190 results on '"Nicholls MG"'
Search Results
2. The renin-angiotensin system in the year 2000
- Author
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Nicholls, MG and Robertson, JIS
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- 2000
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3. The importance of the renin-angiotensin system in cardiovascular disease
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Nicholls, MG, Richards, AM, and Agarwal, M
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- 1998
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4. Effect of lacidipine on blood pressure, vasoactive hormones, and haemorheology in elderly patients with essential hypertension
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Shand, BI, Gilchrist, NL, Nicholls, MG, and Caesar, M
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- 2000
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5. Increased plasma norepinephrine levels in previously pre-eclamptic women
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Nicholls Mg, Timothy G. Yandle, Per-Henrik Groop, Risto Kaaja, Katja Lampinen, and Mats Rönnback
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Adult ,medicine.medical_specialty ,Sympathetic nervous system ,Sympathetic Nervous System ,Time Factors ,Diastole ,Vasodilation ,Blood Pressure ,Norepinephrine ,Insulin resistance ,Pre-Eclampsia ,Heart Rate ,Pregnancy ,Risk Factors ,Internal medicine ,Heart rate ,Internal Medicine ,medicine ,Humans ,Endothelial dysfunction ,Endothelin-1 ,business.industry ,Postpartum Period ,ta3121 ,medicine.disease ,Blood pressure ,medicine.anatomical_structure ,Endocrinology ,Cardiovascular Diseases ,Case-Control Studies ,Hypertension ,Female ,Metabolic syndrome ,Insulin Resistance ,business ,Biomarkers - Abstract
A history of pre-eclampsia increases the risk of cardiovascular morbidity by mechanisms yet unknown. The aim of the present study was to assess whether plasma norepinephrine (NE) levels are increased 5–6 years after pre-eclamptic pregnancy and to investigate associations with pathophysiological mechanisms of cardiovascular disease: insulin sensitivity, vascular function and arterial pressure. A total of 28 women with previous pre-eclampsia and 20 controls were examined. Blood pressure (BP) and plasma levels of NE and endothelin-1 (ET-1) were measured at rest and after standing for 5 min. Insulin sensitivity was assessed with minimal model analysis and vascular function was assessed using venous occlusion plethysmography and pulse wave analysis. Twenty-four-hour BP measurements were carried out. Women with previous pre-eclampsia had higher levels of NE at rest (P=0.02), which did not associate significantly with insulin sensitivity or overall vasodilatory capacity. The 24-h mean of systolic and diastolic blood pressures (BPs) and heart rate did not differ between the groups (P=0.30, P=0.10 and P=0.46, respectively), and there was no significant association with NE levels. ET-1 levels were similar between the groups, but a positive correlation with systolic (P=0.04) and diastolic (P=0.03) BPs in the upright position was shown in the patient group. Increased levels of plasma NE are sustained in women with previous pre-eclampsia and may contribute to the increased risk for cardiovascular disease in these women.
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- 2014
6. A man with severe, transient hypertension due to acute renal infarction
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Fay, MF, Nicholls, MG, and Richards, AM
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- 1999
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7. Hypertension, hypertrophy, heart failure
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Nicholls Mg
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Male ,medicine.medical_specialty ,Heart disease ,MEDLINE ,Reviews ,Concentric hypertrophy ,Muscle hypertrophy ,Internal medicine ,medicine ,Humans ,Antihypertensive Agents ,Heart Failure ,business.industry ,Middle Aged ,Prognosis ,medicine.disease ,Heart failure ,Pathophysiology of hypertension ,Hypertension complications ,Hypertension ,Cardiology ,Female ,Hypertrophy, Left Ventricular ,Cardiology and Cardiovascular Medicine ,Complication ,business - Published
- 1996
8. Hemodynamic and hormonal actions of adrenomedullin
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Nicholls Mg
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Agonist ,medicine.medical_specialty ,Cardiotonic Agents ,Physiology ,medicine.drug_class ,Immunology ,Biophysics ,Blood Pressure ,Heart failure ,Biochemistry ,Hypopituitarism ,Norepinephrine (medication) ,chemistry.chemical_compound ,Adrenomedullin ,Norepinephrine ,Heart Rate ,Internal medicine ,Renin–angiotensin system ,Renin ,medicine ,Animals ,Humans ,General Pharmacology, Toxicology and Pharmaceutics ,lcsh:QH301-705.5 ,Aldosterone ,Heart Failure ,lcsh:R5-920 ,business.industry ,General Neuroscience ,Endothelins ,Hemodynamics ,Cell Biology ,General Medicine ,medicine.disease ,Angiotensin II ,Blood pressure ,Endocrinology ,chemistry ,lcsh:Biology (General) ,Hypertension ,business ,lcsh:Medicine (General) ,Peptides ,Atrial Natriuretic Factor ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
Adrenomedullin, a 52-amino acid residue peptide, has numerous biological actions which are of potential importance to cardiovascular homeostasis, growth and development of cardiovascular tissues and bone, prevention of infection, and regulation of body fluid and electrolyte balance. Studies in man using intravenous infusion of the peptide have demonstrated that, at plasma levels detected after myocardial infarction or in heart failure, adrenomedullin reduces arterial pressure, increases heart rate and cardiac output, and activates the sympathetic and renin-angiotensin systems but suppresses aldosterone. The thresholds for these responses differ, being lower under some experimental circumstances for arterial pressure than for the other biological effects. Adrenomedullin administration inhibits the pressor and aldosterone-stimulating action of angiotensin II in man. By contrast, the pressor effect of norepinephrine is little altered by concomitant adrenomedullin administration. Although in the absence of a safe, specific antagonist of the actions of endogenous adrenomedullin it is difficult to be certain about the physiological and pathophysiological importance of this peptide in man, current evidence suggests that it serves to protect against cardiovascular overload and injury. Hope has been expressed that adrenomedullin or an agonist specific for adrenomedullin receptors might find a place in the treatment of cardiovascular disorders.
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- 2004
9. Malignant Phaeochromocytoma with High Circulating DOPA, and Clonidine-Suppressible Noradrenaline
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McClean Dr, Nicholls Mg, Yandle Tg, and Sinclair Lm
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Male ,medicine.medical_specialty ,Urinary system ,Adrenal Gland Neoplasms ,Pheochromocytoma ,Essential hypertension ,Clonidine ,Norepinephrine ,chemistry.chemical_compound ,Urinary levels ,Internal medicine ,Internal Medicine ,Humans ,Medicine ,Aged ,business.industry ,Healthy subjects ,Malignant phaeochromocytoma ,General Medicine ,medicine.disease ,Dihydroxyphenylalanine ,Endocrinology ,chemistry ,Catecholamine ,Cardiology and Cardiovascular Medicine ,business ,Adrenergic alpha-Agonists ,medicine.drug - Abstract
Phaeochromocytoma, “perhaps the most fascinating of all tumours” [1], can present with a broad range of clinical manifestations [2]. Once suspected, the biochemical diagnosis is straightforward in most patients since plasma and urinary levels of noradrenaline and/or adrenaline, and urinary metabolites are well above those encountered in healthy subjects or patients with essential hypertension [3,4]. Exceptions to this general rule are well known, however, hence suppression tests have found favour, particularly in cases where catecholamine levels are within, or close to, the normal range [5–7]. We present a unique patient with malignant phaeochromocytoma whose plasma noradrenaline levels were in the high-normal range, and suppressed normally with clonidine administration. He had extremely high circulating levels of dihydroxyphenylalanine (dopa) which were not affected by clonidine, and different patterns of catecholamine concentrations in tumour tissue and plasma.
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- 1995
10. B-type natriuretic peptide signal peptide circulates in human blood: evaluation as a potential biomarker of cardiac ischemia.
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Siriwardena M, Kleffmann T, Ruygrok P, Cameron VA, Yandle TG, Nicholls MG, Richards AM, and Pemberton CJ
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- 2010
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11. Introduction of metoprolol increases plasma B-type cardiac natriuretic peptides in mild, stable heart failure.
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Davis ME, Richards AM, Nicholls MG, Yandle TG, Frampton CM, and Troughton RW
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- 2006
12. Different effects of antihypertensive therapies based on losartan or atenolol on ultrasound and biochemical markers of myocardial fibrosis: results of a randomized trial.
