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1.
BMJ Open ; 14(5): e070857, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38821570

RESUMO

INTRODUCTION: The diagnosis of neovascular age-related macular degeneration (nAMD), the leading cause of visual impairment in the developed world, relies on the interpretation of various imaging tests of the retina. These include invasive angiographic methods, such as Fundus Fluorescein Angiography (FFA) and, on occasion, Indocyanine-Green Angiography (ICGA). Newer, non-invasive imaging modalities, predominately Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA), have drastically transformed the diagnostic approach to nAMD. The aim of this study is to undertake a comprehensive diagnostic accuracy assessment of the various imaging modalities used in clinical practice for the diagnosis of nAMD (OCT, OCTA, FFA and, when a variant of nAMD called Polypoidal Choroidal Vasculopathy is suspected, ICGA) both alone and in various combinations. METHODS AND ANALYSIS: This is a non-inferiority, prospective, randomised diagnostic accuracy study of 1067 participants. Participants are patients with clinical features consistent with nAMD who present to a National Health Service secondary care ophthalmology unit in the UK. Patients will undergo OCT as per standard practice and those with suspicious features of nAMD on OCT will be approached for participation in the study. Patients who agree to take part will also undergo both OCTA and FFA (and ICGA if indicated). Interpretation of the imaging tests will be undertaken by clinicians at recruitment sites. A randomised design was selected to avoid bias from consecutive review of all imaging tests by the same clinician. The primary outcome of the study will be the difference in sensitivity and specificity between OCT+OCTA and OCT+FFA (±ICGA) for nAMD detection as interpreted by clinicians at recruitment sites. ETHICS AND DISSEMINATION: The study has been approved by the South Central-Oxford B Research Ethics Committee with reference number 21/SC/0412.Dissemination of study results will involve peer-review publications, presentations at major national and international scientific conferences. TRIAL REGISTRATION NUMBER: ISRCTN18313457.


Assuntos
Angiofluoresceinografia , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Angiofluoresceinografia/métodos , Reino Unido , Estudos Prospectivos , Degeneração Macular/diagnóstico por imagem , Neovascularização de Coroide/diagnóstico por imagem , Neovascularização de Coroide/diagnóstico , Estudos Multicêntricos como Assunto , Degeneração Macular Exsudativa/diagnóstico por imagem , Degeneração Macular Exsudativa/diagnóstico , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
BMJ Open ; 13(9): e070218, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37669836

RESUMO

INTRODUCTION: There is uncertainty about the advantages and disadvantages of laparoscopic hysterectomy compared with abdominal hysterectomy, particularly the relative rate of complications of the two procedures. While uptake of laparoscopic hysterectomy has been slow, the situation is changing with greater familiarity, better training, better equipment and increased proficiency in the technique. Thus, a large, robust, multicentre randomised controlled trial (RCT) is needed to compare contemporary laparoscopic hysterectomy with abdominal hysterectomy to determine the safest and most cost-effective technique. METHODS AND ANALYSIS: A parallel, open, non-inferiority, multicentre, randomised controlled, expertise-based surgery trial with integrated health economic evaluation and an internal pilot with an embedded qualitative process evaluation. A within trial-based economic evaluation will explore the cost-effectiveness of laparoscopic hysterectomy compared with open abdominal hysterectomy. We will aim to recruit 3250 women requiring a hysterectomy for a benign gynaecological condition and who were suitable for either laparoscopic or open techniques. The primary outcome is major complications up to six completed weeks postsurgery and the key secondary outcome is time from surgery to resumption of usual activities using the personalised Patient-Reported Outcomes Measurement Information System Physical Function questionnaire. The principal outcome for the economic evaluation is to be cost per QALY at 12 months' postsurgery. A secondary analysis is to be undertaken to generate costs per major surgical complication avoided and costs per return to normal activities. ETHICS AND DISSEMINATION: The study was approved by the West Midlands-Edgbaston Research Ethics Committee, 18 February 2021 (Ethics ref: 21/WM/0019). REC approval for the protocol version 2.0 dated 2 February 2021 was issued on 18 February 2021.We will present the findings in national and international conferences. We will also aim to publish the findings in high impact peer-reviewed journals. We will disseminate the completed paper to the Department of Health, the Scientific Advisory Committees of the RCOG, the Royal College of Nurses (RCN) and the BSGE. TRIAL REGISTRATION NUMBER: ISRCTN14566195.


