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2.
Trials ; 24(1): 584, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37700365

RESUMEN

BACKGROUND: Approximately one in ten women have high blood pressure during pregnancy. Hypertension is associated with adverse maternal and perinatal outcomes, and as treatment improves maternal outcomes, antihypertensive treatment is recommended. Previous trials have been unable to provide a definitive answer on which antihypertensive treatment is associated with optimal maternal and neonatal outcomes and the need for robust evidence evaluating maternal and infant benefits and risks remains an important, unanswered question for research and clinical communities. METHODS: The Giant PANDA study is a pragmatic, open-label, multicentre, randomised controlled trial of a treatment initiation strategy with nifedipine (calcium channel blocker), versus labetalol (mixed alpha/beta blocker) in 2300 women with pregnancy hypertension. The primary objective is to evaluate if treatment with nifedipine compared to labetalol in women with pregnancy hypertension reduces severe maternal hypertension without increasing fetal or neonatal death or neonatal unit admission. Subgroup analyses will be undertaken by hypertension type (chronic, gestational, pre-eclampsia), diabetes (yes, no), singleton (yes, no), self-reported ethnicity (Black, all other), and gestational age at randomisation categories (11 + 0 to 19 + 6, 20 + 0 to 27 + 6, 28 + 0 to 34 + 6 weeks). A cost-effectiveness analysis using an NHS perspective will be undertaken using a cost-consequence analysis up to postnatal hospital discharge and an extrapolation exercise with a lifetime horizon conditional on the results of the cost-consequence analysis. DISCUSSION: This trial aims to address the uncertainty of which antihypertensive treatment is associated with optimal maternal and neonatal outcomes. The trial results are intended to provide definitive evidence to inform guidelines and linked, shared decision-making tools, thus influencing clinical practice. TRIAL REGISTRATION: EudraCT number: 2020-003410-12, ISRCTN: 12,792,616 registered on 18 November 2020.


Asunto(s)
Hipertensión , Labetalol , Preeclampsia , Ursidae , Embarazo , Lactante , Recién Nacido , Animales , Femenino , Humanos , Labetalol/efectos adversos , Nifedipino/efectos adversos , Antihipertensivos/efectos adversos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Multicéntricos como Asunto
3.
Eur Geriatr Med ; 13(6): 1343-1355, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36385690

RESUMEN

PURPOSE: Infections cause considerable care home morbidity and mortality. Nitric oxide (NO) has broad-spectrum anti-viral, bacterial and yeast activity in vitro. We assessed the feasibility of supplementing dietary nitrate (NO substrate) intake in care home residents. METHODS: We performed a cluster-randomised placebo-controlled trial in UK residential and nursing care home residents and compared nitrate containing (400 mg) versus free (0 mg daily) beetroot juice given for 60 days. Outcomes comprised feasibility of recruitment, adherence, salivary and urinary nitrate, and ordinal infection/clinical events. RESULTS: Of 30 targeted care homes in late 2020, 16 expressed interest and only 6 participated. 49 residents were recruited (median 8 [interquartile range 7-12] per home), mean (standard deviation) age 82 (8) years, with proxy consent 41 (84%), advance directive for hospital non-admission 8 (16%) and ≥ 1 doses of COVID-19 vaccine 37 (82%). Background dietary nitrate was < 30% of acceptable daily intake. 34 (76%) residents received > 50% of juice. Residents randomised to nitrate vs placebo had higher urinary nitrate levels, median 50 [18-175] v 18 [10-50] mg/L, difference 25 [0-90]. Data paucity precluded clinical between-group comparisons; the outcome distribution was as follows: no infection 32 (67%), uncomplicated infection 0, infection requiring healthcare support 11 (23%), all-cause hospitalisation 5 (10%), all-cause mortality 0. Urinary tract infections were most common. CONCLUSIONS: Recruiting UK care homes during the COVID-19 pandemic was partially successful. Supplemented dietary nitrate was tolerated and elevated urinary nitrate. Together, infections, hospitalisations and deaths occurred in 33% of residents over 60 days. A larger trial is now required. TRIAL REGISTRATION: ISRCTN51124684. Application date 7/12/2020; assignment date 13/1/2021.


Asunto(s)
Beta vulgaris , COVID-19 , Humanos , Anciano de 80 o más Años , COVID-19/epidemiología , Nitratos/uso terapéutico , Pandemias , Estudios de Factibilidad , Vacunas contra la COVID-19 , Suplementos Dietéticos , Óxidos de Nitrógeno
4.
Br J Clin Pharmacol ; 87(12): 4726-4736, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-33982797

RESUMEN

AIMS: To test if 6 months' intervention with dietary nitrate and spironolactone could affect carotid subclinical atherosclerosis and stiffness, respectively, vs. placebo/doxazosin, to control for blood pressure (BP). METHODS: A subgroup of participants in our double-blind, randomized-controlled, factorial VaSera trial had carotid imaging. Patients with hypertension and with/at risk of type 2 diabetes were randomized to active nitrate-containing beetroot juice or placebo nitrate-depleted juice, and spironolactone or doxazosin. Vascular ultrasound for carotid diameter (CD, mm) and intima-media thickness (CIMT, mm) was performed at baseline, 3- and 6-months. Carotid local stiffness (CS, m/s) was estimated from aortic pulse pressure (Arteriograph) and carotid lumen area. Data were analysed by modified intention to treat and using mixed-model effect, adjusted for confounders. RESULTS: In total, 93 subjects had a baseline evaluation and 86% had follow-up data. No statistical interactions occurred between the juice and drug arms and BP was similar between the juices and between the drugs. Nitrate-containing vs. placebo juice significantly lowered CIMT (-0.06 [95% confidence interval -0.12, -0.01], P = .034), an overall difference of ~8% relative to baseline; but had no effect on CD or CS. Doxazosin appeared to reduce CS from baseline (-0.34 [-0.62, -0.06]) however, no difference was detected vs. spironolactone (-0.15 [-0.46, 0.16]). No differences were detected between spironolactone or doxazosin on CIMT and CD. CONCLUSIONS: Our results show that 6 months' intervention with dietary nitrate influences vascular remodelling, but not carotid stiffness or diameter. Neither spironolactone nor doxazosin had a BP-independent effect on carotid structure and function.


