Ingemar Joelsson

The Immediate Effect of A β‐Adrenergic Agonist (Salbutamol) on Carbohydrate and Lipid Metabolism During the Third Trimester of Pregnancy

Abstract. The responses of plasma insulin and the C‐peptide of proinsulin, glucose, lactate, free fatty acids (FFA), glycerol, D‐β‐hydroxybutyrate and alanine to a β2‐adrenergic agonist (salbutamol) were determined in 5 patients during the last trimester of pregnancy before labor. Salbutamol was given as an infusion in the same dosage as is used to inhibit uterine contractions in cases of premature labor and in obstetric emergencies. The infusion of salbutamol was given for 45 min, accompanied by repeated sampling of arterial blood. All patients developed moderate tachycardia and exhibited metabolic effects following salbutamol infusion, implying marked increases in plasma levels of insulin, C‐peptide, glucose and lactate. An increased rate of lipolysis was evident from the rises of FFA, glycerol and D‐β‐hydroxybutyrate. Plasma levels of alanine declined, possibly due to stimulation of glu‐coneogenesis. It is unlikely that these acute maternal metabolic changes would have significant adverse effects on the fetus.

Quantification of Fetal Heart Rate Variability in Relation to Oxygenation in the Sheep Fetus

Beat-to-beat variability has been suggested as a sensitive indication of fetal well-being. The suggestion originates from case reports of observed decrease in variability preceding clinical signs of fetal asphyxia and fetal death. Against this background a study was performed to evaluate possible changes in heart rate variability in relation to changes in fetal oxygenation. Chloralose-anesthetized sheep were used. Short-term hypoxia was produced without acidosis. The FECGs were recorded on magnetic tape and later analysed by scrutinizing each QRS complex prior to the trigger of a rate meter. The differential index (DI) described by Yeh and co-workers was chosen because it is easily computed and reflects the variability of coefficient of variation for two successive R-R intervals. In contrast to the generally held view of a progressive diminution of variability during the development of asphyxia, the variability was found to increase parallel with a decrease in fetal arterial PO2 determined on blood samples withdrawn at intervals and ranging between 26 and 10 mmHg. The correlation between variability and PO2 in the range below 8-10 mmHg is still to be determined.

Acridine Orange in Gynecologic Cancer: II. The Effect of Stain Receptors on some Proton Magnetic Resonance Parameters

Abstract. The methyl line of the proton magnetic resonance spectrum of acridine orange zinc trichloride, dissolved in heavy water, has been studied. This line consists of two overlapping components with different widths. A mathematical technique has been developed to resolve the two components quantitatively. Their relative proportion depends on the acid‐base state of the molecular environment. If the stain is adsorbed on albumin the narrow component quickly disappears, while adsorption on RNA gives rise to a broadening of the narrow line. With large amounts of albumin or RNA, both components disappear. DNA strongly adsorbs acridine orange with complete disappearance of all NMR spectral lines. Mitochondria, submitochondrial particles and microsomes cause some broadening of the narrow component of the methyl line. Due to the obvious alterations of the NMR spectrum, in the circumstances mentioned, this type of spectroscopy may be used for the biophysical characterization of interaction mechanisms between acridine orange and various proteins, nucleic acids and cell fractions.

THE ABSORPTION OF TRITIUM‐LABELLED PROSTAGLANDIN E1 FROM THE VAGINA OF NON‐PREGNANT WOMEN

Tritium labelled prostaglandin E1 was deposited for 6 hours in the posterior fornix of 7 normally menstruating volunteers who were without any signs of infection. 10-25% of the radio activity administered was recovered in the urine within 24-32 hours. The application of a cervical cup to the cervix failed to influence the absorption which was estimated to be 20-50%. The physiological significance of this absorption remains uncertain. No conclusion can be drawn from this investigation regarding the absorption rate during this period since elimination through the kidney is so slow.

