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At least 19 recordsLinked to original sources
PubMed1993

[The subjects of the controversy of energy theory and the concept of "labor intensity" in labor physiology from the 1930's to 1950's in Japan. Part 2: Physiological "labor intensity" and methodology in labor science].

I analyzed the controversy and concept of "labor intensity" in labor physiology, and my opinion is as follows: 1) The energy theory, which measured the human actions with the consumption of energy, considered only the physiological concept of labor intensity, without acknowledging the other aspects of the human being such as the psychological phenomenons, etc. It was one of the views to consider the human and the machine as the same thing. 2) Another theory, which criticizes the energy theory and its connection to energical "labor intensity", was proposed by Utsumi in 1950's and Teruoka (1947-51). 3) I emphasize that we must pay more attention to the methodology when we study the work loads and work conditions, not only by the physiological and psychological methods but also by the socio-economical methods.

Energy Transfer↗
PubMedDate not supplied

Differential expression of transforming growth factor-beta 1 and transforming growth factor-beta receptors in myometrium of women with failed induction of labor, no labor, and preterm labor.

OBJECTIVE: Comparative analysis of transforming growth factor-beta 1 (TGF-beta 1) and TGF-beta receptor type I and type II messenger RNA (mRNA) and protein expression in myometrium of women who had unsuccessful labor induction, with those without labor or in preterm labor complicated by chorioamnionitis. METHODS: Small segments of myometrium were collected from women who were undergoing cesarean delivery for unsuccessful labor induction (n = 5), elective cesarean without labor (n = 5), or cesarean delivery for complications related to preterm labor and chorioamnionitis (n = 5). Total RNA was isolated from these tissues and subjected to competitive quantitative reverse-transcription-polymerase chain reaction (Q-RT-PCR) to determine the level of TGF-beta 1, and TGF-beta type I and type II receptor mRNA expression. Tissue sections were prepared from paraffin-embedded specimens and immunostained for TGF-beta 1 and receptor proteins using specific polycolonal antibodies. The data were analyzed by impaired Student t test and Kruskal-Wallis analysis of variance. RESULTS: Myometrium from women who had unsuccessful labor induction expressed higher levels of TGF-beta 1 mRNA (2.21 +/- 0.28 x 10(6) copies/microgram of total cellular RNA) than those with preterm labor (4.53 +/- 0.2 x 10(5) copies), or without labor [3.13 +/- 2.6 x 10(4) copies (P < .05)]. The level of TGF-beta type I receptor mRNA expression did not vary; however, type II receptor expression was significantly lower in myometrium from preterm labor (1.36 +/- 0.36 x 10(5) copies) compared with those from unsuccessful labor induction (3.42 +/- 0.42 x 10(6) copies) or without labor (9.65 +/- 3.2 x 10(5) copies). Immunoreactive TGF-beta 1 and TGF-beta receptor proteins were present in all myometrial tissues, and their intensity reflected that of the mRNA expression in these tissues. CONCLUSION: TGF-beta 1 and TGF-beta type II receptors are expressed differently in myometrium of women who had unsuccessful labor induction compared with those without labor or with preterm labor complicated by chorioamnionitis. Because TGF-beta is a key regulator of tissue remodeling which is central to initiation of normal labor, alterations in TGF-beta and/or TGF-beta receptor expression may lead to changes in the outcome of labor, at least at the myometrial level.

Cesarean Section↗
PubMed2000

Graphic analysis of actively managed labor: prospective computation of labor progress in 500 consecutive nulliparous women in spontaneous labor at term.

