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1.
Acta Obstet Gynecol Scand ; 103(2): 368-377, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38031442

RESUMO

INTRODUCTION: The Medtronic Hugo™ Robot-assisted Surgery (RAS) system was recently approved for clinical use. We explored the safety and feasibility of this system for endometriosis surgery. The primary outcome was safe case completion without major surgical complications (Clavien-Dindo grade ≤2) and no conversion to open surgery or laparoscopy. MATERIAL AND METHODS: Surgeries for endometriosis performed at the Department of Gynecology, Rigshospitalet, on the Medtronic Hugo™ RAS system were included. Two experienced robotic surgeons performed all surgeries with their usual robotic team. The variables included were patient demographics, peri- and postoperative data, complications and 30-day readmission rate. We used the IDEAL framework 1/2a for surgical innovation in this descriptive study. RESULTS: The first 12 patients were included. All cases were completed without intraoperative complications or conversion. Four patients experienced Clavien-Dindo grade 1 postoperative complications. No patients were re-admitted within 30 days. Median docking time (17 minutes), console time (87.5 minutes), blood loss (40 mL) and length of hospital stay (1 day) were acceptable compared with previous literature. CONCLUSIONS: In this pilot study, we found the Medtronic Hugo™ RAS system safe and feasible for robot-assisted surgery for endometriosis. The advent of new robotic systems is welcomed to accelerate the development of technology that will advance surgical care for patients across the globe.


Assuntos
Endometriose , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Feminino , Humanos , Endometriose/cirurgia , Projetos Piloto , Laparoscopia/efeitos adversos
2.
Dan Med J ; 67(9)2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32800068

RESUMO

INTRODUCTION: Tonsillectomy is one of the most common procedures in the field of ear, nose and throat procedures. In 2012, the annual incidence in Denmark was 129.4 per 100,000 inhabitants. A common complication is post-tonsillectomy haemorrhaging (PTH). The overall PTH rates vary widely among studies ranging from 0.5% to 33%. METHODS: This was a nationwide open-population, retrospective and registry-based cohort study in Danes who underwent tonsillectomy complicated by PTH in hospitals and private otorhinolaryngology (ORL) offices in the period from 1991 to 2012. RESULTS: In the 1991-2012 period, a total of 177,211 tonsillectomies were performed among which 9,221 had a registered PTH (rPTH) (5.2%). The annual incidence rate of rPTH increased from 3% in 1991 to 13% in 2012 (p less-than 0.05). Males aged 20-40 years had a significantly higher risk of rPTH with the highest increase in rPTH incidence rates from 9.0% in 1998 to 16.4% in 2012 (p less-than 0.05). Approx. 12% had a primary rPTH within the first 24 hours; the maximum incidence of rPTH was on day six (14%). CONCLUSIONS: The rate of rPTH increased from 1991 to 2012 in hospitals and in private ORL office settings alike. There was a significantly higher rate of rPTH in the age group of 20-40 years and a significant geographical difference in rPTH. The highest risk of rPTH was observed on the day of surgery and on day six. TRIAL REGISTRATION: The Danish Data Protection Agency (record number 2012-41-0158) approved this study. FUNDING: The Olga Bryde Nielsen Foundation and H. Skouby & E. Skouby's Foundation supported this study financially.


Assuntos
Endometriose/terapia , Fertilização in vitro/métodos , Hormônio Liberador de Gonadotropina/agonistas , Procedimentos Cirúrgicos em Ginecologia/métodos , Infertilidade Feminina/terapia , Adulto , Coeficiente de Natalidade , Terapia Combinada , Dinamarca/epidemiologia , Regulação para Baixo , Endometriose/complicações , Feminino , Humanos , Infertilidade Feminina/etiologia , Laparoscopia , Nascido Vivo , Gravidez , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
3.
Int J Med Robot ; 16(5): 1-10, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32721072

RESUMO

BACKGROUND: The aim of this study was to design and validate a cross-specialty basic robotic surgical skills training program on the RobotiX Mentor virtual reality simulator. METHODS: A Delphi panel reached consensus on six modules to include in the training program. Validity evidence was collected according to Messick's framework with three performances in each simulator module by 11 experienced robotic surgeons and 11 residents without robotic surgical experience. RESULTS: For five of the six modules, a compound metrics-based score could significantly discriminate between the performances of novices and experienced robotic surgeons. Pass/fail levels were established, resulting in very few novices passing in their first attempt. CONCLUSIONS: This validated course can be used for structured simulation-based basic robotic surgical skills training within a mastery learning framework where the individual trainee can practice each module until they achieve proficiency and can continue training on other modalities and more specific to their specialty.


