Monthly Archives: February 2013

Rare Diseases Are Common

They may be called rare diseases, but collectively, they afflict nearly one in ten Americans. That’s because there are over 7,000 different conditions that each affect fewer than one-tenth of one percent of people in the United States. For those people, however, the rarity of the disease can make a serious problem into an intractable one. The rarity of these conditions makes it difficult to find treatments or cures.

Most rare diseases are largely or entirely genetic; 80 percent have been traced to genetic causes. Infectious diseases seldom restrict themselves to a small population, and conditions caused by environmental factors pop up as often as people are exposed to those causes, however, some diseases are rare in the United States because they are caused by a microbe or allergen or environmental source not normally found in this country. The diseases themselves resist treatment, but all the more so because the small number of patients makes information scarce, meaning these conditions are difficult for medical researchers to study—and illnesses that affect only a few people are often a low research priority.

Many rare diseases are hard to detect, because they share symptoms with more common conditions, and diagnostic procedures lead doctors to those first. In addition, because so little is known about them, symptoms are easy to miss or misinterpret. All illnesses have more and less common symptoms, but when the disease itself is rare, doctors may not see the rarest symptoms more than once or twice in a generation. In fact, there are diseases with only one or two known cases in recent decades, and it is obviously impossible to tell whether the symptoms those patients display would qualify as “typical” if the illness were more common.

The good news is that more and more research is being done on rare diseases. Public opinion is increasingly focused on gaps and deficiencies in healthcare, so doctors are more motivated to look for ways to deal with even diseases that affect few people. Moreover, government policy is moving towards treating these conditions, and inducements are being created to look into them.

The Ugly Truth About Heart Disease And Cholesterol

The link between cholesterol and heart disease is well known, but often poorly understood. There are three kinds of cholesterol, and they have very different effects on health. “Good” high-density lipoproteins (or HDL) are beneficial and reduce your risk of developing heart disease; “bad” low-density lipoproteins are harmful and raise it. The less commonly discussed third type, triglycerides, are known as “ugly” cholesterol, is even more harmful than LDL—high triglyceride levels can make your risk of heart disease rise threefold.

Triglycerides are the body’s way of storing extra calories—basic fat, which is in fact a type of cholesterol. Researchers believe triglycerides may be directly responsible for coronary artery disease. Triglyceride levels are measured in mg/dL; anything below 150 mg/dL is considered normal, but the American Heart Association recommends maintaining less than 100 mg/dL.

Ischemic heart disease is caused by narrowing of the arteries leading to the heart. Triglycerides and LDL cholesterol gather in the blood vessels and cause them to become narrower and less flexible, meaning they are less able to deliver needed oxygen to the heart. This causes damage to the heart muscle and keeps it from functioning properly.

There are drug therapies that can lower triglycerides, but the best way to keep yourself at a healthy triglyceride level is with an overall healthy lifestyle. In particular, be careful about excess calories, avoid sugar and saturated fats, get plenty of exercise, drink alcohol in moderation if at all, and remove trans fats and partially hydrogenated oil from your diet entirely.

Other risk factors for heart disease include a family history of the condition, high blood pressure, a stressful lifestyle, and diabetes. If you have any of these it is particularly important to make the lifestyle changes that lower your triglyceride, levels. You should also consider other changes that protect your heart, such as quitting smoking, cutting down on salt, washing your hands, and taking measures to avoid infections.

Tracing Concussion Damage

A chemical in the brain called a tau protein is an important part of cognitive function, at least in moderation. Ordinarily, these proteins strengthen and stabilize the neurons, allowing mental signals to travel along their designated paths. However, sometimes there’s an excess of these tau proteins. Often the result of a traumatic brain injury, such as a concussion, the tau proteins get in each other’s way, tangling up in the neurons and blocking the impulse pathways they’re supposed to support. This causes the effects of post-concussion syndrome, and can have long term effects on cognitive function. These proteins are the link between concussion and conditions such as ganglioglioma, Pick’s disease, and chronic traumatic encephalopathy.

