Saturday, 29 August 2009
aspergers syndrome
Friday, 28 August 2009
irritable bowel
IBS can cause repeated long-term bouts of pain |
However, it remains something of a mystery to medical science.
What is it?
As the name suggests, IBS is a disorder which affects the lower digestive tract.
The contents of the bowel are moved along by a rhythmic tightening and relaxation of the muscles of the intestinal wall - a process called peristalsis.
It appears that peristalsis is stronger and more frequent in people with IBS.
This can cause a wide range of symptoms, including regular abdominal pain, diarrhoea and constipation.
Who gets it?
The condition is thought to affect up to one in five of the population.
However, it may be even more common because it is thought that many people never seek a medical opinion.
It is particuarly common among people aged 20 to 30, and twice as common in women than men.
What are the symptoms?
The main symptoms of IBS are:
- Repeated abdominal pains and tenderness
- Diarrhoea
- Constipation
- A bloated feeling
- Headache
- Burping
- Bad breath
- Tiredness
- Nausea
- A sense of incomplete emptying after going to the toilet
Nobody knows for sure.
Scientists believe that part of the problem is likely to be a fault in the way that the body uses serotonin, a chemical which coordinates contractions of the muscles.
The bowel can over-react to all sorts of things, including food, exercise and hormones.
There is evidence to suggest the condition may be related to stress in some people. Up to 60% of IBS patients show signs of anxiety or depression.
In some instances, the condition develops after a gastrointestinal infection.
There may also be a link to increased sensitivity or intolerance to certain foods.
How is IBS diagnosed?
Pinning down the condition can be difficult, and sometimes IBS is only considered after other conditions have been ruled out.
Tests which may be carried out include X-rays, and an endoscopy, in which a thin tube housing a camera is inserted into the bowel.
Doctors sometimes work on the rule of thumb that a patient must have suffered significant abdominal pains for at least 12 weeks in the last 12 months, along with two of the following three symptoms:
- Pain which is relieved by defecation
- Pain associated with a change in the frequency of bowel movement
- A change in the form of the stool
A healthy diet with plenty of fresh fruit and vegetables, and lots of water is a good idea.
Avoiding certain foods and drink can also help. These include: spicy and fatty foods, gas producing vegetables, such as beans, alcohol, tea and coffee.
Several drugs can help:
- Antispasmodics can slow contractions in the bowel, which helps with diarrheoa and pain.
- Laxatives can tackle constipation
For some relaxation techniques, and hypnosis may be useful.
bacterial gastroenteritis
Women are more prone to IBS |
University of Southampton researchers asked 620 people with gastroenteritis about stress and their illness.
Those who pushed themselves or were particularly anxious about symptoms were more likely to develop IBS.
Experts said the study, published in Gut, may explain why only some people develop IBS after a gut infection.
These are people who have high expectations of always doing the right thing Dr Rona Moss-Morris |
Up to one in 10 people develop it after a having a bacterial gut infection, having previously been healthy.
Such infections cause inflammation and ulceration in the bowel and can cause severe vomiting and rectal bleeding.
'Not hypochondriacs'
In this study, each person was checked three and six months after their initial bout of bacterial gastroenteritis to see if they had developed IBS symptoms such as diarrhoea, constipation, abdominal pain and bloating.
In all, 49 people had IBS at both points. Women were more than twice as likely to have IBS as the men.
Those with IBS were significantly more likely to have reported high levels of stress and anxiety and psychosomatic symptoms than those who did not develop the condition.
They were also significantly more likely to be "driven", carrying on regardless until they were forced to rest, which the researchers say simply makes the initial condition worse and longer-lasting, potentially leading to IBS.
Dr Rona Moss-Morris, who led the research, said: "We found people's beliefs about their symptoms, how anxious they got and their behaviour were all important.
"These people were not hypochondriacs. But they did have a negative attitude towards their symptoms."
She added: "These are people who have high expectations of always doing the right thing - and going off work goes against their beliefs."
Such people try to remain active and may go back to work too soon, she said.
"They keep going - but then collapse in a heap.
"They are 'all or nothing' people who have high expectations of themselves."
Trigger
Dr Moss-Morris said people who appear to have problems recovering from a bout of gastroenteritis could be investigated to see if they have a particularly anxious or perfectionist personality.
