Author: Tom Ulrich

Short telomeres, myriad diseases: The complex mystery of dyskeratosis congenita

dyskeratosis congenita
The chromosome tips known as telomeres can be compromised by many different mutations — with many different effects. (vitstudio/Shutterstock)

Genetic diseases largely fall into two overarching camps. You have simple, single-gene alterations that produce a single, recognizable disease. And you have conditions like diabetes or cardiovascular disease, where many variations in many genes all make small contributions that fuel the illness.

Dyskeratosis congenita (DC) doesn’t fit either profile. While this rare genetic condition manifests in certain predictable ways (bone marrow failure among the most common), there is huge variability between patients. Yet genetics has revealed one common thread: the molecular caps that protect the ends of chromosomes, known as telomeres, are shortened in DC patients. This results in cells that age too quickly.

From there things get complicated, because problems with any of 11 different genes can trigger short telomeres in DC. And DC, it appears, is only the beginning.

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Fever, revisited: ResearchKit app will tap crowd-sourced temperature data

Feverprints temperature

What, exactly, is a fever?

It’s a surprisingly simple but important question in medicine. While a body temperature of 98.6°F (37°C) is generally considered “normal,” this number doesn’t account for temperature differences between individuals — and even within individuals at various times of the day. While a common sign of infection, fever can also occur with other medical conditions, including autoimmune and autoinflammatory diseases.

“Many factors come together to set an individual’s ‘normal’ temperature, such as age, size, time of day and maybe even ancestry,” says Jared Hawkins, MMSc, PhD, the director of informatics for Boston Children’s Hospital’s Innovation & Digital Health Accelerator (IDHA) and a member of the hospital’s Computational Health Informatics Program. “We want to help create a better understanding of the normal temperature variations throughout the day, to learn to use fever as a tool to improve medical diagnosis, and to evaluate the effect of fever medications on symptoms and disease course.”

That’s where Feverprints comes in

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‘Hotspots’ for DNA breakage in neurons may promote brain genetic diversity, disease

DNA breakage brain
DNA breaks in certain genes may help brains evolve, but also can cause disease (Constantin Ciprian/Shutterstock)

As organs go, the brain seems to harbor an abundance of somatic mutations — genetic variants that arise after conception and affect only some of our neurons. In a recent study in Science, researchers found about 1,500 variants in each of neurons they sampled.

New research revealing the propensity of DNA to break in certain spots backs up the idea of a genetically diverse brain. Reported in Cell last month, it also suggests a new avenue for thinking about brain development, brain tumors and neurodevelopmental/psychiatric diseases.

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One-two punch: Small peptides attack ovarian cancer cells and their environment

ovarian cancer psaptides
Serous ovarian carcinoma (Nephron via Wikimedia Commons)

Ovarian cancer is the fifth leading cause of cancer death among women. Tumors often remain silent until they have spread; as a result, many women go undiagnosed until the disease has already advanced. Ovarian cancer cells often develop resistance to chemotherapy with taxanes and platinum agents, leaving few therapeutic options for women with advanced disease.

Two small peptides could present a new approach to ovarian cancer and potentially other tumors. Derived from a naturally-occurring human protein, they forced tumors to shrink significantly in an animal model of metastatic ovarian cancer, report researchers from Boston Children’s Hospital’s Vascular Biology Program, the University of Bergen and Weill Cornell Medical College in Science Translational Medicine last week.

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Science seen: Stealthy beta cell transplants for diabetes

diabetes encapsulated beta cells Daniel Anderson
Type 1 diabetes afflicts more than 300 million people worldwide. Researchers have long sought a way to replace the insulin-producing beta cells lost in the disease, but transplanted cells are susceptible to immune attack. In this image, beta cells generated from human embryonic stem cells are encapsulated in microspheres made from a material called alginate, which help cloak the cells from the immune system. However, the reddish, blue and green markers on the spheres’ surfaces indicate that immune cells have discovered spheres and their cargo, and begun to block them off from the rest of the body.

In simultaneous papers in Nature Medicine and Nature Biotechnology, Daniel Anderson, PhD — a professor of applied biology at MIT and a researcher in Boston Children’s Hospital’s Department of Anesthesia, Perioperative and Pain Medicine — and his collaborators reported on their search for effective cloaking materials They also announced that microsphere-encapsulated beta cells can reverse diabetes in a mouse model. With further work on the microspheres’ chemistry and geometry, the team hopes to improve their cloaking abilities and provide longer lasting protection for beta cells. (Image: Andrew Bader, Omid Veiseh, Arturo Vegas, Anderson/Langer Laboratory, Koch Institute at MIT)

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A long wait, but worth it: Vonvendi’s Boston origins

blood vessel von willebrand factor Vonvendi
(ktsdesign/Shutterstock)

It’s no secret that it can take years, even decades, for a biological or medical discovery to move from the laboratory to the bedside. The Pharmaceutical Researchers and Manufacturers of America estimates that it takes on average at least 10 years (and $2.6 billion) to develop a new medicine from start to market.

