, catalyses the final redox process of methanogenesis; an exergonic process involving the reduction of substrate methyl-coenzyme M (CH3-S-CoM) with substrate coenzyme B (HS-CoB) to produce methane and CoM-S-S-CoB.1 Cofactor F430, a highly reduced tetrapyrrole prosthetic group, is attached at the enzymes active site. Because this cofactor contains the nickel center, it is a direct component involved in the reduction of Methyl-coenzyme M.2 X-ray absorption spectroscopy and resonance Raman studies are used to study the two F430 containing methyl coenzyme M reductase containing states; MCR red1 (active enzyme) and MCR ox1 (inactive enzyme).2 Thus, through an examination of the F430 structure and the redox reactions of methyl-coenzyme M reductase, a deeper understanding of methanogenesis is established.

Manganese: The Life Sustaining Catalyst

Laura Hoch
Manganese

One of the many important functions of manganese is the roll it plays as the major component in the catalytic reaction that makes the complex process of photosynthesis possible. Manganese has many interesting chemical properties such as its electron configuration which allows it to function as a good catalyst in many reactions due to its unusually high number of oxidation states. The portion of the photosynthetic process catalyzed by manganese is called photosystem II. This compound, Mn4O4n+ cubane, also called the Oxygen Evolving Complex (OEC), is the core-component of the reaction that involves the light-stimulated oxidation of water to dioxygen and the reduction of quinones to quinols (3). This process splits water molecules into protons and oxygen, freeing electrons and releasing energy, to be used in other processes (2). Although its exact molecular structure remains unknown, current research indicates that the most probable structure is a somewhat distorted cubane form (1), composed of four manganese ions, one calcium ion, and a number of oxygen atoms (2). Scientists are currently trying to synthesize inorganic models that resemble the manganese complex in an attempt to use it to harness the energy potential of photosynthesis. However, much of the inner workings of this process remain unknown and more research is needed to fully understand what actually occurs during the photosynthetic process.

Chromium, the Lifeblood of Insulin

Merika James
Chromium

The extremely low percentage of absorption of dietary chromium in humans makes it incredibly difficult to study its function in tissues and bodily fluids. Chromodulin, a unique chromium binding oligopeptide, has been shown to stimulate insulin activation without changing its concentration. Chromium, moreover, is part of the insulin signaling autoamplification system. After eating, glucose levels in the blood rise, in a healthy person; insulin is then released to help control these levels. Chromium has proved to be an integral part of insulin signaling and may have the ability to aid non-insulin dependent type II diabetes patients. People with type II diabetes have plenty of insulin and do not need insulin shots, however; they lacks the ability to use the insulin that is already present to the desired degree. Since there is no reliable means of measuring chromium levels, the only way to diagnose the deficiency is to observe its positive effects from supplementation.

Sulfur: Bacteria’s Worst Nightmare

Nicole Williams
Sulfur

Sulfur is one of the most important elements to human health. It has numerous biological and medicinal uses, and these have been recognized since Biblical times. In my discussion and poster, I will concentrate on the continuing effect sulfa drugs have on society and what characteristics of sulfur contribute to this. Additionally, I will discuss sulfa allergies, and the possible interactions between sulfa drugs and other medications, and how and why these happen.

Silica Nanoparticles as Biomolecular Transport

Eric Myers
Silicon

Biochemistry has found several uses for silica nanoparticles in molecular transport. Silica nanoparticles, hollow spheres usually consisting of SiO₂ polymers, have been synthesized through various means, including hydrolysis of tetraethyl orthosilicates. These spheres can be designed to contain or attach to luminescent substances, medicines, nucleic acids, proteins or other biomolecules. They can be guided using optical trapping, magnetic fields, or proteins on their surfaces. Such a method for guiding biomolecules has many diverse applications in nanomedicine.

Pandora's Poison: Organochlorines and Health

Sucharita Mukherjee
Chlorine

Organochlorines are organic compounds of chlorine that have undergone the chemical effect of chlorination. The chemical process of adding the element chlorine affects the stability of the organic compound and has also been known to create environmental and health problems. Through molecular biology studies, it has been revealed that organochlorines disrupt biological processes at the most fundamental levels. In particular, recent research has focused on understanding the correlation between organochlorines and cancer. Studies have shown that over 100 organochlorines cause cancer through a variety of mechanisms, including: genetic mutations, hormonal changes, immune suppression and induction of enzymes that make other compounds more carcinogenic. Overall data suggest that industrial pollutants, such as polychlorinated biphenyl (PCB) congeners and dioxins, are involved in the increasing cancer rates. However, further study must still be completed in order to report data conclusively.

Barium and X-ray Imaging of Soft Tissues

Jennifer Clark
Barium

X-rays, a high energy (200-200000eV) form of electromagnetic radiation, are often used in medical imaging. However, soft tissues such as those found in the rectum and colon, have small x-ray cross sections and thus x-rays easily pass through them. The x-ray cross section measures the probability of an x-ray interacting with the nucleus, and increases as atomic number increases. To image soft tissues, radiologists inject liquid barium sulfate to coat the rectum and colon. As a heavy alkaline earth metal, the barium has a higher x-ray cross section and blocks the x-rays, allowing images to be taken.

