Gene therapy seems to have cured eight of 10 children who had potentially fatal “bubble boy disease,” according to a study that followed their progress for about four years after treatment.
The eight patients were no longer on medication for the rare disease, which cripples the body’s defenses against infection. The successful treatment is reported in Thursday’s issue of the New England Journal of Medicine and offers hope for treating other diseases with a gene therapy approach.
Bubble boy disease is formally called severe combined immunodeficiency, or SCID. This genetic disorder is diagnosed in about 40 to 100 babies each year in the United States. The nickname comes from the experience of a Houston boy, David Vetter, who became famous for living behind plastic barriers to protect him from germs. He died in 1984 at age 12.
He had the most common form of SCID. Recent studies found that gene therapy produced impressive results for that form of the disease, but also carried a risk of leukemia.
The new study involved a different, less common form of SCID _ and one that holds a key position in medical history. In 1990 it became the first illness to be treated by gene therapy, according to the US government. Two Ohio girls improved but continued to take medication.
This form of SCID arises in babies with a genetic defect that leaves them deficient of an enzyme called adenosine deaminase. Patients can be treated with twice-weekly shots of the enzyme or a bone marrow transplant, but the medicine is expensive and marrow transplants don’t always work.
Gene therapy for the new study was performed in Italy and Israel. Researchers removed marrow cells from the patients, equipped the cells with working copies of the gene for the enzyme, and injected the cells back into the patients. In most cases, that was done before age 2.
The journal article reports the outcome two to eight years later, with an average of four years. All 10 patients were still alive, but two needed further treatment. None showed signs of leukemia or other health problems from the therapy, the researchers said.
Dr Donald Kohn, a SCID expert at Childrens Hospital Los Angeles and the University of Southern California, said scientists are trying to understand why gene therapy produces a leukemia risk with the most common form of SCID but not the enzyme-related form.
The new findings are good news for the idea of using gene therapy to treat some other blood cell disorders, including sickle cell disease, said Kohn, who didn’t participate in the new study.
Definition:
A Snellen test uses a chart with different sizes of letters or forms to evaluate your visual acuity-that is, the sharpness of your vision. The test shows how accurately you can see from a distance.
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Description
The traditional Snellen chart is printed with eleven lines of block letters. The first line consists of one very large letter, which may be one of several letters, for example E, H, N, or A. Subsequent rows have increasing numbers of letters that decrease in size. A patient taking the test covers one eye, and reads aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the patient’s visual acuity in that eye.
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The symbols on an acuity chart are formally known as “optotypes.” In the case of the traditional Snellen chart, the optotypes have the appearance of block letters, and are intended to be seen and read as letters. They are not, however, letters from any ordinary typographer’s font. They have a particular, simple geometry in which:
the thickness of the lines equals the thickness of the white spaces between lines and the thickness of the gap in the letter “C”
the height and width of the optotype (letter) is five times the thickness of the line.
Only the ten letters C, D, E, F, L, N, O, P, T, Z are used in the traditional Snellen chart. The perception of five out of six letters (or similar ratio) is judged to be the Snellen fraction.
Wall-mounted Snellen charts are inexpensive and are sometimes used for rough assessment of vision, e.g. in a primary-care physician’s office. Whenever acuity must be assessed carefully (as in an eye doctor’s examination), or where there is a possibility that the examinee might attempt to deceive the examiner (as in a motor vehicle license office), equipment is used that can present the letters in a variety of randomized patterns.
According to BS 4274:1968 (British Standards Institution) “Specification for test charts for determining distance visual acuity” the minimum illumination for externally illuminated charts should be 480 lx, however this very important parameter is frequently ignored by physicians, making many test results invalid.
Snellen fraction
Visual acuity = Distance at which test is made / distance at which the smallest optotype identified subtends an angle of 5 arcminutes.[citation needed]
“20/20” (or “6/6”) vision
Snellen defined “standard vision” as the ability to recognize one of his optotypes when it subtended 5 minutes of arc. Thus the optotype can only be recognized if the person viewing it can discriminate a spatial pattern separated by a visual angle of 1 minute of arc.
