Monthly Archives: April 2017

Magnetic Fields Can Remotely Control Cells in Mice

Using magnetic fields, scientists can activate specific brain cells in mice and make them run, spin and freeze, new research shows.

This could help scientists pinpoint the specific brain circuits animals use for certain behaviors, which could in turn help scientists pinpoint with greater accuracy which brain areas are involved in those same behaviors in humans, said Arnd Pralle, a biophysicist at the University at Buffalo in New York.

The main goal is to develop tools that can help scientists study the brains of laboratory animals to see how they encode emotions and behaviors, Pralle told Live Science. “We can translate a lot of that to human brains,” he added. [Top 10 Mysteries of the Mind]

Scientists have used implanted electrodes to control the movement and thoughts of monkeys, while others have genetically engineered brain circuits that turn on with a beam of laser light. Brain implants have even allowed one monkey to control the movements of another, a 2014 experiment found. However, those methods involve either implanting electrodes into the brain or hard-wiring a bulky cable into the brain. But those procedures can do damage to the animals, and essentially keeps them tethered to a cable all the time, Pralle said.

Transcranial magnetic stimulation, meanwhile, is FDA-approved to treat depression that does not respond to medication, but it acts on a wide area of the brain and is not targeted to specific networks. Scientists, however, still don’t fully understand why it works, Pralle said.

In the current study, Pralle and his colleagues used magnetic fields to turn on individual brain cells. Ordinarily, magnetic fields pass through biological tissue without affecting it, so the team needed a way to translate the magnetic stimulation into heat energy. To accomplish this task, they injected tiny magnetic nanoparticles that translated oscillating magnetic fields into heat energy. These nanoparticles then latch onto the surface of brain cells. When the cells heat up, temperature-sensitive channels on the neurons opened, flooding the channels with positive ions (charged particles) and causing the neurons to fire. (Normally, mice have very few heat-sensitive channels in their brains, so the team genetically engineered the mice to carry these channels.)

Using this technique, the team manipulated the mice’s specific movements, causing them to spin around, run, and even freeze and lose control of their extremities.

The new technique has advantages over other methods for manipulating brain function in animals, Pralle said. For instance, the magnetic field they use operates over a larger region of the brain, meaning they could target separate brain regions at the same time, he said. In primates, multiple brain regions must often be activated to perform specific tasks, he added.

The technique, with its use of genetic engineering and nanoparticles, is not intended to be used in human brains, and certainly not to manipulate or conduct mind-control on humans, Pralle said. Instead, inducing certain behaviors in animals is a way to pinpoint the brain regions responsible for these tasks, he said.

One day, the understanding of brain function gleaned from these animals could pinpoint the brain circuits needed to treat conditions such as Parkinson’s in humans, Pralle said.

“We might use different methods to stimulate the brain,” Pralle said. “But knowing which circuit does what, you don’t have to go dig around.”

Lead Poisoning Caused by ‘Homeopathic Magnetic’ Bracelet

An infant girl in Connecticut developed lead poisoning after wearing — and chewing on — a bracelet made with lead beads, according to a new report of the child’s case.

Doctors discovered that the 9-month-old had abnormally high bloodlead levels during a routine checkup. Her blood lead level was 41 micrograms per deciliter (ug/dL); anything over 5 ug/dL is considered abnormal, according to the report, published today (Aug. 31) by the Centers for Disease Control and Prevention (CDC).

Health investigators visited the infant’s home, and found two windows with peeling lead-based paint. However, the infant wouldn’t have been able to reach these areas, according to the report. In addition, the girl’s three siblings, who were between ages 3 and 5, had blood lead levels of less than 3 ug/dL, suggesting that the peeling paint wasn’t the source of the lead poisoning. [9 Weird Ways Kids Can Get Hurt]

Instead, investigators focused on a handmade bracelet the parents had given the infant. The bracelet was a “homeopathic magnetic hematite healing bracelet” that the parents purchased from an artisan at a local fair. The parents had given the infant the bracelet for “teething-related discomfort,” the report said. Sometimes the infant chewed on the bracelet, the report added. (Despite a lack of scientific evidence, some people purport that magnets have healing properties if placed close to the body.)

When investigators tested the beads on the bracelet, they found that some of the beads had extremely high levels of lead: 17,000 parts per million (ppm). The amount of lead that’s considered safe for children’s products is 90 ppm or 100 ppm, depending on the type of product, according to the U.S. Consumer Product Safety Commission (CPSC).

