Todd Alderman
Imagine a tree bearing elephant-ear sized leaves, spires of white and violet blooms exploding from each branch, and a growth rate to rival Jack’s beanstalk. All of
these qualities become a reality when looking at the family Paulowniaceae. This remarkable plant has evolved into what some would call a superior tree. An
impressive history follows these ancient angiosperms. Some scientists argue as to where, exactly, the Paulowniaceae belongs in the phylogenic tree. However while
botanists decide where to put it, the economists are putting it everywhere. With uses in timber markets, environmentalism, medicine, and even as ornamentals, they
are studying and analyzing to maximize this tree’s potential…and, of course, make a profit. In discussing the Paulowniaceae, I intend to describe all these aspects in
the hopes of increasing my knowledge and yours toward this family of angiosperms.
The Paulownia Tree originated in China. This has caused some confusion because in the process of traveling throughout the world, it has acquired many new names. Some examples of these are the Empress Tree, Lilac Tree, Bluebell Tree, Bone Tree, Elephant Ear, and Flowering Basswood. The Japanese call it the “Kiri”. On December 10, 1949, the Japanese botanist, Nakai, was credited with the naming of the family Paulowniaceae. He displayed enough distinction from the other families to create an entirely new one. The taxonomy of the Paulowniaceae begins in the order of Lamiales which belongs to the class Asteridae. Unmistakably, the Asterids belong to the phylum Angiosperm which is in the Kingdom Plantae. Finally, all classifications of Plantae are placed in the domain Eukaryote. (Maddison)
Two other families in the order Lamiales possess a plethora of likenesses to the Paulowniaceae. Due to the synonymy, some botanists choose to leave them in the family that they originally were classified in.
Cronquist claims Paulownias belong to the family Bignoniaceae. This family houses genera with many similarities to the Paulowniaceae. The Northern Catalpa (Catalpa speciosa, W.), for example, is also a deciduous tree with oversized leaves and basically the same overall look of the Paulownia tree. In fact, it is difficult to separate these two in the field. The Trumpet Creeper (Campis radicans, L.) is a vine that bears little resemblance until one sees the flowers. Only then can the Trumpet Creeper prove itself worthy of comparison. Although not clustered in a spire, this vine displays deep, tubular blooms very similar to the Paulownia. Plants of the Bignoniaceae family, however, lack endosperm and differ in ovary and seed anatomy from the Paulowniaceae. (Reveal)
Takhtajan places Paulownias in line with the family Scrophulariaceae. Another member of this family is the Foxglove (Digitalis Purpurea, L.). The cascading blooms of this perennial, although reaching only five feet in height, gives such likeness to that of the tree, that Paulownia has been nicknamed the “Foxglove Tree” in some areas. The Snapdragon (Antirrhtinum majus, L.) also belongs to the Scrophulariaceae family. Again the flowers bear resemblance, but the lack of any secondary growth restricts this family from containing the Paulownia. (Reveal)
Nine species of in the genus Paulownia exist today. They are the P. albiphloea, P. australis, P. catalpifolia, P. elongata, P. fargesii, P.fortunei, P. kawakamii, P. taiwaniana, and the P. tomentosa. Of these there are many subspecies, but these are the original nine.
Probably the most attractive feature of any Paulownia is its leaf. These monstrous megaphylls of the temperate zone measure an average of three feet across. The largest of these simple leaves tend to reside on the juvenile limbs of the tree. These broadly ovate leaves display either a three-toothed or three-lobed shape and have pinnate venation. Oppositely arranged, each one is covered in uniseriate trichomes on the lower side (some species have them on both sides). This gives it an excellent shield from the evaporating effects of the sun. Since the family Paulowniaceae is a deciduous tree, it must display secondary growth with the presence of a cork cambium. The stems are a smooth brown with dots of white lenticels scattered over the entire tree. Every species also contains a hollow pith. (Conservative Extension Service)
“Paulownia flowers are showy, violet-blue, bell-shaped, and perfect. Flowers appear on terminal panicles in upright clusters six to twelve inches long--.” (Hopper) The buds begin to appear in the late summer and mature in October. These golden buds are round and hairy. The fragrant, five-lobed flowers will be on display in the early spring before the leaves emerge. The Paulownia fruit “—is an ovoid, woody, egg-shaped capsule about 1.2 – 1.8 inches long.” (Hopper) These will remain on the tree through winter. Paulowniaceae have been known to produce fruit as early as four years old and the seeds will come in the million
s. A mature tree will produce an average of twenty million seeds per season (1,500 per capsule). The large number is due the Paulownia’s use of wind dispersal thus each seed is winged for maximum distance. Although the flower is very fragrant, no wildlife have been observed to be attracted to it.
