RESUMEN
In this paper, I take Capital in the Twenty-First Century by Thomas Piketty as the starting point for a set of twelve policy proposals that could bring about a genuine shift in the distribution of income towards less inequality. In designing the set of proposals, I draw on the experience of reducing inequality in postwar Europe and on an analysis as to how the economic circumstances are now different in the twenty-first century, highlighting the role of technical change and the rise in capital emphasized by Piketty. The proposed measures span many fields of policy, and are not confined to fiscal redistribution, encompassing science policy, competition policy, public employment, a guaranteed return on small savings, a capital endowment, as well as more progressive taxation of income and wealth transfers, and a participation income. Inequality is embedded in our social structure, and the search for a significant reduction requires us to examine all aspects of our society. I focus on inequality within countries, and what can be achieved by national governments, with the UK specifically in mind. The primary audience is those concerned with policy-making in national governments, but implementation should not be seen purely in these terms. There are different levels of government, and certain proposals, particularly those concerned with taxation, may only be feasible if pursued by a group of countries in collaboration. The last of the twelve proposals - for a basic income for children - is specifically directed at the European Union. Finally, actions by individuals as consumers, as workers, or as employers, can all contribute to reducing inequality.
Asunto(s)
Política Pública , Sociología/economía , Humanos , Impuesto a la Renta/economía , Literatura , Modelos Económicos , Política , Pobreza , Factores Socioeconómicos , Reino UnidoRESUMEN
An association exists between hyperaldosteronism, hypertension and impaired insulin action. Eplerenone is a selective mineralocorticoid receptor antagonist; however, little is known about its effects on insulin action. The aim of this study was to determine the effect of eplerenone on insulin action in hypertensive adults, using the hyperinsulinaemic euglycaemic clamp. A randomised, controlled, double-blind, crossover design was employed. After a 6-week washout period, hypertensive, non-diabetic patients were treated with either eplerenone 25 mg twice daily or doxazosin 2 mg twice daily for 12 weeks. After each treatment period, insulin action was assessed by a hyperinsulinaemic euglycaemic clamp, with isotope dilution methodology. After washout, treatment groups were crossed over. Fifteen patients completed the study. There were no differences in fasting glucose, or fasting insulin between treatment with eplerenone or doxazosin. The measure of overall insulin sensitivity, exogenous glucose infusion rates during the last 30 min of the clamp, was similar with both treatments; 23.4 (3.9) µmol kg(-1) min(-1) after eplerenone and 23.3 (3.6) µmol kg(-1) min(-1) after doxazosin (P=0.83). Isotopically determined fasting endogenous glucose production rates were similar after both treatments (eplerenone 9.4 (0.6) µmol kg(-1) min(-1) vs doxazosin 10.6 (0.7) µmol kg(-1) min(-1)). There was a trend for lower endogenous glucose production rates during hyperinsulinaemia following eplerenone compared with doxazosin (2.0 (0.8) µmol kg(-1) min(-1) vs 4.1 (0.9) µmol kg(-1) min(-1)). There was no difference in insulin stimulated peripheral glucose utilisation rates after treatment with eplerenone or doxazosin (25.4 (3.6) µmol kg(-1) min(-1) vs 27.0 (3.9) µmol kg(-1) min(-1)). This study gives reassuring evidence of the neutral effect of eplerenone on insulin action in hypertensive, non-diabetic patients.
Asunto(s)
Hipertensión/metabolismo , Insulina/farmacología , Antagonistas de Receptores de Mineralocorticoides/farmacología , Espironolactona/análogos & derivados , Glucemia/análisis , Estudios Cruzados , Método Doble Ciego , Eplerenona , Hipertensión Esencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Espironolactona/farmacologíaRESUMEN
In a previous 15-day, Phase II study of patients with de novo or persistent/recurrent Cushing's disease (core study), treatment with pasireotide 600 µg sc bid reduced urinary free cortisol (UFC) levels in 76% of patients and normalized UFC in 17%. The objective of this study was to evaluate the efficacy and safety of extended treatment with pasireotide. This was a planned, open-ended, single-arm, multicenter extension study (primary endpoint: 6 months). Patients aged ≥18 years with Cushing's disease who completed the core study could enter the extension if they achieved UFC normalization at core study end and/or obtained significant clinical benefit. Of the 38 patients who completed the core study, 19 entered the extension and 18 were included in the efficacy analyses (three responders, 11 reducers, four non-reducers in the core study). At data cut-off, median treatment duration in the extension was 9.7 months (range: 2 months to 4.8 years). At extension month 6, 56% of the 18 patients had lower UFC than at core baseline and 22% had normalized UFC. Of the four patients who remained on study drug at month 24, one had normalized UFC. Reductions in serum cortisol, plasma adrenocorticotropic hormone, body weight and diastolic blood pressure were observed. The most common adverse events were mild-to-moderate gastrointestinal disorders and hyperglycemia. Pasireotide offers a tumor-directed medical therapy that may be effective for the extended treatment of some patients with Cushing's disease.