In the most familiar acuity test, a Snellen chart is placed at a standard distance, twenty feet in the US. At this distance, the symbols on the line representing “normal” acuity subtend an angle of five minutes of arc, and the thickness of the lines and of the spaces between the lines subtends one minute of arc. This line, designated 20/20, is the smallest line that a person with normal acuity can read at a distance of twenty feet.
Three lines above, the letters have twice the dimensions of those on the 20/20 line. The chart is at a distance of twenty feet, but a person with normal acuity could be expected to read these letters at a distance of forty feet. This line is designated by the ratio 20/40. If this is the smallest line a person can read, the person’s acuity is “20/40,” meaning, in a very rough kind of way, that this person needs to approach to a distance of twenty feet to read letters that a person with normal acuity could read at forty feet. In an even rougher way, this person could be said to have “half” the normal acuity.
Outside of the US, the standard chart distance is six meters, normal acuity is designated 6/6, and other acuities are expressed as ratios with a numerator of 6.
Acuity charts are used during many kinds of vision examinations, such as “refracting” the eye to determine the best eyeglass prescription. During such examinations, acuity ratios are never mentioned.
The biggest letter on an eye chart often represents an acuity of 20/200, the value that is considered “legally blind.” Many people with refractive errors have the misconception that they have “bad vision” because they “can’t even read the E at the top of the chart without my glasses.” But in most situations where acuity ratios are mentioned, they refer to best corrected acuity. Many people with moderate myopia “cannot read the E” without glasses, but have no problem reading the 20/20 line or 20/15 line with glasses. A legally blind person is one who cannot read the E even with the best possible glasses.
Criticism
Snellen charts have been the target of some criticism. The fact that the number of letters increases while the size decreases introduces two variables, rather than just one. Some people may simply (or unconsciously) memorize the Snellen chart before being tested by it, or between tests of one eye and the other, to give the impression that their vision is good. Several studies indicate that the crowding together of letters makes them inherently more difficult to read. Another issue is that there are fairly large and uneven jumps in acuity level between the rows. To address these concerns, more modern charts have been designed that have the same number of letters on each row and use a geometric progression to determine the size of each row of letters. Also, some letters are harder to distinguish than others, such as P vs F, C vs G, Q vs O, etc.
How to prepare for the test?
No preparation is necessary.
How the Test is performed?
You stand or sit at a specific distance from the eye chart. Usually you are told to cover one eye with a cardboard piece or with your hand while you read letters with the other eye and say them out loud for the doctor.
In an eye clinic, you may have a more sophisticated version of this test in which you look at the chart through different strengths of lenses (a little bit like looking through a telescope) so that your doctor can find the proper strength of glasses or contact lenses for you. Sometimes the Snellen chart you see in an eye clinic is actually a reflection on a mirror from a projector in the back of the room. This enables eye doctors to use a variety of charts without you having to move from your chair. The test takes only a few minutes.
Risk Factor:
There are no risks.
How long is it before the result of the test is known?
You can find out immediately whether your vision is normal (“20/20”) or whether you have a vision problem. Glasses do not correct every vision problem, but an eye doctor can tell you if they will help.
Resources:
http://en.wikipedia.org/wiki/Snellen_chart
https://www.health.harvard.edu/diagnostic-tests/snellen-test-for-visual-acuity.htm
A groundbreaking treatment for pain, eight times stronger than morphine, has been discovered by scientists. The revolutionary technique involves an injection of the proteinprostatic acid phosphatase (PAP), which can combat serious discomfort for more than three days — an astonishing 14 times as long as the five hours of pain relief brought about with a dose of morphine.
The substance appears to have few side effects, and works by neutralizing the chemical in your body that causes your brain to feel pain.
A research team pinpointed the identity of a particular “pain protein” in nerve cells, and then found a way of converting it from a substance that causes pain into one that suppresses it.
When nerve cells are in distress, they release a chemical known as adenosine triphosphate (ATP) which creates the sensation of pain. PAP converts the ATP into adenosine — which actually suppresses pain.
