Pharmacokinetic and Biochemical Profiling of Sodium Dichloroacetate in Pregnant Ewes and Fetuses

Sodium dichloroacetate (DCA) is an investigational drug that shows promise in the treatment of acquired and congenital mitochondrial diseases, including myocardial ischemia and failure. DCA increases glucose utilization and decreases lactate production, so it may also have clinical utility in reducing lactic acidosis during labor. In the current study, we tested the ability of DCA to cross the placenta and be measured in fetal blood after intravenous administration to pregnant ewes during late gestation and labor. Sustained administration of DCA to the mother over 72 hours achieved pharmacologically active levels of DCA in the fetus and decreased fetal plasma lactate concentrations. Multicompartmental pharmacokinetics modeling indicated that drug metabolism in the fetal and maternal compartments is best described by the DCA inhibiting lactate production in both compartments, consistent with our finding that the hepatic expression of the DCA-metabolizing enzyme glutathione transferase zeta1 was decreased in the ewes and their fetuses exposed to the drug. We provide the first evidence that DCA can cross the placental compartment to enter the fetal circulation and inhibit its own hepatic metabolism in the fetus, leading to increased DCA concentrations and decreased fetal plasma lactate concentrations during its parenteral administration to the mother. SIGNIFICANCE STATEMENT: This study was the first to administer sodium dichloroacetate (DCA) to pregnant animals (sheep). It showed that DCA administered to the mother can cross the placental barrier and achieve concentrations in fetus sufficient to decrease fetal lactate concentrations. Consistent with findings reported in other species, DCA-mediated inhibition of glutathione transferase zeta1 was also observed in ewes, resulting in reduced metabolism of DCA after prolonged administration.

[Some biochemical parameters in the placenta in discoordinated and powerless labors]

A number of biochemical parameters (total nitrites and nitrates (NO(x)), cyclic guanosine monophosphate (cGMP), nitrotyrosine, medium-weight molecules (MCM) in the placenta were determined in women with gestosis during discoordinated and powerless labor. Thirty placentas (10 placentas from parturients after discoordinated labor, 10 from those after powerless labor, 10 placentas as a control group) were examined. Changes in the parameters under study were found to result in the development of nitroxide and oxidant stresses and endotoxicosis. The biochemical parameters should be considered as placental criteria for the differential diagnosis of labor anomalies in gestosis, such as powerless and discoordinated labors.

Prolonged labour associated with lower expression of syndecan 3 and connexin 43 in human uterine tissue

BACKGROUND

Prolonged labour is associated with greater morbidity and mortality for mother and child. Connexin 43 is a major myometrial gap junction protein found in human myometrium. Syndecan 3 seems to prevail in the human uterus among heparan sulphate proteoglycans, showing the most significant increase during labour. The aims of the present study were to investigate syndecan 3 and connexin 43 mRNA expressions and protein distributions in human uterine tissue during normal and prolonged labour.

METHODS

Uterine isthmic biopsies were collected from non-pregnant (n = 7), term pregnant women not in labour (n = 14), in normal labour (n = 7) and in prolonged labour (n = 7). mRNA levels of syndecan 3 and connexin 43 were determined by real time RT-PCR. The localization and expression were demonstrated by immunohistochemistry and confocal microscopy.

RESULTS

In women with prolonged labour, the mRNA expressions of syndecan 3 and Connexin 43 were considerably lower than the expression level at normal labour (p < 0.05). In term-pregnant tissue, the expression of syndecan 3 and connexin 43 did not differ significantly compared to non-pregnant and normal labour. The immunoreactivity of syndecan 3 was strong at normal labour, in contrast to prolonged labour, where both a weaker expression and an irregular distribution were detected. The immunoreactivity of connexin 43 increased until term and further stronger staining occurred at normal labour. At prolonged labour, the immunoreactivity was weaker and more unevenly distributed. At labour, a co-localization of syndecan 3 and connexin 43 could be demonstrated in the smooth muscle by confocal microscopy.

CONCLUSION

The high expression of syndecan 3 and connexin 43 and their co-localization to the smooth muscle bundles during normal labour, together with the significant reduction in prolonged labour, may indicate a role for these proteins in the co-ordination of myometrial contractility.

