Changes In Uterine Contractions Research Articles

Cooperation of aquaporin 5 and the adrenergic system in the initiation of birth in rat model

Aquaporins (AQPs) are involved in the process of implantation, regulate myometrial contractions and cervical ripening, and maintain appropriate placental functioning. The molecular mechanism of these functions is not fully understood. Our study aimed to investigate the physiological significance of AQP5 during pregnancy and to determine the cooperation between the adrenergic system and the AQP5 in uterine contraction in the late-pregnant rat uterus.After administering AQP5 siRNA intraperitoneally to Sprague-Dawley rats, the length of the gestational period was determined and the changes in uterine contractions were measured in an isolated organ bath system. Pharmacological influence on AQP5 expression and uterine contraction was investigated by treatment with terbutaline (10 mg/kg, subcutaneously) and doxazosin (5 mg/kg, orally) in vivo; and mercuric chloride (HgCl2), in vitro. Moreover, the levels of cAMP response element binding protein (CREB) were measured in the uterus by an ELISA kit.The gestational period became shorter, AQP5 expression significantly decreased and rat uterus contraction increased after AQP5 siRNA treatment compared to the control. Treatment with terbutaline significantly increased AQP5 mRNA and protein expression after 30 min and continuously reduced it until 90 min, whereas doxazosin treatment did not significantly alter AQP5 expression. Treatment with the AQP5 antagonist HgCl2 increased spontaneous uterus contraction and decreased norepinephrine-induced uterus contraction with decreasing AQP5 expression in pregnant rat uterus. Moreover, the tocolytic effect through the adrenergic system was amplified in the presence of an AQP5 antagonist, presumably via the changes in cAMP level.In conclusion, our findings elucidate the collaborative role of aquaporin 5 (AQP5) and adrenergic systems in the regulation of uterine contractions in late-pregnant rats. Our findings suggest this may be a good starting point for developing a new tocolytic therapy.

Empirical Mode Decomposition Based Measures for Investigating the Progression of Pregnancy from Uterine EMG.

The objective of this study is to analyze the uterine electromyography (uEMG) signals to study the progression of pregnancy under term condition (gestational age > 36 weeks) using EMD-based time-frequency features. uEMG signals are obtained from the multiple public datasets during two conditions, namely T1 (acquired < 26 gestational weeks) and T2 (acquired ≥ 26 gestational weeks). The considered signals are preprocessed. Empirical mode decomposition is applied to decompose the signals and time-frequency features, such as median frequency (MDF), mean frequency (MNF), peak frequency and peak magnitude, are extracted from each intrinsic mode functions and statistically analyzed. The results depict that the obtained time-frequency features are able to distinguish between T1 and T2 conditions. The extracted features, namely MNF and MDF, are observed to decrease from T1 to T2 conditions. These features are found to have higher effect size, confirming the better differentiation between T1 and T2 conditions. It appears that EMD-based time-frequency features can aid in studying the evolving changes in uterine contractions towards labor.

Effect of dexmedetomidine on oxytocin-induced uterine contraction during optimal caesarean section anaesthesia.

Numerous drugs are used during caesarean sections to provide regional and general anaesthesia. Dexmedetomidine has been used in some recent obstetric trials, but there are concerns about postpartum changes in uterine contractions. This study evaluated the effect of dexmedetomidine on oxytocin-induced uterine contractions in women undergoing caesarean section. Sixty women undergoing caesarean section in Lianyungang Second People's Hospital were randomly assigned to dexmedetomidine (group D, n = 30) or saline (group C, n = 30) groups. Equal volumes of saline or dexmedetomidine were administered intravenously (IV). During the intraoperative delivery of the foetus and placenta, oxytocin was administered to promote contractions. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were compared. The Ramsay scale was used to assess sedation, while the Tsai and Chu methods assessed shivering. Adverse intraoperative events were observed. All variables fluctuated significantly after anaesthesia onset in both groups but were most pronounced in group D. The VAS, Ramsay and shivering scores were significantly lower in group D compared to group C. During rapid IV infusion of oxytocin after foetal delivery, the incidence of nausea, vomiting, chest tightness and hypotension was significantly lower in group D than in group C.

