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Biomedical subjects

M Pajntar

Publications and source records attributed to M Pajntar.

At least 19 recordsLinked to original sources
PubMed2001

Uterine electrical activity as predictor of preterm birth in women with preterm contractions.

OBJECTIVE: To estimate the risk of preterm birth in women admitted to the tertiary maternity hospital for preterm contractions by measuring electrical uterine activity. STUDY DESIGN: The study included 47 patients with contractions between the 25th and 35th week of gestation and additional risk factors for preterm delivery. Uterine electrical activity was recorded using bipolar electrodes placed on the abdominal surface. A logistic model with the electromyographic and obstetric data was built, preterm delivery before 37th week of gestation being the outcome measure. RESULTS: Seventeen patients (36%) delivered before term. Logistic regression model suggested only the intensity of electrical uterine activity and woman's body weight to be significant predictors of preterm delivery, with high values related to preterm birth. They predict preterm delivery with the sensitivity of 47% and specificity of 90%. CONCLUSION: We propose uterine EMG as a simple, non-invasive means to estimate the risk of preterm birth in a high-risk population with multiple risk factors present.

Electromyography↗
PubMed2001

Contribution of cervical smooth muscle activity to the duration of latent and active phases of labour.

OBJECTIVE: To identify the effect of cervical muscle activity as an additional factor influencing the duration of the latent and active phase of labour. DESIGN: Prospective observational study. SETTING: The Ljubljana Maternity Hospital. PARTICIPANTS: Fifty healthy nulliparous women requiring induction of labour having relatively unripe cervices. METHODS: At the onset of labour an open-ended catheter was inserted to measure intrauterine pressure during the latent and active phase of labour. Electromyographic activity of the cervix was registered by two bipolar spiral needle electrodes placed in the transverse direction on the proximal part of the cervix in the vagina. The mean intensity of distinctive peaks in an electromyographic spectrogram were calculated in the time/frequency domain. Multiple linear regression was used to find factors affecting the duration of the latent and active phase of labour. MAIN OUTCOME MEASURES: Duration of the latent and active phase of labour. RESULTS: Eleven independent variables explained 64% of the variance of the latent phase duration, the most important being the effacement and consistency of the cervix, and intensity of electromyographic signals. For the duration of the active phase the same variables explained 36% of the variance; the most important variables were mean duration of uterine contractions, mean maximum intensity of uterine contractions and the newborn's head circumference. CONCLUSIONS: The cervical smooth muscle activity, expressed as an electromyographic signal, contributes to the duration of the latent phase but not to the duration of the active phase. However, frequent cervical contractions are not associated with a longer latent phase.

Birth Weight↗
PubMed1999

Active contractions of the cervix in the latent phase of labour.

OBJECTIVE: To study the activity of the human uterine cervix at the onset of labour and further characterise cervical asynchronous electromyographic (EMG) activity in the latent phase. DESIGN: Prospective observational study. SETTING AND PARTICIPANTS: Clinical hospital in Ljubljana. PARTICIPANTS: Forty-seven healthy nulliparous women with relatively unripe cervices requiring induction of labour. METHODS: Simultaneous registration of a cervical EMG and of the intrauterine pressure at the very early stage of labour; subsequent EMG signal processing to determine its time, amplitude and frequency parameters. MAIN OUTCOME MEASURES: Simultaneous comparison of the cervical EMG and the mechanical activity of the uterine corpus to deduce electrical properties of the cervical smooth muscle tissue and its activity. RESULTS: EMG bursts, asynchronous with the contractions of the uterine corpus, were registered in 20 out of 47 women. In 14 women bursts appeared independent of uterine corpus contractions and in six they followed the peak of contractions. The bursts had low average median frequency (0.3 Hz). In seven women bursts were superimposed onto a background EMG (median frequency = 1.2 Hz). CONCLUSIONS: Bursts in the cervical EMG may appear asynchronously with the uterine contractions. Bursts not related to contractions suggest active and independent cervical muscle activity. The bursts which follow contractions may be an active response of the cervical musculature to passive stretching during a contraction. The EMG frequency content suggests two different contraction mechanisms or a different origin of the EMG in the cervix.