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Ciulla MM, Paliotti R, Esposito A, Diez J, López B, Dahlöf B, Nicholls MG, Smith RD, Gilles L, Magrini F, Zanchetti A, Ciulla, Michele M, Paliotti, Roberta, Esposito, Arturo, Dìez, Javier, López, Begoña, Dahlöf, Björn, Nicholls, M Gary, Smith, Ronald D, and Gilles, Leen
- Published
- 2004
13. B-type natriuretic peptides and ejection fraction for prognosis after myocardial infarction.
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Richards AM, Nicholls MG, Espiner EA, Lainchbury JG, Troughton RW, Elliott J, Frampton C, Turner J, Crozier IG, and Yandle TG
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- 2003
14. Enalapril in heart failure.
- Author
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Nicholls, MG, Ikram, H, Espiner, EA, Webster, MW, and Fitzpatrick, MA
- Abstract
Serum MK-422 and plasma angiotensin converting enzyme activity were measured during the introduction of enalapril therapy in eight patients with heart failure. In a second study of 16 patients, we recorded exercise tolerance, clinical status and haemodynamics before and after 12 weeks of placebo or enalapril treatment. Increasing doses of enalapril gave step-wise increments in serum MK-422. Plasma converting enzyme activity remained low for at least 24 h after each dose of enalapril (5, 10 and 20 mg). Compared to placebo patients (n = 8), those receiving enalapril (n = 8) tended to improve their exercise performance and clinical status, and showed a fall in right heart pressures after 12 weeks of treatment. [ABSTRACT FROM AUTHOR]
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- 1984
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15. Hormonal effects and metabolic clearance rate of the enkephalin analogue DAMME in man.
- Author
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Gilchrist, N, Bolton, JE, Donald, RA, Livesey, JH, Roud, HK, and Nicholls, MG
- Abstract
The enkephalin analogue DAMME (0.25 mg) and normal saline were administered by slow intravenous injection to six normal male subjects in a double-blind crossover study. Plasma DAMME concentrations were measured by a specific radioimmunoassay. A significant rise in plasma growth hormone and prolactin and a significant fall in plasma corticotrophin and cortisol concentrations were observed. The fall in pancreatic polypeptide concentration just failed to reach significance. No significant changes were observed in insulin, glucagon, glucose, adrenaline and noradrenaline. Serum concentrations of DAMME were initially high (greater than 6.7 nmol/1) corresponding with the observed maximum plasma growth hormone and prolactin responses. The serum DAMME concentration was readily detectable when plasma growth hormone and prolactin had returned to control levels, but corticotrophin and cortisol were still significantly depressed. [ABSTRACT FROM AUTHOR]
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- 1983
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16. Age-Related Effects of Diuretics in Hypertensive Subjects
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Nicholls Mg
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Pharmacology ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Renal function ,Disease ,medicine.disease ,Essential hypertension ,Hypokalemia ,Internal medicine ,Age related ,Medicine ,Azotemia ,Diuretic ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Hyponatremia - Abstract
Although the literature on diuretic therapy for essential hypertension is abundant, little attention has been directed to age-related responses, and dose-response information in young compared to elderly patients is lacking. The pharmacokinetic characteristics of some diuretics are modified in the elderly, and these appear to be accounted for by an age-related decline in renal function. Whereas some studies have suggested that the antihypertensive effect of diuretics is enhanced in the elderly, the few "satisfactory" trials available have not confirmed earlier observations. Contrary to first impressions, symptomatic side effects with diuretics are not more frequent in older patients and some trials suggest they are less frequent than in younger hypertensive subjects. Of the biochemical changes induced by diuretics, azotemia, hyponatremia and perhaps hypokalemia appear more frequently in the elderly. The elderly, especially those with underlying cardiac disease, may be more susceptible to the arrhythmogenic effect of diuretics than healthy younger patients, but the evidence is suggestive rather than definitive. It was concluded from this survey of the literature that our knowledge of the age-related effects of diuretics in the treatment of essential hypertension is fragmentary and far from complete.
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- 1988
17. B-type natriuretic peptide or amino-terminal pro-B-type natriuretic peptide-guided treatment of heart failure: what is the next STEP?
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Troughton RW and Nicholls MG
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- 2011
18. Angiotensin-Converting Enzyme Inhibitors in Congestive Heart Failure
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Nicholls Mg and Arakawa K
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Heart Failure ,Pharmacology ,medicine.medical_specialty ,biology ,business.industry ,Angiotensin-Converting Enzyme Inhibitors ,Arrhythmias, Cardiac ,Angiotensin-converting enzyme ,Kidney ,medicine.disease ,Placebo ,Heart failure ,Potassium ,medicine ,biology.protein ,Etiology ,Humans ,In patient ,Diuretics ,Cardiology and Cardiovascular Medicine ,Intensive care medicine ,business ,Prospective cohort study ,Heterogeneous disorder - Abstract
The angiotensin-converting enzyme (ACE) inhibitors are of proven benefit in patients with severe grades of heart failure who are already on baseline treatment with diuretics. Under these circumstances they have been shown, in controlled prospective studies, to be superior to placebo and also to other vasodilators. Many areas of uncertainty remain, however, and some of these were addressed at the Cambridge Conference. This brief overview summarizes the views expressed by delegates. It was recognized that heart failure is a heterogeneous disorder in relation to etiology, severity, outlook, and associated clinical and biochemical abnormalities. Each patient, therefore, must be treated on an individual basis, and general rules will need to be modified according to the particular requirements of the individual. No formal attempt was made to assess preferences for individual ACE inhibitors in heart failure, and indeed this would have been impractical because many clinicians were familiar with only one agent.
- Published
- 1987
19. Inhibition of the renin-angiotensin system in the treatment of heart failure: why, when, and where
- Author
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Nicholls Mg
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Risk ,medicine.medical_specialty ,Digoxin ,Vasodilation ,Angiotensin-Converting Enzyme Inhibitors ,Kidney ,Renin-Angiotensin System ,Dogs ,Internal medicine ,Renin–angiotensin system ,medicine ,Animals ,Humans ,Myocardial infarction ,Diuretics ,Pharmacology ,Heart Failure ,Angiotensin II receptor type 1 ,biology ,business.industry ,Angiotensin II ,Hemodynamics ,Angiotensin-converting enzyme ,medicine.disease ,Blockade ,Heart failure ,biology.protein ,Cardiology ,Drug Therapy, Combination ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Abstract
Angiotensin converting enzyme inhibitors can be recommended in the treatment of severe cardiac failure (New York Heart Association Functional Class III or VI) where they are probably superior to other vasodilators. Their use should be considered when routine therapy with diuretics and digoxin has failed to ameliorate symptoms. Whether they can be recommended also for mild heart failure and whether the benefits outweigh any risks associated with long-term blockade of the renin-angiotensin system are questions that remain to be answered. Their use in hypertension and early in acute myocardial infarction might prevent the development of heart failure, but appropriate studies in man are awaited.
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- 1985
20. No Evidence of Failure of the Renin-Angiotensin System in Focal Glomerulosclerosis in Man
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Nicholls Mg, Espiner Ea, and Swainson Cp
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Male ,medicine.medical_specialty ,Glomerulosclerosis, Focal Segmental ,business.industry ,Posture ,Blood Pressure ,Renin-Angiotensin System ,Glomerulonephritis ,Endocrinology ,Focal glomerulosclerosis ,Internal medicine ,Renin ,Renin–angiotensin system ,medicine ,Humans ,Female ,business ,Aldosterone - Published
- 1986
21. Biomarker-guided treatment of heart failure still waiting for a definitive answer.
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Troughton RW, Frampton CM, and Nicholls MG
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- 2010
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22. N-terminal pro-B-type natriuretic peptide-guided treatment for chronic heart failure: results from the BATTLESCARRED (NT-proBNP-Assisted Treatment To Lessen Serial Cardiac Readmissions and Death) trial.
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Lainchbury JG, Troughton RW, Strangman KM, Frampton CM, Pilbrow A, Yandle TG, Hamid AK, Nicholls MG, and Richards AM
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- 2009
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23. The cost of everything and the value of nothing: the first corrective steps are to stop ignoring and start measuring the unmet secondary elective healthcare need.
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Bagshaw P, Bagshaw S, Potter JD, Hornblow A, Nicholls MG, and Shaw C
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- Humans, New Zealand, Health Services Needs and Demand economics, Elective Surgical Procedures economics
- Abstract
Competing Interests: Phil Bagshaw is the Chair of Canterbury Charity Hospital Trust.
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- 2024
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24. Assessment of unmet secondary elective healthcare need-itself in need of acute care in Aotearoa New Zealand.
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Bagshaw P, Potter JD, Hornblow A, Hudson B, Toop L, Nicholls MG, Frampton C, Bagshaw S, Gauld R, and Frizelle F
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- Humans, New Zealand, Delivery of Health Care
- Abstract
Competing Interests: Nil.
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- 2023
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25. Funding New Zealand's public healthcare system: time for an honest appraisal and public debate.
