Transposon

Transposons are sequences of DNA that can move around to different positions within the genome of a single cell, a process called transposition. In the process, they can cause mutations and change the amount of DNA in the genome. Transposons were also once called jumping genes, and are examples of mobile genetic elements. They were discovered by Barbara McClintock early in her career, for which she was awarded a Nobel prize in 1983.
There are a variety of mobile genetic elements, and they can be grouped based on their mechanism of transposition. Class I mobile genetic elements, or retrotransposons, copy themselves by first being transcribed to RNA, then reverse transcribed back to DNA by reverse transcriptase, and then being inserted at another position in the genome. Class II mobile genetic elements move directly from one position to another using a transposase to "cut and paste" them within the genome.
Transposons make up a large fraction of fieciesgenome sizes which is evident through the C-values of eukaryotic species. The sheer volume of seemingly useless material initially puzzled researchers, so that it was termed "Junk DNA" until further research revealed the critical role that it played in the development of an organism. They are very useful to researchers as a means to alter DNA inside a living organism.


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What is Biochemistry

Biochemistry is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components such as proteins, carbohydrates,lipids, nucleic acids and other biomolecules.

Among the vast number of different biomolecules, many are complex and large molecules (called polymers), which are composed of similar repeating subunits (calledmonomers). Each class of polymeric biomolecule has a different set of subunit types.^[1] For example, a protein is a polymer whose subunits are selected from a set of 20 or more amino acids. Biochemistry studies the chemical properties of important biological molecules, like proteins, and in particular the chemistry ofenzyme-catalyzed reactions.

The biochemistry of cell metabolism and the endocrine system has been extensively described. Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, andsignal transduction.

Since all known life forms that are still alive today are descended from one of two common ancestors, they have generally similar biochemistries.^[2][3]

It remains unknown whether alternative types of biochemistries are possible, or practical, given thechemical elements composing the matter of the Universe. An emerging thesis, called "carbon chauvinism," holds that only carbon-based compounds are available to be part of a real biochemistry.

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What is Lupus?

Lupus is an autoimmune disease where the body's immune system becomes hyperactive and attacks normal, healthy tissue. This results in symptoms such as inflammation, swelling, and damage to joints, skin, kidneys, blood, the heart, and lungs.
Under normal function, the immune system makes proteins called antibodies in order to protect and fight against antigens such as viruses and bacteria. Lupus makes the immune system unable to differentiate between antigens and healthy tissue. This leads the immune system to direct antibodies against the healthy tissue - not just antigens - causing swelling, pain, and tissue damage.
(* An antigen is a substance capable of inducing a specific immune response.)

What are the different types of lupus?

Several different kinds of lupus have been identified, but the type that we refer to simply as lupus is known as systemic lupus erythematosus or SLE. Other types include discoid (cutaneous), drug-induced, and neonatal.

photo © St Thomas' Lupus Trust

Patients with discoid lupus have a version of the disease that is limited to the skin. It is characterized by a rash that appears on the face, neck, and scalp, and it does not affect internal organs. Less than 10% of patients with discoid lupus progress into the systemic form of the disease, but there is no way to predict or prevent the path of the disease. SLE is more severe than discoid lupus because it can affect any of the body's organs or organ systems. Some people may present inflammation or other problems with only skin and joints, while other SLE sufferers will see joints, lungs, kidneys, blood, and/or the heart affected. This type of lupus is also often characterized by periods of flare (when the disease is active) and periods of remission (when the disease is dormant).
Drug-induced lupus is caused by a reaction with certain prescription drugs and causes symptoms very similar to SLE. The drugs most commonly associated with this form of lupus are a hypertension medication called hydralazine and a heart arrhythmia medication called procainamide, but there are some 400 other drugs that can also cause the condition. Drug-induced lupus is known to subside after the patient stops taking the triggering medication.
A rare condition, neonatal lupus occurs when a mother passes autoantibodies to a fetus. The unborn and newborn child can have skin rashes and other complications with the heart and blood. Usually a rash appears but eventually fades within the first six months of the child's life.

Who is affected by lupus?

