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Biomedical subjects

L P Bengtsson

Publications and source records attributed to L P Bengtsson.

15 recordsLinked to original sources
PubMed1979

Interrelations between plasma and tissue concentrations of 17 beta-oestradiol and progesterone during human pregnancy.

Oestradiol and progesterone concentration in plasma, decidua, myometrium and placenta obtained from women undergoing Caesarian section at term and abortion at weeks 16-22 of pregnancy were determined. There was a significant increase in oestradiol concentration (per g wet wt) both in placenta, decidua and myometrium from mid-term to term. Both at mid-term and term oestradiol concentrations in decidua and myometrium were much smaller than those in the plasma (per ml). Progesterone concentration in placenta and in myometrium did not increase from mid-term to term where it increased significantly in decidua. Decidual and myometrial progesterone concentrations at mid-term were 2-3 times higher than those in plasma, but at term the concentrations in both these tissues were lower than in plasma. The ratio progesterone/oestradiol in plasma, decidua, myometrium and placenta at mid-term was 8.7, 112.2, 61.4 and 370.0, respectively, and it decreased significantly in the myometrium and placenta but was nearly unchanged in plasma and decidua at term. The general conclusion to be drawn from the present study is the lack of correspondence between the plasma concentrations and the tissue concentrations of female sex steroids during pregnancy.

Decidua↗
PubMed1978

17 beta-Estradiol and progesterone concentrations in myometrium of pregnancy and their relationships to concentrations in peripheral plasma.

17 beta-Estradiol (E2) and progesterone (P) concentrations in blood and in the myometrium of human pregnancy at term (n=33) and in a few samples (n=5) around midterm of pregnancy were determined. E2 concentration in the myometrium (per g wet wt) at midterm was lower than the concentration in the plasma (per ml) so that the myometrium to plasma (My:Pl) ratio was 0.7. Relative to plasma concentration, the myometrial E2 increased little from midterm to term so that My:Pl was only 0.2 at term. Although P concentration in the myometrium was much greater than that in the plasma at midterm, My:Pl ratio being 2.2, it was lower than that in plasma at term so that My:Pl ratio was only 0.6. A fairly good correlation between plasma steroids and the myometrial steroids was observed at midterm but was distorted at term, probably due to saturation of the tissue-binding capacity. Steroid concentrations determined on the basis of protein showed a good correlation to the values expressed on the basis of wet weight. Whereas myometrial E2 concentration was significantly influenced by the distance from placenta, P concentration was not.

Estradiol↗
PubMed1978

Recording of myometrial activity in the non-pregnant human uterus by a micro-transducer catheter.

A micro-transducer catheter was tested in vitro and in vivo for recording of myometrial activity in the non-pregnant human uterus and was also compared with conventional fluid-filled, open end catheters previously used for recording intra-uterine pressures. The micro-transducer catheter had a frequency response far above that of fluid-filled, open end catheters. It was easily introduced through the uterine cervix and was never obstructed. Provided that the sensory surface of the micro-transducer was kept from direct contact with the uterine wall by some special arrangement it gave recordings of the intra-uterine pressure, that were practically identical with those obtained by an open end catheter.

Catheterization↗
PubMed1977

Uterine activity in diabetes insipidus.

In two nonpregnant women with cranial diabetes insipidus, myometrial activity under different hormonal conditions was studied by intrauterine pressure recording. Recordings were performed when the women were under the influence of their regular treatment with desaminocys1-D-arg8-vasopressin (DDAVP), and when they had fully developed symptoms of their disease. Uterine activity was similar to that found in normal women under the same hormonal conditions, and generally did not change when symptoms of lack of vasopressin appeared. Both DDAVP (15-20 microgram), given intranasally, and lysin vasopressin (0.2 IU), given intravenously, stimulated uterine activity, particularly in late secretory menstrual phase. It is suggested that endogenous vasopressin is of minor importance for the induction of spontaneous uterine activity in nonpregnant women.

Adult↗
PubMed1976

The risk of pelvic inflammatory disease in women using intrauterine contraceptive devices as compared to non-users.

The frequency of women using an intrauterine contraceptive device (I.U.D.) among 515 patients presenting with acute, laparoscopically verified salpingitis, has been compared with the corresponding frequency in 741 sexually active women who were matched to the patients by date of birth, domicile, and socioeconomic status. The frequency of I.U.D. use was significantly (P less than 0-001) higher in the patients than in the controls. It was estimated that the relative risk of acute salpingitis for any woman using an I.U.D. was 3-fold as compared to non-users. For women using I.U.D.s who had not been pregnant at any time, the corresponding risk was found to be 7-fold.