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Keene L, Bagshaw P, Nicholls MG, Rosenberg B, Frampton CM, and Powell I
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- Financing, Government, Gross Domestic Product, Health Expenditures trends, Health Services Needs and Demand, Humans, New Zealand, Population Dynamics, Healthcare Financing, Universal Health Insurance economics
- Abstract
Successive New Zealand governments have claimed that the cost of funding the country's public healthcare services is excessive and unsustainable. We contest that these claims are based on a misrepresentation of healthcare spending. Using data from the New Zealand Treasury and the Organisation for Economic Cooperation and Development (OECD), we show how government spending as a whole is low compared with most other OECD countries and is falling as a proportion of GDP. New Zealand has a modest level of health spending overall, but government health spending is also falling as a proportion of GDP. Together, the data indicate the New Zealand Government can afford to spend more on healthcare. We identify compelling reasons why it should do so, including forecast growing health need, signs of increasing unmet need, and the fact that if health needs are not met the costs still have to be borne by the economy. The evidence further suggests it is economically and socially beneficial to meet health needs through a public health system. An honest appraisal and public debate is needed to determine more appropriate levels of healthcare spending.
- Published
- 2016
26. Which heart failure patients profit from natriuretic peptide guided therapy? A meta-analysis from individual patient data of randomized trials.
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Brunner-La Rocca HP, Eurlings L, Richards AM, Januzzi JL, Pfisterer ME, Dahlström U, Pinto YM, Karlström P, Erntell H, Berger R, Persson H, O'Connor CM, Moertl D, Gaggin HK, Frampton CM, Nicholls MG, and Troughton RW
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- Age Factors, Aged, Female, Heart Failure complications, Heart Failure physiopathology, Humans, Male, Randomized Controlled Trials as Topic, Stroke Volume, Heart Failure therapy, Natriuretic Peptide, Brain analysis, Peptide Fragments analysis
- Abstract
Aims: Previous analyses suggest that heart failure (HF) therapy guided by (N-terminal pro-)brain natriuretic peptide (NT-proBNP) might be dependent on left ventricular ejection fraction, age and co-morbidities, but the reasons remain unclear., Methods and Results: To determine interactions between (NT-pro)BNP-guided therapy and HF with reduced [ejection fraction (EF) ≤45%; HF with reduced EF (HFrEF), n = 1731] vs. preserved EF [EF > 45%; HF with preserved EF (HFpEF), n = 301] and co-morbidities (hypertension, renal failure, chronic obstructive pulmonary disease, diabetes, cerebrovascular insult, peripheral vascular disease) on outcome, individual patient data (n = 2137) from eight NT-proBNP guidance trials were analysed using Cox-regression with multiplicative interaction terms. Endpoints were mortality and admission because of HF. Whereas in HFrEF patients (NT-pro)BNP-guided compared with symptom-guided therapy resulted in lower mortality [hazard ratio (HR) = 0.78, 95% confidence interval (CI) 0.62-0.97, P = 0.03] and fewer HF admissions (HR = 0.80, 95% CI 0.67-0.97, P = 0.02), no such effect was seen in HFpEF (mortality: HR = 1.22, 95% CI 0.76-1.96, P = 0.41; HF admissions HR = 1.01, 95% CI 0.67-1.53, P = 0.97; interactions P < 0.02). Age (74 ± 11 years) interacted with treatment strategy allocation independently of EF regarding mortality (P = 0.02), but not HF admission (P = 0.54). The interaction of age and mortality was explained by the interaction of treatment strategy allocation with co-morbidities. In HFpEF, renal failure provided strongest interaction (P < 0.01; increased risk of (NT-pro)BNP-guided therapy if renal failure present), whereas in HFrEF patients, the presence of at least two of the following co-morbidities provided strongest interaction (P < 0.01; (NT-pro)BNP-guided therapy beneficial only if none or one of chronic obstructive pulmonary disease, diabetes, cardiovascular insult, or peripheral vascular disease present). (NT-pro)BNP-guided therapy was harmful in HFpEF patients without hypertension (P = 0.02)., Conclusion: The benefits of therapy guided by (NT-pro)BNP were present in HFrEF only. Co-morbidities seem to influence the response to (NT-pro)BNP-guided therapy and may explain the lower efficacy of this approach in elderly patients., (© 2015 The Authors European Journal of Heart Failure © 2015 European Society of Cardiology.)
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- 2015
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27. The importance of measuring unmet healthcare needs.
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Gauld R, Raymont A, Bagshaw PF, Nicholls MG, and Frampton CM
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- Health Care Reform, Humans, Medically Underserved Area, New Zealand, Delivery of Health Care organization & administration, Health Services Accessibility, Health Services Needs and Demand, Health Services Research
- Abstract
Major restructuring of the health sector has been undertaken in many countries, including New Zealand and England, yet objective assessment of the outcomes has rarely been recorded. In the absence of comprehensive objective data, the success or otherwise of health reforms has been inferred from narrowly-focussed data or anecdotal accounts. A recent example relates to a buoyant King's Fund report on the quest for integrated health and social care in Canterbury, New Zealand which prompted an equally supportive editorial article in the British Medical Journal (BMJ) suggesting it may contain lessons for England's National Health Service. At the same time, a report published in the New Zealand Medical Journal expressed concerns at the level of unmet healthcare needs in Canterbury. Neither report provided objective information about changes over time in the level of unmet healthcare needs in Canterbury. We propose that the performance of healthcare systems should be measured regularly, objectively and comprehensively through documentation of unmet healthcare needs as perceived by representative segments of the population at formal interview. Thereby the success or otherwise of organisational changes to a health system and its adequacy as demographics of the population evolve, even in the absence of major restructuring of the health sector, can be better documented.
- Published
- 2014
28. Endogenous ouabain is not ouabain.
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Lewis LK, Yandle TG, Hilton PJ, Jensen BP, Begg EJ, and Nicholls MG
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- Animals, Humans, Immunoassay, Blood Pressure drug effects, Ouabain blood, Ouabain pharmacology, Sodium-Potassium-Exchanging ATPase antagonists & inhibitors
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- 2014
- Full Text
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29. Effect of B-type natriuretic peptide-guided treatment of chronic heart failure on total mortality and hospitalization: an individual patient meta-analysis.
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Troughton RW, Frampton CM, Brunner-La Rocca HP, Pfisterer M, Eurlings LW, Erntell H, Persson H, O'Connor CM, Moertl D, Karlström P, Dahlström U, Gaggin HK, Januzzi JL, Berger R, Richards AM, Pinto YM, and Nicholls MG
- Subjects
- Aged, Angiotensin Receptor Antagonists therapeutic use, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Biomarkers metabolism, Chronic Disease, Drug Substitution statistics & numerical data, Female, Heart Failure blood, Heart Failure mortality, Hospitalization statistics & numerical data, Humans, Kaplan-Meier Estimate, Male, Randomized Controlled Trials as Topic, Sodium Potassium Chloride Symporter Inhibitors therapeutic use, Treatment Outcome, Ventricular Dysfunction, Left blood, Ventricular Dysfunction, Left mortality, Ventricular Dysfunction, Left therapy, Heart Failure drug therapy, Natriuretic Peptide, Brain metabolism
- Abstract
Aims: Natriuretic peptide-guided (NP-guided) treatment of heart failure has been tested against standard clinically guided care in multiple studies, but findings have been limited by study size. We sought to perform an individual patient data meta-analysis to evaluate the effect of NP-guided treatment of heart failure on all-cause mortality., Methods and Results: Eligible randomized clinical trials were identified from searches of Medline and EMBASE databases and the Cochrane Clinical Trials Register. The primary pre-specified outcome, all-cause mortality was tested using a Cox proportional hazards regression model that included study of origin, age (<75 or ≥75 years), and left ventricular ejection fraction (LVEF, ≤45 or >45%) as covariates. Secondary endpoints included heart failure or cardiovascular hospitalization. Of 11 eligible studies, 9 provided individual patient data and 2 aggregate data. For the primary endpoint individual data from 2000 patients were included, 994 randomized to clinically guided care and 1006 to NP-guided care. All-cause mortality was significantly reduced by NP-guided treatment [hazard ratio = 0.62 (0.45-0.86); P = 0.004] with no heterogeneity between studies or interaction with LVEF. The survival benefit from NP-guided therapy was seen in younger (<75 years) patients [0.62 (0.45-0.85); P = 0.004] but not older (≥75 years) patients [0.98 (0.75-1.27); P = 0.96]. Hospitalization due to heart failure [0.80 (0.67-0.94); P = 0.009] or cardiovascular disease [0.82 (0.67-0.99); P = 0.048] was significantly lower in NP-guided patients with no heterogeneity between studies and no interaction with age or LVEF., Conclusion: Natriuretic peptide-guided treatment of heart failure reduces all-cause mortality in patients aged <75 years and overall reduces heart failure and cardiovascular hospitalization., (© The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.)
