WHAT IS CANCER

Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age.^[1] Cancer causes about 13% of all deaths.^[2] According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007.^[3] Cancers can affect all animals.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers are usually affected by complex interactions between carcinogens and the host's genome. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatment

CAN WE LEARN TO STUDY MORE EFFECTIVELY

there are a range of techniques we can use to help us study more effectively.even simple actions such as changing location by moving frm the study to the living room,for example can be beneficial.the different locations in which learning takes place become recall stimuli which help the brain to consolidate knowledge.it is also important to take occasional complete breaks away frm study,such as jogging or goin for a short walk....it also helps to structure the material to be learnt.

Kissing in Western culture

In modern Western culture, kissing is most commonly an expression of affection.^[9] Between people of close acquaintance, a reciprocal kiss often is offered as a greeting or farewell.^[10] This kind of kiss is typically made by brief contact of puckered lips to the skin of the cheek or no contact at all, and merely performed in the air near the cheek with the cheeks touching.^[11] People may kiss children on the forehead to comfort them or the cheek to show affection, and vice versa.

As an expression of romantic affection or sexual desire in Western culture, kissing involves two people pressing their lips together with an intensity of sexual feeling. A couple may open their mouths, suck on each other's lips or move their tongues into each others' mouths (see French kiss). Romantic or sexual kissing may also involve kissing various parts of another's body (see Foreplay) such as the neck, the ears, the breasts, the navel, the genitals, etc.

In Eastern European countries and Slavic cultures until recent times, kissing between two men on the lips as a greeting or a farewell was not uncommon and not considered sexual.^{[citation needed]} Symbolic kissing is frequent in Western cultures. A kiss can be "blown" to another by kissing the fingertips and then blowing the fingertips, pointing them in the direction of the recipient. This is used to convey affection, usually when parting or when the partners are physically distant but can view each other. Blown kisses are also used when a person wishes to convey affection to a large crowd or audience. In written correspondence a kiss has been represented by the letter 'X' since at least 1763.^[12] A stage or screen kiss may be performed by actually kissing, or faked by using the thumbs as a barrier for the lips and turning so the audience is unable to fully see the act

DO MUSCLES WORK IN PAIRS

muscles actually work in pairs.a muscle can ony pull in one direction so it needs another muscle to pull in the opposite direction in order to return a bone to its original position.when you lift ur forearm,the biceps muscle shortens to lift the bone.when you straighten your arm,the triceps muscle pulls it back again and the biceps relaxes.the same action takes place in ur legs when you walk and run,and when you move ur fingers or toes

ANTIBIOTICS-OVERVIEW

Unlike many previous treatments for infections, which often consisted of administering chemical compounds such as strychnine and arsenic, with high toxicity also against mammals, antibiotics from microbes had no or few side effects^{[citation needed]} and high effective target activity. Most anti-bacterial antibiotics do not have activity against viruses, fungi, or other microbes. Anti-bacterial antibiotics can be categorized based on their target specificity: "narrow-spectrum" antibiotics target particular types of bacteria, such as Gram-negative or Gram-positive bacteria, while broad-spectrum antibiotics affect a wide range of bacteria.

The environment of individual antibiotics varies with the location of the infection, the ability of the antibiotic to reach the infection site, and the ability of the microbe to inactivate or excrete the antibiotic. Some anti-bacterial antibiotics destroy bacteria (bactericidal), whereas others prevent bacteria from multiplying (bacteriostatic).

Oral antibiotics are simply ingested, while intravenous antibiotics are used in more serious cases, such as deep-seated systemic infections. Antibiotics may also sometimes be administered topically, as with eye drops or ointments.

In the last few years three new classes of antibiotics have been brought into clinical use. This follows a 40-year hiatus in discovering new classes of antibiotic compounds. These new antibiotics are of the following three classes: cyclic lipopeptides (daptomycin), glycylcyclines (tigecycline), and oxazolidinones (linezolid). Tigecycline is a broad-spectrum antibiotic, while the two others are used for Gram-positive infections. These developments show promise as a means to counteract the growing bacterial resistance to existing antibiotics.