She suggested cognitive behavioural therapy might be an effective treatment.
But she added there was no suggestion that IBS was "all in the mind".
Professor Robin Spiller, an IBS expert from University Hospitals Nottingham and the editor of Gut, said: "There is probably a complicated mechanism at work here."
He said there were two potential explanations.
"It might be that stress and anxiety affects the immune system.
"But it could also be that if you don't rest, it might do you more harm."
Soluble fibre 'effective for IBS
Irritable bowel syndrome is a common condition |
They found psyllium was the most effective, warning that bran may even worsen the symptoms of the condition, the British Medical Journal reported.
As many as one in 10 people is estimated to have the condition.
It is characterised by abdominal pain and an irregular bowel habit.
I think adding psyllium to the diet is the best treatment option to start with Dr Niek de Wit, researcher |
Many relying on dietary adjustments still turn to bran in a bid to help improve the way the intestines work.
But the Dutch study of 275 patients questions the wisdom of this approach.
The team gave patients 10g of either psyllium, bran or rice flour twice a day for 12 weeks.
Symptom severity
At the end of the study, those on psyllium, a naturally occurring vegetable fibre, reported symptom severity had been reduced by 90 points using a standard scale of rating problems.
For bran it was 58 points and for the placebo group, 49.
The report also showed that patients seemed less tolerant of bran, with more than half of the group dropping out during the trial, mostly because their symptoms worsened.
Soluble fibre can also be found in fruit such as apples and strawberries, as well as barley and oats.
But Dr Niek de Wit, one of the researchers, said: "It is unlikely that people with IBS would get enough from fruit and other foods to help them.
"I think adding psyllium to the diet is the best treatment option to start with. In the study, people did this by adding it to things such as yoghurt and it had a real effect."
Dr Anton Emmanuel, medical director of Core, the charity for diseases of the gut, said bran was being over-used.
He said the study was "helpful" and "reasonably robust", adding: "Putting it all together, patients should tolerate this form of fibre well and it may help some, especially those with a tendency to constipation."
nhs profit themselves
Drug export warning to NHS trusts
Drugs are more expensive outside the UK |
NHS hospital trusts in England have been warned against any attempt to cash in by exporting medicines intended for NHS patients.
The Health Service Journal reports some trusts have considered taking advantage of the weak pound to make a profit.
But the government's chief pharmaceutical offer Dr Keith Ridge has written to all NHS trusts, calling the practice irresponsible.
Dr Ridge warned it could threaten the quality of patient care.
It is shocking and disgraceful that some NHS managers are said to be considering plans to export medicine Norman Lamb Liberal Democrat health spokesman |
He said it was particularly irresponsible to export pharmaceuticals at a time when the supply chain was threatened by the swine flu pandemic.
The low value of the pound means drugs could be bought in sterling, then sold on in countries where prices are higher.
This, combined with the Department of Health's pharmaceutical price regulation scheme, which keeps UK medicine prices low, has presented trusts in theory with a chance to make substantial financial gains.
Commenting on the report, a Department of Health spokesperson said: "Exporting medicines for short term financial gain is an unacceptable practice.
"We are confident that the vast majority of hospital pharmacists are behaving responsibly.
"However, Dr Ridge has written to all hospital pharmacists to underline that such practices are contrary to acceptable professional behaviour."
Naming and shaming
Norman Lamb, Liberal Democrat health spokesman, said pharmacists had been warning for some time that medicine shortages were having a negative impact on patient care.
He said: "It is shocking and disgraceful that some NHS managers are said to be considering plans to export medicine, rather than addressing this serious problem.
"With concerns about swine flu already putting the NHS under pressure, we must ensure that we do not run short of vital drugs in the UK.
"There is a strong case for naming and shaming those trusts involved and taking appropriate disciplinary action."
Thursday, 27 August 2009
biofools
BBC News |
It was a case of two worlds gently bumping, rather than colliding, into one another on the steps of the Bank of England.
Smartly-dressed men and women inched their way past people who looked as though they were off to a festival, equipped with rucksacks, mats and sleeping bags.
But there was something more serious on the agenda for those sitting patiently in the sun - they were waiting for the location of Climate Camp 2009 to be revealed.