According to the Lupus Foundation of America (LFA), 1.5 to 2 million Americans have some form of lupus. The prevalence is about 40 cases per 100,000 persons among Northern Europeans and 200 per 100,000 persons among blacks. Although the disease affects both males and females, women are diagnosed 9 times more often than men, usually between the ages of 15 and 45. African-American women suffer from more severe symptoms and a higher mortality rate.
Other risk factors include exposure to sunlight, certain prescription medications, infection with Epstein-Barr virus, and exposure to certain chemicals.

What causes lupus?

Although doctors are do not know exactly what causes lupus and other autoimmune diseases, most believe that lupus results from both genetic and environmental stimuli.
Since lupus is known to occur within families, doctors believe that it is possible to inherit a genetic predisposition to lupus. There are no known genes, however, that directly cause the illness. It is probable that having an inherited predisposition for lupus makes the disease more likely only after coming into contact with some environmental trigger.
The higher number of lupus cases in females than in males may indicate that the disease can be triggered by certain hormones. Physicians believe that hormones such as estrogen regulate the progression of the disease because symptoms tend to flare before menstrual periods and/or during pregnancy.
Certain environmental factors have been known to cause lupus symptoms. These include:

• Extreme stress
• Exposure to ultraviolet light, usually from sunlight
• Smoking
• Some medications and antibiotics, especially those in the sulfa and penicillin groups
• Some infections, such as cytomegalovirus (CMV), parvovirus (such as fifth disease), hepatitis C infections, and the Epstein-Barr virus (in children)
• Chemical exposure to compounds such as trichloroethylene in well water and dust

What are the symptoms of lupus?

Since no two cases of lupus are exactly alike, there is a wide range of symptoms that are known to affect many parts of the body. Sometimes symptoms develop slowly or appear suddenly; they can be mild, severe, temporary, or permanent. Most people with lupus experience symptoms in only a few organs, but more serious cases can lead to problems with kidneys, the heart, the lungs, blood, or the nervous system.
Lupus episodes, or flares, are usually noted by a worsening of some of the following symptoms:

• Achy joints (arthralgia), arthritis, and swollen joints, especially in wrists, small joints of the hands, elbows, knees, and ankles
• Swelling of the hands and feet due to kidney problems
• Fever of more than 100 degrees F (38 degrees C)
• Prolonged or extreme fatigue
• Skin lesions or rashes, especially on the arms, hands, face, neck, or back
• Butterfly-shaped rash (malar rash) across the cheeks and nose
• Anemia (oxygen carrying deficiency of red blood cells)
• Pain in the chest on deep breathing or shortness of breath
• Sun or light sensitivity (photosensitivity)
• Hair loss or alopecia
• Abnormal blood clotting problems
• Raynaud's phenomenon: fingers turn white and/or blue or red in the cold
• Seizures
• Mouth or nose ulcers
• Weight loss or gain
• Dry eyes
• Easy bruising
• Anxiety, depression, headaches, and memory loss

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What is Obesity?

An obese person has accumulated so much body fat that it might have a negative effect on their health. If a person's bodyweight is at least 20% higher than it should be, he or she is considered obese. If your Body Mass Index (BMI) is between 25 and 29.9 you are considered overweight. If your BMI is 30 or over you are considered obese.

What is Body Mass Index (BMI)?

The BMI is a statistical measurement derived from your height and weight. Although it is considered to be a useful way to estimate healthy body weight, it does not measure the percentage of body fat. The BMI measurement can sometimes be misleading - a muscleman may have a high BMI but have much less fat than an unfit person whose BMI is lower. However, in general, the BMI measurement can be a useful indicator for the 'average person'.

Body Mass Index Calculator
cm/kgin/lb
Height:
Weight:
BMI =

*note: this body mass index calculator is provided for guide purposes only

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Why do people become obese?

People become obese for several reasons, including:

1. Consuming too many calories.
   People are eating much more than they used to. This used to be the case just in developed nations - however, the trend has spread worldwide. Despite billions of dollars being spent on public awareness campaigns that attempt to encourage people to eat healthily, the majority of us continue to overeat. In 1980 14% of the adult population of the USA was obese; by 2000 the figure reached 31% (The Obesity Society).
   
