Induction of labour with a sustained-release prostaglandin E2 vaginal pessary.

A new polymer vaginal pessary providing sustained constant release of prostaglandin E2 was administered to 66 patients before planned induction of labour. Effective ripening of the unfavourable cervix was achieved in each of 18 primigravidas, in eight of whom labour was initiated without further treatment. When the cervix was moderately favourable the need for orthodox induction of labour was obviated in 16 out of 23 primigravidas and 21 out of 23 multigravidas. This method of sustained release of prostaglandin E2 is simple and convenient and readily acceptable to the patient; it is an important step in the development of non-invasive methods of inducing labour.     

Induction of labour with prostaglandin E2 gel in cases of intrauterine fetal death.

In established intrauterine fetal death, 20 patients were treated with prostaglandin E2 gel administered extraamniotically. The results were compared with those of another group of 20 patients who had received combined treatment. In this group, one or more of the following agents had been administered :- i.v. oxytocin, 20% NaCl solution or Premarin instilled intraamniotically, introduction of a balloon catheter or Rivanol administered extraamniotically. Average induction-abortion interval for the PG group was about 12 hours while for the second group it was about 30 hours. The side effects observed were slight in both groups. The results show that administration of PG-gel can be used with advantage in fetal demise because of the relatively short induction-abortion intervals obtained, the insignificant side effects and the low dose of PG required.     

Comparison of natural and synthetic prostaglandin E2 tablets in labour induction.

A multicentre, randomized, double-blind trial compared the efficacy and safety of and tolerance to natural and synthetically produced prostaglandin E2 tablets in the induction of labour in 202 women. The compounds were similarly effective, inducing labour in approximately 66% of patients. The total dose required and the interval between induction and delivery were similar in the two groups, as were the Apgar scores at 1 and 5 minutes and the incidence of maternal and fetal side effects.     

The relationship between fetal breathing movements and prostaglandin E2 during ACTH-induced labour in sheep

We measured fetal breathing movements and fetal carotid arterial prostaglandin E concentrations during adrenocorticotrophin-induced labour in 6 pregnant sheep and in 6 control animals starting at day 127. The 6 ACTH-treated animals went into labour on average 97 h after the onset of infusion and the incidence of fetal breathing movements diminished during the last 12h before the onset of labour. There was a significant negative relationship between the incidence of fetal breathing movements and fetal carotid arterial prostaglandin E concentrations (r = -0.88; P less than 0.001) in ACTH treated animals. These data suggest a role for prostaglandin E in the diminution of fetal breathing movements prior to the onset of labour.     

Induction of labour with prostaglandin E2 gel in cases of intrauterine fetal death

In established intrauterine fetal death, 20 patients were treated with prostaglandin E₂ gel administered extraamniotically. The results were compared with those of another group of 20 patients who had received combined treatment. In this group, one or more of the following agents had been administered: - i.v. oxytocin, 20% NaCl solution or Premarin instilled intraamniotically, introduction of a balloon catheter or Rivanol administered extraamniotically. Average induction-abortion interval for the PG group was about 12 hours while for the second group it was about 30 hours. The side effects observed were slight in both groups. The results show that administration of PG-gel can be used with advantage in fetal demise because of the relatively short induction-abortion intervals obtained, the insignificant side effects and the low dose of PG required.     

Comparative study of a two dose schedule of PGE2 3 mg pessary and 1700 micrograms film for induction of labour in nulliparae with poor cervical score

Efficacy of a two dose schedule of 3 mg pessary or 1700 micrograms film of PGE2 for induction of labour was compared in nulliparae with poor cervical score. Patient characteristics in the two groups (43 in 3 mg and 40 in 1700 micrograms group) were comparable in age, period of gestation, indications for induction of labour and in their initial cervical score. The number of patients who started labour with a two dose schedule 4 hours apart were similar in each group. The improvement of cervical score, length of labour, mode of delivery and the neonatal outcome were not different in the two groups. There was no advantage of using a film preparation over that in the form of a pessary and the use of 3 mg dose did not give significantly better results compared with the 1700 micrograms dose, in terms of obstetric or neonatal outcome.     

Experience with prostaglandin F2α (free acid) for the induction of labour

Labour was induced or augmented in 115 patients by amniotomy followed by intravenously administered prostaglandin F_2α (PGF_2α). The results were compared to those obtained retrospectively from a similar number of patients, matched for age, parity, induced and augmented labour, epidural anaesthesia and induction score; in whom labour had been induced by amniotomy followed by intravenous oxytocin titration. Both regimes were very effective, but there was a higher incidence of side effects in the patients receiving oxytocin. There was one maternal death associated with Prostaglandin infusion. Labour was also induced in a further group of 50 patients by amniotomy followed by oral PGF_2α (free acid). 42 patients (84%) were successfully induced. Vomiting and diarrhoea occurred in 22 patients (45%).     

