Isosorbide mononitrate induces increased cervical expression of cyclooxygenase-2, but not of cyclooxygenase-1, at term.

OBJECTIVE: Prostaglandin and nitric oxide (NO) are both known to be involved in cervical ripening at term. The aim of the study was to investigate if NO has an effect on cervical expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), the two main isoenzymes involved in prostaglandin synthesis, and to localize these enzymes within the cervix. STUDY DESIGN: Women with an unripe cervix scheduled for elective caesarean section at term were randomly selected to receive vaginally either the NO donor isosorbide mononitrate (IMN) or placebo 4h before surgery. At the operating theatre, cervical tissue specimens were obtained for immunoblotting and immunohistochemistry. RESULTS: Increased expression of COX-2 was found in specimens exposed to IMN compared to specimens obtained from women in the placebo group. There was no difference in the expression of COX-1. Immunohistochemistry revealed similar localization of the two enzymes in treated and untreated women. CONCLUSIONS: Vaginal administration of IMN induces increased cervical expression of COX-2, but not of COX-1. This pathway may be of importance in the process of cervical ripening at term.

Sublingual nitroglycerin for management of retained placenta.

OBJECTIVE: The aim of the study was to investigate the effect of sublingual nitroglycerin for management of retained placenta and to assess possible adverse effects of the treatment. METHOD: Twenty-four women were randomly selected to receive either 1 mg nitroglycerin or placebo tablets sublingually if intravenous oxytocin and controlled umbilical cord traction had failed to expel the placenta. Success rate for delivery of placenta, blood pressure, pulse rate, blood loss, and various side effects were examined. RESULT: All 12 women in the nitroglycerin group had successful delivery of placenta, while removal of placenta was successful in only one of the 12 women in the placebo group. No adverse effects of clinical importance were registered. CONCLUSION: Sublingual nitroglycerin for treatment of retained placenta seems to be effective without causing serious adverse effects. However, the definite clinical value needs to be evaluated in larger series of patients.

Involvement of a nitric oxide-cyclic guanosine monophosphate pathway in control of fallopian tube contractility.

Fallopian tube smooth muscle contractions are physiologically related to transport of the ovum within the oviduct. Nitric oxide (NO) has proved to be a mediator of tubal contractility. The main pathway by which NO exerts its relaxing effect on tubal contractions has not been fully elucidated. NO-mediated effects may be cyclic guanosine monophosphate (cGMP)-dependent or cGMP-independent. The objective of the present study was to investigate whether a NO-cGMP pathway is present in the Fallopian tube and, if present, to examine whether this pathway is involved in tubal contractility. Tubal smooth muscle strips were mounted in organ baths for measurement of tissue cGMP and for isometric recording of contractile activity. Following administration of the NO donor spermine NONOate a more than three-fold increase in tissue levels of cGMP was measured. Pretreatment with inhibitors of cGMP production prior to administration of spermine NONOate resulted in similar levels of cGMP as found in strips exposed to only plain buffer solution. Administration of spermine NONOate to muscle baths resulted in a significant inhibition of contractile activity, while pretreatment with inhibitors of cGMP production almost eliminated the relaxing effect of the NO donor. This study showed that a NO-cGMP pathway is present in the Fallopian tube and that the pathway is involved in Fallopian tube contractility.

Gemeprost versus misoprostol for cervical priming before first-trimester abortion: a randomized controlled trial.