IL-1beta, IL-6 and IL-8 levels in gyneco-obstetric infections

OBJECTIVE: During pregnancy cytokines and inflammatory mediators stimulate the expression of prostaglandin, the levels of which determine the onset of labor. The aim of this work was to study interleukin IL-1beta, IL-6 and IL-8 levels in the vaginal discharge, serum and urine of pregnant women with genitourinary infection before and after specific treatment. One hundred and fifty-one patients were studied during the second or third trimester of their pregnancy. METHODS: The selected patients were: healthy or control group (n = 52), those with bacterial vaginosis (n = 47), those with vaginitis (n = 37), those with asymptomatic urinary infection (n = 15) and post-treatment. The level of cytokines was assayed by ELISA test. The Mann-Whitney U-test was used for statistical analysis. RESULTS: The IL-1beta levels in vaginal discharge were: control 103.5 +/- 24.2 pg/ml, bacterial vaginosis 1030 +/- 59.5, vaginitis 749.14 +/- 66.7l ( p < 0.0001), post-treatment 101.4 +/- 28.7. IL-6 values were similar in both control and infected groups, and there were no patients with chorioamnionitis. In vaginal discharge IL-6: control 14.2 +/- 3.9 pg/ml, bacterial vaginosis 13.2 +/- 3.8, vaginitis 13 +/- 4.2. IL-8 levels were: control 1643 +/- 130.3 pg/ml, bacterial vaginosis 2612.7 +/- 257.7, vaginitis 3437 +/- 460 (p < 0.0001), post-treatment 1693 +/- 126.6. In urine the results were: control 40.2 +/- 17 pg/ml, asymptomatic urinary infection 1200.7 +/- 375 (p < 0.0001). In patients with therapeutic success both IL-1beta and IL-8 returned to normal levels. CONCLUSIONS: Genitourinary infections induce a significant increase in IL-1beta and IL-8 levels in vaginal secretions, and IL-8 in urine as well. Both cytokines could be useful as evolutive markers of infection.

Lipid rafts, the sarcoplasmic reticulum and uterine calcium signalling: an integrated approach

The pathways involved in Ca2+ signalling in the uterus remain incompletely understood, impairing our ability to prevent preterm and difficult labours. In this review we focus on two elements in the pathway of Ca2+ signalling that have recently emerged as playing important roles: membrane lipid rafts and the sarcoplasmic reticulum. We examine the evidence for lipid rafts in the uterus and discuss their functional role. We suggest that the increases in cytosolic [Ca2+] and contractility that occur with raft disruption are due, at least in part, to effects on large conductance Ca2+-activated K+ (BK) channels that are localized to rafts. The role of the SR in contributing to subsarcolemmal cytosolic microdomains in uterus is evaluated, along with its interactions with ion channels on the plasma membrane. Thus, signalling microdomains play an important, but incompletely understood, role in the uterus, and integrating them into other Ca2+ signalling pathways is a challenge for further research. We suggest that the role of the SR changes in pregnancy, from promoting quiescence via BK channels or SR Ca2+ uptake, to promoting Ca2+ entry and contractility at term, and relate data on lipid rafts to clinical outcome in obese pregnant women.

Relationship between beta-hCG levels in cervicovaginal secretions and labor

OBJECTIVE

To determine whether levels of human beta-chorionic gonadotropin hormone (beta-hCG) in cervicovaginal secretions can predict the labor process.

METHODS

A total of 150 women admitted in active labor to the urgent delivery unit of a university hospital were enrolled in a prospective study. The beta-hCG level of each woman's cervicovaginal secretions was measured by radioimmunoassay on admission; then, beta-hCG levels were compared between 2 groups of 35 women, one in whom labor progressed normally and another in whom augmentation of labor with oxytocin was required.

RESULTS

There were significant differences in beta-hCG levels of cervicovaginal secretions between the spontaneous delivery group and the augmentation of labor group (130.72+/-64.51 mU/mL vs. 93.9+/-65.29 mU/mL) (P<0.05). A receiver-operating characteristic (ROC) curve analysis showed that the optimal cut-off value was 82 mU/mL, with a sensitivity of 66% and a specificity of 60%.

CONCLUSION

beta-chorionic gonadotropin hormone levels were significantly higher in the cervicovaginal secretions of women whose labor was progressing normally than in those who required augmentation of labor.

Markedly elevated levels of inflammatory cytokines in maternal serum and peritoneal washing during arrested labor

BACKGROUND

The role of inflammatory cytokines in the pathophysiology of arrested labor is currently unknown. We measured levels of inflammatory cytokines in maternal serum and peritoneal washings in arrested first stage of labor to assess the possible involvement of these mediators in this obstetric disorder.

METHODS

This was a prospective, case-control study involving 15 women who underwent cesarean section for arrested cervical dilatation (group I), 15 controls who were operated during active labor for nonreassuring fetal heart-rate tracing (group II) and 15 controls who were operated electively (group III). Blood samples were drawn from all women shortly before the operation. The presence of peritoneal fluid was assessed and peritoneal washings were obtained during the operation. All samples were assayed for the inflammatory cytokines interleukin (IL)-1beta, IL-6, IL-8 and soluble IL-2 receptor (sIL-2R) by solid-phase enzyme-linked immunosorbent assay (ELISA).

RESULTS

All women from group I and one patient (6.7%) from group II had some degree of peritoneal fluid accumulation, while none from group III had any. Serum samples from group I contained significantly higher IL-1beta, IL-6, IL-8 and IL-2R levels than both control groups. Peritoneal washings from group I contained significantly higher IL-1beta, IL-6 and IL-8 but similar IL-2R levels.

