Categories
News on Health & Science

Babies Born During Pollen Season More Likely to Wheeze

[amazon_link asins=’B00QMZEQGQ,B001BXYJZW,B0196YWTIG,B001V24IAY,B00V31B0YU,B001V28JXG,B00NI9FMTO,B00DKEPFV2,B00M4YU6EK’ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’4a363ca4-4c12-11e7-8131-29f6174d2995′]

 

Newborns born during the high pollen and mould seasons, linked with the presence of allergens, are more likely to develop early symptoms  of asthma, suggests a new study.
.CLICK & SEE
University of California, Berkeley (UC-B) researchers found that such children born in the high mould season, coinciding with the last quarter of the year, have three times the odds of developing wheezing, often an early sign of asthma, compared with those born at other times of the year.

The study may help shed light on why such babies appear to have a higher risk of eventually developing asthma than children born in the summer.

A 2008 study of birth and medical records found that babies born in autumn are at greater risk of later developing childhood asthma.

That study suggested an influence from early exposure to respiratory viruses, which is more common during the peak of cold and flu season.

“In our study, we took a different tack to understand the link between month of birth and asthma by considering ambient concentrations of fungal spores and pollen, which follow distinct seasonal patterns,” said Kim Harley, associate director at UC-B Centre for Children’s Environmental Health Research and co-author of the study.

The researchers examined 514 children born in 1999 and 2000 in California’s Salinas Valley, a region with mild, rainy winters and dry summers.

They identified 27 spore and 48 pollen groups in the study, recording the average daily concentrations for the groups that accounted for more than 3% of the total during the first three months of life for each child in the study.

The researchers found that babies born in autumn and winter have triple the odds of developing early wheezing, often a precursor to asthma, by 24 months of age, said an UC-B release.

The results were reported online in Thorax.

Sources:The Times Of India

Zemanta Pixie
Categories
News on Health & Science

Hot Chillies Can Help Mitigate Pain

[amazon_link asins=’B004B83V3A,B000VM2LQ8,B00VFGMYUW,B005G8IDTQ,B017MFS2BE,B06Y1QQH3D,B00AT7XRLS,B004JPW9TC’ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’f98865a6-9918-11e7-94dc-dbdc1aa93ccb’]

[amazon_link asins=’B06XX51N55,B073SNQG2W,B00ZNJDUNC,B074SZX1R6,B015Q924MQ,B01KYPE8DU,B00OKGV4X2,B06Y3DV3MP,B01JMJTJO2′ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’a74ebf52-9918-11e7-aeda-5d86c413898a’]

[amazon_link asins=’B00Q74B9J4,1784721026′ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’596fc0bd-f1a6-11e6-8398-f92fb2521430′]

[amazon_link asins=’B008QDK7SI,B00MYRUYAI’ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’f22fe8e9-f1a6-11e6-88fb-6b62d492449d’]

Capsaicin, the active agent in spicy hot chili peppers, often acts as an irritant, but it may also be used to reduce pain.

………………...CLICK & SEE
Feng Qin, associate professor of physiology and biophysics at the University at Buffalo School of Medicine, and Jing Yao used capsaicin to unravel how pain-receptor systems can adapt to painful stimuli.

For example, adaptation happens when your eyes adjust from a dark movie theatre during a matinee to the bright sunlight outside. Whether pain receptors truly adapt or rescale their responses (versus simply desensitising) has been an open question.

Scientists had previously linked the analgesic or pain-relieving effects of capsaicin to a lipid called PIP2, found in cell membranes. When capsaicin is applied to the skin it induces a strong depletion of PIP2 in the cell membrane.

“The receptor acts like a gate to the neurons,” said Qin. “When stimulated it opens, letting outside calcium enter the cells until the receptor shuts down, a process called desensitisation.”

“The analgesic action of capsaicin is believed to involve this desensitization process. However, how the entry of calcium leads to the loss of sensitivity of the neurons was not clear,” he said, according to a Buffalo release.

Capsaicin creams are commonly sold over the counter as effective treatment for a variety of pain syndromes, from minor muscle or joint aches to those that are very difficult to treat, such as arthritis and neuropathic pain.