Assuntos
Laparoscopia , Feminino , Humanos , Histerectomia , Comitês Consultivos , Análise Custo-Benefício , Comitês de Ética em Pesquisa , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
3.
Health Technol Assess ; 26(22): 1-74, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35435818

RESUMO

BACKGROUND: Uterine fibroids are the most common tumour in women of reproductive age and are associated with heavy menstrual bleeding, abdominal discomfort, subfertility and reduced quality of life. For women wishing to retain their uterus and who do not respond to medical treatment, myomectomy and uterine artery embolisation are therapeutic options. OBJECTIVES: We examined the clinical effectiveness and cost-effectiveness of uterine artery embolisation compared with myomectomy in the treatment of symptomatic fibroids. DESIGN: A multicentre, open, randomised trial with a parallel economic evaluation. SETTING: Twenty-nine UK hospitals. PARTICIPANTS: Premenopausal women who had symptomatic uterine fibroids amenable to myomectomy or uterine artery embolisation were recruited. Women were excluded if they had significant adenomyosis, any malignancy or pelvic inflammatory disease or if they had already had a previous open myomectomy or uterine artery embolisation. INTERVENTIONS: Participants were randomised to myomectomy or embolisation in a 1 : 1 ratio using a minimisation algorithm. Myomectomy could be open abdominal, laparoscopic or hysteroscopic. Embolisation of the uterine arteries was performed under fluoroscopic guidance. MAIN OUTCOME MEASURES: The primary outcome was the Uterine Fibroid Symptom Quality of Life questionnaire (with scores ranging from 0 to 100 and a higher score indicating better quality of life) at 2 years, adjusted for baseline score. The economic evaluation estimated quality-adjusted life-years (derived from EuroQol-5 Dimensions, three-level version, and costs from the NHS perspective). RESULTS: A total of 254 women were randomised - 127 to myomectomy (105 underwent myomectomy) and 127 to uterine artery embolisation (98 underwent embolisation). Information on the primary outcome at 2 years was available for 81% (n = 206) of women. Primary outcome scores at 2 years were 84.6 (standard deviation 21.5) in the myomectomy group and 80.0 (standard deviation 22.0) in the uterine artery embolisation group (intention-to-treat complete-case analysis mean adjusted difference 8.0, 95% confidence interval 1.8 to 14.1, p = 0.01; mean adjusted difference using multiple imputation for missing responses 6.5, 95% confidence interval 1.1 to 11.9). The mean difference in the primary outcome at the 4-year follow-up time point was 5.0 (95% CI -1.4 to 11.5; p = 0.13) in favour of myomectomy. Perioperative and postoperative complications from all initial procedures occurred in similar percentages of women in both groups (29% in the myomectomy group vs. 24% in the UAE group). Twelve women in the uterine embolisation group and six women in the myomectomy group reported pregnancies over 4 years, resulting in seven and five live births, respectively (hazard ratio 0.48, 95% confidence interval 0.18 to 1.28). Over a 2-year time horizon, uterine artery embolisation was associated with higher costs than myomectomy (mean cost £7958, 95% confidence interval £6304 to £9612, vs. mean cost £7314, 95% confidence interval £5854 to £8773), but with fewer quality-adjusted life-years gained (0.74, 95% confidence interval 0.70 to 0.78, vs. 0.83, 95% confidence interval 0.79 to 0.87). The differences in costs (difference £645, 95% confidence interval -£1381 to £2580) and quality-adjusted life-years (difference -0.09, 95% confidence interval -0.11 to -0.04) were small. Similar results were observed over the 4-year time horizon. At a threshold of willingness to pay for a gain of 1 QALY of £20,000, the probability of myomectomy being cost-effective is 98% at 2 years and 96% at 4 years. LIMITATIONS: There were a substantial number of women who were not recruited because of their preference for a particular treatment option. CONCLUSIONS: Among women with symptomatic uterine fibroids, myomectomy resulted in greater improvement in quality of life than did uterine artery embolisation. The differences in costs and quality-adjusted life-years are very small. Future research should involve women who are desiring pregnancy. TRIAL REGISTRATION: This trial is registered as ISRCTN70772394. FUNDING: This study was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme, and will be published in full in Health Technology Assessment; Vol. 26, No. 22. See the NIHR Journals Library website for further project information.