Assuntos
Procedimentos Cirúrgicos Robóticos , Treinamento por Simulação , Cirurgiões , Realidade Virtual , Competência Clínica , Simulação por Computador , Humanos
4.
Ann Surg ; 271(1): 106-113, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-29923873

RESUMO

OBJECTIVE: To study musculoskeletal workload in experienced surgeons during laparoscopic surgery (LS) compared with robotic assisted laparoscopy (RALS). BACKGROUND: 70-90% of surgeons who regularly perform LS report musculoskeletal symptoms, mainly in neck and shoulders. Data regarding the potential ergonomic benefits of RALS in a clinical setting is very limited. METHODS: Twelve surgeons with advanced experience in both LS and RALS each performed 2 hysterectomies on the same day. LS was performed standing, RALS sitting, the latter allowing forearm and head support. Bipolar surface electromyogram (EMG) was recorded from several muscles and was expressed relative to EMG during maximum contractions (%EMGmax). Gaps per minute plus static (p0.1), mean (p0.5), and peak (p0.9) muscle activation were calculated. Perceived exertion was rated before and just after each surgery. RESULTS: Neck muscle activity (p0.1 4.7 vs. 3.0%EMGmax, p0.5 7.4 vs. 5.3%EMGmax, p0.9 11.6 vs. 8.2%EMGmax, all P < 0.05) and static shoulder muscle activity (p0.1 5.7 vs. 2.8%EMGmax, P < 0.05) were higher for LS than for RALS. Both a higher level of gaps during RALS and a lower rating of perceived exertion, also for the legs, after RALS supported these observations. However, low back muscle activity was higher for RALS. CONCLUSIONS: RALS is significantly less physically demanding than LS, and also feels less strenuous for the surgeons. However, for both types of surgeries, there still is room for improvement of working conditions. To further optimize these, we suggest a scheme to regularly observe and advise the surgeons.


Assuntos
Esgotamento Profissional/prevenção & controle , Competência Clínica , Ergonomia/métodos , Laparoscopia/métodos , Músculo Esquelético/fisiopatologia , Procedimentos Cirúrgicos Robóticos/métodos , Cirurgiões/normas , Adulto , Idoso , Braço/fisiologia , Esgotamento Profissional/fisiopatologia , Estudos Transversais , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
J Robot Surg ; 13(1): 99-106, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29761352

RESUMO

Increasing focus on patient safety makes it important to ensure surgical competency among surgeons before operating on patients. The objective was to gather validity evidence for a virtual-reality simulator test for robotic surgical skills and evaluate its potential as a training tool. Surgeons with varying experience in robotic surgery were recruited: novices (zero procedures), intermediates (1-50), experienced (> 50). Five experienced surgeons rated five exercises on the da Vinci Skills Simulator. Participants were tested using the five exercises. Participants were invited back 3 times and completed a total of 10 attempts per exercise. The outcome was the average simulator performance score for the 5 exercises. 32 participants from 5 surgical specialties were included. 38 participants completed all 4 sessions. A moderate correlation between the average total score and robotic experience was identified for the first attempt (Spearman r = 0.58; p = 0.0004). A difference in average total score was observed between novices and intermediates [median score 61% (IQR 52-66) vs. 83% (IQR 75-91), adjusted p < 0.0001], as well as novices and experienced [median score 61% (IQR 52-66) vs. 80 (IQR 69-85), adjusted p = 0.002]. All three groups improved their performance between the 1st and 10th attempts (p < 0.00). This study describes validity evidence for a virtual-reality simulator for basic robotic surgical skills, which can be used for assessment of basic competency and as a training tool. However, more validity evidence is needed before it can be used for certification or high-stakes assessment.


Assuntos
Competência Clínica , Educação Médica/métodos , Avaliação Educacional/métodos , Procedimentos Cirúrgicos Robóticos/educação , Treinamento por Simulação , Cirurgiões/educação , Realidade Virtual , Feminino , Humanos , Masculino , Segurança do Paciente
6.
Surg Endosc ; 32(10): 4200-4208, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29603003

