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Tiniest cells causing big misery in young and old

Tiniest cells causing big misery in young and old

An infection that previously was mostly seen in children, over the past 15 years has been showing up more frequently in older adults. With its extended incubation period (2-4 weeks), it is difficult to diagnose, and capable of emerging as bronchitis or pneumonia.

And it is caused by the smallest free-living organisms — Mycoplasma pneumoniae — that were originally thought to be viruses, but have been shown to be bacteria. Unlike most bacteria they lack a cell wall and are bounded by only a thin plasma membrane.

These unique properties extend to their clinical features. Hence, the individual patient can have an extended period of “feeling like they are getting sick, but not really being sure.” Then the steamroller hits, often presenting as bronchitis or pneumonia, along with symptoms in other areas: headache, muscle aches, arthritis and GI symptoms. It can also cause a very painful type of ear infection with blisters on the ear drum.

Because of its lack of a cell wall it’s very difficult to grow in a culture and can be “missed” by this test; a fairly accurate blood test exists. It may be best recognized by its slow onset with attendant non-respiratory symptoms. It does respond to a few specific antibiotics: tetracyclines, macrolides and fluoroquinolones.

New shingles vaccine? Not quite yet

New shingles vaccine? Not quite yet

The lead article in the New England Journal of Medicine last month was on a new shingles vaccine. The study involved 15,000 people over age 70 in 18 different countries.

Unlike the currently used shingles vaccine which uses a live virus, the new vaccine uses a single protein from the virus, along with an immune stimulator.

The new vaccine, which is called HZ/su (Herpes Zoster subunit) prevented shingles in 92% of the patients, and prevented the dreaded complication of shingles post-herpetic neuralgia in 88% of the patients. This compares to the prevention values of the current vaccine of 52% for shingles and 66% for neuralgia.

In addition to its better protection, it can be given to people who are immune-compromised by their illness or by chemotherapy. The current live virus vaccine cannot be used in these patients.

Disadvantages of the new vaccine are that it requires two shots given two months apart. Also, there is a high incidence (30% of recipients) of local and systemic reactions. Finally, although the vaccine looks very promising, it is not yet approved by the FDA. One issue the FDA is studying is if and when it should be given to people who have already received the currently available vaccine.

Q – Tips: Asthma and fracking

Q – Tips: Asthma and fracking

John Hopkins Epidemiologists have found that asthmatics who live in areas of the country where fracking is done have an increased incidence of hospital/ER-requiring flare-ups — that is four times greater than their counterparts not exposed to the environmental leak of natural gas.

Allergic clock might tick in our favor

Allergic clock might tick in our favor

Research scientists in Tokyo have been working on resetting the allergic clock in mice to lessen their tendency to allergy.

Our daily circadian clock, which is critical for many of our biological systems, is located in a special area in the hypothalamus of our brain called the light-sensitive central oscillator. It is programmed by the varying exposure to light and dark. In turn, it signals all the peripheral oscillators (clocks) found in individual cells throughout the body. This includes the allergy-causing mast cells.

This nerve signaling is done via the release of “clock” proteins that can activate or suppress the cell function. As it turns out, most mammals, including humans, are least likely to have allergy symptoms the first four hours of the new day, and more likely to have symptoms overnight. In fact, asthma is sometimes called the “nocturnal predator” because of this circadian tendency to flare at night.

The Tokyo researchers used small amounts of one of these “clock” proteins (called casein kinase) to keep the mouse mast cells in the low-reactive mode. It worked amazingly well to lessen both the severity and frequency of their allergic reactions. The next step in this research is to extend these findings to humans.

Caring for childhood eczema clearer

Caring for childhood eczema clearer

Just-published research of eczema in children – and the accompanying sleep interruption it causes the kids and their parents – has led to a recommended treatment.

University of Nevada researchers compared the benefit of antihistamines versus topical steroids to control the itch/scratching in children with eczema.

They found that both forms of therapy were effective. In fact, they were equally good in preventing sleep disturbance from nocturnal itch – a particularly vexing symptom for families because it causes significant loss of sleep.

And, because the children are unattended in bed, their scratching often causes significant trauma to their skin.  All but five percent of the Nevada study group responded positively to the use of antihistamines.

This led the researchers to recommend their use in all children with eczema

Dear Doc: Exercise-induced symptoms confusing

Dear Doc: Exercise-induced symptoms confusing

Dear Dr. K: Dear Dr. K.: My husband and I both have allergies and we are both triathletes. When we exercise my husband’s nasal congestion always improves, while mine seems to get worse. What’s going on?

The answer to your question is statistics.

Your husband is on the good side of statistics and you are on the bad side. What I mean is that in the majority of people with allergies exercise helps open the nasal passages. It does this by two main mechanisms: neurologic and chemical. In most persons, exercise increases preferentially the sympathetic nerves that control blood vessel size, constricting these blood vessels, and thus, improving nasal patency (being open or expanded).

Exercise also releases “adrenal-like” chemicals that exert the same effect on the nasal blood vessels.

In a small number of people, exercise preferentially stimulates the parasympathetic nerves, which dilate nasal blood vessels and cause congestion. This phenomenon is called exercise-induced rhinitis. It is similar to a related phenomenon in asthmatics called exercise-induced-bronchospasm.

One predisposing factor to exercise-induced-rhinitis is deviation of the nasal septum. Apparently, people with septal deviation have a chronic disparity in air flow through the two nostrils. For some reason, this makes the parasympathetic nerves more sensitive, and thus their adverse response to exercise.

Growing up on a farm can protect against allergies

Growing up on a farm can protect against allergies

 

It has been observed for many years that living on a farm reduces the risk for children to develop allergies and asthma. To better understand this protective effect, researchers at the University of Munich conducted a study of thousands of children from birth to age 6.

It turns out that a major protective factor was the consumption of unprocessed cow’s milk, as opposed to pasteurized milk.

Before addressing the milk issue, readers should know that growing up on a farm lessens the chance for allergies in general. This benefit is felt to be part of the hygiene hypothesis of allergy; that is, city dwellers who grow up in a “clean environment” have idle immune systems which allow the immune system to get into “allergic mischief.”

Farm children are exposed to a variety of animals, manure and dirt which keeps the immune system occupied and less likely to go into allergic mode.

The hygiene issue aside, farm children who drank boiled or pasteurized milk were not as “protected” from allergy as their young farm friends who drank raw milk.

As it turns out, the difference is that pasteurization reduces polyunsaturated fats (PUFAs) that are protective. These same PUFAs are dietary precursors for natural anti-inflammatory mediators made by our immune systems.

Children with high PUFA intake make lots of these natural anti-inflammatory molecules and benefit from the protection against allergic/asthmatic inflammation.

Raw milk is available from local cattle ranchers.