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Biomedical subjects

B A Nilsson

Publications and source records attributed to B A Nilsson.

At least 19 recordsLinked to original sources
PubMed1989

Effect of nipple stimulation on uterine activity and on plasma levels of oxytocin in full term, healthy, pregnant women.

The effect of nipple stimulation on uterine activity, foetal heart rate and plasma oxytocin level in healthy full term pregnant women was studied. Ten women in weeks 38-39 of pregnancy stimulated their nipples for 30 min. Nine of the ten experienced uterine contractions. One woman showed signs uterine hyperactivity (frequent contractions) and foetal heart rate decelerations. Blood samples were drawn at 15 s intervals during 5-6 contractions and oxytocin levels were measured with radioimmunoassay. Oxytocin levels rose significantly during the nipple stimulation and short bursts of oxytocin were recorded during contractions. Nipple stimulation has been used to induce labour and our data may suggest that oxytocin released in response to such stimulation is responsible for the contractions induced.

Adult↗
PubMed1988

Evaluation of three simple physiologic tests as predictors of pregnancy-induced hypertension. A pilot study.

In order to try to find a method for predicting pregnancy-induced hypertension (PIH), the roll-over test, isometric handgrip test and cold pressor test were performed on 40 healthy pregnant women in their 29th to 31st week of pregnancy. All these three tests proved positive (rise in diastolic pressure of at least 20 mmHg) in more than 50% of the subjects. None of the women in the study developed PIH (blood pressure 140/90 or more on at least two consecutive occasions). These results indicate that none of these simple physiologic tests is of use as a predictor of PIH.

Adolescent↗
PubMed1988

Effect of exercise on catecholamines and plasma renin activity in pregnant women.

Strenuous muscular exercise is known to induce increases in plasma values of adrenalin (A) and noradrenaline (NA) and a twofold increase in plasma renin activity (PRA) in healthy men and women. The effect in pregnant women is not known. In 36 pregnant women, systolic blood pressure and plasma levels of PRA, A and NA were determined at rest, during an orthostatic test and during submaximal leg exercise on a bicycle ergometer. Eight of these women were re-examined after delivery and served as a non-pregnant control group. The pregnant women had a significantly greater increase in systolic blood pressure than the non-pregnant subjects. PRA showed a sevenfold increase during pregnancy, but exercise caused no further change in plasma values. As expected, the non-pregnant PRA values doubled during exercise. Resting values of A and NA were not altered by pregnancy. Near-maximal exercise caused a significant rise in A and NA, both in pregnant and in non-pregnant women. The results indicate that there is no activation of the sympathetic nervous system either at rest or during strenuous exercise in pregnancy and that the sensitivity of the circulatory system seems to be well adjusted to the increased activity of the renin angiotensin system during pregnancy.

Adolescent↗
PubMed1986

Reduced platelet MAO activity during pregnancy.

The kinetics and thermolability of platelet MAO were studied in twenty-three women during and after pregnancy. The maximal velocity of the enzyme (Vmax) was significantly reduced during pregnancy, whereas the apparent, Michaelis constant (Km) was unaltered. The initial velocity of the enzyme (vo) was significantly lowered during the pregnant period compared to after delivery. However, when the enzyme activity was determined in the presence of autologous plasma, no significant difference in deaminating activity between the two occasions could be detected. This was caused by a significantly increased activating capacity of the plasma collected during the pregnant period, expressed as the ratio of MAO activity determined in the presence and absence of plasma. Moreover, pregnant women showed an increased thermal stability of the platelet MAO compared to non-pregnant women.

Adolescent↗
PubMed1979

The effect of local anaesthetic agents on the contractility of human myometrium in late pregnancy. An in vitro study.