Asunto(s)
Aterosclerosis , Beta vulgaris , Diabetes Mellitus Tipo 2 , Aterosclerosis/tratamiento farmacológico , Beta vulgaris/química , Presión Sanguínea , Grosor Intima-Media Carotídeo , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Método Doble Ciego , Humanos , Nitratos
5.
Br J Clin Pharmacol ; 87(2): 577-587, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32520418

RESUMEN

AIMS: Dietary nitrate from sources such as beetroot juice lowers blood pressure (BP) via the nitrate-nitrite-nitric oxide (NO) pathway. However, NO and nitrite are inactivated via reoxidation to nitrate, potentially limiting their activity. Cytochrome P450-3A4 inhibition with troleandomycin prevents nitrite re-oxidation to nitrate in rodent liver. Grapefruit juice contains the CYP3A4 inhibitor furanocoumarin. We therefore hypothesized that grapefruit juice would enhance BP-lowering with beetroot juice by maintaining circulating [nitrite]. METHODS: We performed a randomized, placebo-controlled, 7-hour crossover study in 11 healthy volunteers, attending on 3 occasions, receiving: a 70-mL shot of active beetroot juice (Beet-It) and either (i) 250 mL grapefruit juice (Active Beet+GFJ), or (ii) 250 mL water (Buxton, Active Beet+H2 O); or (iii) Placebo Beet+GFJ. RESULTS: The addition of grapefruit juice to active beetroot juice lowered systolic BP (SBP): Active Beet+GFJ vs Active Beet+H2 O (P = .02), and pulse pressure, PP (P = .0003). Peak mean differences in SBP and PP were seen at T = 5 hours: -3.3 mmHg (95% confidence interval [CI] -6.43 to -0.15) and at T = 2.5 hours: -4.2 mmHg (95% CI -0.3 to -8.2), respectively. Contrary to the hypothesis, plasma [nitrite] was lower with Active Beet+GFJ vs Active Beet+H2 O (P = .006), as was salivary nitrite production (P = .002) and saliva volume (-0.34 mL/min [95% CI -0.05 to -0.68]). The taste score of Beet+GFJ was 1.4/10 points higher than Beet+H2 O (P = .03). CONCLUSION: Grapefruit juice enhanced beetroot juice's effect on lowering SBP and PP despite decreasing plasma [nitrite]. Besides suggesting more complex mechanisms, there is potential for maximising the clinical benefit of dietary nitrate and targeting isolated systolic hypertension.


Asunto(s)
Beta vulgaris , Citrus paradisi , Presión Sanguínea , Estudios Cruzados , Suplementos Dietéticos , Jugos de Frutas y Vegetales , Nitratos
6.
NMR Biomed ; 33(11): e4385, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32754921

RESUMEN

Quantitative MRI and MRS of muscle are increasingly being used to measure individual pathophysiological processes in Becker muscular dystrophy (BMD). In particular, muscle fat fraction was shown to be highly associated with functional tests in BMD. However, the muscle strength per unit of contractile cross-sectional area is lower in patients with BMD compared with healthy controls. This suggests that the quality of the non-fat-replaced (NFR) muscle tissue is lower than in healthy controls. Consequently, a measure that reflects changes in muscle tissue itself is needed. Here, we explore the potential of water T2 relaxation times, diffusion parameters and phosphorus metabolic indices as early disease markers in patients with BMD. For this purpose, we examined these measures in fat-replaced (FR) and NFR lower leg muscles in patients with BMD and compared these values with those in healthy controls. Quantitative proton MRI (three-point Dixon, multi-spin-echo and diffusion-weighted spin-echo echo planar imaging) and 2D chemical shift imaging 31 P MRS data were acquired in 24 patients with BMD (age 18.8-66.2 years) and 13 healthy controls (age 21.3-63.6 years). Muscle fat fractions, phosphorus metabolic indices, and averages and standard deviations (SDs) of the water T2 relaxation times and diffusion tensor imaging (DTI) parameters were assessed in six individual leg muscles. Phosphodiester levels were increased in the NFR and FR tibialis anterior, FR peroneus and FR gastrocnemius lateralis muscles. No clear pattern was visible for the other metabolic indices. Increased T2 SD was found in the majority of FR muscles compared with NFR and healthy control muscles. No differences in average water T2 relaxation times or DTI indices were found between groups. Overall, our results indicate that primarily muscles that are further along in the disease process showed increases in T2 heterogeneity and changes in some metabolic indices. No clear differences were found for the DTI indices between groups.


