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Dive into the research topics where Christina S. Han is active.

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Featured researches published by Christina S. Han.


Ultrasound in Obstetrics & Gynecology | 2011

Universal cervical-length screening to prevent preterm birth: a cost-effectiveness analysis.

Erika F. Werner; Christina S. Han; Christian M. Pettker; Catalin S. Buhimschi; Joshua A. Copel; Edmund F. Funai; Stephen Thung

To determine whether routine measurement of second‐trimester transvaginal cervical length by ultrasound in low‐risk singleton pregnancies is a cost‐effective strategy.


American Journal of Reproductive Immunology | 2011

Modulation of trophoblast angiogenic factor secretion by antiphospholipid antibodies is not reversed by heparin.

Tamara Y. Carroll; Melissa J. Mulla; Christina S. Han; Jan J. Brosens; Lawrence W. Chamley; Ian Giles; Charis Pericleous; Anisur Rahman; Anna K. Sfakianaki; Michael J. Paidas; Vikki M. Abrahams

Citation Carroll TY, Mulla MJ, Han CS, Brosens JJ, Chamley LW, Giles I, Pericleous C, Rahman A, Sfakianaki AK, Paidas MJ, Abrahams VM. Modulation of trophoblast angiogenic factor secretion by antiphospholipid antibodies is not reversed by heparin. Am J Reprod Immunol 2011; 66: 286–296


Biology of Reproduction | 2014

Human Fetal Membranes Generate Distinct Cytokine Profiles in Response to Bacterial Toll-Like Receptor and Nod-Like Receptor Agonists

Mai Hoang; Julie A. Potter; Stefan M. Gysler; Christina S. Han; Seth Guller; Errol R. Norwitz; Vikki M. Abrahams

ABSTRACT Bacterial infection-associated inflammation is thought to be a major cause of preterm premature rupture of membranes. Proinflammatory cytokines, such as interleukin 1B (IL1B), can weaken fetal membranes (FM) by upregulating matrix metalloproteinases and inducing apoptosis. The mechanism by which infection leads to inflammation at the maternal–fetal interface and subsequent preterm birth is thought to involve innate immune pattern recognition receptors (PRR), such as the Toll-like receptors (TLR) and Nod-like receptors (NLR), which recognize pathogen-associated molecular patterns (PAMPs). The objective of this study was to determine the cytokine profile generated by FMs in response to the bacterial TLR and NLR agonists peptidoglycan (PDG; TLR2), lipopolysaccharide (LPS; TLR4), flagellin (TLR5), CpG ODN (TLR9), iE-DAP (Nod1), and MDP (Nod2). PDG, LPS, flagellin, iE-DAP, and MDP triggered FMs to generate an inflammatory response, but the cytokine profiles were distinct for each TLR and NLR agonist, and only IL1B and RANTES were commonly upregulated in response to all five PAMPs. CpG ODN, in contrast, had a mild stimulatory effect only on MCP-1 and primarily downregulated basal FM cytokine production. IL1B secretion induced by PDG, LPS, flagellin, iE-DAP, and MDP was associated with its processing. Furthermore, FM IL1B secretion in response to TLR2, TLR4, and TLR5 activation was caspase 1-dependent, whereas Nod1 and Nod2 induced IL1B secretion independent of caspase 1. These findings demonstrate that FMs respond to different bacterial TLR and NLR PAMPs by generating distinct inflammatory cytokine profiles through distinct mechanisms that are specific to the innate immune PRR activated.


Obstetrics & Gynecology | 2014

Suture compared with staple skin closure after cesarean delivery: a randomized controlled trial.

Mackeen Ad; Adeeb Khalifeh; Jonah Fleisher; Alison Vogell; Christina S. Han; Jocelyn Sendecki; Christian M. Pettker; Benjamin E. Leiby; Jason K. Baxter; Anna K. Sfakianaki; Berghella

OBJECTIVE: To compare the incidence of wound complications between suture and staple skin closure after cesarean delivery. METHODS: This prospective, randomized clinical trial conducted at three hospitals in the United States between 2010 and 2012 included women undergoing cesarean delivery at 23 weeks of gestation or greater through a low-transverse skin incision. Women were randomized to closure of the skin incision with suture or staples after stratifying by body mass index and primary compared with repeat cesarean delivery. The primary outcome was incidence of wound complications, predefined as a composite of infection, hematoma, seroma, separation of 1 cm or longer, or readmission for wound complications. Analysis was according to the intention-to-treat principle; results were stratified by randomization group and adjusted for hospital by including it as a covariate. RESULTS: A total of 746 women were randomized, 370 to suture and 376 to staple closure. The median gestational age was 39 weeks. Fifty-eight women (7.8%) had wound complications—4.9% in the suture group and 10.6% in the staple group (adjusted odds ratio [OR] 0.43, 95% confidence interval [CI] 0.23–0.78); this was largely the result of the decreased incidence of wound separation in the respective groups (1.6% compared with 7.4%; adjusted OR 0.20, 95% CI 0.07–0.51). CONCLUSIONS: Suture closure of the skin incision at cesarean delivery is associated with a 57% decrease in wound complications compared with staple closure. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, www.clinicaltrials.gov, NCT01211600. LEVEL OF EVIDENCE: I


Obstetrics & Gynecology | 2011

Aspirin and heparin effect on basal and antiphospholipid antibody modulation of trophoblast function.