The Bank of England was one of six spots around London where those intending to join the camp had been told to wait until a text message from the organisers would tell them where to "swoop".
Campers set about pitching tents at the start of the week-long protest |
Among those waiting was 23-year-old Frank, from east London, who said he planned to stay at the camp "for as much as I can" and talked of humanity "committing suicide".
After several hours, and a quick bingo-type game to keep the crowd of about 200 people occupied, an announcement was made to head for the Cutty Sark stop on the Docklands Light Railway.
Part way through the journey, as the train emerged from underground, mobiles began to beep and vibrate and the location was revealed as Hare and Billet Road in Blackheath.
Raise awareness
One camper on the train helpfully mentioned the area was linked with Wat Tyler and his army, who marched on London in protest at the first poll tax in 1381 and stationed the men in Blackheath.
And so it was that a large, flat patch of Blackheath grass, beneath an increasingly ominous-looking sky, was "swooped upon" by the climate campers.
The site is known as Dartmouth Field.
One of the first to arrive was Max, 26, from south London - among a group of cyclists who met underneath Waterloo Bridge.
He confessed to not being terribly well prepared for the trip, and said he hoped to return to actually stay over the weekend.
Kate Salter is looking to learn more about sustainable living |
"The best we can hope for is that it raises enough attention so that people become interested and find out what climate change is and what Climate Camp are doing about it."
Kate Salter, 29, came up from Brighton with her three-year-old daughter Jem.
"I'm quite interested in the workshops they are running, which will teach you about sustainable living and how to help the environment."
The skyline of the financial buildings of the Docklands can be seen in the background.
Around the site campaigners pitched tents, as others arrived with small vans and unloaded creature comforts including a sofa. One pile of items even has two toilet seats on the top.
It was hard to spot any police - a couple of vans drove past slowly, but nothing more.
Despite this, a fence was swiftly erected, which will apparently be guarded around the clock by the campaigners for the week-long duration of the camp.
Tripods made up of metal scaffolding poles also sprung up, each with someone sitting on top.
Some said these were to stop police entering the field in vehicles - a kind of human shield.
Guy's job is to construct some toilets |
And in one section of the field, there was an impressive amount of wood lying on the grass.
Standing among it, with a plan to transform it into toilets, was 22-year-old student Guy.
"I hope the camp will help people realise that we can't have more climate change dialogue now," he said.
"We've got to the point where we have to stop talking about it and must do something about it instead."
From a van, mattresses are unloaded for the "wellbeing space", which according to one woman was where people can find "comfort, relaxation, and tea".
I'm supportive of their cause but I hope there's no permanent damage to the heath and that they take all their rubbish away with them Julian Crispin, Blackheath resident |
In the distance, in a stroke of opportunism, an ice-cream van parked at the kerb, looking to benefit from the 800 to 1,000 people at the site by now.
Standing on the edge of the field, local resident Julian Crispin, 74, who lives five minutes away, was walking his dog, Percy.
"I just wondered whether it suits their purpose to be out here rather than in central London," he said.
"I'm supportive of their cause but I hope there's no permanent damage to the heath and that they take all their rubbish away with them.
"I also hope they don't keep the neighbours up all night, playing their bongo drums and such like."
A short while later, the campers gathered round, and announcements were made over a patchy loudspeaker system.
"Can I have a whoop for the swoop?" cried a young woman, and the crowd responded with gusto.
Climate Camp 2009 has begun with high hopes and dreams of a better world. What it will actually achieve remains to be seen.
bad managers?
Health Secretary Alan Johnson has rejected calls for a public inquiry into "appalling" standards of emergency care at Stafford Hospital.
During a visit to the hospital he said an independent inquiry into its failings had already been conducted by NHS Watchdog the Healthcare Commission.
It said 400 more people died than would be expected and managers put targets ahead of patient care.
Mr Johnson said he was meeting staff and patient groups at the hospital.
He said he was invited by the town's Labour MP David Kidney.
Professor Sir George Alberti, National Clinical Director for Emergency Access, began an independent review of Stafford Hospital and its trust on Wednesday.
Mr Johnson said the hospital now had more than 100 extra nurses |
Families and MPs have called for a full public inquiry to be held into the hospital's failings.