Now a new scanning technique has found these proteins in the brains of former football players with chronic traumatic encephalopathy. Because of the nature of the game, brain injuries are all too common among NFL players, but previously the tau buildup was only detectable in an autopsy; this is the first time it has been seen in a living patient. This means that diagnosing and even predicting chronic traumatic encephalopathy can be done more easily. By looking for tau proteins in the brain, neurologists and sports-medicine practitioners will be able to find the effects of trauma as they develop, before any symptoms appear, and take appropriate preventative measures; or start treatment in time to slow or even halt cognitive decline.

Chronic traumatic encephalopathy is often found in boxers, football players, and other athletes who see a lot of violent trauma in their careers. Soldiers are also prone to the condition after concussive blasts in combat situations. It is one of a number of conditions called tauopathies, a category that includes Alzheimer’s disease as well as other forms of dementia. Symptoms of chronic traumatic encephalopathy include disorientation, confusion, slowed movement, staggered gait, slurred speech, and poor judgement, made worse by a deficiency in insight that makes it difficult for the patient to recognize what’s happening. Treatment protocols are focused on using medication to reduce the number of tau proteins to normal levels.

Low Vitamin D Linked With Breast Cancer

New studies are shining a light on how breast cancer risk can be better assessed. Researchers have found a link between low levels of vitamin D and getting breast cancer at a young age. In particular, women at risk for breast cancer before menopause were found to have low levels of the vitamin in the three months immediately prior to diagnosis. It is believed that this corresponds to the period when the tumor is beginning to settle in, and vitamin D blocks this process. Vitamin D is generally gotten from sunlight, though it is also found in supplements and in some foods.

Although approximately one in eight women will develop breast cancer, it’s far more likely in women over 55; premenopausal breast cancer is comparatively rare. However, obesity and radiation exposure both increase the odds at any age. Women who have a first child after age 35 are also at increased risk. Also raising your odds are a personal or family history. If you had breast cancer, you’re more likely to get it again; if a family member has had it, you’re more likely to get it. This is because of genetic mutations that make someone prone to the disease. People at risk for breast cancer are advised to get plenty of exercise and maintain a healthy weight, to limit alcohol consumption, and to get tested frequently. In some cases women at particularly high risk can get preventative medical or even surgical treatments.

Vitamin D may also be helpful in preventing breast cancer, at least in younger women with high risk. Doctors estimate that if all women made sure to get optimal levels of vitamin D, there would be 58,000 fewer cases of breast cancer every year in the United States. The optimal level, however, is nearly twice the minimum amount considered normal, though far less than what is deemed excessive. Sunlight and supplements are the best sources for vitamin D, though it’s generally added to milk as well. In particular, moderate sun exposure—taking care not to burn—allows your body to produce enough vitamin D with no risk of overproduction, and keeps your breast cancer risk down. Have your doctor test your vitamin D levels, and make sure you’re getting enough.

Stress and Schizophrenia

Schizophrenia, perhaps the prototypical mental illness, is connected to stressors growing up, researchers say. Scientists at Johns Hopkins have found that stress hormones in mice seem to affect brain development in individuals who are susceptible based on genetics. In these individuals, the hormones can lead to the changes associated with schizophrenia. The scientists believe the same effects are likely to be found in humans.

People with schizophrenia—a collective term for a group of closely related disorders—perceive reality abnormally. It affects the brain and the central nervous system, according to neuroimaging studies. Schizophrenia has different types of symptoms. The familiar delusions and hallucinations, and similar symptoms, are called positive symptoms, things found in schizophrenia but not the general population. Schizophrenics also typically show what are referred to as negative symptoms, areas in which schizophrenics show a deficiency, such as social withdrawal, apparent emotionlessness, lack of motivation, and lack of attention to hygiene. The third kind are cognitive symptoms, such as unusual inattentiveness, or trouble understanding, processing, or remembering information.

In the Johns Hopkins study, researchers induces stress in mice by isolating them during a key period of their mental development, equivalent to human adolescence. In most of the mice, this had little effect in the long term. However, in mice bred to have a genetic predisposition to mental illness-like symptoms, the isolation produced those symptoms. Moreover, the mice persisted in the behaviors characteristic of mouse mental illness even when reunited with their peers, meaning the isolation produced permanent changes.