Christina S. Han; Melissa J. Mulla; Jan J. Brosens; Lawrence W. Chamley; Michael J. Paidas; Charles J. Lockwood; Vikki M. Abrahams

OBJECTIVE: Low molecular weight (LMW) heparin, with or without aspirin (acetylsalicylic acid [ASA]), is used to prevent complications in antiphospholipid syndrome in pregnancy. Our objective was to elucidate the actions of low-dose LMW heparin and ASA on basal and antiphospholipid antibody-induced modulation of trophoblast function. METHODS: The human first-trimester trophoblast cell line (HTR-8) was treated with or without antiphospholipid antibody in the presence of no medication, low-dose LMW heparin, low-dose ASA, or combination therapy. Interleukin (IL)-6, IL-8, IL-1&bgr;, growth-regulated oncogene-&agr;, vascular endothelial growth factor (VEGF), placental growth factor, soluble FMS-like tyrosine kinase-1, and soluble endoglin were measured in the supernatant. Cell migration was performed using a two-chamber assay. RESULTS: Low molecular weight heparin improved basal trophoblast migration and induced potent increases in growth-regulated oncogene-&agr; and soluble FMS-like tyrosine kinase-1. Aspirin did not affect basal function. Combined therapy promoted migration but did not reverse the LMW heparin-induced soluble FMS-like tyrosine kinase-1 effect. Antiphospholipid antibody increased IL-8, IL-1&bgr;, growth-regulated oncogene-alpha, VEGF, placental growth factor, and soluble endoglin secretion, while decreasing cell migration and IL-6 and soluble FMS-like tyrosine kinase-1 secretion. The antiphospholipid antibody-induced cytokine changes were best reversed with LMW heparin, with partial reversal of IL-8 and IL-1&bgr; upregulation. The antiphospholipid antibody-induced angiogenic changes were worsened by LMW heparin, with increased soluble FMS-like tyrosine kinase-1 secretion. The therapies did not reverse antiphospholipid antibody-induced decrease in migration. CONCLUSION: In the absence of antiphospholipid antibodies, LMW heparin induces potentially detrimental proinflammatory and antiangiogenic profile in the trophoblast. In the presence of antiphospholipid antibodies, single-agent LMW heparin may be the optimal therapy to counter trophoblast inflammation, but also induces an antiangiogenic response. These findings may explain the inability of current therapies to consistently prevent adverse outcomes. LEVEL OF EVIDENCE: II


Clinics in Perinatology | 2011

Abruption-associated prematurity

Christina S. Han; Frederick Schatz; Charles J. Lockwood

Chronic, subacute decidual hemorrhage (ie, abruptio placenta and retrochorionic hematoma formation) is an important contributor to preterm parturition. Such hemorrhage induces thrombin from decidual tissue factor, which plays a pivotal role in the development of preterm premature rupture of membranes and preterm delivery by acting through protease-activated receptors to promote the production of pro-inflammatory cytokines, and matrix-degrading metalloproteinases. Severe, acute abruption can lead to maternal and fetal mortality. Current management of abruption is individualized based on severity of disease, underlying etiology, and gestational age.


Journal of Maternal-fetal & Neonatal Medicine | 2011

Cord blood erythropoietin and interleukin-6 for prediction of intraventricular hemorrhage in the preterm neonate

Vineet Bhandari; Catalin S. Buhimschi; Christina S. Han; Sarah Y. Lee; Christian M. Pettker; Katherine Campbell; Antonette T. Dulay; Emily A. Oliver; Erika F. Werner; Irina A. Buhimschi

Objective. To evaluate cord blood erythropoietin (EPO) and interleukin-6 (IL-6) levels to predict preterm infants at risk of developing intraventricular hemorrhage (IVH). Methods. Levels of umbilical cord EPO, acid–base status and IL-6 were analyzed in 116 consecutive, preterm newborns (GA at delivery: 29 [23–34 ] weeks) born to mothers who had a clinically indicated amniocentesis to rule out infection. Early-onset neonatal sepsis (EONS) was diagnosed using symptoms, hematological criteria and blood cultures. Results. IVH was diagnosed by cranial ultrasounds. The prevalence of IVH in our population was 25% (29/116). There was a direct relationship between cord blood EPO and cord blood IL-6 concentration (r = 0.225, p = 0.014), independent of GA at birth. Elevated cord blood EPO levels (r = 0.182, p = 0.016) and GA at birth (r = −0.236, p = 0.004) remained significant independent factors associated with the risk of IVH, when evaluated with stepwise logistic regression analyses. Cord blood IL-6, pH, and EONS were not associated with IVH. These relationships remained following correction for GA at birth (p = 0.027). Conclusions. Our results suggest that elevation in cord blood EPO may predict newborns at risk for IVH, independent of fetal inflammatory status. Further studies are warranted to confirm this association.