Amnion↗
PubMed1999

Electromyographic activity of the uterus above the placental implantation site.

The aim of this study was to evaluate the electromyographic (EMG) activity of the uterus concerning the placental implantation site. In a clinical trial, 55 pregnant women in the last trimester of pregnancy were enrolled. They were divided into two major groups: 25 women had placental implantation site on the anterior and 30 women on the posterior uterine wall. With regard to the presence/nonpresence of contractions, each group was further divided into two subgroups. Uterine EMG activity was recorded by electrodes placed on the abdominal wall. All signals were transferred through a series of amplifiers. Amplified and filtered EMG signals were digitized and written on a hard disk, simultaneously with the signals of external tocodynamometry. From the 30-min EMG recording, we calculated the average root mean square (RMS) and the average median frequency (MF) of the signal. A significant difference of the abdominal EMG activity concerning the placental implantation site was found only in pregnant women with contractions. The RMS was significantly lower in the placental implantation site on the anterior uterine wall, whereas the MF was significantly higher. It can be concluded that the placental implantation site influences the uterine EMG activity registered through the abdominal wall, especially when registered above the placental implantation site.

Electromyography↗
PubMed1998

Activity of smooth muscles in human cervix and uterus.

OBJECTIVE: To find the similarities and dissimilarities between the activity of the human smooth muscles in the cervix and in the uterine corpus at the onset of induced labour. STUDY DESIGN: Electromyographic activity was measured in 14 primiparous women after amniotomy. The data were sampled and stored digitally in real time. For statistical analysis, the first 20 min of recordings following amniotomy were analyzed. The ratio between the mean activity at a given time and the mean activity over the whole 20 min was used for the comparison between the cervical and uterine activity. RESULTS: The analysis of correlation showed that the electromyographic activity in the cervix differed from that in the uterine corpus in the majority of the enrolled cases. CONCLUSIONS: The muscular activity in the cervix is independent of that in the uterine corpus at the onset of induced labour.

Cervix Uteri↗
PubMed1997

Maternal and neonatal outcome related to delivery time following premature rupture of membranes.

OBJECTIVE: To evaluate neonatal and maternal outcomes of PROM deliveries with regard to the time elapsed since preterm rupture of membranes (PROM) to delivery. METHOD: According to the time elapsed since PROM to delivery we divided all singleton deliveries with PROM after the completed 34th week of gestation (N = 35,419), which occurred in Slovenia between 1988 and 1994, into four groups: within 12 h, within 13-24 h, within 25-48 h, and over 48 h after PROM. The analysis was focused on the management of labor, neonatal and maternal infections and perinatal hypoxia with regard to the elapsed time. The Kruskal-Wallis analysis of variance, the Pearson chi-square test, Spearman rank correlation test, and the logistic regression test were used. RESULTS: With increasing time elapsed since PROM to delivery we found significantly increased incidences of induced labor, operative delivery, fetal distress, poorer fetal condition at birth, neonatal infections, and minor maternal infections. CONCLUSION: We may conclude that the best neonatal and maternal outcomes are obtained if delivery occurs within 12 h after PROM.

Delivery, Obstetric↗
PubMed1997

Rupture of the membranes and postpartum infection.

The greatest risk of preterm prelabour rupture of membranes (PPROM) is preterm delivery. According to the Perinatal Information System of Slovenia there were 5.92% preterm deliveries in 1994. We studied 809 deliveries of less than 34 weeks of gestation in the Ljubljana Maternity, from 1992 to 1994; 33.7% of these started with PPROM. Risk factors for PPROM were conization, cerclage and use of antibiotics for any reason in current pregnancy. Amnionitis and febrile illness during labour increased with longer duration of PPROM but maternal postpartum infections did not. In neonates, more cases of lower Apgar scores after 1 and 5 min and more cases of suspected sepsis were found with the increased duration of PPROM. In Slovenia, with good facilities for transport in utero and good neonatal care, after PPROM it is best to transport the pregnant women to the third level center and then wait until labour starts or to recur to prompt delivery when maternal or fetal signs so require. From 1987 to 1993 there were 159264 deliveries in gestations equal to or over 34 weeks; 20.8% started with PROM. In our observational study we found the best results when labour was induced. There are, however, many disagreements about the management of (P)PROM.

