Monthly Archives: September 2014

About Cystic Fibrosis

lungs-md

A single mistake on a single gene can cause serious medical problems. In fact, it is just such a mistake, the omission of a three-letter word from the genetic code, that causes cystic fibrosis, a congenital lung disease that also affects the digestive system, in 90 percent of the about 30,000 cases in the United States. This deletion, or any of the approximately 1,500 other mutations that can cause cystic fibrosis, can be inherited from other parent, but only causes disease when it is inherited from both. All these mutations have similar effects, mucus forms in the lungs, interfering with breathing and leaving the person prone to infection. Cystic fibrosis also causes poor growth, infertility, and a reduced lifespan.

In fact, some researchers are suggesting that the mutation is associated with two or more different illnesses. One is the disease commonly thought of as cystic fibrosis, in which unusually thick mucus is produced, coating the lungs and causing the respiratory symptoms associated with the disease; another, often considered harmless, is now believed to cause problems with the pancreas and digestive system, with the reproductive system, with the sinuses, or elsewhere in the body.

Thickened mucus is not the only reason people with cystic fibrosis are especially prone to lung infections. People with cystic fibrosis also have high rates of an infection called cepacia syndrome, which disrupts the immune response. Cepacia syndrome is also a disease in its own right, causing fever, pneumonia, and, often, death. However, there is new evidence emerging that cystic fibrosis itself causes damage to the immune system. People with cystic fibrosis are missing a crucial immune system molecule that makes it possible for the immune cells to identify pathogens, in order to be able to hunt them down and destroy them. When the pathogens go unrecognized, they are allowed into the body to cause harm.

Fortunately, there is good news. Scientists are reporting that cystic fibrosis patients born in 2010 have a longer expected lifespan than their predecessors. Overall, only about half of cystic fibrosis patients live to 40—itself an improvement on the days when few reached elementary school age—but improvements in treatment and management mean those born this decade are expected to make it well into their 50s.

Colon Cancer And Bacteria

colon-cancer

Gut microflora are a community of bacteria the live in the human digestive tract and help make digestion possible. Although these microflora are separate organisms from humans, they are usually harmless, and even beneficial. However they can also go wrong and cause disease. There bacteria are most beneficial in the proper balance—the negative effects of one group is canceled out by the actions of another. Imbalance leads to illness; for example, some of these bacteria prevent tumor growth in colon cancer, but others increase the growth rate. When the balance is thrown off, these bacteria can cause colon cancer to quickly get out of control.

Other things that hasten the growth of colon cancer is a protein called PLAC8. This PLAC8 protein has been linked with colon cancer for a long time, but the precise nature of the link was poorly understood until recently. While other proteins associated with cancer actually inhibit the body’s own tumor-fighting mechanisms. PLAC8 encourages tumor growth. It alters the interior of the colon so that it is easier for colon cancer to develop and spread. In particular, PLAC8 causes tumors to grow in an irregular, spiked shape, rather than the usual smooth shape; the spikes cause the cancer to be more aggressive, and grow more in the digestive tract.

Risk factors for colon cancer include a personal or family history of the disease, smoking, heavy alcohol use, and being over 50. In addition, people who are obese, who are sedentary, or who eat a high-fat diet are at heightened risk. In a study, health men with a body mass index in the obesity range were more likely to have polyps in screenings. That is why doctors are starting to focus on screenings for obese men, to catch colon cancer early on, when it is most responsive to treatment.

Obese men are also particularly advised to take measures to prevent colon cancer. Losing weight, getting more exercise, and eating more fiber and less fat is the most direct way to lower risk, but there is more that people can do. Low-dose aspirin, commonly used to prevent stroke and heart disease, can also reduce incidence of polyps.

Rabies

rabies

The 19th-century French chemist and microbiologist Louis Pasteur was prolific in his discoveries, but today, 119 years after he died at age 72, he is remembered primarily for a handful. Pasteur invented the food preservation process that bears his name. He is responsible for discoveries, such as the nature of bacteria, that established the field of microbiology; he was among the first scientists to apply that understanding to the question of how diseases are transmitted. And it was Louis Pasteur who developed the first vaccine for rabies, a usually fatal viral disease that causes inflammation in the brain.

Rabies is transmitted from animals to humans—and from animals to other animals—through saliva, which is mostly passed through bites. When an animal with rabies bites another animal, the virus is transmitted. One of the effects of rabies is a tendency to violence, including biting. Although dogs are both the prototypical vector and the most common worldwide, in the Americas, bat bites are actually more often the culprit. However, any small mammal could be carrying rabies. There are about 7,000 cases a year in the United States.