CONCLUSIONS

Arrested first stage of labor is associated with peritoneal fluid accumulation and increased levels of inflammatory cytokines in both serum and peritoneal fluids. Inflammatory cytokines may therefore be involved in the pathophysiology of arrested labor.

Changes of lipocalin-type prostaglandin D synthase level during pregnancy

AIM

Prostaglandin D (PGD), synthesized by lipocalin-type prostaglandin D synthase (L-PGDS), has marked effects on a number of biological processes, including the prevention of platelet aggregation and the relaxation of vascular smooth muscle. The aim of the study presented here was to examine the significance of L-PGDS in human pregnancy.

METHODS

We measured the concentration of plasma L-PGDS in pregnant and non-pregnant women, and the concentration of L-PGDS in the umbilical cord blood, amniotic fluid and urine of newborns by enzyme-linked immunoabsorbent assay. To determine the localization of L-PGDS, we performed immunohistochemical analysis. To evaluate the usefulness of diagnosis of rupture of membranes (ROM), we determined the concentration of L-PGDS in cervicovaginal secretions.

RESULTS

Pregnant women and non-pregnant women had similar L-PGDS concentrations (0.57 +/- 0.13 microg/mL vs 0.53 +/- 0.07 microg/mL). Umbilical cord blood, amniotic fluid and newborn urine contained higher L-PGDS concentrations (1.87 +/- 0.73 microg/mL, 2.62 +/- 0.86 microg/mL, 6.31 +/- 4.62 microg/mL, respectively) than maternal blood. The concentration of L-PGDS in amniotic fluid from 19 weeks onward was significantly greater than that at 15-18 weeks (3.201 +/- 0.384 microg/mL, n = 6 vs 1.735 +/- 0.477 microg/mL, n = 4; P < 0.05). Immunohistochemistry revealed that the amniotic cells of the placenta expressed L-PGDS. The sources of L-PGDS in amniotic fluid are fetus urine and amniotic cells. The concentration of L-PGDS in cervicovaginal secretions with rupture of membrane (ROM) were significantly higher than those without ROM.

CONCLUSION

The measurement of L-PGDS in cervicovaginal fluid was useful in the detection of ROM during pregnancy.

Connexin 43 expression in normal versus dysfunctional labor

OBJECTIVE

We sought to determine whether connexin 43 (Cx43), the major myometrial gap junction protein, is differentially expressed in normal versus dysfunctional labor.

STUDY DESIGN

Myometrial biopsies were obtained from 28 patients undergoing cesarean section and grouped into the following categories: (1) no labor, (2) dysfunctional labor, and (3) normal labor. Northern and Western analyses were performed to determine Cx43 messenger RNA (mRNA) and protein expression, respectively. Localization of Cx43 protein was determined by immunohistochemistry.

RESULTS

Labor was associated with increased Cx43 mRNA expression (P <.05). This association was not true for protein. There was no difference in mRNA or protein expression between patients with normal labor versus those with dysfunctional labor. The extent of Cx43 immunohistochemical staining was not significantly different among the groups (P >.05).

CONCLUSION

Dysfunctional labor is not associated with aberrant Cx43 mRNA or protein expression or with a reduction in immunodetectable Cx43 gap junctions.

Immunohistochemical assessment of progesterone, oestrogen and glucocorticoid receptors in bovine placentomes during pregnancy, induced parturition, and after birth with or without retention of fetal membranes

Steroid hormones play an important role in placental development. However, the exact cellular site of hormone action has not been evaluated in bovine placentomes. Thus, the present immunohistochemical study was designed to assess the distribution of progesterone receptors, oestrogen receptors and glucocorticoid receptors in bovine placentomes. Tissue specimens were obtained from cows at slaughter and from cattle during pre-term Caesarean section 27 h after prostaglandin administration, immediately after spontaneous parturition and from cattle that had retained the fetal membranes. Specific antibodies were used for receptor demonstration in tissue sections. Progesterone receptors were only detected in maternal connective tissue cells, whereas oestrogen receptors were also present in maternal crypt epithelium. At specific sites, both receptor immunoreactivities remained constant or changed significantly during pregnancy, were generally higher during Caesarean section and decreased post partum, but were less pronounced in cattle that released the fetal membranes than in those that retained the fetal membranes. Glucocorticoid receptors were evident in fetal connective tissue cells as well as in fetal and maternal blood vessels. Maternal crypt epithelial cells showed increasing immunoreactivities for glucocorticoid receptors during pregnancy. Receptor immunoreactivities tended to be lower after spontaneous parturition than during Caesarean section; these results were significant for progesterone and oestrogen receptors in animals that released the fetal membranes but not for those that retained the fetal membranes. The results indicate that in bovine placentome steroid hormone receptors are distributed in patterns that are specific to the type of cell, the stage of pregnancy and the tissue location, implying highly specific modulation of placental metabolism. Retention of the fetal membranes is reflected by altered placental receptor states at parturition.