RESUMO

BACKGROUND: The use of robotic surgery for minimally invasive procedures has increased considerably over the last decade. Robotic surgery has potential advantages compared to laparoscopic surgery but also requires new skills. Using virtual reality (VR) simulation to facilitate the acquisition of these new skills could potentially benefit training of robotic surgical skills and also be a crucial step in developing a robotic surgical training curriculum. The study's objective was to establish validity evidence for a simulation-based test for procedural competency for the vaginal cuff closure procedure that can be used in a future simulation-based, mastery learning training curriculum. METHODS: Eleven novice gynaecological surgeons without prior robotic experience and 11 experienced gynaecological robotic surgeons (> 30 robotic procedures) were recruited. After familiarization with the VR simulator, participants completed the module 'Guided Vaginal Cuff Closure' six times. Validity evidence was investigated for 18 preselected simulator metrics. The internal consistency was assessed using Cronbach's alpha and a composite score was calculated based on metrics with significant discriminative ability between the two groups. Finally, a pass/fail standard was established using the contrasting groups' method. RESULTS: The experienced surgeons significantly outperformed the novice surgeons on 6 of the 18 metrics. The internal consistency was 0.58 (Cronbach's alpha). The experienced surgeons' mean composite score for all six repetitions were significantly better than the novice surgeons' (76.1 vs. 63.0, respectively, p < 0.001). A pass/fail standard of 75/100 was established. Four novice surgeons passed this standard (false positives) and three experienced surgeons failed (false negatives). CONCLUSION: Our study has gathered validity evidence for a simulation-based test for procedural robotic surgical competency in the vaginal cuff closure procedure and established a credible pass/fail standard for future proficiency-based training.


Assuntos
Competência Clínica/normas , Educação Baseada em Competências/métodos , Procedimentos Cirúrgicos em Ginecologia/educação , Ginecologia/educação , Procedimentos Cirúrgicos Robóticos/educação , Treinamento por Simulação/métodos , Realidade Virtual , Adulto , Educação Baseada em Competências/normas , Currículo , Dinamarca , Feminino , Procedimentos Cirúrgicos em Ginecologia/métodos , Procedimentos Cirúrgicos em Ginecologia/normas , Ginecologia/normas , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Procedimentos Cirúrgicos Robóticos/normas , Treinamento por Simulação/normas , Vagina/cirurgia
7.
Acta Obstet Gynecol Scand ; 96(3): 274-285, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28029176

RESUMO

INTRODUCTION: Robot-assisted surgery has become more widespread in gynecological oncology. The purpose of this systematic review is to present current knowledge on robot-assisted surgery, and to clarify and discuss controversies that have arisen alongside the development and deployment. MATERIAL AND METHODS: A database search in PubMed and EMBASE was performed up until 4 March 2016. The search strategy was developed in collaboration with an information specialist, and by application of the PRISMA guidelines. Human participants and English language were the only restrictive filters applied. Selection was performed by screening of titles and abstracts, and by full text scrutiny. From 2001 to 2016, a total of 76 references were included. RESULTS: Robot-assisted surgery in gynecological oncology has increased, and current knowledge supports that the oncological safety is similar, compared with previous surgical methods. Controversies arise because current knowledge does not clearly document the benefit of robot-assisted surgery, on perioperative outcome compared with the increased costs of the acquisition and application. CONCLUSIONS: The rapid development in robot-assisted surgery calls for long-term detailed prospective cohorts or randomized controlled trials. The costs associated with acquisition, application, and maintenance have an unfavorable impact on cost-benefit evaluations, especially when compared with laparoscopy. Future developments in robot-assisted surgery will hopefully lead to competition in the market, which will decrease costs.


Assuntos
Neoplasias dos Genitais Femininos/cirurgia , Procedimentos Cirúrgicos em Ginecologia/instrumentação , Análise Custo-Benefício , Feminino , Procedimentos Cirúrgicos em Ginecologia/economia , Humanos , Histerectomia/educação , Robótica/economia , Serviços de Saúde da Mulher/economia
8.
Acta Obstet Gynecol Scand ; 93(5): 483-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24617701

