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Biomedical subjects

M Wikland

Publications and source records attributed to M Wikland.

106 records · Page 6Linked to original sources
PubMed1983

The role of prostaglandins in the stimulatory action of catecholamines on myometrial activity in term pregnant women.

The response of small strips of human myometrium to catecholamines was investigated using a superfusion technique. In term pregnant uteri, adrenaline (A) and noradrenaline (NA) caused contraction of both the upper and lower segments, but there was no significant change in response depending on whether or not the patient was in labor. Phenoxybenzamine blocked the excitatory effect of both A and NA, suggesting an alpha-adrenoceptor-mediated effect. Propranolol did not enhance the effect of A or NA, indicating that stimulation of beta-adrenoceptors does not contribute to the effect on the pregnant human uterus. Pretreatment of the tissue with indomethacin or eicosa-5,8,11,14-tetraynoic acid (ETA), drugs known to block endogenous prostaglandin synthesis, markedly reduced the effects of both A and NA. This suggests a specific role of prostaglandins in the mechanism of action of catecholamines on the human myometrium.

Adrenergic Agonists↗
PubMed1983

The effect of prostaglandin I on the contractility of the term pregnant human myometrium.

Small myometrial strips were dissected from the upper and lower segments of the term pregnant human uterus. The specimens were superfused in organ chambers and contractile activity was recorded isometrically. In strips from the upper segment, prostacyclin (PGI2), induced an initial excitatory response followed in the majority of experiments by transient inhibition. In the lower segment the response was generally the same although direct inhibition without initial stimulation occurred in some cases. During the period of inhibition the specimens were refractory to iterated exposure to PGI2. Furthermore, during this period of PGI2-induced inhibition the muscle strip was also refractory to PGE2 but responded to PGF2 alpha and oxytocin by stimulation. After inhibition of spontaneous contractile activity induced by indomethacin PGI2 induced an excitatory response. The results do not indicate any critical change in the myometrial responsiveness of the upper uterine segment to PGI2 during labor. In strips from the lower segment obtained before labor there tended to be a dominance of non-responders and inhibition only as compared to the results during labor. Nevertheless, whether or not PGI2 under physiological or pharmacological conditions has any significant influence on the contractility of the term pregnant human uterus, still remains obscure. As judged from earlier reports from our laboratory and the present study it is evident that the uterine vessels are considerably more sensitive to the action of PGI2 than the myometrium.

Dinoprost↗
PubMed1983

Collection of human oocytes by the use of sonography.

A technique for ultrasonically guided percutaneous oocyte aspiration was developed utilizing standard real-time, linear-array ultrasound equipment. Forty-four patients attending our in vitro fertilization and embryo transfer (IVF-ET) program were included in this study. In 38 patients, follicular puncture was performed under general anesthesia and in 6 cases performed under local anesthesia. Fifty-two follicles with a mean diameter greater than or equal to 18 mm were punctured, and 40 mature oocytes were recovered corresponding to a success rate of 77% per follicle. Six of the punctured follicles were considered cystic when the aspirated granulosa cells were examined microscopically and, if these were excluded, the corrected recovery rate was 87% per follicle. In two patients, ovulation had occurred at the time for oocyte collection. In one of these patients, a mature oocyte was, however, recovered from the pouch of Douglas by the use of sonography. On the basis of these results, ultrasonically guided puncture of follicles for collection of human oocytes in our IVF-ET program seems suitable for use in all cases where laparoscopy is presently used and, moreover, in cases with severe adhesions, where laparoscopy may fail.

Embryo Transfer↗
PubMed1983

Interaction between PGs and catecholamines on cervical collagen synthesis.

Specimens from the upper part of the cervix were excised and chopped into 1 mm thick slices. These were incubated in buffer containing [3H] proline fortified with PGE2 and/or NA and the incorporation into total protein was measured after various incubation periods. In certain experiments the slices were preincubated with reserpine to deplete the tissue stores of catecholamines. Both PGE2 and NA were able to influence the incorporation of [3H] proline in such a way that the stimulatory effect of PGE2 was counteracted by reserpine in the luteal phase of the cycle, while NA-stimulated incorporation of [3H] proline was inhibited by PGE2 in the late follicular phase. Both clinical and experimental studies have shown that PGs per se interfere with the biophysical and biochemical properties of the cervix. The present results indicate that there also exists an interaction between PGs and catecholamines.