But Mr Johnson said: "We have made it absolutely clear that the independent inquiry was the Healthcare Commission and the Healthcare Commission was set up precisely to be independent, to monitor these issues, to go in and get behind the statistics and they've done their job very well."
He said the hospital's problems were down to "chronic understaffing and poor management" but accepted the Healthcare Commission's view that things had since improved.
He said there were now three more consultants, 14 extra housekeepers, nine additional matrons, more than 100 more nurses and 36 extra doctors in the department.
Former chief executive Martin Yeates is currently suspended on full pay but Mr Johnson again rejected calls for him to be sacked.
He said: "I want due process to go on here i want everyone to be treated fairly including the previous chief executive."
nhs appalling
What are the lessons for the NHS?
By Nick Triggle BBC News health reporter |
Inspectors employ a light touch to NHS regulation |
Back in the summer of 2007 analysts working deep in the bowels of the leading London university Imperial College noticed something appeared amiss at a hospital many miles away.
The researchers, working for the private group Dr Foster, had spotted death rates at Mid Staffordshire NHS Trust were too high.
They raised the issue with the Healthcare Commission in July, and then the following month more anomalies were noted by the Imperial team.
The Healthcare Commission's own assessment system also started noticing potential problems, and within months a full investigation was launched.
It resulted in the watchdog publishing one of its most damning reports on an individual NHS trust.
The Healthcare Commission said standards of emergency care were "appalling" and would have led to unnecessary deaths.
Lessons to be learned
But what are the implications for the rest of the NHS?
Healthcare Commission chairman Sir Ian Kennedy said it was a story of one badly run hospital.
Everyone else was fobbed off. We alone stayed the course Sir Ian Kennedy Healthcare Commission |
None of these have thrown up the combination of concerns raised in the Mid Staffordshire report - namely low staffing levels, inadequate nursing, lack of equipment, poor training, and bad management.
Things were so bad, the inspectors said, that receptionists were carrying out initial checks on patients arriving at A&E.
However, the watchdog still felt compelled to issue a number of warnings to the rest of the health service.
It said managers should not become obsessed with targets to such an extent that patient care is no longer the priority - as happened with Mid Staffordshire.
The report highlighted the use of a ward near to A&E which acted a "dumping ground" for patients so the hospital could meet the four-hour waiting time target.
It also said monitoring performance and comparing it to other NHS trusts was essential.
This is something the central command of the NHS at the Department of Health is expected to focus on in the coming weeks.
Monitoring exercise
Ten regional medical chiefs are currently being recruited to monitor the quality of care in hospitals across their patch, and report to the NHS medical director Sir Bruce Keogh.
There is also likely to be more pressure on hospitals to publish comprehensive death rates - something doctors have been particularly resistant to.
However, many of the issues raised in the report will also have wider resonance for the rest of the NHS.
During the period of excess deaths the trust was under severe pressure to save money, amid the furore over NHS deficits, and because of its desire to become a foundation trust - given to the elite performing hospitals in the health service.
In total 150 posts were cut in the end.
And while this was going on the local and regional bodies responsible for overseeing the hospital - primary care trusts and health authorities - were coping with structural reorganisation ministers had enforced, the watchdog said.
Elite status
And concerns are being voiced about how the NHS trust was granted foundation trust status in February 2008.
This was after the alerts were raised, and just two months before the investigation was formally launched.
The Healthcare Commission said Monitor, the body which is in charge of giving trusts foundation status, had not even asked if the watchdog had any concerns.
However, the report also makes uncomfortable reading for the Healthcare Commission.
The watchdog was not even the first to notice something could be wrong, despite the availability of evidence of higher death rates dating back to 2003.
In recent years the trust has also climbed the ratings ladder, becoming "good" in 2007.
At the time the Healthcare Commission assessed the core standards at the trust and judged them to have been met.
Light touch
The Healthcare Commission since its launch has pioneered a light touch to regulation.
Gone are the days when inspectors would patrol the corridors of hospitals, and in their place is a system largely based on self-assessment and feedback.
But Sir Ian rejected any suggestion that the watchdog was culpable.
He said the very fact the report had now been published was proof the watchdog's approach to inspection was working.
He said: "Everyone else was fobbed off. We alone stayed the course."
