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Biomedical subjects

U Ulmsten

Publications and source records attributed to U Ulmsten.

At least 91 records · Page 5Linked to original sources
PubMed1995

Morphometric analysis of gap junctions in nonpregnant and term pregnant human myometrium.

BACKGROUND AND METHODS: Some structures in the human myometrium, namely; caveolae, extracellular space and gap junctions were quantified in tissues from nonpregnant women, women who were not in labor, and women in spontaneous labor or oxytocin-induced labor, in order to reveal morphologic differences that would contribute to explaining the events leading to labor. Transmission electron micrographs taken from tissues from twenty-four pregnant and ten nonpregnant women were studied. RESULTS: Differences were observed in cell growth which was accompanied by enlargement of the extracellular space, and in gap junctions. Gap junctions were demonstrated in nonpregnant women, and even in one postmenopausal woman. Their frequency and size increased gradually between groups of pregnant women in the order of non-labor, oxytocin-induced labor and spontaneous labor. The increase in size of the junctions was less than the increase in number. CONCLUSIONS: Gap junctions are most frequently found in human myometrial cells in spontaneous labor, which strongly suggests a role for these structures in the termination of pregnancy. The effect of oxytocin on the appearance of gap junctions was negligible; hence, the contribution of oxytocin to establish myometrial contractile synchronicity is thought to be minor. Caveolae are probably not relevant for the initiation of labor as their distribution did not differ between the groups.

Adolescent↗
PubMed1995

Intravaginal slingplasty (IVS): an ambulatory surgical procedure for treatment of female urinary incontinence.

A new ambulatory procedure for treatment of female urinary incontinence (intravaginal slingplasty, IVS) was performed on 50 patients. In all patients the surgical procedure was carried out under local anaesthesia and without postoperative urinary catheterization. The technique has been elaborated from previous experimental and clinical studies and aims at restoration of the pubourethral ligament and the suburethral vaginal hammock. Thirty-eight patients suffered from genuine stress incontinence as objectively verified and 12 patients had symptoms and signs of both urge and stress incontinence. Thirty-nine (78%) patients were completely cured from their stress incontinence symptoms. Another six patients (12%) reported a considerable improvement of their urinary incontinence leaking only occasionally. Concerning urge incontinence symptoms a significant relief of the symptoms was obtained in 6 of 12 patients. No intra- or post-operative complications occurred.

Adult↗
PubMed1995

In vitro effect of Hepes buffer on maintaining the number of gap junction plaques in human myometrium at term.

In human myometrium, at various stages of labour and in correlation with the concentration of progesterone and estradiol in maternal blood the formation of gap junctions has been described previously by electron microscopy and laser confocal microscopy of immunohistochemically stained myometrial sections. The present investigation focused on the effect of continuous exposure of isolated human myometrium at term to Hepes buffer, on the number of gap junction plaques. Biopsies of myometrium were obtained from 5 pregnant women at term: they had an elective caesarean operation in the 37th or 40th week of pregnancy. The biopsies were immersed immediately in Hepes buffer, trimmed under a stereo microscope into small strips and kept in warm (37 degrees C) oxygenated Hepes buffer supplemented with glucose (0.01 mM). Then some strips of myometrium were incubated at 37 degrees C for 10, 20, 40, 55, and 180 min. The number of gap junction plaques were counted: it decreased in strips of myometrium after 10, 20, 40, 55, and 180 min of in vitro experiment (P < 0.01 vs control). In some of our experiments, the decrease in quantity of gap junction plaques was very dramatic and far below 50% of their numbers found in control specimens but never reached the zero value.

Biopsy↗
PubMed1994

Transvaginal sonography of the internal genital organs in postmenopausal women on low-dose estrogen treatment.

Thirty healthy postmenopausal women with symptoms and signs of atrophic vaginitis due to estrogen deficiency were examined with transvaginal ultrasound. The endometrial thickness, the uterus and the ovaries were measured before and after 6 months of treatment with a low dose of estradiol released from a vaginal ring. The mean endometrial thickness, before and after the treatment, was 2.9 mm and 2.5 mm, respectively. There were no changes in endometrial volume or uterine thickness and volume during the treatment period. The mean volume of the postmenopausal ovary before treatment was 4.2 ml, and there was no difference after treatment or between the right and the left side. With a low dose of estradiol, administered locally, all the women were relieved from their deficiency symptoms, without any effect on the endometrium, the uterus or the ovaries when measured by transvaginal ultrasound.