WHAT IS THE PROBLEM?: Uterine fibroids are the most common non-cancerous tumour in women of childbearing age. Uterine fibroids are associated with heavy bleeding, lower chances of having children and reduced quality of life. Traditional surgical options were either to remove the fibroids (via myomectomy) or to completely remove the womb. A newer approach, known as uterine artery embolisation, involves blocking the blood supply to the fibroids in the womb. WHAT DID WE PLAN TO DO?: We compared myomectomy with uterine artery embolisation in women with fibroids who wanted to keep their womb. We wanted to see which treatment improved quality of life, was associated with the fewest complications and was the best value for money for the NHS. We also wanted to see if either treatment had an impact on women's ability to get pregnant and give birth. We included 254 women in a clinical trial. Women were assigned to have myomectomy or uterine artery embolisation at random to ensure a fair comparison. Women completed questionnaires about their symptoms and quality of life at intervals up to 4 years after treatment. WHAT DID WE FIND?: We found that myomectomy improved women's quality of life more than uterine artery embolisation. Complications from the treatments occurred in a similar proportion of women. There appeared to be no difference on reproductive hormone levels between treatments. Too few women in the trial got pregnant for any difference in the numbers of women having children to be seen. The differences in costs and overall disease burden were small. WHAT DOES THIS MEAN?: Both treatments improve quality of life and cost about the same to the NHS but, on average, myomectomy will provide greater benefit to women. There is no evidence to suggest that either treatment is unsuitable for women wanting to get pregnant, but more research is needed in younger women.


Assuntos
Leiomioma , Embolização da Artéria Uterina , Miomectomia Uterina , Feminino , Humanos , Histerectomia , Leiomioma/cirurgia , Masculino , Gravidez , Qualidade de Vida
4.
Eur J Obstet Gynecol Reprod Biol X ; 13: 100139, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34877531

RESUMO

OBJECTIVE: To examine the quality of life experienced by women with symptomatic uterine fibroids who had been treated with UAE in comparison to myomectomy. We report the four-year follow-up of the FEMME randomised trial. Two-year follow-up data has been previously reported. STUDY DESIGN: Premenopausal women who had symptomatic uterine fibroids amenable to myomectomy or uterine artery embolization were recruited from 29 UK hospitals. Women were excluded if they had significant adenomyosis, any malignancy, pelvic inflammatory disease or had had a previous open myomectomy or uterine artery embolization.Participants were randomised to myomectomy or embolization in a 1:1 ratio using a minimisation algorithm. Myomectomy could be open abdominal, laparoscopic or hysteroscopic, according to clinician preference. Embolization of the uterine arteries was performed according to local practice, under fluoroscopic guidance.The primary outcome measure was the Uterine Fibroid Symptom Quality of Life questionnaire, adjusted for baseline score and reported here at four years post-randomisation. Subsequent procedures for fibroids, pregnancy and outcome were amongst secondary outcomes.Trial registration ISRCTN70772394 https://doi.org/10.1186/ISRCTN70772394. RESULTS: 254 women were randomized, 127 to myomectomy (105 underwent myomectomy) and 127 to uterine artery embolization (98 underwent embolization). At four years, 67 (53%) and 81 (64%) completed UFS-QoL quality of life scores. Mean difference in the UFS-QoL at 4 years was 5.0 points (95% CI -1.4 to 11.5; p = 0.13) in favour of myomectomy. There were 15 pregnancies in the UAE group and 7 in the myomectomy group, with a cumulative pregnancy rate to four years of 15% and 6% respectively (hazard ratio: 0.48; 95% CI 0.18-1.28). The cumulative repeat procedure rate to four years was 24% in the UAE group and 13% in the myomectomy group (hazard ratio: 0.53; 95% CI 0.27-1.05). CONCLUSIONS: Myomectomy resulted in greater improvement in quality of life compared with uterine artery embolization, although by four years, this difference was not statistically significant. Missing data may limit the generalisability of this result. The numbers of women becoming pregnant were too small draw a conclusion on the effect of the procedures on fertility.

