Archive for November, 2009

How stress affects your immune system

Immune_system_1I have found this study from 2004. I find it worth reading to understand how stress affects our immune system.

We have known for some time that stress affects our immune systems. Many studies have shown that stress can suppress the immune system, but other studies have shown boosts in the immune system under stress. A July 2004 meta-analysis of 293 studies conducted over the past 30 years puts the pieces of the puzzle together.

Psychologists Suzanne Segerstrom, Ph.D., and Gregory Miller, Ph.D. found the following:
-  Stress does indeed affect the immune system in powerful ways.
-  Short-term stressors boost the immune system. It seems that the “fight or flight” response prompts the immune system to ready itself for infections resulting from bites, punctures, scrapes or other challenges to the integrity of the body.
- Chronic, long-term stress suppresses the immune system. The longer the stress, the more the immune system shifted from they adaptive changes seen in the “fight or flight” response to more negative changes, first at the cellular level and later in broader immune function. The most chronic stressors – stress that seems beyond a person’s control or seems endless – resulted in the most global suppression of immunity. Almost all measures of immune system function dropped across the board.
- The immune systems of the elderly or those already sick are more subject to stress-related changes.

In reaching these conclusions the authors looked at the effects of the various stressors on different immune responses, such as “natural” and “specific” immunity. They summarized the results of the studies that looked at each of these types of stress:
- Natural immunity produces quick-acting, all-purpose cells that can attack many pathogens; they bring fever and inflammation.
- The body takes a few days to mount a more specific attack on particular invaders with specific immunity. This response includes lymphocytes (T-cells and B cells). Specific immunity has both cellular responses, which fight pathogens that get inside cells (such as viruses), and humoral responses, which fight pathogens that stay outside cells, such as bacteria and parasites. Segerstrom and Miller were able to assess how different types of immune response correlated with different types of stress because researchers have identified the blood markers of these different immune responses.

They divided stressors into different types:
- Acute time-limited stressors: lab challenges such as public speaking or mental math.
- Brief naturalistic stressors: real-world challenges such as academic tests.
- Stressful event sequences: a focal event such as loss of a spouse or major natural disaster gives rise to a series of related challenges that people know at some point will end.
- Chronic stressors: pervasive demands that force people to restructure their identity or social roles, without any clear end point – such as injury resulting in permanent disability, caring for a spouse with severe dementia, or being a refugee forced from one’s native country by war.
- Distant stressors: traumatic experiences that occurred in the distant past yet can continue modifying the immune system because of their long-lasting emotional and cognitive consequences, such as child abuse, combat trauma or having been a prisoner of war. Much of their analysis goes on to review the similarities and differences among the 293 studies that they examined. These studies included a total of 18,941 subjects. “Stressful event sequences” appeared to be weakly associated with different immune consequences, depending on the type of event. There appeared to be different patterns for grief than for trauma, for example, but the associations weren’t strong enough for the authors to make new claims. They recommended further study.

The authors did find that the most chronic stressors – those which change people’s identities or social roles, are more beyond their control and seem endless – were associated with the most global suppression of immunity. In such situations almost all measures of immune function dropped across the board. The longer the stress, the more the immune system shifted from potentially adaptive changes (such as those in the acute “fight or flight” response) to potentially detrimental changes, at first in cellular immunity and then in broader immune function. This analysis suggests that stressors that turn a person’s world upside down and appear to offer no hope for the future probably have the greatest psychological and physiological impact.

The authors also found that age and disease status affected a person’s vulnerability to stress-related decreases in immune function. It seems that illness and age make it harder for the body to regulate itself.

This is a ground-breaking meta-analysis that helps us understand the complex relationship between stress and the immune system. It should lead to new treatments and to better stress management programs, especially for patients with HIV or other disorders that compromise immunity.

Written by Health Link - I maintain this blog because i like to keep a trace of various Health news through time. I have a wide ranging interest of subject from Massage to Reflexology and other alternative medecines. But the bulk of my interest are scientific discoveries. Visit my website -> Reflexology London
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Ultrasound to be used to destroy cancer tumours

Ultrasound_cancer_1I was very impressed with the news today that a person with rectal cancer in the UK had his tumour destroyed using Ultrasound.
In fact so impressed that i searched some past news and found this article from 2004.
You’ll be impressed. That piece of news was published in 16th Feb 2004 !

The treatment
An invisible knife that uses high-intensity sound waves to penetrate the body and destroy tumours is set to revolutionise cancer treatment, it is claimed.
In five to 10 years ultrasound could replace conventional surgery and radiotherapy for patients with many different types of cancer, scientists said.

About the technique
The technique is undergoing early trials for liver and kidney cancer in the UK while a French team using a different system has already achieved disease-free results treating men with prostate cancer.
In China, where the technology has been pioneered, anecdotal evidence from studies of thousands of patients is said to be “astounding”.
Ultrasound surgery focuses bursts of high energy sound waves on the tumour, heating it to a temperature of 60 degrees Celsius. The tumour cells are destroyed while surrounding tissue is left unharmed.
Professor Gail ter Haar, who is leading trials of an experimental system at the Royal Marsden Hospital in Sutton, Surrey, England, said the technique could treat tumours up to the size of a small orange.

