Tooth sweet

A LOLLIPOP sweet that actively prevents tooth decay has hit the shops in America. It is the brainchild of Wenyuan Shi, a microbiologist at the University of California, Los Angeles.

The orange-flavoured, sugar-free lollipop that Shi and his team at the university’s school of dentistry have devised is infused with a natural ingredient found in liquorice. It kills Streptococcus mutans, which is the primary cavity-causing bacterium.

Marketed as Dr John’s Herbal Candy, the lollipop is being made by a confectionery manufacturer that licenses the technology from the university.

The lollipop is the first commercial manifestation of Shi’s attempt to apply medical approaches to dentistry, by identifying the decay-causing pathogens among the 700 kinds of bacteria living in the human mouth, tracking their presence and then targeting them with antimicrobial “smart bombs” that he and his lab can engineer to attack the decay-causing bacteria without destroying good ones.

Head-scratcher

WHY does scratching an itch bring such pleasurable relief? Dermatologists at Wake Forest University say their MRI scans of 13 volunteers reveal that scratching makes areas of our brains that are associated with unpleasant or aversive emotions and memories become significantly less active.

The report, in the Journal of Investigative Dermatology, indicates that scratching does not so much stop the itch, but alleviates our irritation at it.

Looking your age?

IF YOU go through life lying about your age, science can now find you out – thanks to the radioactive fallout from Cold War weapons testing.

Danish investigators have found that they can estimate your date of birth with a high degree of accuracy, by subjecting protein from the lens of your eye to radiocarbon dating.

The transparent proteins, called crystallins, build up in babies’ eyes from birth until around the age of 2. Once the construction is finished, the crystallins remain essentially unchanged for the rest of our lives. Thus, they provide a record of the environment we spent our first days in – including the type of radiation.

From the end of the Second World War until about 1960, the Cold War superpowers ran a series of nuclear bomb tests in the atmosphere. These detonations have affected the content of radioactive materials in the air and created what scientists refer to as the “C-14 bomb pulse”.

From the first nuclear bang until the nuclear test ban treaties were agreed, the quantity of C-14 in the atmosphere doubled. Since 1960, it has slowly decreased to natural levels.

Scientists at the universities of Copenhagen and Aarhus report in the Public Library of Science’s journal PLoS One, how the fallout got into the food chain and thus into our crystallins. These proteins therefore reflect the content of C-14 present in the atmosphere at the time of their creation, shortly after birth.

Using a large nuclear accelerator, the physicists can determine the amount of C-14 in as little as one milligram of lens tissue and calculate the year of birth. Gotcha.

Diabetic dream

SALSALATE, a drug similar to aspirin, may offer a cheap way to treat diabetes in obese young people by cutting blood glucose and inflammation in their circulatory system, says a Diabetes Care study. Harvard Medical School doctors say that it has long been known that long-term aspirin use also has these benefits, but aspirin causes bleeding in the gut. Salsalate is kinder on the tum.

Body clock watch

A NEW skin test to tell if you are a lark or an owl could help a wide range of patients, say Swiss and German scientists.

They have cultured skin cells from 28 extreme night owls and larks, in order to examine a gene that regulates the skin cells’ “slave clocks”.

The slave clocks are set by our main circadian-rhythm clock in the brain, and act as timekeeping outposts around the body. To the scientists’ surprise, the cultured cells stayed synchronised with their owner’s main clock, offering a new way to tell how a person’s circadian clock operates deep in the brain. As well as offering cheaper and more practical ways to diagnose and treat sleep disorders, the discovery, in the Proceedings of the National Academy of Sciences, may help to make many drug therapies more effective, says Achim Kramer, of the Free University of Berlin.

Many drugs, including cholesterol medicines and chemotherapy, work best if taken at specific points in the sleep/wake cycle, Achim says.

It’s a lung shot

HEALTH officials in Iowa are on the trail of a rather ironic infectious-disease outbreak. They have traced the source of the rare fungal lung disease, called histoplasmosis, to a meeting held at the state Governor’s mansion.

Now they are having to track everyone who attended it, as they may have been infected. The meeting, conducted by the American Lung Association, resulted in several ALA employees contracting the disease and undergoing treatment.

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