In general, the most common way children get lead poisoning is by ingesting something that contains lead. In 2003 and 2006, for example, there were several cases of severe lead poisoning and death linked to lead-containing jewelry and charms marketed to children, the report said. After these instances, the CPSC set limits on the amount of lead allowed in products marketed to kids, and each year, there are recalls of children’s jewelry that exceed those limits. However, the limits do not apply to products that aren’t intended for use by children, the report noted.

Investigators were unable to track down the manufacturer of the beads or the bracelet maker, according to the report.

There’s no safe amount of lead exposure for children, according to theCDC, and the toxic heavy metal can affect nearly every part of the body. In many cases, lead exposure can occur with no obvious symptoms. Symptoms of severe lead poisoning can include confusion, seizures, coma and death.

This is not the first time that homeopathic teething products have been found to put children at risk. In October 2016, the U.S. Food and Drug Administration announced an investigation into homeopathic teething products that were linked to reports of seizures in infants and children. The products in that instance weren’t being investigated for lead levels, however; instead, the FDA was concerned that the products contained purportedly “natural” substances that weren’t regulated by the agency.

Homeopathy is an alternative medicine practice based on the idea that “like cures like.” In homeopathy, extremely minute concentrations of toxic substances are used in the idea that they could cure the symptoms that they would cause at higher doses.

Stages of Pregnancy

For a pregnant woman, feeling a new life developing inside her body is an amazing experience, even though she may not always feel her best at some points along the way.

Pregnancy can be different from woman to woman, and even for the same mother from one pregnancy to the next. Some symptoms of pregnancy last for several weeks or months, while other discomforts are temporary or don’t affect all women.

“Pregnancy is a long, 10-month journey,” said Dr. Draion Burch, an obstetrician and gynecologist at Magee-Womens Hospital at the University of Pittsburgh Medical Center.

A normal pregnancy usually lasts about 40 weeks, counting from the first day of a woman’s last menstrual period, which is about two weeks before conception actually occurs.

Pregnancy is divided into three trimesters. Each of these periods lasts between 12 and 13 weeks.

During each trimester, changes take place in a pregnant woman’s body as well as in the developing fetus, and a summary of these changes will be described below.

About two weeks after a woman has her period, she ovulates and her ovaries release one mature egg. The egg can be fertilized for 12 to 24 hours after it’s released as it travels down the fallopian tube toward the uterus.

If an egg meets up with a sperm cell that has made its way into the fallopian tube, it combines into one cell, a process that’s known as fertilization or conception.

At fertilization, the sex of the fetus is already determined, depending on whether the egg receives an X or Y chromosome from a sperm cell. If the egg receives an X chromosome, the baby will be a girl; a Y chromosome means the baby will be a boy.

According to the Cleveland Clinic, it takes about three to four days for the fertilized egg (or embryo) to move to the lining of the uterus, where it attaches or implants to the uterine wall. Once the embryo is implanted, the cells start to grow, eventually becoming the fetus and the placenta, which is tissue that can transport oxygen, nutrients and hormones from the mother’s blood to the developing fetus throughout pregnancy.

A woman will experience a lot of symptoms during her first trimester as she adjusts to the hormonal changes of pregnancy. In the early weeks, the pregnancy may not be showing much on the outside of her body, but inside many changes are taking place.

For example, human chorionic gonadotrophin (hCG) is a hormone that will be present in a woman’s blood from the time conception occurs. Levels of hCG can be detected in a woman’s urine about a week after she has a missed period, and it is why a woman will have a positive result ona home pregnancy test.

Other hormonal changes can contribute to pregnancy symptoms: Rising levels of estrogen and hCG may be responsible for the waves of nausea and vomiting known as morning sickness that a woman typically feels during her first few months of pregnancy. Despite its name, morning sickness can occur any time of day.

A woman will also feel more tired than usual during the first trimester, a symptom that’s linked with rising levels of the hormone progesterone, which increases sleepiness. She may also need to urinate more frequently as her uterus grows and presses on her bladder.

Early in pregnancy, a woman’s breasts will feel more tender and swollen, another side effect of rising levels of pregnancy hormones. Her areolas, the skin around each nipple, will darken and enlarge.