- Published
- 2014
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30. Increased plasma norepinephrine levels in previously pre-eclamptic women.
- Author
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Lampinen KH, Rönnback M, Groop PH, Nicholls MG, Yandle TG, and Kaaja RJ
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- Adult, Biomarkers blood, Blood Pressure physiology, Case-Control Studies, Female, Heart Rate physiology, Humans, Hypertension physiopathology, Insulin Resistance physiology, Pre-Eclampsia physiopathology, Pregnancy, Risk Factors, Sympathetic Nervous System physiology, Time Factors, Cardiovascular Diseases epidemiology, Endothelin-1 blood, Hypertension complications, Norepinephrine blood, Postpartum Period, Pre-Eclampsia blood
- Abstract
A history of pre-eclampsia increases the risk of cardiovascular morbidity by mechanisms yet unknown. The aim of the present study was to assess whether plasma norepinephrine (NE) levels are increased 5-6 years after pre-eclamptic pregnancy and to investigate associations with pathophysiological mechanisms of cardiovascular disease: insulin sensitivity, vascular function and arterial pressure. A total of 28 women with previous pre-eclampsia and 20 controls were examined. Blood pressure (BP) and plasma levels of NE and endothelin-1 (ET-1) were measured at rest and after standing for 5 min. Insulin sensitivity was assessed with minimal model analysis and vascular function was assessed using venous occlusion plethysmography and pulse wave analysis. Twenty-four-hour BP measurements were carried out. Women with previous pre-eclampsia had higher levels of NE at rest (P=0.02), which did not associate significantly with insulin sensitivity or overall vasodilatory capacity. The 24-h mean of systolic and diastolic blood pressures (BPs) and heart rate did not differ between the groups (P=0.30, P=0.10 and P=0.46, respectively), and there was no significant association with NE levels. ET-1 levels were similar between the groups, but a positive correlation with systolic (P=0.04) and diastolic (P=0.03) BPs in the upright position was shown in the patient group. Increased levels of plasma NE are sustained in women with previous pre-eclampsia and may contribute to the increased risk for cardiovascular disease in these women.
- Published
- 2014
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31. B-type natriuretic peptide forms within the heart, coronary sinus, and peripheral circulation in humans: evidence for degradation before secretion.
- Author
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Mahagamasekera PG, Ruygrok PN, Palmer SC, Richards AM, Ansell GS, Nicholls MG, Pemberton CJ, Lewis LK, and Yandle TG
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- Heart Failure metabolism, Heart Failure physiopathology, Humans, Natriuretic Peptide, Brain blood, Protein Precursors blood, Protein Precursors metabolism, Regional Blood Flow, Ventricular Function, Left, Coronary Sinus metabolism, Myocardium metabolism, Natriuretic Peptide, Brain metabolism
- Abstract
Background: The B-type natriuretic peptides (BNP and N-terminal pro-BNP) are secreted by the heart and, in the case of BNP, serve to maintain circulatory homeostasis through renal and vascular actions and oppose many effects of the renin-angiotensin system. Recent evidence suggests that in patients with severe heart failure, circulating immunoreactive BNP is made up mainly of metabolites that may have reduced bioactivity. We hypothesized that BNP may be degraded before it even leaves the heart., Methods: Peripheral venous plasma plus atrial and ventricular tissue, obtained from explanted hearts at the time of transplantation, were collected from 3 patients with end-stage heart failure. In a separate study, plasma was collected from the coronary sinus and femoral artery of 3 separate patients undergoing cardiac catheterization. Plasma C18 reverse-phase extracts were separated on reverse-phase HPLC, and the collected fractions were subjected to RIAs with highly specific antisera directed to the amino- and carboxy-terminal ends of BNP(1-32)., Results: ProBNP, BNP(1-32), and 2 major BNP metabolites were present in atrial and ventricular tissue, where BNP(1-32) represented 45% and 70% of total processed BNP, respectively. Neither BNP(1-32) nor the 2 metabolites were detected in peripheral venous plasma. Nor was BNP(1-32) detected in matching coronary sinus and femoral artery plasma from the 3 patients undergoing cardiac catheterization., Conclusions: BNP(1-32) is partly degraded within the hearts of patients with end-stage heart failure, and even in patients with relatively well-preserved left ventricular systolic function, only BNP metabolites enter the systemic circulation.
- Published
- 2014
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32. The Canterbury Charity Hospital: an update (2010-2012) and effects of the earthquakes.
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Bagshaw PF, Maimbo-M'siska M, Nicholls MG, Shaw CG, Allardyce RA, Bagshaw SN, McNabb AL, Johnson SS, Frampton CM, and Stokes BW
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- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Female, Humans, Male, Middle Aged, New Zealand, Referral and Consultation economics, Retrospective Studies, Uncompensated Care statistics & numerical data, Young Adult, Ambulatory Care organization & administration, Charities, Earthquakes, Health Services Accessibility organization & administration, Hospital Volunteers organization & administration, Referral and Consultation statistics & numerical data
- Abstract
Aim: To update activities of the Canterbury Charity Hospital (CCH) and its Trust over the 3 years 2010-2012, during which the devastating Christchurch earthquakes occurred., Methods: Patients' treatments, establishment of new services, expansion of the CCH, staffing and finances were reviewed., Results: Previously established services including general surgery continued as before, some services such as ophthalmology declined, and new services were established including colonoscopy, dentistry and some gynaecological procedures; counselling was provided following the earthquakes. Teaching and research endeavours increased. An adjacent property was purchased and renovated to accommodate the expansion. The Trust became financially self-sustaining in 2010; annual running costs of $340,000/year were maintained but were anticipated to increase soon. Of the money generously donated by the community to the Trust, 82% went directly to patient care. Although not formally recorded, hundreds of appointment request were rejected because of service unavailability or unmet referral criteria., Conclusions: This 3-year review highlights substantial, undocumented unmet healthcare needs in the region, which were exacerbated by the 2010/2011 earthquakes. We contend that the level of unmet healthcare in Canterbury and throughout the country should be regularly documented to inform planning of public healthcare services.
- Published
- 2013
33. Interactions of enhanced urocortin 2 and mineralocorticoid receptor antagonism in experimental heart failure.
- Author
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Rademaker MT, Charles CJ, Nicholls MG, and Richards AM
- Subjects
- Animals, Canrenoic Acid administration & dosage, Cardiac Pacing, Artificial, Drug Interactions, Epinephrine blood, Female, Heart Failure drug therapy, Heart Failure metabolism, Hemodynamics drug effects, Hydrocortisone blood, Mineralocorticoid Receptor Antagonists administration & dosage, Norepinephrine blood, Potassium urine, Renin-Angiotensin System drug effects, Sheep, Sodium urine, Urocortins administration & dosage, Urocortins metabolism, Canrenoic Acid pharmacology, Heart Failure physiopathology, Mineralocorticoid Receptor Antagonists pharmacology, Urocortins pharmacology
- Abstract
Background: Mineralocorticoid receptor antagonists (MRAs) have become established therapy in heart failure (HF). Urocortin 2 (Ucn2) is a novel peptide with potential in the treatment of this disease. The present study investigated the interactions of acute administration of Ucn2 and an MRA in experimental HF., Methods and Results: Ucn2 and an MRA (canrenoic acid [CA]) were infused for 4 hours, both singly and together, in 8 sheeps with pacing-induced HF. Ucn2, when administered as an adjunct to CA, further improved hemodynamic indices relative to that achieved by CA alone, producing additional increases in cardiac output and decreases in left atrial pressure and peripheral resistance but without eliciting a supplementary reduction in arterial pressure. Ucn2 cotreatment reversed CA-induced rises in circulating aldosterone levels, and also significantly reduced plasma renin activity, angiotensin II, and vasopressin concentrations. Although both CA and Ucn2 infusion produced a diuresis and natriuresis, responses with Ucn2 and Ucn+CA were 2- to 3-fold greater than that elicited by separate CA. Ucn2 cotherapy additionally increased urine potassium and creatinine excretion. In contrast to the rise in plasma potassium induced by CA, Ucn2 cotreatment reduced potassium concentrations., Conclusions: Ucn2 cotreatment with an MRA in HF further improved hemodynamics relative to that achieved by CA alone, while also reducing plasma renin activity, angiotensin II, aldosterone and vasopressin levels, and enhancing renal function. Importantly, Ucn2 prevented CA-induced rises in plasma potassium. These data demonstrate a favorable profile of effects with short-term adjunct Ucn2 therapy and an MRA in HF.