Although potent antibiotic compounds for treatment of ancient human cultures, including the ancient Egyptians, ancient Greeks and medieval Arabs already used molds and plants to treat infections, owing to the production of antibiotic substances by these organisms, a phenomenon known as antibiosis.

Quinine became widely applied as a therapeutic agent in the 17th century for the treatment of malaria, the disease caused by Plasmodium falciparum, a protozoan parasite.

Antibiosis was first described in 1877 in bacteria when Louis Pasteur and Robert Koch observed that an airborne bacillus could inhibit the growth of Bacillus anthracis. to the discovery of penicillin,The antibiotic properties of Penicillium sp. were first described in england by John Tyndall in 1875.However, his work went by without much notice from the scientific community until Alexander Fleming's discovery of Penicillin.

Modern research on antibiotic therapy began in Germany with the development of the narrow-spectrum antibiotic Salvarsan by Paul Ehrlich in 1909, for the first time allowing an efficient treatment of the then-widespread problem of Syphilis. The drug, which was also effective against other spirochaeta infections, is no longer in use in modern medicine.

Antibiotics were further developed in Britain following the discovery of Penicillin in 1928 by Alexander Fleming. More than ten years later, Ernst Chain and Howard Florey became interested in his work, and came up with the purified form of penicillin. The three shared the 1945 Nobel Prize in Medicine. In 1939, Rene Dubos isolated gramicidin, one of the first commercially manufactured antibiotics in use during World War II to prove highly effective in treating wounds and ulcers.

Prontosil, the first commercially available antibacterial antibiotic was developed by a research team led by Gerhard Domagk (who received the 1939 Nobel Prize in Physiology or Medicine for his efforts at the Bayer Laboratories of the IG Farben conglomerate in Germany). Prontosil had a relatively broad effect against Gram-positive Coccus but not against Enterobacteriaceae. The development of this first Sulfonamide drug opened the era of antibiotics.

WHY DO WE HAVE SKIN

skin is a flexible,waterproof covering tat protects us from the outside world.it prevents harmful germs frm entering the body.skin is ur largest organ and it is sensitive to touch,temperature,and pain.your skin tells you wat is happening around your body,so you can avoid injuring ur self.it also helps to prevent damage frm the sun's harmful ultraviolet rays.finally skin helps to regulate body temperature by sweating and flushing to lose heat when you get too hot....

WHY ARE VIRUSES DIFFERENT FROM BACTERIA?

both bacteria and viruses are the most important causes of diseases.bacteria are simple plant like organism tat can divide very quickly.they cause many common infections such as boils and acne.viruses are very much smaller and technically they are not alive at all.they can take over the functioning of an infected cell and turn it into a factory producing millions more viruses.viruses are responsible for many diseases even the common cold.be warned my dear friends virus cant be destroyed by medication(modern of tradisional) ony our body's antibody can destroy the virus..........

the most common of all viruses

the sweet innocent common cold

and the worst
the nasty ebola virus....tis virus basicly makes u bleed from ur eyes,nose,ears,mouth and gums......once infected by this virus ur red blood cells gets invaded by the virus this cruel process destroys red blood cells causing death to come within 2 days of infection.......

WHY IS BLOOD RED??

red blood cells contains the protein heamoglobin,which gives it its red colour.to be more precise,the haem group of proteins molecules-or even more the iron attached to them is responsible for the colour.heamoglobin's task is to bind with oxygen in the lungs,transport it to the rest of the body and then release it.to do this,the heam group enters into a loose chemical bond wit oxygen,which is easily released in surroundings where oxygen is in short supply.heamoglobin is bright red when full of oxygen.without oxygen,the molecular structure changes and with it the absorption of light tat dictates its colour.this is why blood tat is deficient in oxygen appears darker

WHY DOES OUR STOMACH RUMBLE

if some time has passed since our most recent meal,the stomach is empty or, to be more precise, it contains ony gastric juices and swallowed air.the otherwise silent,slow and regular contractions of the stomach walls become stronger and produce a gurgling sound.however these hunger contractions subside as soon as we eat something.the intestines can produce similar noises when food pulp and gas it contains are being moved steadily down its length.....ps see the gelatin capsule on the pic....ignore it