Very little is known about the cytology of the Paulowniaceae. It does have a diploid chromosome number of 40 but a study has yet to be published on the embryological development and anatomy thus giving more reason for the controversy of how it is to be classified. In 1858, M. Pepin of England made an interesting observation. He noticed that if leaves were cut off in December and left on the ground, they would flower “in Mid-May without any loss of color or fragrance.” (Hu) We do know that germination is epigeal and because the hypocotyl is extremely small, the young plant must land on bare soil for conditions to be favorable. Light is also a requirement for seed germination.
This tree has made itself popular with people by its ability to grow at an awesome rate. During the first couple of weeks the tree will look similar to the tomato plant, standing only a few inches high. During this time it is establishing a strong taproot for acquiring nutrients. During the first year, the tree’s larger than average stem is cut off at ground level. For the second year of the P. elongata, records have been set of 28-30 feet in one growing season. These trees grow to an average height of sixty to seventy feet. The largest in the United States is in Evansville, Indiana. This Royal Paulownia has lived here for 66 years and is 64 feet tall and 67 feet across. (Hayden) Normally the Paulowniaceae grow to be an average of seventy three years old and slow their growth rate after the first ten years.
As was said before, the Paulowniaceae originated in China. It has one of the oldest histories of any cultivated tree. “A Monograph of Paulownia,” was written by Chen Chu in 1049 B.C. describing its cultivation methods. In the book, “On Qin Dynasty” (221-227 B.C.) we have the first record of a Paulownia plantation. Even back to 475 B.C., in the book “Mencius”, there is a record of Paulownia cultivation in China. (Callaway) It is said that the legendary Phoenix only rests on the branches of the Paulownia. A tradition was begun long ago that when a little girl was born, the father would plant a Paulownia. When the girl became engaged, the tree was cut down and made into a dowry chest also known as a Tansu. The Empress Tree became so revered in Japan that in 1880 Emperor Meiji added the leaves and flowers to the Order of the Rising Sun. This is an honor “given to high-ranking diplomats and officers who have displayed outstanding civil or military duties.” (Morlan) It was given to General Douglas McArthur in 1960 as the highest honor Japan endows. A Dutch East India Co. naturalist by the name of Franz Von Siebold was the first European to discover the tree. He named it after the Anna Paulovna, daughter of Tsar Paul I of Russia. There are many rumors as to how it traveled the world. The most widely accepted is that a Chinese porcelain company used the seeds for packing material during shipping. When the recipient was finished with the box, the seeds were simply scattered across the property and the wind took care of the rest. (Larson)
The Paulowniaceae has traveled far and wide; however, it does have its growing preferences. It must have full sunlight and well drained soil to thrive. The P. tomentosa, also known as the Royal Paulownia Tree, is the fastest and most tolerant of the living species. It has been found throughout the United States, Brazil, Russia, Australia and England. The P. catalpifolia is naturally confined to China but has been cultivated in the U. S. and Australia. Trees can grow in light, sandy soils, to hard compact clays. The P. tomentosa and P. catalpifolia are able to withstand extremely cold temperatures down to -4o F. Most other species tend to favor the more moderate range of 23o- 74o F. This is made possible by the brown trichomes of the calyces which provide excellent insulation for the buds during the winter months. Once more, the large amounts of trichomes maximize heat retention on the leaves during an unpredictable spring. The P. albiphloea, on the other hand, is known to react quite indifferently to 104o F weather. Altitudes range from 2,000 feet, by the P. albiphloea, to 6,500 feet, by the P. fargesii. (C.I.D.R.C.) Because of these vast ranges and abilities, the Paulowniaceae has been accused of being invasive. Canada will not allow it to be shipped across its borders.
Since the late 3rd century B.C., commercial utilization of the Paulowniaceae has been recorded. China has long utilized the tree for timber in making the Tansu. Today many attributes of the wood make it a favorable choice in a variety of applications. An Auburn University test group found that while slightly heavier than Balsa, the wood of the Paulownia was twice as strong. (Bottomly) This makes it ideal for roof beams, doors, paneling, molding, plywood, and cabinets. Gary Pugh of Knoxville, TN, uses Paulownia wood for the hull of the #6 “Hooters” Powerboat. (Augustine) High quality musical instruments are also made from the sound absorbing wood. “The timber is the best in the world for printing on, and is used for business cards in Japan. (Lucas) In medicine, the Paulowniaceae is known to suppress dizziness and delirium related to typhoid fever and also in the treatment of bronchitis. (Tang)
Due to its diversity and exotic origin, the Paulowniaceae is not known for being inexpensive. If one were to shop for a new custom Tansu, he/she can be prepared to spend around 60,000 U.S. dollars…that’s not to mention shipping from Japan. Since Japan has exhausted its supply, we are now supplying them with $6 million worth of Paulownia timber every year. (Augustine) A high quality, close-grained trunk, measuring roughly twelve feet in length is valued at $10,000.
