Monthly Archives: July 2017

How Zika Virus Could Help Fight 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. [27 Devastating Infectious Diseases]

“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.

How Your Height May Raise Your Risk for Blood Clots

Your height may be linked to your risk of blood clots: A new study from Sweden found that taller men and women were more likely to develop blood clots in their veins than their shorter counterparts were.

Compared with men who were taller than 6 feet 2 inches (190 centimeters), men who were shorter than 5 feet 3 inches (160 cm) were 65 percent less likely to develop a blood clot in their veins, according to the study. And compared with women taller than 6 feet (185 cm), woman who were shorter than 5 feet 1 inch (155 cm) were 69 percent less likely to develop a venous blood clot.

Venous blood clots, or “venous thromboembolisms,” are blood clots that start in a person’s veins, according to the American Heart Association(AHA). One type of venous blood clot is called a deep vein thrombosis (DVT), and it often forms in the vein of a person’s leg. If a DVT breaks free from a person’s vein, it can travel to the individual’s lungs and get stuck, causing the second type of venous blood clot, a pulmonary embolism. These embolisms can be deadly.

Venous blood clots affect up to 600,000 Americans each year and are the third-leading type of blood vessel problem, after heart attack and stroke, the AHA says.

In the new study, published yesterday (Sept. 5) in the journal Circulation: Cardiovascular Genetics, the researchers looked at data on more than 2.5 million Swedish adult siblings who didn’t have a venous blood clot when the study began. Using the Swedish Hospital Register, a national database that includes information on hospital patients’ medical diagnoses, the researchers identified who had a blood clot during the 30- to 40-year study period.

By including siblings in the study, the researchers could account, in part, for genetic factors that may increase a person’s risk of blood clots, the study said. The researchers found that among same-sex sibling pairs, the risk of venous blood clots was significantly lower in siblings at least 2 inches (5 cm) shorter than their taller siblings.

The study didn’t look into why height was linked to risk of venous blood clots.

“It could just be that because taller individuals have longer leg veins, there is more surface area where problems can occur,” lead study author Dr. Bengt Zöller, an associate professor of internal medicine at Lund University in Sweden, said in a statement.

Gravity may also play a role in the possible link: There’s more gravitational pressure in the leg veins of taller individuals, and that can increase the risk of blood flow slowing or temporarily stopping, Zöller said.

The researchers noted that the study had several limitations. For example, the researchers didn’t account for lifestyle factors — such as smoking, diet and physical activity — that could increase a person’s risk for venous blood clots. In addition, the research was done in Swedish adults, and the results may not apply to Americans or other nationalities, the researchers said.

Zöller acknowledged that a person can’t do anything to change their height. However, he suggested that health care workers take height into consideration when looking at a person’s risk of developing venous blood clots.

‘Hearing Voices’ in Schizophrenia May Trace to Specific Brain Region

For people with schizophrenia, “hearing voices” is a common symptom that can be disturbing. But a new study from France suggests that stimulating a precise spot in such patients’ brains may ease these auditory hallucinations.

The study involved 59 patients with schizophrenia who said they heard voices that other people could not perceive. The people in the study answered questions about the nature of these voices, including whether the voices were friendly or threatening, happened frequently or only occasionally, or were “internal” (perceived as coming from inside a patient’s head) or “external” (perceived as coming from outside a patient’s head). Based on the participants’ answers, the individuals were given an “auditory hallucinations” score, with higher scores indicating more-severe hallucinations.

The researchers then used a therapy called high-frequency transcranial magnetic stimulation (TMS), which sends magnetic pulses through a person’s scalp to stimulate brain cells. The scientists targeted a specific part of the brain that is linked with people’s understanding and production of language, within an area known as the temporal lobe.

Patients were randomly assigned to receive either TMS or a “sham” treatment that was not expected to have an effect. Each group underwent two sessions of their treatment a day, for two days.

About 35 percent of patients in the TMS group showed a significant response to the therapy, compared to just 9 percent of patients in the sham group. A significant response was defined as a more than 30 percent decrease in the auditory hallucinations score.

Previous studies have suggested that TMS could treat auditory hallucinations in people with schizophrenia, but those studies were less rigorous than the current one. The new study is “the first controlled trial to show an improvement in these patients by targeting a specific area of the brain and using high-frequency TMS,” Dollfus said. (A controlled trial is one that includes a “control group,” i.e., a group that did not get the TMS treatment.)

Andreas Meyer-Lindenberg, director of the Central Institute of Mental Health in Mannheim, Germany, who was not involved in the study, said that the research builds on previous work suggesting that this brain region plays a critical role in the generation of voice hallucinations in schizophrenia. Although the percentage of people whose symptoms improved from the therapy was moderate, “TMS is a welcome addition to the therapeutic repertoire [for schizophrenia patients], especially for patients who do not respond to medication,” Meyer-Lindenberg said in a statement. (Meyer-Lindenberg is a member of the ECNP executive board.)

The study has been accepted for publication in the peer-reviewed journal Schizophrenia Bulletin.

This Man’s Bladder Stone Was Almost As Big As an Ostrich Egg

When a man in California went to the hospital because of bladder problems, doctors found a large reason for his pain: a mineral stone nearly the size of an ostrich egg, according to a new report of the case.

The 64-year-old man went to the emergency room because he had pain in his left side and trouble urinating. His doctors found an egg-shaped bladder stone that weighed a whopping 1.7 lbs. (770 grams) and measured 4.7 inches by 3.7 inches by 3 inches (12 by 9.5 by 7.5 centimeters), according to the report. (For reference, a typical ostrich eggweighs about 3 lbs., or 1,360 grams.) [Here’s a Giant List of the Strangest Medical Cases We’ve Covered]

Bladder stones are mineral masses that form in the bladder. In some cases, the stones are too small to be seen with the naked eye, but in others, the stones can be quite large, reaching an inch or more in diameter. According to Guinness World Records, the largest bladder stone was 7 inches long, 5 inches thick and 3.7 inches tall (17.9 by 12.7 by 9.5 cm), and weighed 4.2 lbs. (1.9 kg).

CT scans of the man’s adbomen also revealed another, much smaller stone in the man’s left ureter, which is the tube that carries urine from the kidneys to the bladder, according to the report, which was published today (Sept. 6) in The New England Journal of Medicine.

The doctors who treated the man noted that he’d had invasive bladder cancer more than a decade before he developed the stones. At the time, surgeons needed to remove his bladder, and they constructed what doctors call a “neobladder” out of segments of the man’s intestines. Like a regular bladder, the neobladder is connected to both the ureters and the urethra, which is the tube through which urine exits the body, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

Using part of the intestines to create a neobladder can increase a person’s risk of developing stones, the authors wrote.

The man had surgery to remove the stone from his bladder, and doctors used a laser to break up the stone in his left ureter, according to the report. The man had no problems after his surgery, though doctors are continuing to monitor him in case new stones form.