   In the USA, the consumption of calories increased from 1,542 per day for women in 1971 to 1,877 per day in 2004. The figures for men were 2,450 in 1971 and 2,618 in 2004. Most people would expect this increase in calories to consist of fat - not so! Most of the increased food consumption has consisted of carbohydrates (sugars). Increased consumption of sweetened drinks has contributed significantly to the raised carbohydrate intake of most young American adults over the last three decades. The consumption of fast-foods has tripled over the same period.
   
   Various other factors also may have contributed to America's increased calorie and carbohydrate intake:
   
   
   • In 1984 the Reagan administration freed up advertising on sweets and fast foods for children - regulations had previously set limits.
   • Agricultural policies in most of the developed world have led to much cheaper foods.
   • The US Farm Bill meant that the source of processed foods came from subsidized wheat, corn and rice. Corn, wheat and rice became much cheaper than fruit and vegetables.
2. Leading a sedentary lifestyle.
   With the arrival of televisions, computers, video games, remote controls, washing machines, dish washers and other modern convenience devices, the majority of people are leading a much more sedentary lifestyle compared to their parents and grandparents. Some decades ago shopping consisted of walking down the road to the high street where one could find the grocers, bakers, banks, etc. As large out-of-town supermarkets and shopping malls started to appear, people moved from using their feet to driving their cars to get their provisions. In some countries, such as the USA, dependence on the car has become so strong that many people will drive even if their destination is only half-a-mile away.
   
   The less you move around the fewer calories you burn. However, this is not only a question of calories. Physical activity has an effect on how your hormones work, and hormones have an effect on how your body deals with food. Several studies have shown that physical activity has a beneficial effect on your insulin levels - keeping them stable. Unstable insulin levels are closely associated with weight gain.
3. Not sleeping enough.
   If you do not sleep enough your risk of becoming obese doubles, according to research carried out at Warwick Medical School at the University of Warwick. The risk applies to both adults and children. Professor Francesco Cappuccio and team reviewed evidence in over 28,000 children and 15,000 adults. Their evidence clearly showed that sleep deprivation significantly increased obesity risk in both groups.
   
   Professor Cappuccio said, "The 'epidemic' of obesity is paralleled by a 'silent epidemic' of reduced sleep duration with short sleep duration linked to increased risk of obesity both in adults and in children. These trends are detectable in adults as well as in children as young as 5 years."
   Professor Cappuccio explains that sleep deprivation may lead to obesity through increased appetite as a result of hormonal changes. If you do not sleep enough you produce Ghrelin, a hormone that stimulates appetite. Lack of sleep also results in your body producing less Leptin, a hormone that suppresses appetite.
4. Endocrine disruptors, such as some foods that interfere with lipid metabolism.
   A team from the University of Barcelona (UB) led by Dr Juan Carlos Laguna published a study in the journal Hepatology that provides clues to the molecular mechanism through which fructose (a type of sugar) in beverages may alter lipid energy metabolism and cause fatty liver and metabolic syndrome.
   
   Fructose is mainly metabolized in the liver, the target organ of the metabolic alterations caused by the consumption of this sugar. In this study, rats receiving fructose-containing beverages presented a pathology similar to metabolic syndrome, which in the short term causes lipid accumulation (hypertriglyceridemia) and fatty liver, and eventually leads to hypertension, resistance to insulin, diabetes and obesity.
   
   Poorly balanced diets and the lack of physical exercise are key factors in the increase of obesity and other metabolic diseases in modern societies. In epidemiological studies in humans, the effect of the intake of fructose-sweetened beverages also seems to be more intense in women. (From - "New Data On Fructose-Sweetened Beverages And Hepatic Metabolism").
   