But whatever the truth, it seems the fall out from Mid Staffordshire has only just begun
stafford appalling
Patient care tops hospital pledge
Progress at Stafford Hospital will be reviewed in August |
Managers at a hospital which was criticised for "appalling failings" have pledged to spend millions of pounds improving patient care.
Stafford Hospital outlined planned improvements in areas such as staffing levels, facilities and equipment as part of its Confidence in Care plan.
It follows recommendations by health experts and the former regulator.
The Healthcare Commission had reported that patients died needlessly at the hospital between 2005 and 2008.
It said the death rate during those three years was much higher than expected with the hospital seeing an extra 400 deaths than the average for the health service.
'Patient safety'
A follow-up government review earlier this year said care was now safe, but problems still existed over staffing and equipment.
In response, Mid Staffordshire NHS Foundation Trust has set out its future goals in seven key areas.
These include reviewing clinical staffing levels, increasing the involvement of the public and patients in the trust's "transformation" as well as establishing procedures to ensure it was meeting high expectations and was accountable through regular reviews.
Eric Morton, interim chief executive of the trust, said: "Our top priorities must be the safety and experience of every single patient who comes through our doors, and the effectiveness of the care we offer."
The trust said most of its 107 improvement goals would be achieved within eight months.
The Care Quality Commission, which replaced the Healthcare Commission, is to review progress made at the hospital in August
ministers appalling
Minister sees hospital protesters
The hospital was criticised for "appalling" emergency care |
Campaigners who want a public inquiry into Stafford Hospital have met health secretary Andy Burnham.
The Cure The NHS group presented hundreds of patient case notes to Mr Burnham when they visited Whitehall.
Stafford Hospital was severely criticised by the Healthcare Commission watchdog in a report in March.
It said "appalling" emergency care resulted in patients dying needlessly. The government has rejected calls for a public inquiry, however.
Former health secretary Alan Johnson said there was no need because the Healthcare Commission report had been comprehensive.
Campaigners now hope his successor Mr Burnham can be convinced to hold an inquiry.
Julie Bailey, from Cure The NHS, said: "I am really hoping and confident that he will understand why we have been campaigning for so long and so hard and determined for a public inquiry."
nhs lack of care
Basic care 'lacking' in hospitals
The vast majority of patients receive good care, nurses' leaders say |
A patient lobby group is demanding an urgent review of basic hospital care after highlighting accounts of "appalling" NHS standards.
Relatives told the Patients Association how their loved ones, often elderly people, were left lying in faeces and urine and were not helped to eat.
The group's president Claire Rayner, an ex-nurse, called for "bad, cruel nurses" to be struck off.
The government said the cases were unacceptable but not representative.
The report focused on 16 stories from relatives of patients in England, which the association says are just a few of "hundreds and hundreds" of similar reports from across the UK.
It says self assessment allows too many health authorities to ignore problems that have been raised and is calling for regulator the Care Quality Commission to intervene.
Soiled bedding
The association insists accounts used in the report were reviewed critically before publication as it was aware complaints do "not necessarily reflect the reality".
But it stressed nearly all the accounts were concerned not about treatment but basic nursing and domiciliary care.
The Patients Association noted the latest inpatient survey found 43% rated the service they received as excellent, a significant increase from the previous year.
It is important to note this is not representative of the picture across the NHS. The NHS treats millions of people every day and the vast majority of patients experience good quality, safe and effective care Chris Beasley Government chief nursing officer |
But it stressed the 2% who deemed the service poor had not changed between 2002 and 2008, and that while the proportions were small they still represented thousands of patients.
Earlier this year, a report from the Healthcare Commission - now replaced by the Care Quality Commission - detailed grave lapses in standards of care at the Mid Staffordshire NHS Trust.
Families described "Third World" conditions, with some patients drinking water from vases and lying for hours in soiled bedding.
"Whilst Mid Staffordshire may have been an anomaly in terms of scale the Patients Association knew the kinds of appalling treatment given there could be found across the NHS," said Katherine Murphy, the association's director.
"This report removes any doubt and makes this clear to all. Two of the accounts come from Stafford, and they sadly fail to stand out from the others."
She said the stories were often about the most vulnerable elderly.
"We hope this report also encourages other people to get in touch with us and tell their stories. We plan to continue publishing accounts until we can be confident that every patient is secured dignity in their care," she continued.