But some wait times stand out. Take the story of Vonvendi, a recombinant form of von Willebrand factor (vWF), a clotting protein implicated in von Willebrand disease, a bleeding disorder.

Stuart Orkin, MD, of Dana-Farber/Boston Children’s Cancer and Blood Disorders Center and his then-research fellow David Ginsburg, MD, first cloned the gene for vWF in 1985. Pharmaceutical company Baxalta, which has been developing Vonvendi based on Orkin and Ginsburg’s original discovery, won FDA approval for the drug at the end of 2015.

But what makes this story unique isn’t the 30-year lag. Rather, it’s that — for reasons that aren’t entirely clear — the patent Orkin and Ginsburg filed for vWF in 1985 hung in limbo until 2013. But today, both men agree that while the wait was long, seeing their discovery emerge as a treatment is thrilling to no end.

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Science seen: A “wheel of death” for bacteria

inflammasome innate immunity

The innate immune system acts like a border patrol for the body, picking up bacteria and other invading pathogens using molecular sensors. One key player is the inflammasome, a multi-protein complex depicted here through cryo-electron microscopy (cryo-EM). Using structural biology tools like cryo-EM and X-ray crystallography, the Wu lab in Boston Children’s Hospital’s Program in Cellular and Molecular Medicine show how protein components come together in inflammasomes to form a “wheel of death” against bacterial infection.

Once they detect an invader, inflammasomes send out signals that trigger infected cells to die using an inflammatory death pathway called pyroptosis. They also call for backup from the adaptive immune system, in the form of inflammation. (Image: Wu laboratory/Liman Zhang)

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Tracking Zika? Use HealthMap

Like a virus, the story of Zika virus in the Americas is evolving very, very rapidly. Just in the last week we’ve seen:

To help public health investigators, policy makers, epidemiologists and others keep up with the virus, the team at HealthMap has released a dedicated Zika virus tracking resource at http://www.healthmap.org/zika/. The new map brings in Zika-related information and news from a variety of sources in near real-time, and includes a constantly updated interactive timeline of the virus’s explosive spread across South and Central America.

The HealthMap team is also providing regularly updated coverage of the Zika virus outbreak on their Disease Daily blog.

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Science seen: Oral cancer up close

oral squamous cell carcinoma oral cancer lymphatic system cancer metastasis

Oral squamous cell carcinoma (OSCC), a kind of oral cancer, affects some 30,000 Americans annually. It spreads through the lymphatic system and often has already metastasized by the time it’s diagnosed. The top image here, from a recent study in the American Journal of Pathology, is a healthy mouse tongue; the bottom is the swollen tongue of a mouse with OSCC. The cancerous tongue is overloaded with lymphatic vessels, appearing in blue and white, which help the tumor spread to the regional lymph nodes. The Bielenberg lab in Boston Children’s Hospital’s Vascular Biology Program is studying ways of blocking the progression of this and other cancers by inhibiting their spread through the lymphatic system. (Image: Bielenberg laboratory/Kristin Johnson)

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Pediatric cancers and precision medicine: The feasibility question

precision cancer medicine personalized medicine pediatric oncology childhood tumors
What is precision cancer medicine all about? See the full infographic at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center.

A family walks into their oncologist’s office and sits down. Their son’s care team is there, ready to discuss the sequencing report they received about the tumor in his leg.

“We think we have something,” the oncologist says. “We found a known cancer-associated mutation in one gene in the tumor. There’s a drug that targets that exact mutation, and other children and adults whose tumors have this mutation have responded well. We’ll have to monitor your son closely, but we think this is a good option.”

This hypothetical conversation, while common in adult oncology, happens rarely (if at all) on the pediatric side. This kind of personalized, genomics-driven medicine (where the genetic alterations in a patient’s tumor drive therapy, not the tumor’s location) isn’t a standard approach for childhood cancers yet.

Note that I said yet. The door to personalized pediatric genomic cancer medicine is cracking open, in part because three recent papers — including one out of Dana-Farber/Boston Children’s Cancer and Blood Disorders Center — are starting to convince the field that clinical genomics can indeed be done in pediatric oncology.

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