Abstract:
:Because of the potential of dihydropyridine calcium channel blockers in the management of premature labor, we have studied the direct effects of nitrendipine on actomyosin in the pregnant and nonpregnant uterus and in the term human placenta. Actomyosin adenosinetriphosphatase in the three tissues and another model of actin-myosin interaction, superprecipitation of placental actomyosin, were inhibited by nitrendipine. The inhibition was not diminished by high concentrations of calcium. To identify the mechanism, placental myosin was phosphorylated in the absence and presence of 0.8 X 10(-4) mol/L of nitrendipine. The myosin phosphorylated in the presence of nitrendipine had lower actin-activated adenosinetriphosphatase, which is consistent with the inhibition of myosin light chain phosphorylation. However, nitrendipine did not affect the adenosinetriphosphatase activity of myosin nor did further reduce the adenosinetriphosphatase of the already phosphorylated placental actomyosin. Thus nitrendipine inhibition is directed to the phosphorylation reaction but not to the adenosinetriphosphatase site of myosin. Myometrial relaxation in vivo or in vitro occurs at the pharmacologic nitrendipine levels of 10(-9) to 10(-8) mol/L, which is at least 10,000 times lower than that of the concentration of 50% inhibition of myosin light chain phosphorylation (0.0026 +/- 0.00015 mol/L of nitrendipine, mean +/- SEM) demonstrated in the present work. Because of this difference, the direct intracellular actions of dihydropyridine calcium channel blockers are not expected to cause adverse effects in the uteroplacental system when these drugs are used in the prevention or treatment of premature labor.
journal_name
Am J Obstet Gynecoljournal_title
American journal of obstetrics and gynecologyauthors
Sakamoto H,Huszar Gdoi
10.1016/0002-9378(86)90679-4subject
Has Abstractpub_date
1986-02-01 00:00:00pages
402-7issue
2eissn
0002-9378issn
1097-6868pii
0002-9378(86)90679-4journal_volume
154pub_type
杂志文章abstract:OBJECTIVE:The objective of this study was to test the hypothesis that cocaine alters placental prostaglandin production in vitro. STUDY DESIGN:Placentas were obtained from healthy women (n = 6) after normal vaginal delivery at term. Placental explants (300 mg) were incubated in duplicate at 37 degrees C in the presenc...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(94)90015-9
更新日期:1994-10-01 00:00:00
abstract:BACKGROUND:It is not well-characterized whether attempting operative vaginal delivery is a safe and effective alternative among women who undergo a trial of labor after cesarean delivery who are unable to complete second-stage labor with a spontaneous vaginal delivery. OBJECTIVE:The purpose of this study was to compar...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2017.01.013
更新日期:2017-04-01 00:00:00
abstract:OBJECTIVE:Our aim was to determine whether there was a cerclage height threshold associated with spontaneous preterm birth in patients with an ultrasound-indicated cerclage. STUDY DESIGN:We performed a retrospective cohort study of women with an ultrasound-indicated cerclage. Functional cervical length and the cerclag...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2008.09.021
更新日期:2009-05-01 00:00:00
abstract:OBJECTIVE:We sought to determine the long-term efficacy, safety, and urodynamic effects of the Mersilene mesh suburethral sling in treating complicated forms of genuine stress incontinence. STUDY DESIGN:Two hundred women diagnosed with genuine stress incontinence, complicated by recurrence, intrinsic sphincter deficie...
