Understanding Acne

 

There are many myths about what causes acne. Some people blame foods for their outbreaks. Some think that dirty skin causes it. But there’s little evidence that either has much effect on most people’s acne.

People of all races and ages get acne. About 4 of every 5 people between the ages of 11 and 30 have outbreaks at some point. It’s most common in adolescents and young adults. Although acne is usually not a serious health threat, it can be upsetting, and severe acne can lead to permanent scarring. Fortunately, for most people, acne tends to go away by the time they reach their 30s.

Acne begins in the skin’s oil glands. The oils travel up a canal called a follicle, which also contains a hair. The oils empty onto the skin surface through the follicle’s opening, or pore.

The hair, oil and cells that line the narrow follicle can form a plug and block the pore, preventing oil from reaching the skin’s surface. This mix of oil and cells allowsbacteria that normally live on the skin to grow in plugged follicles. Your body’s defense system then moves to attack the bacteria and the area gets inflamed.

If the plugged follicle stays beneath the skin, you get a white bump called a whitehead. If it reaches the surface of the skin and opens up, you get a blackhead. It’s not because of dirt; the oil becomes black on the skin’s surface when it’s exposed to air. Both whiteheads and blackheads may stay in the skin for a long time. Eventually, the wall of the plugged follicle can break down, leading to pimples, or zits.

One important factor in acne is an increase in certain hormones during puberty. These hormones cause the oil glands to enlarge and make more oil. Hormone changes related to pregnancy or starting or stopping birth control pills can also cause acne.

Studies suggest that you can inherit a tendency to develop acne from your parents, so genes likely play some role. Stress doesn’t cause acne, but research has found that for people who have acne, stress can make it worse.

Certain drugs are also known to cause acne. Greasy cosmetics, for example, can alter the cells of the follicles and make them stick together, producing a plug. If you have acne, try oil-free cosmetics. Choose products labeled noncomedogenic (meaning they don’t promote the formation of closed pores).

If you have acne, don’t rub or touch your pimples. Squeezing, pinching or picking at them can lead to scars or dark blotches. Gently wash your face with a mild cleanser twice a day—and after heavy exercise. Don’t use strong soaps or rough scrub pads; they may make the problem worse. It’s also important to shampoo your hair regularly. If you have oily hair, you may want to wash it every day.

Several over-the-counter medicines can treat mild acne. It may take up to 8 weeks before you notice an improvement. For more severe acne, talk to your doctor about the options.

Researchers continue to work on developing new drugs to treat acne. They’re also trying to better understand the causes of acne so they can explore new remedies. In the meantime, there are several available treatments that may help.

Article Obtained from: NIH

Insights into How HIV Evades Immune System

 

New details about how antibodies bind the human immunodeficiency virus (HIV) may help bring researchers closer to creating an effective HIV vaccine.

Image: Artist’s illustration of HIV.

Vaccines typically work by triggering the immune system to produce antibodies that help to beat infections. But most antibodies can't latch onto and neutralize HIV. The proteins on the surface of the virus mutate rapidly and change shape continuously. They're also covered with immune-evading carbohydrates called glycans.

NIH scientists recently focused on one of these HIV surface proteins, called gp120. HIV uses what are called envelope spikes, or trimers, to bind and infect cells. These spikes support three gp120 molecules, which HIV uses to grip and to gain entry into the cells it infects.

Researchers had a major breakthrough in 2007 when they identified an unchanging region of gp120 as a potential site of viral weakness. Further studies, however, found that the vast majority of antibodies that bound to this site don't block HIV from infecting cells. Dr. Peter D. Kwong at the Vaccine Research Center of NIH's National Institute of Allergy and Infectious Diseases (NIAID) headed a research team investigating how the virus resists these antibodies.

The scientists revealed the virus's trick in the November 20, 2009, edition of Science. They determined the crystal structures of two poorly neutralizing human antibodies in complex with gp120. These antibodies bind to gp120, they found, with a key portion of the protein swung in or flared out. When swung in or flared out, gp120 doesn’t fit into the shape required to form the functional viral spike. In contrast, when a rare neutralizing antibody called b12 binds, gp120 is in the shape required to form the functional spike.