Journal Article↗
PubMed1994

Low energy charge and high adenosine content in smooth muscle of human bladder in comparison with striated muscle.

This study determined the energy charge, adenosine and inosine content of human bladder smooth muscle in comparison with striated muscle of the same individual. Biopsies were obtained from 21 women who were subjected to urethrocystopexy because of urinary stress incontinence. We found that the ATP content of bladder smooth muscle was only about one-eighth of that of striated muscle. The energy charge of bladder smooth muscle was 0.78 +/- 0.13, which is low compared with striated muscle (0.92 +/- 0.02). The adenosine content of bladder smooth muscle was 6.7 times higher than striated muscle and the adenosine/ATP ratio was 1:9 compared with 1:450 for striated muscle. These findings were in accordance with our previous studies on uterine smooth muscle.

Adenosine↗
PubMed1994

Promotive effect by prostasomes on normal human spermatozoa exhibiting no forward motility due to buffer washings.

Prostasomes, small corpuscular organelles derived from the prostate gland, were isolated from human seminal plasma by means of ultracentrifugation and Sephadex G 200 chromatography to assess objectively their promotive effect on the motility of buffer-washed normal human spermatozoa exhibiting no forward motility. Prostasomes were efficacious in about 70% of these spermatozoa, and a maximum value was obtained with prostasomes at a concentration corresponding to a protein content of 0.7-0.8 g/l followed by a plateau at higher concentrations. Addition of albumin alone resulted in a similar response although at a somewhat lower level and about 50% of the spermatozoa were rendered motile with a maximum effect of albumin at about 2.5 g/l. Albumin concentrations exceeding 3 g/l were less active. At protein concentrations of 0.25 g/l, prostasomes were superior to albumin in every respect concerning the effects on various sperm movement characteristics. These divergent effects were abolished when comparing prostasomes corresponding to a protein concentration of 0.75 g/l with albumin at 2.3 g/l, i.e. at their respective optimum concentration. Heat treatment and ultrasonication of prostasomes did not affect their motility-promoting properties. Some problem of sperm dysfunction has generally been considered to be a major contributory factor to infertility. By supplementing sperm preparations with postasomes in cases of established male factor, the already poor quality spermatozoa may more frequently be rendered capable of fertilization after insemination.

Humans↗
PubMed1994

Morphometric analysis of gap junction density in human myometrium at term.

In the human myometrium, the formation of gap junctions in the various stages of labor and, in correlation with the concentration of progesterone in the maternal blood, has not been described adequately. The accepted hypothesis that raised concentrations of progesterone in maternal blood in animals prevent the formation of gap junctions was scrutinized in human myometrium. Myometrial tissue was examined by electron microscopy for the presence of gap junctions and analyzed morphometrically in 17 women who had an elective or emergency cesarean operation at the 38th or 39th week of pregnancy. The concentrations of progesterone and estradiol in the maternal and cord blood was measured by means of radioimmunoassay. The frequency and area of gap junctions varied in relation to the presence or absence of labor. In the myometrium of women in labor, gap junctions were most frequent (5.2/1000 microns of cell membrane), their area largest (0.32 microns 2/1000 microns of cell membrane) and their fractional area greatest (0.20%). When the women were not in genuine labor or when contractions were weak, the percentage fractional areas of gap junctions were low (0.020-0.090) and the gap junctions very small. In the pre- and active phases of labor, the concentration of progesterone in maternal blood was significantly higher (p < 0.025 and 0.03 respectively) than in women who were not in labor. Hence, despite high concentrations of progesterone in the maternal and cord blood at term, the myometrium presented numerous gap junctions of relatively large area.

Adult↗
PubMed1994

Direct intracellular injections for studying human myometrial gap junctions prior to labor.