- Published
- 2013
- Full Text
- View/download PDF
34. ANP and BNP responses to dehydration in the one-humped camel and effects of blocking the renin-angiotensin system.
- Author
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Adem A, Al Haj M, Benedict S, Yasin J, Nagelkerke N, Nyberg F, Yandle TG, Frampton CM, Lewis LK, Nicholls MG, and Kazzam E
- Subjects
- Angiotensin II Type 1 Receptor Blockers pharmacology, Animals, Atrial Natriuretic Factor blood, Dehydration drug therapy, Losartan pharmacology, Male, Myocardium metabolism, Natriuretic Peptide, Brain blood, Renin-Angiotensin System drug effects, Atrial Natriuretic Factor metabolism, Camelus physiology, Dehydration metabolism, Natriuretic Peptide, Brain metabolism, Renin-Angiotensin System physiology
- Abstract
The objectives of this study were to investigate and compare the responses of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) in the circulation of hydrated, dehydrated, and dehydrated losartan - treated camels; and to document the cardiac storage form of B-type natriuretic peptide in the camel heart. Eighteen male camels were used in the study: control or hydrated camels (n = 6), dehydrated camels (n = 6) and dehydrated losartan-treated camels (n = 6) which were dehydrated and received the angiotensin II (Ang II) AT-1 receptor blocker, losartan, at a dose of 5 mg/kg body weight intravenously for 20 days. Control animals were supplied with feed and water ad-libitum while both dehydrated and dehydrated-losartan treated groups were supplied with feed ad-libitum but no water for 20 days. Compared with time-matched controls, dehydrated camels exhibited a significant decrease in plasma levels of both ANP and BNP. Losartan-treated camels also exhibited a significant decline in ANP and BNP levels across 20 days of dehydration but the changes were not different from those seen with dehydration alone. Size exclusion high performance liquid chromatography of extracts of camel heart indicated that proB-type natriuretic peptide is the storage form of the peptide. We conclude first, that dehydration in the camel induces vigorous decrements in circulating levels of ANP and BNP; second, blockade of the renin-angiotensin system has little or no modulatory effect on the ANP and BNP responses to dehydration; third, proB-type natriuretic peptide is the storage form of this hormone in the heart of the one-humped camel.
- Published
- 2013
- Full Text
- View/download PDF
35. Hemodynamic, hormonal, and renal effects of (pro)renin receptor blockade in experimental heart failure.
- Author
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Rademaker MT, Yandle TG, Ellmers LJ, Charles CJ, Nicholls MG, and Richards AM
- Subjects
- Animals, Arterial Pressure drug effects, Atrial Function, Left drug effects, Atrial Pressure drug effects, Biomarkers blood, Cardiac Output drug effects, Cardiac Pacing, Artificial, Disease Models, Animal, Dose-Response Relationship, Drug, Female, Heart Failure metabolism, Heart Failure physiopathology, Kidney metabolism, Kidney physiopathology, Myocardial Contraction drug effects, Natriuresis drug effects, Receptors, Cell Surface metabolism, Renin-Angiotensin System drug effects, Sheep, Time Factors, Vascular Resistance drug effects, Prorenin Receptor, Cardiovascular Agents pharmacology, Heart Failure drug therapy, Hemodynamics drug effects, Hormones blood, Kidney drug effects, Oligopeptides pharmacology, Receptors, Cell Surface antagonists & inhibitors
- Abstract
Background: The (pro)renin receptor (P)RR is implicated in blood pressure regulation and the pathophysiology of heart failure (HF). The effects of (P)RR blockade in HF have not been previously investigated., Methods and Results: Eight sheep received on 2 separate days a vehicle control and incremental intravenous boluses of a (P)RR antagonist, ovine handle region peptide (HRP) (1, 5, and 25 mg at 90-minute intervals), both before (normal) and after induction of HF by rapid left ventricular pacing. In normal sheep, HRP reduced heart rate (P<0.001) and hematocrit (P=0.019) compared with time-matched control data, without significantly affecting any other hemodynamic, hormonal, or renal variables. In sheep with HF, HRP treatment induced progressive falls in mean arterial pressure (P<0.001) in association with decreases in left atrial pressure (P<0.001), peripheral resistance (P=0.014), and hematocrit (P<0.001). Cardiac contractility tended to decline (P=0.096), whereas cardiac output was unaltered. HRP administration produced a dose-dependent decrease in plasma renin activity (P=0.004), with similar trends observed for plasma angiotensin II and aldosterone (P=0.093 and P=0.088, respectively). Circulating natriuretic peptides, endothelin-1, and catecholamine levels were unchanged. HRP also induced a reduction in plasma sodium concentrations relative to control (P=0.024), a natriuresis (P=0.046), and a tendency for creatinine excretion and clearance to improve., Conclusions: (P)RR antagonism in experimental HF resulted in cardiovascular and renal benefits in association with inhibition of the renin-angiotensin-aldosterone system. These findings suggest that (P)RR contributes to pressure/volume regulation in HF and identifies the receptor as a potential therapeutic target in this disease.
- Published
- 2012
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36. Prediction of cardiac rhythm 1 year following cardioversion for atrial fibrillation.
- Author
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Hamid AK, Richards AM, Crozier IG, Lainchbury JG, Melton I, Bridgman PG, Palmer SC, Frampton CM, and Nicholls MG
- Subjects
- Aged, Amiodarone therapeutic use, Anti-Arrhythmia Agents therapeutic use, Anticoagulants therapeutic use, Atrial Fibrillation mortality, Atrial Fibrillation physiopathology, Atrial Flutter mortality, Atrial Flutter physiopathology, Atrial Flutter therapy, Chi-Square Distribution, Electrocardiography, Female, Humans, Logistic Models, Male, Middle Aged, Predictive Value of Tests, Statistics, Nonparametric, Treatment Outcome, Atrial Fibrillation therapy, Electric Countershock methods
- Abstract
Background: There is little recent information regarding outcome and its determinants following cardioversion (CV) for atrial fibrillation (AF) or flutter. This study aims to help improve prediction of cardiac rhythm outcome following CV for AF., Methods: Cardiac rhythm at 6 weeks and 12 months was documented following elective (EC; n=496) or immediate (IC; n=52) cardioversion for AF or atrial flutter in a single referral centre., Results: 65 and 58% of IC patients remained in sinus rhythm (SR) 6 weeks and 1 year after CV (respectively) compared with 43% and 30% in EC patients (P<0.001). Independent positive predictors of SR 6 weeks after cardioversion included amiodarone therapy (OR 2.04 [1.28-3.33], P<0.01) and atrial flutter (OR 1.85 [1.09-3.13], P<0.05). Negative predictors included the need for >1 shock to achieve SR (OR 1.61 [1.12-2.37], P=0.011) and arrhythmia duration, (OR 0.96 [0.95-0.97], P<0.001). At 1 year, amiodarone, duration of arrhythmia and the need for >1 shock remained independent predictors of rhythm., Conclusions: The number of shocks required to achieve SR is a newly demonstrated independent predictor of rhythm outcome after elective CV.
- Published
- 2011
37. A call for screening for benign neutropenia in Arab populations.
- Author
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Denic S and Nicholls MG
- Subjects
- Adolescent, Adult, Aged, Child, Humans, Middle Aged, Young Adult, Arabs, Neutropenia diagnosis
- Published
- 2011
38. Prolonged urocortin 2 administration in experimental heart failure: sustained hemodynamic, endocrine, and renal effects.
