Claus Otto Lund

Publications (3)7.95 Total impact

• Article: Tibolone and its metabolites acutely relax rabbit coronary arteries in vitro.

  Claus Otto Lund, Lisbeth Nilas, Susan Helene Pedersen, Tórur Dalsgaard, Bent Ottesen
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  ABSTRACT: To compare the acute effects of estradiol, tibolone and its metabolites on coronary arteries in vitro and to investigate possible vascular mechanisms. Coronary artery ring segments from female rabbits were mounted in myographs for isometric tension recordings. Concentration-response curves to tibolone, 3 alpha-OH-tibolone, 3 beta-OH-tibolone, Delta 4-isomer and 17 beta-estradiol were obtained after precontraction with potassium 30 mmol/l and after addition of N omega-nitro-l-arginine methyl ester 10(-4) mol/l (l-NAME, an inhibitor of endothelial nitric oxide (NO) synthase) or tetraethylammonium chloride 10(-2) mol/l (TEA, an unspecific inhibitor of potassium channels). The effects of the different substances to calcium concentration-response curves were evaluated. Responses are expressed as maximal contraction (E max), concentration giving half maximal contraction (log EC50) or area under curve (AUC). Tibolone and its metabolites induced a concentration-dependent vasodilatation comparable to that of 17 beta-estradiol with the rank of potency: 3 beta-OH-tibolone approximately = to tibolone>3 alpha-OH-tibolone>Delta 4-isomer (ANOVA). l-NAME partly inhibited the relaxation to all substances. TEA induced a slight rightward shift of the relaxation to 3 alpha-OH-tibolone (log EC50: -5.05 versus -5.20; P<0.05; Student's t-test), but not to the other substances. Calcium concentration-dependent contraction curves were inhibited by all substances compared to controls (AUC, P<0.05, ANOVA). Our data indicate that the acute relaxation induced by tibolone and its metabolites in coronary arteries in vitro are probably mediated by endothelium independent inhibition of calcium channels but may also involve an endothelium-dependent mechanism via nitric oxide. The effect of tibolone is comparable to that of 17 beta-estradiol in this set-up.
  Maturitas 12/2004; 49(3):179-88. · 2.77 Impact Factor
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  Available from: stanford.edu

  Article: Improved fertility following conservative surgical treatment of ectopic pregnancy.

  Nannie Bangsgaard, Claus Otto Lund, Bent Ottesen, Lisbeth Nilas
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  ABSTRACT: To evaluate fertility after salpingectomy or tubotomy for ectopic pregnancy. Retrospective cohort study. Clinical University Center, Hvidovre Hospital, Copenhagen. Two hundred and seventy-six women undergoing salpingectomy or tubotomy for their first ectopic pregnancy between January 1992 and January 1999 and who actively attempted to conceive were followed for a minimum of 18 months. Retrospective cohort study combined with questionnaire to compare reproductive outcome following salpingectomy or tubotomy for ectopic pregnancy. Cumulative probabilities of pregnancy for each group were calculated by the Kaplan-Meier estimator and compared by Cox regression analysis to control for potential confounders. Intrauterine pregnancy rates and recurrence rates of ectopic pregnancy after surgery for ectopic pregnancy. The cumulative intrauterine pregnancy rate was significantly higher after tubotomy (88%) than after salpingectomy (66%) (log rank P < 0.05) after correction for confounding factors. No difference was found in the recurrence rate of ectopic pregnancy between the treatments (16% vs 17%). In patients with contralateral tubal pathology, the chance of pregnancy was poor (hazard ratio 0.463) and the risk of recurrence was high (hazard ratio 2.25), assessed with Cox regression. The rate of persistent ectopic pregnancy was 8%. Conservative surgery is superior to radical surgery at preserving fertility. Conservative surgery is not followed by an increased risk of repeat ectopic pregnancy, but by the risk of persistent ectopic pregnancy, which should be taken into account when deciding on the operative procedure. Management in case of contralateral tubal pathology is disputed and should ideally be addressed in a randomised clinical trial.
  BJOG An International Journal of Obstetrics & Gynaecology 08/2003; 110(8):765-70. · 3.41 Impact Factor
• Article: Persistent ectopic pregnancy after linear salpingotomy: a non-predictable complication to conservative surgery for tubal gestation.

  Claus Otto Lund, Lisbeth Nilas, Nannie Bangsgaard, Bent Ottesen
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  ABSTRACT: The drawback of conservative surgery for ectopic pregnancy (EP) is the risk of persistent trophoblast. The purpose was to characterize patients who develop persistent ectopic pregnancy (PEP) after salpingotomy for EP and to assess prognostic factors. The medical records of 417 patients treated by salpingotomy for EP were reviewed. Forty-eight (11.5%) patients were diagnosed with persistent EP. The data were analyzed using the Mann-Whitney U-test, Fischer's exact test or the chi2-test. Of 417 women, 48 (11,5%) were treated for PEP by either repeat surgery (n = 25) or methotrexate (n = 23). Oral methotrexate failed in 4/19 cases while intramuscular (i.m.) methotrexate was successful in 4/4 cases. Women treated for PEP had a higher preoperative and a slower postoperative decline of serum human chorionic gonadotropin (hCG). Both the preoperative and the early postoperative hCG levels had a low diagnostic sensitivity (0.38-0.66) and specificity (0.74-0.77) for predicting PEP. In multivariate logistic analysis, none of the following clinical variables were predictive of PEP: duration of surgery, laparoscopic approach, history of previous EP, history of previous lower abdominal surgery, ruptured EP, pelvic adhesions, absence of products of conception at microscopy and hemoperitoneum. Persistent ectopic pregnancy can neither be predicted from clinical variables nor from single measurements of hCG with an accuracy sufficient for clinical use.
  Acta Obstetricia Et Gynecologica Scandinavica 12/2002; 81(11):1053-9. · 1.77 Impact Factor