Lamotrigine in pregnancy: pharmacokinetics during delivery, in the neonate, and during lactation

PURPOSE

To investigate the pharmacokinetics of lamotrigine (LTG) during delivery, during the neonatal period, and lactation.

METHODS

High-performance liquid chromatography was used to determine plasma and milk levels of LTG in nine pregnant women with epilepsy treated with LTG, and plasma levels in their 10 infants. Samples were obtained at delivery, the first 3 days postpartum, and at breast-feeding 2-3 weeks after delivery.

RESULTS

At delivery, maternal plasma LTG concentrations were similar to those from the umbilical cord, indicating extensive placental transfer of LTG. There was a slow decline in the LTG plasma concentration in the newborn. At 72 h postpartum, median LTG plasma levels in the infants were 75% of the cord plasma levels (range, 50-100%). The median milk/maternal plasma concentration ratio was 0.61 (range, 0.47-0.77) 2-3 weeks after delivery, and the nursed infants maintained LTG plasma concentrations of approximately 30% (median, range 23-50%) of the mother's plasma levels. Maternal plasma LTG concentrations increased significantly during the first 2 weeks after parturition, the median increase in plasma concentration/dose ratio being 170%.

CONCLUSIONS

Our data demonstrate a marked change in maternal LTG kinetics after delivery, possibly reflecting a normalization of an induced metabolism of LTG during pregnancy. LTG is excreted in considerable amounts in breast milk (the dose to the infant can be estimated to >/=0.2-1 mg/kg/day 2-3 weeks postpartum), which in combination with a slow elimination in the infants, may result in LTG plasma concentrations comparable to what is reported during active LTG therapy. No adverse effects were observed in the infants, however.

[Ozone hemotherapy and endogenous intoxication in gestoses]

The paper is concerned with the study of chief markers of endogenous intoxication such as bodily content of medium-weight molecules (MWM) in patients with grave forms of gestoses, as well as with quest for ways of initiating a correcting therapy. Results of complex studies permitted coming to the conclusion that endogenous intoxication in different forms of gestoses runs its course through stages. This validates not only MWM levels but peculiarities of their distribution in erythrocytes, blood plasma and urine of patients as well. In particular, a change in the urine MWM level depends on the functional state of the Kidneys. Decline in bodily content of the studied toxic substrates owing to inclusion of ozone hemotherapy in conventional intensive therapy of gestoses makes for an appreciable lessening of the degree of catabolic disturbances.

Lipid peroxidation in cord blood: a randomised sequential pairs study of prophylactic saline amnioinfusion for intrapartum oligohydramnios

OBJECTIVE

To determine the efficacy of prophylactic intrapartum amnioinfusion in reducing cord arterial lipid peroxide levels in cases of intrapartum oligohydramnios.

DESIGN

Sequential randomised pairs trial.

SETTING

Delivery suite of a teaching hospital, the Chinese University of Hong Kong.

POPULATION

Women with singleton, term pregnancy, cephalic presentation, clear amniotic fluid and an amniotic fluid index < or = 5 cm, with a normal intrapartum fetal heart rate tracing within 30 minutes of amniotomy.

METHODS

Selected patients were randomised either for prophylactic saline amnioinfusion or as control cases. Cord arterial lipid peroxide concentrations and acid base balance were determined at delivery.

MAIN OUTCOME MEASURES

Operative intervention for fetal distress, cord arterial malondialdehyde and organic hydroperoxide levels, pH and base excess.

RESULTS

Amnioinfusion was associated with significant reductions in the incidence of operative delivery for fetal distress and in lipid peroxide levels, an increase in base excess, but no significant alteration in pH.

CONCLUSIONS

Oligohydramnios in labour is associated with high levels of lipid peroxidation, reflecting cellular damage by release of free radicals following hypoxia reperfusion. Prophylactic intrapartum saline amnioinfusion is an effective technique for the reduction of lipid peroxidation and of the incidence of operative intervention for fetal distress but has no significant effect on overall operative delivery rates.

X-ray microanalysis of myometrium in parturient women at term

The purpose of this study was to investigate the elemental composition of myometrial cells from term parturient women with normal and dysfunctional labour. Myometrial biopsies were obtained from forty-four term pregnant women undergoing Cesarean section. The patients were categorized according to uterine activity as follows: before labour, normal labour, labour successfully augmented by oxytocin, oxytocin-resistant labour, and labour arrested by terbutaline. X-ray microanalysis of freeze-dried sections (16 mu m thick) of the myometrium was carried out. An increase in intracellular phosphorus level (p < .01) was noted in the normal labour group compared to before labour. In patients with normal labour, higher phosphorus (p < .009) and potassium (p < .005) were found compared to oxytocin resistant labour. Patients with oxytocin resistant labour had lower intracellular potassium (p < .0006) and phosphorus (p < .02), and higher chloride (p < .05) and sodium (p < .03) compared to levels found in patients who responded to oxytocin treatment. In dysfunctional (oxytocin-resistant) labour the ion distribution in the myometrial cells might be disturbed. The reduced level of potassium and phosphorus together with the high sodium and chloride levels found in patients with oxytocin resistant labour may be connected to an impairment in sodium-potassium pump and muscle dysfunction, clinically diagnosed as dystocia.