Testing ultrasounds
At this stage the trials are confined to testing the safety of the technique, but Prof ter Haar said they had already yielded “really exciting results”.
She told the American Association for the Advancement of Science’s annual meeting in Seattle yesterday: “I think there will be cancers for which it will revolutionise treatment, but we’re a long way from knowing which they will be, and exactly how it should be employed”.

What is treatment?
Patients with liver and kidney cancer are taking part in the Royal Marsden studies.
Treatment consists of two-second long bursts of ultrasound delivered to the surface of the body by a machine mounted on a gantry.
A number of bursts are needed to clear an organ of cancer.

Testing accross the world
At a different centre in Oxford, England, Prof ter Haar has been using a commercial device developed in China to treat a similar group of patients.
She has worked with Chinese physicians who have already treated about 3,000 cancer patients with ultrasound.
Although the Chinese trials were not as scientifically rigorous as those in the UK, the anecdotal evidence was impressive.
“The results in China are really quite astounding,” said Prof ter Haar.
“There are patients who are disease free with tumours for which there are no other treatments, particularly in the pancreas.”
She said that theoretically, ultrasound should be suitable for a wide range of solid tumours.
“If you can image a tumour with diagnostic ultrasound you should be able to treat it,” she told the meeting.

Not all cancers can be targeted with ultrasound
However, since the sound beam could not travel through bone or air, certain cancers would be difficult to treat.
Brain tumours and lung cancers deep behind the rib cage fell into this category.

Thinking about the tough cancer areas
Scientists in the UK and United States were working on the problem of getting ultrasound into the brain.
“Its very appealing for the brain because it’s a trackless form of damage,” said Prof ter Haar.
“You only get damage at the focus so you don’t damage the rest of the brain through which you’ve got to travel. If we could solve that problem it would be very exciting.”

Different applications and challenges of ultrasound
Dr Jean-Yves Chapelon from the French research institute Inserm in Lyon described a different ultrasound system now at an advanced stage of development which he had used to treat 242 men with prostate cancer.
The results were due to be published in the next few months.
Dr Chapelon said the treatment was as effective as conventional surgery or radiotherapy, and safer.
In this case the ultrasound beam was delivered through the rectum. After five years of followup, 80 per cent of low-risk patients were found to be disease-free and effectively cured.
For medium-risk patients the success rate was 60 per cent and for patients with high-risk aggressive cancers, 50 per cent. The men had an average age of 71.
Traditional treatments for older men with prostate cancer carry a high risk of impotence and urinary incontinence, but 40 per cent of the patients recovered their potency and only eight per cent were unable to control their urine flow.

Impressive results

Not one patient had died of cancer although the first was treated as long as 11 years ago.
“We believe that this therapy challenges other therapies,” said Dr Chapelon.
However, he said that at present it was still difficult to convince specialists that ultrasound therapy could be as good as conventional treatment.
Prof ter Haar said there was still much work to do before ultrasound became universally available as a cancer treatment.
She expected the process of patient trials, publication of data, and introduction into hospitals to take between five and 10 years.

Other applications for ultrasound

Another possible application of ultrasound might be on the battlefield, according to Dr Shahram Vaezy, from the University of Washington in Seattle.
His team was working on miniaturising ultrasound equipment that could be used to treat wounded soldiers, or accident victims.
A big advantage of ultrasound was that it had the ability to stop bleeding by sealing broken blood vessels, he said.
Dr Vaezy told the meeting: “The application we are pursuing is treating internal bleeding, to develop a non-invasive method of treating patients at the scene of an accident, for example”.

Written by Health Link - I maintain this blog because i like to keep a trace of various Health news through time. I have a wide ranging interest of subject from Massage to Reflexology and other alternative medecines. But the bulk of my interest are scientific discoveries. Visit my website -> Reflexology London
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Hypoglycaemia and Hyperglycaemia

blood_sugar_lvl1If blood sugar levels fall or rise abnormally in someone with diabetes, they’ll experience a variety of symptoms.

Hypoglycaemia
Hypoglycaemia is when the blood sugar levels fall below normal. Glycaemia measures is the level of sugar in blood.

Hypoglycaemia may occur:
- after an insulin injection
- after taking oral diabetes medication
- if a meal is missed or delayed
- after strenuous exercise
- if alcohol is drunk on an empty stomach

The symptoms of hypoglycaemia vary from person to person. Mild hypoglycaemia may cause:
- weakness
- dizziness
- sweating
- hunger
- shaking
- irritability
- mood swings

A mild hypoglycaemia can usually be treated with some form of sugar. Types of sugar to use during mild crisis :
- dextrose tablets (carry these if you have diabetes)
- three sugar lumps
- two teaspoons of sugar
- chocolate or sweet biscuits
- a sweet drink

When the blood glucose level falls even lower, then the person may behave strangely and become confused (often mistakenly interpreted as drunkenness). Under these circumstances it may be easier and quicker to give sugar in liquid form, such as a sweet drink.