Asunto(s)
Imagen por Resonancia Magnética , Distrofia Muscular de Duchenne/diagnóstico por imagen , Adenosina Trifosfato/metabolismo , Adolescente , Adulto , Anciano , Humanos , Concentración de Iones de Hidrógeno , Masculino , Metaboloma , Persona de Mediana Edad , Fosfocreatina/metabolismo , Fósforo/metabolismo , Agua , Adulto Joven
7.
JCO Oncol Pract ; 16(12): e1553-e1557, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32639926

RESUMEN

PURPOSE: Cancer-related fatigue is a prevalent, debilitating symptom that contributes to increased health care utilization among hospitalized patients. Music therapy is a nonpharmacological intervention that uses active (eg, singing, selecting songs) and passive (eg, listening) techniques. Preliminary evidence from small trials suggests a potential benefit for cancer-related fatigue in the inpatient setting; however, it remains unclear which techniques are most effective. METHODS: A cross-sectional mixed-methods study was performed to compare cancer-related fatigue before and after active or passive music therapy. Cancer-related fatigue was captured via the Edmonton Symptom Assessment Scale fatigue item. Patients were asked to provide postsession free-text comments. RESULTS: A total of 436 patients (mean [standard deviation] age, 62.2 [13.4] years; n = 284 [65.1%] women; n = 294 [67.4%] white; active music therapy n = 360 [82.6%]; passive music therapy n = 76 [17.4%]) with a range of primary malignancies participated. Active music therapy was associated with a 0.88-point greater reduction in cancer-related fatigue (95% CI, 0.26 to 1.51; P = .006; Cohen's D, 0.52) at postsession as compared with passive music therapy when restricting the analysis to patients who rated their baseline cancer-related fatigue as moderate to severe (ie, ≥ 4; n = 236 [54.1%]). Free-text responses confirmed higher frequencies of words describing positive affect/emotion among active music therapy participants. CONCLUSIONS: In a large sample of inpatient adults with diverse cancer disease types, active music therapy was associated with greater reduction in cancer-related fatigue and increased reporting of positive affect/emotions compared with passive music therapy. Additional research is warranted to determine the specific efficacy and underlying mechanisms of music therapy on cancer-related fatigue.


Asunto(s)
Musicoterapia , Neoplasias , Adolescente , Adulto , Estudios Transversales , Depresión , Fatiga/etiología , Fatiga/terapia , Femenino , Humanos , Neoplasias/complicaciones , Medición de Resultados Informados por el Paciente , Calidad de Vida
8.
Br J Clin Pharmacol ; 86(5): 891-902, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31833569

RESUMEN

AIMS: To test if spironolactone or dietary nitrate from beetroot juice could reduce arterial stiffness as aortic pulse wave velocity (PWVart), a potential treatment target, independently of blood pressure. METHODS: Daily spironolactone (≤50 mg) vs doxazosin (control ≤16 mg) and 70 mL beetroot juice (Beet-It ≤11 mmol nitrate) vs nitrate-depleted juice (placebo; 0 mmol nitrate) were tested in people at risk or with type-2 diabetes using a double-blind, 6-month factorial trial. Vascular indices (baseline, 12, 24 weeks) were cardiac-ankle vascular index (CAVI), a nominally pressure-independent stiffness measure (primary outcome), PWVart secondary, central systolic pressure and augmentation. Analysis was intention-to-treat, adjusted for systolic pressure differences between trial arms. RESULTS: Spironolactone did not reduce stiffness, with evidence for reduced CAVI on doxazosin rather than spironolactone (mean difference [95% confidence interval]; 0.25 [-0.3, 0.5] units, P = .080), firmer for PWVart (0.37 [0.01, 0.7] m/s, P = .045). There was no difference in systolic pressure reduction between spironolactone and doxazosin (0.7 [-4.8, 3.3] mmHg, P = .7). Circulating nitrate and nitrite increased on active vs placebo juice, with central systolic pressure lowered -2.6 [-4.5, - 0.8] mmHg, P = .007 more on the active juice, but did not reduce CAVI, PWVart or peripheral pressure. Change in nitrate and nitrite concentrations were 1.5-fold [1.1-2.2] and 2.2-fold [1.3, 3.6] higher on spironolactone than on doxazosin respectively; both P < .05. CONCLUSION: Contrary to our hypothesis, in at-risk/type 2 diabetes patients, spironolactone did not reduce arterial stiffness, rather PWVart was lower on doxazosin. Dietary nitrate elevated plasma nitrite, selectively lowering central systolic pressure, observed previously for nitrite.


Asunto(s)
Beta vulgaris , Diabetes Mellitus Tipo 2 , Nitratos , Espironolactona , Rigidez Vascular , Adulto , Anciano , Presión Sanguínea , Suplementos Dietéticos , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nitratos/uso terapéutico , Análisis de la Onda del Pulso , Espironolactona/uso terapéutico , Rigidez Vascular/efectos de los fármacos
9.
Health Technol Assess ; 23(64): 1-88, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31852579