OBJECTIVE: To compare the efficacy of 400 microg of misoprostol with that of 1 mg of gemeprost as cervical priming agents when administered vaginally 3 to 4 hours before first-trimester vacuum aspiration abortion. METHODS: In a prospective controlled trial 90 nulliparous women who requested termination of pregnancy before 12 weeks' gestation were randomized to receive vaginally either misoprostol or gemeprost for cervical priming. The force to dilate the cervix was measured by the use of a cervical tonometer connected to Hegar dilators from 3 to 10 mm. The main outcome measures were baseline cervical dilation; the peak force to dilate the cervix at 8, 9, and 10 mm; and the cumulative force to dilate the cervix to 10 mm. RESULTS: Baseline cervical dilation did not differ significantly between the women who received misoprostol and those who were treated with gemeprost. Neither the peak force required to dilate the cervix at 8, 9, and 10 mm nor the cumulative force to dilate the cervix to 10 mm showed any significant difference between the two groups. CONCLUSION: Vaginally administered misoprostol (400 microg) is as effective as gemeprost (1 mg) for cervical priming 3 to 4 hours before surgical termination of first-trimester pregnancies.

Nitric oxide induced cervical ripening in the human: Involvement of cyclic guanosine monophosphate, prostaglandin F(2 alpha), and prostaglandin E(2).

OBJECTIVE: The purpose of the study was to investigate possible mechanisms and morphologic changes involved in nitric oxide-induced cervical ripening. STUDY DESIGN: Women scheduled for surgical termination of first trimester pregnancy were randomized to 1 of 3 groups: isosorbide 5-mononitrate 40 mg 4 hours or 10 hours before the operation or no preoperative treatment. Cervical specimens were obtained for the analysis of tissue levels of cyclic guanosine monophosphate, cyclic adenosine monophosphate, cyclo-oxygenase 1, cyclo-oxygenase 2, prostaglandin F(2 alpha), and prostaglandin E(2) or were fixed in glutaraldehyde for microscopy. RESULTS: Increased levels of cyclic guanosine monophosphate, cyclo-oxygenase 2, prostaglandin F(2 alpha), and prostaglandin E(2) were found in samples that were exposed to isosorbide 5-mononitrate compared with control samples. Electron microscopy revealed stromal edema and collagen disorganization after isosorbide 5-mononitrate treatment. CONCLUSION: Cyclic guanosine monophosphate, prostaglandin F(2 alpha), and prostaglandin E(2) are involved in nitric oxide-induced cervical ripening. Nitric oxide causes morphologic changes similar to those changes seen during spontaneous cervical ripening.

Serial ultrasonography, hormonal profile and antisperm antibody response after testicular sperm aspiration.

BACKGROUND: In many fertility centres, intracytoplasmic sperm injection (ICSI) with epididymal or testicular spermatozoa is a routine treatment for men with azoospermia. In this prospective study, the physiological consequences after testicular sperm aspiration (TESA), using suction and a 19 gauge needle, were evaluated. METHODS AND RESULTS: Thirty-five consecutive men with azoospermia underwent TESA. Testicular ultrasonography with Doppler flow imaging was performed and testicular volumes were evaluated pre-operatively and 3 months after aspiration. If focal testicular lesions were found, further examinations were performed 6 and 9 months after TESA. Serum FSH, testosterone and antisperm antibodies (ASA) were analysed. Focal testicular lesions were seen in four out of 61 testes (6.6%) at the 3 month investigation point. Three lesions were resolved after 6 months and all after 9 months. Testicular echogenicity remained unchanged in 50 cases (82%) 3 months after TESA. Four men (11.4%) reported severe subjective discomfort post-operatively, but only one had a medical consultation where an intratesticular haematoma was diagnosed. There were no significant changes in FSH and testosterone after surgery and testicular volumes were similar after 3 months. There were three borderline cases of ASA in serum, but none was classified as ASA-positive. CONCLUSIONS: The puncture method of testicular sperm aspiration seems to be a safe method for sperm retrieval, with minimal physiological consequences.

Plasma concentrations of nitrate during the menstrual cycle, ovarian stimulation and ovarian hyperstimulation syndrome.