Direct intracellular microinjection of a fluorescent dye (Lucifer Yellow) was performed on ex-situ muscle strips from term pregnant women not in labor. The aim was to characterize the intracellular distribution of LY to obtain criteria for an intracellular injection in whole mounts and ultimately to study the gap junctional communication between myometrial cells in those tissues. Fifteen injections performed on biopsies from ten cases showed a well-bordered fusiform shape and were considered to be intracellular. The intercellular spread of the dye into an adjacent cell was observed in three injections (three cases). The average cell dimension was 284 +/- 95 microns for length and 5 +/- 1.5 microns for width (n = 17). The intracellular injection was confirmed by light microscopy of cross sections. It is concluded that limited coupling exists between myometrial cells of women prior to labor.

Cell Communication↗
PubMed1994

Antisera against three connexin43 fragments react with a 43-kD protein localised to gap junctions in myocardium and human myometrium.

Gap junctions are thought to play an essential role in the control of parturition. In this study we attempted to synthesise three short peptides which match the portion of the amino acid sequence of the connexin43, protein predicted from the nucleotide sequence of cDNA clone and to produce an anti-peptide antibody which would detect gap junction protein in human myometrium. Three peptides were synthesized: (1) RKEEKLNKKEEE, (2) EJKKFKYGJEEH and (3) KNRVKGRSDPYH. Antibodies against these peptides were raised in rabbits, screened for reactivity and specificity using dot blot assays and used for immunocytochemical staining of heart and myometrial tissues.

Amino Acid Sequence↗
PubMed1994

Intravaginal slingplasty.

After referring the causes of failing of many operative methods to cure female urinary incontience the technique of an intravaginal sling plasty is described in detail inclusively the pre- and postoperative care of the patient.

Female↗
PubMed1994

Interaction of sex steroids and oxytocin on term human myometrial contractile activity in vitro.

OBJECTIVE: To investigate the interactions of progesterone, estradiol (E2), and oxytocin in regulating the contractile activity of term human myometrium in vitro. METHODS: Myometrial tissues from 12 term pregnant women were obtained from the lower uterine segment at elective cesarean and immediately immersed in Hepes buffer with and without progesterone and progesterone plus E2. Oxytocin was freshly dissolved in solutions when the superfusion was started. Muscle biopsies were dissected along the bundles of smooth muscle under a stereomicroscope, and the preparations were mounted in six tissue baths superfused with different hormonal solutions. The isometric tension was recorded during the experimental time. RESULTS: During the 2-hour contraction period, increased frequency (P < .01 for each) and decreased activity area (P < .01 for each) and duration of contractions (P < .01 for each) resulted from superfusion of muscle strips with progesterone plus oxytocin, progesterone plus E2, and a combination of progesterone, E2, and oxytocin, compared to that found with buffer alone. The higher concentration of progesterone (5 micrograms/mL) plus oxytocin and progesterone plus E2 elevated the tonus (P < .05 and P < .01), whereas progesterone in combination with E2 and oxytocin decreased it (P < .05). The lower concentration of progesterone (0.5 microgram/mL) plus E2, or both in conjunction with oxytocin, had no significant effect on tonus as compared with buffer. CONCLUSION: The results suggest that progesterone and E2 have a direct effect on uterine excitability and a regulating influence on the oxytocin sensitivity of term human myometrium.

Adult↗
PubMed1994

Decreased collagen synthesis in stress-incontinent women.

OBJECTIVE: To determine whether there is a difference in collagen metabolism between comparable urinary stress-incontinent and -continent women. METHODS: Fibroblast cultures from skin biopsies were established from seven stress-incontinent and four continent women. Collagen production was investigated in these cultures between passages 3 and 7 by incubation with 3H-proline, followed by quantitation of 3H-proline and 3H-hydroxyproline after hydrolysis of proteins and separation by high-pressure liquid chromatography. The chemical amount of collagen was also quantitated using Sircol Red. RESULTS: Fibroblast cultures established from urinary stress-incontinent women accumulated 30% less collagen than comparable cultures from continent women. The differences were statistically significant (cell layer P = .038, medium P = .004; Student t test). These results were observed both when collagen concentration was measured with chemical methods and when the production of protein-bound 3H-hydroxyproline was quantitated. General protein synthesis was similar in the two groups. CONCLUSION: Our results suggest that women with urinary stress incontinence have an altered connective tissue metabolism causing decreased collagen production, which may result in insufficient support of the urogenital tract.