OBJECTIVE: Active management has been shown to shorten the length of labor and reduce the incidence of prolonged labor. We examined the influence of this protocol on the rate of cervical dilatation by calculating a mean partogram to explain how this acceleration is achieved. STUDY DESIGN: We retrospectively analyzed partograms of cervical dilation in 500 consecutive nulliparous women in spontaneous labor at term with a singleton fetus in a cephalic presentation; cesarean deliveries were not excluded. Mean cervical dilations at admission and mean time intervals to reach 2, 3, 4, 6, 8, and 10 cm of dilatation and delivery were calculated, with 95% confidence intervals, both for the whole cohort and specifically in women with cervical dilatations <3 cm at admission. These data were used to construct mean partograms. RESULTS: The mean duration of labor was 6.1 hours. The mean cervical dilatation at admission was 1. 7 cm; all but 2.8% were delivered within 12 hours. The cesarean rate was 5.4%. The mean partogram, with narrow 95% confidence intervals, shows a rapid active phase after a much shorter latent phase than reported in other analyses of labor. CONCLUSION: Active management reduces the duration of first labor mainly by shortening the latent phase in association with amniotomy at very early cervical dilatations and does not delay the diagnosis of labor until the active phase has begun.

Adolescent↗
PubMed1987

A dynamical model of labor-market change in international labor migrations when demand for labor is exogenous.

"Relatively little is known about the long-run behavior of international labor migrations. One of the biggest concerns in immigration debates relates to the continued pressure on the borders of the wealthy countries. This immigration pressure will decline significantly only if the poor nations manage to provide more high-wage jobs. An earlier model of international labor migration is used to derive additional insights into the growth and decline of labor supply in different labor markets resulting from migration. Particular attention is paid to labor demand growth requirements in a sending country so that out-migration will slow down and eventually stop."

Demography↗
PubMed1987

Changes in the plasma prostaglandin F2 alpha metabolite before and during spontaneous labor and labor induced by amniotomy, oxytocin and prostaglandin E2.

To elucidate the role of endogenous prostaglandin F2 alpha in spontaneous and induced labor, plasma concentrations of 13, 14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were determined before the onset of labor, at onset of labor, during active labor, at the crowning of the fetal head, and 1 and 2 hours after delivery. Patients in spontaneous labor and labor induced by amniotomy, oxytocin, and prostaglandin E2 were studied. The levels of plasma PGFM in patients who entered spontaneous labor fell 2 to 3 weeks before delivery, whereas those in the induced labor group did not change until the time of induction. Although the levels of PGFM rose gradually with the progress of labor in all cases, the levels in the spontaneous labor were significantly lower in each stage than in the corresponding stage of induced labor. These results suggest that endogenous prostaglandin F2 alpha (PGF2 alpha) production decreases 2-3 weeks prior to the spontaneous onset of labor and is increased again as labor progresses, that the patterns of PGF2 alpha production are similar to each other during spontaneous labor and labor induced by various methods. Therefore, it is felt that endogenous PGF2 alpha may participate in the progress of all kinds of labor.

Adult↗
PubMedDate not supplied

Increase in prostaglandin H synthase 2, but not prostaglandin F2alpha synthase mRNA in intrauterine tissues during betamethasone-induced premature labor and spontaneous term labor in sheep.

OBJECTIVE: Prostaglandin F synthase (PGFS) catalyzes reduction of prostaglandin H(2) to PGF2alpha. No information exists on PGFS expression and regulation during pregnancy, either mRNA or protein, in relation to labor in uterine tissues in any species. We characterized PGFS mRNA expression in ovine myometrium, endometrium, maternal and fetal placenta in betamethasone-induced premature labor and spontaneous term labor using our cloned ovine PGFS riboprobe. Prostaglandin H synthase (PGHS) 2 mRNA was evaluated simultaneously as a control whose pregnancy related changes are well known. METHODS: Poly-A or total RNA from fetal placenta, myometrium, and endometrium in control ewes at 143-147 days of gestational age (dGA, TCNL, n = 6), and ewes in spontaneous term labor at 145-147 dGA (STL, n = 6) and endometrium and maternal and fetal placenta in early control ewes not in labor (ECNL, n = 6) and betamethasone induced labor at 128-135 dGA (BL, n = 6) were analyzed for PGHS2 and PGFS mRNA. RESULTS: PGFS mRNA did not change at spontaneous term labor in myometrium, endometrium, and fetal placenta. PGFS mRNA decreased during betamethasone-induced premature labor in endometrium and maternal placenta (P < .05), but remained unchanged in fetal placenta and myometrium. PGHS2 mRNA increased in endometrium, placenta, and myometrium during betamethasone-induced premature labor and spontaneous term labor. CONCLUSION: Increased PGHS2, but not PGFS mRNA was tightly associated with the onset of betamethasone-induced premature labor as well as spontaneous term labor in the endometrium, placenta, and myometrium. Transcription of PGFS mRNA may not be the rate-limiting step in the pathway contributing to increased PGF(2alpha) at labor.

