EDI Project: Science and Technology

LUNG CANCER

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Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. These abnormal cells do not carry out the functions of normal cells and do not develop into healthy lung tissue. As they grow, the abnormal cells can form tumors and impede the function of the lung, which is to provide oxygen to the body via the blood.

The Genetic Basis of Lung Cancer
All cells in the body contain DNA. Every time a mature cell divides into two daughter cells, it replicates its DNA exactly. The daughter cells are clones of the original cell, identical in every way. It is in this way that our bodies continually replenish themselves. Old cells die off and the next generation takes their place.
A cancer begins with an error, or mutation, in a cell's DNA. DNA mutations can be caused by the normal aging process or through environmental factors, such as cigarette smoke or breathing in asbestos.

Lung Cancer Statistics
Lung cancer is one of the most common cancers. It is the second most diagnosed cancer in men and women (after prostate and breast, respectively), but it is the number one cause of death from cancer each year in both men and women. Because lung cancer can take years to develop, it is mostly found in older people. The average age of a person receiving a lung cancer diagnosis is 69 years.
Overall, lung cancer affects men more than women, but that gap is closing.
Cigarette smoking is the cause of most lung cancers, but there are other factors, too. Exposure to asbestos, radon, environmental factors, or secondhand smoke can cause lung cancer. There are often internal factors (inherited or from our genes) as well as external or environmental factors (from outside of our bodies) involved in the development of any type of cancer.
Lung Cancer Symptoms
The signs and symptoms of lung cancer can take years to develop and they may not appear until the disease is advanced.

Some symptoms of lung cancer that are in the chest:
Intense coughing
Pain in the chest, shoulder, or back
A change in color or volume of sputum
Shortness of breath
Changes in the voice or being hoarse
Recurrent lung problems, such as bronchitis or pneumonia
Coughing up phlegm or mucus, especially if it is tinged with blood
Coughing up blood
If the original lung cancer has spread, a person may feel symptoms in other places in the body. Common places for lung cancer to spread include other parts of the lungs, lymph nodes, bones, brain, liver, and adrenal glands.

Some symptoms of lung cancer that may occur elsewhere in the body:
Loss of appetite or unexplained weight loss
Fatigue
Headaches, bone or joint pain
Bone fractures not related to accidental injury
Neurological symptoms, such as memory loss
General weakness
If you are at risk for developing lung cancer
If you are a current or former smoker, have been exposed to asbestos, radon, other environmental factors, secondhand smoke, or have a family member who developed lung cancer but who did not have those risk factors, then you may be at increased risk of developing lung cancer.
If you are at risk of developing lung cancer, the most important thing you can do is to quit smoking (if you smoke). Because smoking can cause cancers other than lung cancer, such as cancers of the esophagus, pancreas, larynx, bladder, and others, stopping smoking will reduce your risk of developing those cancers, too. Research shows that smoking cessation has many benefits that are apparent soon after quitting, such as lowered blood pressure and increased lung capacity. Depending on how long and how much you smoked, quitting may not completely erase your risk of developing lung cancer, but it will definitely reduce the risk.
Because environmental factors other than smoking can increase your risk of lung cancer, it is important to reduce or eliminate those factors. Examples of environmental factors include asbestos, radon, and secondhand smoke. If you have been exposed to asbestos or radon, you can take steps to decrease or eliminate those exposures.
If you have lung cancer
Even if you have been diagnosed with lung cancer, lifestyle changes can help you manage symptoms of the disease and your treatment.
Smoking causes the majority of lung cancers. By quitting smoking, you can immediately gain some benefits from enhanced circulation, lowered blood pressure, and increased lung function. These benefits will help your body better tolerate and heal from surgery, chemotherapy, or radiation treatment.

Types of Treatment
Surgery
Curative surgery: The removal of a tumor when it appears to be confined to one area, which means an early stage cancer. This type of surgery aims to completely remove the cancerous tumor, and may include remove a wedge, a lobe, or an entire lung.
Palliative surgery: The goal of this surgery is to make the patient more comfortable, e.g., laser surgery for the removal of an obstruction or opening of an airway.
Chemotherapy : Chemotherapy uses strong chemicals or drugs to kill cancer cells, stop their reproduction, or slow their growth.
Radiation: Radiation therapy (also called radiotherapy) may be effective for the treatment of lung cancer. It uses high-energy rays, similar to X-rays, but stronger, to kill or shrink cancer cells.

ORGAN SYSTEM

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ENDOCRINE

Role: To produce hormones that regulate the body's growth, metabolism, and sexual development and function. The hormones are released into the bloodstream and transported to tissues and organs throughout the body.