Etymology:
The etymology of gangrene derives from the Latin word “gangraena” and from the Greek gangraina , which means “putrefaction of tissues”.
Definition:
Gangrene refers to the decay and death of tissue resulting from an interruption in blood flow to a certain area of your body. Some types of gangrene also involve a bacterial infection. Gangrene most commonly affects the extremities, including your toes, fingers and limbs, but can also occur in your muscles and internal organs.
Your chances of developing gangrene are higher if you have an underlying condition that can damage your blood vessels and impede blood flow, such as diabetes or atherosclerosis.
Gangrene is a complication of necrosis (i.e., cell death) characterized by the decay of body tissues, which become black and malodorous. It is caused by infection or ischemia, such as from thrombosis (blocked blood vessel). It is usually the result of critically insufficient blood supply (e.g., peripheral vascular disease) and is often associated with diabetes and long-term smoking. This condition is most common in the lower extremities.
Treatments for gangrene include surgery to remove dead tissue, antibiotics and other approaches. The prognosis for recovery is good if gangrene is identified early and treated quickly.
The best treatment for gangrene is revascularization (i.e., restoration of blood flow) of the affected organ, which can reverse some of the effects of necrosis and allow healing. Other treatments include debridement and surgical amputation. The method of treatment is generally determined depending on location of affected tissue and extent of tissue loss. Gangrene may appear as one effect of foot binding.
Symptoms:
When gangrene affects your skin, signs and symptoms may include:
*A blue or black discoloration of your skin
*Severe pain followed by a feeling of numbness
*A foul-smelling discharge
If you have a type of gangrene that affects tissues beneath the surface of your skin, such as gas gangrene or internal gangrene, you may notice that:
*The affected tissue is swollen and painful
*You’re running a fever and feel unwell
A condition called septic shock can occur if a bacterial infection that originated in the gangrenous tissue spreads throughout your body. Signs and symptoms of septic shock include:
Causes:
Gangrene occurs when a body part — your skin, muscle or even an organ — loses its blood supply. The blood that feeds your tissues provides oxygen, nutrients to feed your cells and immune system components, such as antibodies, to ward off infections. Without a proper blood supply, your cells can’t survive.
….....CLICK TO SEE Gangrene results when blood flow to a certain area of your body is interrupted, causing tissue decay and death. Gangrene often affects the fingers or toes.
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Any process that affects blood flow — an injury or an underlying condition or especially, a combination of the two — can lead to gangrene.
The types of gangrene include:
Dry gangrene. Dry gangrene is characterized by dry and shriveled skin ranging in color from brown to purplish-blue to black. Usually, dry gangrene develops slowly. It occurs most commonly in people who have a blood vessel disease, such as atherosclerosis.
Wet gangrene. Gangrene is referred to as “wet” if there’s a bacterial infection in the affected tissue. Swelling, blistering and a wet appearance are common features of wet gangrene. It can develop following a severe burn, frostbite or injury. It often occurs in people with diabetes who unknowingly injure a toe or foot. Wet gangrene needs to be treated immediately because it spreads quickly and can be fatal.
Gas gangrene. Gas gangrene typically affects deep muscle tissue. If you have gas gangrene, the surface of your skin may initially appear normal. As the condition progresses, your skin may become pale and then evolve to a grey or purplish-red color. A bubbly appearance to your skin may become apparent, and the affected skin may make a crackling sound when you press on it because of the gas within the tissue.
Gas gangrene is usually caused by an infection by the bacteria Clostridium perfringens, which develops in an injury or surgical wound that’s depleted of blood supply. The bacterial infection produces toxins that release gas — hence the name “gas” gangrene — and cause tissue death. Like wet gangrene, gas gangrene can become life-threatening.
Internal gangrene. Gangrene affecting one or more of your organs, most commonly your intestines, gallbladder or appendix, is called internal gangrene. This type of gangrene occurs when blood flow to an internal organ is blocked. This can occur when your intestines bulge through a weakened area of muscle in your abdomen (hernia) and become twisted. Internal gangrene often causes a fever and severe pain. Left untreated, internal gangrene can be fatal.