A pregnant woman’s digestive system may slow down to increase the absorption of beneficial nutrients. But reduced mobility of the digestive system might also trigger such common complaints as heartburn, constipation, bloating and gas, according to the Office on Women’s Health (OWH).

Many parts of the body will work harder during pregnancy, including a woman’s heart. Her heartbeat will increase to pump more blood to the uterus, which will supply it to the fetus.

As more blood circulates to a woman’s face, it will give her skin a rosier complexion, described as a “pregnancy glow.”

Besides the physical changes in a woman’s body, she may also experience emotional highs and lows in the early months of her pregnancy and throughout it. These emotions may range from weepiness, mood swings and forgetfulness to fear, anxiety and excitement.

A developing baby is called an embryo from the moment conception takes place until the eighth week of pregnancy.

During the first month of pregnancy the heart and lungs begin to develop, and the arms, legs, brain, spinal cord and nerves begin to form, according to the American College of Obstetricians and Gynecologists (ACOG).

The embryo will be about the size of a pea around one month into a pregnancy, Burch said. Around the second month of pregnancy, the embryo has grown to the size of a kidney bean, he explained. In addition, the ankles, wrists, fingers and eyelids form, bones appear, and the genitals and inner ear begin to develop.

After the eighth week of pregnancy and until birth occurs, a developing baby is called a fetus.

By the end of the second month, eight to 10 of the fetus’ main organs will have formed, Burch said. At this stage of pregnancy, he stressed, it’s extremely important that pregnant women do not take harmful medications, such as illegal drugs. The first trimester is also the period when most miscarriages and birth defects occur.

During the third month of pregnancy, bones and muscles begin to grow, buds for future teeth appear, and fingers and toes grow. The intestines begin to form and the skin is almost transparent.

By the second trimester, some of the unpleasant effects of early pregnancy may lessen or disappear as a woman’s body adjusts to its changing hormone levels. Sleeping may get easier and energy levels may increase.

Nausea and vomiting usually get better and go away, Burch told Live Science. But other symptoms may crop up as the fetus continues its growth and development.

Women feel more pelvic pressure, Burch said, adding that the pelvis feels heavy like something is weighing it down.

A more visible baby bump appears as the uterus grows beyond a woman’s pelvis, and the skin on her expanding belly may itch as its stretches, according to the OWH.

As the fetus is getting bigger and a woman is gaining more pregnancy weight in the front of her body, she may also experience more back pain, Burch said.

Sometime between the 16th and 18th weeks of pregnancy, a first-time mother may feel the first fluttering movements of the fetus, known as quickening, Burch said. If a woman has had a baby before, she is likely to feel the fetus kicking, squirming or turning even sooner because she knows what to expect, he explained.

The 20th week usually marks the halfway point of a woman’s pregnancy.

Burch encourages his patients to take a “baby-moon” — a mini-vacation or weekend getaway — during the second trimester, and he said the best time to get away is around the 28th week of pregnancy. A woman is generally feeling pretty good at this point, there’s a lower risk of miscarriage and premature labor, and some health professionals may discourage airplane travel after the 36th week.

In the second trimester, the fetus is growing a lot and will be between 3 and 5 inches long, Burch said. Sometime between 18 and 22 weeks, anultrasound may reveal the sex of the baby, if parents want to know this information in advance.

By the fourth month of pregnancy, eyebrows, eyelashes, fingernails and the neck all form, and the skin has a wrinkled appearance. In addition, during the fourth month the arms and legs can bend, the kidneys start working and can produce urine, and the fetus can swallow and hear, according to ACOG.

In the fifth month of pregnancy, the fetus is more active and a woman may be able to feel its movements. The fetus also sleeps and wakes on regular cycles. A fine hair (called lanugo) and a waxy coating (called vernix) cover and protect the thin fetal skin.

By the sixth month of pregnancy, hair begins to grow, the eyes begin to open and the brain is rapidly developing. Although the lungs are completely formed, they don’t yet function.

During the third trimester, as a woman’s enlarged uterus pushes against her diaphragm, a major muscle involved in breathing, she may feel short of breath because the lungs have less room to expand, according to Johns Hopkins Medicine. Her ankles, hands, feet and face may swell as she retains more fluids and her blood circulation slows.

A mother-to-be will need to pee more frequently because more pressure will be placed on her bladder. She may also have more backaches and more pain in the hips and pelvis, as these joints relax in preparation for delivery.