Tc-99m: The Backbone of Nuclear Medical Imaging

James Monaco
Technetium

Since its discovery as a decay product of neutron-doped Molybdenum-99, the Tc-99m isotope has become the backbone of modern nuclear medical imaging. Tc-99m is a chemically reactive, radioactive metal that releases a singe photon of 141 keV radiation upon decay. Its advantages as a nuclear imaging agent are numerous. Its production is relatively simple and inexpensive. The radiation it produces is in small enough quantities and at such an energy level as to pose minimal risk to the human body while still being easily detected by gamma radiation sensors. The isotope’s half-life is only 6 hours, which allows the time patients spend exposed to radioactivity to be minimized. Finally, technetium can occur in oxidation states from +1 to +7 and is quick to bind with a wide variety of biologically-active ligands, allowing for the creation of technetium-infused molecules that mark very specific organs or tissue types. The properties of this element have allowed Tc-99m Single Photon Emission Computed Tomography (SPECT) to become one of the most effective and widely used imaging techniques in the field of nuclear medicine. In this procedure, Technetium markers are injected intravenously, and allowed to be absorbed by the target organ or tissue. Gamma ray sensors then measure the radiation output from the patient’s body. By using a computer to interpret the data, a detailed series of cross-sectional images of the target organ can be produced. Modern systems can even reconstruct these cross sections into a three-dimensional virtual model of the organ, allowing doctors to quickly and easily see where any abnormalities lie.

Mild Hypothyroidism in Fetal Brain Development

John McManigle
Iodine

Follicles in the thyroid gland absorb trace amounts of the iodide ion from the blood and produce the hormones thyroxine (T4, 3,5,3',5' tetra-iodothyronine) and triiodothyronine (T3). Iodine-deficient patients often exhibit goitre, enlargement of the thyroid. In iodine-deficient but affluent areas, goitre has been eliminated by the use of iodized salt. However, the thyroid hormones, particularly thyroxine, are important in neonatal brain development. Pregnant women who are marginally iodine-deficient are much more likely to give birth to children with ADHD.

An Answer for Cancer

Matt Wendahl
Platinum

Cisplatin (cis-diamminedichloroplatinum(II), Cl₂ H₆ N₂ Pt) came out of nowhere in the early 1970’s completely accidentally, and has evolved into a cornerstone in the foundation of cancer fighting agents. When you hear the world “chemotherapy,” cisplatin or second-generation platinum drugs derived from cisplatin are likely a primary ingredient, especially if the cancer in question is testicular, ovarian, bladder, or head and neck. Cisplatin is by far the most effective against testicular cancer, with a 95% cure rate when combined with other drugs. The root of cisplatin’s effectiveness comes from how it hinders what cancer cells do best: replicate. The only problem exists in the fact that cisplatin has incredibly toxic effects on the kidneys and hearing, limiting its dosage, which is something scientists are still trying to solve 27 years after its entrance into the battle against cancer.

Not for Morons: Boron Neutron Capture Therapy

Jocelyn Fitzgerald
Boron

Boron neutron capture therapy is an up and coming therapy targeting brain tumors. BNCT is considered to be a “binary therapy” because it requires two non-toxic agents, boron and a stream of neutrons, to work together to make the procedure successful. A Boron compound is administered, because they work best on the brain, but it is the isotope B-10 that picks up lots of neutrons and is most effective in cancerous cells (and not normal brain tissue). It is administered as a drug while the malignant site is irradiated with a neutron beam. When neutrons are captured by B-10, the high energy particles that result from their union deposit their energy locally, within a diameter that is about equal to one human cell, approximately 3-10 microns. Cancer cells are capable of receiving much higher doses of radiation even if the normal ones are close by. It is thought that because of this characteristic, BNCT will be able to control cancers that disperse themselves amongst normal cells and tissues and will be able to go where other radiation therapies have not before.

Peripheral Polyneuropathy Caused by Ointments and Skin Care Products Containing Ammoniated Mercury

Phil Cerami
Mercury

Peripheral polyneuropathy is a disease of the peripheral nervous system (nerves of the arms and legs.) The myelin sheaths that surround the nerves of the arms and legs are gradually worn away, causing weakness and paralysis of the arm and leg muscles due to reduced conductivity in the nerves. Using a NCS (nerve conduction study) and an EKG (microphone-assisted muscular signal frequency study), this disease is diagnosed. Many case studies show that individuals who have used skin care products (for the treatment of psoriasis and other rashes, etc.) containing ammoniated mercury compounds have developed cases of peripheral demyelinating polyneuropathy. Increased mercury levels in urine tests of patients confirm the mercury use. After not using the mercury-containing products, the mercury levels in the urine went down and new conduction studies showed that the myelin sheaths were healing themselves. The conclusions made by these case studies showed that while mercury vapors generally are the main cause of mercury poisoning, the use of inorganic mercury compounds in skin-care products, or to a larger extent, the use of inorganic mercury for the use by the general public should and needs to be strictly restricted.