Sources:The Times Of India

Reblog this post [with Zemanta]
Categories
News on Health & Science

Ageing Muscle ‘Given New Vigour’

[amazon_link asins=’099904530X,B01EHO6864,B00H8A2SYG,0989792498,9814508802,B00HRBFEVK,0470259280,0199603383,B01K2PKHLE’ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’8d49a840-8882-11e7-8480-efc9573ab251′]

Scientists have found a way to give old, tired muscles a new lease of life.
Stem cells play a key role in repairing muscle……CLICK & SEE

.
They tweaked biochemical signals in mice to boost the ability of the animal’s stem cells to repair damaged tissue, restoring its youthful vigour.

The breakthrough raises hopes of new treatments for age-related degenerative diseases such as Alzheimer’s and Parkinson’s.

The study, by the University of California, Berkeley, is published in the journal Nature.

“We are one step closer to having a point of intervention where we can rejuvenate the body’s own stem cells so we don’t have to suffer from some of the debilitating diseases associated with ageing” says Dr Morgan Carlson , University of California, Berkeley

Adult stem cells play a key role in helping to repair the mature, differentiated cells that make up the body’s working tissues.

The Berkeley team identified two key regulatory pathways that control how well adult stem cells carry out their repair work.

They were then able to modify the way stem cells reacted to those biochemical signals to revive the ability of muscle tissue in old mice to repair itself nearly as well as the muscle in the mice’s much younger counterparts.

Using adult stem cells to rejuvenate tissue would eliminate the ethical controversy surrounding the use of cells taken or derived from embryos.

Researcher Dr Morgan Carlson said: “We are one step closer to having a point of intervention where we can rejuvenate the body’s own stem cells so we don’t have to suffer from some of the debilitating diseases associated with ageing.”

Regeneration capacity

The Berkeley team compared muscle regeneration capacity of two-year-old mice – comparable in age to a human aged 75-85 – to that in two-month old mice, comparable to a human aged 20-25.

As expected, they found the muscle tissue in the young mice easily replaced damaged cells with healthy new cells, while areas of damaged muscle in the older animals was full of scar tissue.

But when they effectively disabled the “ageing pathway” by blocking production of a key protein called TGF-beta, the level of cellular regeneration in the older animals was comparable the much younger mice.

However, the researchers warned that closing down the ageing pathway completely could run a risk of many health problems, for instance the ability to suppress cell division is key to controlling the development of cancer.

Lead researcher Dr Irina Conboy said the key was to find the right balance between the biochemical pathway which promoted healing, and that which promoted ageing.

“We need to find out what the levels of these chemicals are in the young so we can calibrate the system when we’re older.

“If we can do that, we could rejuvenate tissue repair for a very long time.”

Rebecca Wood, of the Alzheimer’s Research Trust, said: “Since Alzheimer’s causes brain cells to gradually die, research into ways to regenerate them could eventually lead to revolutionary new treatments for this devastating disease.

“More research is needed as this study was conducted on muscle tissue rather than the complex nerve cells in the brain and there are many health problems associated with the suppression of cell division.”

Dr Susanne Sorensen, of the Alzheimer’s Society, said the research was interesting as it had recently been shown that stem cells in the brain might be able to help create new tissue after damage has been done.

“This new research gives further hope that our own stem cells can be used to help regenerate cells in the body.”

Sources: BBC NEWS:June 19, ’08.

Zemanta Pixie
Categories
Ailmemts & Remedies

Anatomic Problems of the Colon

The colon, or large intestine, is part of the digestive system, which is a series of organs from the mouth to the anus. When the shape of the colon or the way it connects to other organs is abnormal, digestive problems result. Some of these anatomic problems can occur during embryonic development of the fetus in the womb and are known as congenital abnormalities. Other problems develop with age.

Colon Anatomy and Development…click & see the pictures

The adult colon is about 5 feet long. It connects to the small bowel, which is also known as the small intestine. The major functions of the colon are to absorb water and salts from partially digested food that enters from the small bowel and then send waste out of the body through the anus. What remains after absorption is stool, which passes from the colon into the rectum and out through the anus when a person has a bowel movement.