Two per cent is too many but we are concerned that this might undermine the public's confidence in the world-class care they can expect to receive from the NHS Dr Peter Carter Royal College of Nursing |
Relatives described how they found their loved ones dehydrated or lying in faeces, blood and urine, and told of problems in getting help from nurses. They also told how patients were left with sandwiches or drinks in packaging which they could not open.
Ron Kirk said his father, Leslie, was admitted to hospital in October 2007, having suffered a stroke, but that his treatment at the hands of some nurses amounted to cruelty.
His father had been fitted with the wrong catheter, leaving him in pain, but nurses took away his bedside alarm because they thought he was "pressing it too often", Mr Kirk said.
Claire Rayner said: "I am sickened by what has happened to some part of my profession of which I was so proud. These bad, cruel nurses may be - probably are - a tiny proportion of the nursing work force, but even if they are only one or two per cent of the whole they should be identified and struck off the Register."
Good 'overshadowed'
Government chief nursing officer Chris Beasley said: "All patients deserve the highest quality of care from the NHS and the poor care received in these cases is simply unacceptable."
But she said this was not representative of the picture across the NHS.
"The NHS treats millions of people every day and the vast majority of patients experience good quality, safe and effective care - the Care Quality Commission's recent patient experience survey shows 93% of patients rate their overall care as good or excellent."
The CQC said the registration system it was introducing for trusts next year would ensure they met key quality standards.
"It is absolutely right to highlight that standards of hospital care can vary from very good to poor," said chairman Barbara Young.
"Many people are happy with the care they receive, but we also know that there are problems.
"Matters related to the dignity of care are of particular concern to patients and their families.
"And poor basic nursing is a recurring theme in organisations that perform badly.
"I am in no doubt that many hospitals need to raise their game in this area."
Dr Peter Carter, chief executive of the Royal College of Nursing (RCN), said it would not condone nurses who behave in ways "that are contrary to the principles and ethics of the profession".
But he added: "This report is based on the 2% of patients who feel that their care was unacceptable.
"Two per cent is too many but we are concerned that this might undermine the public's confidence in the world-class care they can expect to receive from the NHS.
"Furthermore it could also dampen the morale of the millions of staff who work tirelessly to help their patients."
Wednesday, 26 August 2009
immune Lymph system
Lymph System
The lymph system is most familiar to people because doctors and mothers often check for "swollen lymph nodes" in the neck. It turns out that the lymph nodes are just one part of a system that extends throughout your body in much the same way your blood vessels do. The main difference between the blood flowing in the circulatory system and the lymph flowing in the lymph system is that blood is pressurized by the heart, while the lymph system is passive. There is no "lymph pump" like there is a "blood pump" (the heart). Instead, fluids ooze into the lymph system and get pushed by normal body and muscle motion to the lymph nodes. This is very much like the water and sewer systems in a community. Water is actively pressurized, while sewage is passive and flows by gravity.Lymph is a clearish liquid that bathes the cells with water and nutrients. Lymph is blood plasma -- the liquid that makes up blood minus the red and white cells. Think about it -- each cell does not have its own private blood vessel feeding it, yet it has to get food, water, and oxygen to survive. Blood transfers these materials to the lymph through the capillary walls, and lymph carries it to the cells. The cells also produce proteins and waste products and the lymph absorbs these products and carries them away. Any random bacteria that enter the body also find their way into this inter-cell fluid. One job of the lymph system is to drain and filter these fluids to detect and remove the bacteria. Small lymph vessels collect the liquid and move it toward larger vessels so that the fluid finally arrives at the lymph nodes for processing.
immune system overview
The most obvious part of the immune system is what you can see. For example, skin is an important part of the immune system. It acts as a primary boundary between germs and your body. Part of your skin's job is to act as a barrier in much the same way we use plastic wrap to protect food. Skin is tough and generally impermeable to bacteria and viruses. The epidermis contains special cells called Langerhans cells (mixed in with the melanocytes in the basal layer) that are an important early-warning component in the immune system. The skin also secretes antibacterial substances. These substances explain why you don't wake up in the morning with a layer of mold growing on your skin -- most bacteria and spores that land on the skin die quickly.