For the price of prestige also come risks. In February of 1992, King George County, Virginia experienced thefts of eight mature trees. It was around $50,000 in trees. These reports are scattered far and wide of people attempting to find a quick buck during tax season. Unfortunately, all they find is a case of grand larceny. (McKelway) Although it has been difficult to find a concrete niche in the United States, many investors have assisted in the new market. “Former President Jimmy Carter -- has 15 acres of Paulownia near his home in Plaines, GA, -- [which] are managed by Scot Corbett, president and CEO of Carolina Pacific.” (Associated Press)
Yet another quality the Paulowniaceae possesses is the ability to restore the environment. Due to the enormous leaves it bears the Paulownia “produces three to four times more oxygen than any other known tree.” (Morlan) According to Dr. Peter Beckjord, of the University of Maryland, “the heart-shaped leaves absorb sulfur dioxide, the gas that is the precursor to acid rain.” (Hager) Also, “in the city of Chendou in China, intensive planting of Paulownia decreased the air pollution by more than 80 percent.” (Lucas) By combining these attributes, the Paulowniaceae has become a genetically superior soldier in the fight for the environment.
On top of everything else, the beauty of the Paulowniaceae family can not be forgotten. It’s cascading blooms resembling orchids of violet and white make this tree a striking ornamental. Planted one year, it can be expected to provide cool shade by the following year. What other tree can compete with that? Even the leaves make a good fertilizer, in the fall, for the coming spring. As an ornamental this family is an ideal candidate.
In attempts to preserve these trees, associations have been formed to educate and disperse the Paulowia’s secrets and seeds worldwide. With genetic studies being done; many groups have improved growth rate and environmental tolerance throughout the family allowing for diversity even among the same species. One of the most prominent organizations is the American Paulownia Association. It was established in 1992 and holds annual meeting throughout the southeastern states. The APA has become world renowned for its botanical research and literature on the Paulowniaceae family.
Whether looking for tradition, quality timber, or simply a quick shade tree, this family can step up to the plate and make it possible. The Paulownia has etched its way
into landscapes across the globe. Its strategy for survival has proved successful throughout history making it a monument of strength in the Plant Kingdom. The beauty of the Paulowniaceae family will be enjoyed for generations to come.
Works Cited
Associated Press. “Industry slow to let fast-growing tree into wood market.” The Times Union 9 July 2001, Jacksonville, Florida ed.: B-3.
Augustine, Don. “Paulownia and Powerboat Racing.” American Paulownia Association 6.4 (1997): 1-4.
Augustine, Don. “Paulownia’s Lessons, Part II.” American Paulownia Association 5.3 (1996): 6.
Bottomley, William J. Paulownia Supply of America. Oct. 21, 2003 http://www.paulowniasupply.com/paulownia_vs._balsa.html.
Callaway, Ray. “Paulownia elongate very useful in U. S.” Carolina Pacific April 1994, 2.
Canada’s International Developing Research Centre. “Ecological Requirments of Paulownia.” American Paulownia Association 9.3 (2000): 1-7.
Cooperative Extention Service. How to Produce and Market Paulownia. Maryland. Bulletin 319, 1997.
Dong, Hanmin, ed. Paulownia Cultivation and Utilization in China. Proceedings of the First Annual Conference of the American Paulownia Association, Inc. Oct. 8 1992, Gainesville, Georgia, Agricultural Extension Service, 1993.
Hager, Mary. “Wonder Plants.” Newsweek 23 Nov. 1992: 3-4.
Hayden, Maureen. “Memorial Tree Sets A National Record.” American Paulownia Association 3.3 (1994): 1.
Hopper, George M., ed. Biology and Silvics of Royal Paulonia. Proceedings of the First Annual Conference of the American Paulownia Association, Inc. Oct. 8 1992, Gainesville, Georgia, Agricultural Extension Service, 1993.
Hu, Shiu-Ying. “Physical Properties and Anatomical Characters of Paulownia Wood, Part II.” American Paulownia Association 8.3 (1999): 1.