Most antibodies to gp120 don't bind its functional form, the researchers found. That's why they can't effectively neutralize HIV. “When an antibody binds to something that's quite flexible, it induces or selects shapes that are not necessarily appropriate for function,” Kwong explains. “In the functional viral spike, gp120 assumes a very specific shape. Most antibodies can't see that particular shape.”

This study highlights the challenge of generating HIV-neutralizing antibodies. Most gp120 appears as inactive single molecules or in viral debris. Future vaccines will have to generate antibodies to target the site of vulnerability on gp120 in the envelope spike. “We now know the factors guarding the site,” Kwong says. “The next step is learning how to overcome those barriers.”

Kwong points out that people with HIV can generate antibodies to this site—in fact, that's how it was discovered in the first place. “We just haven't yet learned how to do that by vaccination,” he says, “but we're working on it.”

—by Harrison Wein, Ph.D.

Antibodies Protect Against HIV in Mice

 

Researchers have devised a gene transfer technique in mice that, with a single injection, protects the immune cells that HIV targets. With further development, the approach may prove effective at helping to prevent HIV infection in people.

Image: An illustration of the virus used to deliver broadly neutralizing antibodies against HIV. Courtesy of Alejandro Balazs, California Institute of Technology.

Most vaccines work by triggering the immune system to produce antibodies to help beat back infections. But a vaccine for HIV has been elusive. Proteins on the surface of HIV mutate rapidly, changing shape and preventing most antibodies from latching onto the virus.

Scientists have discovered several antibodies that can neutralize HIV. They've gained important insights into how they bind to the virus and why they're effective. But designing a vaccine that prompts the human immune system to generate such antibodies and mount an effective attack remains a difficult challenge.

A team of researchers led by Drs. Alejandro Balazs and David Baltimore at the California Institute of Technology decided to pursue a different strategy—one that doesn't require the immune system to generate antibodies. Their work was partly supported by NIH's National Institute of Allergy and Infectious Disease (NIAID). They described the approach, called vectored immunoprophylaxis, in the November 30, 2011, advance online edition of Nature.

The scientists began with a virus capable of expressing high levels of full-length human antibodies when injected into muscle. They modified the virus by inserting the genes that code for an HIV-neutralizing antibody called b12. When the virus was injected into mouse leg muscle, the mice produced high levels of antibodies for at least a year.

The researchers next tested whether the technique could protect against HIV. Mice aren't susceptible to HIV, so the researchers used specialized mice with human CD4 cells, the immune cells that HIV targets and infects. After exposure to the virus, mice expressing b12 antibodies showed none of the CD4 cell loss that control animals did.

The researchers tested other antibodies known to neutralize a broad range of HIV strains. Another antibody called VRC01, which was identified by scientists at NIH, produced results similar to b12. Both antibodies protected CD4 cells against HIV doses 100-fold higher than the levels that would infect most animals. This protection would be well beyond that needed to prevent HIV infection in humans.

“Normally, you put an antigen or killed bacteria or something into the body, and the immune system figures out how to make an antibody against it,” Balazs explains. “We've taken that whole part out of the equation.”

The team is now developing a plan to test the method in human clinical trials. “If humans are like mice, then we have devised a way to protect against the transmission of HIV from person to person,” says Baltimore. “But that is a huge if, and so the next step is to try to find out whether humans behave like mice.”

—by Harrison Wein, Ph.D.

NIH scientists find a potential new avenue for cancer therapies

Recent findings in mice suggest that blocking the production of small molecules produced in the body, known as epoxyeicosatrienoic acids (EETs), may represent a novel strategy for treating cancer by eliminating the blood vessels that feed cancer tumors. This research is the first to show that EETs work in concert with vascular endothelial growth factor (VEGF), a protein known to induce blood vessel growth. Together, EETs and VEGF promote metastasis, or the spread of cancer, by encouraging the growth of blood vessels that supply nutrients to cancer cells.

The research team comprised of scientists from the National Institute of Environmental Health Sciences (NIEHS), which is part of the National Institutes of Health, and several other institutions, published its data online in the Dec. 19 issue of The Journal of Clinical Investigation.