Prevention is best effective at the source, but often the animals that transmit the disease are feral if not actually wild, which presents an obstacle to finding and vaccinating all animals that could potentially spread rabies. That is why people are advised to avoid wild or feral animals when possible, and admire them from a distance. Even strays can be dangerous if they’ve been stray for a significant amount of time.

The reason there is such a focus on prevention is because there is no cure; if the disease is allowed to develop, it is almost certainly fatal. Fortunately, there is a certain amount of lag time between the bite and the disease taking hold during which measures can be taken that may save the patient’s life. Post-exposure prophylaxis can be used to try to ensure the disease never comes to pass. This involves cleaning the wound and administering rabies vaccine as soon as possible.

If symptoms do appear, there is still a slim possibility of saving the patient. A procedure called the Milwaukee Protocol, after the city where it was created, has been used with limited success, though the six patients who recovered since the procedure was created in 2004 is more than had recovered from rabies in all of human history until then. It involves anti-viral drugs administered to a patient in an induced coma.

Apnea And Weight

apnea

Sleep apnea is a condition in which a person briefly but repeatedly stops breathing at night. There are believed to be 40 million Americans with sleep apnea, but it is difficult to say because the condition is frequently undiagnosed. The biggest single cause of sleep apnea is being overweight obesity. In fact, an estimated three fourths of people with sleep apnea have no knowledge of their condition. However, obesity isn’t necessarily what leads to apnea. In fact, people with large necks frequently get it despite being of average weight—a man with a neck larger than 17 inches around, or a woman with a neck larger than 16 inches, is in danger regardless of weight.

A person with sleep apnea can’t get a good night’s sleep—as breathing intermittently stop, the person wakes up, not so completely as to experience this wakefulness, but enough to interfere with a proper rest. That means that the person never truly gets the benefit of the restorative properties of sleep, and wakes up in the morning still tired. As with any other type of sleep deprivation, this pattern can lead to poor focus, poor memory, and walking around in a fog. The breathing difficulties also mean loud snoring, which, is sometimes the only indication that anyone notices for quite some time. Apnea can also lead to sexual dysfunction and depression. Because the oxygen supply to the brain is being interrupted, sleep apnea can also cause stroke, high blood pressure, or heart problems.

While a thick neck is a predictor of apnea, weight is a more common contributing factor. Doctors recommend that patients who are showing signs of apnea—especially those who are formally diagnosed with the condition—lose weight. A recent study found that people with sleep apnea who cut calories over four months had lower blood pressure and fewer instances of apnea while sleeping. Another study found that people with sleep apnea also tend to have elevated blood sugar levels which is a precursor to type 2 diabetes. This is further evidence of a link between diabetes and sleep apnea, both conditions that have been found to be associated with obesity. Sleep apnea itself may be contributing to the blood sugar levels, the study suggested.

Vaccination And Pertussis

pertussis vaccine

Pertussis, or whooping cough, is a disease of the bad old days, now largely eradicated through vaccination—except that it’s making a comeback. It starts out resembling an ordinary cold, but "cough" is an understatement. A pertussis patient will cough constantly, sometimes to the point of nausea. It interferes with sleeping, eating, drinking, talking. Sometimes, the coughing leaves patients gasping for air, or they cough hard enough to break ribs. Whooping cough can last for months.

Thanks to vaccination, pertussis almost disappeared entirely. However, thanks to an increasing tendency for parents not to vaccinate their children, more and more children are getting the disease. The disease can be annoying in adults but fatal to babies, but in 1940, a vaccine was introduced, and within a few generations became a standard part of childhood.

In recent years, however, vaccination has begun to be perceived, wrongly, as dangerous, and the diseases such as pertussis that it prevents perceived, also wrongly, as harmless, and the numbers have accordingly gone up—30 percent over last year, according to the Centers for Disease Control and Prevention. In 21 states, whooping cough cases have more than tripled. That’s nearly as many states as require only a doctor’s note, or less, for an exemption from vaccination requirements. Marin County, California, which has among the highest vaccine exemption rates in the country, also has the second highest rate of whooping cough.

Refusal to vaccinate doesn’t affect only the unvaccinated children. When enough people in a community are immune to a disease, it is impossible for the disease to establish a foothold, protecting even babies too young to be vaccinated or the tiny minority in whom the vaccine itself was ineffective. This herd immunity, however, requires that 93 percent of the population receive the vaccine.

That’s why medical professionals are working on ways to ensure that more people are vaccinated. One approach is to give pregnant women the TDaP vaccine, which combines the vaccine for pertussis with those for tetanus and diphtheria, during the third trimester. This has been found to have no adverse effects on the mother or the fetus, and, once born, the baby starts out with temporary immunity during what would otherwise be the most vulnerable period of life.