The colon comprises several segments:

The colon is formed during the first 3 months of embryonic development. As the bowel lengthens, part of it passes into the umbilical cord, which connects the fetus to the mother. As the fetus grows and the abdominal cavity enlarges, the bowel returns to the abdomen and turns, or rotates, counterclockwise to its final position. The small bowel and colon are held in position by tissue known as the mesentery. The ascending colon and descending colon are fixed in place in the abdominal cavity. The cecum, transverse colon, and sigmoid colon are suspended from the back of the abdominal wall by the mesentery.
Anatomic Problems of the Colon:-

Malrotation and Volvulus....click & see

If the bowel does not rotate completely during embryonic development, problems can occur. This condition is called malrotation. Normally, the cecum is located in the lower right part of the abdomen. If the cecum is not positioned correctly, the bands of thin tissue that normally hold it in place may cross over and block part of the small bowel.

Also, if the small bowel and colon have not rotated properly, the mesentery may be only narrowly attached to the back of the abdominal cavity. This narrow attachment can lead to a mobile or floppy bowel that is prone to twisting, a disorder called volvulus. (See the section on volvulus.)

Malrotation is also associated with other gastrointestinal (GI) conditions, including Hirschsprung’s disease and bowel atresia.

Malrotation is usually identified in infants. About 60 percent of these cases are found in the first month of life. Malrotation affects both boys and girls, although boys are more often diagnosed in infancy.
The colon is held in place by the mesentery
In malrotation, the cecum is not positioned correctly. The tissue that normally holds it in place may cross over and block part of the small bowel.

In infants, the main symptom of malrotation is vomiting bile. Bile is a greenish-yellow digestive fluid made by the liver and stored in the gallbladder. Symptoms of malrotation with volvulus in older children include vomiting (but not necessarily vomiting bile), abdominal pain, diarrhea, constipation, bloody stools, rectal bleeding, or failure to thrive

Various imaging studies are used to diagnose malrotation:...click & see

  • x rays to determine whether there is a blockage. In malrotation, abdominal x rays commonly show that air, which normally passes through the entire digestive tract, has become trapped. The trapped air creates an enlarged, air-filled stomach and upper small bowel, with little or no air in the rest of the small bowel or the colon.
  • upper GI series to locate the point of intestinal obstruction. With this test, the patient swallows barium to coat the stomach and small bowel before x rays are taken. Barium makes the organs visible on x ray and indicates the point of the obstruction. This test cannot be done if the patient is vomiting.
  • lower GI series to determine the position of the colon. For this test, a barium enema is given while x rays are taken. The barium makes the colon visible so the position of the cecum can be determined.
  • computed tomography (CT) scan to help determine and locate the intestinal obstruction.

Malrotation in infants is a medical emergency that usually requires immediate surgery. Surgery may involve

Surgery to relieve the blockage of the small bowel is usually successful and allows the digestive system to function normally.

Small Bowel and Colonic Intussusception

Intussusception is a condition in which one section of the bowel tunnels into an adjoining section, like a collapsible telescope. Intussusception can occur in the colon, the small bowel, or between the small bowel and colon. The result is a blocked small bowel or colon.

Intussusception is rare in adults. Causes include

  • benign or malignant growths
  • adhesions (scarlike tissue)
  • surgical scars in the small bowel or colon
  • motility disorders (problems with the movement of food through the digestive tract)
  • long-term diarrhea

Some cases of intussusception have been associated with viral infections and in patients living with AIDS. It can also occur without any known cause (idiopathic).

In infants and children, intussusception involving the small bowel alone, or the small bowel and the colon, is one of the most common causes of intestinal obstruction. Malrotation is a risk factor. Intussusception affects boys more often than girls, with most cases happening at 5 months and at 3 years of age. Most cases in children have no known cause, but viral infections or a growth in the small bowel or colon may trigger the condition. In the past, cases of intussusception appeared to be associated with a childhood vaccine for rotavirus, a common cause of gastroenteritis (intestinal infection). That vaccine is no longer given.