Comparative study of oestradiol and prostaglandin E2 vaginal gel for ripening the unfavourable cervix before induction of labour.

Oestradiol 150 mg and prostaglandin E2 (PGE2) 4 mg suspended in viscous gel and applied intravaginally were compared with regard to ripening the unfavourable cervix of patients randomly allocated to two study groups. In primigravidae no significant difference was observed in the efficacy of the two substances. Some multiparous patients, however, had considerably more uterine sensitivity to PGE2 quickly developed decelerative cardiotocographic tracings after insertion of the gel. In the group given oestradiol there was a significant absence of uterine activity after gel application. The findings suggest that oestradiol applied vaginally is a safe, comfortable, cheap, and equally effective alternative to PGE2 for ripening the cervix, without the disadvantages of uterine stimulation frequently encountered with PGE2.     

Chlorophyll fluorescence induction and relaxation system for the continuous monitoring of photosynthetic capacity in photobioreactors

The development of high‐performance photobioreactors equipped with automatic systems for non‐invasive real‐time monitoring of cultivation conditions and photosynthetic parameters is a challenge in algae biotechnology. Therefore, we developed a chlorophyll (Chl) fluorescence measuring system for the online recording of the light‐induced fluorescence rise and the dark relaxation of the flash‐induced fluorescence yield (Qa^? ? re‐oxidation kinetics) in photobioreactors. This system provides automatic measurements in a broad range of Chl concentrations at high frequency of gas‐tight sampling, and advanced data analysis. The performance of this new technique was tested on the green microalgae Chlamydomonas reinhardtii subjected to a sulfur deficiency stress and to long‐term dark anaerobic conditions. More than thousand fluorescence kinetic curves were recorded and analyzed during aerobic and anaerobic stages of incubation. Lifetime and amplitude values of kinetic components were determined, and their dynamics plotted on heatmaps. Out of these data, stress‐sensitive kinetic parameters were specified. This implemented apparatus can therefore be useful for the continuous real‐time monitoring of algal photosynthesis in photobioreactors.     

Uterine and fetal asphyxia monitoring in parturient sows treated with oxytocin

Oxytocin is used to induce and control parturition, nevertheless, the increase of uterine contractions decreases blood flow and gaseous exchange through the womb predisposing to intra-partum mortality. The objective of the present study was to evaluate the effect of oxytocin on myometrial activity, fetal intrauterine hypoxia and postnatal asphyxia in sows during farrowing. Hybrid (n = 120) sows approaching the time of farrowing were randomly assigned in two groups of 60 animals each. Group I (G(1): control) was treated IM with saline solution and Group II (G(2)) was injected IM with oxytocin (1IU/6kg LW) as a single dose at birth of the first piglet. Both average number of myometrial contractions and intensity in G(2) were greater (P < 0.01) as compared with G(1). The mean of intra-partum stillbirths (IPS's) and those where fetal cardiac frequency (FCF) or heart beats, could not be detected after birth, were greater (P < 0.01) in G(2) as compared with G(1). The average decelerations of FCF known as dips II, which indicate severe hypoxia, was greater in G(2) (P < 0.01) as compared with that of G(1). There was a greater (P < 0.01) number of intra-partum stillbirths, stained with severe meconium in G(2) when compared with G(1). Oxytocin treatment increased (P < 0.01) the number of pigs born alive with ruptured umbilical cords and those with different grades of meconium staining on their skin. It was concluded that administration of oxytocin at the onset of parturition increased the myometrial activity, decreased fetal cardiac frequency, predisposed the rupture of umbilical cords and the degree of meconium staining, and increased intra-partum mortality.     

Microdevice with integrated dialysis probe and biosensor array for continuous multi-analyte monitoring

The simultaneous on-line determination of glucose and lactate using a microdevice that consisted of a dialysis sampling system incorporated to the flow-through cell of a microfabricated biosensor array is presented. The fluidic connections between the different device's components were realized by subsequent processing of stacked dry resist layers on a plastic support that provided also the means for electric connections. The performance of the device was evaluated in vitro. The cross-talk effect on the downstream sensor was investigated and found to be negligible. Recoveries of over 95% for both analytes were achieved when flow rates of the perfusion fluid 相似文献   

Toward real-time continuous brain glucose and oxygen monitoring with a smart catheter