Larson, Robert. “Seventy-Seven Members From Sixteen States Pledge Support!” American Paulownia Association 1.2 (1992): 1-3.
Lucas, Chris. “Analysis of a New Industry.” American Paulownia Association 6.4 (1997): 1-4.
Maddison, David R. Tree of Life Web Project. Nov. 10, 2003 http://tolweb.org/tree?group=Lamiles&contgroup=Asterids.
McKelway, Bill. “Paulownia trees’s value at root of thefts.” Richmond Times-Dispatch 19 April 1992, B-2+.
Morlan, Johnny W. JWMorlan’s Unique Wood Gifts. Oct. 21, 2003 http://www.morlanwoodgifts.com/MMO11.ASP?pageno=86.
Reveal, James L. PBIO 450 Lecture Notes on Selected Families of Angiosperms: Asteridae. Oct. 21, 2003 http://www.inform.umd.edu/EdRes/Colleges/LFSC/life_sciences/plant_biology/p b450/c....
Tang, R.C., ed. Paulownia: Properties, Utilization and Research Needs. Proceedings of the 1996 Annual Meeting of the American Paulownia Association. Oct. 25-26, 1996, Montgomery, Alabama, Auburn University School of Forestry, 1997.
Тодд Aлдерман
“Иван Васильевич” is obviously a well renowned comedy from Russia. It had classic comedic lines that have been used in many countries. This film utilized many historic Russian events to heighten its comedic value making it one to remember. Since its original release, some of its humor has been reused even in American comedies. The acting in the film was similar in quality to the acting of Hollywood at that time. Many similarities can be seen in America and Russia simply by watching such a comedic favorite.
“Иван Васильевич” takes place in the city of Moscow, in what seems to be an apartment complex in the middle of the city. Shurik, a disorganized scientist, is experimenting with the prospect of time travel. He has built an experimental prototype but is finding difficulty in supplying enough voltage to power the machine. The apparent landlord, named Ivan Vasilevich keeps badgering Shurik to the point of threatening to report him to the government. Shurik’s wife is apparently having and affair with a producer that she works for and walks into the apartment to tell her husband that she is leaving him and is going to Gagry with her lover. Meanwhile in the suite next door, a common thief has broken in and is stealing common items from the film maker that lives there. Now once Zinochka (the wife) leaves, Ivan Vasilevich walks back in badgering Shurik and saying he must register his machine with the government or be arrested. He quickly explains that it is a time machine and that it works now and he can prove it. He swiftly cranks up the machine and after some gurgles and strange movie magic, the wall adjacent to the producer’s suite vanishes and the burglar is amazed to see the two gentlemen in the room next to him. He enters the room with the Shurik and insists on knowing what is going on, while Ivan Vasilevich demands to know what he was doing in the producer’s room. The thief blows him off and asks for another demonstration. Shurik then sets the machine back to the days of Ivan the Terrible. Chaos breaks out when Shurik opens the portal again and Ivan the Terrible sees the three men and calls them demons. The thief and the landlord run into the past through the time portal and Ivan the Terrible runs into the present time. Now a guard throws a spear into the machine and short-circuits it thus closing the portal and trapping everyone where they don’t belong. The two men are chased around the palace until they disguise themselves as the tsar and a prince. The real tsar is in Shurik’s suite waiting for repairs on the time machine and begins to learn about his host and what is going on in his life and how he has traveled through time. Now after much chaos in the present and the past, the machine is fixed and the characters are returned to there correct times. However, after the adventure is over Shurik awakes to find that the entire thing is just a dream. Even Zinochka’s affair was a dream and Yakin, the producer, doesn’t even exist. Shurik is just ecstatic that everything is back to normal and that he didn’t mess up history.
This tail uses many quick-witted jokes with ironic lessons and if it were a film in English of the same time period, I would probably not be able to distinguish it from any American film. The comedy used is common to all countries but is just applied based on the history of the particular culture. For example the joke about the man on the street selling capacitors has been used in many countries but has just been done with different products. Also the chase scenes in comedies are often done in high speed to increase the hilarity. Obviously this film is a classic because the same type films in America were becoming classics as well.
Russian culture in the film is displayed in the way of life for the actors. I can safely assume that most inner city life is lived in apartment complexes of roughly the same size as Shurik’s. And most of the clothing was common to the people of that day. All of the interior decorating was probably common to the people of Shurik’s status in the community. All of this was not very different from any other country. The landscape of the Russian monuments was the only thing that set it apart from any other county’s inner city life.