RESUMEN

BACKGROUND: Oxaliplatin and fluoropyrimidine chemotherapy administered over 6 months is the standard adjuvant regimen for patients with high-risk stage II or III colorectal cancer. However, the regimen is associated with cumulative toxicity, characterised by chronic and often irreversible neuropathy. OBJECTIVES: To assess the efficacy of 3-month versus 6-month adjuvant chemotherapy for colorectal cancer and to compare the toxicity, health-related quality of life and cost-effectiveness of the durations. DESIGN: An international, randomised, open-label, non-inferiority, Phase III, parallel-group trial. SETTING: A total of 244 oncology clinics from six countries: UK (England, Scotland, Wales and Northern Ireland), Denmark, Spain, Sweden, Australia and New Zealand. PARTICIPANTS: Adults aged ≥ 18 years who had undergone curative resection for high-risk stage II or III adenocarcinoma of the colon or rectum. INTERVENTIONS: The adjuvant treatment regimen was either oxaliplatin and 5-fluorouracil or oxaliplatin and capecitabine, randomised to be administered over 3 or 6 months. MAIN OUTCOME MEASURES: The primary outcome was disease-free survival. Overall survival, adverse events, neuropathy and health-related quality of life were also assessed. The main cost categories were chemotherapy treatment and hospitalisation. Cost-effectiveness was assessed through incremental cost comparisons and quality-adjusted life-year gains between the options and was reported as net monetary benefit using a willingness-to-pay threshold of £30,000 per quality-adjusted life-year per patient. RESULTS: Recruitment is closed. In total, 6088 patients were randomised (3044 per group) between 27 March 2008 and 29 November 2013, with 6065 included in the intention-to-treat analyses (3-month analysis, n = 3035; 6-month analysis, n = 3030). Follow-up for the primary analysis is complete. The 3-year disease-free survival rate in the 3-month treatment group was 76.7% (standard error 0.8%) and in the 6-month treatment group was 77.1% (standard error 0.8%), equating to a hazard ratio of 1.006 (95% confidence interval 0.909 to 1.114; p-value for non-inferiority = 0.012), confirming non-inferiority for 3-month adjuvant chemotherapy. Frequent adverse events (alopecia, anaemia, anorexia, diarrhoea, fatigue, hand-foot syndrome, mucositis, sensory neuropathy, neutropenia, pain, rash, altered taste, thrombocytopenia and watery eye) showed a significant increase in grade with 6-month duration; the greatest difference was for sensory neuropathy (grade ≥ 3 was 4% for 3-month vs.16% for 6-month duration), for which a higher rate of neuropathy was seen for the 6-month treatment group from month 4 to ≥ 5 years (p < 0.001). Quality-of-life scores were better in the 3-month treatment group over months 4-6. A cost-effectiveness analysis showed 3-month treatment to cost £4881 less over the 8-year analysis period, with an incremental net monetary benefit of £7246 per patient. CONCLUSIONS: The study achieved its primary end point, showing that 3-month oxaliplatin-containing adjuvant chemotherapy is non-inferior to 6 months of the same regimen; 3-month treatment showed a better safety profile and cost less. For future work, further follow-up will refine long-term estimates of the duration effect on disease-free survival and overall survival. The health economic analysis will be updated to include long-term extrapolation for subgroups. We expect these analyses to be available in 2019-20. The Short Course Oncology Therapy (SCOT) study translational samples may allow the identification of patients who would benefit from longer treatment based on the molecular characteristics of their disease. TRIAL REGISTRATION: Current Controlled Trials ISRCTN59757862 and EudraCT 2007-003957-10. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 64. See the NIHR Journals Library website for further project information. This research was supported by the Medical Research Council (transferred to NIHR Evaluation, Trials and Studies Coordinating Centre - Efficacy and Mechanism Evaluation; grant reference G0601705), the Swedish Cancer Society and Cancer Research UK Core Clinical Trials Unit Funding (funding reference C6716/A9894).


Patients diagnosed with bowel cancer are likely to have surgery to remove the tumour. Patients diagnosed with a more advanced stage of the disease are then likely to be offered what is known as adjuvant chemotherapy ­ chemotherapy to kill any cancer cells that have already spread but cannot be seen. Adjuvant chemotherapy is usually given over 6 months using two medicines known as oxaliplatin and fluoropyrimidine. This chemotherapy has side effects of diarrhoea, nausea and vomiting, and it reduces the numbers of cells in the blood. It can also damage nerves, which causes discomfort, numbness and tingling; in some cases, this can go on for years. These side effects are more likely to develop with longer treatment. This study looked at whether or not shortening the time over which patients were given oxaliplatin and fluoropyrimidine chemotherapy reduced its effectiveness. In this large study of over 6000 patients, half of the patients were allocated by chance to be treated for 3 months and the other half to be treated for 6 months. Reducing the time that patients had chemotherapy from 6 months to 3 months did not make the treatment less effective. When patients treated with chemotherapy over 3 months were compared with those treated over 6 months, 77% of patients in both groups were well with no detectable disease 3 years after surgery. Patients were less likely to get side effects with 3-month chemotherapy. In particular, the chance of persistent long-term nerve damage was lower, resulting in patients with 3-month chemotherapy having better health-related quality of life. Overall, the study showed that 3-month adjuvant chemotherapy for patients with bowel cancer is as effective as 6-month adjuvant chemotherapy and causes fewer side effects.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Capecitabina/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Supervivencia sin Enfermedad , Fluorouracilo/uso terapéutico , Oxaliplatino/uso terapéutico , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/economía , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Australia , Quimioterapia Adyuvante , Análisis Costo-Beneficio/economía , Europa (Continente) , Femenino , Estudios de Seguimiento , Humanos , Internacionalidad , Masculino , Persona de Mediana Edad , Años de Vida Ajustados por Calidad de Vida , Evaluación de la Tecnología Biomédica , Factores de Tiempo , Reino Unido
10.
Br J Clin Pharmacol ; 85(7): 1443-1453, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30845346