Animals↗
PubMed1987

Changes in plasma oxytocin, prostaglandin E1, and 13,14-dihydro-15-keto-prostaglandin F2 alpha during labor induced by prostaglandin E2 or F2 alpha and spontaneous labor.

To observe the changes in endogenous oxytocics during spontaneous and induced labor, the plasma concentrations of oxytocin, prostaglandin E1 (PGE1) and 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were measured during labor in 9 cases of spontaneous labor (group 1), 10 of PGE2-induced labor (group 2), and 7 of PGF2 alpha-induced labor (group 3). Unextracted samples were used for radioimmunoassay of oxytocin. PGE and PGF were extracted and separated for radioimmunoassays of PGE1 and PGFM. Although oxytocin levels in groups 1 and 3 did not change during labor or slightly increased toward delivery, those in group 2 decreased as labor progressed. The mean oxytocin in group 2 was significantly lower at the times of established labor (15.3 +/- 3.2 microU/ml, mean +/- SE) and crowing of the fetal head (10.8 +/- 2.0 microU/ml) than before labor (52.7 +/- 14.8 microU/ml). Plasma PGE1 levels in groups 1 and 3 were low and did not change during labor. Plasma PGFM levels in groups 1 and 2 gradually rose toward delivery. These results suggest that exogenous PGE2 suppresses oxytocin secretion during labor and stimulates endogenous PGF2 alpha production, that endogenous PGE1 may not play an important role in the progress of spontaneous and PGF2 alpha-induced labor, and that endogenous PGF2 alpha may participate in the promotion of all kinds of labor.

Alprostadil↗
PubMed2000

Effects of epidural fentanyl on labor pain during the early period of the first stage of induced labor in nulliparous women.

BACKGROUND AND PURPOSE: It is generally accepted that epidural injection with local anesthetics and narcotics administered when the cervix has dilated to a diameter exceeding 4 cm can adequately control labor pain. However, many nulliparous women still suffer from labor pain for a few hours prior to the administration of epidural analgesia. This study examined the effectiveness of relief of labor pain obtained by injection of narcotics epidurally once the labor pain begins and the subject requests analgesia. METHODS: Subjects scheduled for induced labour were divided into three groups: Group A (n = 60) received 5 x 10(-4)% fentanyl (10-20 mL) administered epidurally to relieve early first-stage labor pain. Group B (n = 60) received no analgesic in the early first stage of labor. For groups A and B, when cervical dilatation exceeded 4 cm, 10 to 15 mL of 5 x 10(-2)% bupivacaine and 2 x 10(-4)% fentanyl were injected epidurally and a continuous low dosage was maintained until full dilatation of the cervix resulted. Group C (n = 198) received no analgesic during the entire labor course. RESULTS: There were no significant differences in the duration of the early period of the first stage of labor, the duration of the late period of the first stage, the duration of the second stage, the Apgar score, or the arterial blood gas of neonates among the three groups. However, group C had a significantly higher cesarean section rate (28.8%) than group A (16.7%) or group B (15%). Pain scores assessed with the Visual Analog Scale (VAS) throughout the entire labor course, were lower in group A than in group B; particularly during the early period of the first stage. The VAS scores in both groups A and B were significantly lower than those in group C during the late period of the first stage of labor. CONCLUSIONS: The results indicate that once labor pain begins and the subject requests analgesia, epidural injection with fentanyl alone can relieve labor pain during the early period of the first stage. The analgesia does not cause adverse effects to the mothers or neonates. In addition, the labor course and the method of delivery are not affected.