- Author
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Rademaker MT, Charles CJ, Ellmers LJ, Lewis LK, Nicholls MG, and Richards AM
- Subjects
- Aldosterone blood, Animals, Blood Pressure drug effects, Cardiac Output drug effects, Creatinine urine, Endocrine System drug effects, Endocrine System physiopathology, Endothelin-1 blood, Female, Heart drug effects, Heart physiopathology, Heart Failure blood, Heart Failure urine, Infusions, Intravenous, Kidney drug effects, Kidney physiopathology, Mice, Oligopeptides blood, Renin blood, Sheep, Sodium urine, Time Factors, Urocortins administration & dosage, Vasopressins blood, Heart Failure physiopathology, Hemodynamics drug effects, Urocortins pharmacology, Vascular Resistance drug effects
- Abstract
Although acute administration of urocortin 2 has beneficial actions in heart failure, the integrated hemodynamic, hormonal, and renal effects of sustained urocortin 2 treatment in this disease have not been investigated. In the current study, we administered a 4-day infusion of a vehicle control (0.9% saline; n=6) or urocortin 2 (0.75 μg/kg per hour; n=6) to sheep with pacing-induced heart failure. Compared with time-matched controls, infusion of urocortin 2 produced rapid (30-minute) and persistent (4-day) improvements in cardiac contractility (day 4: control 905±73 versus urocortin 2 1424±158 mm Hg/s; P<0.001) and output (2.6±0.1 versus 3.8±0.3 L/min; P<0.001), together with reductions in left atrial pressure (28±1 versus 12±1 mm Hg; P<0.001) and peripheral resistance (30±2 versus 20±2 mm Hg/L per min; P<0.001). In contrast, urocortin 2-induced falls in mean arterial pressure were not established until the second day (day 4: 74±2 versus 72±2 mm Hg; P<0.05). Prolonged urocortin 2 administration was associated with sustained (days 0 to 4) declines in plasma renin activity (day 4: 1.33±0.27 versus 0.73±0.20 nmol/L per hour; P<0.001), aldosterone (970±383 versus 396±96 pmol/L; P<0.05), vasopressin (2.4±0.8 versus 1.3±0.1 pmol/L; P<0.05), endothelin 1 (7.2±0.7 versus 4.5±0.4 pmol/L; P<0.01), and atrial (269±27 versus 150±19 pmol/L; P<0.001) and B-type (65±9 versus 29±6 pmol/L; P<0.001) natriuretic peptides, as well as an acute transient rise in plasma cortisol (day 1: P<0.001). Chronic urocortin 2 also persistently augmented urinary sodium (day 4: 4-fold increase; P<0.001) and creatinine (1.4-fold; P<0.001) excretion and creatinine clearance (1.5-fold; P<0.01) compared with control. Food consumption was temporarily suppressed (P<0.05). In conclusion, 4-day urocortin 2 administration induces sustained improvements in hemodynamics and renal function, in association with inhibition of multiple vasoconstrictor/volume-retaining systems. These findings support the therapeutic potential for urocortin 2 in heart failure.
- Published
- 2011
- Full Text
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39. Patients "falling through the cracks". The Canterbury Charity Hospital: initial progress report.
- Author
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Bagshaw PF, Allardyce RA, Bagshaw SN, Stokes BW, Shaw CS, Proffit LJ, Nicholls MG, Begg EJ, and Frampton CM
- Subjects
- Ambulatory Care organization & administration, Ambulatory Surgical Procedures classification, Ambulatory Surgical Procedures statistics & numerical data, Charities, Female, Hospital Volunteers classification, Humans, Male, Middle Aged, Outpatient Clinics, Hospital organization & administration, Health Services Accessibility organization & administration, Hospital Volunteers organization & administration, Hospitals, Community organization & administration, Uncompensated Care statistics & numerical data
- Abstract
Aim: To present the early experience of establishing a community-funded and volunteer-staffed hospital in Christchurch, New Zealand. This was to provide free selected elective healthcare services to patients in the Canterbury region who were otherwise unable to access treatment in the public health system or afford private healthcare., Methods: Data were reviewed relating to the establishment, financing, staffing and running of the Canterbury Charity Hospital. Details were provided of patients referred by their general practitioners who were seen and treated during the first two and a half years of function., Results: Canterbury Charity Hospital Trust, established in 2004, completed the purchase of a residential villa in 2005 and converted it into the Canterbury Charity Hospital, which performed its first operations in 2007. By the end of December 2009, 115 volunteer health professionals and 79 non-medical volunteers had worked at the Hospital, provided a total of 966 outpatient clinic appointments, of which 609 were initial assessments, and performed 610 surgical procedures. Funding of $NZ4.3 million (end of last financial year) came from fundraising events, donations, grants and interest from investments. There has been no government funding., Conclusions: There is a substantial unmet need for elective healthcare in Canterbury, and this has, in part, been addressed by the recently established Canterbury Charity Hospital. The overwhelming community response we have experienced in Canterbury raises the question of whether the current public health system needs attention to be re-focused on unmet need. We contend that unless this occurs it might be necessary to establish charity-type hospitals elsewhere throughout the country.
- Published
- 2010
40. Urocortin 2 inhibits furosemide-induced activation of renin and enhances renal function and diuretic responsiveness in experimental heart failure.
- Author
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Rademaker MT, Charles CJ, Nicholls MG, and Richards AM
- Subjects
- Aldosterone blood, Animals, Biomarkers blood, Cardiac Pacing, Artificial, Creatinine blood, Disease Models, Animal, Drug Administration Schedule, Drug Therapy, Combination, Female, Heart Failure etiology, Heart Failure metabolism, Heart Failure physiopathology, Hemodynamics drug effects, Infusions, Intra-Arterial, Kidney metabolism, Kidney physiopathology, Mice, Natriuresis drug effects, Potassium blood, Sheep, Time Factors, Urination drug effects, Vasopressins blood, Cardiovascular Agents administration & dosage, Corticotropin-Releasing Hormone administration & dosage, Diuretics administration & dosage, Furosemide administration & dosage, Heart Failure drug therapy, Kidney drug effects, Renin blood, Renin-Angiotensin System drug effects, Urocortins administration & dosage
- Abstract
Background: Urocortin 2 (Ucn2), a novel peptide with therapeutic potential in heart failure, and diuretics have opposing effects on renal function and the renin-angiotensin-aldosterone system. Because any prospective new treatment is likely to be used in conjunction with standard diuretic therapy, it is necessary to investigate the combined effects of these agents., Methods and Results: Ucn2 and furosemide were administered for 3 hours, both singly and combined, in 7 sheep with pacing-induced heart failure. Compared with time-matched controls, separate Ucn2 and furosemide administration significantly increased urine output (furosemide>Ucn2), urine sodium (furosemide>Ucn2), potassium (furosemide>Ucn2), and creatinine excretion (Ucn2>furosemide) and creatinine clearance (Ucn2>furosemide). Compared with furosemide treatment alone, Ucn2+furosemide produced a further diuresis (P<0.05), natriuresis (P<0.05), and a sustained increase in creatinine excretion (P<0.05) and clearance (P<0.05), without additional potassium elimination. All active treatments reduced mean arterial pressure (Ucn2+furosemide=furosemide>Ucn2), left atrial pressure (Ucn2+furosemide>Ucn2>furosemide), and peripheral resistance (Ucn2+furosemide=Ucn2>furosemide), whereas only Ucn2, singly and in combination with furosemide, increased cardiac output and dP/dt(max). In contrast to the increase in plasma renin activity elicited by furosemide alone, Ucn2 and Ucn2+furosemide markedly reduced plasma renin activity. All active treatments decreased plasma aldosterone (Ucn2+furosemide=Ucn2>furosemide), whereas only Ucn2 and Ucn2+furosemide reduced vasopressin and natriuretic peptide concentrations., Conclusions: Ucn2 cotreatment with furosemide enhanced hemodynamic and renal function and diuretic responsiveness (without additional potassium depletion) in experimental heart failure. Furthermore, Ucn2 reversed furosemide-induced increases in plasma renin activity and induced greater decreases in plasma aldosterone and vasopressin. These data indicate that adjunct Ucn2 therapy with diuretics in heart failure is beneficial.
- Published
- 2009
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41. Regional clearance of amino-terminal pro-brain natriuretic peptide from human plasma.
- Author
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Palmer SC, Yandle TG, Nicholls MG, Frampton CM, and Richards AM
- Subjects
- Female, Glomerular Filtration Rate, Head, Humans, Liver metabolism, Male, Middle Aged, Multivariate Analysis, Musculoskeletal System metabolism, Natriuretic Peptide, Brain metabolism, Neck, Peptide Fragments metabolism, Prospective Studies, Regression Analysis, Statistics as Topic, Stroke Volume, Ventricular Function, Left, Kidney metabolism, Natriuretic Peptide, Brain blood, Peptide Fragments blood
- Abstract
Aims: Mechanisms for clearance of circulating amino-terminal pro-brain natriuretic peptide (NT-proBNP) remain poorly understood and are relevant to the clinical utility of NT-proBNP as a diagnostic and prognostic biomarker in cardiovascular disorders. We sought to determine site(s) of production and clearance of plasma NT-proBNP in the human circulation., Methods and Results: In 120 subjects undergoing clinically indicated cardiac catheterization, blood samples were collected from arterial and multiple venous sites to measure transorgan gradients of plasma NT-proBNP. Clearance of plasma NT-proBNP occurred across kidney, liver, musculoskeletal, and head and neck tissues. Proportions of calculated total body NT-proBNP clearance were 55-65% across the kidney, 20-25% across the liver, 10-15% across musculoskeletal tissue, and 5-10% across the head and neck. Renal fractional extraction of NT-proBNP was unrelated to estimated glomerular filtration rate. Transorgan gradients, reflecting both renal and extra-renal NT-proBNP degradation, were correlated across multiple clearance sites within an individual., Conclusion: Plasma NT-proBNP is cleared by multiple tissues in the human circulation with approximately 55-65% of total clearance occurring in renal tissue. These data provide the first evidence for extra-glomerular clearance of NT-proBNP and suggest a common multisite clearance mechanism subject to generalized regulation. Renal NT-proBNP extraction was sustained in the face of even moderate levels of kidney dysfunction.