RESUMO

OBJECTIVE: To assess the reproductive long-term prognosis of women with and without endometriosis, to explore changes over time, and to quantify the contribution of artificial reproductive techniques. DESIGN: Cohort study. SETTING: Denmark 1977-2009. SAMPLE: Data retrieved from four national registries. Among 15-49-year-old women during the period 1977-82, 24 667 were diagnosed with endometriosis and 98 668 (1:4) women without endometriosis were age-matched. METHODS: To assess long-term reproductive prognosis, all pregnancy outcomes were identified among the women with and without endometriosis until the end of 2009. To explore changes over time, the endometriosis cohorts were followed for 15 years from the years 1980, 1986, 1992 and 1998, with the corresponding control cohorts. All pregnancy outcomes were categorized into naturally or artificially conceived pregnancies. MAIN OUTCOME MEASURES: Births, miscarriages, induced abortions, ectopic pregnancies and hydatidiform moles. RESULTS: Compared with women without endometriosis, women with endometriosis had a lowered relative risk for childbirth of 0.93 (95% confidence interval 0.92-0.95), for miscarriages the relative risk was 1.2 (95% confidence interval 1.2-1.3), ectopic pregnancies were almost twice as many (relative risk 1.9, 95% confidence interval 1.8-2.1), while frequencies of induced abortions were equivalent. The chances for childbirth increased over time from 0.82 to 0.92 (p < 0.001) with successive cohorts, but this was restricted to pregnancies from assisted reproduction. CONCLUSION: Women with endometriosis have slightly fewer children, but this lessened over time due to artificially conceived pregnancies. The risk for miscarriages and ectopic pregnancies was increased compared with women without the disease.


Assuntos
Aborto Induzido/estatística & dados numéricos , Aborto Espontâneo/epidemiologia , Endometriose/epidemiologia , Mola Hidatiforme/epidemiologia , Nascido Vivo/epidemiologia , Gravidez Ectópica/epidemiologia , Doenças Uterinas/epidemiologia , Adolescente , Adulto , Estudos de Casos e Controles , Dinamarca , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Prognóstico , Técnicas de Reprodução Assistida/estatística & dados numéricos , Fatores de Tempo , Adulto Jovem
9.
Surg Endosc ; 25(3): 722-7, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20927549

RESUMO

BACKGROUND: Virtual-reality (VR) simulator training has been shown to improve surgical performance in laparoscopic procedures in the operating room. We have, in a randomised controlled trial, demonstrated transferability to real operations. The validity of the LapSim virtual-reality simulator as an assessment tool has been demonstrated in several reports. However, an unanswered question regarding simulator training is the durability, or retention, of skills acquired during simulator training. The aim of the present study is to assess the retention of skills acquired using the LapSim VR simulator, 6 and 18 months after an initial training course. METHODS AND MATERIALS: The investigation was designed as a 6- and 18-month follow-up on a cohort of participants who earlier participated in a skills training programme on the LapSim VR. The follow-up cohort consisted of trainees and senior consultants allocated to two groups: (1) novices (experience < 5 procedures, n = 9) and (2) experts (experience > 200 procedures during the past 3 years, n = 10). Each participant performed ten sessions. Assessment of skills was based on time, economy of movement and the error parameter "bleeding". The novice group were re-tested after 6 and 18 months, whereas the expert group were only retested once, after 6 months. None of the novices performed laparoscopic surgery in the follow-up period. The experts continued their daily work with laparoscopic surgery. RESULTS AND CONCLUSIONS: Novices showed retention of skills after 6 months. After 18 months, novices' laparoscopic skills had returned to the pre-training level. This indicates that laparoscopic skills seemed to deteriorate in the period between 6 and 18 months without training. Experts showed consistent performance over time. This information can be included when planning training curricula in minimal invasive surgery.


Assuntos
Competência Clínica , Simulação por Computador , Instrução por Computador , Laparoscopia/educação , Retenção Psicológica , Adulto , Currículo , Educação Médica Continuada , Educação de Pós-Graduação em Medicina , Avaliação Educacional , Seguimentos , Procedimentos Cirúrgicos em Ginecologia/educação , Humanos , Laparoscopia/métodos , Pessoa de Meia-Idade , Prática Psicológica , Desempenho Psicomotor , Fatores de Tempo , Estudos de Tempo e Movimento , Interface Usuário-Computador
10.
BMJ ; 338: b1802, 2009 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-19443914

RESUMO

OBJECTIVE: To assess the effect of virtual reality training on an actual laparoscopic operation. DESIGN: Prospective randomised controlled and blinded trial. SETTING: Seven gynaecological departments in the Zeeland region of Denmark. PARTICIPANTS: 24 first and second year registrars specialising in gynaecology and obstetrics. INTERVENTIONS: Proficiency based virtual reality simulator training in laparoscopic salpingectomy and standard clinical education (controls). MAIN OUTCOME MEASURE: The main outcome measure was technical performance assessed by two independent observers blinded to trainee and training status using a previously validated general and task specific rating scale. The secondary outcome measure was operation time in minutes. RESULTS: The simulator trained group (n=11) reached a median total score of 33 points (interquartile range 32-36 points), equivalent to the experience gained after 20-50 laparoscopic procedures, whereas the control group (n=10) reached a median total score of 23 (22-27) points, equivalent to the experience gained from fewer than five procedures (P<0.001). The median total operation time in the simulator trained group was 12 minutes (interquartile range 10-14 minutes) and in the control group was 24 (20-29) minutes (P<0.001). The observers' inter-rater agreement was 0.79. CONCLUSION: Skills in laparoscopic surgery can be increased in a clinically relevant manner using proficiency based virtual reality simulator training. The performance level of novices was increased to that of intermediately experienced laparoscopists and operation time was halved. Simulator training should be considered before trainees carry out laparoscopic procedures. TRIAL REGISTRATION: ClinicalTrials.gov NCT00311792.