Maternal plasma and placental immunoreactive corticotrophin-releasing factor concentrations in infection-associated term and pre-term delivery

The present study aimed to investigate whether microbial invasion of the amniotic cavity affects maternal plasma or placental immunoreactive corticotrophin releasing factor (ir-CRF) concentrations in pregnant women with pre-term or term labour. A cross-sectional study was conducted collecting blood samples in: (1) women with pre-term labour and intact membranes (25-36 weeks), with or without microbial invasion of the amniotic cavity (subdivided into three groups: 1A, no microbial invasion of the amniotic cavity, delivery at term, n = 54; group 1B, delivery < 48 h, no microbial invasion of the amniotic cavity, n = 10; group 1C, delivery < 48 h, microbial invasion of the amniotic cavity, n = 8); (2) women at term, not in labour and without microbial invasion of the amniotic cavity (n = 15); (3) women in spontaneous active labour at term without (A) (n = 55) or with (B) (n = 16) microbial invasion of the amniotic cavity; and (4) healthy women not in labour at 25-36 weeks of gestation (n = 25). Specimens of trophoblast tissue were collected from pregnant women with pre-term labour (no microbial invasion of the amniotic cavity, n = 6; microbial invasion of the amniotic cavity, n = 4) or delivering at term (no microbial invasion of the amniotic cavity, n = 8; microbial invasion of the amniotic cavity, n = 4). A specific radioimmunoassay on acidic extracts of plasma or placental specimens was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Beneficial effect of epidural anesthesia on oxygen consumption in a parturient with adult respiratory distress syndrome

Multifactorial increases in oxygen consumption during labor may exceed available oxygen supply. Cumulative subclinical oxygen debt could be clinically detrimental to both patient and fetus. We have reported the use of continuous mixed venous oxygen saturation monitoring to identify changes in oxygen consumption after painful uterine contractions in a critically ill parturient. We used continuous venous saturation monitoring to document the effects of epidural analgesia on oxygen balance in our patient. The absence of venous desaturation with contractions after abatement of labor pains confirmed that pain was the major cause of increased oxygen consumption in this critically ill parturient. Broader use of mixed venous saturation monitoring may allow detection of oxygen deficits during labor and direct appropriate therapy in other critically ill parturients. Similar applications and results have been noted for other disease states in nonpregnant patients.

Elevation of amniotic fluid interleukin 6 (IL-6), IL-8 and granulocyte colony stimulating factor (G-CSF) in term and preterm parturition

We determined the levels of inflammatory cytokines such as interleukin 6 (IL-6) granulocyte-colony stimulating factor (G-CSF) and IL-8 in the amniotic fluids from women with premature or term delivery. Cytokines were detectable even in the absence of apparent infection (group 1), but much higher cytokine levels were found in cases of intrauterine infection, particularly in cases of premature delivery (group 2). In cases of term delivery (groups 3-5), all of the cytokine levels showed c. 3- to 4-fold increase during labor pain (group 4) and an 8- to 13-fold increase in the presence of endotoxin (group 5), in comparison with the levels in cases where neither factor was present (group 3). Regarding infection, the cytokine levels were 20- to 30-fold higher in chorioamnionitis-positive premature delivery group (group 2), than in the infection-negative group (group 1). All the cytokines were simultaneously induced in amniotic fluid by labor pain and infection, and a significant positive correlation was observed among these three cytokine levels. In-vitro culture system and immunohistochemical study indicated that the cytokines in the amniotic fluid appeared to originate from trophoblasts and decidual cells. Thus, infection and labor pain may trigger the production of inflammatory cytokines at term as well as premature delivery and the determination of these cytokine levels will be a good indication for the prediction of the presence of intrauterine infection.

Evaluation of oxygen desaturation events in singleton pregnancies

Previous investigators have demonstrated that oxygen desaturation may occur in laboring women. The purposes of this study were to identify groups at risk for desaturation and to seek correlation with newborn outcome. Volunteers in labor were evaluated for oxygen desaturation, analgesic exposure, magnesium sulfate administration, and various medical illnesses. Desaturations were noted more frequently in women exposed to narcotic analgesics, sedatives, and magnesium sulfate. A trend toward more desaturations in the women with preeclampsia was noted. Although desaturations related to narcotic analgesics and sedatives are most likely due to hypoventilation, the mechanism in women treated with magnesium sulfate is uncertain. Maternal peripartum desaturations did not result in unfavorable neonatal Apgar scores, cord blood gas measurements, or neonatal oxygen desaturation values, but the staff was aware of the events and prompt treatment was instituted.