The team speculated that social isolation and stressful circumstances in human teenagers have similar effects on people predisposed to mental illness. Another risk factor for schizophrenia is prenatal exposure to certain toxins. Malnutrition and some viruses can also lead to schizophrenic symptoms. Because of the genetic factor, people with a family history are especially likely to be subject to the condition.

Keeping Your Sight As You Age

Most people lose some degree of visual acuity as they get older, but sometimes it goes beyond the ordinary effects of aging. People who, as they get older, are less and less able to see things in the center of the visual field, find themselves having difficulty adapting to low light levels, have trouble reading because the words are blurry, have increasing problems recognizing faces, or have other related symptoms may have a condition called age-related macular degeneration, in which the center of the retina decays over time. The condition tends to run in families. Macular degeneration is the leading cause of blindness in Americans over 50.

Why people develop macular degeneration, and why it progresses further in some patients than in others, is not clearly understood. Regular eye examinations can help catch the condition early on, though it’s very difficult to predict its incidence or course. There are some studies that suggests that aspirin may play a role in the development of the disease; however, the risk is extremely low even among patients on aspirin therapy.

The damage done by macular degeneration can’t be reversed, but it can be slowed. If the condition is advanced in one eye, vitamins seem to help protect the other one. Scientists are looking into blocking the production of certain proteins in the eye that are associated with the “dry” form of the disease. The more severe “wet” form that patients sometimes develop is typically treated with medications to stop the overgrowth of blood vessels in the eye that accelerates vision loss. Laser surgery can also be used.

It’s never too late to take steps to avoid age-related macular degeneration. If you smoke, it’s one of the many areas in which quitting will improve your health. Keeping drinking down to no more than one alcoholic drink per day also helps. In addition, eating a diet with limited trans fats and plenty of fish and green vegetables and getting enough exercise, and staying fit and keeping your blood pressure down, will benefit your eyes as well as your heart. Recent research has also found some benefit from carnosic acid, found in rosemary, in preventing the condition.

Twitter and Health

Public health, the science of epidemics and large-scale prevention efforts, rests on data collection. Knowing what diseases are spreading, what strains, where, how, how quickly– these are the weapons on the arsenal of the protectors of the health of the people. The internet is particularly good for this. Since it connects millions of people, around the world, in real time, it’s a great way to find out what people are doing, how they’re feeling, and what’s happening to them, including illness. In fact, Google is harnessing its Web data analysis capabilities to measure and track flu trends.

If Google can do this with the data it has access to, it stands to reason that Twitter, the microblogging service on which more than half a billion users share their thoughts and activities on an almost minute-by-minute basis. And indeed, epidemiologists and other researchers are using a variety of techniques to sift through these posts and dig out information on people’s health. Looking at 5,000 public messages per minute, computer scientists at Johns Hopkins University have gotten a picture of patterns of flu outbreaks that match the maps generated by the government– but faster, in minutes rather than the two weeks required by the Centers for Disease Control and Prevention

The hardest part, experts say, is to separate discussions from reports, and metaphorical from actual illnesses and symptoms. For example, “fever” can mean high body temperature, but it can also mean extreme enthusiasm. Certain bodily responses have been compared to sneezing, but do not indicate sickness. And people will talk about fear of a disease, or precautions against a disease, or rumors or a disease, or having had a disease in the past, and these need to be distinguished from current instances for the data to be useful.

Already, some interesting patterns have emerged. A private company that has also been working on tracking disease through public internet postings found that the densely populated corridor between Hartford, Connecticut and Washington, D.C., is a hotbed of disease activity, and that disease mentions go up around events such as the Super Bowl that draw large crowds of tourists.

Follow Medex on Twitter: @MedexSupply.

Preventing Prenatal Infections

Around one in four expectant mothers carries a bacterium called group B streptococcus. The bacterium, which is generally found in the intestines or the vagina, is harmless in adults, but can harm the developing fetus. It can cause miscarriage or stillbirth, lead to preterm delivery, and cause significant, sometimes fatal health problems after the child is born. These effects can in some cases last a lifetime.

The good news is that the incidence of these effects is going down. However, it is still a problem that affects a substantial number of infants and newborns every year—one in 1,200 newborns under a week old show signs of infection, along with a number of stillbirths and miscarriages. Moreover, women who are found to be carrying the bacterium in their first pregnancies are more likely to be carrying it again subsequently.