Acute Disease↗
PubMed1976

Mechanism for increased production of prostaglandins in labour.

It is proposed that uterine hypoxia, beginning initially with the uterine contractions in late pregnancy, leads to the increased formation of free fatty acids. The liberated fatty acids are then used to form prostaglandins and they can also act on mitochondria to release calcium. The released calcium can directly activate contractile proteins and/or can further stimulate phospholipase A (active at neutral pH) and thereby reinforce the progressive production of prostaglandins.

Calcium↗
PubMed1976

Levels of free and protein-bound progesterone in plasma during late pregnancy.

Using a filter method, levels of free (unbound) and protein-bound progesterone in blood samples were measured serially from the 23rd week of pregnancy until delivery in 16 healthy women. In addition, total estrogen and progesterone concentrations were determined by radioimmunoassay. The levels of both free and total progesterone increased steadily until the end of pregnancy. Free progesterone increased with advancing pregnancy more in proportion to the total progesterone, as it rose from 6% (of total) at week 24 to 13% at week 40. Both free and total progesterone decreased markedly very soon (2 h) after delivery. However, the corresponding decrease in the level of free progesterone was considerably less, with the result that it rose to 19% of the total, the greatest proportion of free progesterone observed at any time. The levels of both total estrogen and progesterone in plasma increased with advancing pregnancy, and at no time, prior to delivery, was there a significant fall in progesterone or an abrupt rise in estrogen.

Blood Proteins↗
PubMed1975

The relaxing effect of terbutaline on the human uterus during term labor.

The uterine and cardiovascular responses to the adrenergic beta2-receptor stimulator terbutaline (TRB) were investigated in 14 patients in normal term labor. TRB, administered intravenously at a rate of 10 to 20 mug per minute, effectively inhibited uterine activity in advanced labor and also expulsion. Intravenous injection of TRB, 250 mug, diminished oxytocin-induced uterine hyperactivity. No serious side effects of the drug were observed; the circulatory effects were minimal, except for a tolerable maternal tachycardia. The mode of action and clinical application of TRB for inhibition of unwanted uterine activity are discussed.

Abortion, Threatened↗
PubMed1975

Terbutaline inhibition of midtrimester uterine activity induced by prostaglandin F2alpha and hypertonic saline.

The effect of the beta receptor stimulator, terbutaline, on uterine activity induced by intra-amniotic injection of prostaglandin F2alpha or hypertonic saline was investigated in 20 patients undergoing therapeutic abortion in the second trimester. Intrauterine pressure was recorded, and the basal tone, intensity and frequency of contractions and "total" activity (expressed in Montevideo Units or MU), were measured. Uterine activity was higher in the prostaglandin group (mean value 393 MU) than in the hypertonic saline group (mean value 238 MU). However, terbutaline, infused at a rate of 5 to 20 mug/minute, decreased the activity by approximately the same absolute amount in the two groups to a mean value of 214 MU in the prostaglandin group and to 68 MU in the saline group. In some patients of the saline group, terbutaline completely inhibited uterine contractions. Basal tone, which was high in the prostaglandin group (mean value 28 mm Hg) decreased to a mean value of 17 mm Hg during terbutaline infusion. In the saline group the mean value for basal tone decreased from 10-5 to 7-5 mm Hg. It is concluded that uterine activity, induced by intra-amniotic injection of prostaglandin F2alpha or hypertonic saline, can be inhibited by terbutaline. The mechanisms of action for prostaglandins and hypertonic saline are discussed.

Abortion, Induced↗
PubMed1975

A technique for monitoring endometrial or decidual blood flow with an intra-uterine thermistor probe.

A technique is described for studying endometrial or decidual blood flow by introducing a thermistor, mounted in a flexible catheter, into the uterus. The technique was first tested in model experiments and in the pregnant rabbit and was then used to study the blood flow of the human uterus. In pregnant women, the thermistor was introduced between the decidua and fetal membranes, and in non-pregnant women, it was applied to the endometrium of the fundus. Intra-uterine pressure was recorded simultaneously. No complications were encountered in either pregnant or non-pregnant patients. Decidual or endometrial blood flow remained steady over long periods. There were transient fluctuations about the mean level, usually associated with myometrial contractions, but these could easily be distinguished from changes in the level of blood flow evoked by administration of vasoactive drugs.

Animals↗