In adults with intussusception, symptoms can last a long time (chronic symptoms) or they can come and go (intermittent symptoms). The symptoms will depend on the location of the intussusception. They may include

  • changes in bowel habits
  • urgency—needing to have a bowel movement immediately
  • rectal bleeding
  • chronic or intermittent crampy abdominal pain
  • pain in a specific area of the abdomen
  • abdominal distention
  • nausea and vomiting

Children with intussusception may experience

  • intermittent abdominal pain
  • bowel movements that are mixed with blood and mucus
  • abdominal distention or a lump in the abdomen
  • vomiting bile
  • diarrhea
  • fever
  • dehydration
  • lethargy
  • shock (low blood pressure, increased heart rate requiring immediate attention)

If intussusception is not diagnosed promptly, especially in children, it can cause serious damage to the portion of the bowel that is unable to get its normal blood supply. A range of diagnostic tests may be required. X rays of the abdomen may suggest a bowel obstruction (blockage). Upper and lower GI series will locate the intussusception and show the telescoping. CT scans can also help with the diagnosis. When intussusception is suspected, an air or barium enema can often help correct the problem by pushing the telescoped section of bowel into its proper position.

Both adults and children may require surgery to straighten or remove the involved section of bowel. The outcome of this surgery depends on the stage of the intussusception at diagnosis and the underlying cause. With early treatment, the outcome is generally excellent. In some cases, usually in children, intussusception may be temporary and reverse on its own. If no underlying cause is found in these cases, no specific treatment is required.

Fistulas….click & see

A fistula is an abnormal passageway between two areas of the digestive tract. An internal fistula occurs between two areas of intestine or an area of intestine and another organ. An external fistula occurs between the intestine and the outside of the body. Both internal and external fistulas may be characterized by abdominal pain and swelling. External fistulas may discharge pus or intestinal contents. Internal fistulas can be associated with diarrhea.

The most common types of fistulas develop around the anus, colon, and small bowel. These types are

  • ileosigmoid  occurs between the sigmoid colon and the end of the small bowel, which is also called the ileum....click & see
  • ileocecal occurs between the ileum and cecum…...click & see
  • anorectal occurs between the anal canal and the skin around the anus....click & see
  • anovaginal occurs between the rectum and vagina...click & see
  • colovesical occurs between the colon and bladder…....click & see
  • cutaneous occurs between the colon or small bowel and the outside of the body….click & see

Fistulas can occur at any age. Some fistulas are congenital, which means they occur during the development of a baby. They are seen in infants and are more common in boys. Other fistulas develop suddenly due to diseases or after trauma, surgery, or local infection. A fistula can form when diseased or damaged tissue comes into contact with other damaged or nondamaged tissue, as seen in Crohn’s disease (intestinal inflammation) and diverticulitis. Childbirth can lead to fistulas between the rectum and vagina in women.

External fistulas are found during a physical examination. Internal fistulas can be seen by colonoscopy, upper and lower GI series, or CT scan.

Fistulas may be treated by surgery to remove the portion of the intestine causing the fistula, along with antibiotics to treat any associated infection.

Colonic Atresia

Colonic atresia is a condition that occurs during embryonic development in which the normal tubular shape of the colon in the fetus is unexpectedly closed. This congenital abnormality may be caused by incomplete development of the colon or the loss of blood flow during its development. Colonic atresia is rare and may occur with the more common small bowel atresia.

Infants with colonic atresia have no bowel movements, increasing abdominal distention, and vomiting. X rays will show a dilated colon above the obstruction, which can then be located using a barium enema.

Surgery is necessary to open or remove the closed area and re-connect the normal sections of the colon.

Volvulus

Volvulus refers to the twisting of a portion of the intestine around itself or a stalk of mesentery tissue to cause an obstruction. Volvulus occurs most frequently in the colon, although the stomach and small bowel can also twist. The part of the digestive system above the volvulus continues to function and may swell as it fills with digested food, fluid, and gas. A condition called strangulation develops if the mesentery of the bowel is twisted so tightly that blood flow is cut off and the tissue dies. This condition is called gangrene. Volvulus is a surgical emergency because gangrene can develop quickly, cause a hole in the wall of the bowel (perforation), and become life-threatening.