5.
N Engl J Med ; 383(5): 440-451, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32726530

RESUMO

BACKGROUND: Uterine fibroids, the most common type of tumor among women of reproductive age, are associated with heavy menstrual bleeding, abdominal discomfort, subfertility, and a reduced quality of life. For women who wish to preserve their uterus and who have not had a response to medical treatment, myomectomy and uterine-artery embolization are therapeutic options. METHODS: We conducted a multicenter, randomized, open-label trial to evaluate myomectomy, as compared with uterine-artery embolization, in women who had symptomatic uterine fibroids and did not want to undergo hysterectomy. Procedural options included open abdominal, laparoscopic, or hysteroscopic myomectomy. The primary outcome was fibroid-related quality of life, as assessed by the score on the health-related quality-of-life domain of the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire (scores range from 0 to 100, with higher scores indicating a better quality of life) at 2 years; adjustment was made for the baseline score. RESULTS: A total of 254 women, recruited at 29 hospitals in the United Kingdom, were randomly assigned: 127 to the myomectomy group (of whom 105 underwent myomectomy) and 127 to the uterine-artery embolization group (of whom 98 underwent embolization). Data on the primary outcome were available for 206 women (81%). In the intention-to-treat analysis, the mean (±SD) score on the health-related quality-of-life domain of the UFS-QOL questionnaire at 2 years was 84.6±21.5 in the myomectomy group and 80.0±22.0 in the uterine-artery embolization group (mean adjusted difference with complete case analysis, 8.0 points; 95% confidence interval [CI], 1.8 to 14.1; P = 0.01; mean adjusted difference with missing responses imputed, 6.5 points; 95% CI, 1.1 to 11.9). Perioperative and postoperative complications from all initial procedures, irrespective of adherence to the assigned procedure, occurred in 29% of the women in the myomectomy group and in 24% of the women in the uterine-artery embolization group. CONCLUSIONS: Among women with symptomatic uterine fibroids, those who underwent myomectomy had a better fibroid-related quality of life at 2 years than those who underwent uterine-artery embolization. (Funded by the National Institute for Health Research Health Technology Assessment program; FEMME Current Controlled Trials number, ISRCTN70772394.).


Assuntos
Leiomioma/cirurgia , Qualidade de Vida , Embolização da Artéria Uterina , Miomectomia Uterina , Neoplasias Uterinas/cirurgia , Adulto , Feminino , Humanos , Histeroscopia , Análise de Intenção de Tratamento , Complicações Intraoperatórias , Laparoscopia , Leiomioma/terapia , Tempo de Internação , Menorragia , Pessoa de Meia-Idade , Reserva Ovariana , Complicações Pós-Operatórias , Reoperação/estatística & dados numéricos , Embolização da Artéria Uterina/efeitos adversos , Miomectomia Uterina/efeitos adversos , Miomectomia Uterina/métodos , Neoplasias Uterinas/terapia , Útero/cirurgia
6.
Arthroscopy ; 29(6): 972-81, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23571131