In severe hypoglycaemia, the person loses consciousness. Under these circumstances an injection of glucagon is given, which temporarily raises the level of blood glucose. Once the person is conscious they can be given some sugar and a snack to prevent the hypo from recurring.

Always have sugar tablets or another form of sugar available

People with diabetes and those close to them are taught to look out for signs that their sugar level may be low, and are advised to always have sugar tablets or another form of sugar available to raise the level quickly. This solves the problem quickly and prevents serious consequences.

People with diabetes are advised to carry some form of identification saying that they have diabetes, so that people will realise their condition should they get into difficulty and need help.

Hyperglycaemia
Hyperglycaemia is when the blood glucose level is too high. When it’s mildly raised then symptoms of uncontrolled diabetes occur, namely excessive thirst, passing urine frequently, tiredness, weakness and lethargy.
If the blood glucose level becomes dangerously high then the person becomes dehydrated and may become comatose. This is a medical emergency that requires hospital treatment.

Written by Health Link - I maintain this blog because i like to keep a trace of various Health news through time. I have a wide ranging interest of subject from Massage to Reflexology and other alternative medecines. But the bulk of my interest are scientific discoveries. Visit my website -> Reflexology London
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Kids asking WHY? have a quite thorough research agenda

kids_whyA child’s never-ending “why’s” aren’t meant to exasperate parents, scientists say. Rather, the kiddy queries are genuine attempts at getting at the truth, and tots respond better to some answers than others.
This new finding, based on a two-part study involving children ages 2 to 5, also suggests they are much more active about their knowledge-gathering than previously thought.

Kids are good at fact finding
“Even from really early on when they start asking these how and why questions, they are asking them in order to get explanations,” lead researcher Brandy Frazier of the University of Michigan told LiveScience.
When explanations came their way, the little ones probed further, they found. “Kids are playing more of an active role in learning about the world around them than we may have expected,” Frazier said.
The new findings, which are detailed in the November/December issue of the journal Child Development, can’t be generalized to all children since the sample sizes were small.

Curious chatter
Past research from the early to mid 1900s on child development had suggested that young children were only aware of temporal relationships between two events and couldn’t differentiate cause from effect until about 7 or 8 years of age. More recent work has suggested otherwise, that as early as age 3 children get causality.
Lacking from such studies are kids’ reactions to the information they get to their causal questions.
To figure out kids’ responses to different questions, Frazier and her colleagues examined transcripts from everyday conversations of six kids, ages 2 to 4, who were speaking with parents, siblings and visitors at home. With just six kids, the researchers analyzed the transcripts, more than 580 of them, as their unit of analysis. Overall, there were more than 3,100 causal how and why questions such as, “Why my tummy so big, mom?” “Why not keep a light on?” and “How can snakes hear if they don’t have ears?”

Fact seeking
Results showed kids were more than twice as likely to re-ask their question after a non-explanation compared with a real answer. And when they did get an explanation, which was about 37 percent of the time, they were more than four times as likely to reply with a follow-up inquiry as if they had received a non-explanatory response.
Preliminary results from a separate new study of Frazier’s suggest there is such a thing as too much information in a response. “It seems like kids might have an optimal level of detail they’re interested in,” Frazier said.

Odd items
The next part of the new study was lab-based and involved 42 preschoolers, ages 3 to 5, who chatted when prompted with toys, storybooks and videos. The items were designed to create surprising, question-provoking situations. For instance, kids were shown a box of all-red crayons, a puzzle with a piece that didn’t fit, and a storybook describing a child who poured orange juice on his cereal.
The adults who showed kids each item had certain explanatory and non-explanatory responses. So as expected, kids asked about the orange-juice scenario: “Why did he do that?” The adult would then respond with the explanation, “He thought it was milk in the pitcher,” or the non-explanation, “I like to put milk on my cereal.”
They found significant differences in types of reactions to the explanatory answers versus the non-explanatory ones. Nearly 30 percent of the time kids would agree, nod or say “oh” after getting a true explanation, compared with just under 13 percent of the time for non-explanations.
For such non-answers, more than 20 percent of the time kids re-asked the original question. Just 1 percent of kids receiving an explanation did the same.
The newly published study was funded, in part, by the National Science Foundation and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Conclusion
If you want your kids to learn you have to make a genuine effort to explain them how the world is.

Written by Health Link - I maintain this blog because i like to keep a trace of various Health news through time. I have a wide ranging interest of subject from Massage to Reflexology and other alternative medecines. But the bulk of my interest are scientific discoveries. Visit my website -> Reflexology London
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