Analysis of Preterm Pregnancies using Empirical Mode Decomposition based Fractal Features

Abstract Preterm birth (gestational age &lt; 37 weeks) is a serious pregnancy related complication that could lead to fetal morbidity and mortality. Monitoring the activity of uterus is considered to be crucial for the early diagnosis of preterm birth. Uterine Electromyography (uEMG) is a non-invasive technique that provides a quantitative measure of uterine activity from the abdominal surface. In this work, an attempt has been made to characterize preterm uEMG signals using Empirical Mode Decomposition based Detrended Fluctuation Analysis (EMD-DFA). Preterm signals with varied gestational ages are considered from an online database. EMD-DFA is applied on these signals to compute the fluctuation function. The double-logarithmic plot of fluctuation function versus scale is evaluated and Chi-square analysis is performed for identifying linear scaling regions. Five features namely shortterm exponent (Hs), long-term exponent (Hl), inflection point, short-term fractal angle (αHs) and long-term fractal angle (αHl) are extracted and analyzed. Further, Coefficient of Variation (CV) is computed to examine the variations of these features among different subjects. Results show that EMD-DFA is able to characterize the fluctuations of preterm signals. From the double-logarithmic plot, a slow variation of fluctuation function is observed with respect to scale when the time to delivery is more. This indicates the presence of rapid signal fluctuations in the early stages of pregnancy. Based on the feature values, it is observed that the signal fluctuations are more correlated and smoother as the time to delivery approaches. Among the extracted features, CV values of Hs, Hl, αHs and αHl are observed to be low indicating that these features have least inter-subject variations in preterm signals. The EMD-DFA based fractal features show the ability to detect the subtle variations in uEMG signals. As early diagnosis of preterm delivery is imperative for timely medical intervention and treatment, it appears that the proposed approach could aid in determining the changes in uterine contractions in preterm condition.

Comparison of the Effectiveness of 5 IU Oxytocin Bolus and 20 IU Infusion on Uterine Contraction and Hemodynamic Response in Caesarean Section

Uterine atonic can result in postpartum hemorrhage, gravid hysterectomy andmaternal mortality. Oxytocin is the most commonly used agent for the preventionand treatment of atonic uterine during cesarean section. However, the provision ofrapid and increasing the dose may result in hemodynamic instability, cardiovascularcollapse, and death. This study aimed to compare the effectiveness of oxytocin bolus5 IU and oxytocin infusion 20 IU to contractions of the uterus and the hemodynamicresponse in cesarean section with spinal anesthesia.An experimental study, Randomized Controlled Trial (RCT) was conducted in theoperating room Mohammad Hoesin Hospital Palembang from July to August 2016.It was obtained a 44 pregnant at term women who will do a cesarean section thatmeet the inclusion and exclusion criteria. The frequency and distribution of data aredescribed in tables and comparisons between the two groups were analyzed usingSPSS.Of the 44 pregnant women at term, 22 women in the group of oxytocin bolus 5 IUand 22 women in the group of oxytocin infusion 20 IU. By statistical analysis, therewas no significant hemodynamic changes after bolus administration of oxytocin 5 IUor oxytocin infusion 20 IU (p&gt; 0.05) and there were no significant hemodynamicdifferences between oxytocin bolus 5 IU and infusion of 20 IU oxytocin (p&gt; 0.05). Inaddition, there are significant changes in uterine contractions after bolusadministration of oxytocin 5 IU or oxytocin infusion 20 IU (p&lt; 0.05) and there weresignificant differences in uterine contraction in the 3rd minute (p = 0.006), 6thminute ( p = 0.010) and 9th minute (p = 0.008) between oxytocin bolus 5 IU andinfusion of oxytocin 20 IU.It can be concluded that there is no significant hemodynamic changes afteradministration of oxytocin 5 IU bolus and oxytocin infusion 20 IU and there aredifferences in uterine contractions significantly in the 3rd minute, 6th minute and9th minute between oxytocin bolus 5 IU and oxytocin infusion 20 IU.