RESUMO

PURPOSE: To assess molecular and histologic differences between the proximal (intra-articular) and distal (extra-articular) portions of the long head of the biceps (LHB) tendon in 3 different disease states (biceps instability, tendinosis, and degenerative joint disease [DJD]) compared with a healthy tendon (fresh frozen). METHODS: We used 32 LHB tendons of patients undergoing tenodesis (mean age, 54.7 ± 10.1 years) and 9 harvested tissue donors. Tendons were divided according to 4 diagnostic groups: (1) biceps instability, (2) tendinosis, (3) DJD, and (4) normal control. After sectioning, tendons were fixed in formalin and stained with H&E and alcian blue for histologic analysis. Measurements of collagen organization by use of polarized light microscopy was then performed, and protein expression for type I and type III collagen, tenascin C, and decorin was determined. RESULTS: There were no statistical differences found for protein expression of type I or type III collagen, tenascin C, or decorin. The proximal and distal regions of the tendons had statistically significant differences in alcian blue staining, with the proximal portion containing a higher amount of proteoglycan (instability, P = .001; tendinosis, P = .005; DJD, P = .008; control, P = .011). When compared with the nonpathologic control tendons, a significant increase in alcian blue staining for the proximal region was seen in all 3 groups. Total polarized light analysis showed that the distal tendon had a significantly higher intensity (organization) compared with the proximal tendon (P < .001); this was also seen in all of the diagnostic groups (instability, P = .010; tendinosis, P = .013; DJD, P = .07; control, P = .028). CONCLUSIONS: This study showed a greater degree of degeneration of the proximal (intra-articular) regions of the LHB tendon when compared with the distal regions in all pathologic groups. However, no major differences at the cellular level were found among groups. CLINICAL RELEVANCE: The pathomechanisms of the various forms of known LHB diagnoses are not yet fully understood and basic science studies may help in understanding their etiology and therefore optimizing treatment options.


Assuntos
Artropatias/patologia , Músculo Esquelético/patologia , Articulação do Ombro/patologia , Tendinopatia/patologia , Tendões/patologia , Adulto , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Decorina/metabolismo , Feminino , Humanos , Artropatias/metabolismo , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Músculo Esquelético/cirurgia , Osteoartrite/metabolismo , Osteoartrite/patologia , Articulação do Ombro/anatomia & histologia , Tenascina/metabolismo , Tendinopatia/metabolismo , Tendões/anatomia & histologia , Tendões/metabolismo , Adulto Jovem
7.
Knee Surg Sports Traumatol Arthrosc ; 20(9): 1666-72, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22005966

RESUMO

PURPOSE: Results of in vitro cell models are commonly used to promote new therapies (e.g., platelet-rich plasma), and clinicians have to be aware of the specific limitations of such models. To gain a sufficient and effective cell load, many current in vitro models use cells multiplied through various passages. This is especially important in tendon-like cell (TLC) models, since native tendon tissue is not available unlimited and contains limited amount of tenocytes. The purpose was to determine the occurrence of phenotypic changes following extended monolayer culture of TLCs, according to cell-passage number. METHODS: Tendon samples were obtained from 15 healthy patients undergoing biceps tenodesis. Tendons were digested and cultured (monolayer) for six passages. Tendon-specific markers (collagens I and III, decorin, tenascin-C, and tenomodulin) and their histology were analyzed using gene expression and protein content assays. Native cells, the cells cultured and cells passaged one to six times were analyzed at each passage. RESULTS: Gene expression of types I and III collagen of cultured TLCs significantly decreased after two passages. Gene expression of decorin, tenascin-C, and tenomodulin exhibited a trend of decreased gene expression with increased passage. Protein levels of types I and III collagen and decorin decreased after four passages. CONCLUSIONS: The significant findings let conclude that tenocyte-like cells obtained from human LHB can be maintained in monolayer culture at low passages, before the signs of phenotypic drift are present. But researchers must be aware of rapid phenotypic drift at higher passage numbers. Therefore, only cells within the first 3 passages should be used as a precaution for in vitro monolayer cell models, and one has to be aware of the phenotypic changes if TLCs passaged multiple times are used. The clinical relevance of this data is that understanding of in vitro TLC models, and their limitations may finally help the clinician to judge the potential of experimental data of new biologic treatment options.