Asunto(s)
Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/sangre , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/tratamiento farmacológico , Somatostatina/análogos & derivados , Hormona Adrenocorticotrópica/sangre , Adulto , Anciano , Femenino , Humanos , Hidrocortisona/sangre , Masculino , Persona de Mediana Edad , Somatostatina/uso terapéutico , Adulto JovenRESUMEN
CONTEXT: Cyclical Cushing's syndrome is detected in our center by collecting sequential early morning urine (EMU) samples for cortisol to creatinine ratio over 28 d. The Endocrine Society suggests that nocturnal salivary cortisol (NSC) may be used to assess patients for cyclical Cushing's. However, there is only very limited evidence that it correlates with EMU testing or that it demonstrates cycling over 28 d. OBJECTIVE: We sought to correlate NSC with EMU results collected the following morning and to determine whether NSC could be used to detect cyclical Cushing's. DESIGN AND SETTING: An observation study of 28-d collections for NSC and EMU was performed in a tertiary referral center over 1 yr. PATIENTS: A 28-d collection of NSC and EMU was performed in 10 patients with confirmed or suspected Cushing's syndrome. MAIN OUTCOME MEASURE: The main outcome of the study was the correlation of salivary and urinary cortisol with graphical assessment of results for cycling. RESULTS: Eleven collections were performed. One patient with cyclical Cushing's completed the collection before and after cabergoline therapy. Two hundred seventy matched salivary and urinary results were correlated (r = 0.79; P < 0.001). In two patients with cyclical Cushing's, EMU and NSC followed a similar cyclical pattern. In one patient with recurrent cyclical Cushing's, cortisol was elevated in both saliva and urine but with more prominent cycles in saliva. CONCLUSION: NSC correlated well with EMU. NSC detected all cases of cyclical Cushing's. Therefore, NSC may prove to be an additional option or replacement for EMU in detecting cyclical Cushing's syndrome.
Asunto(s)
Creatinina/orina , Síndrome de Cushing/diagnóstico , Hidrocortisona/metabolismo , Hidrocortisona/orina , Saliva/metabolismo , Adulto , Anciano , Ritmo Circadiano/fisiología , Síndrome de Cushing/metabolismo , Síndrome de Cushing/orina , Progresión de la Enfermedad , Femenino , Humanos , Hidrocortisona/análisis , Masculino , Persona de Mediana Edad , Periodicidad , Pronóstico , Saliva/química , Adulto JovenRESUMEN
CONTEXT: With adequate dose titration, pegvisomant normalizes IGF-I in up to 97% of patients with acromegaly. Pegvisomant is indicated for treatment-resistant disease but is expensive, particularly at a high dose. It has been used successfully in combination with somatostatin analogs. However, there are no therapeutic reports of pegvisomant in combination with dopamine agonists. Cabergoline is orally active, well-tolerated, and relatively inexpensive, and as monotherapy for acromegaly it is reported to normalize IGF-I in up to 30% of patients. OBJECTIVE: The aim of the study was to investigate the efficacy of cabergoline monotherapy and pegvisomant in combination with cabergoline to control serum IGF-I in patients with active acromegaly. Twenty-four patients were recruited into a United Kingdom, multicenter, open-label, prospective clinical trial. MAIN OUTCOME MEASURE: We measured the change in serum IGF-I. RESULTS: After 18 wk of dose titration to a maximum dose of 0.5 mg once daily, cabergoline monotherapy did not significantly reduce IGF-I (454 ± 219 baseline vs. 389 ± 192 ng/ml cabergoline), although two patients did normalize IGF-I. The addition of 10 mg pegvisomant daily for 12 wk significantly reduced IGF-I (389 ± 192 ng/ml cabergoline vs. 229 ± 101 ng/ml combination), and 68% achieved a normal IGF-I. Twelve weeks after cabergoline withdrawal, while continuing to receive pegvisomant 10 mg, only 26% of patients maintained an IGF-I within the reference range (229 ± 101 ng/ml combination vs. 305 ± 177 ng/ml pegvisomant). There were no significant changes in liver transaminases or glucose metabolism throughout the study. CONCLUSION: These data suggest that combination treatment with cabergoline and pegvisomant is more effective at reducing IGF-I levels than either cabergoline or pegvisomant monotherapy.