Cervix Uteri↗
PubMed1983

A rare case of IUD expulsion through the fallopian tube.

This case report describes the expulsion of an IUD (Gravigard) through the Fallopian tube. Such a phenomenon has been suggested earlier but never reported. It is concluded that the shape of the IUD is of importance for such a route of expulsion.

Adult↗
PubMed1983

PGI2 may play a role in the pathophysiology of dysmenorrhea.

Small longitudinally or helically cut strips from the ascending branch of the uterine artery were mounted in organ chambers for isometric recording of contractile activity. PGI2(3-300 ng/ml) caused a concentration-dependent relaxation of spontaneously active preparations, whereas no inhibitory effect could be observed on non-active strips. Furthermore, the compound counteracted the stimulatory effects of PGE2, PGF2 alpha, and NA, but not that of transmural nerve stimulation. The effect of PGI2 could be of interest in that the compound may balance the action of vasoconstricting agents. A disturbance of this balance may be a hitherto unrecognized contributing pathophysiological mechanism in the development of dysmenorrhea.

Arteries↗
PubMed1983

Prostaglandins and oviductal function.

This review presents evidence of a specific involvement of PGs in the function of the human Fallopian tube. A role of PGE and PGF in ovum transport seems plausible, but data from human studies are still fragmentary. High estrogen levels in tissue at ovulation may cause 'tubal lock' by increasing the activity of the isthmic musculature. This effect might be exerted by an estrogen-dependent increase in the formation of PGF as well as by increased sensitivity to PGF. The elevation of progesterone levels in the early luteal phase would counteract the effect of estrogens by instead favoring E prostaglandins. PGE seems to relax the isthmic muscle, allowing the entry of the fertilized ovum into the uterine cavity.

Alprostadil↗
PubMed1982

Recruitment of an ovulatory follicle in the human following follicle-ectomy and luteectomy.

The study was undertaken to explore the time required for the selection and ovulation of a dominant follicle after interference with the normal menstrual cycle of fertile women. At routine laparotomy (sterilization) a leading follicle or a fresh corpus luteum was excised, and the day of the next ovulation was estimated by monitoring of serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone, and 17 beta-estradiol and by registration of the growth of the follicles through ultrasonic scanning. The results are in accordance with earlier observations in the rhesus monkey demonstrating that the recruitment and selection of an ovulation-competent follicle takes 12 to 14 days in the primate. Since this time is close to the length of the normal follicular phase and approximately the same after follicle-ectomy and luteectomy, the results suggest an importance of local factors in regulating follicle recruitment.

Adult↗
PubMed1982

Simultaneous recording of electrical and mechanical activity in isolated smooth muscle of the human oviduct.

Small strips from the circular muscle layer at the ampullary-isthmic junction of the human oviduct were suspended in an organ bath. Mechanical activity was recorded isometrically by a force displacement transducer and electrical activity was registered simultaneously by an extracellular glass-silver electrode. Spontaneous contractions were not associated with "burst" of action potentials but were preceded by a single spike with a duration of approximately 700 milliseconds. During the rest of the contraction there was a total absence of potential changes. Prostaglandin E2 (PGE2) abolished spike discharge leading to inhibition of mechanical activity. Prostaglandin F 2 alpha (PGF 2 alpha), on the other hand, increased the rate of action potentials and, hence, the frequency of contraction. However, neither PGE2 nor PGF2 alpha changed the configuration of the spike. It is concluded that in smooth muscle of the human oviduct, there is a high degree of agreement between the electrical and mechanical signals and that prostaglandins act by reducing or increasing the rate of spike discharge but not by influencing the character of the action potential.

Action Potentials↗
PubMed1982

Oxytocin, prostaglandins, and contractility of the human uterus at term pregnancy.