One common affect, when the child is born otherwise healthy, is meningitis. Over the past quarter century, more of these children have been surviving meningitis caused by group B strep, but it still reverberates. In a recent study, nearly half of subjects who, as infants, had been diagnosed with group B streptococcal meningitis were found to have some kind of lasting neurological damage or impaired functioning. Nearly one in five of those subjects had severe damage, such as cerebral palsy or impaired vision or hearing.

It is recommended that pregnant women get tested for group B strep at around 36 weeks, since it’s almost always asymptomatic in women. That is the best time to deal with it—the use of antibiotics during labor drops the risk of infecting the baby from one in 200 to one in 4,000, a 95 percent reduction. These antibiotics are given intravenously if there’s a positive test or if the mother has had group B strep in the past, if the baby is at least three weeks premature, if labor is taking longer than 18 hours, or if the mother develops a fever during labor. After birth, if there’s some reason to suspect a group B strep infection, a blood or spinal fluid test can be done, though it takes most of the week.

Loops

The bowel sometimes forms loops, twisting around on itself to form an obstruction called a volvulus. Doctors classify volvulus into different types on the basis of where in the gastrointestinal tract the twisting occurs:

  • Volvulus of the small intestine
  • Volvulus of the cecum
  • Sigmoid colon volvulus
  • Volvulus of the transverse colon
  • Volvulus of the splenic flexure
  • Gastric volvulus
  • Ileosigmoid knotting

The splenic flexure type, at a natural bend in the colon near the spleen, is the rarest kind of volvulus. The most common is in the S-shaped sigmoid colon near the bottom of the gastrointestinal passageway. Eating a single large meal rather than several smaller meals throughout the day, particularly over a period of time, can increase the likelihood of developing volvulus. All volvuli cause bowel obstruction and stop blood flow to the affected area, leading to gangrene. Left untreated, volvulus will gradually destroy the intestine due to buildup of fluid and lack of blood; the condition is eventually fatal.

Symptoms include abdominal pain, tenderness, and swelling; nausea and vomiting, occasionally with stool in the vomit; constipation or diarrhea; and fatigue. Treatment starts with a nasogastric tube, which is inserted through a nostril to suck out digested food in order to relieve pressure. Surgery is generally necessary to untwist the bowel, though except in severe cases, it can be done laparoscopically, through a small incision. However, if necrosis has occurred, open surgery is generally needed to remove the dead tissue.

Antibiotics from Pandas and Curry

Curry and pandas have a perhaps surprising link with human health. It involves a class of chemicals called cathelicidin-related antimicrobial peptides. These chemicals are common in mammals, having been isolated in humans, monkeys, mice, rats, rabbits, guinea pigs, pigs, cattle, sheep, goats and horses—and now, pandas. Cathelicidins play an important role in the immune system, helping it fight off unfamiliar infectious agents.

In fact, a cathelicidin may be partly responsible for the popularity of curry and similar foods. One important source of the substance is the spice turmeric, which has been used for centuries in Indian cooking and is in yellow mustard. Turmeric is rich in a type of cathelicidin called cucumin. In addition to its immune benefits, curcumin is a natural anti-inflammatory that research suggests may help fight prostate cancer.

In laboratory mice, curcumin stopped the spread of prostate cancer by inhibiting the inflammation that is frequently characteristic of the disease. Not only that, but curcumin produces no side effects and is safe for most patients, meaning anyone diagnosed with prostate cancer can be recommended curcumin, even if there’s not yet any indication that the cancer is starting to metastasize.

Another type of cathelicidin, AM, was isolated from the blood of the giant panda late last year. In panda blood, cathelicidin-AM fights infections, including fungal infections, helping protect the endangered animals from some of the most common illnesses. The natural antibiotic and immune component appears to be effective against a wide variety of bugs.

Fortunately, researchers have already figured out how to produce synthetic cathelicidin-AM in the lab, so they can leave the 1,600 pandas remaining. Demand may be high pretty soon—rese3archers say not only does cathelicidin-AM fight even drug-resistant bacteria, it does so in a way that doesn’t encourage the development of further resistance, making the compound a superweapon in the arms race between people and disease.