Causes Of Asthma

inhaler

Childhood asthma is a complex condition with a number of causes. It affects about one in 11 children in the United States, and common factors are hard to find. There is believed to be an allergic component, with allergens such as pollen, dust mites, and pollutants serving as triggers. Children with autoimmune conditions often have asthma as well. There has been observed to be a link between asthma and obesity, but it isn’t clear whether obesity can be a contributing factor for childhood asthma, as it is in adults, or if asthmatic children are more prone to obesity, for instance because they are less able to exercise.

One factor that is known to contribute is stress—in particular, the mother’s stress during pregnancy. Prenatal maternal stress has been found to have a number of possible effects on the future child, such as premature birth, and resent research adds asthma to that list. Stress hormones are heightened in pregnant women as a matter of course, and experiencing stress raise the levels of these hormones further. These elevated hormones can affect the fetus. Stress hormones temporarily lessen the immune response, and so fetuses are more prone to react to allergens and other asthma triggers. One such trigger is secondhand smoke. Most mothers-to-be know not to smoke during pregnancy, but there’s also evidence that when the father smoked—even before conception—the child is more likely to develop asthma.

In recent years, researchers have begun to look at the psychology of asthma. The symptoms of asthma can often be intractable, and respiratory medicine is not always the whole story. That is why doctors are increasingly turning to the insights of psychology to try to determine what will make people with asthma feel better as a separate question from what it means for the condition itself. Asthmatic people are prone to psychological problems stemming from the limitations it imposes, and addressing that is important.

Managing the physical symptoms is also important. One interesting finding is that infants who sleep on animal fur are less prone to developing asthma. If that isn’t enough, experts recommend keeping the environment as dust-free as possible, but using air conditioning, filters, and dehumidifiers to keep the air dry, cleaning damp areas to keep mold at bay, and vacuuming and dusting regularly, especially if there are pets in the home.

The Battle Against Prostate Cancer

Prostate cancer is the leading cause of cancer death in the United States

Around two and a half million men have prostate cancer. Possibly more, because many people with the condition never even realize it. Like many forms of cancer, prostate cancer has few signs in its earliest stages. In fact, in one study, 80 percent of men who died of natural causes after age 70 had signs of undiagnosed, untreated prostate cancer. Patients may have trouble urinating, or urinate blood, or have other related symptoms in the later stages, but by then treatment is less likely to be successful. Because of its invisibility, prostate cancer is the second leading cause of cancer deaths in the United States.

Risk factors include being over 65, obesity, and a family history of the disease, and a study earlier this year found that vasectomy is linked to increased incidence of prostate cancer. Although it only leads to a small increase in the overall risk, men who have had vasectomies are as much as 20 percent more likely to get the most lethal forms of the disease. Ejaculation is known to reduce the risk, but vasectomy, which blocks off the tubes through which semen is ejaculated, nullifies this benefit.

Because of the lack of symptoms, regular screening is an important part of catching prostate cancer in it earliest stages, when it is most responsive to treatment. However, one obstacle to this necessary screening is depression, a condition notoriously underdiagnosed in men. Depressed men are less likely to receive medical care across the board; with prostate cancer, that means later diagnosis and less effective treatment.

Screening is especial;y important for men already at risk. The biggest risk factors are age and genetics. Researchers have found that while lifestyle factors—such as smoking and obesity—are important, genetics is far more of a determining factor. The biological children of people with prostate cancer as as much as twice as likely to get it themselves, regardless of lifestyle.

Scientists have also recently discovered the benefits of tomatoes for reducing susceptibility to prostate cancer. A study found that men can lower their risk of prostate cancer as much as 18 percent by eating tomatoes ten times a week. This is believed to be thanks to the antioxidant lycopene, A fruit- and vegetable-heavy diet is generally recommended to people at risk for prostate cancer, as well as fiber.

Fighting Food Poisoning

food safety

Each year, 325,000 people are hospitalized with some form of food poisoning of which there are over 250. In all, there are estimated to be 48 million cases of food-borne illness in the United States each year, but most cases never come to the attention of health care professionals, so the actual number is likely to be higher. Because there are so many kinds, experts say, it isn’t always clear even to people who are sick that they have suffered food poisoning. In addition, most cases of food poisoning are isolated incidents. Outbreaks, when two or more people experience similar symptoms after eating food from the same source, are what make the news, but mot cases of food poisoning aren’t outbreaks at all.

There are a number of different pathogens that can cause food poisoning. These include bacteria such as E. coli, salmonella, and campylobacter; chemicals called mycotoxins that are produced by mold and other fungi; parasites, such as nematodes; and viruses, such as hepatitis A and E and norovirus. In addition, viruses called enteroviruses infect bacteria that in turn infest spoiled food. The bacteria themselves may be harmless—though some types of bacteria that are harmful in themselves, such as some species of Clostridum, can also carry enteroviruses—but can infect humans from within their host bacteria even when those bacteria are killed.