Four local anaesthetic agents, lidocaine, prilocaine, bupivacaine and etidocaine with and without adrenaline, were tested regarding their influence on the contraction amplitude, tone and frequency of contractions of human myometrium in vitro. All four drugs had a dose-related inhibitory effect on the amplitude. This was enhanced by adrenaline. The two short-acting and the two long-acting agents were tested in equianalgesic doses in a crossover test. Lidocaine and etidocaine had a significantly greater inhibitory effect on the spontaneous myometrial contractions than prilocaine and bupivacaine. With all drugs, except etidocaine, the tone increased with increasing drug concentrations in the bath. The changes in frequency were inconsistent. Based on the concentrations required to produce 50% inhibition, lidocaine, bupivacaine and etidocaine were, respectively, 1.3, 6.5 and 8.3 times more potent than prilocaine; the corresponding figures for the anaesthetic effect on isolated nerves are reported to be 1.5, 5.3, and 5.3. The inhibitory effect of etidocaine declined with time, in contrast to the other local anaesthetic agents tested.

Anesthetics, Local↗
PubMed1979

Effect of segmental epidural block on the course of labour and the condition of the infant during the neonatal period.

Epidural block for vaginal delivery was given to 242 women during a 6-month period. Of these, 178 with a spontaneous start of labour and vaginal delivery were studied with respect to the effect of epidural block with bupivacaine-adrenaline on the course of labour and the condition of the infant in women with normal uterine activity and women with primary uterine inertia treated with oxytocin infusion. On average, the 178 women had already had a longer course of labour before the block was applied than women in control groups. The block per se had only a slight effect on the first stage of labour, but the effect on the second stage was more obvious, leading to outlet extraction in 50% of the primiparous women, compared to 12% of the controls. Transitory asphyxia at birth was observed in 4.5% of the infants of mothers with epidural block, but after 5 min, only 1% had an Apgar score of less than 7. Infants of mothers with epidural block were more often placed under observation or treated in the neonatal ward than infants in control groups.

Anesthesia, Epidural↗
PubMed1979

Effect of segmental epidural analgesia upon the uterine activity with special reference to the use of different local anaesthetic agents.

Segmental epidural block was given to 60 primiparous women during vaginal delivery, and the effect of the block on the uterine activity was studied after the first epidural injection. The women were divided into two main groups, according to whether or not oxytocin was used for stimulating the uterine contractions, and three different local anaesthetics--lidocaine-adrenaline, bupivacaine-adrenaline and plain bupivacaine--were tested. There was a transitory decrease in uterine activity in all women after the block was applied. In women with normal uterine activity before the block, a return to almost pre-analgesic values was noted within 30 min after the block, whereas in women treated with oxytocin there was still a reduction of 15-17% at this time. The reduction was caused by a decreasing intensity and at the same time an increase in the variability of the intensity, manifested as an increase in the coefficient of variation for this variable. There were no significant differences between the local anaesthetic agents tested, but addition of adrenaline to the bupivacaine solution resulted in a more marked decrease in uterine activity in women treated with oxytocin.

Anesthesia, Epidural↗
PubMed1979

Time factor in oxygen transfer from mother to fetus.

The time factor in the oxygen transfer from mother to fetus was studied by the tcPO2 technique. When a fairly constant fetal circulation made estimation possible, the decrease in fetal tcPO2 synchronous with and due to the uterine contractions in more than 400 events was always delayed 50--60 sec. Since the time lag in the increase in fetal tcPO2 following administration of pure oxygen to the mother was found to be of the same order of magnitude, the placental part of the delay in the oxygen transfer from mother to fetus can be assumed to be 50--60 sec. This determination supports the prevalent hypothesis that type II dips or late decelerations in the fetal heart rate are caused by hypoxia while type I dips or early decelerations are initiated by other factors.

Female↗
PubMed1979

External cephalic version in breech presentation under tocolysis.

A prospective trial is presented of the benefits and risks of external cephalic version in breech presentation. From January through October 1977, attempts at external version were performed in 53 cases with a success rate of 70%. The version technique is described. Mode of delivery after the maneuver in mothers with breech presentation who for different reasons were not included in the series is reported as well. Both the incidence of breech presentation and the incidence of cesarean section in breech presentation were reduced during the period of study. No serious complications in association with attempts at external version were observed.

Apgar Score↗