OHSU

Peta L. Grigsby / Juha P. Rasanen

 PETA L. GRIGSBY


Preterm labor is a leading cause of perinatal morbidity and mortality among neonates worldwide, which represents a significant social and healthcare burden. Intra-uterine infections are an important and potentially preventable cause of very early preterm birth. Ureaplasma species, and Mycoplasma hominis, are the microorganisms most frequently isolated from placenta with chorioamnionitis and from the respiratory tracts of preterm infants with associated neonatal sequelae (e.g., bronchopulmonary dysplasia).

Dr. Grigsby and colleagues are studying the temporal and mechanistic interactions among early biomarkers of infection in maternal and fetal compartments at defined stages of ascending uterine infection (from choriodecidual to intra-amniotic infection models), and characterizing functional aspects of treatment in utero and the consequences of fetal sequelae on neonatal morbidity and early childhood development.

Dr. Grigsby's recent collaboration with Dr. Juha Räsänen has extended these studies to include characterization of fetal cardiovascular hemodynamics and changes in regional circulations (i.e., cerebral, pulmonary and placental blood flow) in response to U. parvum infection and maternal therapy, utilizing a non-invasive approach with image-directed color and pulsed Doppler ultrasonography. Other collaborative research activities include studying placental insufficiency, intrauterine growth restriction, fetal programming and morphological and functional development of the heart and fetal circulation.

The long-term objectives of Dr. Grigsby's research are the elucidation of the inflammatory pathways that cause preterm labor and fetal sequelae, and the development of improved early diagnostic methods to identify those women that might benefit from specific therapeutic interventions, which by delaying or preventing preterm birth, would have a positive impact on fetal and neonatal health.

BIOGRAPHY

Dr. Peta Grigsby received her B.Sc (Hons) in Physiology, Pharmacology and Biochemistry from Monash University, Melbourne, Australia in 1998. She obtained her doctorate degree in fetal and neonatal physiology at Monash University in 2002. During her graduate tenure Dr. Grigsby studied various mechanisms which lead to preterm labor, specifically she focused on the role of prostaglandins in the initiation of normal and preterm labor. Dr. Grigsby's post-doctoral fellowship (2003-2006), was under the mentorship of Dr. Leslie Myatt (Department of Obstetrics and Gynecology, Division of Maternal and Fetal Medicine, University of Cincinnati, OH), where she focused on characterizing the temporal and tissue specific localization and expression of PGE2 receptor subtypes and the PGF2 receptor, in human myometrium, amnion and choriodecidua during pregnancy, at a variety of gestational ages. The regulation of these receptors by progesterone, estrogen and cytokines was also investigated using a cultured human myometrial cell line (ULTR) and a hormonally manipulated pregnant rat model. Dr. Grigsby is currently appointed as Affiliate Assistant Scientist at the Oregon Health & Science University, Oregon National Primate Research Center, Division of Reproductive Sciences.

KEY PUBLICATIONS

Waites KB, Schelonka RL, Xiao L, Grigsby PL, Novy MJ. Congenital and opportunistic infections: Ureaplasma species and Mycoplasma hominis. Semin Fetal Neonatal Med. 2009 Aug;14(4):190-9.

Choriodecidual Inflammation: A harbinger of the Preterm labor syndrome. Reproductive Sciences (2009, in press)

Grigsby PL, Sooranna SR, Adu-Amankwa B, Pitzer B, Brockman DE, Johnson MR and Myatt L (2006). Regional expression of prostaglandin E2 and F2 receptors in human myometrium, amnion and choriodecidua with advancing gestation and labor. Biol Repro; 75(2): 297-305. PMID: 16707767

Grigsby PL, Sooranna SR, Brockman DE, Johnson MR and Myatt L (2005). Localization And Expression Of Prostaglandin E2 Receptors In Human Placenta And Corresponding Fetal Membranes With Labor. Am J Obstet & Gynecol; 195(1):260-69. PMID: 16615925

Grigsby PL, Hirst JJ, Phillips DJ, Scheerlinck JP and Jenkin G (2003). Fetal responses to maternal and intra-amniotic endotoxin administration in pregnant sheep. Biol Repro; 68(5):1695-702. PMID: 12606477

To see a full listing of Dr. Grigsby's publications click here




JUHA P. RASANEN


He is actively involved in research focusing on placental insufficiency, fetal cardiovascular physiology and inflammation during pregnancy both in experimental models and in human pregnancies. Together with Dr. Grigsby, they are characterizing the fetal physiological adaptations to intra-uterine infection at intermediate and advanced stages of infection, and in response to maternal drug therapy. In national and international forums he has been invited to teach the examination of fetal cardiac anatomy and function by ultrasound. His clinical interests include ultrasound in pregnancy with special interest in fetal heart physiology and development.

BIOGRAPHY

Dr. Räsänen received his medical degree from University of Oulu in Finland. He completed residency in Obstetrics and Gynecology at the University of Oulu in 1993. His doctoral studies focused on human fetal cardiovascular physiology in pregnancies complicated by maternal diabetes or preeclampsia. During post-doctoral fellowship in Philadelphia (1994-1998), he focused on human fetal cardiac function with a special interest on pulmonary circulation and its regulation in normal pregnancies and in pregnancies with abnormal lung development. He returned to Finland in 1998 and worked mainly for the Academy of Finland as a Senior Research Fellow until 2006. Dr. Juha Räsänen is a newly appointed Associate Professor in the Department of Obstetrics and Gynecology at OHSU and Associate Scientist at ONPRC.

KEY PUBLICATIONS

Acharya G, Räsänen J, Mäkikallio K, Erkinaro T, Kavasmaa T, Haapsamo M, Mertens L and Huhta JC. Metabolic acidosis decreases fetal myocardial isovolumic velocities in a chronic sheep model of increased placental vascular resistance. Am J Physiol Heart Circ Physiol 294:H498-504, 2008.

Mäkikallio K, Räsänen J, Mäkikallio T, Vuolteenaho O and Huhta JC. Human fetal cardiovascular profile score and neonatal outcome in intrauterine growth restriction. Ultrasound Obstet Gynecol 31:48-54, 2008.

Huilaja L, Hurskainen T, Autio-Harmainen H, Hofmann SC, Sormunen R, Räsänen J, Ilves M, Franzke CW, Bruckner-Tuderman L and Tasanen K. Pemphigoid gestationis autoantigen, transmembrane collagen XVII, promotes the migration of cytotrophoblastic cells of placenta and is a structural component of fetal membranes. Matrix Biol 27:190-200, 2008.

Girsen A, Ala-Kopsala M, Makikallio K, Vuolteenaho O and Räsänen J. Fetal cardiac natriuretric peptide secretion is increased in pregnancies complicated by maternal type-1 diabetes. Acta Obstet Gynecol Scand 87:307-312, 2008.

Tahkola J, Räsänen J, Sund M, Mäkikallio K, Autio-Harmainen H and Pihlajaniemi T. Cardiac dysfunction in transgenic mouse fetuses overexpressing shortened type XIII collagen. Cell Tissue Res, 2008 (in press)

 To see a full listing of Dr. Räsänen 's publications click here