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Biomedical subjects

A Norström

Publications and source records attributed to A Norström.

At least 55 records · Page 3Linked to original sources
PubMed1991

Comparison of endovaginal ultrasound and cytological evaluation of cystic ovarian tumors.

Endovaginal ultrasound is a good diagnostic tool for distinguishing between cystic and solid tumors. Unilocular cysts in the lower pelvis seem to carry a very low risk of malignancy in women of all ages. Cytological evaluation of the fluid from a cystic ovarian tumor has rather poor accuracy in diagnosing malignancy. For such a reason, this study compares the diagnostic accuracy of endovaginal ultrasound to that of cytology of the cyst content. Furthermore, we wanted to determine whether irrigation after puncture of a cystic tumor could increase the number of cells in the fluid and thereby increase the diagnostic accuracy of the cytological evaluation. Fifty women admitted to surgery due to a cystic tumor were endovaginally scanned the day before surgery. After the intact tumor had been removed from the abdomen, its contents were aspirated by means of a double-channelled needle. Irrigation was performed with Ringer acetate. Cytological evaluation was performed on both portions of the cyst fluid. The negative predictive value with respect to malignancy was 77% for cytology of the first portion of the aspirate, 81% for irrigation, and 100% for ultrasound. The corresponding figures for positive predictive value were 100%, 100%, and 73%. We conclude that cytological evaluation after irrigation of a cystic ovarian tumor does not significantly increase accuracy in diagnosing malignancy compared to endovaginal ultrasound.

Adult↗
PubMed1990

Clinical effects and cervical tissue changes after treatment with 16,16 dimethyl-trans delta 2 PGE1 methylester in the first trimester.

Cervagem pessaries, containing 1 mg of 16,16-dimethyl-trans delta 2-PGE1 methylester, was administered in the posterior vaginal fornix 4 h before vacuum aspiration in the 1st trimester. The effects of cervical dilatation, cervical collagen metabolism and cervical smooth muscle activity were investigated. In treated women the mean cervical dilatation was 7.9 mm as compared with 3.9 mm in controls. The in vitro incorporation of 14C proline in cervical tissue as well as the hydrolytic activity against a synthetic "collagen-like" polypeptide was increased after treatment with cervagem. The cervical smooth muscle sensitivity to prostaglandins, as revealed by inhibition of muscle activity, was higher in treated women than in controls. It is concluded that cervical dilatation, as induced by cervagem, involves an adaptation of both connective tissue and smooth muscle components.

Abortifacient Agents↗
PubMed1990

Tumors in the lower pelvis as imaged by vaginal sonography.

Ultrasound is a sensitive tool for the diagnosis of cystic tumors in the lower pelvis of women. Most knowledge about the ultrasound image of such tumors is based on abdominal scanning. The value of vaginal sonography for evaluation of such tumors has, to the best of our knowledge, so far not been studied. This study was aimed at relating the vaginal sonographic image of tumors in the lower pelvis with the results of macro- and microscopic examination of the tumor. Special interest was paid to establishing ultrasound criteria for classifying unilocular tumors as benign or malignant. One hundred and eighty women who were operated on for pelvic tumors were included in the study. All women were evaluated by vaginal sonography the day before surgery. Ninety-four women were postmenopausal and eighty-six were still menstruating. Vaginal ultrasound characterized the tumor correctly as related to macroscopic examination in 96% (172/180). The sensitivity of vaginal sonography in identifying benign and malignant tumors was 82%, and the specificity, 92%. None of the unilocular tumors was malignant. Papillary formations on the inside of the cyst wall indicated an increased chance of the tumor's being malignant. There was a clear correlation between size of tumor and malignancy except for unilocular tumors. Vaginal sonography was shown to be accurate in characterizing cystic tumors in the lower pelvis. The present results also indicate that the probability that unilocular tumors less than 10 cm in diameter and without papillary formations, are malignant is low, irrespective of the woman's age.

Adult↗
PubMed1990

Bradykinin induces contractions of the human ovarian follicular wall in vitro.