Cells, Cultured↗
PubMed1993

High adenosine content in human uterine smooth muscle compared with striated skeletal muscle.

We determined the concentrations of adenosine and some of its catabolic products in biopsy specimens from predetermined loci of human myometrium under different functional conditions to compare uterine muscle with rectus abdominis muscle from the same individuals. In order to achieve a good resolution in the separation of nucleosides and purine bases, a preseparation procedure was developed prior to analysis of these compounds on high performance liquid chromatography. Adenosine occurred in a nearly 70-fold higher concentration in smooth uterine muscle in comparison with striated skeletal muscle. Similarly, myometrial inosine and hypoxanthine were 7- and 2.4-times in excess over the rectus muscle, whereas xanthine was scarcely and rather evenly represented in the two types of muscles. The uterine content of adenosine and inosine was distinctly higher in pregnant women compared to non-pregnant ones. A regional difference existed for adenosine, with 3.3 times higher concentration in fundus uteri compared to the isthmic part. A reverse pattern was observed for hypoxanthine and inosine, being 2-3 times more frequent in the isthmic part. The orthophosphate concentration was not stoichiometrically related to the adenosine concentration in a simple way, being 2-3 times lower in uterine muscle compared to the skeletal muscle. A significant correlation existed between uterine contents of AMP and adenosine and similarly, significant inverse correlations were apparent between uterine ATP and ADP contents and energy charge on one hand and adenosine content on the other.

Adenosine↗
PubMed1993

Energy economy in the pregnant human uterus at term: studies on arteriovenous differences in metabolites of carbohydrate, fat and nucleotides.

Metabolic regulation was studied in the pregnant human uterus by determining its uptake and release of various substrates, some of which are commonly used as a fuel and some are markers of disturbed energy status in cells. Ten healthy women with normal pregnancy were examined when undergoing elective Caesarean section at term, before onset of labour. Carbohydrate metabolites (glucose, lactate and pyruvate), fat metabolites (free fatty acids (FFA) and glycerol) and nucleotide metabolites (hypoxanthine, xanthine and urate) were determined in arterial (radial artery) and venous (plexus of the uterine and ovarian veins) blood. In addition the arteriovenous difference in each substance across the uterus was calculated. A distinct uptake of glucose was a typical finding in the pregnant uterus as reflected by a positive difference. On the other hand, glycerol and FFA were released from the pregnant uterus. Similarly, a degradation of adenine-containing nucleotides seemed to be continuously ongoing in the pregnant uterus, since oxypurines displayed a negative difference as well.

Adult↗
PubMed1993

Bladder instability in women: a premature activation of the micturition reflex.

Urethrocystometry was performed during a provocative handwashing test in 163 patients, 115 of whom had a prior history of urge incontinence. Almost invariably, a rise in detrusor pressure, when present, followed a fall in urethral pressure, and both were preceded by urge symptoms. This pattern appears to conform to the concept of "urethral instability", "detrusor instability" and urge incontinence being different manifestations of a prematurely activated micturition reflex.

Adult↗
PubMed1993

Localization of steroid hormone receptors in the pelvic muscles.

After the menopause the pelvic floor becomes progressively weaker, one consequence of which is the increasing incidence of prolapse and urinary incontinence. It is plausible that the reduction in estrogen levels postmenopausally is an etiological factor in these problems. For the pelvic floor muscles to be considered as target organs for estrogen, demonstration of the presence of estrogen receptors is required. The present study aims to confirm previous findings of estrogen and progesterone receptors in the levator ani muscle, and to further localize them histologically. In seven women biopsies from the levator ani muscle were taken and analyzed immunohistologically with monoclonal antibodies for estrogen and progesterone receptors. The receptors were detected in the nuclei of connective tissue cells and striated muscle cells. These findings provide a scientific basis for a possible beneficial effect of estrogen therapy, as a complement to other therapies, in prolapse and urinary incontinence.

Adult↗