Assuntos
Competência Clínica/normas , Simulação por Computador , Educação de Pós-Graduação em Medicina , Cirurgia Geral/educação , Ginecologia/educação , Laparoscopia/normas , Adulto , Dinamarca , Feminino , Humanos , Masculino , Estudos Prospectivos , Ensino/métodos , Fatores de Tempo
11.
Maturitas ; 49(4): 304-14, 2004 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-15531126

RESUMO

OBJECTIVES: The aim of this study was in an animal model to assess the vascular effects of different progestins commonly used in hormonal replacement treatment. METHODS: Fifty-six non-atherosclerotic, ovariectomized New Zealand white rabbits were randomized into seven groups: (1) medroxyprogesterone acetate (MPA), (2) norethisterone acetate (NETA), (3) conjugated equine estrogens (CEE), (4) 17-beta-estradiol (E2), (5) MPA+CEE , (6) NETA+E2 , (7) or placebo (n=8) and given hormonal treatment through the diet for 4 weeks. Ring segments from the left proximal coronary artery and from the distal part of the left anterior descending coronary artery were microdissected and mounted for isometric tension recordings in a myograph. The vasoconstrictory responses induced by potassium, endothelin-1, calcium and Nw-nitro-L-arginine methyl ester, and the vasodilatory response induced by acetylcholine and sodiumnitroprusside were investigated. The maximum contraction/relaxation (Emax) and the concentration required to induce half the maximum response (EC50) were determined. EC50 values were expressed as the negative logarithm to the molar concentration, pD2=-log EC50. RESULTS: Treatment with MPA alone caused when compared to treatment with NETA an increase in tension development in the distal coronary artery after the addition of potassium ( 6.36+/-0.36 versus 4.31+/-0.42 P<0.005) (single dose response, mN/mm, mean+/-S.E.M.) and endothelin-1 (9.41+/-0.82 versus 6.43+/-0.73 P<0.05) (Emax, mN/mm, mean+/-S.E.M.). Treatment with MPA compared to placebo caused an endothelin-1 induced increase of Emax in the distal coronary artery (9.21+/-0.87 versus 6.51+/-0.65 P<0.05) and a calcium induced increase of pD2 in both coronary arteries (2.98+/-0.19 versus 2.42+/-0.12 P<0.05, proximal coronary artery) (3.26+/-0.09 versus 2.9+/-0.1 P<0.05, distal coronary artery) (pD2, mean+/-S.E.M.). Treatment with NETA compared to placebo in the proximal coronary artery, after the addition of sodiumnitroprusside caused a decrease of pD2 (5.33+/-0.19 versus 5.94+/-0.13 P<0.05). Treatment with E2 compared to treatment with CEE in the proximal coronary artery caused a decrease of pD2 after the addition of sodiumnitroprusside (5.00+/-0.16 versus 5.77+/-0.28 P<0.05). No significant differences were found between MPA+CEE and NETA+E2. CONCLUSION: Treatment with MPA alone seems to enhance the contractile response to potassium and endothelin-1 in the distal coronary artery compared to NETA, indicating that different progestins used in hormonal replacement treatment may display different effects on contractile functions of coronary arteries.


Assuntos
Vasos Coronários/efeitos dos fármacos , Terapia de Reposição de Estrogênios , Noretindrona/análogos & derivados , Progestinas/farmacologia , Acetilcolina , Animais , Artérias/efeitos dos fármacos , Cálcio , Modelos Animais de Doenças , Endotelina-1 , Estradiol/farmacologia , Estrogênios Conjugados (USP)/farmacologia , Feminino , Acetato de Medroxiprogesterona/farmacologia , Menopausa , NG-Nitroarginina Metil Éster , Nitroprussiato , Noretindrona/farmacologia , Acetato de Noretindrona , Ovariectomia , Potássio , Coelhos , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
12.
Maturitas ; 49(3): 179-88, 2004 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-15488346

RESUMO

OBJECTIVES: To compare the acute effects of estradiol, tibolone and its metabolites on coronary arteries in vitro and to investigate possible vascular mechanisms. METHODS: 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). RESULTS: 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). CONCLUSIONS: 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.


