Abstract:
OBJECTIVE:Our purpose was to determine the effect of perfusate flow or viscosity on release and action of nitric oxide in the human fetal-placental vasculature in vitro. STUDY DESIGN:Cotyledons from normal term placentas were perfused with Hanks' buffered saline solution gassed with 95% oxygen and 5% carbon dioxide, pH 7.4, at 37 degrees C with a maternal flow rate of 10 ml/min. Fetal flow rate was varied from 1 to 10 ml/min at 10-minute intervals (n = 6), and perfusion pressure was recorded. Viscosity was varied by perfusion of both circulations with Hanks' balanced salt solution containing 0, 2.5, 5.0, 7.5, or 10% dextran, the concentration being changed every 20 minutes and pressure recorded at fetal flow rates of 4 (n = 4) or 1 ml/min (n = 7). All experiments were performed in the presence or absence of the nitric oxide synthase inhibitor N-nitro-L-arginine (10(-3) mol/L) in the same placentas. Data were analyzed by analysis of variance with repeated measures. RESULTS:Increasing fetal flow rate with or without N-nitro-L-arginine resulted in a significant increase in perfusion pressure (p = 0.0011). Addition of N-nitro-L-arginine gave an overall significant increase in perfusion pressure (p = 0.0048). At a fetal flow rate of 4 ml/min increasing dextran concentration with or without N-nitro-L-arginine gave a significant increase in perfusion pressure (p = 0.0011), but the increase in perfusion pressure in the presence of N-nitro-L-arginine did not reach significance (p = 0.06). At 1 ml/min increasing dextran concentration resulted in a significant increase in fetal perfusion pressure (p = 0.001), but no significant effect of N-nitro-L-arginine was observed. CONCLUSION:Altering shear stress by increasing fetal flow rate or viscosity of the medium may increase synthesis and release of nitric oxide, which attenuates increases in perfusion pressure.
journal_name
Am J Obstet Gynecoljournal_title
American journal of obstetrics and gynecologyauthors
Wieczorek KM,Brewer AS,Myatt Ldoi
10.1016/0002-9378(95)90327-5subject
Has Abstractpub_date
1995-09-01 00:00:00pages
708-13issue
3 Pt 1eissn
0002-9378issn
1097-6868pii
0002-9378(95)90327-5journal_volume
173pub_type
杂志文章abstract:OBJECTIVE:This study was undertaken to characterize variations in the management for women with preterm premature rupture of membranes (PPROM) among maternal-fetal medicine (MFM) specialists in the context of current recommendations for clinical practice and evidenced-based practice. STUDY DESIGN:We performed a Web-ba...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2004.08.005
更新日期:2004-10-01 00:00:00
abstract::Cardiac function was cross-sectionally studied by means of M-mode and Doppler echocardiography in 40 fetuses of mothers with well-controlled insulin-dependent diabetes at 20 to 38 weeks of gestation. These variables were measured: interventricular septal thickness, ratio between the peak velocities during early passiv...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(91)90526-w
更新日期:1991-03-01 00:00:00
abstract::We studied differences in the role of genetic factors in prematurity and intrauterine growth retardation with the use of data on 312 Amish singleton live children ascertained from Amish records in Lancaster county, Pennsylvania, between 1969 and 1980. Birth and death certificates were obtained on all children, and inb...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(87)80181-3
更新日期:1987-08-01 00:00:00
abstract::To determine the effects of suppressing fetal and maternal adrenal activity on parturition, we treated pregnant rhesus macaques with dexamethasone (0.25 to 4.0 mg, twice a day) from gestation day 130 until delivery (term = 167 days). Long-term dexamethasone treatment increased gestation length: 71% of fetuses were bor...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(83)90841-4
更新日期:1983-04-15 00:00:00
abstract::Sixty percent of neonates with Down syndrome have hypoplasia of the middle phalanx of the fifth digit. We demonstrate this finding sonographically between 17 and 20 weeks' gestation in four of five fetuses with Down syndrome. The appearance of this abnormal phalanx as well as the abnormal curvature of the fifth digit ...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(88)90517-0
更新日期:1988-07-01 00:00:00
abstract: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 strate...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2012.06.001
更新日期:2012-09-01 00:00:00
abstract:OBJECTIVE:Developmental exposure to dioxin-like compounds has been associated with cognitive and motor impairments in children. These toxicants have been shown to be thyroid toxicants in animal studies. Therefore, the objective of this study was to quantify the overall dioxin-like activity in maternal serum and determi...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2005.08.013
更新日期:2005-12-01 00:00:00