RESUMEN

AIMS: Dietary inorganic nitrate (NO3- ) lowers peripheral blood pressure (BP) in healthy volunteers, but lacks such effect in individuals with, or at risk of, type 2 diabetes mellitus (T2DM). Whilst this is commonly assumed to be a consequence of chronic hyperglycaemia/hyperinsulinaemia, we hypothesized that acute physiological elevations in plasma [glucose]/[insulin] blunt the haemodynamic responses to NO3- , a pertinent question for carbohydrate-rich Western diets. METHODS: We conducted an acute, randomized, placebo-controlled, double-blind, crossover study on the haemodynamic and metabolic effects of potassium nitrate (8 or 24 mmol KNO3 ) vs. potassium chloride (KCl; placebo) administered 1 hour prior to an oral glucose tolerance test in 33 healthy volunteers. RESULTS: Compared to placebo, there were no significant differences in systolic or diastolic BP (P = 0.27 and P = 0.30 on ANOVA, respectively) with KNO3 , nor in pulse wave velocity or central systolic BP (P = 0.99 and P = 0.54 on ANOVA, respectively). Whilst there were significant elevations from baseline for plasma [glucose] and [C-peptide], no differences between interventions were observed. A significant increase in plasma [insulin] was observed with KNO3 vs. KCl (n = 33; P = 0.014 on ANOVA) with the effect driven by the high-dose cohort (24 mmol, n = 13; P < 0.001 on ANOVA; at T = 0.75 h mean difference 210.4 pmol/L (95% CI 28.5 to 392.3), P = 0.012). CONCLUSIONS: In healthy adults, acute physiological elevations of plasma [glucose] and [insulin] result in a lack of BP-lowering with dietary nitrate. The increase in plasma [insulin] without a corresponding change in [C-peptide] or [glucose] suggests that high-dose NO3- decreases insulin clearance. A likely mechanism is via NO-dependent inhibition of insulin-degrading enzyme.


Asunto(s)
Glucemia/metabolismo , Presión Sanguínea/efectos de los fármacos , Insulina/sangre , Nitratos/farmacología , Compuestos de Potasio/farmacología , Adulto , Estudios Cruzados , Método Doble Ciego , Femenino , Glucosa/administración & dosificación , Glucosa/metabolismo , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Nitratos/administración & dosificación , Óxido Nítrico/metabolismo , Cloruro de Potasio/administración & dosificación , Cloruro de Potasio/farmacología , Compuestos de Potasio/administración & dosificación , Análisis de la Onda del Pulso , Adulto Joven
11.
Br J Clin Pharmacol ; 85(1): 169-180, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30294825

RESUMEN

AIMS: The aims of the present study were to explore whether a long-term intervention with dietary nitrate [(NO3- ), a potential tolerance-free source of beneficial vasoactive nitric oxide] and spironolactone (to oppose aldosterone's potential deleterious cardiovascular effects) improve cardiac structure/function, independently of blood pressure (BP), in patients with/at risk of type 2 diabetes (a population at risk of heart failure). METHODS: A subsample of participants in our double-blind, randomized, factorial-design intervention (VaSera) trial of active beetroot juice as a nitrate source (≤11.2 mmol) or placebo (nitrate depleted) beetroot juice, and either ≤50 mg spironolactone or ≤16 mg doxazosin (control), had transthoracic cardiac ultrasounds at baseline (n = 105), and at 3 months and 6 months (n = 87) after the start of the intervention. Analysis was by modified intent-to-treat. RESULTS: Nitrate-containing juice (n = 40) decreased left ventricular (LV) end-diastolic volume {-6.3 [95% confidence interval (CI) -11.1, -1.6] ml} and end-systolic volume [-3.2 (95% CI -5.9, -0.5) ml], and increased end-diastolic mass/volume ratio [+0.04 (95% CI 0.00, 0.07)], relative to placebo juice (n = 47). Spironolactone (n = 44) reduced relative wall thickness compared with doxazosin (n = 43) [-0.01 (95% CI -0.02, -0.00)]. Although spironolactone reduced LV mass index relative to baseline [-1.48 (95% CI -2.08, -0.88) g m-2.7 ], there was no difference vs. doxazosin [-0.85 (95% CI -1.76, 0.05) g m-2.7 ]. Spironolactone also decreased the E/A ratio [-0.12 (95% CI -0.19, -0.04)] and increased S' (a tissue-Doppler systolic function index) by 0.52 (95% CI 0.05, 1.0) cm s-1 . BP did not differ between the juices, or between the drugs. CONCLUSIONS: Six months' dietary nitrate decreased LV volumes ~5%, representing new, sustained, BP-independent benefits on cardiac structure, extending mechanisms characterized in preclinical models of heart failure. Spironolactone's effects on cardiac remodelling and systolic-diastolic function, although confirmatory, were independent of BP.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Insuficiencia Cardíaca/prevención & control , Corazón/efectos de los fármacos , Nitratos/administración & dosificación , Espironolactona/administración & dosificación , Adulto , Anciano , Beta vulgaris/química , Presión Sanguínea/efectos de los fármacos , Método Doble Ciego , Doxazosina/administración & dosificación , Ecocardiografía , Femenino , Jugos de Frutas y Vegetales , Corazón/diagnóstico por imagen , Insuficiencia Cardíaca/etiología , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Placebos/administración & dosificación , Análisis de la Onda del Pulso , Resultado del Tratamiento , Rigidez Vascular/efectos de los fármacos
12.
Lancet Oncol ; 19(4): 562-578, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29611518

