Bohuslav Dvorak
Research Assistant Professor of Pediatrics, (Section of Neonatology and Developmental Biology), & Cell Biology & Anatomy
Ph.D., Institute of Microbiology, Prague, Czech Republic
E-mail: dvorakb@peds.arizona.edu
Research in my laboratory is focused on the effects of milk-borne growth factors on normal and abnormal development of the neonatal gastrointestinal tract.
Research Interest:
Growth Factors and Normal Development of the Gastrointestinal Tract
Peptide growth factors present in breast milk of most mammalian species, such as EGF, IGF-I and IGF-II, are absent in all commercial infant formulas. These growth factors play an important role during the development and functional maturation of the gastrointestinal tract. To study the effects of milk-borne growth factors, we artificially feed neonatal rats combinations of supplemented and non-supplemented diets. This unique animal model allows us to utilize a variety of approaches to our research including peptide biochemistry, immunohistochemical analysis and molecular biology. (Supported by a Program Project Grant from the National Institute of Child Health and Human Development of the National Institutes of Health)
Growth Factors and Disease Development of the Gastrointestinal Tract
Numerous studies have shown that infants fed with breast milk appear to have some selective advantages over their formula-fed counterparts, including a lower incidence of gut related diseases and injuries. Neonatal necrotizing enterocolitis (NEC) is the most common gastrointestinal disease of premature infants with excessive morbidity and mortality. While the exact mechanism for pathogenesis is unknown, enteral feeding is nearly always a prerequisite for the development of this disease. Using an experimental animal model of NEC, we are studying the interactions between nutritional factors and the gastrointestinal immune system during NEC development. (Supported by an RO1 Grant from the NICHD of the National Institutes of Health)
Selected Publications:
Shinohara H, Williams CS, Koldovsky O, Philipps AF and Dvorak B. Transforming growth factor-alpha (TGF-a) delays gastric emptying and intestinal propulsive motility in suckling rats. Scand.J.Gastroenterology, in press, 2001.
Fellah AM, Philipps AF, Gillespie TJ, Galo JR, and Dvorak B. Degradation of insulin-like growth factors (IGF-I and IGF-II) in the small intestine of suckling rats. Regulatory Peptides, in press, 2001.
Dvorak B, McWilliam DL, Williams CS, Dominguez JA, Machen NW, McCuskey RS and Philipps AF. Artificial Formula Induces Precocious Maturation of the Small Intestine of Artificially Reared Suckling Rats. J. Pediatr. Gastroenterol. Nutr. 31:162-169, 2000.
Philipps AF, Dvorak B, Grille JG, Kling PJ and Koldovsky O. Appearance of receptor active insulin-like growth factor-I (IGF-I) in portal blood of suckling rats. J. Pediatr. Gastroenterol. Nutr. 31:128-135, 2000.
Dvorak B, Williams CS, McWilliam DL, Shinohara H, Dominguez JA, McCuskey RS, Philipps AF and Koldovsky O. Milk-borne epidermal growth factor modulates intestinal transforming growth factor-a levels in neonatal rats. Pediatric Research 47:1-7, 2000.
Philipps AF, Dvorak B, Anderson GG, Grille JG, Williams CS and Koldovsky O. Excretion of insulin-like growth factor-II (IGF-II) into bile of rats of different ages. Biology of Neonate 78(2): 106-112, 2000.
Dvorak B, Kolinska J, McWilliam DL, Williams CS, Higdon T, Zakostelecka M, and Koldovsky O. The expression of epidermal growth factor and transforming growth factor-a mRNA in the small intestine of suckling rats. Organ culture study. FEBS Letters 435:119-124, 1998.
Philipps AF, Anderson GG, Dvorak B, Williams CS, Lake M, LeBouton AV and Koldovsky O. Growth of artificially fed infant rats: Effect of supplementation with insulin-like growth factor-I. Am. J. Physiol. 272: R1532-R5139, 1997.
Dvorak B, Stephan AL, Holubec H, Williams CS, Philipps AF, and Koldovsky O. Insulin-like growth factor I (IGF-I) mRNA in the small intestine of suckling and adult rats. FEBS Letters 388:155-160,1996.