Bradykinin has been shown to have a positive modulatory role in the ovulatory process. In the present study, the contractile properties elicited by bradykinin (10(-12)-10(-5) M) in the isolated human follicular wall were examined. Strips from the follicular base and apex were mounted separately and superfused at 37 degrees C with oxygenated HEPES buffer in tissue chambers. The contractile activity was recorded isometrically by a force transducer (Grass model FT03), under a passive tension of 5 mN. Preovulatory follicles (cycle day 10-14) were more sensitive to bradykinin than follicles of an earlier developmental stage (cycle day 1-9). The response to bradykinin was not altered by the addition of indomethacin (10(-7) M), atropine (10(-6) M) or phenoxybenzamine (10(-7) M). These data suggest that the contraction caused by bradykinin is a specific effect, which, under physiological conditions, might contribute to the ovulatory process by inducing a rise in tone in the follicle thereby facilitating the extrusion of the oocyte through the digested follicular apex.

Adult↗
PubMed1990

Contractile effect of oxytocin and 1-deamino-1-carba-2-tyrosine (0-methyl)-oxytocin in myometrial tissue from non-pregnant and term pregnant women.

The contractile effect of the analogue 1-deamino-1-carba-2-tyrosine (0-methyl)-oxytocin (carbetocin) on isolated strips from the human myometrium was compared with that of oxytocin. Neither oxytocin nor carbetocin affected contractile activity in strips from non-pregnant women, but both peptides stimulated contractile activity in strips from women at term pregnancy (2 x 10(-11) mol/l, and 10(-10) mol/l, respectively). Thus, carbetocin is almost as potent as oxytocin with regard to stimulating myometrial contractions at term.

Adult↗
PubMed1990

Influence of neurohypophyseal hormones on human cervical smooth muscle contractility in vitro.

Cervical tissue strips from nonpregnant women and women in early and term pregnancy were used to study spontaneous contractile activity and the effects of oxytocin and vasopressin in vitro. Oxytocin stimulated contractions in strips from all groups of patients except for those from five term pregnant women, in which an inhibitory effect was observed at a high concentration. Vasopressin had a stimulatory effect in all groups of patients. These neurohypophyseal hormones may interact with the effect of other hormones in their regulatory influence on cervical contractility, and this interaction might be important in cervical dilatation during labor as well as in the pathophysiology of dysmenorrhea.

Adult↗
PubMed1989

Histochemical localization of vasoactive intestinal polypeptide and its influence on contractile activity in the non-pregnant and pregnant human cervix.

The distribution of vasoactive intestinal peptide (VIP) was studied by immunofluorescence in cervical tissue of non-pregnant and pregnant women. VIP was localized in connection with blood vessels as well as among collagen fibres and smooth muscle cells. No difference was observed between non-pregnant and term pregnant women. The effect of VIP on cervical contractility was tested on isolated strips by superfusion in a tissue chamber. VIP inhibited contractions at 10(-8)-10(-6) M concentration, strips from term pregnant women responding more frequently at the lower concentration. It is suggested that VIP-containing neurons of the human cervix remain intact throughout pregnancy until term.

Animals↗
PubMed1989

Uptake of 3H-norepinephrine in different segments of the human non-pregnant and pregnant uterus.

Tissue specimens from uterine cervix and corpus of non-pregnant and pregnant women were incubated in vitro in the presence of 3H-norepinephrine. The uptake in the cervix exceeded those of the lower and upper segments of the corpus, and this difference was most pronounced at term pregnancy. The neuronal uptake in the cervix constituted approximately 80% of the total uptake and was higher than in isthmus and fundus (50 and 20%, respectively). The results favour the notion that cervical nerves remain functionally intact throughout pregnancy and support previous histochemical studies demonstrating a segmental difference in uterine innervation and a partial denervation of the myometrium at term.

Cervix Uteri↗
PubMed1988

Cervical dilatation by Lamicel before first trimester abortion: a clinical and experimental study.