RESUMEN

BACKGROUND: 6 months of oxaliplatin-containing chemotherapy is usually given as adjuvant treatment for stage 3 colorectal cancer. We investigated whether 3 months of oxaliplatin-containing chemotherapy would be non-inferior to the usual 6 months of treatment. METHODS: The SCOT study was an international, randomised, phase 3, non-inferiority trial done at 244 centres. Patients aged 18 years or older with high-risk stage II and stage III colorectal cancer underwent central randomisation with minimisation for centre, choice of regimen, sex, disease site, N stage, T stage, and the starting dose of capecitabine. Patients were assigned (1:1) to receive 3 months or 6 months of adjuvant oxaliplatin-containing chemotherapy. The chemotherapy regimens could consist of CAPOX (capecitabine and oxaliplatin) or FOLFOX (bolus and infused fluorouracil with oxaliplatin). The regimen was selected before randomisation in accordance with choices of the patient and treating physician. The primary study endpoint was disease-free survival and the non-inferiority margin was a hazard ratio of 1·13. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who started study treatment. This trial is registered with ISRCTN, number ISRCTN59757862, and follow-up is continuing. FINDINGS: 6088 patients underwent randomisation between March 27, 2008, and Nov 29, 2013. The intended treatment was FOLFOX in 1981 patients and CAPOX in 4107 patients. 3044 patients were assigned to 3 month group and 3044 were assigned to 6 month group. Nine patients in the 3 month group and 14 patients in the 6 month group did not consent for their data to be used, leaving 3035 patients in the 3 month group and 3030 patients in the 6 month group for the intention-to-treat analyses. At the cutoff date for analysis, there had been 1482 disease-free survival events, with 740 in the 3 month group and 742 in the 6 month group. 3 year disease-free survival was 76·7% (95% CI 75·1-78·2) for the 3 month group and 77·1% (75·6-78·6) for the 6 month group, giving a hazard ratio of 1·006 (0·909-1·114, test for non-inferiority p=0·012), significantly below the non-inferiority margin. Peripheral neuropathy of grade 2 or worse was more common in the 6 month group (237 [58%] of 409 patients for the subset with safety data) than in the 3 month group (103 [25%] of 420) and was long-lasting and associated with worse quality of life. 1098 serious adverse events were reported (492 reports in the 3 month group and 606 reports in the 6 month group) and 32 treatment-related deaths occurred (16 in each group). INTERPRETATION: In the whole study population, 3 months of oxaliplatin-containing adjuvant chemotherapy was non-inferior to 6 months of the same therapy for patients with high-risk stage II and stage III colorectal cancer and was associated with reduced toxicity and improved quality of life. Despite the fact the study was underpowered, these data suggest that a shorter duration leads to similar survival outcomes with better quality of life and thus might represent a new standard of care. FUNDING: Medical Research Council, Swedish Cancer Society, NETSCC, and Cancer Research UK.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Colorrectales/tratamiento farmacológico , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Anciano , Capecitabina/administración & dosificación , Quimioterapia Adyuvante/efectos adversos , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/cirugía , Supervivencia sin Enfermedad , Femenino , Fluorouracilo/administración & dosificación , Humanos , Leucovorina/administración & dosificación , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino/administración & dosificación , Enfermedades del Sistema Nervioso Periférico/inducido químicamente , Calidad de Vida , Tasa de Supervivencia , Factores de Tiempo
13.
J Neuromuscul Dis ; 4(1): 53-58, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28269793

RESUMEN

BACKGROUND: Duchenne muscular dystrophy (DMD) is caused by the absence of dystrophin. DMD is associated with specific learning and behavioural disabilities. In the brain, dystrophin is associated with GABAA receptors and aquaporin-4 in neurons and astrocytes, respectively, but little is known about its function. OBJECTIVE AND METHODS: In this study we aimed to compare the biochemical composition between patients and healthy controls in brain regions that are naturally rich in dystrophin using magnetic resonance spectroscopy. Given previous conflicting results obtained at clinical field strengths, we obtained data using a 7 Tesla system with associated higher signal-to-noise ratio and spectral resolution. RESULTS: Results indicated unchanged biochemical composition in all regions investigated, and increased variance in glutamate in the frontal cortex.


Asunto(s)
Encéfalo/diagnóstico por imagen , Distrofia Muscular de Duchenne/diagnóstico por imagen , Adolescente , Acuaporina 4/metabolismo , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encéfalo/metabolismo , Estudios de Casos y Controles , Cerebelo/diagnóstico por imagen , Cerebelo/metabolismo , Niño , Colina/metabolismo , Creatina/metabolismo , Lóbulo Frontal/diagnóstico por imagen , Lóbulo Frontal/metabolismo , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Hipocampo/diagnóstico por imagen , Hipocampo/metabolismo , Humanos , Inositol/metabolismo , Masculino , Distrofia Muscular de Duchenne/metabolismo , Espectroscopía de Protones por Resonancia Magnética , Receptores de GABA-A/metabolismo
14.
IEEE Trans Biomed Eng ; 63(11): 2390-2395, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-26929023

