Nicotine drug 'may slow dementia'
Nicotine-based drugs may help delay the moment a person with dementia has to enter a care home, say researchers.
Nicotine has toxic effects, and carries a strong risk of addiction, but scientists have shown it can also boost learning, memory and attention.
The effect is small, but it may help give dementia patients up to six extra months of independent living.
A team at King's College London have demonstrated the positive effects of nicotine in experiments on rats.
They showed that nicotine boosted the animals' ability to carry out a task accurately - particularly when they were also distracted.
When able to give full concentration, the animals responded correctly to stimuli about 80% of the time. Nicotine boosted the accuracy rate by about 5%.
However, when distracted, the animals' success rate fell to about 55%. In this case nicotine brought it back up to around the 85% level.
The King's team, based at the Institute of Psychiatry, studied the mechanisms which underpin the effects produced by nicotine.
They showed how proteins on the surface of cells respond to the compound, and pinned down the role of several key chemicals in the brain, including dopamine and noradrenaline.
It transpired that there are only subtle biochemical differences in the way nicotine stimulates the brain, and triggers addiction.
Several nicotinic drugs are already in development, but the King's team hopes its work will speed up the discovery of agents which give the brain a bigger boost than nicotine, with longer lasting effects.
Lead researcher Professor Ian Stolerman said: "Nicotine, like many other drugs, has multiple effects, some of which are harmful, whereas others may be beneficial.
"It may be possible for medicinal chemists to devise compounds that provide some of the beneficial effects of nicotine while cutting out the toxic effects."
Professor Stolerman stressed that the positive effects produced by nicotine were small, and would be of no benefit to most people.
However, he said they could potentially make a difference to dementia patients.
He added that the "cognitive boost" that many smokers experience from nicotine may contribute to the pleasure they get from their habit.
Professor Clive Ballard, of the Alzheimer's Society, said: "Although nicotine has therapeutic qualities, when it is absorbed through smoking the health risks outweigh the benefits.
"Smoking increases risk of vascular dementia, the second most common form of dementia and is associated with a number of other health risks.
"More research is now needed to find a safe and effective treatment for dementia, with the potential benefits of nicotine, but without the health risks."
Rebecca Wood, of the Alzheimer's Research Trust, agreed that people should not be tempted to smoke to try to ward off dementia. She said the best way to minimise risk was to eat a balanced diet and exercise regularly.
Professor Stolerman said there was no reason to believe that nicotine or smoking reduced the risk of getting dementia - it only helps to reverse symptoms.
It is estimated that 700,000 people in the UK live with dementia.
The research will be presented to a Federation of European Neuroscience Societies conference in Geneva.
FDA Reviews Safety of Autoimmune Disorder Drugs
United States health officials have started conducting a safety review of a class of drug we know as tumor necrosis factor (TNF) blockers, which is a widely prescribed medicine to treat autoimmune disorders such as juvenile rheumatoid arthritis, rheumatoid arthritis, and Crohn's disease.
This announcement did not come as a shock, since experts have long been debating the risk-benefit profile of the medications without coming to any consensus. Among the main concerns being investigated are whether the medications are associated with the development of cancers, primarily lymphoma, in children and young adults that are being treated for Crohn's disease and rheumatoid arthritis. The agency is studying about 30 reports of cancer in this younger age group submitted between 1998, after the first TNF blocker was approved, through April of 2008. Increased risk of infection has also been linked to the TNF blockers.
The chief of the division of rheumatology at The Montefiore Medical Center and Albert Einstein College of Medicine, Chaim Putterman, said, "I think it's a fair thing to say this is an area of ongoing concern that has not been resolved.... The drugs were approved in adults, and more drugs are coming out, and everyone would prefer an indication in children, so the FDA has decide to clear it. It has always been a concern, and it's something that should be clarified."
There are currently four TNF blockers that are approved in the United States: Remicade (infliximab), Cimizia (certolizumab), Humira (adalimumab), Enbrel (etanercept). Remicade has been approved to treat children with Crohn's disease. According to the Food and Drug Administration, the medications Enebrel and Humira were approved to treat children with juvenile rehumation arthritis.
TNF blockers work by dampening the immune system, which can become hyperactive in patients that have rheumatoid arthritis. All four medications have been approved for multiple indications, but the Food and Drug Administration are focusing mainly on Enbrel, Remicade, and Humira. According to the experts, these medications have clear benefits and have revolutionized the treatment of some of these diseases.