- Published
- 2009
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42. Renal and cardiac function for long-term (10 year) risk stratification after myocardial infarction.
- Author
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Palmer SC, Yandle TG, Frampton CM, Troughton RW, Nicholls MG, and Richards AM
- Subjects
- Aged, Cohort Studies, Female, Glomerular Filtration Rate physiology, Heart Failure blood, Heart Failure mortality, Hospitalization, Humans, Kidney Failure, Chronic blood, Kidney Failure, Chronic mortality, Male, Middle Aged, Myocardial Infarction blood, Myocardial Infarction mortality, Natriuretic Peptide, Brain blood, Peptide Fragments blood, Prognosis, Risk Assessment, Stroke Volume physiology, Time Factors, Ventricular Dysfunction, Left blood, Ventricular Dysfunction, Left mortality, Heart Failure physiopathology, Kidney Failure, Chronic physiopathology, Myocardial Infarction physiopathology, Ventricular Dysfunction, Left physiopathology
- Abstract
Aims To determine whether combined renal and cardiac function after acute myocardial infarction (MI) predicts 10 year mortality and heart failure (HF). Methods and results Estimated glomerular filtration rate (eGFR), plasma amino terminal pro-brain natriuretic peptide (NT-proBNP), and radionuclide ventriculography were obtained in 1063 patients with MI between 24-96 h of symptom onset. Mortality and HF were documented over follow-up of 9.3 years. Estimated GFR, NT-proBNP, and left ventricular ejection fraction (LVEF) each independently predicted 10 year mortality. Reduced eGFR (below 60 mL/min/1.73 m(2)) combined with increased NT-proBNP (above 1000 pg/mL) was associated with higher mortality rate compared with preserved eGFR together with lower NT-proBNP (60 vs. 14%, P < 0.001). Similar results for mortality were identified for eGFR combined with LVEF (dichotomized about 50%) (58 vs. 17%, P < 0.001). Corresponding analysis combining eGFR and NT-proBNP to predict HF yielded rates of 34 and 7% for high- and low-risk groups, respectively (P < 0.001). Similar risk stratification for HF was observed when combining eGFR with LVEF (35 vs. 7%, P < 0.001). Conclusion Ten year rates of mortality and HF are 5-10 times higher when lower eGFR is present together with increased NT-proBNP or depressed LVEF.
- Published
- 2009
- Full Text
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43. Serum 25-hydroxyvitamin D is not related to cardiac natriuretic peptide in nulliparous and lactating women.
- Author
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Saadi HF, Nicholls MG, Frampton CM, Benedict S, and Yasin J
- Abstract
Background: Vitamin D deficiency is associated with heightened risk of cardiovascular disease. Potential mechanisms include involvement of vitamin D in regulation of renin-angiotensin system and manufacture and secretion of cardiac natriuretic peptides. Our aim was to document relationships between 25 hydroxyvitamin [25(OH)D] and N-terminal pro B-type natriuretic peptide (NT-proBNP) and plasma renin activity (PRA) levels and to document the effect of vitamin D administration on NT-proBNP and PRA levels in vitamin D deficient subjects., Methods: Serum 25(OH)D, parathyroid hormone (PTH), plasma or serum NT-proBNP and PRA levels were measured at baseline in nulliparous and lactating women and after 2 months of oral vitamin D2 (2,000 IU/day or 60,000 IU/month) supplementation to lactating women., Results: Baseline levels of 25(OH)D were low (<50 nmol/L) in most women whereas PRA and NT-proBNP levels were within the normal range. There were no significant correlations between baseline 25(OH)D or PTH with NT-proBNP and PRA. Vitamin D administration over a 2-month period in lactating women was associated with a decline in NT-proBNP (by 9.1 +/- 2.0 pmol/L; p < 0.001) and PRA (by 0.32 +/- 0.17 nmol/L/hr; p = 0.064). However, there were no significant correlations between the changes from baseline in 25(OH)D and either NT-proBNP (r = -0.04, p = 0.8) or PRA (r = -0.04, p = 0.8)., Conclusion: We found no significant correlations between 25(OH)D or PTH with NT-proBNP and PRA in vitamin D deficient women. Further information is required to clarify the effects of vitamin D administration on cardiac structure and function.
- Published
- 2009
- Full Text
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44. Plasma aldosterone levels during hospitalization are predictive of survival post-myocardial infarction.
- Author
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Palmer BR, Pilbrow AP, Frampton CM, Yandle TG, Skelton L, Nicholls MG, and Richards AM
- Subjects
- Atrial Natriuretic Factor blood, Biomarkers blood, Female, Follow-Up Studies, Hospital Mortality, Humans, Male, Middle Aged, Myocardial Infarction drug therapy, Myocardial Infarction mortality, Natriuretic Peptide, Brain blood, Peptide Fragments blood, Predictive Value of Tests, Regression Analysis, Survival Analysis, Aldosterone blood, Myocardial Infarction blood
- Abstract
Aims: Plasma aldosterone levels have been shown to be associated with adverse clinical outcomes after ST-elevation myocardial infarction (STEMI). We investigated whether aldosterone levels in patients presenting with STEMI or non-STEMI, are predictive of mortality during prolonged follow-up., Methods and Results: Aldosterone levels were assayed in plasma taken from 583 patients within 24-96 h following acute myocardial infarction (MI). The median plasma aldosterone level was 108 pmol/L and all values were below the upper limit of the normal range (800 pmol/L) except for five patients (0.9%). Aldosterone tertile was significantly associated with increasing plasma levels of NTproBNP (N-terminal pro-B-type natriuretic peptide), BNP (B-type natriuretic peptide), epinephrine, and endothelin-1 (P
or=25.3% mortality, P >or= 0.026)., Conclusion: Plasma aldosterone levels post-MI are independent predictors of survival and hospitalization for heart failure over a 5-year-follow-up period. - Published
- 2008
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45. Hemodynamic, hormonal, and renal actions of adrenomedullin 2 in experimental heart failure.
- Author
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Rademaker MT, Charles CJ, Nicholls MG, and Richards AM
- Subjects
- Animals, Creatinine metabolism, Disease Models, Animal, Dose-Response Relationship, Drug, Female, Follow-Up Studies, Heart Failure physiopathology, Infusions, Intravenous, Peptide Hormones administration & dosage, Sheep, Treatment Outcome, Vascular Resistance drug effects, Aldosterone blood, Glomerular Filtration Rate drug effects, Heart Failure drug therapy, Hemodynamics drug effects, Natriuretic Peptides blood, Peptide Hormones therapeutic use, Renin blood
- Abstract
Background: Adrenomedullin 2 (AM2) is a novel member of the calcitonin gene-related peptide family that is thought to play a regulatory role in circulatory homeostasis under normal physiological conditions. The effects of AM2 in heart failure have not been investigated previously., Methods and Results: Two incremental doses of human AM2 (10 and 100 ng[kg.min] for 90 minutes each) were given by intravenous infusion to 8 sheep with pacing-induced heart failure. Compared with time-matched control infusions, AM2 produced dose-dependent increases in left ventricular dP/dt(max) (control 1168+/-138 mm Hg/s versus AM2 high-dose 1402+/-130 mm Hg/s; P<0.01) and cardiac output (2.09+/-0.66 L/min versus 3.81+/-0.30 L/min; P<0.001) and reductions in calculated total peripheral resistance (40+/-6 mm Hg(L.min) versus 21+/-4 mm Hg(L.min); P<0.001), mean arterial pressure (74.4+/-2.4 mm Hg versus 66.2+/-2.5 mm Hg; P<0.001), and left atrial pressure (23.3+/-1.0 mm Hg versus 18.8+/-1.3 mm Hg; P<0.001). AM2 administration also induced significant elevations in plasma cAMP (P<0.01) in association with rises in atrial (P<0.05) and brain (P<0.01) natriuretic peptides and plasma renin activity (P<0.01). Despite the increase in renin activity, plasma aldosterone levels were not significantly altered, whereas the aldosterone/plasma renin activity ratio was reduced (P=0.08). Plasma vasopressin, endothelin-1, and catecholamines levels were also unchanged by AM2. Renal effects of AM2 included increased excretion of sodium (P<0.05), cAMP (P<0.01), and creatinine (P<0.05), with augmented creatinine clearance (P<0.05), and a trend for urine output to rise (P=0.068)., Conclusions: These results indicate that AM2 administration has favorable effects on cardiovascular, endocrine, and renal indexes in heart failure and identify the peptide as a potential therapeutic target in this disease.