Preclinical research suggests that patients with a variety of vascular conditions, such as diabetes, hypertension, inflammation, stroke, and heart attack may benefit by increasing their EET levels, because the compounds cause blood vessels to dilate and reduce tissue inflammation and cell death. However, previous work has also demonstrated that EETs make tumor cells grow faster and cause them to migrate and become metastatic. Darryl Zeldin, M.D., NIEHS scientific director and author on the paper, said he believed that human metabolism has to achieve a certain harmony in regard to EETs.

"The body has to produce enough EETs to maintain a healthy cardiovascular system without promoting cancer. It has to balance the double-edged sword just right," Zeldin said.

To find out how EETs encourage the development of cancer, the team created two mice strains, one with high levels of EETs and one with low levels of EETs.

"The mice with higher EETs developed more metastatic tumors compared to the mice with lower EETs," Zeldin said. "Often, the tumor itself will produce more EETs, which can speed up tumor growth and its subsequent spread, but our analysis demonstrated that the EETs produced by the surrounding tissues encouraged tumor growth and migration."

Matthew Edin, Ph.D., a research fellow in Zeldin’s group, is one of the authors on the paper and helped develop the mice strains. He said EETs directly lead to the creation of new blood vessels, also known as angiogenesis, which the cancer cells need in order to receive oxygen and nutrients to grow. He equated the process to what happens when a builder begins constructing a new housing development.

"One of the first things construction crews have to do is build the roads, so that materials and workers can be transported to the site," Edin said. "In cancer, EETs accelerate the road building, allowing the housing development to expand quickly."

According to Dipak Panigrahy, M.D., an author on the paper and a research associate at the Dana-Farber/Children’s Hospital Cancer Center, Boston, EETs have a potent stimulatory effect promoting cancer growth and metastasis, a process that could be effectively inhibited using novel antagonists, such as EEZE, which are compounds that interfere with this pathway in mice. EEZE has not been approved for human use, and is only used for research.

"EEZE is structurally similar to EETs, but it blocks the effect of EETs and dramatically slows tumorigenesis," Panigrahy explained.

Mark Kieran, M.D., Ph.D., another author of this collaborative study and also from Dana-Farber, commented on the importance of the research.

"The identification of an old pathway studied for many years in cardiovascular disease has found a new role in regulating cancer growth and metastasis, the primary causes of cancer related deaths," he said. "With these findings, opportunities to better understand the underlying mechanisms that drive cancer, and thus the development of effective therapies for their treatment, moves one step closer to a reality."

Inter-Agency Task Teams on Children and HIV and AIDS

 

Lock it Up: Medicine Saftey in Your Home

Every year thousands of children are hospitalized—and some die—after taking medicine not meant for them. Teens share stolen prescription drugs at "pharm parties" and toddlers are tempted by colorful pills that look like candy. In this Consumer Update video, FDA pharmacist Connie Jung explains how you can prevent harm by locking your medicine up

Ten Tips to Prevent an Accidental Overdose

For a medicine to work for you—and not against you—you’ve got to take the right dose.

Many over-the-counter liquid medicines—such as pain relievers, cold medicine,

cough syrups, and digestion aids—come with spoons, cups, oral droppers, or syringes designed to help consumers measure the proper dose. These “dosage delivery devices” usually have measurement markings on them—such as teaspoons (tsp), tablespoons (tbsp), or milliliters (mL).

But the markings aren’t always clear or consistent with the directions on the medicine’s package. The Food and Drug Administration (FDA) has received numerous reports of accidental overdoses—especially in young children—that were attributed, in part, to the use of dosage delivery devices that were unclear or incompatible with the medicine’s labeled directions for use.

On May 4, 2011, FDA issued a guidance to firms that manufacture, market, or distribute over-the-counter liquid medicines. The guidance calls for them to provide dosage delivery devices with markings that are easy to use and understand.