Assuntos
Vasos Coronários/efeitos dos fármacos , Moduladores de Receptor Estrogênico/farmacologia , Norpregnenos/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Área Sob a Curva , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Estradiol/farmacologia , Feminino , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , NG-Nitroarginina Metil Éster , Coelhos
13.
Regul Pept ; 116(1-3): 155-62, 2003 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-14599727

RESUMO

The aim of the present study was to evaluate the impact of long-term estrogen replacement therapy (ERT) on the vasodilatory effect of the two peptides vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) in atherosclerotic coronary and cerebral arteries. Female ovariectomized homozygous Watanabe heritable hyperlipidemic rabbits were randomized to 16 weeks treatment with 17beta-estradiol or placebo. The diet was semisynthetic, thereby avoiding the influence of phytoestrogens. Artery ring segments were mounted for isometric tension recordings in myographs. Following precontraction, the dose-response relationships for VIP and PACAP were evaluated.Treatment with 17beta-estradiol significantly improved the maximum VIP-mediated vasodilation (E(max), percentage of precontraction) in proximal coronary arteries (45.8+/-9.6% vs. 24.1+/-3.7%, p<0.05). In the same artery segment, 17beta-estradiol induced a significant decrease in the relative ratio between the repeated contractile response to potassium 30 and 120 mM (100+/-7% vs. 132+/-11%, p<0.05). For distal coronary arteries, there was a tendency to similar changes, but no statistical differences for the potassium or VIP responses in cerebral or distal coronary arteries were found between the two groups. 17beta-estradiol induced no changes in the PACAP-mediated vasodilation. These results suggest that long-term treatment with 17beta-estradiol improves the VIP-mediated but not the PACAP-mediated vasodilation in atherosclerotic proximal coronary arteries.


Assuntos
Arteriosclerose/patologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Estradiol/farmacologia , Peptídeo Intestinal Vasoativo/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Vasos Coronários/fisiologia , Relação Dose-Resposta a Droga , Feminino , Neuropeptídeos/farmacologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Coelhos , Radioimunoensaio , Fatores de Tempo
14.
Regul Pept ; 110(3): 179-88, 2003 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-12573798

RESUMO

Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) are closely related peptides with wide distribution in the nervous system. The aim of the present study was to investigate functional characteristics and the influence of sex steroids on the vasodilatory effects of these two peptides in cerebral and coronary vessels from female New Zealand White (NZW) rabbits. The localization and concentration of VIP and PACAP in cardiovascular tissue was evaluated using immunohistochemistry and radioimmunoassays. The vasodilatory effects of VIP and PACAP were investigated using myographs, allowing isometric tension recordings. In order to evaluate the influence of steroid hormones, the rabbits were ovariectomized and randomized to treatment for 4 weeks with 17beta-estradiol (E(2)), Norethindrone Acetate (NETA), E(2)+NETA or placebo. Ring segments of the posterior cerebral artery, the right proximal coronary artery and the distal left coronary artery were examined. The highest concentrations of VIP/PACAP were observed in cerebral and coronary arteries: 5.0/5.7 and 2.8/3.5 pmol/g, respectively. The peptides were localized in nerve fibres innervating the arteries. Both peptides produced dose-dependent vasodilatory responses in all vessels investigated. While the effects of PACAP were identical in cerebral and coronary arterial segments, the effects of VIP displayed significant differences (E(max), pI(2), Hill-slope). Treatment with sex steroids induced no changes in the vascular effects of the two peptides. These results indicate different mechanisms of action for the vasodilating effects of the two closely related peptides VIP and PACAP in different areas of the coronary and cerebrovascular tree. Treatment with female sex steroids does not seem to change these mechanisms.


Assuntos
Artérias Cerebrais/fisiologia , Vasos Coronários/fisiologia , Neuropeptídeos/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo , Vasodilatação , Animais , Artérias Cerebrais/efeitos dos fármacos , Vasos Coronários/efeitos dos fármacos , Feminino , Imuno-Histoquímica , Masculino , Neuropeptídeos/farmacologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Coelhos , Peptídeo Intestinal Vasoativo/farmacologia , Vasodilatação/efeitos dos fármacos
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