Interleukin-1 alpha and interleukin-1 beta in preterm and term human parturition

Interleukin-1 (IL-1) has been implicated in the mechanism of human parturition in the setting of infection. The purpose of this study was to determine the effect of labor (term and preterm) and microbial invasion of the amniotic cavity on amniotic fluid (AF) concentrations IL-1 alpha and IL-1 beta. AF was retrieved by transabdominal amniocentesis from the following groups of women: midtrimester genetic amniocentesis (16 to 18 wk) (N = 15), preterm labor with intact membranes (21 to 36 wk) with or without infection (N = 72), preterm premature rupture of membranes (PROM) (N = 88), and term not in labor or in active labor with or without infection (N = 58). AF was cultured for aerobic and anaerobic bacteria as well as Mycoplasmas. IL-1 was measured with a commercially available immunoassay validated for AF (sensitivity: IL-1 alpha, 157 pg/ml; IL-1 beta, 50 pg/ml). All women at midtrimester had undetectable AF IL-1 alpha and IL-1 beta. Among women in preterm labor with positive AF cultures, IL-1 alpha and IL-1 beta were detectable in the AF in 86.6% (13/15) and 100% (15/15), respectively. In contrast, all women with negative AF cultures without labor (N = 36) had undetectable AF IL-1 alpha concentrations and 52.7% (19/36) had undetectable AF IL-1 beta concentrations. Histopathological chorioamnionitis was present in 92.8% (13/14) of patients who had positive AF cultures and detectable IL-1 in the AF. IL-1 was significantly higher in patients with preterm PROM, labor, and positive AF cultures than in the other subgroups of patients with preterm PROM.(ABSTRACT TRUNCATED AT 250 WORDS)

Insufficient remodelling of the uterine connective tissue in women with protracted labour

OBJECTIVE

To investigate the association between a slow progress of labour and insufficient remodelling of the uterine connective tissue.

DESIGN

An open comparative study.

SETTING

Danderyd Hospital, Department of Obstetrics and Gynaecology, referral centre.

SUBJECTS

Eleven women (study group) in oxytocin augmented labour but with an unripe cervix in whom vaginal delivery could not be accomplished and 12 women (normal labour group) in normally progressing spontaneous labour and a favourable cervix but who needed to be delivered by caesarean section due to signs of fetal distress.

INTERVENTIONS

At caesarean section tissue specimens were obtained from the fundus, the isthmus and the cervix uteri.

MAIN OUTCOME MEASURES

Collagen concentration and extractability, collagenolytic activity expressed as DNP-peptide hydrolytic activity and the concentrations of sulphated glycosaminoglycans (S-GAG) and hyaluronic acid (HA) in the tissue specimens.

RESULTS

Statistically significantly higher concentrations and lower extractability of collagen in the isthmus and the cervix uteri was found in women with slow progress of labour compared with those with normal labour.

CONCLUSIONS

An insufficient remodelling of the connective tissue in the cervix and isthmus uteri may contribute to slow progress of labour.

[The endocrine status of clinically conspicuous mares during the peripartum period]

The aim of the present investigations was to characterize the endocrine changes in the peripheral plasma during the periparturient phase of mares with a known history of obstetrical disorders. Blood plasma samples from 9 mares (8 mares during parturition, 1 mare during abortion) were collected and the following steroid hormones were radioimmunologically determined: progesterone (P4), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), estrone (E1), estrone sulfate (E1-S), estradiol-17 beta (E2), estriol (E3), cortisol and transcortin. In general, with the exception of cortisol, DHEA and transcortin, all steroid hormone levels declined significantly after parturition. Mean plasma concentrations of DHEA-S, the direct fetal precursor of estrone, were 6 times higher than DHEA. However, DHEA-S levels varied considerably between all mares as well as between daily values of the same mare. Levels of E1-S were found to be about thousand times higher than those of E1, E2, and E3. The rather low concentrations of E3 suggest that this hormone is mainly produced by peripheral conversion and that in the horse fetus the 16 alpha-hydroxylation of DHEA-S is lacking. Despite the fact that most of the examined mares showed signs of severe disease none of the investigated steroid hormones indicated any disturbances of gestation. It is concluded that, from the clinical point of view, serial determinations of E1-S plasma levels are the best way to prove the fetal well-being. However, it should be stressed, that even the E1-S values are no indicators for the onset of parturition or abortion.

Prostaglandins in dysfunctional labour; evidence for altered production of prostaglandin F2 alpha

Dysfunctional labour was studied in relation to prostaglandin concentrations in amniotic fluid and production by fetal membranes. Initial clinical validation of the model established the presence of hypokinetic labour with no evidence of obstruction to the fetal progress. Prostaglandin F2 alpha (PGF2 alpha) and 13, 14 dihydro-15-keto-prostaglandin-F2 alpha concentrations in the amniotic fluid were low despite relatively normal concentrations of prostaglandin E2. Membranes removed from patients with the condition released very low concentrations of PGF2 alpha from the amniotic side with no alteration on the choriodecidual side of the membrane. Studies of free and phospholipid-associated arachidonic acid indicated normal release of arachidonic acid in dysfunctional labour. No changes in amniotic fluid-related inhibitors and stimulators of prostaglandin synthetase were detected. It is suggested that PGF2 alpha production is impaired in dysfunctional labour and that this prostaglandin is primarily involved in the progress of labour.