BACKGROUND: Nitric oxide (NO) is predominantly a locally acting mediator, affecting several functions in the human female reproductive tract. In vivo, it is quickly metabolized to its stable end product nitrate, which is cleared by the kidney. METHODS AND RESULTS: The aim of the present study was to evaluate possible fluctuations of plasma nitrate concentrations during the menstrual cycle, ovarian stimulation as well as ovarian hyperstimulation syndrome (OHSS). During the menstrual cycle (n = 19 women) the mean nitrate concentrations were between 26.7 and 29.5 micromol/l at all stages except for the day of ovulation, when the concentrations were significantly (P < 0.001) increased (mean 37.2 micromol/l +/- 2.0). Significantly lower concentrations of plasma nitrate (P < 0.01) were measured at the end of gonadotrophin-releasing hormone (GnRH) down-regulation (24.6 micromol/l +/- 1.4) compared with the concentrations found at day 8 of follicle-stimulating hormone (FSH) stimulation (34.9 micromol/l +/- 2.6) and at the day of human chorionic gonadotrophin (HCG) (35.6 micromol/l +/- 3.3). The concentrations of nitrate (33.4 micromol/l +/- 3.4) in women with OHSS (n = 13) were similar to those seen 5 days after embryo transfer (33.2 micromol/l +/- 2.3). CONCLUSIONS: The results indicate that NO synthesis is increased at the time of spontaneous ovulation. GnRH treatment inhibits NO synthesis, while NO production is not increased in women with OHSS.

Testicular ultrasonography and extended chromosome analysis in men with nonmosaic Klinefelter syndrome: a prospective study of possible predictive factors for successful sperm recovery.

OBJECTIVE: To investigate whether extended chromosome analysis or testicular sonography, including flow Doppler imaging, before diagnostic testicular sperm extraction have predictive value for successful sperm retrieval in men with nonmosaic Klinefelter syndrome. DESIGN: Prospective clinical study. SETTING: IVF clinic and genetics laboratory at a university hospital. PATIENT(S): Nineteen patients with nonmosaic Klinefelter syndrome and azoospermia. INTERVENTION(S): Collection of blood samples; histopathologic examination of testicular tissue; fluorescence in situ hybridization; sonography, including Doppler imaging; and testicular sperm extraction. MAIN OUTCOME MEASURE(S): Testicular volume, serum FSH and serum testosterone levels, percentage of normal XY cells, ultrasound echogenicity, intratesticular blood flow resistance, and sperm recovery. RESULT(S): Testicular volume and levels of serum FSH and serum testosterone levels did not differ significantly. No differences in testicular echogenicity or intratesticular blood flow resistance were found between 47,XXY men in whom sperm recovery was successful and those in whom sperm recovery failed. Significant differences were seen between all patients with the Klinefelter syndrome and controls with normal sperm values. Fluorescence in situ hybridization of peripheral lymphocytes and buccal tissue showed no correlation between frequency of normal 46,XY cells and testicular spermatogenesis. CONCLUSION(S): In azoospermic men with the Klinefelter syndrome, histopathologic findings seem to be predictive for successful sperm recovery. Infertility work-up, including diagnostic testicular sperm recovery, is recommended, and, if possible, viable sperm should be cryopreserved.

Preoperative assessment of unilocular adnexal cysts by transvaginal ultrasonography: a comparison between ultrasonographic morphologic imaging and histopathologic diagnosis.

OBJECTIVE: Our purpose was to evaluate the risk of malignancy in surgically removed ovarian cysts that were characterized before the operation as unilocular according to transvaginal ultrasonography. STUDY DESIGN: This prospective analysis included 927 premenopausal women and 377 postmenopausal women operated on at 2 European university hospitals between January 1992 and December 1997. On the basis of ultrasonographic findings the cysts were characterized either as echo-free, without solid parts or papillary formations (group 1), or as having echogenic cyst content, with solid parts or papillary formations (group 2). Ultrasonographic and macroscopic appearances of the cysts were compared with histopathologic diagnosis. RESULTS: In group 1, in premenopausal women 3 of 413 cysts (0.73%) proved to be borderline or malignant, and in postmenopausal women 4 of 247 cysts (1.6%) proved to be borderline or malignant. The figures for cysts in group 2 were 11 of 514 cysts (2.1%) and 13 of 130 cysts (10.0%), respectively. It was not possible to differentiate by transvaginal ultrasonography between benign, borderline, and malignant cysts when solid parts or papillary formations were visualized. CONCLUSIONS: This study confirmed that the risk of malignancy associated with unilocular echo-free cysts (group 1) was low. Serial ultrasonographic follow-up should therefore be the standard procedure with unilocular echo-free cysts <50 mm in diameter. In cysts with a mean diameter of >50 mm, papillary formations or solid parts may be missed by transvaginal ultrasonography. The risk for malignancy in cysts containing papillary formations or solid parts (group 2) was 3 to 6 times higher than that in unilocular echo-free cysts.