In the colon, volvulus most often involves the cecum and sigmoid segment. Sigmoid volvulus is more common than cecal volvulus.

Sigmoid Volvulus
The sigmoid is the last section of the colon. Two anatomic differences can increase the risk of sigmoid volvulus. One is an elongated or movable sigmoid colon that is unattached to the left sidewall of the abdomen. Another is a narrow mesentery that allows twisting at its base. Sigmoid volvulus, however, can occur even without an anatomic abnormality.

Risk factors that can make a person more likely to have sigmoid volvulus are Hirschsprung’s disease, intestinal pseudo-obstructions, and megacolon (an enlarged colon). Adults, children, and infants can all have sigmoid volvulus. It is more common in men than in women, possibly because men have longer sigmoid colons. It is also more common in people over age 60, in African Americans, and in institutionalized individuals who are on medications for psychiatric disorders. In addition, children with malrotation are more likely to get sigmoid volvulus.

The symptoms can be acute (occur suddenly) and severe. They include a bowel obstruction (commonly seen in infants), nausea, vomiting, bloody stools, abdominal pain, constipation, and shock. Other symptoms can develop more slowly but increase over time, such as severe constipation, lack of passing gas, crampy abdominal pain, and abdominal distention. A doctor may also hear increased or decreased bowel sounds.

Several tests are used to diagnose sigmoid volvulus. X rays show a dilated colon above the volvulus. Upper and lower GI series help locate the point of obstruction and show whether malrotation of the rest of the colon is present. A CT scan may be used to show the degree of twisting and malrotation, and whether perforation has occurred.

In most instances, a sigmoidoscope, a tube used to look into the sigmoid colon and rectum, can be used to reach the site, untwist the colon, and release the obstruction. However, if the colon is found to be twisted very tightly or is twisted so tightly that blood flow is cut off and the tissue is dead, immediate surgery will be needed to correct the problem and, if possible, restore the blood supply. Dead tissue will be removed during surgery, and a portion of the colon may be removed as well—a procedure called a resection. Sigmoid volvulus can recur after untwisting with the sigmoidoscope, but resection eliminates the chance of recurrence. Prompt diagnosis of sigmoid volvulus and appropriate treatment generally lead to a good outcome.

Cecal Volvulus

Cecal volvulus is the twisting of the cecum and ascending segment of the colon. Normally, the cecum and ascending colon are fixed to the internal abdominal wall. If not, they can move and become twisted. The main symptoms of cecal volvulus are crampy abdominal pain and swelling that are sometimes associated with nausea and vomiting.

In testing, x rays will show the cecum out of its normal place and inflated with trapped air. The appendix may be filled with gas, but little or no gas is seen in other parts of the colon. Upper and lower GI series will locate the volvulus and the position of the colon. A CT scan may show how tightly the volvulus is twisted. A colonoscopy, which uses a small, flexible tube with a light and a lens on the end to see the inside of the colon, can sometimes be used to untwist the volvulus. If the cecum becomes gangrenous or holes develop in it, surgery will be needed.
……..In volvulus, a portion of the intestine twists around itself.

Imperforate Anus (Anal Atresia)

Imperforate anus or anal atresia is a congenital abnormality in which the anorectal region is abnormal or incompletely developed. In some cases, the rectum may end and not connect with the anus, or it may connect in the wrong spot. For example, it may connect to the urethra, bladder, or vagina. (See the section on fistulas). In other cases, the anus may be very narrow or missing altogether. The result is that stool cannot pass out of the colon. Imperforate anus occurs in about 1 in 5,000 infants.

Another malformation that results in absence of a functioning anus is congenital cloaca. In patients with this abnormality, the anal muscles and vagina fail to form and the result is a large, ill-defined opening that represents the rectum as well as the vagina and bladder, depending on the extent of the defect. Cloaca deformity of the anus usually requires a colostomy but may be correctable with a surgical procedure that transfers a muscle from another part of the body to create a functioning sphincter at the anus.