Assuntos
Tendões/citologia , Tendões/metabolismo , Biomarcadores/metabolismo , Células Cultivadas , Colágeno Tipo I/biossíntese , Colágeno Tipo I/genética , Colágeno Tipo III/biossíntese , Colágeno Tipo III/genética , Decorina/biossíntese , Decorina/genética , Expressão Gênica , Humanos , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Músculo Esquelético , Tenascina/biossíntese , Tenascina/genética , Tendões/cirurgia , Tenodese
8.
Steroids ; 75(13-14): 1137-45, 2010 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-20688094

RESUMO

Partial inhibition of the sodium pump (Na/K-ATP-ase) by a circulating inhibitor is known to occur in humans. The objectives of this study were to determine the effects of novel bufadienolides lacking an oxygen at C14 on sodium pumps in human erythrocytes and leucocytes, dog kidney and pig brain and to document the importance of the stereochemistry at C17 on the ability to inhibit these sodium pumps. 14α bufadienolides were weak inhibitors of all preparations studied. 3ß-OH,5ß,14ß bufadienolide produced near-total inhibition of dog kidney and pig brain Na/K-ATP-ase. Over the same concentration range, it maximally inhibited the sodium pump of erythrocytes by 70% and leucocytes by 47%. The inhibition profile induced in the leucocyte sodium pump deviated significantly from the simple sigmoidal relationship present in the other preparations over the 3×10(-5) to 1×10(-7) mol/l concentration range. Allo-emicymarin (17α) was confirmed to be a weak inhibitor of the sodium pump/ATP-ase compared with emicymarin (17ß) but both were weaker inhibitors of the leucocyte sodium pump than that of the other preparations. Molecules with the C14 in the ß configuration are more efficacious than in the α configuration. In the case of emicymarin, the attachment of the furone at C17 in the α configuration results in substantially weaker inhibitory activity than in the beta configuration, seen in most cardenolides and bufadienolides. Unlike ouabain and bufalin that show no specificity of action in these preparations, 3ß- OH,5ß,14ß bufadienolide selectively inhibits the activity of at least one low-prevalence subset of the leucocyte Na/K-ATP-ase.


Assuntos
Bufanolídeos/química , Bufanolídeos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Saponinas/farmacologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Animais , Cães , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Humanos , Ouabaína/metabolismo , Ouabaína/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Estereoisomerismo
9.
Arthroscopy ; 26(6): 821-31, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20511042

RESUMO

Surgical interference screws and suture anchors for attaching soft tissue, such as ligaments and tendons, to bone are routinely used in arthroscopic surgery and sports medicine. Interference screw fixation provides a press fit between bone, graft/tendon, and screw and is frequently used to attach replacement ligaments in tunnels drilled for anterior and posterior cruciate ligament reconstruction. Suture anchors are used in surgical procedures wherein it is necessary for a surgeon to attach (tie) tissue to the surface of the bone, for example, during joint reconstruction and ligament repair or replacement. The composition of these implants ranges from metals to polymers and composites. Typically, because of the relatively large amount of torque that must be applied during insertion, these screws are constructed from metal. However, interference screws and suture anchors have also been constructed from bioabsorbable polymers and composites. The ideal material would (1) provide adequate mechanical fixation, (2) completely degrade once no longer needed, and (3) be completely replaced by bone. Because no material has been shown to be superior for all applications, the surgeon must weigh the advantages and disadvantages of each to evaluate the optimum material for a given application and patient. The purpose of this article is to present a comprehensive review of the commercially available interference screws and suture anchors, with an emphasis on implant composition, interaction, and design. This article provides the orthopaedic surgeon with a background on biomaterials, specifically those used in interference screws and suture anchors. Because there is no material that is perfect for all surgical situations, this review can be used to make educated decisions on a case-by-case basis.