Bacterial Infections↗
PubMed1995

Electromyographic activity in cervices with very low Bishop score during labor.

OBJECTIVES: To investigate the activity of the smooth muscles in the cervix at the onset of induced labor and to further elucidate this activity in relation to uterine contractions and to the duration of the latent phase of labor, taking cervical ripeness into account. METHODS: Cervical electromyographic (EMG) activity was studied at the onset of labor induced with amniotomy and oxytocin. Bipolar measurement of cervical electrical activity was performed. The root mean square of the cervical EMG activity and the intensity of intrauterine pressure in two groups of parturients with different cervical ripeness were compared. RESULTS: The EMG activity was higher in the group with lower Bishop scores. We found a significant positive correlation between EMG activity and duration of the latent phase of labor. CONCLUSION: Smooth muscles in the human cervix are active during labor and act to some extent independently of the uterine corpus.

Amnion↗
PubMed1994

Cesarean section in breech by birth weight.

OBJECTIVE: To evaluate the effects of abdominal versus vaginal delivery in the groups of newborns with different birth weights. METHODS: 5012 single breech deliveries with birth weight over 1000 g, lethal malformations and stillbirths excluded, were enrolled in the study. The comparison of early neonatal mortality and the incidence of 12 different symptoms and signs of fetal morbidity for abdominally/vaginally delivered newborns was made within four birth-weight groups. RESULTS: In abdominal delivery we found statistically significantly lower neonatal mortality and incidence of low 5-min Apgar score in the 1000-1499-g birth-weight group; incidence of brachial plexus damage and hyperbilirubinemia due to blood resorption in the 2500-3799-g birth-weight group. In vaginal delivery we found statistically significantly lower incidence of low 1- and 5-min Apgar score, light and moderate hypoxia and RDS in the 1500-2499-g birth-weight group; low 1-min Apgar score and light hypoxia in the 2500-3799-g birth-weight group. CONCLUSION: The effects of abdominal delivery on newborn in breech are in many aspects poorer than in vaginal delivery. In our opinion the actual incidence (36%) of cesarean section could be decreased, especially in cases with expected birth weight over 1500 g.

Apgar Score↗
PubMed1993

The effect of pethidine hydrochloride on the cervical muscles in the active phase of labour.

The effect of pethidine hydrochloride (PHC) on the smooth muscles of cervix was studied in the active phase of induced labour in 27 primiparous women. The Electromyographic (EMG) root mean square (RMS) which provides information about the amplitude (intensity) of muscular cervical activity, and the median frequency (MF) which represents the EMG frequency spectrum were analyzed in connection with the intensity of intra-uterine pressure (IIUP). The RMS significantly decreases after the application of PHC, while the IIUP significantly increases. The effect of the applied drug disappears in one hour's time. The MF values increase insignificantly after the application and change in the opposite direction to the change of MSR. The change RMS, MF and IIUP values do not correlate with the duration of the active phase of labour.

Cervix Uteri↗
PubMed1992

Effect of spasmoanalgetic Dolantin on the electromyographic activity of the cervix during labour.

The influence of spasmoanalgetic Dolantin on electrical activity of the smooth musculature of the cervix during labour was studied in 50 primiparous women after induction of labour. The highest electrical activity was measured at the time of uterine contraction (AC) and between contractions (BC). The basic pattern of Dolantin-produced changes in muscular contractions in the cervix observed via EMG activity is that of the EMG activity diminishing with contractions of the uterine corpus and even more so in the period between contractions. Dolantin administered during the latent phase of induced labour did not accelerate cervical dilatation either in the latent or in the active phase of amniotomy- and Oxytocin-induced labour.

Cervix Uteri↗
PubMed1991

Changes in electromyographic activity of the cervix after stimulation of labour with oxytocin.

The electrical activity of the cervix can be measured during labour. The influence of oxytocin on electromyographic (EMG) activity of the cervical musculature was studied in 80 primiparous women after induction of labor. The highest electrical activity registered at the time of uterine contraction and between two contractions was used for analysis. The basic pattern of oxytocin-produced changes in muscular contractions in the cervix observed via EMG activity is that of the activity increasing with contractions of the uterine corpus and diminishing between contractions. The effect of oxytocin on cervical musculature is different in ripe and unripe cervices.