The Journal of Clinical Endocrinology and Metabolism | 2010

Amniotic Fluid Angiopoietin-1, Angiopoietin-2, and Soluble Receptor Tunica Interna Endothelial Cell Kinase-2 Levels and Regulation in Normal Pregnancy and Intraamniotic Inflammation-Induced Preterm Birth

Catalin S. Buhimschi; Vineet Bhandari; Antonette T. Dulay; Stephen Thung; Sonya S. Abdel Razeq; Victor A. Rosenberg; Christina S. Han; Unzila Ali; Eduardo Zambrano; Guomao Zhao; Edmund F. Funai; Irina A. Buhimschi

BACKGROUND Angiopoietin-1 (Ang-1) and Ang-2 act selectively on endothelial cells by engaging the Tunica interna endothelial cell kinase-2 (Tie2) receptor. A soluble form of Tie2 (sTie2) blocks angiopoietin bioactivity. OBJECTIVE The aim of the study was to characterize changes and expression patterns of Ang-1, Ang-2, and sTie2 in amniotic fluid (AF) and placenta during human pregnancy and intraamniotic inflammation (IAI)-induced preterm birth. DESIGN AND SETTING We conducted a cross-sectional study at a tertiary university hospital. PATIENTS AF levels of Ang-1, Ang-2, and sTie2 were evaluated in 176 women during second trimester (n = 40), third trimester (n = 37), and preterm labor (positive IAI, n = 50; negative IAI, n = 49). Placenta and cord blood of select women were analyzed. MAIN OUTCOME MEASURES Ang-1, Ang-2, sTie2, and IL-6 were evaluated by ELISA. Real-time PCR measured Ang-1, Ang-2, and Tie2 placental mRNA levels. Placenta was immunostained for Ang-1 and Ang-2. Placental explant cultures were stimulated with lipopolysaccharide, Pam3Cys, and modulators of protein synthesis/secretion (cycloheximide, monensin, and brefeldin A). RESULTS In normal pregnancy, the levels and ratios of AF Ang-1, Ang-2, and sTie2 varied with gestational age (GA) (P < 0.001). PCR revealed corresponding changes in placental Ang-1 and Ang-2, but not Tie2, mRNA. IAI raised AF Ang-1, Ang-2, and sTie2 above the expected level for GA without affecting their placental mRNA. Ang-2 immunoreactivity appeared enhanced in areas of villous edema. AF Ang-2/Ang-1 ratio was an important determinant of cord blood IL-6 (P < 0.001). Ex-vivo, sTie2 release was increased by Golgi disrupting but not bacterial mimic agents. CONCLUSIONS Ang-1, Ang-2, and sTie2 are physiological constituents of AF that are GA and IAI regulated. Ang-2/Ang-1 ratio may play a role in modulating the fetal inflammatory response to IAI. Placental sTie2 shedding likely involves a Golgi-mediated mechanism.


American Journal of Obstetrics and Gynecology | 2012

Antenatal lamivudine to reduce perinatal hepatitis B transmission: a cost-effectiveness analysis.

Unzila Nayeri; Erika F. Werner; Christina S. Han; Christian M. Pettker; Edmund F. Funai; Stephen Thung

OBJECTIVES This study aimed to determine whether administration of lamivudine to pregnant women with chronic hepatitis B in the third trimester is a cost-effective strategy in preventing perinatal transmission. STUDY DESIGN We developed a decision analysis model to compare the cost-effectiveness of 2 management strategies for chronic hepatitis B in pregnancy: (1) expectant management or (2) lamivudine administration in the third trimester. We assumed that lamivudine reduced perinatal transmission by 62%. RESULTS Our Markov model demonstrated that lamivudine administration is the dominant strategy. For every 1000 infected pregnant women treated with lamivudine,


Obstetrics & Gynecology | 2008

Spontaneous ovarian hyperstimulation in a naturally conceived pregnancy with uncontrolled hypothyroidism.

Racine N. Edwards-Silva; Christina S. Han; Yen Hoang; Lee-Chuan Kao

337,000 is saved and 314 quality-adjusted life-years are gained. For every 1000 pregnancies with maternal hepatitis B, lamivudine prevents 21 cases of hepatocellular carcinoma and 5 liver transplants in the offspring. The model remained robust in sensitivity analysis. CONCLUSION Antenatal lamivudine administration to pregnant patients with hepatitis B is cost-effective, and frequently cost-saving, under a wide range of circumstances.

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Rashmi Rao

University of California

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E. Scibetta

University of California

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I. Datkhaeva

University of California

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