Parents and caregivers can do their part, too, to avoid giving too much or too little of an over-the-counter medicine. Here are 10 tips:

1. Always follow the directions on the Drug Facts label of your medicine. Read the label every time before you give the medicine.
2. Know the "active ingredient" in the medicine. This is what makes the medicine work and it is always listed at the top of the Drug Facts label. Many medicines used to treat different symptoms have the same active ingredient. So if you're treating a cold and a headache with two different medicines but both have the same active ingredient, you could be giving two times the normal dose. If you're confused, check with a doctor, nurse, or pharmacist.
3. Give the right medicine, in the right amount. Medicines with the same brand name can be sold in different strengths, such as infant, children, and adult formulas. The dose and directions also vary for children of different ages or weights. Always use the right strength and follow the directions exactly. Never use more medicine than directed unless your doctor tells you to do so.
4. Talk to your doctor, pharmacist, or nurse to find out what mixes well and what doesn't. Medicines, vitamins, supplements, foods, and beverages aren’t always compatible.
5. Use the dosage delivery device that comes with the medicine, such as a dropper or a dosing cup. A different device, or a kitchen spoon, could hold the wrong amount of medicine. And never drink liquid medicine from the bottle.
6. Know the difference between a tablespoon (tbsp) and a teaspoon (tsp). A tablespoon holds three times as much medicine as a teaspoon. On measuring tools, a teaspoon (tsp) is equal to "5 mL."
7. Know your child's weight. Dosage amounts for some medicines are based on weight. Never guess how much to give your child or try to figure it out from the adult dose instructions. If a dose is not listed for your child's weight, call your health care professional.
8. Prevent a poison emergency by always using a child-resistant cap. Relock the cap after each use. Be especially careful with any medicines that contain iron; they are the leading cause of poisoning deaths in young children.
9. Store all medicines in a safe place. Some are tasty, colorful, and many can be chewed. Kids may think they’re candy. Store all medicines and vitamins out of your child's (and your pet's) sight and reach. If your child takes too much, call the Poison Center Hotline at 800-222-1222 (open 24 hours a day, 7 days a week) or call 9-1-1.
10. Check the medicine three times before using. For any medicine, it is always good practice to first, check the outside packaging for such things as cuts, slices, or tears. Second, once you’re at home, check the label on the inside package to be sure you have the right medicine and that the lid and seal are not broken. Third, check the color, shape, size, and smell. If you notice anything unusual, talk to a pharmacist or other health care professional before using.

Key Hearing Proteins Identified

 

Researchers have found what appear to be 2 key components of the long-sought-after mechanotransduction channel in the inner ear—the place where sound waves are transformed into the electrical signals that the brain recognizes as sound.

Sensory cells in the inner ear called hair cells are crucial for transforming sound into electrical signals. Hair cells also underlie our sense of balance. Sitting atop hair cells are tiny bristly structures called stereocilia. Microscopic tethers connect the tips of shorter stereocilia to the sides of adjacent taller stereocilia. Most scientists believe that as the stereocilia move, the tethers open ion channels—tiny openings in the cell that let electrically charged molecules (ions) pass in and out. The ions rushing inside begin an electrical signal that travels to the brain.

While researchers have gained many insights into mechanotransduction, the ion channels involved have remained elusive. A team of researchers led by Dr. Andrew J. Griffith of NIH's National Institute on Deafness and Other Communication Disorders (NIDCD) and Dr. Jeffrey R. Holt of Harvard Medical School decided to focus on 2 proteins. Griffith and other collaborators had previously found that mutations in the TMC1 gene cause hereditary deafness in both humans and mice. The TMC1 protein sequence suggests that it could span the cell's outer membrane and act as a channel. Another protein, TMC2, has a similar structure. The scientists deleted both genes in mice. Their findings appeared on December 1, 2011, in theJournal of Clinical Investigation.

Mice with no functional copies of TMC1 or TMC2 had the classic behaviors of dizzy mice—head bobbing, neck arching, unstable gait and circling movements. They were also deaf. The TMC1 deficient mice were deaf as well, but had no balance issues. Mice without TMC2 had no problems with hearing or balance.

