Common fungus no allergy friend

Alternaria is one of the most common airborne funguses. Found indoors and out, it is typically the fungus most prevalent in the daily “pollen count” done by this office.

It has been known for many years to be a major contributor to respiratory allergy, both upper airway (rhinitis) and lower airway (asthma).

New research done by the National Heart and Lung Institute in the U.K. has revealed a second mechanism whereby it causes respiratory mischief. In addition to its “allergenic irritability,” Alternaria wreaks further havoc because it prompts protease-activated receptors found in human airwaves to release the inflammatory molecule IL-33 (interleukin-33). IL-33 is an extremely vitriolic molecule and causes both airway inflammation and airway remodeling (scarring).

Epidemiologic studies have found a strong correlation between environmental Alternaria levels and hospital admissions for asthma.

In some studies it is believed to cause 30 percent of asthma exacerbations.

The thunderstorms of summer and fall lead to dispersion of Alternaria spores, plus all molds tend to be higher in autumn.

The British researchers are looking at ways to try to abrogate the IL-33 release.

Allergic to one drug, maybe to all – or maybe not

Cephalosporins constitute a large family of antibiotics. They are “kissing cousins” to the penicillin family, but are unique in their own right. Until recently it was thought that if a person was allergic to one cephalosporin, they would be allergic to the entire family.

Several research groups have questioned this conventional wisdom. Most recently the Italian Ministry for University Research did a large population study on this issue. They did both skin testing and clinical challenges (giving the patient a test dose) with several hundred patients known to be allergic to one type of cephalosporin.

As it turns out, most of these individuals were found to be skin-test negative and patient-challenge negative to at least one different cephalosporin. The basic cephalosporin molecule consists of a ring structure with variable side-chain molecules. The greater the difference in the side-chain molecule,

the greater the likelihood of no cross-reacting allergy.

The Italian researchers concluded that – especially in people with limited choices for available antibiotics and who have a known cephalosporin allergy – it is worth testing them to a cephalosporin with a different side-chain structure so as to find a safe alternate therapy.

Dear Doc: My wife says if I don’t wear my hearing aids I’ll get dementia. Could she be right?

The answer to your question is yes; and, furthermore, I personally always follow the mantra: “Happy, wife; happy life.”

Unfortunately, hearing loss is very frequent: 3 in 10 over age 60; 1 in 6 aged 41-69 (Baby Boomers), and 1 in 14 aged 29-40 (Generation X).

However, untreated hearing loss leads to loss of gray matter (the thinking part of our brains). Also, the extra effort used by people straining to hear interferes with normal cognition. Finally, the social isolation that can occur from hearing loss leads to mental stagnation.

Neuroscientists have actually found that correcting hearing loss in individuals already diagnosed with dementia slows the progression of the disease.

Two other reasons to listen to your wife have to do with heart disease and the risk of falling. The Framingham Heart Study found a correlation between low-frequency hearing loss and heart disease. As it turns out, having uncorrected hearing loss leads to higher levels of adrenal gland output which can elevate heart rate and blood pressure.

The CDC (Centers for Disease Control and Prevention) found that a 25-decibel hearing loss increased the risk of falling three fold. Hearing loss makes an individual less aware of their overall environment, thus increasing fall risk. Straining to hear and process auditory input distracts the brain from other activities such as maintaining balance.

Finally, cochlear (the hearing part of your ear) disorders can impact vestibular (the balance part of the ear) function.

Bottom line – listen (pun intended) to your wife.

Water sports draw attention

The School of Sports Science in Australia recently completed a research study on Olympic athletes regarding aquatic sports and asthma.

They found the highest incidence of asthma in aquatic athletes as compared to all other Olympic athletes. Among aquatic athletes pool swimmers had the most asthma, and among categories of swimmers it was the endurance swimmers who again had more asthma than the sprint and intermediate swimmers.

After pool swimmers, the water sports associated with asthma in decreasing order of frequency were synchronized swimming, water polo, diving and then open-water swimming.

Also the researchers found that asthma was more common in all groups if they trained in indoor pools as opposed to outdoor pools. They posit that the pool chloramines are the cause of the airway irritation and that indoor pools trap higher levels of the chloramines.

The researchers were very careful to endorse the overall health benefits of swimming as an excellent form of exercise. They simply want people to be aware of the asthma issue so it can be properly addressed by the swimmers’ physicians.

Roach dust has value? Who knew?

Just when you think the wacky world of immunology can’t get any crazier, new research turns another corner. Readers of this newsletter have previously been exposed to the hygiene hypothesis of allergy; that is, because we are “so clean,” our idle immune systems find a mischievous outlet in the form of allergic diseases.

Now researchers at the University of Texas have looked into the role exposure to cockroach dust might play in this regard. As it turns out, exposure to cockroach dust serves as a proxy to microbial exposure as a protective factor in reducing the risk of children developing allergy and asthma.

The benefit was quite dramatic as it led to about a 50-percent reduction in the development of allergy.

More asthma research yields hopeful new controls

For quite some time it has been known that calcium plays a major role in muscle contraction. A number of calcium-altering medicines are used to help heart problems and hypertension by relaxing the smooth muscle found in the heart and arteries. Now there may be an application to asthma.

Smooth muscle is also found in our bronchial tubes; constriction of this muscle that occurs through proteins called calcium-sensing receptors causes asthma.

A recent British study examined the use of a class of drugs used to treat osteoporosis called calcilytics. These drugs were administered to asthmatic mice with dramatic results: the drugs blocked the action of calcium-sensing receptors and thus, prevented the smooth muscle constriction.

The scientists are now starting human studies. This research is very compelling as it offers a mechanism to control asthma that has never before been available.

Zithromax new hero in infant RSV?

The major cause of bronchiolitis in infants, and not infrequently the major cause of subsequent chronic asthma in these children, has been the topic of recent exciting research at Washington University.

The culprit – RSV (Respiratory Syncytial Virus) – seems to succeed because is elicits such a strong inflammatory response in the airways of its tiny victims that they never fully recover.

In the past efforts have been made to try to reduce this inflammation by the use of both inhaled and systemic steroids; however, neither of these have been of any benefit.

Because the antibiotic Zithromax is known to reduce inflammation in adults with COPD and bronchiecstasis, the Washington University researchers decided to try it in RSV. Their study compared the use of Zithromax to placebo in infants with RSV. The outcome was dramatic. The children who received the Zithromax were more than 50 percent less likely to develop chronic asthma than the control group.

This correlated with the fact that the Zithromax group had much lower levels of inflammation in laboratory tests than the control group.

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