"One of the reasons that these medications have such a market despite the concerns is that they are so remarkably effective," Putterman said. " There are not only subjective benefits but a tremendous amount of objective evidence, not only in inflammation and patient symptoms, but also in disease progression. These dugs have really addressed a previously unmet need."
In the past 20 to 30 years, these medications have been probably the most important advance in the treatment of rheumatoid disorders. The have been shown to dramatically approve certain forms of crippling cases of arthritis and almost stop them. With these treatments, some people can go from being in a wheelchair to walking around. These medications are being used earlier and earlier because they are so good. The FDA is just being smart and remaining cautious.
The shown increase risk of cancer may be caused by other factors other than the medication. The signal for cancer in these patients has not been a dramatic one. Among the rheumatoid patients, there are more factors that can make interpretation more difficult. One of the main factors of rheumatoid arthritis patients, independent of the treatments, is that they have a higher risk of developing some cancers. In addition, some patients have been treated with methotrexate, a chemotherapy agent that has been known to be associated with lymphoma.
One study in 2006 reported that concerns about TNF blockers causing cancer were unfounded, which caused conflicting scientific evidence. But earlier this year, a new review of the research found that the risks might be real. TNF blockers play an important role in immune surveillance, and by blocking it you could interfere with the body's natural defense system. The Food and Drug Administration has made a request that markers of the TNF blockers approved for use in young adults and children supply the information about all of the reported cases of cancer in children and young adults taking the medications.
The study of a new medication called Cimizia will start in 2009 to look at all of the long-term risks. This study could take about a decade to complete. In the meantime, the Food and Drug Administration has asked that physicians weigh all the possible risks against the benefits when prescribing TNF blockers.
Medicine (Latin medicus, “physician”), the science and art of diagnosing, treating, and preventing disease and injury. Its goals are to help people live longer, happier, more active lives with less suffering and disability. Medicine goes beyond the bedside of patients. Medical scientists engage in a constant search for new drugs, effective treatments, and more advanced technology. In addition, medicine is a business. It is part of the health care industry, one of the largest industries in the United States, and among the leading employers in most communities.
While the ancient Egyptians were known to perform amputations and other types of surgery, precise surgical techniques did not begin to develop until Greek physicians used surgery in diagnosis and the study of human anatomy. In the 1500s French surgeon Ambroise Paré improved on the standard method of stopping major bleeding with cautery, or searing, by using forceps and stitches. It was not until after 1865, however, when Joseph Lister introduced the use of antiseptics in the treatment of wounds, that the death rate following major amputations dropped from 50 to 12 percent. Shown here are the contents of a case of amputation instruments dating from about 1800.
Disease has been one of humanity's greatest enemies. Only during the last 100 years has medicine developed weapons to fight disease effectively. Vaccines, better drugs and surgical procedures, new instruments, and understanding of sanitation and nutrition have had a huge impact on human well-being. Like detectives, physicians and other health care professionals use clues to identify, or diagnose, a specific disease or injury. They check the patient's medical history for past symptoms or diseases, perform a physical examination, and check the results of various tests. After making a diagnosis, physicians pick the best treatment. Some treatments cure a disease. Others are palliative—that is, they relieve symptoms but do not reverse the underlying disease. Sometimes no treatment is needed because the disease will get better by itself.
While diagnosing disease and choosing the best treatment certainly require scientific knowledge and technical skills, health care professionals must apply these abilities in imaginative ways. The same disease may present very different symptoms in two patients, and a treatment that cures one patient may not work on another.
At the turn of the 20th century, many men and women were feeble by age 40. The average American born in 1900 had a life expectancy of 47.3 years. Effective treatments for disease were so scarce that doctors could carry all their drugs and instruments in a small black bag. By the end of the 20th century, medical advances had caused life expectancy to increase to 76 years. Modern health care practitioners can prevent, control, or cure hundreds of diseases. People today remain independent and physically active into their 80s and 90s. The fastest-growing age group in the population now consists of people aged 85 and over.
This medical progress has been expensive. In 1998 Americans spent $1.1 trillion on health care, an average of $4,094 per person. In the same year, health care accounted for about 13.5 percent of the gross domestic product (GDP), about one-seventh of the country's total output. Spending has grown rapidly from earlier in the century. In 1940, for instance, the United States spent $4 billion on health care.