CLICK TO SEE Fournier’s gangrene. Fournier’s gangrene is an uncommon type of gangrene that involves the genital organs. Men are most often affected, but women can develop this type of gangrene as well. Fournier’s gangrene usually arises due to an infection in the genital area or urinary tract and causes genital pain, tenderness, redness and swelling.
Risk factors: Several factors increase your risk of developing gangrene. These include:
Age. Gangrene occurs far more often in older people.
Diabetes. If you have diabetes, your body doesn’t produce sufficient amounts of the hormone insulin (which helps your cells take up glucose) or is resistant to the effects of insulin. Diabetes along with its high blood sugar levels can eventually damage blood vessels, interrupting blood flow to a part of your body.
Blood vessel disease. Hardened and narrowed arteries (atherosclerosis) and blood clots also can block blood flow to an area of your body.
Severe injury or surgery. Any process that causes trauma to your skin and underlying tissue, including an injury or frostbite, increases your risk of developing gangrene, especially if you have an underlying condition that impedes blood flow to the injured area.
Immunosuppression. If you have an infection with the human immunodeficiency virus (HIV) or if you’re undergoing chemotherapy or radiation therapy, your body’s ability to fight off an infection is impaired.
Tests and diagnosis:
Your doctor will likely ask you whether you’ve recently experienced any trauma, such as an injury or surgery, to the affected area of your body. You’ll also talk about your medical history, including any chronic conditions, such as diabetes, which could lead to damaged blood vessels.
Tests used to help make a diagnosis of gangrene include:
Blood tests. An abnormally elevated white blood cell count often indicates the presence of an infection.
Imaging tests. An X-ray, a computerized tomography (CT) scan or a magnetic resonance imaging (MRI) scan can be used to view interior body structures and assess the extent to which gangrene has spread.
An arteriogram is an imaging test used to visualize your arteries. During this test, dye is injected into your bloodstream and X-ray pictures are taken to determine how well blood is flowing through your arteries. An arteriogram can help your doctor find out whether any of your arteries are blocked.
Surgery. Surgery may be performed to determine the extent to which gangrene has spread within your body.
Fluid or tissue culture. A culture of the fluid from a blister on your skin may be examined for the bacteria Clostridium perfringens, a common cause of gas gangrene, or your doctor may look at a tissue sample under a microscope for signs of cell death.
Complications:
Gangrene can lead to scarring or the need for reconstructive surgery. Sometimes, the amount of tissue death is so extensive that a body part, such as your foot, may need to be removed.
Gangrene that is infected with bacteria can spread quickly to other organs and may be fatal if left untreated.
Treatment
Treatment is usually surgical debridement, and excision with amputation is necessary in many cases. Antibiotics alone are not effective because they do not penetrate ischemic muscles sufficiently.
History: As early as 1028, when antibiotics had not yet been discovered, fly maggots were commonly used to treat chronic wounds or ulcers to prevent or arrest necrotic spread, as some species of maggots consume only dead flesh, leaving nearby living tissue unaffected. This practice largely died out after the introduction of antibiotics and enzyme to the range of treatments for wounds. Recently, however, maggot therapy has regained some credibility and is sometimes employed with great efficacy in cases of chronic tissue necrosis.
Tissue that has been damaged by gangrene can’t be saved, but steps can be taken to prevent gangrene from progressing. These treatments include:
Surgery. Your doctor will remove the dead tissue, which helps stop gangrene from spreading and allows healthy tissue to heal. If possible, your doctor may repair damaged or diseased blood vessels in order to increase blood flow to the affected area.
A skin graftis a type of reconstructive surgery that may be used to treat gangrene that’s caused extensive damage to your skin. During a skin graft, your doctor removes healthy skin from another part of your body — usually a place hidden by clothing — and carefully spreads it over an affected area. The healthy skin may be held in place by a dressing or by a couple of small stitches. A skin graft can only be done if an adequate blood supply has been restored to the damaged skin.