[Effect of the hyperbaric oxygenation of animals and man on mitochondrial function in their tissues (based on EPR study data)]

The ration of differential intensities of EPR signal of free endogenous radicals of semiquinone type and iron-sulfur proteins recorded at the temperature of liquid nitrogen in tissues (R index) is proposed as a criterion for estimation of changes in the functional state of mitochondria in human and animal tissues treated with hyperbaric oxygenation (HBO). The increase in R value was observed in hearts of intact mice and rabbits treated with HBO in near-toxic doses. This indicates a shift in mitochondria redox state towards oxidation. The above effect was not observed in mitochondria from intact zone of myocardium in animals with experimental infarction, and the numbers of mitochondria in the tissue increased after HBO. HBO treatment of women with pathological pregnancy leads to the decrease in R value for placental mitochondria.

Amniotic membrane production of prostaglandin F2 alpha is reduced in dysfunctional human labor: results of in vivo and in vitro studies

Mobilization of arachidonic acid from glycerophospholipids and prostaglandin (PG) release from fetal membranes were studied in women with dysfunctional labor in the absence of cephalopelvic disproportion or fetal malposition. Using superfusion of intact amnion and chorion, we found a slight decrease in PGE and a more significant decrease in PGF release by the amniotic side of the fetal membrane obtained from women with dysfunctional labor compared to that in women with normal labor (PGE: normal labor, 2992 pg/cm2.h; dysfunctional labor, 1846 pg/cm2.h; P less than 0.05; PGF: normal labor, 662 pg/cm2.h; dysfunctional labor, 204 pg/cm2.h; P less than 0.02). Release of both prostanoids was significantly greater from the amniotic side in tissues obtained after labor compared to that in prelabor tissue. Analysis of arachidonic acid (by gas liquid chromatography) and phospholipid content (by two-dimensional thin layer chromatography) confirmed metabolic disposal of arachidonic acid from the amnion after the onset of labor. However, no difference in either phospholipid or phospholipase A2-releasable arachidonic acid of individual phospholipid classes was found in amnion tissue from women with normal and dysfunctional labor, suggesting similar activities of phospholipase A2 in these two groups. The finding of decreased free and phospholipase A2-releasable arachidonic acid of the total lipid extract of the amnion of women with dysfunctional labor could suggest further metabolic exhaustion of the substrate or failure of liberation of this fatty acid from glycerophospholipids by enzymes other than phospholipase A2, such as phospholipase C or diacyl and monoacylglycerolipases.

Differential regulation of prostaglandin production by inhibitors and stimulators in amniotic fluids during normal and dysfunctional labor

The regulatory effect of amniotic fluid factors on prostaglandin production by sheep seminal vesicle prostaglandin synthetase was determined using samples obtained before and after the onset of labor. Variations in the enzyme incubation conditions permitted the effects on both prostaglandin E (PGE) and prostaglandin F (PGF) production to be assessed. Amniotic fluid obtained before the onset of labor and during early labor resulted in a net stimulation of PGE production and no difference was observed between these two groups. Samples obtained before and during early labor had no net effect on PGF production. However, when samples obtained late in labor were tested, there was a greater stimulation of PGF and less of PGE compared to early labor suggesting a preference for PGF production rather than PGE in late labor. When samples obtained from patients in dysfunctional labor were compared to normal labor, no difference on the effect of either PGE or PGF production was observed. This implies that the decreased PGF previously described in dysfunctional labor is due to an intrinsic abnormality of the fetal membranes rather than inhibition of prostaglandin production by factors mediated via the amniotic fluid.

New pregnancy and placental proteins and their possible diagnostic significance

In our laboratory a large number of, for the most part, new proteins have been detected by immunochemical methods in extracts from human term placentae: namely 3 pregnancy proteins (SP1, SP2 and SP3), around 40 soluble placental tissue proteins (PPs) and at least 11 different solubilized, apparently membrane-associated, tissue proteins. A great deal of the new proteins has been already isolated to purity and characterized. The treatise gives an overview of what is known of the physico-chemical properties and of the possible biological role of these proteins as well as of their occurrence in tissues and body fluids. It also summarizes the possible diagnostic significance of detection and measurement of these proteins on the one hand in pregnant women, on the other hand in patients with tumours and other diseases, as far as this has been already investigated.