Twenty women were treated with Lamicel tents for 4 h and 20 women for 16 h before vacuum aspiration in the first trimester of pregnancy. The shorter time of treatment was as effective as the longer time with respect to cervical softening and dilatation. In comparison with an untreated control group, Lamicel treatment was followed by an increased collagenolytic activity and increased sensitivity to prostaglandin E2 of the cervical smooth muscle.

Abortion, Therapeutic↗
PubMed1988

Response of isolated muscle of the human cervix to electrofield stimulation.

Contractile activity was registered isometrically in isolated strip biopsies from the uterine cervix of nonpregnant, early pregnant and term pregnant women, and the influence of electrofield stimulation (EFS) was studied. In the great majority of women an excitatory effect was observed, but occasionally an inhibitory response occurred. The excitatory effect of EFS was reduced and, in many cases, changed to inhibition during treatment with guanethidine and phenoxybenzamine. These inhibitory effects were not antagonized by treatment with propranolol, indicating that the responses were not mediated by beta-adrenoceptors. Tetrodotoxin reduced or abolished the excitatory effect of EFS. The data suggest that contractile activity of the human cervix is influenced by both adrenergic and nonadrenergic neurons, which remain intact throughout pregnancy. This innervation may be a central part of neuromuscular control systems which undergo important adaptive changes during pregnancy and in connection with parturition.

Cervix Uteri↗
PubMed1988

Reduced incidence of postoperative endometritis by the use of Laminaria tents in connection with first trimester abortion.

A Laminaria tent was inserted in the cervical canal of 115 primigravidae prior to vacuum aspiration in the first trimester. A mean dilatation of 9.7 mm was thereby achieved. Only 2 of these patients were treated by antibiotics due to 'mild' endometritis, as compared with 10 of 130 control patients due to endometritis and 7 patients due to 'mild' endometritis. Three non-treated control patients had to undergo laparoscopy due to perforation of the uterus during dilatation of the cervical canal. It is concluded that pre-treatment with the Laminaria tent prior to vacuum aspiration reduces the incidence of per- and post-operative complications.

Abortion, Induced↗
PubMed1988

Determination of specific mercapturic acids in human urine after experimental exposure to toluene or o-xylene.

Volunteers were exposed to toluene and o-xylene for 4 h at 300 mg/m3 and 350 mg/m3, respectively, in an exposure chamber. Urine voided during and after the exposure was analysed for S-benzyl-N-acetylcysteine (toluene mercapturic acid) and S-(o-methylbenzyl)-N-acetylcysteine (o-xylene mercapturic acid). The amount of S-(o-methylbenzyl)-N-acetylcysteine found in urine after exposure corresponded to a metabolic yield of less than about 0.01% of the total uptake. No S-benzyl-N-acetylcysteine was found. Thus, determination of specific mercapturic acids after exposure to toluene or o-xylene can hardly be used for genotoxic monitoring.

Acetylcysteine↗
PubMed1987

On the specificity of prostaglandin and steroid induced inhibition of 3H-proline incorporation in the human follicular wall.

Experiments were carried out to elucidate whether the previously reported inhibitory effect of prostaglandin (PG) E2 on 3H-proline incorporation into total protein of specimens from the isolated preovulatory human follicular wall could be exerted also by other prostanoids. Moreover, investigations were designed to explore if the previously documented inhibitory effect of steroids on 3H-proline incorporation could be mediated by endogenously formed PGs. Tissue specimens from the apical wall of follicles were incubated in the presence of PGF2 alpha, 6-keto-PGF1 alpha, progesterone (P) or 17 beta-estradiol (E2). The steroids were added alone or in combination with the PG synthetase blockers, indomethacin or 5, 8, 11, 14-eicosatetraynoic acid. Following incubation with 3H-proline for 2-4 h, the incorporated radioactivity was determined. PGF2 alpha and 6-keto-PGF1 alpha had no effect on 3H-proline incorporation. Both P and E2 induced a significant decrease of 3H-proline incorporation in preovulatory follicles, whereas similar effects in unripe follicles were statistically significant only for P. The steroid effects were not influenced when blockers of PG synthesis were added concomitantly. It is concluded that among the "classical" PGs PGE2 has a unique effect on collagen metabolism in the human follicular wall. E2 and especially P have a similar inhibitory effect on collagen formation as reflected by measurements of 3H-proline incorporation, an effect which does not appear to be primarily mediated by endogenous PGs.