Asunto(s)
Acromegalia/tratamiento farmacológico , Agonistas de Dopamina/uso terapéutico , Ergolinas/uso terapéutico , Hormona de Crecimiento Humana/análogos & derivados , Receptores de Somatotropina/antagonistas & inhibidores , Acromegalia/sangre , Adulto , Anciano , Anciano de 80 o más Años , Cabergolina , Agonistas de Dopamina/administración & dosificación , Agonistas de Dopamina/efectos adversos , Monitoreo de Drogas , Resistencia a Medicamentos/efectos de los fármacos , Quimioterapia Combinada/efectos adversos , Ergolinas/administración & dosificación , Ergolinas/efectos adversos , Femenino , Hormona de Crecimiento Humana/administración & dosificación , Hormona de Crecimiento Humana/efectos adversos , Hormona de Crecimiento Humana/sangre , Hormona de Crecimiento Humana/uso terapéutico , Humanos , Factor I del Crecimiento Similar a la Insulina/análisis , Masculino , Persona de Mediana Edad , Pacientes Desistentes del Tratamiento , Reino UnidoRESUMEN
OBJECTIVE: Patients with primary aldosteronism (PA) who are suitable for surgery should undergo adrenal computerised tomography (CT) and adrenal venous sampling (AVS). A retrospective study was performed of 100 patients with PA. We determined the optimal AVS lateralisation ratio for unilateral disease and reviewed adrenalectomy outcomes evaluating which characteristics predicted hypertension cure. METHODS: AVS was performed in 93 patients. Lateralisation criteria were assessed using ROC curve analysis. The outcome of adrenalectomy was reviewed in 39 patients and predictive factors for cure determined using univariate and multivariate analysis. RESULTS: Of previously published criteria, ROC curve analysis found a cortisol corrected aldosterone affected to unaffected (Aldo/Cort A:U) cut-off of 2·0 was the best predictor of adenoma identifying 80·4% of patients. A novel ratio calculated by dividing the affected to unaffected ratio by the unaffected to peripheral ratio [(Aldo/Cort A:U)/(Aldo/Cort U:IVC)] was successful in identifying 87·0% of patients. Cure rate for blood pressure after adrenalectomy was 38·5% with improvement in 59·0%. On univariate analysis, predictors of post-operative hypertension were increased weight, raised creatinine, left ventricular hypertrophy (LVH) and male sex. On multivariate analysis, male sex and higher pre-operative systolic blood pressure were predictive. CONCLUSIONS: Patients with PA should have CT scanning and AVS. Aldo/Cort A:U >2·0 is the most accurate of previously published ratios in predicting unilateral disease. When patients were carefully selected for surgery, 97% had cure or improvement in blood pressure control. Further confirmatory work is required on a novel ratio which was even more predictive in our series.