Abnormal concentrations of prostaglandins in amniotic fluid during delayed labour in multigravid patients

Concentrations of prostaglandins E (PGE), F2 alpha (PGF), 13,14-dihydro-15-keto prostaglandin F2 alpha (PGFM), 6-keto F1 alpha and thromboxane B2 were measured by specific radioimmunoassay in samples of amniotic fluid from 22 multigravid patients during labour. Normal labour in 10 patients was associated with a significant increase of PGE, PGF and PGFM with close correlation to cervical dilatation (P less than 0.05). In the 12 patients with clinically delayed labour, in the absence of cephalopelvic disproportion, there were significantly lower PGF (P less than 0.002) and PGFM (P less than 0.05) concentrations obtained while no differences were observed in the other prostanoids measured. Administration of oxytocin to the latter group to enhance labour did not have any effect on the concentrations of prostaglandins obtained in spite of an improvement in intrauterine pressures and accelerated progress of labour.

Effects of zinc deficiency and zinc repletion during pregnancy on parturition in two strains of rats

The effects on parturition of a low zinc diet during pregnancy and of three levels of zinc repletion late in pregnancy were compared in two strains of rats, Sprague Dawley and Long Evans. Long Evans rats had a higher hematocrit and higher plasma protein levels than did Sprague Dawley rats. Long Evans rats also had heavier mammary glands and tended to deliver somewhat later than the Sprague Dawley rats. Weight gains during pregnancy and weights of the liver, spleen, adrenal glands, and pups did not vary between strains. No differences were detectable in the degree of stress at parturition between the unsupplemented females of the two strains. Injection of 300, 600, or 900 microgram zinc on day 18 of pregnancy increased female weight gains, pup weight, and spleen and mammary gland weights, and decreased hematocrit level. Three females in the unsupplemented groups died about the expected time of parturition; none died in the supplemented groups. Although there were some differences between the strains, the effects of a low zinc diet and the requirement for zinc for normal parturition were the same in the two strains. An injection of 900 microgram zinc on day 18 resulted in normal parturition in both strains.

Fetal lung maturation. III. The amniotic fluid cortisol/cortisone ratio in preterm human delivery and the risk of respiratory distress syndrome

Cortisol and cortisone have been measured in amniotic fluid samples obtained within 24 hours of deliver of 50 premature infants. When expressed as cortisol/cortisone ratios, the ratio tends to rise with advancing gestational age, although statistical significance is not attained. Both cortisol concentration and the cortisol/cortisone ratio are significantly lower in the amniotic fluid of infants who develop respiratory distress syndrome than in those with mature lung function (cortisol ratio: 19.2 +/- 10.3 ng/ml vs 26.1 +/- 9.4, P less than .02; cortisol/cortisone ratio: 1.2 +/- 0.6 vs 2.0 +/- 0.8, P less than .001). These findings also hold in the subgroup of infants less than 32 weeks' gestation but not in those infants at or beyond the 32nd week. The amniotic fluid cortisone concentration is significantly lower in infants born after spontaneous labor beginning with rupture of the membranes as opposed to after contractions or bleeding (13.2 +/- 3.6 ng/ml vs 16.3 +/- 6.1, P less than .05), although the cortisol concentrations and the cortisol/cortisone ratios are not significantly different.

Placental insufficiency in relation to postterm pregnancy and fetal postmaturity. Evaluation of fetoplacental function; management of the postterm gravida

As pregnancy extends post term, incidence of placental insufficiency, fetal postmaturity (dysmaturity), and fetal perinatal death increases rapidly as a consequence of reduced respiratory and nutritive placental function. Despite a compensatory fetoplacental respiratory reserve capacity, fetal distress is observed in about one third of postterm pregnancies. On a biochemical level, placental pathophysiology in postterm-postmaturity pregnancies is not well understood. Postmaturity is correlated with increased incidence of placental lesions, fetal hypoxia-asphyxia, intrauterine growth retardation, increased perinatal death, and neonatal morbidity. Early diagnosis of fetal postmaturity is difficult because currently applied test methods allow recognition only when placental insufficiency is far progressed. Therefore, in postterm gravidas with a favorable cervix, induction of labor should be considered; in older primigravidas, in whom fetal losses may be sevenfold increased, or in multiparas with a history of obstetric complications, pregnancy may require termination by cesarean section. Pregnancy may be allowed to continue under close supervision in cases of uncertainty of duration of gestation, in gravidas carrying small babies, in young primigravidas, and in multigravidas in whom placentofetal function tests are normal. As long as fetal scalp blood sampling during labor does not show fetal acidosis, despite abnormal fetal heart rate pattern and meconium release, vaginal delivery may be attempted when deemed possible within a few hours. In parturients attention must be paid to the extent of uterine activity and type of medication; lateral positioning of the gravida and maternal oxygen breathing, facilitating fetal oxygen supply, are important features. Because during bearing-down efforts placentofetal respiratory reserves of postterm gravidas may become further compromised, immediate delivery by forceps or vacuum extraction may be considered. After delivery the umbilical cord should not be clamped immediately in order to allow increased fetal blood supply and to counteract fetal hypovolemia. Dysmature newborn infants require special care by the neonatologist.