RESUMEN

GOAL: To design and characterize a new set-up for dual nuclei MRI combining an annular dielectric resonator filled with high permittivity material for phosphorous (31P) and a traveling wave antenna for proton imaging. METHODS: Recent studies have shown that an annular cylinder filled with water can serve as dielectric resonator for proton MRI of the extremities at 7 T. Using a very high permittivity material such as BaTiO3, this type of dielectric resonator can potentially be designed for lower gyromagnetic ratio nuclei. Combining this with a remote antenna for proton imaging, an alternative method for dual frequency imaging at ultrahigh field has been implemented. RESULTS: 3D electromagnetic simulations were performed to examine the efficiency of the dielectric resonator. The new dielectric resonator was constructed for 31P acquisition at 121 MHz on a human 7 T MRI system. Phantom and in vivo scans demonstrated the feasibility of the setup, although the current sensitivity of the dielectric resonator is only half that of an equivalently sized birdcage. CONCLUSION: The new approach offers a simple implementation for dual nuclei imaging at ultrahigh field, with several possibilities for further increases in sensitivity. SIGNIFICANCE: Utilizing high permittivity materials enables very simple designs for high field RF coils: in the current configuration the interactions between the proton and phosphorous resonators are very low.


Asunto(s)
Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Fósforo/química , Simulación por Computador , Conductividad Eléctrica , Diseño de Equipo , Humanos , Fantasmas de Imagen
15.
Proc Natl Acad Sci U S A ; 111(42): 15072-7, 2014 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-25288762

RESUMEN

Necroptosis is considered to be complementary to the classical caspase-dependent programmed cell death pathway, apoptosis. The pseudokinase Mixed Lineage Kinase Domain-Like (MLKL) is an essential effector protein in the necroptotic cell death pathway downstream of the protein kinase Receptor Interacting Protein Kinase-3 (RIPK3). How MLKL causes cell death is unclear, however RIPK3-mediated phosphorylation of the activation loop in MLKL trips a molecular switch to induce necroptotic cell death. Here, we show that the MLKL pseudokinase domain acts as a latch to restrain the N-terminal four-helix bundle (4HB) domain and that unleashing this domain results in formation of a high-molecular-weight, membrane-localized complex and cell death. Using alanine-scanning mutagenesis, we identified two clusters of residues on opposing faces of the 4HB domain that were required for the 4HB domain to kill cells. The integrity of one cluster was essential for membrane localization, whereas MLKL mutations in the other cluster did not prevent membrane translocation but prevented killing; this demonstrates that membrane localization is necessary, but insufficient, to induce cell death. Finally, we identified a small molecule that binds the nucleotide binding site within the MLKL pseudokinase domain and retards MLKL translocation to membranes, thereby preventing necroptosis. This inhibitor provides a novel tool to investigate necroptosis and demonstrates the feasibility of using small molecules to target the nucleotide binding site of pseudokinases to modulate signal transduction.


Asunto(s)
Apoptosis , Necrosis , Proteínas Quinasas/metabolismo , Adenosina Trifosfato/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Sitios de Unión , Membrana Celular/metabolismo , Activación Enzimática , Concentración 50 Inhibidora , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Mutación , Fosforilación , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Transporte de Proteínas , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido
16.
Free Radic Biol Med ; 65: 1521-1532, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23806384

RESUMEN

Ingestion of vegetables rich in inorganic nitrate has emerged as an effective method, via the formation of a nitrite intermediate, for acutely elevating vascular NO levels. As such a number of beneficial effects of dietary nitrate ingestion have been demonstrated including the suggestion that platelet reactivity is reduced. In this study we investigated whether inorganic nitrate supplementation might also reduce platelet reactivity in healthy volunteers and have determined the mechanisms involved in the effects seen. We conducted two randomised crossover studies each in 24 (12 of each sex) healthy subjects assessing the acute effects of dietary nitrate (250 ml beetroot juice) or potassium nitrate capsules (KNO3, 8 mmol) vs placebo control on platelet reactivity. Inorganic nitrate ingested either from a dietary source or via supplementation raised circulating nitrate and nitrite levels in both sexes and attenuated ex vivo platelet aggregation responses to ADP and, albeit to a lesser extent, collagen but not epinephrine in male but not female volunteers. These inhibitory effects were associated with a reduced platelet P-selectin expression and elevated platelet cGMP levels. In addition, we show that nitrite reduction to NO occurs at the level of the erythrocyte and not the platelet. In summary, our results demonstrate that inorganic nitrate ingestion, whether via the diet or through supplementation, causes a modest decrease in platelet reactivity in healthy males but not females. Our studies provide strong support for further clinical trials investigating the potential of dietary nitrate as an adjunct to current antiplatelet therapies to prevent atherothrombotic complications. Moreover, our observations highlight a previously unknown sexual dimorphism in platelet reactivity to NO and intimate a greater dependence of males on the NO-soluble guanylate cyclase pathway in limiting thrombotic potential.