Your nose, mouth and eyes are also obvious entry points for germs. Tears and mucus contain an enzyme (lysozyme) that breaks down the cell wall of many bacteria. Saliva is also anti-bacterial. Since the nasal passage and lungs are coated in mucus, many germs not killed immediately are trapped in the mucus and soon swallowed. Mast cells also line the nasal passages, throat, lungs and skin. Any bacteria or virus that wants to gain entry to your body must first make it past these defenses.
Once inside the body, a germ deals with the immune system at a different level. The major components of the immune system are:
- Thymus
- Spleen
- Lymph system
- Bone marrow
- White blood cells
- Antibodies
- Complement system
- Hormones
immune system
How flesh bug fools immune system
The parasites are carried by the Sand fly |
Scientists have shown how flesh-eating parasites responsible for the disfiguring tropical disease leishmaniasis dupe the immune system.
The parasites produce a gel which the latest study shows can fool specialised immune cells into feeding rather than killing them.
It is hoped the findings could aid development of a vaccine for a disease which affects 12m people a year.
The study, led by Imperial College London, appears in PLoS Pathogens.
This study may well prove to be of significant benefit Dr Tim Paget Medway School of Pharmacy |
Leishmaniasis is a serious problem in tropical and sub-tropical countries.
Symptoms include disfiguring and painful skin ulcers, and in severe cases the infection can also spread to the internal organs.
Patients with the infection often suffer from social exclusion because of their disfigurement.
There is currently no vaccine against the disease and, although treatments are available, they are not always effective and access is limited in many areas.
Leishmania parasites are carried in the guts of sandflies.
The parasites produce a gel which turns into a plug which effectively blocks up the fly's digestive system.
When an infected fly bites a human it regurgitates this gel plug, which enters the skin alongside the parasites.
The latest study - carried out on mice - shows that the plug acts to entice immune cells called macrophages to the bite site.
Macrophages usually kill invading pathogens by eating and digesting them.
But the gel persuades macrophages to engulf the parasites, and feed them rather than digest them.
This happens within the first few days following infection, enabling the parasites to establish themselves and infect the skin.
Lead researcher Dr Matthew Rogers said previous studies might have failed to explain leishmaniasis infection because they injected parasites directly into tissue without including the gel plug.
He said: "Our research shows that leishmania parasites are very cunning - they make their own gel to control the human immune system so they can establish a skin infection."
Synthetic version
Dr Rogers said work suggested a synthetic version of the gel might offer protection against infection.
The researchers found that the gel attracted 108 times more macrophages to the bite site than a saline solution.
They also showed that the number of parasites that survived the first 48 hours following infection, and the number of host cells that were infected, were both eight times higher when the gel was present.
Dr Tim Paget, an expert in microbiology at Medway School of Pharmacy, said there had been several clinical trials of potential vaccines, but they had generated mixed results.
He said: "This study may well prove to be of significant benefit.
"It is known that vaccines raised against proteins from the saliva from the sandfly can give protection to infection.
"Thus it is very likely that this gel could be used a target for the development of a novel vaccine.
"However, like all new findings, the benefits from this work are likely to be long term."
drug cancer link
Tamoxifen
Tamoxifen is given to most women with breast cancer |
Long-term use of a common breast cancer drug may hike the risk of developing a deadly second tumour, a study suggests.
Tamoxifen, given to thousands of British women, prevents tumours being fuelled by the sex hormone oestrogen, and stops them returning after surgery.
But a US study links use of the drug to a four-fold raised risk of developing a more aggressive, difficult-to-treat tumour, not dependent on oestrogen.
However, women are strongly advised not to stop taking tamoxifen.
Women should be reassured that the benefits of taking hormone-blocking drugs, such as tamoxifen, after their first diagnosis of breast cancer far outweigh any potential risks Dr Alison Ross Cancer Research UK |
Experts stress any risks of taking the drug are far outweighed by the benefits.
They said the odds of developing a second, non-hormone sensitive tumour remained very low.
Each year around 45,500 women in the UK are diagnosed with breast cancer and 12,000 die from the disease.
Around two thirds of breast cancers are sensitive to the hormone oestrogen.
Tamoxifen become the "gold standard" treatment for these hormone-sensitive tumours, although in recent years newer drugs have started to be preferred.