Overall “Иван Васильевич” is a popular comedy in Russia not because of the culture of the country but because of the people in the country. The humor used is common to all people no matter the country, and films from all over the world used this type comedy because all people are amused by the same type of jokes. Any film would have used the same comedic approach to entertain the audience of that time. This classic Russian comedy will be remembered, not because it was a Russian film or because it is about Ivan the Terrible but simply because it was funny.
Todd Alderman Lab C
A Case Study of the Central Nervous System
Here is a patient dealing with several different problems. With a very basic diagnostic, we can see that she is a 63 year-old African-American female which means that she is more prone to high blood pressure just based on studies done. Unaware of any medication she is taking, we see her blood pressure to be 139/105. This is above normal and if she is on any medication for this it would be even higher without that medication. After the patient describes her problems, we decide to test her cognitive, motor, and sensory skills to decide what exactly has happened. By this time we have already theorized that our patient is suffering from a stroke based on her complaints and condition of health. The purpose of the tests is to isolate the area of the brain that is affected and how extensive the damage is in order to treat the patient effectively.
In testing, we find total loss of somatic senses on the right side of the jaw, face, and tongue. This tells us that the left side of the cortex is experiencing the bleeding from an artery. She recognizes when things are in her right hand but cannot distinguish what they are without looking at them. This tells is that parts of the primary somatosensory area and the somatosensory association area of the cortex have been damaged. The left side of her body seems to be working properly and both legs, therefore the right side of her brain did not experience the stroke and based on the motor homunculus of the cortex, the bleeding has not been exposed to the top section of the brain but seems to remain just to the left side.
Again, the motor homunculus of the cortex narrows the possible location of the bleeding by our patient displaying non-contracting paralysis of the muscles in the right jaw and face. She shows movements to be hesitant and uncoordinated from the right hand. These two symptoms of paralysis and uncoordinated movements prove the problem exists in the primary motor and pre-motor areas of the cortex. Primary motor damage causes the paralysis and pre-motor causes the uncoordinated movements. She can not move her ring finger but her handwriting is normal. These are explainable because the motor area for her fingers has been affected thus causing the signal to be blocked but her handwriting mainly belongs to wrist and arm action which is located in a slightly different, unaffected area.
She claims that she can no longer play the piano or type which indicates two things. This strengthens our theory that the pre-motor region has been damaged but also shows us how long she has gone untreated for this stroke. It takes time and practice to realize that these qualities have been lost. The longer she waits for treatment, the lower her chances of full recover become.
Spoken and written words are comprehended normally but her speech is severely impaired. This symptom points to damage of the Broca’s speech area. Here we translate sounds into forms of communication.
Based on the following areas of damage: Left side of the cortex (not on the top), Primary Somatosensory and Somatosensory association areas, Primary motor and pre-motor areas, and Broca’s speech area; We can locate the distribution of damage and project and centrally localized source of bleeding. The area highlighted below gives us an idea of the extent and source of the bleeding.
According to the diagram and corresponding vascular systems of the brain, the Middle Cerebral Artery has ruptured and the leakage has emanated from there outward.
Because of the extended time between stroke and treatment, outcome with a full recovery is not a goal to strive for. Our patient has more than likely permanently damaged the neurons of these areas and they can not be repaired or replaced by the body or by modern medicine. She will continue to live her life without piano or speed typing. From now on, her speech will always be impaired but in time will improve slightly by compensation and adaptation from the other side. Otherwise she can learn to use her left hand more dominantly and with the knowledge of her stroke take better precautions in the care of her high blood pressure.
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Basal and Squamous Cell Carcinoma:
Cause, Mechanism, and Cure
Todd Alderman
Vertebrate Physiology
April 12, 2005
To be sure that everything is held together in one glob the body needs skin. Being the largest organ in the body, it packages everything in and keeps some things out. The main purpose of skin deals with homeostasis. Contributions to this can be seen in thermoregulation, disease prevention, fluid loss, and even metabolism (through the production of Vitamin D). In order to interact with the surrounding environment the skin also has receptors to monitor outside the body for things such as temperature, movement, pressure, and sunlight exposure. Sunlight is a little different in that we don’t usually respond to it consciously unless the eyes are exposed or the skin is warmed by it. Our skin however naturally responds to sunlight. Different mechanisms are triggered, in particular, by ultraviolet light which causes deviation from normal skin. Although the body usually prevents these changes naturally, if we abuse the system, UV light will have its way with us. In light of this phenomenon our skin develops cancer. The following will be a discussion on how Basal cell and Squamous cell carcinoma is initiated, the cells involved in the course of the disease, and what can now be done to cure it.