In severe cases of gangrene, an affected body part, such as a toe, finger or limb, may need to be surgically removed (amputated). In some cases, you may be fitted with an artificial limb (prosthesis).
Antibiotics. Antibiotics given through a vein (intravenous) may be used to treat gangrene that’s become infected. Hyperbaric oxygen therapy. In this type of therapy, you’ll be situated in a special chamber, which usually consists of a padded table that slides into a clear plastic tube. The chamber is pressurized with pure oxygen, and the pressure inside the chamber will slowly rise to about two and a half times normal atmospheric pressure.
Hyperbaric oxygen therapy may be used to treat gas gangrene. Under increased pressure and increased oxygen content, your blood is able to carry greater amounts of oxygen. Blood rich in oxygen inhibits the growth of bacteria that thrive in the absence of oxygen and helps infected wounds heal more easily.
Hyperbaric oxygen therapy may last anywhere from 30 minutes to two hours, and you may require more than one session. During the therapy, your ears might pop as they adjust to the increased pressure. Afterward, you may feel lightheaded and tired.
Other treatments for gangrene may include supportive care, including fluids, nutrients, and pain medication to relieve your discomfort.
Prognosis
Generally, people who have dry gangrene have the best prognoses because dry gangrene doesn’t involve a bacterial infection and spreads more slowly than the other types of gangrene. However, when infected gangrene is recognized and treated quickly, the probability of recovery is good.
Older people, those who are immunocompromised, those who have underlying conditions, such as diabetes, atherosclerosis or some cancers, and those who have advanced cases of gangrene by the time that they seek treatment are most likely to suffer complications from gangrene.
Prevention: Here are a few suggestions to help you reduce your risk of developing gangrene:
*Care for your diabetes. If you have diabetes, make sure you examine your hands and feet daily for cuts, sores and signs of infection, such as redness, swelling or drainage. Ask your doctor to examine your hands and feet at least once a year.
Don’t use tobacco. The chronic use of tobacco products can damage your blood vessels.
Help prevent infections. Wash any open wounds with a mild soap and water and try to keep them clean and dry until they heal.
Watch out when the temperature drops. Frostbitten skin can lead to gangrene, because frostbite impairs blood circulation in an affected area. If you notice that any area of your skin has become pale, hard, cold and numb after prolonged exposure to cold temperatures, call your doctor.
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.
It’s common for a speck of dirt to get blown into your eye, for soap to wash into your eye, or for you to accidentally bump your eye. For these types of minor eye injuries, home treatment is usually all that is needed.
Some sports and recreational activities increase the risk of eye injuries.
*Very high-risk sports include boxing, wrestling, and martial arts.
*High-risk sports include baseball, football, tennis, fencing, and squash.
*Low-risk sports include swimming and gymnastics (no body contact or use of a ball, bat, or racquet).
Blows to the eye:-
Direct blows to the eye can damage the skin and other tissues around the eye, the eyeball, or the bones of the eye socket. Blows to the eye often cause bruising around the eye (black eye) or cuts to the eyelid. If a blow to the eye or a cut to the eyelid occurred during an accident, be sure to check for injuries to the eyeball itself and for other injuries, especially to the head or face. Concern about an eye injury may cause you to miss other injuries that need attention.
Burns to the eye:-
Burns to the eye may be caused by chemicals, fumes, hot air or steam, sunlight, tanning lamps, electric hair curlers or dryers, or welding equipment. Bursts of flames or flash fires from stoves or explosives can also burn the face and eyes.
*Chemical burns can occur if a solid chemical, liquid chemical, or chemical fumes get into the eye. Many substances will not cause damage if they are flushed out of the eye quickly. Acids and alkali substances can damage the eye. It may take 24 hours after the burn to determine the seriousness of an eye burn. Chemical fumes and vapors can also irritate the eyes.