The contractile properties of myometrial "mini-strips" from the upper and lower uterine segments were studied by a superfusion technique. These samples of myometrium were taken from women delivered by elective cesarean section in the 39th week of pregnancy. The frequency of spontaneous contractions was significantly higher in isthmic myometrial specimens than in corpus specimens, whereas amplitude and duration of contractions did not differ. Both isthmic and corpus myometrium were stimulated by prostaglandin E2 at low concentrations and inhibited at high concentrations. PGF2 alpha induced an excitory response in the isthmic strips but surprisingly not in preparations from the corpus. However, PGF2 alpha restored normal spontaneous activity following inhibition of the contractility with indomethacin. Oxytocin caused an excitory response over a wide concentration range in both types of specimen and this response was not reduced by pretreatment with indomethacin. These findings suggest that endogenous prostaglandin synthesis is a necessary prerequisite for spontaneous myometrial activity at term pregnancy and that prostaglandins are not essential for the excitatory effect of oxytocin.

Adult↗
PubMed1981

Effects of prostaglandins on the isolated uterine artery of nonpregnant women.

Specimens from the ascending branch of the human uterine artery were obtained from 35 nonpregnant fertile women undergoing hysterectomy. The specimens were cut either longitudinally or helically and mounted in organ chambers for isometric recording of the contractile activity. Spontaneous phasic activity occurred in 30% of the specimens. Both PGE2 and PGF2 alpha caused an increase in basal tonus of the strips while PGI2 relaxed spontaneously active as well as PG- and norepinephrine (NE2)-stimulated preparations. PGI2 had no effect on nonactive specimens, NE and transmural nerve stimulation (TNS) induced contractile activity that could be blocked by phenoxybenzamine. PGI2 counteracted the NE-induced response but not that of TNS. It is concluded that PGI2, which is synthesized both within the vessel wall and the myometrium, has a potent relaxing effect on uterine arteries and that the compound may balance the effect of vasocontricting substances.

Adult↗
PubMed1981

PGH2, TxA2 and PGI2 have potent and differentiated actions on human uterine contractility.

The contractile response to three different prostanoids of the isolated human myometrium and the different layers of the uterotubal junction (UTJ) was studied in vitro. The prostaglandin endoperoxide, PGH2, stimulated contractility of both the myometrium and the outer and inner muscle layers of the UTJ, whereas the intermediate layer of the UTJ was inhibited. Thromboxane A2 generated from PGH2 and a thromboxane synthase preparation caused a stimulation of both the myometrium and all three layers of the UTJ. The stimulatory response to TxA2 occurred at concentrations as low as 50-70 pg/ml. The sodium salt of PGi2 was found to relax both the myometrium and all the layers of the UTJ. Intravenous administration of PGI2 in repeated doses between 2-8 microgram induced facial flushing and headache but had little if any effect on in vivo uterine contractility. At least under in vitro conditions, these short-lived prostanoids and/or their metabolites apparently have a specific action on uterine contractility, an action which is manifested at comparatively low concentrations.

Adult↗
PubMedDate not supplied

The use of hyaluronic acid for sperm selection--evaluation of sperm head ultrastructure.

The percentage of normal spermatozoal plasma membranes and acrosomes was evaluated by electron microscopy before and after a two-step semen washing and swim-up into culture medium containing either bovine serum albumin or hyaluronic acid. Both techniques of sperm selection increased the concentration of motile spermatozoa when compared with the fresh ejaculate (P less than .001). The percentage of sperm with ultrastructurally intact plasma membranes and acrosomes was increased after both separation procedures in comparison with the original ejaculate (P less than .01). In addition, both techniques of sperm selection significantly reduced the content of sample debris, granulocytes, and nonviable spermatozoa (P less than .01).

Acrosome↗
PubMedDate not supplied

Laparoscopy versus ultrasound guided puncture for oocyte retrieval.

IVF/ET has during the last 5 years gone through a dramatic development and expansions. Since approx. 10% of the population in fertile ages has infertility problems in the Western world the demand for IVF units outside larger University hospitals with considerable resources has become urgent. To reduce costs a trend towards simplification without loss in quality has been an ambition for everyone involved. The exchange of laparoscopic techniques to simpler and cheaper sonographic methods is one step in that direction. The present review is a comparison between the various techniques for oocyte retrieval taking into consideration the principle qualitative aspects to avoid introducing a new technique which is inferior to the originally applied technique. In summary sonographic techniques seem to fullfill these quality requirements and will for such reasons in many IVF groups gradually replace laparoscopy.

Female↗