- Published
- 2008
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46. Plasma N terminal pro-brain natriuretic peptide levels and its determinants in a multi-ethnic population.
- Author
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Abdulle AM, Nagelkerke NJ, Adem A, Abouchacra S, Pathan JY, Al-Rukhaimi M, Suleiman MN, Mathew MC, Nicholls MG, and Obineche EN
- Subjects
- Adult, Exercise, Female, Humans, Hypertension ethnology, Male, Middle Aged, United Arab Emirates ethnology, Hypertension blood, Natriuretic Peptide, Brain blood, Peptide Fragments blood
- Abstract
This study documents the determinants and plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) among hypertensive and normotensive subjects in a multi-ethnic population in the United Arab Emirates (UAE). We obtained demographic, anthropometric and clinical data, together with fasting NT-proBNP and biochemical indices from 128 hypertensive patients and 138 normotensive subjects matched for age, gender and ethnicity. Plasma NT-proBNP levels were significantly (P<0.001), and several-fold higher among hypertensives (median 5.92, inter quartile range (IQR): 1.79-18.48 pmol/l) than normotensives (median 1.78, IQR: 0.59-4.32 pmol/l) in the total study population, and the same was true for the ethnic groups separately. Similarly, plasma levels of glucose, blood urea nitrogen (BUN) and creatinine, but not insulin, were significantly (P<0.05) higher among hypertensives than normotensives. For all subjects combined, log NT-proBNP correlated positively and significantly with age (P<0.01), log glucose (P<0.05), systolic blood pressure (SBP, P<0.001), log BUN (P<0.001) and log creatinine (P<0.001). Multivariate regression analysis showed that NT-proBNP levels were independently and positively correlated with SBP, age, gender, log BUN, Emirati and South East Asian ethnic groups and inversely associated with current exercise. In conclusion, we found circulating levels of NT-proBNP to be significantly increased in hypertensive versus normotensive subjects in the UAE and independently related to SBP, age, gender, indices of renal function and possibly exercise. Our results further suggest a possible modulating effect of ethnicity on NT-proBNP levels.
- Published
- 2007
- Full Text
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47. Disease monitoring of patients with chronic heart failure.
- Author
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Nicholls MG and Richards AM
- Subjects
- Chronic Disease, Disease-Free Survival, Heart Failure complications, Heart Failure diagnosis, Humans, Medical History Taking methods, Natriuretic Peptide, Brain metabolism, Patient Education as Topic, Physical Examination methods, Prognosis, Referral and Consultation, Heart Failure therapy
- Published
- 2007
- Full Text
- View/download PDF
48. Genetic benefits of consanguinity through selection of genotypes protective against malaria.
- Author
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Denic S and Nicholls MG
- Subjects
- Alleles, Global Health, Glucosephosphate Dehydrogenase, Humans, Inbreeding, Malaria epidemiology, Malaria prevention & control, Mutation, Prevalence, Risk Factors, alpha-Thalassemia, beta-Thalassemia, Consanguinity, Genotype, Malaria genetics
- Abstract
Consanguineous marriages are usually socially driven and can be genetically harmful. The detrimental effects of inbreeding are the consequence of homozygosity of harmful genes. On the other hand, beneficial effects of inbreeding, theoretically, could be expected in those who are homozygous for protective recessive and codominant genes. Here, we argue that the most common monogenetic conditions in humans, namely, alpha-thalassemia, glucose-6-phosphate dehydrogenase (G6PD) deficiency, hemoglobin C, and Duffy antigen negative red blood cells, which have evolved under pressure from malaria, had their survival and selection enhanced by consanguineous marriages in malaria-infested regions of the world. This hypothesis is supported by several observations. First, the presence of two mutations in homozygotes involving the listed conditions (except G6PD deficiency) imparts better protection against malaria than the presence of one or no mutation (heterozygous or normal genotypes, respectively); consanguinity increases the number of homozygotes, especially at low allele frequency. For G6PD deficiency, inbreeding could increase the allele frequency of the G6PD-deficient allele. Second, there is overlap between, on the one hand, the geographic distributions of malaria, thalassemias, and other red blood cell conditions that protect against malaria and, on the other hand, consanguineous marriages. Third, the distribution of different intensities of malaria infestation is matched with the frequency of human inbreeding. These observations, taken together, offer strong support to the hypothesis that the culture of consanguineous marriages and the genetics of protection against malaria have co-evolved by fostering survival against malaria through better retention of protective genes in the extended family.
- Published
- 2007
- Full Text
- View/download PDF
49. Alendronate prevents bone loss in patients with acute spinal cord injury: a randomized, double-blind, placebo-controlled study.
- Author
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Gilchrist NL, Frampton CM, Acland RH, Nicholls MG, March RL, Maguire P, Heard A, Reilly P, and Marshall K
- Subjects
- Acute Disease, Administration, Oral, Adolescent, Adult, Alendronate administration & dosage, Body Height, Body Mass Index, Bone Density Conservation Agents therapeutic use, Dietary Supplements, Double-Blind Method, Female, Humans, Male, Middle Aged, Patient Compliance, Placebos, Spinal Cord Injuries physiopathology, Treatment Outcome, Vitamin D administration & dosage, Walking, Wheelchairs, Alendronate therapeutic use, Bone Density drug effects, Spinal Cord Injuries drug therapy
- Abstract
Context: Patients who sustain an acute spinal cord injury (SCI) experience rapid dramatic reductions in bone mineral density (BMD), especially marked in sublesional areas and sometimes leading to hypercalcemia and hypercalciuria, as well as increased fracture risk., Objective: In this prospective, double-blind, randomized, placebo-controlled study, we evaluated the hypothesis that oral alendronate administration would preserve BMD when administered soon after acute SCI., Patients and Intervention: Thirty-one patients with acute SCI were randomly allocated to receive oral alendronate 70 mg/wk or placebo, within 10 d of acute SCI, for 12 months., Main Outcome Measurements: At entry and at 3, 6, 12, and 18 months, total body bone density, lumbar and hip BMD, ultrasound of the calcaneus, 24-h urinary calcium, and serum C-telopeptide (betaCTX) were measured., Results: At study entry, patients in the two groups were well matched for age, gender, severity of neurological deficit, BMD, urinary calcium, and betaCTX. BMD indices declined steadily in the placebo group, and this effect was attenuated significantly by alendronate. After 12 months, there was a 5.3% difference (P<0.001) in total body BMD and a 17.6% difference (P<0.001) in the total hip BMD between the two groups. Alendronate compared with placebo induced significant (P<0.001) reductions in urinary calcium excretion and serum betaCTX. No treatment-related side effects were noted., Conclusions: We conclude that alendronate therapy, 70 mg/wk, initiated soon after acute SCI, prevents bone loss and is not associated with side effects.
- Published
- 2007
- Full Text
- View/download PDF
50. Hypothesis: Correction of low vitamin D status among Arab women will prevent heart failure and improve cardiac function in established heart failure.
- Author
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Saadi HF, Kazzam E, Ghurbana BA, and Nicholls MG
- Subjects
- Dietary Supplements, Female, Heart Failure ethnology, Humans, Nutritional Status, United Arab Emirates epidemiology, Vitamin D Deficiency ethnology, Women's Health, Arabs statistics & numerical data, Heart Failure etiology, Heart Failure prevention & control, Vitamin D administration & dosage, Vitamin D Deficiency complications, Vitamin D Deficiency epidemiology
- Abstract
Vitamin D deficiency is common in Arab countries particularly among women. This is the result of a low dietary intake of the vitamin, limited exposure to sunlight (a paradox in view of the high sunshine figures), skin colour, obesity and high parity. Apart from its adverse effects on bone in women and their offspring, vitamin D deficiency has the potential to cause or exacerbate heart failure through a number of mechanisms including activation of the renin-angiotensin system and increased arterial pressure. Accordingly, we propose that ensuring adequate vitamin D levels in Arab women will have a much greater impact on health than just the prevention of bone disease. In particular, we suggest that prevention and correction of vitamin D deficiency will reduce the incidence of heart failure and, for Arab women with established heart failure and vitamin D deficiency, improve cardiac function.
- Published
- 2006
- Full Text
- View/download PDF
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