Nitric oxide synthases in the human cervix at term pregnancy and effects of nitric oxide on cervical smooth muscle contractility.

OBJECTIVE: The purpose of the study was to determine whether a nitric oxide-generating system exists in the uterine cervix at term pregnancy and to study the effects of nitric oxide on contracting cervical strips. STUDY DESIGN: Tissue specimens were obtained from the cervices of women after deliveries and at elective cesarean deliveries. Immunohistochemical techniques and immunoblotting were used to identify isoforms of nitric oxide synthase. The effects of nitric oxide on cervical contractility were examined by the addition of nitroglycerin or spermine NONOate [(Z)-1-(N -[3-aminopropyl]-N -[4-(3-aminopropyl-ammonio)butyl]-amino)-diazen-1-ium-1,2-++ +diolate] to organ baths. RESULTS: Immunohistochemical examination demonstrated positive staining for both endothelial and inducible nitric oxide synthase. Both isoforms of nitric oxide synthase were clearly detectable by immunoblotting. Significant inhibition of contractile activity (10(-7)-10(-5) mol/L) was observed when nitroglycerin or spermine NONOate was administered. CONCLUSION: An endogenous nitric oxide system is present in the uterine cervix at term, and this tissue is responsive to nitric oxide, which causes relaxation of the cervical muscle.

Localization of nitric oxide synthase and effects of nitric oxide donors on the human Fallopian tube.

The objective of the study was to assess the plausible existence of a nitric oxide (NO) system within the human Fallopian tube and to examine the effects of NO on tubal contractility. Tissue was obtained from fertile women at operations due to non-tubal diseases. Production of NO and sites of nitric oxide synthase (NOS) activity were assessed by the use of NADPH diaphorase staining and by immunoblots as well as immunohistochemistry for the isoforms of NOS. Effects of NO on tubal contractility in vitro were examined by adding either of two NO donors (nitroglycerin, spermine NONOate) or an analogue of its second messenger (8-bromo cyclic GMP). The production of NO was indicated by positive NADPH diaphorase staining. In immunoblots, endothelial and inducible NOS were demonstrated in all samples analysed. By immunohistochemistry, moderate staining for endothelial NOS was demonstrated in the luminal epithelial cells and in the endothelial cells of blood vessels. Moderate staining for inducible NO synthase was seen in smooth muscle cells and weak staining in epithelial cells. Nitroglycerin, spermine NONOate and 8-bromo cGMP all resulted in a concentration-dependent inhibition of contractility with significant contractility inhibition at 10(-7) mol/l, 10(-6) mol/l and 10(-5) mol/l respectively. The study demonstrates the existence of an endogenous NO system, which may be of physiological importance in Fallopian tube function.

Nitric oxide-mediated effects on myometrial contractility at term during prelabor and labor.