The epidermis, the top layer of skin is where we will begin. It consists mainly of four types of cells (8). Melanocytes are the major contributors of pigment in skin. These form a facing at the base of the epidermis that distinguishes it from the underlying dermis. Melanocytes produce melanin (pigment). It is then passed on to the keratinocytes which are what is seen on the surface. Melanin is particularly present in the extremities and the nipples presenting a darkened area from the rest of the body. In addition the melanin, keratinocytes contain keratin (pigment) which also contributes to the yellow-orange complexion of the skin. Examples of this are more pronounced in people of Asian origin. Keratinocytes fill in the majority of the epidermis and are constantly pushed outward and sloughed off the surface. Merkel cells are randomly interspersed throughout the melanocyte layer for communication. At each merkel cell is a neuron in the dermis that receives information to pass into the body for processing. Much of our topic will deal with the Langerhans cells. Located sparingly, compared to the others, throughout the epidermis, Langerhans cells deal with the affects of ultraviolet light in the skin. As if in retaliation, these become the target of UV light because, “-UV inhibits their antigen-presenting activity and their capacity to stimulate—T cells,” therefore hindering the restoration process (1).
Our sun produces a full spectrum of light from visible to the deadly radiations unseen by the naked eye. In dealing with skin cancer, ultraviolet A, B, and C radiation are of main concern. UVC is the most dangerous of the three. With its high energy and short wavelengths (100-290 nm), the potential for carcinogenesis becomes substantially elevated (10,12). Fortunately, for now, our ozone fully blocks these death rays. UVA, while having the longest wavelengths (315-400 nm) and the lowest energy are the deepest penetrating (10,12). These generally do not cause skin cancer. However sunlight contains twenty times more UVA than UVB. UVA does not penetrate DNA well and therefore can not directly cause carcinogenic mutations. What it can do is penetrate other molecules causing radicals, like oxygen, that will damage DNA and membranes. Connective tissue is also damaged promoting early aging affects such as dark spots and leathery texture. UVA is the radiation preferred by the best tanning bulbs! At last we come to UVB radiation…the major contributor to carcinogenesis. At wavelengths of 280-315 nm, it comes equipped with the high energy attributes of the UVC complemented by some penetrating effects from the UVA (10,12). The UVB only contacts the top layers of the epidermis and what it contacts is affected greatly because of the high energy that it packs. This light is the cause of skin cancer.
Our process begins when UV light contacts our skin. The radiation penetrates into DNA and alters the proteins. More specifically, it tends to target the sequence of two thymines and join them generating a thymine dimer (11). These dimers produce several mutations in DNA sequences that ultimately distort cellular composition. One particular change is in the gene that encodes for tumor suppression (p16). This gene is what controls cell growth rate and multiplication. “--Overerexpression of oncogenes and other genes related to enhanced growth—and tissue invasion” occurs (2). When these become damaged or altered the cells are allowed to grow without restriction. Unregulated growth gives rise to a tumor. This is the definition of cancer.
Another possible pathway, more common through exposure to UVA light, is the creation of free radicals in oxygen. These highly reactive scavenging oxygens will sometimes react directly with DNA to interfere with protein synthesis. More commonly the radicals interacted with xanthone analogues that cleave “—specifically at 5’-G of the GG sequence—,” in DNA, thus mutating cellular functions (3).
The very second that UV radiation hits the keratinocytes of the top layers of skin, the immune system will respond. Some studies have shown that hair follicles are “—specialised UV receptor[s] in the skin responding to nuances of photic input” (4). This is because the follicle consists of melanocytes and keratinocytes that are arranged similarly to that of industrial fiber optic cable. This allows a concentrated signal to be received in order to trigger expeditious immune responses. The receptors are activated to begin the immune system’s correctional steps. DNA will then elevate the production of the p53 gene. The wild type of p53, in particular, is the cause of the corrections, thus it has to be mutated by the radiation in order to begin restoration. In a case study done in 1998 two processes were discovered to be possible based on the amount of radiation exposure which directly determines the amount of p53 produced (5).
Under low-dose radiation, p53 (wild type) is found to promote nucleotide excision repair. This is done by taking out the thymine dimers from the sequence that are corrupting production. Langerhans cells now step in using specialized receptor and detect the compromised DNA sequences. These Langerhans cells phagocytize the dimers and migrate to the lymph nodes. Here the dimers are released to be discarded and the Langerhans cell returns to the epidermis. Over time this process will return the cells to their original make-up and the immune system is victorious. All “—UV radiation is known to result in epidermal thickening and increase the number of cell layers—” but returns to normal after a few days (9).After a full day in the sun one can notice that the skin seems more taut due to the increased activity in the epidermis. The increase in the number of cells allows the response to become more effective and the return to normal more rapid.