Oxygen and glucose biosensors have been designed, fabricated, characterized and optimized for real-time continuous monitoring on a new smart catheter for use in patients with traumatic brain injury (TBI). Oxygen sensors with three-electrode configuration were designed to achieve zero net oxygen consumption. Glucose sensors were based on the use of platinum nanoparticle-enhanced electrodes that were modified with polycation and glucose oxidase immobilized by chitosan matrix. An iridium oxide electrode was developed to work as a biocompatible reference electrode with enhanced durability and stability in the biological solutions. A study of the effect of temperature on oxygen sensor performance, and both temperature and oxygen effects on glucose sensor performance were accomplished to enhance their operative stability and provide useful information for in vivo applications. A new methodology for automatic correction of the temperature and oxygen dependence of biosensor outputs is demonstrated through programmed LabView™ software. In vitro experiments in both physiological and pathophysiological ranges (oxygen: 0–60 mmHg; glucose: 0.1–10 mM; temperature: 25–40 °C) with clinical samples of cerebrospinal fluid obtained from TBI patients have demonstrated stable measurements with enhanced accuracy, indicating the feasibility of the sensors for a real-time continuous in vivo monitoring.     

Effects of oestrus induction with progestagens or prostaglandin analogues on ovarian and pituitary function in sheep

The aim of the current study was to determine possible differences in ovarian and pituitary features explaining lower fertility rates in sheep with oestrus induced with intravaginal progestagens or prostaglandin analogues (group FGA and PGF, n=8 in both) when compared to a control group (group C, n=8). The growth profiles and the mean individual sizes of preovulatory follicles were similar between groups; however, the number of preovulatory follicles per ewe and, consequently, the number of ovulations were higher in groups FGA and PGF (2.3±0.3 and 2.0±0.1, respectively) than in group C (1.4±0.1, P<0.05). However, plasma oestradiol concentrations were similar between groups suggesting a defective function in some preovulatory follicles of groups FGA and PGF. In group FGA, the basal LH levels during the follicular phase were lower (0.21±0.0 ng/mL, P<0.005) than in groups C (0.41±0.1 ng/mL) and PGF (0.55±0.1 ng/mL); the onset of preovulatory discharge being later (21.0±2.3h vs. 12.8±1.5 in C and 14.5±1.5 in PGF; P<0.05 for both). Finally, luteal activity was also found to be affected in group FGA; the rate of progesterone secretion per total luteal tissue was lower (range: 0.46-0.65 ng/mL/cm(2)) than in ewes treated with cloprostenol (2.1-3.3 ng/mL/cm(2)) and control sheep (2.0-3.4 ng/mL/cm(2)).     

Ultrasonographic appearance of the conceptus, fetal heart rate and profiles of pregnancy-associated glycoproteins (PAG) and prostaglandin F2alpha-metabolite (PGF2alpha-metabolite) after induction of fetal death with aglepristone during early gestation in cattle

A higher incidence of fetal losses, especially after the use of artificial reproduction techniques, asks for more intensive monitoring of bovine pregnancies. In this study, a model for fetal death (FD) was created by administering the antiprogesterone aglepristone twice, at Day 47 and 48 of gestation (n=5). Control heifers received the solvent (n=5). The temporal relationships between changes in ultrasonographic appearance of fetal fluids and membranes, fetal heart rate (FHR) and peripheral plasma levels of pregnancy-associated glycoprotein (PAG) and PGF2alpha-metabolite as determined by radioimmunoassay associated with FD were monitored at eight hour intervals around treatment. For the analysis of plasma levels the period under study was divided into five epochs (T1: before injection of aglepristone/solvent; T2: from first to second injection; T3: from second injection to FD; T4: from diagnosis of FD to 56 h later; T5: from 56 h to 104 h after diagnosis of FD). Control heifers produced healthy calves at term, but in treated heifers, FD occurred on average at 58 (range 48-80) h after first injection of aglepristone. Fetal death was always preceded by a visible reduction of the amount of allantoic fluid and by segregation of the allantochorionic membrane from the endometrium. FHR remained rather constant in both groups, but a (non-significant) drop in FHR around 8h before FD was diagnosed in four of five treated animals. All fetuses were expulsed after FD. Levels of PAG remained constant or even slightly increased in controls, but decreased in treated animals from T2 onward: levels during T4 and T5 significantly differed from those during T1 and from values in controls during T4 and T5 (P<0.01). PGF2alpha-metabolite levels did not change in the controls, but in the treated group they were significantly higher during T3 when compared to T1 (P<0.05). After this increase, a sharp decrease in PGF2alpha-metabolite level occurred, reaching a significantly lower level at T5 when compared to control animals (P=0.01). It is concluded, that FD induced by aglepristone is preceded by ultrasonographic visible changes in fetal membranes and fluids and a rise in PGF2alpha-metabolite and is followed by a drop in PAG and PGF2alpha-metabolite.     