OBJECTIVE: To assess the existence of a nitric oxide (NO) system in the human myometrium and the effects of mediators of this system on contractile activity in vitro. METHODS: Myometrial tissue was obtained before the onset of labor and during labor at term. Production of NO was assessed by the use of nicotinamide dinucleotide phosphate diaphorase staining and by immunoblots for NO. Effects of NO were examined by adding L-arginine (the substrate for NO synthesis); N(G)-nitro-L-arginine methyl ester (an inhibitor of NO synthase); two NO donors, sodium nitroprusside and spermine NONOate; as well as 8-bromo cyclic guanosine monophosphate (8-bromo cGMP) (a second messenger analogue) to organ baths. RESULTS: Myometrial NO production was indicated by positive nicotinamide adenine dinucleotide phosphate diaphorase staining. Immunoblots detected endothelial NO synthase, whereas only a weak signal for inducible NO synthase was seen. The addition of L-arginine (10(-4)-10(-3) mol/L) did not result in any change of contractility. N(G)-nitro-L-arginine methyl ester (10(-3) mol/L) caused a minor increase of contractility in half of the specimens. Sodium nitroprusside, spermine NONOate, and 8-bromo cGMP resulted in a concentration-dependent inhibition of contractility (10(-7)-10(-6) mol/L for sodium nitroprusside, 10(-6)-10(-5) mol/L for spermine NONOate, and 10(-5)-10(-3) mol/L for 8-bromo cGMP). However, at 10(-5)-10(-4) mol/L, sodium nitroprusside exhibited a dose-dependent increase in the frequency of contractions. Women in prelabor did not differ from those in active labor. CONCLUSION: The myometrium produces NO at term. Nitric oxide inhibits myometrial contractile activity. The responsiveness to NO is similar in nonlaboring and laboring women.

Nitric oxide mediated inhibition of contractile activity in the human uterine cervix.

Nitric oxide (NO) is an important modulator of contractile activity in various tissues. The aim of the present study was to investigate the possible existence of an NO system within the human uterine cervix and to study the effects of NO on the cervix in early pregnancy. Cervical tissue specimens were obtained from 24 women in connection with first trimester legal abortion. NADPH diaphorase staining was used to identify nitric oxide synthase activity within the cervical tissue. Cylindrical tissue specimens were mounted in organ bath chambers for isometric registration of contractile activity. The presence of a functional NO system in the cervix was investigated by adding either sodium nitroprusside or spermine NONOate, two different NO donors, or 8-bromo cGMP, an analogue of the second messenger cyclic guanosine monophosphate (cGMP), to the organ baths. Positive NADPH diaphorase staining was clearly observed in the walls of blood vessels, in cervical smooth muscle cells, and cells scattered in the connective tissue. The NO donating drugs sodium nitroprusside and spermine NONOate both caused a dose-dependent inhibition of spontaneous contractile activity with significant inhibition at concentrations of 10(-5) and 10(-7) M respectively. Furthermore, the participation of NO in the regulation of cervical contractility was indicated by a significant concentration-dependent inhibition of spontaneous contractions when 8-bromo cGMP (10(-5)-10(-3) M) was added to the organ baths. The study indicates the existence of an NO system within the human uterine cervix and a role of NO in control of cervical function.

Evidence for nitric oxide mediation of contractile activity in isolated strips of the human Fallopian tube.

Endogenously produced nitric oxide (NO) induces relaxation in smooth muscle in various organs. The purpose of this study was to investigate whether a NO-mediated relaxation system exists in the human Fallopian tube. To study contractility, the isthmic portion of the tube was obtained from 23 fertile women during operations due to benign non-tubal diseases. Tubal smooth muscle strips were mounted in tissue chambers containing HEPES buffer and connected to a Grass transducer for the isometric registration of contractile activity. By adding L-arginine (the substrate for NO synthesis) or N-nitro-L-arginine methyl ester (L-NAME; an inhibitor of NO synthesis) to the tissue chambers, changes in tubal contractility were monitored. The addition of L-NAME caused increased tubal contractility, while L-arginine, after an initial transient increase in tonus, caused relaxation of the strips. Using immunohistochemistry, NO synthase, the enzyme that catalyses the production of NO from L-arginine, was identified in tubal tissue cells. These results indicate that a NO-dependent relaxation system exists in the Fallopian tube and that NO may play a role as a mediator of tubal contractility.