journal_title:American journal of obstetrics and gynecology
pub_type: 临床试验,杂志文章
doi:10.1067/mob.2001.116370
更新日期:2001-07-01 00:00:00
abstract:OBJECTIVES:We determined which factors are associated with survival and good short-term neurologic outcome in newborns of 23 to 25 weeks' gestation. STUDY DESIGN:We retrospectively reviewed the charts of all (n = 82) infants born alive at our hospital at 23 to 25 weeks' gestation from 1988 through 1991. We used univar...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(94)70139-3
更新日期:1994-05-01 00:00:00
abstract:OBJECTIVE:To test the effect of prolactin (PRL) on expression of proinflammatory cytokines and matrix metallopeptidase 9 (MMP-9) in vitro. STUDY DESIGN:Tissue explants were incubated from 4 to 48 hours alone or in the presence of 500 ng/mL PRL, and mRNA expression in tissues and secretion of interleukin (IL)-1β, tumor...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2014.01.039
更新日期:2014-07-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to define the rate of neoplasia in prophylactic surgical specimens with the use of a careful surgical and pathologic protocol in a prospective study of high-risk women who were undergoing risk-reducing salpingo-oophorectomy. Outcomes of interest were neoplasia that was identified...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2006.03.006
更新日期:2006-06-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to compare alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol levels in women who take protease inhibitors and those women who do not. STUDY DESIGN:This retrospective review from August 2000 to May 2003 was performed for maternal serum screen results, medi...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2004.05.046
更新日期:2004-09-01 00:00:00
abstract:OBJECTIVE:The objective of the study was to examine weight and its relationship to glucose intolerance during pregnancy. STUDY DESIGN:Women were classified into mutually exclusive glucose tolerance groups; impaired glucose tolerance of pregnancy defined as 1 high value on the oral glucose tolerance test, gestational d...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2006.05.017
更新日期:2006-12-01 00:00:00
abstract::Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clin...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章,评审
doi:10.1016/j.ajog.2017.06.003
更新日期:2017-09-01 00:00:00
abstract:OBJECTIVES:Our purpose was to determine whether blockade of inducible or endothelial nitric oxide synthesis prevents maternal vasodilation and blunting of angiotensin II responsiveness in the pregnant rat. STUDY DESIGN:Pregnant and nonpregnant rats were given (1) drinking water alone (untreated), (2) drinking water co...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(97)70404-6
更新日期:1997-05-01 00:00:00
abstract::Components of fetal behavioral state organization reflect the successful integration of the central nervous system, have a specific developmental timetable, and can be studied with fetal ultrasonographic techniques. To test the hypothesis that evaluation of state organization is a marker of abnormal central nervous sy...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(89)90380-3
更新日期:1989-09-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to evaluate whether maternal febrile illnesses in early pregnancy are associated with increased risk for congenital heart defects in the offspring and whether such risk is mitigated by multivitamin supplement use. STUDY DESIGN:From a multistate population-based case-control stud...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2013.10.880
更新日期:2014-04-01 00:00:00
abstract::All pregnant women, regardless of age, should be offered screening or invasive testing for chromosomal abnormalities at <20 weeks' gestation. Noninvasive prenatal screening for fetal aneuploidy with the use of cell-free DNA (cfDNA) is a screening method that offers high sensitivity and specificity in validation studie...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2015.05.004
更新日期:2015-07-01 00:00:00
abstract::Gynecologic cancer records of 4,238 patients treated between 1956 and 1974 were reviewed. Sixteen patients developed noeplasia in the cervix or vagina 10 or more years following pelvic irradiation. Three patients had squamous carcinoma in situ; the other 13 patients had invasive squamous cancer involving the upper vag...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(77)90445-8
更新日期:1977-03-01 00:00:00
abstract::Patients with pregnancy-induced hypertension have higher prostaglandin (PG) F concentrations in radial arterial blood (0.39 +/- 0.03 ng/ml) than control subjects (0.24 +/- 0.03 ng/ml) and higher (PGE plus PGF) concentrations in uterine venous blood obtained at the time of cesarean section (1.62 +/- 0.18 versus 1.03 +/...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(83)90333-2
更新日期:1983-01-01 00:00:00
abstract::The effect upon fetal breathing movements (FBM) in 49 women with uncomplicated pregnancies who inhaled 5% carbon dioxide in air for 15 minutes was observed with an ADR real-time ultrasound scanner. A threefold increase in FBM occurred during the inhalation of CO2. ...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(80)90867-4
更新日期:1980-02-01 00:00:00
abstract::The American College of Obstetricians and Gynecologists recommends that women with previous low transverse cesarean sections who are candidates for a trial of labor should undergo such a trial only in a special environment. Such recommendations imply that these women are at greater risk than the general population for...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(86)90321-2
更新日期:1986-11-01 00:00:00
abstract:OBJECTIVE:The objective of this study was to compare different management strategies for women at risk for cervical incompetence. STUDY DESIGN:In an ongoing randomized trial patients with a previous preterm delivery at <34 weeks' gestation who met clinical criteria for the diagnosis of cervical incompetence are alloca...