abstract:OBJECTIVE:Placental passage of the angiotensin-converting enzyme inhibitors temocapril and enalapril was investigated in a placental perfusion model. STUDY DESIGN:In an open system a placental lobe was perfused on both the maternal and the fetal side with a blood-free medium containing the test substances plus a refer...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(96)70587-2
更新日期:1996-05-01 00:00:00
abstract:OBJECTIVE:The objective of the study was to examine the rates of gestational diabetes mellitus (GDM) associated with both maternal and paternal race/ethnicity. STUDY DESIGN:This was a retrospective cohort study of all women delivered within a managed care network. Rates of GDM were calculated for maternal, paternal, a...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2010.01.082
更新日期:2010-06-01 00:00:00
abstract:OBJECTIVE:We report four cases of neonatal alloimmune thrombocytopenia (NATP) in pregnancies achieved with in vitro fertilization. STUDY DESIGN:Three cases used surrogate carriers, and the fourth a donor egg. Sera from gestational carriers were tested for platelet antibodies by flow cytometry and enzyme-linked immunos...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2004.09.006
更新日期:2005-02-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to evaluate which variables predict neonatal depression in vaginal deliveries that result in permanent brachial plexus injury. STUDY DESIGN:With the use of a data set of litigated vaginal deliveries (n = 103 deliveries) from 1978 through 1999 that resulted in permanent brachial ...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1067/mob.2002.127128
更新日期:2002-10-01 00:00:00
abstract:OBJECTIVE:Our purpose was to determine what factors occurring after digital separation of the chorionic membranes from the lower uterine segment (membrane stripping) are involved in observed clinical changes compared with patients not so treated. STUDY DESIGN:Thirty patients were randomly divided among a study populat...
journal_title:American journal of obstetrics and gynecology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/0002-9378(93)90134-5
更新日期:1993-07-01 00:00:00
abstract:OBJECTIVE:The objective of this study was to critically review the indications, outcomes, complications, and costs of laparoscopically assisted vaginal hysterectomy in comparison with abdominal and vaginal hysterectomy. STUDY DESIGN:The operating room log was reviewed to determine the number and route of hysterectomie...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(93)90679-d
更新日期:1993-06-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to review the population incidence of congenital gastroschisis in Western Australia over the past 2 decades. STUDY DESIGN:A population-based incidence study of congenital gastroschisis from 1980 to 2001. Maternal and perinatal outcome data were collected to ascertain incidence, ...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1067/s0002-9378(03)00819-6
更新日期:2003-09-01 00:00:00
abstract::Pregnancy and peripartum/perinatal periods are characterized by significant biologic as well as psychosocial processes and changes that influence the 2 individuals at focus (mother and fetus), as well as their interactions with the immediate environment. Multiple intertwined pathologic pregnancy processes (hormonal, b...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章,评审
doi:10.1016/j.ajog.2005.02.103
更新日期:2005-10-01 00:00:00
abstract::The effect of obesity alone was investigated among 16,858 women who were delivered of their infants within a 12-month period. Complete analysis was possible for 9667 patients who were divided into four weight categories and separated into two groups, with and without complications. Perinatal mortality, infant size, an...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(85)80029-6
更新日期:1985-05-15 00:00:00
abstract:BACKGROUND:Surgical abortion is a generally safe procedure. Obesity is a known risk factor for complications in other surgical procedures, but insufficient information exists to determine the effects of increasing body mass index on the risk of surgical abortions. OBJECTIVE:The purpose of this study was to determine w...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2017.10.018
更新日期:2018-02-01 00:00:00
abstract:OBJECTIVE:Our purpose was to investigate perfusion pressure changes ex vivo induced by angiotensin II on fetoplacental vasculature pretreated with low-dose acetylsalicylic acid. STUDY DESIGN:Two cotyledons from each of 12 placentas were perfused. The intervillous space of one cotyledon was infused with acetylsalicylic...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(97)70021-8
更新日期:1997-11-01 00:00:00