Organs: Ovaries and Testicles, Pancreas, Parathyroid glands, Pineal body, Pituitary Gland, Thymus Gland, Thyroid Gland, Adrenal Glands, Hypothalamus.

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NERVOUS

Role: To relay electrical signals through the body. It directs behavior and movement and, along with the endocrine system, control psychological processes such as digestion, circulation, etc..

Organs: Brain, spinal cord and peripheral nerves.

2008-10-24T08:32:00.000-07:00

EXCRETORY

Role: To filter out cellular wastes, toxins, and excess water or nutrients from the circulatory system.

Organs: Kidneys, ureters, bladder and urethra, skin.

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LYMPHATIC

Role: To destroy and remove invading microbes and viruses from the body. The lymphatic system also removes fat and excess from the blood.

Organs: Lymph (fluid), lymph nodes and vessels, white blood cells, T- and B-cells.

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REPRODUCTIVE

Role: To manufacture cells that allow reproduction. In the male, sperms are created to inseminate egg cells produced in the female.

Organs: Female: ovaries, oviducts, uterus, vagina and mammary glands. Male: testicles, seminal vesicles and pennies.

THE INTERNET

2008-10-21T08:54:00.000-07:00

Internet History

The conceptual foundation for creation of the Internet was significantly developed by three individuals and a research conference, each of which changed the way we thought about technology by accurately predicting its future:
Vannevar Bush wrote the first visionary description of the potential uses for information technology with his description of the "memex" automated library system.
Norbert Wiener invented the field of Cybernetics, inspiring future researchers to focus on the use of technology to extend human capabilities.
The 1956 Dartmouth Artificial Intelligence conference crystallized the concept that technology was improving at an exponential rate, and provided the first serious consideration of the consequences.
Marshall McLuhan made the idea of a global village interconnected by an electronic nervous system part of our popular culture.

In 1957, the Soviet Union launched the first satellite, Sputnik I, triggering US President Dwight Eisenhower to create the ARPA agency to regain the technological lead in the arms race. ARPA appointed J.C.R. Licklider to head the new IPTO organization with a mandate to further the research of the SAGE program and help protect the US against a space-based nuclear attack.

Licklider evangelized within the IPTO about the potential benefits of a country-wide communications network, influencing his successors to hire Lawrence Roberts to implement his vision.

Roberts led development of the network, based on the new idea of packet switching discovered by Paul Baran at RAND, and a few years later by Donald Davies at the UK National Physical Laboratory. A special computer called an Interface Message Processor was developed to realize the design, and the ARPANET went live in early October, 1969. The first communications were between Leonard Kleinrock's research center at the University of California at Los Angeles, and Douglas Engelbart's center at the Stanford Research Institute.

The first networking protocol used on the ARPANET was the Network Control Program. In 1983, it was replaced with the TCP/IP protocol developed by Robert Kahn, Vinton Cerf, and others, which quickly became the most widely used network protocol in the world.

In 1990, the ARPANET was retired and transferred to the NSFNET. The NSFNET was soon connected to the CSNET, which linked Universities around North America, and then to the EUnet, which connected research facilities in Europe. Thanks in part to the NSF's enlightened management, and fueled by the popularity of the web, the use of the Internet exploded after 1990, causing the US Government to transfer management to independent organizations starting in 1995.

And here we are.

BASIC PARTS ON A CELL

2008-10-21T08:49:00.000-07:00

Cell Membrane (also known as plasma membrane or plasmalemma) is surrounds all cells. It: 1) separates the inner parts of the cell from the outer environment; and 2) acts as a selectively permeable barrier to allow certain chemicals, namely water, to pass and others to not pass. In multicellular organisms certain chemicals on the membrane surface act in the recognition of self. Antigens are substances located on the outside of cells, viruses and in some cases other chemicals. Antibodies are chemicals (Y-shaped) produced by an animal in response to a specific antigen. This is the basis of immunity and vaccination.

Hereditary material (both DNA and RNA) is needed for a cell to be able to replicate and/or reproduce. Most organisms use DNA. Viruses and viroids sometimes employ RNA as their hereditary material. Retroviruses include HIV (Human Immunodefficiency Virus, the causative agent of AIDS) and Feline Leukemia Virus (the only retrovirus for which a successful vaccine has been developed). Viroids are naked pieces of RNA that lack cytoplasm, membranes, etc. They are parasites of some plants and also as possible glimpses of the functioning of pre-cellular life forms. Prokaryotic DNA is organized as a circular chromosome contained in an area known as a nucleoid. Eukaryotic DNA is organized in linear structures, the eukaryotic chromosomes, which are associations of DNA and histone proteins contained within a double membrane nuclear envelope, an area known as the cell nucleus.