Assuntos
Materiais Biocompatíveis , Parafusos Ósseos , Lesões dos Tecidos Moles/cirurgia , Âncoras de Sutura , Implantes Absorvíveis , Cerâmica , Desenho de Equipamento , Humanos , Teste de Materiais , Metais , Procedimentos Ortopédicos/instrumentação , Procedimentos Ortopédicos/métodos , Polímeros
10.
J Hypertens ; 27(1): 3-8, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19050442

RESUMO

Substantial evidence points to the presence in human plasma of an inhibitor of the sodium/potassium pump which plays a central role in the pathophysiology of circulatory disorders, including essential hypertension. Studies from the 1980/90s claimed that this inhibitor was identical or very similar in structure to plant-derived ouabain and was synthesized by the adrenal cortex. However, the physical evidence in studies reporting isolation and identification of ouabain in human plasma appears insecure on closer examination. Additionally, reported circulating levels of immunoreactive ouabain in humans vary greatly, the ability of the human adrenal glands to secrete ouabain is questionable and the original commercial assay for measuring immunoreactive ouabain is no longer available. We submit that the position of ouabain as an endogenous, adrenally produced regulator of the sodium pump is of such importance that the current evidence needs either to put on a more secure footing or to lose its current status.


Assuntos
Glândulas Suprarrenais/metabolismo , Cardenolídeos/sangue , Doenças Cardiovasculares/etiologia , Ouabaína/sangue , Saponinas/sangue , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Animais , Cardenolídeos/administração & dosagem , Cardenolídeos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Dieta , Humanos , Ouabaína/isolamento & purificação , Saponinas/administração & dosagem , Saponinas/isolamento & purificação
11.
J Hypertens ; 21(12): 2315-21, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14654752

RESUMO

BACKGROUND: We have previously reported the isolation from human placentas of an inhibitor of the sodium pump (Na/K ATP-ase) of molecular weight 370 Da, which is considered to have a dihydropyrone-substituted steroid (bufenolide) structure. OBJECTIVE: To examine if this inhibitor is present outside of the pregnant state. METHODS: We examined the plasma ultrafiltrate of patients who were clinically volume-expanded. During the period of this study five such patients were identified. One was receiving haemofiltration for acute renal failure and four were being treated by plasma exchange. High performance liquid chromatograph (HPLC) purified fractions obtained from each of these five patients inhibited the human leucocyte sodium pump in vitro. RESULTS: Each of the purified fractions that inhibited the leucocyte ATP-ase in vitro contained a compound of mass 370 Da, the same mass as that found previously in placental extracts. This inhibitory factor was absent from HPLC purified fractions of plasma ultrafiltrate obtained from fifty-five patients who were clinically normovolaemic. Negative ion mass spectrometry (MS)/MS of the inhibitory material produced the fragmentation pattern characteristic of the placenta-derived pump inhibitor in only one of the five samples. The other four samples, although having the same mass, exhibited a different fragmentation pattern. CONCLUSION: The results suggest that an inhibitor of the sodium pump, identical in mass to that obtained from human placentas, circulates in the plasma of volume-expanded patients. The fragmentation pattern observed in negative ion mass spectrometry in the majority of the volume expanded patients may represent the presence of an isomer of the sodium pump inhibitor previously described in placental material.


Assuntos
Volume Plasmático/fisiologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/sangue , Idoso , Biomarcadores/sangue , Pressão Sanguínea/fisiologia , Líquido Extracelular/citologia , Líquido Extracelular/efeitos dos fármacos , Líquido Extracelular/metabolismo , Feminino , Hemofiltração , Humanos , Hipertensão/sangue , Hipertensão/fisiopatologia , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Peso Molecular
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