Symptoms of imperforate anus include

  • no bowel movement within 24 to 48 hours after birth
  • a missing or misplaced anal opening
  • stool that comes out of the vagina or urethra
  • abdominal swelling (distention)

Imperforate anus is usually found when the infant is first examined after birth. Imperforate anus is categorized on the basis of the location of the end of the rectum in relation to the muscles that support the rectum and other organs in the pelvis, called the levator ani muscles. These location categories are

  • high: the rectum ends above the muscles
  • intermediate: the rectum ends at the level of the muscles
  • low: the rectum ends below the muscles

In all cases of imperforate anus, surgery is necessary to reconstruct the anus. Low imperforate anus is corrected through a minor procedure just after birth. High imperforate anus may require surgery to separate the rectum from the other organs if the rectum is connected with them. The outcome is usually very good, but some infants may not develop good bowel control after surgery because the anal muscles may not form. A child with high imperforate anus often has other GI problems, such as malrotation and intestinal atresia

Factors that affect the outcome of treatment include the location of the abnormality, the patient’s sex, and the age at which the surgery is done. Surgery to correct low imperforate anus in boys usually has an excellent outcome. Correcting cloaca in girls requires a more difficult procedure and is more prone to complications.

Hope Through Research

The National Institute of Diabetes and Digestive and Kidney Diseases, through its Division of Digestive Diseases and Nutrition, supports basic and clinical research into GI diseases, including GI structure; the growth of GI cells in normal and disease states; tissue injury, repair, and regeneration; and Crohn’s disease. Research includes new methods that will help physicians and researchers see inside the body, thereby increasing the detection rate for anatomic problems of the colon.

POINTS TO REMEMBER:
1.Anatomic problems of the colon are caused by changes in the shape of the colon or the way it connects to other organs.

2.Anatomic problems may be congenital or develop with age.

3.Anatomic problems can block the passage of food through the digestive system. Some problems can become life-threatening.

4.Symptoms of anatomic problems include abdominal pain, abdominal distension, vomiting, and diarrhea or constipation.

5.Some anatomic problems may resolve over time; others may need to be corrected with surgery.

For More Information

Crohn’s & Colitis Foundation of America (CCFA)
386 Park Avenue South, 17th Floor
New York, NY 10016–8804
Phone: 1–800–932–2423 or 212–685–3440
Fax: 212–779–4098
Email: info@ccfa.org
Internet: www.ccfa.org

International Foundation for Functional Gastrointestinal Disorders (IFFGD)
P.O. Box 170864
Milwaukee, WI 53217–8076
Phone: 1–888–964–2001 or 414–964–1799
Fax: 414–964–7176
Email: iffgd@iffgd.org
Internet: www.iffgd.org

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.

Source:http://digestive.niddk.nih.gov/ddiseases/pubs/anatomiccolon/index.htm#Volvulus

Categories
News on Health & Science

Slowing Down Life’s Clock

[amazon_link asins=’0307462889,0230112056,1612432735,192912533X,1929125313,0746011091,1499729901,1592409326,147673609X’ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’6d82fbd4-f81d-11e7-ba94-395c1f0614e3′]

Decades of research on aging are beginning to pay off, although it doesn’t mean that increasing longevity is a pill away, writes T.V. Jayan

click & see
It’s been a decade and a half since Cynthia Kenyon genetically tweaked roundworms to expand their lifespan to twice the normal length. Science has not been able to uncork the fountain of youth yet, but the jump-start Kenyon and her colleagues at the University of California, San Francisco, gave to longevity research    by making the wrigglers, through the manipulation of a single gene, live for 40 days instead of 20  has helped resolve many mysteries surrounding the issue of ageing.

The latest in the list is the revelation that the ubiquitous molecule, insulin, comes in the way of a prolonged lifespan. Another independent study points to the benefits calorie restriction has on longevity by making nearly starved roundworms live 40 per cent longer than their well-fed peers.

Too much insulin ” a hormone that tells our cells to use sugar from the bloodstream, thus helping us to avoid metabolic complications that lead to diseases such as diabetes  in the brain may not be a good sign, said a team of researchers from the Howard Hughes Medical Institute in Boston.