abstract::Systemic distribution of radioactive colloidal chromic phosphate P 32 after intraperitoneal instillation was studied in 10 patients with ovarian or endometrial malignancies. Seven patients without ascites received chromic phosphate P 32 for positive peritoneal washings, rupture of the capsule of the cyst during operat...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(84)80014-9
更新日期:1984-09-15 00:00:00
abstract::Oral contraceptives (OCs) raise the plasma levels of some clotting factors, especially factor VII. Until recently, however, there has been no evidence for a relationship between high levels of clotting factor and the onset of clinically manifest vascular disease. It has not been established, on a preliminary basis, th...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(16)32484-x
更新日期:1982-03-15 00:00:00
abstract:OBJECTIVE:The purpose of this study was to determine the accuracy of live-birth certificates and hospital discharge data that reported of pre-existing maternal medical conditions and complications of pregnancy. STUDY DESIGN:We conducted a population-based validation study in 19 non-federal short-stay hospitals in Wash...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2005.02.096
更新日期:2005-07-01 00:00:00
abstract:OBJECTIVE:Fasting during pregnancy stimulates preterm delivery in animals and increases women's risk for preterm delivery. Fasting stimulates hypothalamic corticotropin-releasing hormone production in animals. Elevated maternal corticotropin-releasing hormone concentrations are associated with preterm birth. We hypothe...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1067/mob.2001.115863
更新日期:2001-08-01 00:00:00
abstract:OBJECTIVE:The aim of this study was to evaluate whether the amniotic viral load of mothers with primary cytomegalovirus infection correlate with fetal or neonatal outcomes. STUDY DESIGN:Sixty-eight of 138 pregnant women with primary infection defined by immunoglobulin G seroconversion or the presence of immunoglobulin...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1067/mob.2000.106347
更新日期:2000-08-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to determine if gap junctions are a necessary component of the human laboring uterus and if their presence in myometrium is a prerequisite for both term and preterm labor. STUDY DESIGN:We obtained 27 human myometrial samples at cesarean section or nongravid hysterectomy. Gap jun...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(11)90806-0
更新日期:1993-05-01 00:00:00
abstract::One hundred forty-nine consecutive patients who had surgery from May 1890 through December 1986 were evaluated to assess the functional and anatomic results of the paravaginal defect repair for stress urinary incontinence. All patients had their preoperative assessment, operative procedure, and postoperative follow-up...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(89)90867-3
更新日期:1989-06-01 00:00:00
abstract:OBJECTIVES:To evaluate the relationship of hormone (estrogen receptor alpha, estrogen receptor beta, progesterone receptor) and growth factor receptor (insulin-like growth factor receptor, human epidermal growth factor receptor 2) expression with disease progression in uterine carcinosarcoma. STUDY DESIGN:Immunohistoc...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2008.12.012
更新日期:2009-04-01 00:00:00
abstract:OBJECTIVE:This study was undertaken to determine the relationship among cervical lactoferrin concentration, other cervical markers potentially related to infection, and spontaneous preterm birth. STUDY DESIGN:Cervical lactoferrin concentrations obtained at 22 to 24 weeks' gestation among 121 women who had a spontaneou...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1067/mob.2000.104211
更新日期:2000-03-01 00:00:00
abstract:OBJECTIVE:Our objective was to ascertain long-term tolerability and effects of a novel, low-dosage continuous progestin-cyclic estrogen regimen on vasomotor flushing, vaginal bleeding patterns, bone density, and plasma lipoprotein lipids. STUDY DESIGN:Eighteen postmenopausal women with climacteric symptoms received lo...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(92)91842-x
更新日期:1992-01-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to examine whether women with gestational diabetes mellitus (GDM) and their offspring have reduced endothelial progenitor cell subsets and vascular reactivity. STUDY DESIGN:Women with GDM, healthy control subjects, and their infants participated. Maternal blood and cord blood we...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2010.10.913
更新日期:2011-03-01 00:00:00
abstract:OBJECTIVE:Our objective was to determine any associations among midtrimester cervical fluid sialidase activity, bacterial vaginosis, and subsequent spontaneous preterm birth. STUDY DESIGN:In this nested case-control study all patients (n = 126) with spontaneous preterm birth at <35 weeks' gestation and selected contro...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(99)70609-5
更新日期:1999-05-01 00:00:00