THE IN VIVO EFFECT OF OXYTOCIN AND VASOPRESSIN ON THE NON PREGNANT HUMAN UTERUS

IN a previous study (Sandberg et al., 1959) in which the response of myometrial strips from non-pregnant patients to large doses of oxytocin was examined, difference in sensitivity was encountered between tissue from the corpus and that of the isthmus, the isthmic myometrium being almost insensitive to the polypeptide. The principal effect was an increase in tonus which was more pronounced when the specimen was obtained during the proliferative than the secretory phase. Recently Fuchs and Fuchs (1963) have presented additional data regarding the in vitro response of human myometrium to oxytocin. The authors showed that oxytocin had no visible effect during the proliferative phase but a definite, though weak and transient, effect on the frequency of the contractions during the secretory phase. McGaughey and co-workers (1964) have tested the effect of oxytocin as well as vasopressin on nonpregnant human uterus (corpus musculature) in vitro, using doses in the range of 0.004-40.000 m u . per ml. They were unable to demonstrate any difference in response between the myometria1 preparations obtained during the first and the second half of the menstrual cycle. Oxytocin produced a decrease in tonus and, in high concentrations, also a decrease in amplitude. With increasing doses there was a progressive reduction in the frequency of contractions. According to their findings oxytocin acted as a depressant on the non-pregnant human uterus. Vasopressin, on the contrary, was found to provoke a significant increase in tonus and a decrease in amplitude. The alteration in frequency was phasic and showed a decrease at low concentrations and an increase at high concentrations. Several investigators have shown that in the uterus of the rabbit the results obtained in vitro are similar to those in vivo (Schofield, 1955; Bengtsson, 1957; Fuchs and Fuchs, 1960). The in vitro results for human myometrium, however, do not correspond to those obtained from studies in situ (Moir, 1944; Garrett, 1954, 1955) and the findings have been at variance (Sandberg et al., 1958). Therefore the in vivo effect of oxytocin and vasopressin has been studied, paying particular attention to the separate responses of the uterine corpus and isthmus.

In Vivo Determination of the Stress‐Strain Relation of the Human Myometrium

Abstract. Smooth muscle is capable of responding by contraction to mechanical distension. Neither the structural basis for this phenomenon nor the theories of smooth muscle behavior are completely clear. A method is now described by which the contractile response to mechanical distension of the human uterine muscle in vivo is determined. The distension is enforced sinusoidally within the frequency range 0.005–2 Hz, by filling and emptying a rubber balloon introduced into the uterine cavity. A tonometric index of the myometrium is defined using Hooks law after the approximate evaluation of a contractile modulus and the tangential stress and strain in the inner layer of the uterine wall. The regression line of indices upon frequency is calculated and intercept and regression coefficient of the equation for basic conditions are compared with those obtained during administration of pharmacologically active agents. It is suggested that the differences in intercepts and regression coefficients be used as a measure of drug effect.

Mechanics of Human Myometrium Studied with Dynamic Tests in Vivo

A technique for dynamic studies of the mechanics of the uterine musculature in vivo is described, based on the registration of pressure responses to sinusoidally imposed changes in volume. The final amplitudes are varied between 1 and 9 ml and the frequency of volume changes is selected between 0.005 and 0.1 Hz. Having defined the frequency of the spontaneous activity of the uterus, end pressure, area of hysteresis and distance between the limbs of the loop are used as parameters to characterize the mechanical properties of the myometrium. The potential of the method includes the study of the effect upon the myometrium of pharmacologic agents with oxytocic and relaxant effects.

The Radiofrequency Field Distribution Surrounding Coils for Intrauterine Diagnostic Procedures: I. Geometrical Factors

The absorption of radio frequency energy emitted by a small intrauterine coil has been used for intrauterine scanning in order to localize intrauterine pathology, especially cancer. In order to improve the method the distribution of RF field intensities around coils of different geometries has been measured. Ringshaped coils have longer axial effective fields than other coil geometries, probably allowing diagnosis of more deeply lying processes. Still deeper processes may be reached by two‐coil systems of special design. The RF absorption has been shown to follow the squared value of RF field intensity.

In Vivo Determination and Cyclic Variability of Intrauterine Volume

A description is given of hysterometry, a method for in vivo determinations of the pressure response to linear increments in volume of the non‐pregnant human uterus. The analyses of pressure‐volume diagrams obtained during consecutive phases of the menstrual cycle reveal that the volume of the uterine cavity during the secretory phase is larger than during the proliferative phase by a factor of 2 or more. If ovulation does not occur, however, the relation between pressure and volume remains unchanged throughout the interval between two menstrual flows. It is suggested that hysterometry might prove of value for assessing the effect of hormones and pharmacologically active agents upon the myometrium.

A Flowmeter for the Determination of Small Flow Rates

A method, capable of determining very small flow rates, 0.01–0.10 μ1·sec−1, is described. The technique, which is devised with the aim of measuring the rate and fluctuation in the flow of uterine secretions, is based upon the detection of the asymmetry in the dispersion of heat, added as a label. The accuracy in measurement of basal secretion rates over long periods of time is ± 15%, the accuracy in the detecting of flow fluctuations is ± 5%.