Asunto(s)
Adrenalectomía , Presión Sanguínea/fisiología , Hiperaldosteronismo/cirugía , Potasio/metabolismo , Tomografía Computarizada por Rayos X , Femenino , Humanos , Hiperaldosteronismo/sangre , Masculino , Persona de Mediana Edad , Potasio/sangre , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: To compare the diagnostic performance of plasma metanephrines by ELISA and plasma catecholamine measurements by HPLC in patients selected for clonidine suppression testing. METHODS: Plasma catecholamines adrenaline (ADR) and noradrenaline (NOR) were measured by HPLC and metanephrine with normetanephrine (NMN) by ELISA (nâ=â67). The diagnostic performance of metanephrines was determined by receiver operating characteristic (ROC) curve analysis. RESULTS: Phaeochromocytoma was confirmed by histological analysis in 14 patients and excluded in 53 patients by a negative clonidine suppression test (CST), abdominal computerized tomography scan and clinical follow-up (median 2.5 years). A sensitivity and specificity of 100 and 96%, respectively, was obtained by using our current CST diagnostic criteria for ADR and NOR values. ROC curve analysis revealed optimum sensitivity and specificity for plasma-free metanephrines using a threshold of 784âpmol/l at baseline and 663âpmol/l at 180âmin. Baseline measurements of metanephrine with NMN showed 100% sensitivity and 98% specificity, as assessed by ROC curve analysis-derived criteria or when evaluated against published decision thresholds. A sensitivity and specificity of 100% was obtained for the combined measurements of metanephrine with NMN at 180âmin. CONCLUSION: Plasma metanephrines (metanephrine with NMN) were equally effective as plasma catecholamines during CST. This study supports the use of measuring plasma metanephrines by ELISA as a less labour-intensive and equally effective biochemical test for phaeochromocytoma in patients with a high clinical suspicion. There was still overlap between groups with and without phaeochromocytoma at baseline under controlled conditions and clinically some patients still need to undergo clonidine suppression testing.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/diagnóstico , Catecolaminas/sangre , Metanefrina/sangre , Feocromocitoma/diagnóstico , Neoplasias de las Glándulas Suprarrenales/sangre , Antihipertensivos , Cromatografía Líquida de Alta Presión , Clonidina , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Feocromocitoma/sangre , Valor Predictivo de las Pruebas , Curva ROCRESUMEN
The aim of this study is to review the experience of the clonidine suppression test in a regional endocrine centre and to compare the diagnostic sensitivity and specificity using various previous published criteria. The design used is retrospective study. The subjects include 56 patients in whom clonidine suppression tests had been performed from 1995 to 2000: 15 with phaeochromocytoma and 41 patients in whom the diagnosis was excluded using a combination of biochemical testing, abdominal computed tomography scanning and clinical follow-up. Plasma catecholamines were measured by high pressure liquid chromatography on basal samples and at hourly intervals for 3 h after the administration of clonidine 300 µg orally and the following diagnostic criteria were applied: plasma noradrenaline+adrenaline>2.96 nmol l(-1) at 3 h post-clonidine or a baseline plasma adrenaline plus noradrenaline>11.82 nmol l(-1); plasma noradrenaline>2.96 nmol l(-1) at 3 h post-clonidine and plasma noradrenaline>2.96 nmol l(-1) and <50% fall in noradrenaline at 3 h post-clonidine. The results obtained is that mean plasma noradrenaline plus adrenaline fell across the test in 40/41 patients in the non-phaeochromocytoma patients and was lowest at 3 h (basal 2.28 ± 0.14 vs 1.36 ± 0.11 nmol l(-1), P<0.001). In the phaeochromocytoma group, clonidine had a variable effect on adrenaline plus noradrenaline levels with increases in 7/15. Using an abnormal result as a 3 h level of noradrenaline plus adrenaline>2.96 mmol l(-1) gave a sensitivity of 93% and specificity of 95%. When a 3 h noradrenaline>2.96 mmol l(-1) was used, sensitivity was 87% and specificity 95%. Using the former criteria, noradrenaline plus adrenaline>2.96 mmol l(-1), 1/15 in the phaeochromocytoma group had a normal result after clonidine suppression testing. Two of 41 in the non-phaeochromocytoma group had a false-positive result. Under carefully controlled conditions, the clonidine suppression test is well tolerated, safe and accurate for use in the investigation of patients with suspected phaeochromocytoma.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/diagnóstico , Clonidina , Pruebas Diagnósticas de Rutina , Feocromocitoma/diagnóstico , Neoplasias de las Glándulas Suprarrenales/sangre , Antihipertensivos , Catecolaminas/sangre , Epinefrina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Norepinefrina/sangre , Feocromocitoma/sangre , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
Prior to establishing a specialist diabetic renal clinic in our unit, we studied across 12 months all 1845 patients attending one of our diabetes clinics with a serum creatinine >150 µmol/l. Diabetic control was examined along with renal function and cardiovascular risk using current audit standards. 74 such patients were identified (male:female 54:20 mean HbA1c 7.8% (sd ± 1.45) and age 64.2 years (± 12.8). 30 patients had creatinine >200 µmol/l and 15 >250 µmol/l. Using the chronic kidney disease classification, 33, 28 and 6 patients were in groups III, IV and V with 7 patients undergoing renal replacement therapy. 65% of patients met JBS2 audit standards of blood pressure using a mean of 2.93 agents (sd ± 1.43). Ace-inhibitors or angiotensin receptor blockers were used in 81% and 81% were on regular antiplatelet or anticoagulant therapy. Audit standard for total cholesterol and LDL were met in 89% and 97% of patients respectively. All patients identified in our study were in CKD class III-V and therefore we considered also alternative inclusion criteria. 136 patients had a urinary ACR ≥ 30 mg/mmol. Using this and/or the serum creatinine level above identified 197 patients from the clinic. This study shows that measurement of serum creatinine alone is not sufficiently sensitive but extended criteria identified a 10% subgroup who will now be offered detailed assessments and intensified therapies at a subspecialty in-house renal clinic. eGFR has recently been added to our computerised proforma and will enable us to further refine inclusion criteria.