The latest study, by the Fred Hutchinson Cancer Research Center in Seattle, looked at long-term use of the drug among more than 1,000 women.
The researchers, writing in the journal Cancer Research, found that tamoxifen reduced the chances of oestrogen-positive breast cancer returning by 60%.
But they also found that five or more years of treatment was associated with a 440% increase in the chance of an aggressive, non-hormone sensitive tumour appearing in the opposite breast.
These tumours can be particularly difficult to treat.
Many women in the UK cease tamoxifen treatment after five years to avoid side effects, but several thousand woman have been on the drug for a longer time.
Risks and benefits
Lead researcher Dr Christopher Li said: "It is clear that oestrogen-blocking drugs like tamoxifen have important clinical benefits and have led to major improvements in breast cancer survival rates.
"However, these therapies have risks, and an increased risk of ER negative (oestrogen receptor negative) second cancer may be one of them.
"Still, the benefits of this therapy are well established and doctors should continue to recommend hormonal therapy for breast cancer patients who can benefit from it."
Professor Jack Cuzick, head of Cancer Research UK's Centre for Epidemiology, Mathematics and Statistics at Queen Mary, University of London, stressed that tamoxifen had a proven track record.
He said: "There is overwhelming evidence that tamoxifen, and newer more effective hormone blocking treatments, prevent far more recurrences, new breast cancers and cancer-related deaths than they might stimulate."
Professor Cuzick said some of the non-hormone sensitive tumours recorded in the study may have started out as hormone-sensitive, but had been kept at bay by tamoxifen treatment.
Dr Alison Ross, senior science information officer at Cancer Research UK, said: "Women should be reassured that, based on extensive scientific evidence, the benefits of taking hormone-blocking drugs, such as tamoxifen, after their first diagnosis of breast cancer far outweigh any potential risks.
"More research will be needed to confirm the possible link between its long-term use and the relatively rare occurrence of an aggressive form of the disease in the other breast."
Tuesday, 25 August 2009
balanced diet
Low-carb dieters base meals on meat dishes |
Low-carb slimming diets may clog arteries and increase the risk of heart attacks and strokes, a study suggests.
Diets based on eating lots of meat, fish and cheese, while restricting carbohydrates have grown in popularity in recent years.
But the Beth Israel Deaconess Medical Center found such eating habits caused artery damage in tests on mice.
The researchers and independent experts both agreed a balanced diet was the best option.
Low-carb diets have attracted a lot of attention and controversy after a surge in interest in them in the 1990s.
It appears that a moderate and balanced diet, coupled with regular exercise, is probably best for most people Anthony Rosenzweig, lead researcher |
The Israeli team decided to investigate their impact on the cardiovascular system after hearing of reports of people on the diets suffering heart attacks.
They fed the mice three different diets - a standard mouse type, a western diet which was high in fat, and a low-carb, high-protein version, the journal Proceedings of the National Academy of Sciences reported.
The low-carb diet did not affect cholesterol levels, but there was a significant difference on the impact on atherosclerosis - the build-up of fatty plaque deposits in the arteries that can lead to heart attacks or strokes.
After 12 weeks, the mice eating the low-carb diet had gained less weight, but developed 15% more atherosclerosis than those on the standard mice food. For the western diet group there was 9% more atherosclerosis.
The team could not be certain why the effect was seen, but thought low-carb diets may affect the way bone marrow cells effectively clean arteries of fatty deposits.
Adverse effects
Lead researcher Anthony Rosenzweig said the findings were so concerning to him that he decided to come off the low-carb diet he was following.
He added: "Our research suggests that, at least in animals, these diets could be having adverse cardiovascular effects.
"It appears that a moderate and balanced diet, coupled with regular exercise, is probably best for most people."
Joanne Murphy, from the Stroke Association, agreed following a balanced diet was the best advice.
"We know that foods such as red meat and diary products, which are high in protein, also contain high levels of saturated fat. These fats then cause the build up in the arteries."
But she added the research was still at an early stage and she wanted to see more work done on the subject.
Ellen Mason, from the British Heart Foundation, said it was difficult to apply the findings to humans.
But she added: "Low-carb, high-protein diets are not considered as healthy as eating a balanced diet, which is good for health because we get the different nutrients our body needs by eating from the different food groups every day."
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