Differentiation of fluctuations in uterine contractions associated with Term pregnancies using adaptive fractal features of electromyography signals

Analysis of uterine contractions using electromyography signals is gaining importance due to its capability to measure the dynamics of uterus. Uterine electromyography (uEMG) provides information on the nature of uterine contractions non-invasively. In this study, the fluctuations in uEMG signals associated with Term pregnancies are analyzed. For this, Term uEMG signals corresponding to second (T1) and third (T2) trimesters are considered. The signals are subjected to Adaptive Fractal Analysis (AFA), wherein a global trend is obtained by using overlapping windows of three orders namely, 25%, 50% and 75%. The signals are detrended and the fluctuation function is estimated. Two Hurst exponent features computed at short range (Hs) and long range (Hl) are extracted and statistically analyzed. Results show that AFA is able to characterize variations in the fluctuations of Term delivery signals. The feature values are observed to vary significantly during different weeks of gestation. It is found that features of T2 signals are higher than that of T1 signals for all the considered overlaps, indicating that T2 signals possess smoother characteristics than T1 signals. Further, coefficient of variation is observed to be low, indicating that these features are able to handle the inter-subject variations in Term signals. Therefore, it appears that the proposed approach could aid in investigation of progressive changes in uterine contractions during Term pregnancies.

Clinically relevant concentrations of dexmedetomidine may reduce oxytocin-induced myometrium contractions in pregnant rats.

BackgroundRecently, there have been some trials to use dexmedetomidine in the obstetric field but concerns regarding the drug include changes in uterine contractions after labor. We aimed to evaluate the effects of dexmedetomidine on the myometrial contractions of pregnant rats.MethodsIn a pilot study, the contraction of the myometrial strips of pregnant Sprague-Dawley rats in an organ bath with oxytocin at 1 mU/ml was assessed by adding dexmedetomidine from 10-6 to 10-2 M accumulatively every 20 min, and active tension and the number of contractions were evaluated. Then, changes in myometrial contractions were evaluated from high doses of dexmedetomidine (1.0 × 10-4 to 1.2 × 10-3 M). The effective concentrations (EC) for changes in uterine contractions were calculated using a probit model.ResultsActive tension and the number of contractions were significantly decreased at 10-3 M and 10-4 M dexmedetomidine, respectively (P < 0.05). A complete loss of contractions was seen at 10-2 M. Dexmedetomidine (1.0 × 10-4 to 1.2 × 10-3 M) decreased active tension and the number of contractions in a concentration-dependent manner. The EC95 of dexmedetomidine for inhibiting active tension and the number of contractions was 5.16 × 10-2 M and 2.55 × 10-5 M, respectively.ConclusionsActive tension of the myometrium showed a significant decrease at concentrations of dexmedetomidine higher than 10-3 M. Thus, clinical concentrations of dexmedetomidine may inhibit uterine contractions. Further research is needed for the safe use of dexmedetomidine in the obstetrics field.

Determination of Dichlorvos Effect on Uterine Contractility Using Wavelet Transform

Purpose: The use of organic synthetic pesticides has increased heavily in recent years and organophosphate insecticides constitute 20–38% of the total pesticides used worldwide. Dichlorvos, an organic phosphate insecticide, is widely used for the control of the agricultural, industrial and domestic pest in most of the agricultural countries like Turkey and it is known that many chemical toxins are capable of producing changes in uterine contractions. In this study, the effects of different doses of dichlorvos on isolated uterus muscle contractions are evaluated.Methods: Wavelet scalogram analysis is preferred in the study because of its simultaneous time, frequency and energy screening capability.Results: Obtained results show that 50 μM and 100 μM doses of DDVP significantly decreased the energy of contractions.Conclusions: The study is important in that it shows toxic effects of DDVP on uterus which is responsible for reproductive function of mammalians and that it draws attention to an important public health problem. Furthermore, this is the first study showing that the wavelet transform can be readily utilized to determine the effects of insecticides and similar chemicals on the uterus spontaneous activity.

The Puerperium of the Cow: A Study of Uterine Motility

Summary Clinical observations were made during the puerperium of 107 attested cows and heifers. The motility of the involuting uterus was studied in 50 cases and the action of drugs on uterine contractions in a further 22. . The normal. patterns of uterine motility during the first 1 2 hours-after expulsion of the foetus and during the later periods are described. In seven cases in which the puerperium was abnormal, uterine contractions are compared with the normal pattern. No significant changes in uterine contractions was observed during periods when the cow was allowed to lick the calf or during suckling. The actions of pituitarv extract, stilboestrol and. other drugs on uterine motility during the normal and abnormal puerperium are described. Evidence is advanced to support the view that retention of the foetal membranes is associated with reduced uterine motility within 24 hours after calving.