D. Brent Polk, MD
D. Brent Polk, MD
Professor of Pediatrics
CHL Mail Stop 71 Off Campus Los Angeles

Necrotising enterocolitis is characterised by disrupted immune regulation and diminished mucosal regulatory (FOXP3)/effector (CD4, CD8) T cell ratios Gut. 2013 Jan; 62(1):73-82. . View in PubMed

Epidermal growth factor receptor inhibits colitis-associated cancer in mice J Clin Invest. 2012 Aug; 122(8):2780-92. . View in PubMed

ErbB2 and ErbB3 regulate recovery from dextran sulfate sodium-induced colitis by promoting mouse colon epithelial cell survival Lab Invest. 2012 Mar; 92(3):437-50. . View in PubMed

Berberine promotes recovery of colitis and inhibits inflammatory responses in colonic macrophages and epithelial cells in DSS-treated mice Am J Physiol Gastrointest Liver Physiol. 2012 Mar 01; 302(5):G504-14. . View in PubMed

Berberine induces caspase-independent cell death in colon tumor cells through activation of apoptosis-inducing factor PLoS One. 2012; 7(5):e36418. . View in PubMed

Characterization of a probiotic-derived soluble protein which reveals a mechanism of preventive and treatment effects of probiotics on intestinal inflammatory diseases Gut Microbes. 2012 Jan-Feb; 3(1):25-8. . View in PubMed

Transactivation of EGFR by LPS induces COX-2 expression in enterocytes PLoS One. 2012; 7(5):e38373. . View in PubMed

Spermine oxidase mediates the gastric cancer risk associated with Helicobacter pylori CagAGastroenterology. 2011 Nov; 141(5):1696-708. e1-2. . View in PubMed

STAT6 activation in ulcerative colitis: a new target for prevention of IL-13-induced colon epithelial cell dysfunction Inflamm Bowel Dis. 2011 Nov; 17(11):2224-34. . View in PubMed

Probiotics and immune health Curr Opin Gastroenterol. 2011 Oct; 27(6):496-501. . View in PubMed

Tumor necrosis factor receptor 1-dependent depletion of mucus in immature small intestine: a potential role in neonatal necrotizing enterocolitis Am J Physiol Gastrointest Liver Physiol. 2011 Oct; 301(4):G656-66. . View in PubMed

Alanyl-glutamine promotes intestinal epithelial cell homeostasis in vitro and in a murine model of weanling undernutrition Am J Physiol Gastrointest Liver Physiol. 2011 Oct; 301(4):G612-22. . View in PubMed

TNF-a converting enzyme-mediated ErbB4 transactivation by TNF promotes colonic epithelial cell survival Am J Physiol Gastrointest Liver Physiol. 2011 Aug; 301(2):G338-46. . View in PubMed

Specific epidermal growth factor receptor autophosphorylation sites promote mouse colon epithelial cell chemotaxis and restitution Am J Physiol Gastrointest Liver Physiol. 2011 Aug; 301(2):G368-76. . View in PubMed

TNF transactivation of EGFR stimulates cytoprotective COX-2 expression in gastrointestinal epithelial cells Am J Physiol Gastrointest Liver Physiol. 2011 Aug; 301(2):G220-9. . View in PubMed

Colon-specific delivery of a probiotic-derived soluble protein ameliorates intestinal inflammation in mice through an EGFR-dependent mechanism J Clin Invest. 2011 Jun; 121(6):2242-53. . View in PubMed

KSR1 is a functional protein kinase capable of serine autophosphorylation and direct phosphorylation of MEK1 Exp Cell Res. 2011 Feb 15; 317(4):452-63. . View in PubMed

KSR1 protects from interleukin-10 deficiency-induced colitis in mice by suppressing T-lymphocyte interferon-? production. Gastroenterology. 2011 Jan; 140(1):265-74.. View in PubMed

Sprouty keeps bowel kinases regular in colon cancer, while miR-21 targets Sprouty Cancer Biol Ther. 2011 Jan 01; 11(1):122-4. . View in PubMed

ErbB4 promotes cyclooxygenase-2 expression and cell survival in colon epithelial cells Lab Invest. 2010 Oct; 90(10):1415-24. . View in PubMed

Disruption of NF-kappaB signalling by ancient microbial molecules: novel therapies of the future? Gut. 2010 Apr; 59(4):421-6.. View in PubMed

Probiotics: progress toward novel therapies for intestinal diseases Curr Opin Gastroenterol. 2010 Mar; 26(2):95-101. . View in PubMed

Endoscopic ultrasound to guide the combined medical and surgical management of pediatric perianal Crohn's disease Inflamm Bowel Dis. 2010 Mar; 16(3):461-8. . View in PubMed

Functional analysis of the p40 and p75 proteins from Lactobacillus casei BL23 J Mol Microbiol Biotechnol. 2010; 19(4):231-41. . View in PubMed