*Bright sunlight (especially when the sun is reflecting off snow or water) can burn your eyes if you do not wear sunglasses that filter out ultraviolet (UV) light. Eyes that are not protected by a mask can be burned by exposure to the high-intensity light of a welder’s equipment (torch or arc). The eyes also may be injured by other bright lights, such as from tanning booths or sunlamps.
Foreign objects in the eye:-
A foreign particle in the eye, such as dirt, an eyelash, a contact lens, or makeup, can cause eye symptoms.
*Objects may scratch the surface of the eye (cornea) or become stuck on the eye. If the cornea is scratched, it can be hard to tell whether the object has been removed, because a scratched cornea may feel painful and as though something is still in the eye. Most corneal scratches are minor and heal on their own in 1 or 2 days.
*Small or sharp objects traveling at high speeds can cause serious injury to many parts of the eyeball. Objects flying from a lawn mower, grinding wheel, or any tool may strike the eye and possibly puncture the eyeball. Injury may cause bleeding between the iris and cornea (hyphema), a change in the size or shape of the pupil, or damage to the structures inside the eyeball. These objects may be deep in the eye and may require medical treatment.
In the case of a car air bag inflating, all three types of eye injuries can occur. The force of impact can cause a blow to the eye, foreign objects may enter the eye, and chemicals in the air bag can burn the eye.
Eye injuries can be prevented by using protective eyewear. Wear safety glasses, goggles, or face shields when working with power tools or chemicals or doing any activity that might cause an object or substance to get into your eyes. Some professions, such as health care and construction, may require workers to use protective eyewear to reduce the risk of foreign objects or substances or body fluids getting in the eyes.
After an eye injury, you need to watch for vision changes and symptoms of an infection. Most minor eye injuries can be treated at home. You may click to See :->the Home Treatment.
EMERGENCIES:-
Call emergency services immediately! Do you have any of the following symptoms that require emergency treatment? Call 911 or other emergency services immediately.
*An object has punctured and penetrated the eye. Note: Do not bandage or put any pressure on the eye. If an object has penetrated the eyeball, hold the object in place to prevent further movement and injury to the eye.
*An eyeball is bulging out of its socket or looks abnormal after an injury.
*Sudden partial or complete vision loss has occurred in one or both eyes. Note: Treatment is needed within 90 minutes to save vision.
*Wear safety glasses, goggles, or face shields when you hammer nails or metal, work with power tools or chemicals, or do any activity that might cause a burn to your eyes. If you work with hazardous chemicals that could splash into your eyes, know how to flush chemicals out, and know the location of the nearest shower or sink.
*If you are welding or near someone else who is welding, wear a mask or goggles designed for welding.
*Wear protective eyewear during sports such as hockey, racquetball, or paintball that involve the risk of a blow to the eye. Baseball is the most common sport to cause eye injuries. Fishhook injuries are another common cause of eye injuries.
Protective eyewear can prevent sports-related eye injuries more than 90% of the time. An eye examination may be helpful in determining what type of protective eyewear is needed.
*Injuries from ultraviolet (UV) light can be prevented by wearing sunglasses that block ultraviolet (UV) rays and by wearing broad-brimmed hats. Be aware that the eye can be injured from sun glare while boating, sunbathing, or skiing. Use eye protection while you are under tanning lamps or using tanning booths. Laser pointers have not been shown to cause eye injury.
*Wear your seat belt when in a motor vehicle. Use child car seats.
Prevention tips for children:-
Eye injuries are common in children, and many can be prevented. Most eye injuries happen in older children. They happen more often in boys than in girls. Toys—from crayons to toy guns—are a major source of injury, so check all toys for sharp or pointed parts. Household items, such as elastic cords, can also strike the eye and cause injury.
Teach your children about eye safety. :-
*Be a good role model—always wear proper eye protection.
*Get protective eyewear for your children and help them use it properly.
*Teach children that flying toys should never be pointed at another person.
*Teach children how to carry sharp or pointed objects properly.
*Teach children that any kind of missile, projectile, or BB gun is not a toy.
*Use safety measures near fires and explosives, such as campfires and fireworks.
Any eye injury that appears unusual for a child’s age should be evaluated as possible child abuse.
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