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:10.1067/mob.2000.108874
更新日期:2000-10-01 00:00:00
abstract::One hundred fifty-eight intravenous saline solution infusions (3 mmol Na per kilogram body weight) were performed in (1) normal primigravid women during the second and third trimesters and post partum, after 1 week of either a high, low, or ad libitum salt intake; (2) normotensive primigravid women during midpregnancy...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(88)80071-1
更新日期:1988-08-01 00:00:00
abstract::The recent birth of octuplets unleashed a firestorm of publicity, casting a harsh light on the mother and her presumed inadequacies as a parent. It also raised questions about the role of reproductive endocrinologists. Herein we consider 3 aspects of this question: should reproductive endocrinologists consider the eco...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2009.04.053
更新日期:2009-07-01 00:00:00
abstract::An improved statistical method for assessing the efficacy of intrauterine contraception is presented. This method, called the log-rank method, is based on a daily life table, which yields the best estimates of the cumulative net termination probabilities. It provides a sensitive chi-square test statistic to detect dif...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(77)90632-9
更新日期:1977-06-01 00:00:00
abstract::From January 1, 1970 to July 1, 1976, 128 women had hydatidiform moles evacuated at the Los Angeles County-University of Southern California Women's Hospitals. Of the 121 patients with follow-up, persistent trophoblastic disease (TD) was diagnosed in 32 (26.4 per cent). Remission was achieved in all treated patients. ...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(77)90562-2
更新日期:1977-06-15 00:00:00
abstract:OBJECTIVE:A controversy exists regarding the time to monitor blood glucose in the diabetic pregnancy (60 or 120 minutes after meals). Using a novel approach that provides continuous measurement of blood glucose, we sought to determine postprandial glucose profile in the diabetic pregnancy. STUDY DESIGN:Subjects were c...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/j.ajog.2004.01.055
更新日期:2004-08-01 00:00:00
abstract::To clarify the possible immunologic functions of the endometrium before implantation, supernatants from explant cultures of human endometrial tissues were examined for effects on mixed lymphocyte reaction and phytohemagglutinin M-stimulated cultures. Supernatants obtained from both proliferative and secretory phase en...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(87)80095-9
更新日期:1987-10-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to investigate the potential efficacy of high-intensity focused ultrasound for the treatment of uterine fibroid tumors in a nude mouse model. STUDY DESIGN:A total of 60 female athymic nude mice were inoculated subcutaneously with 3 to 5 x 10(6) ELT-3 cells, a uterine fibroid tum...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1067/mob.2000.105347
更新日期:2000-07-01 00:00:00
abstract::Fetal heart rate (FHR) is influenced by the central nervous system, cardiac automatism, biochemical factors, etc. Changes in FHR were correlated with the anatomic defect in autopsy material from 20 anencephalic infants, and, on this basis, the following hypotheses were formed, subject to later experimental proof. (1) ...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(84)90199-6
更新日期:1984-05-15 00:00:00
abstract:OBJECTIVE:In a seroepidemiologic study the effects of pregnancy and other factors on humoral response to human papillomavirus type 16 infection were examined. STUDY DESIGN:Multiple serum samples were taken at 3-month intervals for 15 months from 77 pregnant and 85 nonpregnant women. Serologic response to human papillo...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/s0002-9378(98)80026-4
更新日期:1998-02-01 00:00:00
abstract:OBJECTIVE:We sought to establish the lowest dose of 3-keto-desogestrel, when added to a copper-releasing intrauterine contraceptive device, that is needed to reduce menstrual blood loss to a very low level and to treat (essential) menorrhagia successfully. STUDY DESIGN:A double-blind group comparative study was design...
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:10.1067/mob.2000.104805
更新日期:2000-03-01 00:00:00
abstract:OBJECTIVE:The purpose of this report is to bring to the attention of obstetric care providers the occurrence in pregnancy of a threatening pulmonary syndrome caused by hantavirus infection. STUDY DESIGN:Two recent cases of hantavirus pneumonitis in pregnancy, one complicated by adult respiratory distress syndrome, are...
journal_title:American journal of obstetrics and gynecology
pub_type: 杂志文章
doi:10.1016/0002-9378(94)90298-4
更新日期:1994-08-01 00:00:00