Ontogeny of FOXP3(+) regulatory T cells in the postnatal human small intestinal and large intestinal lamina propria Pediatr Dev Pathol. 2009 Nov-Dec; 12(6):443-9. . View in PubMed

Epidermal growth factor receptor activation protects gastric epithelial cells from Helicobacter pylori-induced apoptosis Gastroenterology. 2009 Apr; 136(4):1297-1307, e1-3. . View in PubMed

Helicobacter pylori regulates cellular migration and apoptosis by activation of phosphatidylinositol 3-kinase signaling J Infect Dis. 2009 Mar 01; 199(5):641-51. . View in PubMed

The ErbB4 growth factor receptor is required for colon epithelial cell survival in the presence of TNF Gastroenterology. 2009 Jan; 136(1):217-26. . View in PubMed

Low levels of tumor necrosis factor alpha increase tumor growth by inducing an endothelial phenotype of monocytes recruited to the tumor site Cancer Res. 2009 Jan 01; 69(1):338-48. . View in PubMed

Mechanisms of probiotic action: Implications for therapeutic applications in inflammatory bowel diseases Inflamm Bowel Dis. 2008 Nov; 14(11):1585-96. . View in PubMed

TNFR1 promotes tumor necrosis factor-mediated mouse colon epithelial cell survival through RAF activation of NF-kappaB J Biol Chem. 2008 Oct 24; 283(43):29485-94. . View in PubMed

Transactivation of EGF receptor and ErbB2 protects intestinal epithelial cells from TNF-induced apoptosis Proc Natl Acad Sci U S A. 2008 Aug 19; 105(33):11772-7. . View in PubMed

Tumor necrosis factor inhibits ligand-stimulated EGF receptor activation through a TNF receptor 1-dependent mechanism Am J Physiol Gastrointest Liver Physiol. 2008 Aug; 295(2):G285-93. . View in PubMed

Raf protects against colitis by promoting mouse colon epithelial cell survival through NF-kappaB Gastroenterology. 2008 Aug; 135(2):539-51. . View in PubMed

Probiotics ameliorate the hydrogen peroxide-induced epithelial barrier disruption by a PKC- and MAP kinase-dependent mechanism Am J Physiol Gastrointest Liver Physiol. 2008 Apr; 294(4):G1060-9. . View in PubMed

Epidermal growth factor stimulates Rac activation through Src and phosphatidylinositol 3-kinase to promote colonic epithelial cell migration Am J Physiol Gastrointest Liver Physiol. 2008 Jan; 294(1):G276-85. . View in PubMed

Integrin alpha1beta1 controls reactive oxygen species synthesis by negatively regulating epidermal growth factor receptor-mediated Rac activation Mol Cell Biol. 2007 May; 27(9):3313-26. . View in PubMed

Soluble proteins produced by probiotic bacteria regulate intestinal epithelial cell survival and growth Gastroenterology. 2007 Feb; 132(2):562-75. . View in PubMed

p38 kinase regulates epidermal growth factor receptor downregulation and cellular migration EMBO J. 2006 Dec 13; 25(24):5683-92. . View in PubMed

Probiotics as functional food in the treatment of diarrhea Curr Opin Clin Nutr Metab Care. 2006 Nov; 9(6):717-21. . View in PubMed

Cysteine-rich domains of muc3 intestinal mucin promote cell migration, inhibit apoptosis, and accelerate wound healing Gastroenterology. 2006 Nov; 131(5):1501-17. . View in PubMed

Bmp signaling is required for intestinal growth and morphogenesis Dev Dyn. 2006 Jun; 235(6):1563-70. . View in PubMed

The role of decay-accelerating factor as a receptor for Helicobacter pylori and a mediator of gastric inflammation J Biol Chem. 2006 May 12; 281(19):13317-23. . View in PubMed

Regulation of apoptosis during homeostasis and disease in the intestinal epithelium Inflamm Bowel Dis. 2006 May; 12(5):413-24. . View in PubMed

NODing off and Ramping up Inflamm Bowel Dis. 2005 Sep; 11(9):860-1. . View in PubMed

Kinase suppressor of Ras-1 protects intestinal epithelium from cytokine-mediated apoptosis during inflammation J Clin Invest. 2004 Nov; 114(9):1272-80. . View in PubMed

Commensal bacteria in the gut: learning who our friends are Curr Opin Gastroenterol. 2004 Nov; 20(6):565-71. . View in PubMed

Epidermal growth factor-stimulated intestinal epithelial cell migration requires Src family kinase-dependent p38 MAPK signaling J Biol Chem. 2004 Oct 22; 279(43):44513-21. . View in PubMed

Recurrent abdominal pain: symptom subtypes based on the Rome II Criteria for pediatric functional gastrointestinal disorders J Pediatr Gastroenterol Nutr. 2004 Feb; 38(2):187-91. . View in PubMed