   Although there appears to be a consensus on the negative effects of fructose-sweetened beverages there is still some debate over the effects of fructose versus high fructose corn syrup - two studies of note are:
   "AMA Finds High Fructose Syrup Unlikely To Be More Harmful To Health Than Other Caloric Sweeteners" and "Fructose Sweetened Drinks Increase Nonfasting Triglycerides In Obese Adults".
5. Lower rates of smoking (smoking suppresses appetite).
   According to the National Institutes of Health (NIH) "Not everyone gains weight when they stop smoking. Among people who do, the average weight gain is between 6 and 8 pounds. Roughly 10 percent of people who stop smoking gain a large amount of weight - 30 pounds or more."
6. Medications that make patients put on weight.
   According to an article in Annals of Pharmacotherapy, some medications cause weight gain. "Clinically significant weight gain is associated with some commonly prescribed medicines. There is wide interindividual variation in response and variation of the degree of weight gain within drug classes. Where possible, alternative therapy should be selected, especially for individuals predisposed to overweight and obesity." (The Annals of Pharmacotherapy: Vol. 39, No. 12, pp. 2046-2054. DOI 10.1345/aph.1G33)

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What Is The Pancreatic Cancer

The pancreas is a 6-inch long organ located behind the stomach in the back of the abdomen. It is spongy and shaped somewhat like a fish, extended horizontally across the abdomen. The head of the pancreas is on the right side of the abdomen where the stomach is attached to the first part of the small intestine (the duodenum). The tail of the pancreas - its narrowest part - extends to the left side of the abdomen next to the spleen.
The pancreas contains exocrine and endocrine glands that create pancreatic juices, hormones, and insulin. Pancreatic juices, or enzymes, made by the exocrine glands are released into the intestines by way of a series of ducts in order to help digest fat, proteins, and carbohydrates. Over 95% of the pancreas is made up of exocrine glands and ducts. The endocrine cells are arranged in small clusters called islets of Langerhans, which release insulin and glucagon into the bloodstream. These two hormones manage levels of sugar in the blood. When they are not working properly, the result is often diabetes.
More information on the pancreas itself is available in our article What Is The Pancreas? What Does The Pancreas Do?

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What Is Pancreatic Cancer?

Cancer is a class of diseases characterized by out-of-control cell growth, and pancreatic cancer occurs when this uncontrolled cell growth begins in the pancreas. Rather than developing into healthy, normal pancreas tissue, these abnormal cells continue dividing and form lumps or masses of tissue called tumors. Tumors then interfere with the main functions of the pancreas. If a tumor stays in one spot and demonstrates limited growth, it is generally considered to be benign.

More dangerous, or malignant, tumors form when the cancer cells migrate to other parts of the body through the blood or lymph systems. When a tumor successfully spreads to other parts of the body and grows, invading and destroying other healthy tissues, it is said to have metastasized. This process itself is called metastasis, and the result is a more serious condition that is very difficult to treat.

In the United States each year, over 30,000 people are diagnosed with pancreatic cancer. Europe sees more than 60,000 diagnoses each year. Because pancreatic cancer is usually diagnosed late into its development, the five-year survival rate after diagnosis is less than 5%.

How Is Pancreatic Cancer Classified?

 

Pancreatic cancer is categorized depending on whether it affects the exocrine or endocrine functions of the pancreas. There is an important distinction between the two broad types of pancreatic cancer because they have different risk factors, causes, symptoms, diagnostic tests, treatments, and prognoses.

Tumors that affect the exocrine functions are the most common type of pancreatic cancer. Sometimes these tumors or cysts are benign, called cystadenomas. However, it is more likely to find malignant tumors called adenocarcinomas, which account for 95% of exocrine pancreatic cancers. Adenocarcinomas typically start in gland cells in the ducts of the pancreas, but they can also arise from pancreatic enzyme cells (acinar cell carcinoma).
Other types of pancreatic cancers that are associated with exocrine functions include adenosquamous carcinomas, squamous cell carcinomas, and giant cell carcinomas, named for their appearances underneath a microscope. There is also a disease called ampullary cancer (carcinoma of the ampulla of Vater) that starts where the bile duct and pancreatic duct meet the duodenum of the small intestine.
Tumors that affect the endocrine functions of the pancreas are called neuroendocrine or islet cell tumors, but these are fairly uncommon. These tumors are named for the type of hormone-producing cell that is initially affected. For example: insulinomas (insulin), glucagonomas (glucagon), gastrinomas (gastrin), somatostatinomas (somatostatin), and  VIPomas (vasoactive intestinal peptide or VIP). Functioning islet cell tumors still make hormones, while non-functioning ones do not. Most of these tumors are benign, but non-functioning tumors are more likely to be malignant, islet cell carcinomas.