The scientists examined when the TMC1 and TMC2 genes are expressed (turned on) in the inner ears of mice. The 2 genes were expressed from birth in hair cells in both the cochlea, which is responsible for hearing, and the vestibular organs, which are responsible for balance. When mice were a week old, TMC2 appeared to be turned off in the cochlea but not in the vestibular organs. TMC1 continued to be expressed in mature cochlear hair cells. Taken toghter, these findings suggest that TMC1 is essential for hearing, but TMC2 is not. For balance, however, TMC2 can substitute for TMC1.

In laboratory tests, hair cells lacking functional TMC1 or TMC2 had no detectable mechanotransduction currents, even though the rest of the cells' structure and function appeared normal. By using a gene therapy technique that adds proteins back into cells, the researchers were able to restore transduction to both vestibular and cochlear hair cells. This finding suggests that it might be possible to reverse these genetic deficits.

The researchers found that TMC1 and TMC2 cluster at the tips of the stereocilia, where one might expect to see proteins that play a prominent role in mechanotransduction. In future work, the scientists intend to explore how TMC1 and TMC2 interact with each other as well as with other known proteins at the stereocilia tip.

A Key to Choosing Healthful Foods: Using the Nutrition Facts on the Food Label

Have you ever read the Nutrition Facts label on food packages and wondered: serving sizes, percentages, daily values – what do they all mean? Well, you're not alone. Many consumers would like to know how to use the Nutrition Facts label more easily and effectively — and help is finally here. Use this information to make quick, informed food choices that contribute to healthy lifelong eating habits for you and your family.

Product Info and "Daily Values"

The Nutrition Facts label is divided into Two Main Areas:

Sections 1-5 provide product-specific information (serving size, calories, and nutrient information). These vary with each food product.

Section 6 is a Footnote with Daily Values (DVs). The footnote provides information about the DVs for important nutrients, including fats, sodium and fiber. The DVs are listed for people who eat 2,000 or 2,500 calories each day.

• The amounts for total fat, saturated fat, cholesterol, and sodium are maximum amounts. That means you should try to stay below the amounts listed.
• The DVs for total carbohydrate and dietary fiber daily represent the minimum amounts recommended for a 2,000-calorie diet. This means you should consume at least this amount per day for each of these nutrients.
• The footnote is only found on larger labels, and does not change from product to product.

Details on the Daily Value

3 Easy Ways to Use the % Daily Value

1. Look at highs and lows.
   The %DV gives you a framework for deciding if a food is high or low in a nutrient. Use the Quick Guide to %DV: 5% or less is low and 20% or more is high.

   Compare products – Use the %DV to compare one food product or brand to a similar product. Make sure the servings sizes are similar, especially the weight (e.g., gram, milligram, ounces) of each product so you can see which foods are higher or lower in nutrients.

2. Evaluate claims.
   So you don't have to memorize definitions, use the %DV to help you quickly distinguish one claim from another, such as "reduced fat" vs. "light" or "nonfat." Just compare the %DVs for Total Fat in each food product to see which one is higher or lower in that nutrient. There is no need to memorize definitions. This works when comparing all nutrient content claims, e.g., less, light, low, free, more, high, etc.
3. Make dietary trade-offs.
   Make dietary trade offs using the %DV. For example, when a food you like is high in saturated fat, select foods that are low in saturated fat at other times of the day.

---

What's On the Label?

1. Serving Size

   This section is the basis for determining number of calories, amount of each nutrient, and %DVs of a food. Use it to compare a serving size to how much you actually eat. Serving sizes are given in familiar units, such as cups or pieces, followed by the metric amount, e.g., number of grams.

2. Amount of Calories

   If you want to manage your weight (lose, gain, or maintain), this section is especially helpful. The amount of calories is listed on the left side. The right side shows how many calories in one serving come from fat. In this example, there are 250 calories, 110 of which come from fat. The key is to balance how many calories you eat with how many calories your body uses. Tip: Remember that a product that's fat-free isn't necessarily calorie-free.

3. Limit these Nutrients

   Eating too much total fat (including saturated fat and trans fat), cholesterol, or sodium may increase your risk of certain chronic diseases, such as heart disease, some cancers, or high blood pressure. The goal is to stay below 100%DV for each of these nutrients per day.