Adult↗
PubMed2003

Maternal morbidity associated with cesarean delivery without labor compared with spontaneous onset of labor at term.

OBJECTIVE: To estimate the maternal morbidity associated with cesarean deliveries performed at term without labor compared with morbidity associated with spontaneous labor. METHODS: A 14-year, population-based, cohort study (1988-2001) using the Nova Scotia Atlee Perinatal Database compared maternal outcomes in nulliparous women at term undergoing spontaneous labor for planned vaginal delivery with singleton, cephalic presentation and nulliparous women delivering by cesarean without labor. RESULTS: From a total of 18,435 pregnancies, which satisfied inclusion and exclusion criteria, 721 were cesarean deliveries without labor. There were no maternal deaths or transfers for intensive care. There was no difference in wound infection, blood transfusion, or intraoperative trauma. Women undergoing cesarean deliveries without labor were more likely to have puerperal febrile morbidity (relative risk [RR] 2.2; 95% confidence interval [CI] 1.1, 4.5; P=.03), but were less likely to have early postpartum hemorrhage (RR 0.6; 95% CI 0.4, 0.9; P=.01) compared with women entering spontaneous labor. Subgroup analyses of maternal outcomes in women delivering by spontaneous and assisted vaginal delivery and cesarean delivery in labor were also performed. The highest morbidity was found in the assisted vaginal delivery and cesarean delivery in labor groups. CONCLUSION: The increased maternal morbidity in elective cesarean delivery compared with spontaneous onset of labor is limited to puerperal febrile morbidity. Maternal morbidity is increased after assisted vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor.

Adult↗
PubMed1983

Comparison of plasma oxytocin levels during spontaneous labor and labor induced by amniotomy, prostaglandin F2 alpha, and prostaglandin E2.

Plasma concentrations of oxytocin in nine spontaneous labors (group 1), nine amniotomy-induced labors (group 2), six prostaglandin F2 alpha-induced labors (group 3), and five prostaglandin E2-induced labors (group 4) were determined at the stages of 1 to 7 days preceding the onset of labor, onset of labor, and established labor, by means of unextracted radioimmunoassay. The levels of oxytocin in the stage preceding the onset of labor in group 1 were not significantly different from the levels of oxytocin in the corresponding stages in groups 2, 3, and 4. However, the levels of oxytocin in the stages of onset of labor and established labor in group 1 were significantly higher than those in the corresponding stages in groups 2, 3, and 4. These results suggest that oxytocin plays a leading role in the onset and progress of spontaneous labor, whereas something other than oxytocin might be involved in the labor induced by amniotomy alone or by prostaglandins.

Adult↗
PubMed1991

A comparative study of variables differentiating false labor from early labor.

False labor is a common and frustrating problem for women and health-care providers. The purpose of this study was to compare characteristics of true and false labor. A convenience sample of 65 women compared data for three groups who were observed for labor including: false labor, women who were dismissed and returned in true labor more than 48 hours later, impending labor, women who were dismissed but returned in true labor 48 hours or less later, and early labor, women who were admitted for true labor directly following an observation period. Psychosocial differences among the groups were measured by the Maternal Adjustment and Maternal Attitudes (MAMA) scale and a semistructured interview schedule. Chart reviews were conducted to measure physiologic differences and perinatal outcomes. Descriptive and inferential statistics were computed using the SPSSX program. The following variables were statistically significant at P less than .05 for false labor: somatic scores on the MAMA scale, contraction frequency, cervical Bishop scores, gestational age, and Apgar scores. Increased frequency of abnormal labor patterns, intervention with amniotomy, and oxytocin augmentation were observed in false labor subjects. The negative emotional responses of women who were interviewed suggest a need for further investigation of interventions to promote both physical comfort and psychological support.

Adolescent↗