Tumor necrosis factor regulates intestinal epithelial cell migration by receptor-dependent mechanisms Am J Physiol Cell Physiol. 2003 Apr; 284(4):C953-61. . View in PubMed

Probiotic bacterium prevents cytokine-induced apoptosis in intestinal epithelial cells J Biol Chem. 2002 Dec 27; 277(52):50959-65. . View in PubMed

Histopathology of ulcerative colitis in initial rectal biopsy in children Am J Surg Pathol. 2002 Nov; 26(11):1441-9. . View in PubMed

Research agenda for pediatric gastroenterology, hepatology and nutrition: developmental physiology and pathophysiologyReport of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition for the Children's Digestive Health and Nutrition Foundation. J Pediatr Gastroenterol Nutr. 2002; 35 Suppl 3:S242-5. . View in PubMed

Kinase suppressor of Ras determines survival of intestinal epithelial cells exposed to tumor necrosis factor Cancer Res. 2001 Dec 15; 61(24):8668-75. . View in PubMed

In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role? AJR Am J Roentgenol. 2001 Oct; 177(4):843-8.. View in PubMed

Activation of peroxisome proliferator-activated receptor gamma suppresses nuclear factor kappa B-mediated apoptosis induced by Helicobacter pylori in gastric epithelial cells J Biol Chem. 2001 Aug 17; 276(33):31059-66. . View in PubMed

Kinase suppressor of ras is necessary for tumor necrosis factor alpha activation of extracellular signal-regulated kinase/mitogen-activated protein kinase in intestinal epithelial cells Cancer Res. 2001 Feb 01; 61(3):963-9. . View in PubMed

Aminosalicylic acid inhibits IkappaB kinase alpha phosphorylation of IkappaBalpha in mouse intestinal epithelial cells J Biol Chem. 1999 Dec 17; 274(51):36631-6. . View in PubMed

Epidermal and hepatocyte growth factors stimulate chemotaxis in an intestinal epithelial cell line Am J Physiol. 1999 Dec; 277(6 Pt 1):C1149-59. . View in PubMed

Conversion of TNF alpha from antiproliferative to proliferative ligand in mouse intestinal epithelial cells by regulating mitogen-activated protein kinase Exp Cell Res. 1999 Jun 15; 249(2):349-58. . View in PubMed

Mesalamine blocks tumor necrosis factor growth inhibition and nuclear factor kappaB activation in mouse colonocytes Gastroenterology. 1999 Mar; 116(3):602-9. . View in PubMed

Epidermal and hepatocyte growth factors stimulate chemotaxis in an intestinal epithelial cell line Am J Physiol. 1999 12; 277(6):C1149-59. . View in PubMed

Hypertrophied pyloric mucosa in patients with hypertrophic pyloric stenosis Pediatr Radiol. 1998 Nov; 28(11):901. . View in PubMed

Epidermal growth factor receptor-stimulated intestinal epithelial cell migration requires phospholipase C activity Gastroenterology. 1998 Mar; 114(3):493-502. . View in PubMed

Tumor necrosis factor alpha regulates proliferation in a mouse intestinal cell line Gastroenterology. 1997 Apr; 112(4):1231-40. . View in PubMed

Recurrent necrotizing jejunitis in a child J Pediatr. 1996 Feb; 128(2):246-9. . View in PubMed

Shc is a substrate of the rat intestinal epidermal growth factor receptor tyrosine kinase Gastroenterology. 1995 Dec; 109(6):1845-51. . View in PubMed

Impaired human responses to tetanus toxoid in vitamin A-deficient SCID mice reconstituted with human peripheral blood lymphocytes Infect Immun. 1995 Aug; 63(8):2867-72. . View in PubMed

The antral nipple sign of pyloric mucosal prolapse: endoscopic correlation of a new sonographic observation in patients with pyloric stenosis J Ultrasound Med. 1995 Apr; 14(4):283-7. . View in PubMed

Cell density-dependent regulation of PLC gamma 1 tyrosine phosphorylation and catalytic activity in an intestinal cell line (IEC-6) J Cell Physiol. 1995 Mar; 162(3):427-33. . View in PubMed

Ontogenic regulation of phospholipase C-gamma 1 activity and expression in the rat small intestine Gastroenterology. 1994 Jul; 107(1):109-16. . View in PubMed

Intestinal Na+/H+ exchanger activity is up-regulated by bowel resection in the weanling rat Pediatr Res. 1993 Mar; 33(3):215-20. . View in PubMed

Improved growth and disease activity after intermittent administration of a defined formula diet in children with Crohn's disease JPEN J Parenter Enteral Nutr. 1992 Nov-Dec; 16(6):499-504. . View in PubMed

Bacterial meningitis presenting with normal cerebrospinal fluid Pediatr Infect Dis J. 1987 Nov; 6(11):1040-2. . View in PubMed

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