What Causes Pancreatic Cancer?

Cancer is ultimately the result of cells that uncontrollably grow and do not die. Normal cells in the body follow an orderly path of growth, division, and death. Programmed cell death is called apoptosis, and when this process breaks down, cancer results. Pancreatic cancer cells do not experience programmatic death, but instead continue to grow and divide. Although scientists do not know exactly what causes these cells to behave this way, they have identified several potential risk factors.

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What is body dysmorphic disorder?

What is body dysmorphic disorder? Body dysmorphic disorder, or BDD, is an obsessive-compulsive spectrum disorder in which an individual is preoccupied with a greatly exaggerated or completely imagined defect in their appearance. Concerns of body dysmorphic disorder typically are focused around the head and face, e.g., shape or size of one's nose. For signs and symptoms and symptoms of body dysmorphic disorder, visit our body dysmorphic disorder symptoms page.

Many people who suffer from body dysmorphic disorder become so concerned with one aspect of their appearance that it becomes difficult to engage in activities, such as going outside, going to work, or engaging in normal social functions. Thoughts on their perceived flaw(s) become all consuming.

Body dysmorphic disorder affects one in fifty people. It typically starts in the teenage years or early twenties.

Body dysmorphic disorder can lead to other psychiatric problems, such as depression. It also can co-exist with disorders such as OCD, anxiety disorders, trichotillomania and eating disorders.

Because many of those afflicted with body dysmorphic disorder feel ashamed, or do not recognize that they need help, it can be difficult to diagnose. Fortunately, treatment can help return those suffering from body dysmorphic disorder to a normal life. If you think you or someone you know may be suffering fron body dysmorphic disorder, you can learn more on our treatment of body dysmorphic disorder treatment page.


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What are opioids?

Opioids are a class of drugs that are commonly prescribed for their analgesic, or pain-killing, properties. They include substances such as morphine, codeine, oxycodone, and methadone. Opioids may be more easily recognized by drug names such as Kadian, Avinza, OxyContin, Percodan, Darvon, Demerol, Vicodin, Percocet, and Lomotil.
Opioids may be classified as natural, semi-synthetic, fully synthetic, or endogenous. Natural opioids such as codeine and morphine are derived from opiate alkaloids contained in the resin of the opium poppy. Semi-synthetic opioids such as oxycodone and hydrocodone are created by chemically altering the natural opioids. Fully synthetic opioids such as methadone are synthesized from non-opioid substances in laboratories. Endogenous opioids are naturally produced by the body and include substances such as endorphins.



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What is Hemophilia? What is Haemophilia?

Hemophilia is a group of inherited blood disorders in which the blood does not clot properly.
Hemophilia is the standard international spelling, also known as haemophilia in the UK, other translations include: hémophilie, hemofilie, hemofili, hemofilia, hämophilie, emofilia. We will use the standard international spelling for the purpose of this section.
Bleeding disorders are due to defects in the blood vessels, the coagulation mechanism, or the blood platelets. An affected individual may bleed spontaneously or for longer than a healthy person after injury or surgery.
The blood coagulation mechanism is a process which transforms the blood from a liquid into a solid, and involves several different clotting factors. The mechanism generates fibrin when it is activated, which together with the platelet plug, stops the bleeding.
When coagulation factors are missing or deficient the blood does not clot properly and bleeding continues.
Patients with Hemophilia A or B have a genetic defect which results in a deficiency in one of the blood clotting factors.
Queen Victoria was a carrier and passed the mutation to her son Leopold, and through several of her daughters to members of the royal families of Spain, Russia, and Germany.
Tsarevich Alexei Nikolaevich, son of Nicholas II (Russia) suffered from hemophilia and was a descendant of Queen Victoria - Rasputin was successful in treating his hemophilia, it was claimed.


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