In the case of high-dose radiation, the p53 (still wild type) takes on a different strategy. Discovering the overwhelming DNA corruption due to high dosage, p53 instigates apoptosis. It utilizes this action to prevent this cell from replicating and creating more problems. It is easier to destroy the leader before he has any followers. The interesting point is that the corrupted leader kills itself for the sake of the organism. Keratinocytes naturally migrate up towards the surface through slow cell death in order to create a smooth flattened layer on the outside. This process takes several weeks. In the case of apoptosis, these cells are raised to the surface in 48-72 hours so as to export these mutants from the body. If it has not become apparent yet, this is called peeling. Again the body triumphs over solar insults. In the cases of repairs or apoptosis, once the epidermis is returned to normal p53 production is decreased to normal levels.
As humans are naturally prone to do, we tend to push our system to the limits. The body can only take so much exposure to the sun before the system looses repair efficiency. In this event the ultraviolet radiation inactivates the p16 tumor-suppressor gene. The cell no longer has a pathway to apoptosis thus p53 cannot successfully achieve its goal and a tumor is born. Langerhans cells still have some success in seeking these small tumors out and consuming them. If Langerhans cells become overwhelmed they shut down. This causes a snowball effect for the rest of the understaffed Langerhans cell. Now the tumor has grown beyond any regulation by the body and outer visibility is possible.
These tumors have an overabundance of Hedgehog proteins. Without getting into a soap opera of genes, let me explain what these accomplish. During embryological development Hedgehog proteins decide how an organism is going to grow. Specifics such as anterior/posterior orientation and limb-buds are decisions controlled by the signaling molecules of the Sonic Hedgehog Signaling Pathway (2). In the case of basal cell carcinoma, this pathway has become irreversibly activated allowing growth to become erratic.
Skin cancer boasted one million cases for 2002 in the United States alone (2). In Australia cases were increased by 51% from 1985-1990. The United Kingdom experienced a 66% increase from 1988-1998 (2). There are three major forms of skin cancer that can be described. Melanoma is one of the worst types. Fortunately it only constitutes 4% of all cases reported. This one acts differently from the second two which are discussed in this paper. Basal cell carcinoma is responsible for 80% of all skin cancer patients. Although this is a high number, basal cell has the best cure rate. Most cases are found on the head and neck. Here a spot of raised flesh or a pinkish nodule is seen with a pearly, translucent rim. The process of forming this nodule may take many months or years for one to reach a diameter of one half inch. This cancer is more common to ages of 40+. Basal cell carcinoma is rarely metastasized making it less threatening to the entire body. Squamous cell carcinoma, on the other hand, is a little more prone to metastasize into cells in different areas of the body. Because of this they can be seen on parts of the body not exposed to UV. Their origins are on the face and ears. These form just above the basal layer of the skin and boast 16% of all skin cancer cases. Cases are most common from ages 55+. Records show approximately 2,000 deaths per year are due to basal cell contributions. In comparing the last two carcinomas, the basal cell comes out ahead with a 5:1 ratio from squamous cell. Both are manufactured by UV radiation in the same way but react in different areas of the epidermis. Men are twice as likely to develop squamous as women.
Once the patient is diagnosed with basal or squamous cell carcinoma the options for curing it usually consist of removal in some form (6). Cryotherapy is used to freeze the lesion with liquid nitrogen. Once the dead cells blister and crust off, a scar will always remain. This however is not used for recurrent carcinoma. Curretage/electrodessication involves two or three sessions of scraping the cancer cells off and using an electric needle to destroy the remaining cancer. This will also leave a scar after treatment. It is still not recommended for recurrent carcinomas. Moh’s micrograph surgery has the best cure rate for difficult treat carcinomas. It is the treatment of choice for patients with recurrent skin cancer. This is a painstaking process, is very time consuming and is only performed by specialists (meaning more expensive also). It involves taking off a thin layer if skin and immediately looking at it under the microscope to check for cancer cells. If present, then the doctor will continue with another layer until the cells are absent. By doing this the scar is reduced too because of the careful attention spent on salvaging the normal skin cells. Radiation and chemotherapy are also options. These are used more in the case of squamous cells that have metastasized and are not accessible from the surface. In some cases even lymph node surgery may be required. All treatments have basically equal success rates depending on the area being treated although the scar that is left behind gives scientists reason to search for better treatments that allow the patient to return to their original appearance without draining the nest egg.