Her face may develop dark patches of skin, and stretch marks may appear on her belly, thighs, breasts and backside. She may also notice varicose veins on her legs.

In the third trimester, a woman’s breasts may experience some leakage of colostrum, a yellow liquid, as they get ready for breastfeeding, according to the OWH. The baby will drop lower in her abdomen.

False labor, known as Braxton-Hicks contractions, may begin to occur as a woman gets closer to her due date. A “nesting instinct” may kick in as a mother-to-be and her partner baby-proof their home, shop for baby items, prepare the nursery and await their new arrival.

During the final weeks of pregnancy, it will become harder to find a comfortable sleeping position, so women may be extremely tired, Burch said.

As delivery approaches, some women love the experience of being pregnant, while others may feel like they can’t wait for it to end, Burch said.

By the seventh month of pregnancy, the fetus kicks and stretches, and can even respond to light and sound, like music, Burch said. Eyes can open and close.

During the eighth month of pregnancy, the fetus gains weight very quickly. Bones harden, but the skull remains soft and flexible to make delivery easier. Different regions of the brain are forming, and the fetus is able to hiccup, according to ACOG.

The ninth month is the home stretch of pregnancy, and the fetus is getting ready for birth by turning into a head-down position in a woman’s pelvis. The lungs are now fully mature to prepare for functioning on their own. The fetus continues to gain weight rapidly.

The new definition of a full-term pregnancy is when a baby is born after 39 to 40 weeks (it used to be 37 weeks), Burch said.

How Zika Virus Can Help Combat Brain Cancer

The Zika virus can be a serious health threat, especially to unborn children, but now researchers say the virus itself could help treat another devastating illness — brain cancer.

A new study suggests that the same properties that make Zika a dangerous virus for unborn children could be useful in treating brain cancer in adults. The study was done in lab dishes and animals, and much more research is needed before it could be tested in humans.

It’s thought that the Zika virus naturally targets and kills brain stem cells, which are abundant in fetal brains during development. As a consequence, women infected with Zika virus during pregnancy are at increased risk of giving birth to children with neurological problems. But adults have fewer active stem cells in their brains, and as a result, the effect of Zika on adult brains is usually much less severe, the researchers said.

What’s more, the growth of certain brain cancers — including often-lethal glioblastomas — may be driven by cancer stem cells that divide and give rise to other tumor cells. These glioblastoma stem cells are typically resistant to therapies such as chemotherapy and radiation, and may fuel the return of the cancer after treatment. The researchers hypothesized that the Zika virus could target these cancer stem cells. [5 Facts About Brain Cancer]

“We wondered whether nature could provide a weapon to target the cells most likely responsible” for the return of glioblastoma after treatment, study co-author Milan Chheda of Washington University School of Medicine in St. Louis, said in a statement.

The researchers found that the Zika virus preferentially targeted and killed human glioblastoma stem cells in a lab dish, without having much of an effect on normal adult brain cells.

Next, the researchers tested the Zika therapy on mice with glioblastomas. To do this, they injected a mouse-adapted strain of Zika virus into the glioblastoma tumors. (The strain of Zika virus that infects humans does not infect mice.)

They found that mice treated with Zika showed slower tumor growth and lived longer than those that didn’t get the Zika treatment. All of the untreated mice died after about a month, but close to half of the treated mice were still alive after two months, the researchers said.

Still, much more research is needed to show that the therapy is safe and effective in humans. The researchers plan to genetically modify the Zika virus so that it is weaker and would not be expected to cause disease. A preliminary test of such an “attenuated” Zika strain showed that this virus was still capable of targeting and killing glioblastoma stem cells in a lab dish.

“Our study is a first step towards the development of safe and effective strains of Zika virus that could become important tools in neuro-oncology and the treatment of glioblastoma,” said study co-author Michael Diamond, also of Washington University.

But concerns over the safety of a Zika-based therapy will need to be addressed with further studies in animals before the therapy is tested in humans, Diamond said. Ultimately, the Zika therapy might be used along with other traditional brain cancer therapies to treat glioblastomas, the researchers said.

The new study is published today (Sept. 5) in The Journal of Experimental Medicine.

Zika is not the only virus being considered as a potential treatment for glioblastomas. Other research groups are testing measles, polio and herpes viruses as possible ways to target glioblastomas.