Science seen: Mapping touch perception in cerebral palsy

sensory brain mapping in cerebral palsy

Cerebral palsy (CP) is the most common motor disability of childhood. The brain injury causing CP disrupts touch perception, a key component of motor function. In this brain image from a child with CP (click to enlarge), the blue lines show nerve fibers going to the sensory cortex. The colored cubes at the top represent the parts of the sensory cortex receiving touch signals from the thumb (red cube), middle finger (blue) and little finger (green). An injury in the right side of the brain (dark area) has reduced the number of nerve fibers on that side, reducing touch sensation in the left hand and resulting in weakness.

Christos Papadelis, PhD, of Boston Children’s Hospital’s Division of Newborn Medicine hopes to use such sensory mapping information to develop better rehabilitation therapies. P. Ellen Grant, MD, director of the Fetal-Neonatal Neuroimaging and Developmental Science Center, Brian Snyder, MD, of the Cerebral Palsy Program and research assistant Madelyn Rubenstein are part of the team.

 

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CDKL5: Understanding rare epilepsies, patient by patient, neuron by neuron

CDKL5 epilepsy
Haley with her parents and neurologist Heather Olson (right)

Nine-year-old Haley Hilt has had intractable seizures all her life. Though she cannot speak, she communicates volumes with her eyes. Using a tablet she controls with her gaze, she can tell her parents when her head hurts and has shown that she knows her letters, numbers and shapes.

Haley is one of a growing group of children who are advancing the science around CDKL5 epilepsy, Haley’s newly recognized genetic disorder. When Boston Children’s Hospital geneticist Joan Stoler, MD, diagnosed Haley in 2009, there were perhaps 100 cases known in the world; today, there are estimated to be a few thousand. Haley’s neurologist, Heather Olson, MD, leads a CDKL5 Center of Excellence at the hospital that is bringing the condition into better view.

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Deconstructed ‘death receptors’ suggest new ways to tackle cancer, autoimmune disease

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The 3-D structure of the Fas death receptor’s transmembrane region, consisting of three tightly packed helices shown here from three angles. Cancer-causing mutations deform this structure, preventing “time to die” signals from passing through. (Fu Q; et al. Molecular Cell, Feb. 5, 2016).

Programmed cell death, or apoptosis, helps keep us healthy by ensuring that excess or potentially dangerous cells self-destruct. One way cells know it’s time to die is through signals received by so-called death receptors that stud cells’ surfaces. When these signals go awry, the result can be cancer (uncontrolled cell growth) or autoimmune disease (cells self-destructing too readily).

Researchers at Harvard Medical School (HMS) and the Program in Cellular and Molecular Medicine at Boston Children’s Hospital deconstructed a death receptor called Fas to learn more about its workings, using nuclear magnetic resonance (NMR) spectroscopy to reveal its structure.

They found that for immune cells to hear the “time to die” signal, a portion of Fas called the transmembrane region must coil into an intricate three-part formation, allowing the signal to pass into the cell. The NMR imaging also revealed that the amino acid proline is critical for the formation’s stability. Cancer-causing mutations in the transmembrane region (one of them affecting proline itself) deformed this delicate structure and prevented signals from passing through.

This better understanding of the Fas death receptor, published last week in Molecular Cell, could lead to new approaches that bypass Fas to encourage apoptosis in cancer or, conversely, inhibit Fas in autoimmune disease.

Read more on HMS’s news site.

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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 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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3-D printed hearts of hope

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Jason Ayres with son Patrick, Dr. Emani, and Patrick’s 3-D printed heart

Jason Ayres, a family doctor in Alabama, was speechless as he held his adopted son Patrick’s heart in his hands. Well, a replica of his son’s heart — an exact replica, 3-D printed before the 3-year-old boy had lifesaving open-heart surgery.

Patrick was one of the first beneficiaries of 3-D printing technology at Boston Children’s Hospital, which last year helped open a new frontier in pediatric cardiac surgery. Patrick was born with numerous cardiac problems; in addition to double outlet right ventricle and a complete atrioventricular canal defect, his heart lay backwards in his chest.

“We knew early on that he’d need complex surgery to survive,” says Jason.

Finely detailed models of Patrick’s heart created by the Simulator Program at Boston Children’s gave surgeon Sitaram Emani, MD, at the Boston Children’s Heart Center an up-close-and-personal look at his complex cardiac anatomy.

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Pediatric cancers and precision medicine: The feasibility question

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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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The cell that caused melanoma: Cancer’s surprise origins, caught in action

It’s long been a mystery why some of our cells can have mutations associated with cancer, yet are not truly cancerous. Now researchers have, for the first time, watched a cancer spread from a single cell in a live animal, and found a critical step that turns a merely cancer-prone cell into a malignant one.

Their work, published today in Science, offers up a new set of therapeutic targets and could even help revive a theory first floated in the 1950s known as “field cancerization.”

“We found that the beginning of cancer occurs after activation of an oncogene or loss of a tumor suppressor, and involves a change that takes a single cell back to a stem cell state,” says Charles Kaufman, MD, PhD, a postdoctoral fellow in the Zon Laboratory at Boston Children’s Hospital and the paper’s first author.

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Genetic analysis backs a neuroimmune view of schizophrenia: Complement gone amok

C4 (in green) located at the synapses of human neurons. (Courtesy Heather de Rivera, McCarroll lab)
C4 (in green) located at the synapses of human neurons. (Courtesy Heather de Rivera, McCarroll lab)

A deep genetic analysis, involving nearly 65,000 people, finds a surprising risk factor for schizophrenia: variation in an immune molecule best known for its role in containing infection, known as complement component 4 or C4.

The findings, published this week in Nature, also support the emerging idea that schizophrenia is a disease of synaptic pruning, and could lead to much-needed new approaches to this elusive, devastating illness.

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Microptosis: Programmed death for microbes?

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Trypanosoma parasites in a blood smear. (CDC)

Of the various ways for a cell to die — necrosis, autophagy, etc. — apoptosis is probably the most orderly and contained. Also called programmed cell death (or, colloquially, “cellular suicide”), apoptosis is an effective way for diseased or damaged cells to remove themselves from a population before they can cause problems such as tumor formation.

“Apoptosis has special features,” says Judy Lieberman, MD, PhD, an investigator in Boston Children’s Hospital’s Program in Cellular and Molecular Medicine. “It’s not inflammatory, and it activates death pathways within the cell itself.”

Conventional wisdom holds that apoptosis is exclusive to multicellular organisms. Lieberman disagrees. She thinks that microbial cells — such as those of bacteria and parasites — can die in apoptotic fashion as well. In a recent Nature Medicine paper, she and her team make the case for the existence of what they’ve dubbed “microptosis.” And they think it could be harnessed to treat parasitic and other infections.

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