So what foods are the biggest dangers? Meat and dairy are often thought of as the biggest sources of food poisoning, but if handled correctly—in particular, if they are cooked thoroughly and kept out of the "danger zone" between 40 and 140 degrees Fahrenheit—these foods are generally fairly safe. Melons and sprouts, however, are difficult to properly clean and are often eaten raw, and so present pathogens with a welcoming environment.

For packaged foods, people often rely on the expiration date as a guide to whether the food in the package is safe, but this is little more than an estimate based on the date of manufacture. Producers do their best to determine when food will spoil, but it’s not an exact science. However, some packaging manufacturers are working on technology that will make it possible for the package itself to indicate whether there are pathogens or mold on the food, providing more detailed information than a printed date.

Race And Sickle Cell

black-doctor-and-patient

Sickle cell disease is a genetic illness that causes chest and joint pain, anemia, poor blood circulation, and a tendency towards infection. The mutation responsible for the disease causes a flaw in the process of building red blood cells—rather than round and flexible, the cells are rigid and sickle-shaped, which is what gives the disease its name. The disease is present from birth, an symptoms begin to appear shortly thereafter. People with sickle cell often have vision problems and are at greater risk of hypertension and stroke.

When a disease is genetically linked, it tends to be more prevalent in certain populations and ethnic groups; in particular, sickle cell disease is mostly found in black communities. As a result, the ravages of the disease are often compounded by racism, including in treatment facilities—either the patients are overlooked, or the facilities themselves are neglected by politicians and philanthropists. This has an effect on the treatment these patients are able to receive. This, in turn, makes them skeptical that health care providers are on their side and willing to help them. As a result, sickle cell patients frequently get suboptimal care.

This is a particular issue with sickle cell because management of the disease is so complicated. Patients need regular blood transfusions from a young age—ideally from donors who are especially well-suited to match people with sickle cell—physical therapy to prevent the effects of poor circulation, regular screening for high blood pressure, and therapy to ward off kidney disease. Bone marrow transplants can help some patients; however, this is a dangerous and drastic measure and matches are hard to find, although researchers are looking into ways to broaden the pool of potential matches.

Scientists are also looking into gentler bone marrow transplant procedures that may be lower risk. Transplanted bone marrow is a source of stem cells, which can be used to create correctly shaped red blood cells, undoing the damage. The usual marrow transplant procedure starts with an intense course of chemotherapy to completely destroy the patient’s own bone marrow, which is then replaces with the donor’s. Recently, medical professionals have begun looking at partial transplant, which avoid the dangers of chemo. In initial testing, this has been successful, but there is larger-scale testing still to come.

Destigmatizing Mental Illness

StephenFry

Mental illness is nothing if not common. More than five percent of Americans have a major psychiatric illness, and 20 percent have some degree of mental health difficulty. Nonetheless, the stigma around mental health remains. In fact, it is one of the most dangerous aspects of psychiatric disease. The stigma—by preventing people from seeking treatment, by keeping them from telling their friends, family, or co-workers, by keeping them from seeking accommodation or even understanding—compounds the effects of the illness itself, adding isolation to the burdens patients must bear.

In fact, only about two in five mentally ill people seek treatment, and many of those drop out partway through. In a report by the Carter Center, former First Lady Rosalynn Carter wrote, "one does not work long on mental health issues before recognizing the additional hardships caused by stigma." The stigma, experts say, is self-perpetuating: as people hide their illnesses, the damaging stereotypes of the mentally ill are allowed to take root, thus further discouraging people from coming forward.

For example, the belief is commonly encountered that people with a mental illness are simply seeking attention. This belief is particularly strong when the person claims to have a particular mental illness, and may even have a formal diagnosis, but is not showing the symptoms people expect on the basis of media portrayals. However, people who are displaying classic symptoms may be regarded as mimicking those portrayals, in order to make their claims more convincing.

That is why more and more public figures—such as British actor and comedian Stephen Fry, whose struggles with bipolar disorder led to a mental breakdown in 1995 due to stage fright, during which he fled the country as well as the public eye—are going public with their mental illness stories. Fry has appeared in documentaries on the subject and is involved with a mental health charity in the United Kingdom that is focused on bringing these conditions out into the open.

Indeed, while society isn’t quite there yet, there are hopeful signs, little indicators that the stigma may be starting to lessen. A study in England completed earlier this year found that attitudes toward the mentally ill are improving, thanks in part to the work people such as Fry are doing, with respondents showing a greater understanding of and sympathy for mental illness.