By saying so, the researchers  led by endocrinologist Morris White  scientifically reinforced what every mother might tell her child: Eat a good diet and exercise; it will keep you healthy.

The researchers, who sought to understand the role of the insulin-signalling pathway in extending lifespan, found actually the opposite of what most scientists and clinicians believed. Because, according to White, most would find it difficult to accept the idea that insulin can reduce lifespan. This signalling pathway of insulin governs growth and metabolic processes in cells throughout the body.

Tests on lab mice showed that when both the copies of a gene responsible for insulin signalling called Irs2  were knocked off in the brain but retained in cells in other organs, the animals lived about six months longer than usual. This is nearly 18 per cent more than the animal  normal lifespan.

This even though the genetically modified mice were overweight and had higher blood insulin levels. To the scientist’s  surprise, they became more active with age and their glucose metabolism resembled that of younger mice. Besides, their brains showed higher levels of superoxide dismutase, an antioxidant enzyme that protects cells from damage caused by highly reactive chemicals called free radicals.

So diet, physical activity and lower weight keep one’s peripheral tissues sensitive to insulin. This reduces the amount and duration of insulin secretion required to keep glucose under control when one eats. This way, the brain is exposed to less insulin. And since insulin turns on Irs2, the lower the insulin, the lower the IRs2 activity, White observed. The findings were reported in the July 20 issue of the journal Science.

While White’s team pointed to a balanced diet and keeping fit as the recipe for a long life, Andrew Dillin of the Salk Institute of Biological Studies in the US   who had co-authored several papers on ageing with Kenyon  found a gene in roundworms that specifically links calorie restriction to longevity. Interestingly, an Indian scientist, Kalluri Subba Rao, arrived at a similar conclusion more than a decade ago by studying undernourished people and comparing them with those who ate a normal diet.

Dillin and his colleagues in a way cracked open the black box of how persistent hunger increases longevity. “After 72 years of not knowing how calorie restriction works, we finally have genetic evidence to unravel the underlying molecular programme required for increased longevity in response to calorie restriction,” he said.

What is significant about his work is that the gene they identified, pha-4, is independent of those involved in the insulin pathway, which has been the focus of most longevity research so far. The loss of only this gene       which encodes for the protein PHA-4  negated the lifespan-enhancing effects of calorie restriction in worms. So the scientists did the opposite  that is, overexpress the pha-4 gene in the worms. It worked, and the worms lived as much as 40 per cent longer.

Human beings, says Dillin, possess three genes similar to the pha-4 gene of worms, all belonging to what is called the Foxa family. These three genes play an important role in the development and later, the regulation, of glucagon — a pancreatic hormone that, unlike insulin, increases the blood sugar concentration and maintains the body’s energy balance, especially during fasting.

Subba Rao, an emeritus professor at the University of Hyderabad who in 1996 reported the benefits of diet restriction on ageing, agrees. Down-regulating glucose signalling has several positive effects, longevity being one of them.  The body is programmed to metabolise, say, one tonne of sugar over a lifetime. In how much time one does it is entirely up to that person,” said Subba Rao, coordinator of the university’s Centre for Research and Education in Ageing.

Concerted efforts over the last 15 years in the biology of ageing are paying off, although it doesn’t mean that increasing one’s lifespan is a pill away. But scientists are already taking the research to the next level: studying the proteins involved in the process. Examining the process of ageing from the protein perspective may lead to therapeutic methods of delaying ageing in the not-so-distant future, provided the scientists repeat in humans the feats they have achieved in worms and mice.

Last week, a team of researchers at the Scripps Research Institute in La Jolla, California, identified some 86 proteins whose abundance varied in mutant round worms as compared to normal ones. While 47 of the proteins were more abundant in worms that were genetically altered to live twice longer, another 39 were less abundant than in the controls. “Proteins are harder to study but they are closer to the enzymatic processes involved,” John Yates, who led the study, told KnowHow.

Enzymatic processes are the closest one can get when it comes to therapeutics as they are part of the bodys routine biochemical processes. It is for the same reason that many new-generation drugs today have enzymes as their key component.

Source: The Telegraph (Kolkata, India)

css.php