School Notes: School of Medicine
March/April 2007

Immunobiology gains department status

The Section of Immunobiology has become a full department at the medical school. Founded in 1988 and now chaired by Richard A. Flavell, the immunobiology section was one of the first university departments in the country devoted specifically to the study of the immune system. The 2005 Faculty Scholarly Productivity Index ranked Yale's immunology program as best in the United States, based on such data as faculty publications, grants, and honors and awards.

The new immunobiology department boasts 13 primary faculty members, including four investigators of the Howard Hughes Medical Institute, two members of the National Academy of Sciences, and two members of the Royal Society -- all widely recognized for their research in such areas as lymphocyte development and activation. Within the department, the newly formed Human Translational Immunology Group will concentrate on translational and clinical studies that link the department's strength in basic immunology to the clinical departments of the medical school. In this research, investigators will apply the principles of basic immunology to diseases such as arthritis, asthma, diabetes, and disorders of the vascular system.

Yale opens PET Center

The Yale Positron Emission Tomography (PET) Research Center for molecular imaging, the result of an alliance between the university and Pfizer Inc., was officially opened in January.

PET, a non-invasive diagnostic scanning technique, provides researchers and clinicians with visual images of organ function and can detect biochemical changes in body tissues before disease causes structural damage. Through its high-resolution imaging and quantitative analysis, the PET Center provides researchers with a more rapid and accurate way to determine whether a drug is reaching its target. This will enable researchers to make earlier decisions on whether to embark on a large clinical trial or abandon a drug candidate before investing large amounts of money.

The Yale PET Center is one of the few PET laboratories in the United States that is cGMP (current good manufacturing practice) compliant, meeting the highest safety standards for human subjects and quality control. The center also boasts one of the few PET scanners in the world dedicated to imaging the human brain that achieves a resolution of 2.5 millimeters.

Pfizer chairman and CEO Jeffrey B. Kindler praised the alliance between Pfizer and Yale: "This venture illustrates how great things can happen when a science-based company like Pfizer and a leading academic medical center like Yale combine resources. . . . I am confident that this collaboration will yield important research insights and, ultimately, new treatments for patients."

Molecule found to play a role in brain malformation

The absence of the molecule MEKK4 in the fetal brain may cause periventricular heterotopia (PVH), a congenital brain malformation often linked to neurological disorders such as epilepsy, mental retardation, and learning or memory deficits. The finding was reported in the journal Neuron in December by Pasko Rakic, professor and chair of neurobiology, and colleagues.

Neurons are the basic building blocks of the nervous system, specialized to transmit information throughout the body. They develop during gestation near the lining of fluid-filled ventricles and migrate to the cerebral cortex where they establish connections with other neurons.

MEKK4 regulates the gene Filamin-A, which produces a protein that organizes another protein, actin, which is essential for neuronal migration in the developing brain. Too much Filamin-A inhibits the neuronal migration. Said Rakic, "We show that MEKK4 deficiency leads to both a breakdown in the lining of the fetal ventricles and abnormally high levels of Filamin-A within the proliferative areas." The findings provide insight into the development of human PVH.