4. Get Enough of these Nutrients

   Americans often don't get enough dietary fiber, vitamin A, vitamin C, calcium, and iron in their diets. Eating enough of these nutrients may improve your health and help reduce the risk of some diseases and conditions.

5. Percent (%) Daily Value

   This section tells you whether the nutrients (total fat, sodium, dietary fiber, etc.) in one serving of food contribute a little or a lot to your total daily diet.

   The %DVs are based on a 2,000-calorie diet. Each listed nutrient is based on 100% of the recommended amounts for that nutrient. For example, 18% for total fat means that one serving furnishes 18% of the total amount of fat that you could eat in a day and stay within public health recommendations. Use the Quick Guide to Percent DV (%DV): 5%DV or less is low and 20%DV or more is high.

6. Footnote with Daily Values (%DVs)

   The footnote provides information about the DVs for important nutrients, including fats, sodium and fiber. The DVs are listed for people who eat 2,000 or 2,500 calories each day.

—The amounts for total fat, saturated fat, cholesterol, and sodium are maximum amounts. That means you should try to stay below the amounts listed.

                     

From the U.S. Food and Drug Administration         

Eat for a Healthy Heart

 

Making healthy food choices is one important thing you can do to reduce your risk of heart disease—the leading cause of death of men and women in the United States.

According to the American Heart Association, about 80 million adults in the U.S. have at least one form of heart disease—disorders that prevent the heart from functioning normally—including coronary artery disease, heart rhythm problems, heart defects, infections, and cardiomyopathy (thickening or enlargement of the heart muscle).

Experts say you can reduce the risk of developing these problems with lifestyle changes that include eating a healthy diet. But with racks full of books and magazines about food and recipes, what is the best diet for a healthy heart?

Food and Drug Administration nutrition expert (FDA's) Barbara Schneeman says to follow these simple guidelines when preparing meals:

• Balance calories to manage body weight
• Eat at least 4.5 cups of fruits and vegetables a day, including a variety of dark-green, red, and orange vegetables, beans, and peas.
• Eat seafood (including oily fish) in place of some meat and poultry
• Eat whole grains—the equivalent of at least three 1-ounce servings a day
• Use oils to replace solid fats.
• Use fat-free or low-fat versions of dairy products.

The government’s newly released “Dietary Guidelines for Americans 2010” also says Americans should reduce their sodium intake. The general recommendation is to eat less than 2,300 mg. of sodium a day. But Americans 51 or older, African-Americans of any age, and people with high blood pressure, diabetes, or chronic kidney disease should restrict their intake to 1,500 mg. The government estimates that about half the U.S. population is in one of those three categories.

 

Packaged and Restaurant Food

Schneeman, who heads FDA's Office of Nutrition, Labeling, and Dietary Supplements, says one way to make sure you’re adhering to healthy guidelines is by using the nutrition labels on the packaged foods you buy.

“Product labels give consumers the power to compare foods quickly and easily so they can judge which products best fit into a heart healthy diet or meet other dietary needs,” Schneeman says. “Remember, when you see a percent DV (daily value of key nutrients) on the label, 5 percent or less is low and 20 percent or more is high.”

Follow these guidelines when using processed foods or eating in restaurants:

• Choose lean meats and poultry. Bake it, broil it, or grill it.
• In a restaurant, opt for steamed, grilled, or broiled dishes instead of those that are fried or sautéed.
• Look on product labels for foods low in saturated fats, trans fats, and cholesterol. Most of the fats you eat should come from polyunsaturated and monounsaturated fats, such as those found in some types of fish, nuts, and vegetable oils.
• Check product labels for foods high in potassium (unless you’ve been advised to restrict the amount of potassium you eat). Potassium counteracts some of the effects of salt on blood pressure.
• Choose foods and beverages low in added sugars. Read the ingredient list to make sure that added sugars are not among the first ingredients. Ingredients in the largest amounts are listed first. Some names for added sugars include sucrose, glucose, high fructose corn syrup, corn syrup, maple syrup, and fructose. The nutrition facts on the product label give the total sugar content.
• Pick foods that provide dietary fiber, like fruits, beans, vegetables, and whole grains.