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Josephine Mun-Yee (Josephine) Lok, MD

Physician, Assistant in Pediatrics, Pediatric Critical Care Medicine

  • Phone: 617-724-4380
Department of Pediatrics


  • Critical Care Center
  • Pediatric Intensive Care Unit
  • MassGeneral Hospital for Children
  • Critical Care Medicine/PICU
Clinical Interests
Sepsis and Septic Shock
Brain injury
Critical care education
Boston: Massachusetts General Hospital
Medical Education
MD, Albert Einstein College of Medicine
Residency, Beth Israel Deaconess Medical Center
Residency, Tufts Medical Center
Fellowship, The Johns Hopkins Hospital
Board Certifications
Pediatric Critical Care Medicine, American Board of Pediatrics
Foreign Languages
Patient Age Group
Accepting New Patients
Accepting New Patients


My research focuses on the neurovascular responses, in particular as it relates to the pathological processes after brain trauma.  I am also interested in the actions of neuregulin-1, an endogenous growth factor, within the neurovascular unit.  NRG1 is known to be important in the function of neurons and glia, but its activity in endothelial cells is not as well defined.  My goals were to 1) determine whether NRG1 plays significant roles in the biology of brain microvascular endothelial cells; and 2) to investigate the neuroprotective potential of NRG1 in brain trauma.  Data from my experiments demonstrated that NRG1 has key functions in brain microvascular cells; in particular, NRG1 prevents endothelial hyper-permeability due to cytokine injury, a significant finding given the many pathological processes that stem from microvascular hyper-permeability during CNS and systemic illness. 

Research of Josephine Lok, MD

The microvascular endothelium is instrumental in many processes in the brain, including oxygen delivery, barrier function, and response to inflammation. After brain trauma, microvasculature disturbances lead to increased permeability, vasoconstriction, and capillary occlusion, events which amplify the primary insult. An understanding of these endothelial responses to injury is important in the investigation of neuroprotective strategies during brain injury. This topic forms one major area of my research.

Pediatric Critical Care Unit
55 Fruit Street
Boston, MA 02114-2696

Phone: 617-724-4380
Fax: 617-724-4391

Pediatric Critical Care Unit
55 Fruit Street
Boston, MA 02114-2696

Phone: 617-724-4380
Fax: 617-724-4391


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