Organelles are formed bodies within the cytoplasm that perform certain functions. Some organelles are surrounded by membranes, we call these membrane-bound organelles.

Ribosomes are the tiny structures where proteins synthesis occurs. They are not membrane-bound and occur in all cells, although there are differences between the size of subunits in eukaryotic and prokaryotic ribosomes.

The Cell Wall is a structure surrounding the plasma membrane. Prokaryote and eukaryote (if they have one) cell walls differ in their structure and chemical composition. Plant cells have cellulose in their cell walls, other organisims have different materials cpmprising their walls. Animals are distinct as a group in their lack of a cell wall.

Membrane-bound organelles occur only in eukaryotic cells. They will be discussed in detail later. Eukaryotic cells are generally larger than prokaryotic cells. Internal complexity is usually greater in eukaryotes, with their compartmentalized membrane-bound organelles, than in prokaryotes. Some prokaryotes, such as Anabaena azollae, and Prochloron, have internal membranes associated with photosynthetic pigments.

THE CELL

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CELL

The cell is one of the most basic units of life. There are millions of different types of cells. There are cells that are organisms onto themselves, such as microscopic amoeba and bacteria cells. And there are cells that only function when part of a larger organism, such as the cells that make up your body. The cell is the smallest unit of life in our bodies
In the body, there are brain cells, skin cells, liver cells, stomach cells, and the list goes on. All of these cells have unique functions and features. And all have some recognizable similarities.
Life exhibits varying degrees of organization. Atoms are organized into molecules, molecules into organelles, and organelles into cells, and so on. According to the Cell Theory, all living things are composed of one or more cells, and the functions of a multicellular organism are a consequence of the types of cells it has. Cells fall into two broad groups: prokaryotes and eukaryotes. Prokaryotic cells are smaller (as a general rule) and lack much of the internal compartmentalization and complexity of eukaryotic cells. No matter which type of cell we are considering, all cells have certain features in common, such as a cell membrane, DNA and RNA, cytoplasm, and ribosomes. Eukaryotic cells have a great variety of organelles and structures.

HIV

2008-10-21T08:37:00.000-07:00

DEFINITION

AIDS is the abbreviation for acquired immune deficiency syndrome. The disease is caused by a virus known as the human immunodeficiency virus, or HIV. The disease was first recognized in the United States in 1981.
A person can be infected with HIV without developing AIDS. The virus can remain in a person's body for many years without causing serious health problems. During this period, the virus is said to be latent, or inactive. Eventually, however, most people who are infected with HIV do develop AIDS. Treatment of HIV patients involves trying to slow or stop the virus from spreading in the body's cells and treating or preventing diseases that develop when a person's immune system has been damaged by the virus.

DESCRIPTION

AIDS is considered one of the most serious public health problems in modern history. In 1998 the U.S. Centers for Disease Control and Prevention (CDC) estimated that between 650,000 and 900,000 Americans were HIV-positive. HIV-positive means that a person has been infected with the virus. The CDC estimates that as of 1998 some 300,000 Americans were living with AIDS.
Nearly half of all AIDS patients are gay or bisexual men. About one quarter are intravenous drug users. About 18 percent of AIDS patients are women. In addition, between one thousand and two thousand children are born infected with HIV each year.
HIV can be transmitted in several ways:

SEXUAL CONTACT. HIV can be transmitted any time two people exchange bodily fluids, such as semen or blood. The risk of contracting the virus increases if an individual has a high number of different sexual partners or practices unsafe sex. In the United States and Europe, most cases of sexually transmitted HIV infection occur during homosexual contact.

EXPOSURE TO CONTAMINATED BLOOD OR BLOOD PRODUCTS. Early in the HIV epidemic, the virus was sometimes transmitted during blood transfusions. Blood taken from one person with the HIV infection was given to a second person for medical treatment, he or she also received the virus.
In the 1980s, new rules were adopted for the screening of donated blood. Since that time, the rate of HIV infections from contaminated blood and blood products has been greatly reduced. However, HIV infection is still spread by this method among illegal drug users. These men and women often share the same needle with each other. When they do so, the blood from one person is easily transferred to a second person. If the first person is infected with HIV, the virus may be passed on.

PREGNANCY AND BIRTH. A woman infected with HIV can transmit the virus to her unborn child. The virus passes through the amniotic fluid (the fluid surrounding the unborn baby) and into the child's bloodstream. A young baby can also get the virus from an infected woman during breast feeding.