Cervix Uteri↗
PubMed1988

Longitudinally and circularly measured EMG activity in the human uterine cervix during labour.

The role of the smooth cervical muscle has not yet been sufficiently explored. For that reason cervical EMG was measured during induced labour of several primiparas and multiparas. Three spiral electrodes were placed on the cervix in order to measure the EMG in the longitudinal and circular direction referred to the cervical axis. A quantitative analysis of changes in the amplitude and frequency of the EMG signals was performed by means of the spectral method. It was found that the EMG measured from the two leads differed in unripe cervices in the latent phase of labour. The differences are illustrated by two cases. Some possible explanations for the different activity are discussed.

Cervix Uteri↗
PubMed1987

Electromyographic observations on the human cervix during labor.

The activity of smooth muscles in the cervix is one of the relevant factors for its dilatation during labor, but in humans it has not yet been sufficiently studied. Muscular activity may be observed by measuring electromyographic phenomena. In 60 parturient women of different parity and with various degrees of cervical ripeness at the onset of labor, the cervical electromyographic activity was measured through the entire course of labor in synchronization with uterine pressure measurements and also in 30 cases in synchronization with measurements of the uterine corpus electromyographic activity. The conditions necessary for successful measurements are described. The intensity of the cervical electromyographic activity was found to decrease with the level of cervical ripeness and with parity. When measured in the longitudinal direction, the cervical electromyographic activity resembled that of the uterine corpus, but when picked up from the circular lead, in a few cases of unripe cervices it differed from the electromyographic activity of the uterine corpus.

Cervix Uteri↗
PubMed1981

Stress and radiation carcinogenesis in mice.

In the present experiment irritation consisting of a combination of an optic signal followed by a mild electroshock administered at regular intervals was started in 2 groups of animals at the age of 3 months. At 4 months of age, one of the irritated and one of the nonirritated groups were exposed to whole-body gamma irradiation at 20 daily doses of 0.5 Gy (50 rad(, 1.4 Gy/min (140 rad/min), while the other 2 groups were sham-irradiated. The animals were autopsied and the specimens were microscopically studied for the presence of malignant tumors. Malignant tumors involving particularly the testes and lungs and leukosis were found in 29% of males, whereas in females the tumor incidence with mammary, pulmonary and ovarian involvement and leukosis was 39%. The irradiation decreased the minimum latency time in the irritated males and both female groups. In males, the irritation lowered the cumulative prevalence of malignant tumors, a significant decrease being noted at the age of 15 months. In females, it was increased, with a significant rise observed to occur at the end of the experiment. The opposite effects of irritation on the radiation carcinogenesis in males and females can be attributed to the irradiation-induced specific alterations of the gonads in females and, in part, to a longer survival time observed in the irradiated females.

Animals↗
PubMed1979

Stress and Ehrlich ascites tumor in mouse.

The aim of the study was to investigate the interaction of the psychosomatic stress and the Ehrlich ascites tumor (EAT) growth in mice. The stressor consisted of combination of a light signal followed by a mild electric shock. The first experiment was performed on CBA mice irritated for 0, 2 and 4 weeks respectively, prior to intraperitoneal transplantation of the EAT. In the second study, mice of BALBc strain were used. Stress was applied 4 weeks before the tumor transplantation and continued throught the experiment. Both the irritated and the nonirritated animals were subjected to either intraperitoneal or subcutaneous inoculation of the EAT. In both experiments, mice were left to live until their spontaneous death. In the first experiment, after a 2-week irritation the experimental animals showed a significantly longer survival time as compared to the controls. Longer or shorter duration of the irritation had no significant effect on the results obtained. Results yielded by the second experiment showed no significant difference in the time of survival of the irritated and nonirritated animals after the i. p. transplantation, whereas after the s. c. inoculation of the EAT, the irritation significantly increased the survival period. The EAT in irritated mice was observed to have invaded the vitals later and less frequently than in the nonirritated animals. Quantitative histological analysis of some endocrine and lymphatic organs revealed signs of stress in the experimental animals. The EAT transplant, per se, had a stressogenic effect too.

Animals↗