Collagen↗
PubMed1987

Occupational exposure to chain saw exhausts in logging operations.

The composition of exhaust emissions from two-stroke chain saw engines was studied. The emissions of exhaust were sampled and analyzed under controlled laboratory experiments. The compounds sampled were those considered primarily responsible for acute health effects--hydrocarbons, aldehydes, nitrogen oxides and carbon monoxide. Exposure to tetramethyllead, dibromoethane and polycyclic aromatic hydrocarbons also was monitored. The results revealed no significant differences in the exhaust emissions from seven different chain saws. Heavily worn-out chain saws do not emit increased amounts of exhaust. A lean fuel-air mixture increases the emission of aldehydes and nitrogen oxides, whereas a rich mixture increases emission of carbon monoxide and hydrocarbons. Based on these new data on the composition of two-stroke chain saw exhaust emissions, operator exposure to chain saw exhaust was evaluated under various logging situations. Exposure measurements revealed no difference in average levels of exposure between logging in the presence or in the absence of snow. The felling operation, however, results in high exposure levels of short duration--especially when the operation is performed while there is deep snow on the ground. (This operation excludes limbing and bucking into lengths.) This is judged to be the main cause of the discomfort experienced by loggers. Average exposure levels for loggers engaged only in felling are twice those for cutters who also perform limbing, bucking and manual skidding of the timber, since these latter operations involve considerably lower exposure. Typical average levels of exposure are as follows: hydrocarbons, 20 mg/m3; benzene, 0.6 mg/m3; formaldehyde, 0.1 mg/m3; and carbon monoxide, 20 mg/m3.

Air Pollutants, Occupational↗
PubMed1987

Immunohistochemical evidence for preserved innervation of the human cervix during pregnancy.

Morphological evidence for a denervation of the human myometrium during pregnancy has previously been demonstrated. In the present study the innervation of the human cervix has been investigated in nonpregnant, early pregnant and term pregnant women. An indirect immunofluorescence method, using an antiserum to the Schwann cell specific S-100 protein, was applied to document the distribution of nerve fibers in cervical tissue biopsies. In nonpregnant, as well as in pregnant women, the cervix was by far more densely innervated than the rest of the uterus. No obvious difference in nerve density was observed between nonpregnant, early pregnant and term pregnant women, and still during labor the innervation appeared morphologically preserved. It is suggested that the segmental difference in innervation of the human uterus (corpus versus cervix) may have specific importance for myometrial and cervical contractility during pregnancy and parturition.

Adult↗
PubMed1986

Oxytocin in human follicular fluid and its possible role in the ovulatory process as studied in vitro.

Oxytocin immunoreactivity was determined in follicular fluid from human follicles at different stages of development. The concentration of oxytocin was highest in pre-ovulatory follicles. The measured oxytocin was found to co-elute with synthetic oxytocin in an h.p.l.c. system. The influence of oxytocin on the incorporation of [3H]proline into isolated human follicular wall was studied in vitro. Oxytocin induced a decrease of radiolabelling in both unripe and pre-ovulatory follicles, indicating an inhibitory effect on collagen synthesis. This effect of oxytocin was not affected by indomethacin. An oxytocin analogue, 1-deamino-2-D-Tyr(OEt)-4-Thr-8-Orn-vasotocin, did not inhibit the incorporation of [3H]proline. The pre-ovulatory augmentation of oxytocin concentration in follicular fluid might reflect a physiological role for oxytocin in the ovulatory process. This assumption is strengthened by the observation that oxytocin may influence follicular collagen metabolism in vitro and by this means participate in the regulation of follicular rupture in the human.

Adult↗