Asunto(s)
Plaquetas/metabolismo , Nitratos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Compuestos de Potasio/farmacología , Adolescente , Adulto , Beta vulgaris , Enfermedades Cardiovasculares/tratamiento farmacológico , Colágeno/farmacología , Estudios Cruzados , GMP Cíclico/biosíntesis , Dieta , Suplementos Dietéticos , Epinefrina/farmacología , Eritrocitos/metabolismo , Femenino , Guanilato Ciclasa/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Nitratos/administración & dosificación , Óxido Nítrico/metabolismo , Selectina-P/biosíntesis , Inhibidores de Agregación Plaquetaria/administración & dosificación , Compuestos de Potasio/administración & dosificación , Factores Sexuales , Verduras , Adulto Joven
17.
Br J Clin Pharmacol ; 75(3): 677-96, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22882425

RESUMEN

The discovery that dietary (inorganic) nitrate has important vascular effects came from the relatively recent realization of the 'nitrate-nitrite-nitric oxide (NO) pathway'. Dietary nitrate has been demonstrated to have a range of beneficial vascular effects, including reducing blood pressure, inhibiting platelet aggregation, preserving or improving endothelial dysfunction, enhancing exercise performance in healthy individuals and patients with peripheral arterial disease. Pre-clinical studies with nitrate or nitrite also show the potential to protect against ischaemia-reperfusion injury and reduce arterial stiffness, inflammation and intimal thickness. However, there is a need for good evidence for hard endpoints beyond epidemiological studies. Whilst these suggest reduction in cardiovascular risk with diets high in nitrate-rich vegetables (such as a Mediterranean diet), others have suggested possible small positive and negative associations with dietary nitrate and cancer, but these remain unproven. Interactions with other nutrients, such as vitamin C, polyphenols and fatty acids may enhance or inhibit these effects. In order to provide simple guidance on nitrate intake from different vegetables, we have developed the Nitrate 'Veg-Table' with 'Nitrate Units' [each unit being 1 mmol of nitrate (62 mg)] to achieve a nitrate intake that is likely to be sufficient to derive benefit, but also to minimize the risk of potential side effects from excessive ingestion, given the current available evidence. The lack of data concerning the long term effects of dietary nitrate is a limitation, and this will need to be addressed in future trials.


Asunto(s)
Beta vulgaris , Sistema Cardiovascular/metabolismo , Dieta , Nitratos/sangre , Óxido Nítrico/sangre , Nitritos/sangre , Hojas de la Planta/metabolismo , Verduras/metabolismo , Presión Sanguínea/fisiología , Vasos Sanguíneos/metabolismo , Enfermedades Cardiovasculares/dietoterapia , Enfermedades Cardiovasculares/metabolismo , Sistema Cardiovascular/efectos de los fármacos , Humanos , Factores de Riesgo
19.
Hypertension ; 56(2): 274-81, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20585108

RESUMEN

Ingestion of dietary (inorganic) nitrate elevates circulating and tissue levels of nitrite via bioconversion in the entero-salivary circulation. In addition, nitrite is a potent vasodilator in humans, an effect thought to underlie the blood pressure-lowering effects of dietary nitrate (in the form of beetroot juice) ingestion. Whether inorganic nitrate underlies these effects and whether the effects of either naturally occurring dietary nitrate or inorganic nitrate supplementation are dose dependent remain uncertain. Using a randomized crossover study design, we show that nitrate supplementation (KNO(3) capsules: 4 versus 12 mmol [n=6] or 24 mmol of KNO(3) (1488 mg of nitrate) versus 24 mmol of KCl [n=20]) or vegetable intake (250 mL of beetroot juice [5.5 mmol nitrate] versus 250 mL of water [n=9]) causes dose-dependent elevation in plasma nitrite concentration and elevation of cGMP concentration with a consequent decrease in blood pressure in healthy volunteers. In addition, post hoc analysis demonstrates a sex difference in sensitivity to nitrate supplementation dependent on resting baseline blood pressure and plasma nitrite concentration, whereby blood pressure is decreased in male volunteers, with higher baseline blood pressure and lower plasma nitrite concentration but not in female volunteers. Our findings demonstrate dose-dependent decreases in blood pressure and vasoprotection after inorganic nitrate ingestion in the form of either supplementation or by dietary elevation. In addition, our post hoc analyses intimate sex differences in nitrate processing involving the entero-salivary circulation that are likely to be major contributing factors to the lower blood pressures and the vasoprotective phenotype of premenopausal women.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Nitratos/farmacología , Óxido Nítrico/fisiología , Compuestos de Potasio/farmacología , Arteria Braquial/anatomía & histología , Arteria Braquial/efectos de los fármacos , Arteria Braquial/fisiología , Enfermedades Cardiovasculares/epidemiología , Estudios Cruzados , GMP Cíclico/sangre , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hiperemia/fisiopatología , Hipertensión/complicaciones , Hipotensión/inducido químicamente , Estilo de Vida , Masculino , Nitratos/sangre , Nitritos/sangre , Nitritos/farmacología , Postura , Cloruro de Potasio/farmacología , Prevalencia , Distribución Aleatoria , Factores de Riesgo , Caracteres Sexuales , Sístole/efectos de los fármacos , Sístole/fisiología
20.
Nat Chem Biol ; 5(12): 865-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19915529

RESUMEN

Inorganic nitrate and nitrite from endogenous or dietary sources are metabolized in vivo to nitric oxide (NO) and other bioactive nitrogen oxides. The nitrate-nitrite-NO pathway is emerging as an important mediator of blood flow regulation, cell signaling, energetics and tissue responses to hypoxia. The latest advances in our understanding of the biochemistry, physiology and therapeutics of nitrate, nitrite and NO were discussed during a recent 2-day meeting at the Nobel Forum, Karolinska Institutet in Stockholm.


Asunto(s)
Nitratos/metabolismo , Nitratos/uso terapéutico , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Nitritos/uso terapéutico , Animales , Dieta , Metabolismo Energético , Humanos , Mitocondrias/metabolismo , Nitratos/administración & dosificación , Nitritos/administración & dosificación , Transducción de Señal
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