Follicle and systemic hormone interrelationships during induction of luteinized unruptured follicles with a prostaglandin inhibitor in mares

The objective was to determine differences in follicle and reproductive hormone characteristics in mares with ovulatory and flunixin meglumine (FM)-induced anovulatory cycles. Estrous mares were given 1500 IU hCG when the follicle was ≥ 32 mm (0 h). In Experiment 1, control mares (n = 7) were not treated further. The remaining mares (n = 11) were given 1.7 mg/kg FM i.v. twice daily, from 0 to 36 h after hCG treatment. Blood samples and ultrasonographic examinations were performed every 12 h. All control mares ovulated normally between 36 and 48 h. In contrast, eight of 11 FM mares did not ovulate, but developed luteinized unruptured follicles (LUFs). Three FM-treated mares did not develop conventional LUFs. Plasma progesterone concentrations were lower (P < 0.05) in LUF mares at 96, 120, and 216 h than in controls, whereas plasma LH concentrations were higher (P < 0.05) between 108 and 120 h in LUF mares than in controls. Plasma concentrations of PGFM and estradiol did not differ significantly between groups. In Experiment 2, the three mares that did not develop LUFs were treated, during the consecutive cycle, with the same dose of FM but with increased frequency at zero, 12, 24, 30, 36, and 48 h after hCG. One mare formed a LUF, whereas the other two did not. These two mares had lower LH concentrations than LUF or control mares in the two consecutive cycles. In conclusion, systemic treatment with FM blocked ovulation in 73% of treated mares. Mares with LUFs had lower progesterone and higher LH concentrations than control mares.     

Serum-dependent induction of plasminogen activator in human fibroblasts by catecholamines and comparison with the effects of prostaglandin E1

Human foreskin fibroblasts produce the protease plasminogen activator, as shown by the ability of cell extracts to lyse 125I-labelled fibrin in the presence of plasminogen. Cellular plasminogen activator was stimulated up to 3-fold by 0.01-10 microM epinephrine, norepinephrine, or isoproterenol. Increases in plasminogen activator were slow in onset (24 h) and long-lived (greater than 48 h), and were abolished by 10 micrograms/ml of cycloheximide or 1 microgram/ml of actinomycin D, suggesting de novo synthesis of the protease. Stimulation of plasminogen activator by catecholamines was inhibited by 10 microM propranolol but not by 10 microM phentolamine, suggesting the involvement of beta-adrenergic receptors. Catecholamines stimulated plasminogen activator only in the presence of fetal bovine serum; under serum-free conditions they were inhibitory. Serum did not appear to alter the uptake and metabolism of epinephrine during incubation with fibroblasts. The ability of fetal bovine serum to support the induction of plasminogen activator by either 1 microM epinephrine or 3 microM prostaglandin E1 was maintained following dialysis but lost on heating (70 degrees C, 10 min) or acidification (pH 2.5). Human and calf sera supported the stimulatory effects of prostaglandin E1 but not of epinephrine. These results indicate that serum may influence the synthesis of plasminogen activator in cultured cells by modifying their response to vasoactive hormones.     

Altered fetal pituitary-adrenal function in the ovine fetus treated with RU486 and meloxicam, an inhibitor of prostaglandin synthase-II

Term and preterm labor are associated with increased fetal hypothalamic-pituitary-adrenal (HPA) activation and synthesis of prostaglandins (PGs) generated through the increased expression of prostaglandin H synthase-II (PGHS-II) in the placenta. Inhibition of PGHS-II has been advocated as a means of producing uterine tocolysis, but the effects of such treatment on fetal endocrine functions have not been thoroughly examined. Because PGE(2) is known to activate the fetal HPA axis, we hypothesized that administration of meloxicam, a PGHS-II inhibitor, to sheep in induced labor would suppress fetal HPA function. Chronically catheterized pregnant ewes were treated with RU486, a progesterone receptor antagonist, to produce active labor, and then treated with either high-maintenance-dose meloxicam, graded-maintenance-dose meloxicam, or a saline infusion. Maternal uterine contraction frequency increased 24 h after the RU486 injection and the animals were in active labor by 48 +/- 4 h. RU486 injection led to increased concentrations of PGE(2), ACTH, and cortisol in the fetal circulation, and increased concentrations of 13,14 dihydro 15-ketoprostaglandin F(2 alpha) (PGFM) in the maternal circulation. Uterine activity was inhibited within 12 h of beginning meloxicam infusion at both infusion regimes. During meloxicam infusion there were significant decreases in fetal plasma PGE(2), ACTH, and cortisol concentrations, and PGFM concentrations in maternal plasma. In control animals, frequency of uterine contractions, maternal plasma PGFM, fetal plasma PGE(2), ACTH, and cortisol concentrations increased after RU486 administration, and continued to rise during saline infusion until delivery occurred. We conclude that RU486-provoked labor in sheep is associated with activation of fetal HPA function, and that this is attenuated during meloxicam treatment to a level considered compatible with pregnancy maintenance.