In analyzing different treatment options doctors discover new details into the mechanisms by which the body’s immune system defends against tumorigenesis. An Australian study stated that patients on immunosuppressive drugs are at much higher risk of developing skin cancer. “ -–the cumulative incidence of developing skin cancer in renal transplant patients increased progressively from 7% after one year of immunosuppression to 45% after eleven years and to as high as 70% after twenty years of immunosuppression” (2). This emphasizes the contribution of our immune system against skin cancer. In looking at the Langerhans cells again scientists have discovered that T helper cells directly assist them in removal of the damaged cells after a tumor has become present. These can be broken down into interferon-γ and interleukins. Recognized as secreting cytokines, these cells are the main defense once a tumor has begun. They have even been known to cause spontaneous regression of skin cancer without outside influence. They directly “interfere” with cell replication and, through the immune system, are somehow directed at tumor cells. Keratinocytes also release small amounts of cytokines that assisted with regression. By applying this knowledge to breakthroughs in modern medicine, scientists have been able to synthetically reproduce these cytokines in attempts to cure skin cancer.
At the University of Maryland School of Medicine, a study was conducted in 2003 using two strategies to instigate regression of tumors in basal cell carcinoma. Intralesional injections of synthetically produced interferon was one method studied, and was first attempted with success in 1986 by Dr. Greenway (2). Since that time many cases have also had success. There are many disadvantages to this treatment. “Side affects include local pain, swelling, erythema, and flu-like symptoms-.” Treatments are long and must be administered five times per week making it costly in time and money. Outcomes from this treatment still have not reached the success rate of current options without some surgical procedure. Also “-there has been no definitive large-scale studies that have determined the initial and long-term efficacy of this treatment-.”
Five percent Imiquimod was the other treatment that was tested for regression of tumors. This is applied topically in the form of a cream that gives the overall immune system a boost. It induces the synthesis of interferon from the Langerhan’s cells and tumor necrosis factor from the keratinocytes. “Imiquimod enhances the migration of Langerhan’s cells to the regional lymph node, potentially enhancing the antigen presentation to the T cells. The mechanism of the Imiquimod causes tumor regression secondarily. As seen in the diagram below, Imiquimod matures the Langerhan’s cells so they can activate T cells which will secrete the interferon-γ and interleukins to destroy the tumor (2).
By applying different doses the outcomes were varied. Groups were also treated in different time spans. Outcomes base on Table 1 describe the highest frequency of applications as the most successful. Skin reactions, however, were also experienced when applied twice a day. The best results without complications proved to be application once a day for up to twelve weeks depending on severity. The results also displayed a higher success rate if the cream was applied under the occlusion but was even more sensitive to high frequency applications (2).
Even though Imiquimod still has a lower tumor regression rate than current conventional methods, it still had much success in the market today. It is used as an assistant to the surgical procedures to present a better aesthetic result. Studies show that by using Imiquimod before surgery will reduce the size of the tumor. This will allow doctors to lessen their incision and minimize the size and severity of scar tissue. Small steps in the search for a cure will prove, over time, to present significant results.
To recognize the potential harm from basal or squamous cell carcinomas can help in taking the correct precautionary measure to stop the cycle before it begins. Certain people have genetic dispositions which make them more prone to develop these cancers. Type I skin is described as always burned and never capable of holding a tan. Also people with red/blond hair or blue/green eyes have been reported as more likely to develop skin cancer (2). Previous patients of skin cancer have a high risk of recurrent development. “It has been proposed that the risk of developing BCC is associated with severe sunburn in childhood and that there is a higher risk for those with increased recreational sunlight exposure in childhood and adolescence.” Where a person lives will also determine the amount of UV light absorbed on a daily basis. Sunscreen…wear it!! All these factors, when considered for a healthy lifestyle can contribute to a longer, more enjoyable life.
A professor once told me that basal or squamous cell carcinoma is described as, “the best of the worst.” Many cases are diagnosed every day and every day most of these are removed with complete success. Improvements are constantly made in treatment of these and other cancers. Pathways and mechanisms for cancer are still so vast that scientists are overwhelmed with the information and have difficulty collating it to produce a feasible solution. Until that day prevention is still the most effective cure.
Our skin has astonishing adaptive qualities. It can recognize changes in the environment and accommodate the interior to better efficiency. Even when overrun by UV radiation, the skin fights back to maintain control over the detriments of mutation. Its very function is to protect the body and sustain homeostasis. By moderation of exposure to ultraviolet light, we can provide our skin the opportunity to maximize its ability without compromising our immune system.
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