TYPES OF HIV

HIV is a highly variable virus which mutates very readily. This means there are many different strains of HIV, even within the body of a single infected person.
Based on genetic similarities, the numerous virus strains may be classified into types.
HIV-1 and HIV-2. Both types are transmitted by sexual contact, through blood, and from mother to child, and they appear to cause clinically indistinguishable AIDS. However, it seems that HIV-2 is less easily transmitted, and the period between initial infection and illness is longer in the case of HIV-2.
Worldwide, the predominant virus is HIV-1, and generally when people refer to HIV without specifying the type of virus they will be referring to HIV-1. The relatively uncommon HIV-2 type is concentrated in West Africa and is rarely found elsewhere.
Human Immunodeficiency Virus Type 2
Both HIV-1 and HIV-2 have the same modes of transmission and are associated with similar opportunistic infections and AIDS. In persons infected with HIV-2, immunodeficiency seems to develop more slowly and to be milder. Compared with persons infected with HIV-1, those with HIV-2 are less infectious early in the course of infection. As the disease advances, HIV-2 infectiousness seems to increase; however, compared with HIV-1, the duration of this increased infectiousness is shorter.

CAUSES

AIDS develops when HIV attacks and destroys certain types of cells that are part of the immune system. The immune system consists of all those cells, tissues, and substances that protect the body from infection by foreign bodies, such as bacteria. An important element of the immune system is a group of white blood cells that include helper T cells, macrophages, and monocytes. These cells attack foreign bodies and prevent them from causing disease and infection.
After it enters the body, HIV attaches itself to a certain part of these cells called the CD4 protein. The virus then takes command of the chemical changes that take place within the cell. It orders the cell to start making copies of the HIV virus. It eventually causes the cell's death. As the cell dies, it breaks apart and releases many new copies of the HIV. The new HIV cells then travel through the bloodstream and attack other white blood cells.
As white blood cells die, the immune system becomes weaker. The body is no longer able to fight back against infection. Infections that would normally be relatively harmless, such as the common cold, can become life-threatening to someone who is HIV positive.

SYMPTOMS

A person who has been infected with HIV is likely to pass through three stages of the disease. Not all individuals experience all of the stages.
Acute Retroviral Syndrome
Acute retroviral syndrome is a term used to describe a group of symptoms that can resemble mononucleosis. Mononucleosis is a flu-like infection. Its symptoms include fever, fatigue, muscle aches, loss of appetite, upset stomach, weight loss, skin rash, headache, and swollen lymph nodes.
Latency Period
After entering a person's lymph nodes, the virus becomes latent. Latency means that the virus is still present in the body, but that there are no signs of infection. Therefore, a person may appear to be perfectly healthy even though blood tests show that the virus is present.
HIV infection has an unusually long latency period. It may last for ten years or more. During this period, the virus continues to reproduce itself in the lymph nodes. As a result, certain abnormal conditions and symptoms may develop.
Late-stage AIDS
Late-stage AIDS is the period of HIV infection when the virus has become very active and has started to cause massive damage to the immune system. One sign of late-stage AIDS is a sharp decrease in the number of white blood cells known as CD4 lymphocytes. The patient also begins to have more frequent and more serious medical problems, such as infectious diseases and cancers. The infections that occur are called opportunistic infections. That term means that foreign bodies, such as bacteria, have taken advantage of the bodies weakened immune systems.
AIDS dementia complex usually occurs late in the progress of AIDS. It is marked by loss of reasoning ability, loss of memory, inability to concentrate, listlessness, and unsteadiness in walking. Scientists do not understand how HIV causes AIDS dementia. There are no treatments for the condition.
Patients in late-stage AIDS may develop inflammation of the muscles, especially in the hip area. They may experience pain in their joints similar to those that occur with arthritis. Thrush and ulcers (open sores) in the mouth continue to occur during the late stages of AIDS. Another common condition of this stage is hairy leukoplakia of the tongue. Hairy leukoplakia is characterized by a white area on the tongue that may be flat or slightly raised.

HIV RETROVIRUS

HIV is an enveloped retrovirus. Each virus particle contains two copies of an RNA genome. The virus also has a number of enzymes: reverse transcriptase, integrase and viral protease. These molecules play an important role in making new copies of HIV and can be the targets of antiretroviral drugs. The HIV viral particle, or virion, has a capsid which is cone-shaped and is enclosed in a lipid bilayer, or envelope. This envelope contains viral glycoproteins which bind specifically to CD4 T cell receptors, enabling the virus to enter its host.
The name retrovirus comes from the fact that the RNA genome is transcribed/copied back into DNA in the host cell (by reverse transcriptase). The DNA is then incorporated into the host cell chromosome.
HIV belongs to a group of retroviruses called lentiviruses, from the Latin lentus, meaning slow, because of the gradual course of the disease they cause.