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Instituciones de Atención Ambulatoria/organización & administración , Nefropatías Diabéticas/terapia , Comunicación Interdisciplinaria , Fallo Renal Crónico/terapia , Nefrología/organización & administración , Derivación y Consulta/organización & administración , Anciano , Albuminuria , Creatinina/sangre , Creatinina/orina , Nefropatías Diabéticas/diagnóstico , Nefropatías Diabéticas/fisiopatología , Progresión de la Enfermedad , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Irlanda del Norte , EspecializaciónRESUMEN
CONTEXT: Macroprolactinemia is a common finding in patients with hyperprolactinemia. There are no published long-term follow-up studies. OBJECTIVE: The aim of this study was to describe findings after prolonged follow-up in a previously published cohort of patients with macroprolactinemia. STUDY POPULATION: We studied 51 patients identified as having macroprolactinemia after polyethylene glycol precipitation. DESIGN: Clinical assessment and serum prolactin assay were repeated in 51 patients with macroprolactinemia after a median follow-up of 9.9 yr (range, 9-11 yr). RESULTS: Median age at presentation was 41 yr (range, 18-55 yr). Mean serum prolactin concentration at presentation was 1885 mU/liter, and after follow-up 1370 mU/liter. At follow-up, headache had been experienced in 12 patients (24%) and oligomenorrhea in five (10%). Galactorrhea was present in only two patients (4%). No visual deterioration was noted in 50 patients. One had a transient bitemporal hemianopia. No patients developed an autoimmune condition. Microadenoma had been identified in four patients at presentation with no new pituitary imaging abnormalities identified at follow-up. CONCLUSIONS: During prolonged follow-up, no symptomatic progression was noted in any of our patients. This study suggests that patients with macroprolactinemia and normal concentrations of monomeric prolactin can be reassured, and extended endocrine review of such patients is not required.
Asunto(s)
Hiperprolactinemia/diagnóstico , Prolactina/sangre , Adulto , Femenino , Técnica del Anticuerpo Fluorescente , Estudios de Seguimiento , Humanos , Hiperprolactinemia/sangre , EmbarazoRESUMEN
CONTEXT: Subclinical Cushing's syndrome has been described among diabetic populations in recent years, but no consensus has emerged about the value of screening. METHODS: We enrolled 201 consecutive patients attending our diabetes clinic and 79 controls. Patients with at least two of the following three criteria were offered screening using a 2300 h salivary cortisol test: glycosylated hemoglobin of at least 7%, body mass index of at least 25 kg/m(2), and a history of hypertension or blood pressure of at least 140/90 mm Hg. Results are expressed as mean +/- sem. RESULTS: Mean nighttime salivary cortisol levels were similar in the two groups (8.5 +/- 1.0 nmol/liter for diabetic patients vs. 5.8 +/- 1.0 nmol/liter for controls). Forty-seven patients (23%) had a value of at least 10 nmol/liter, which was set as a conservative threshold above which further investigation would be performed. Thirty-five (75%) agreed to further testing with a 1-mg overnight dexamethasone test. Of the remaining 12 patients, 10 were followed up clinically for at least 1 yr, and no evidence was found of the syndrome evolving. In 28 patients, serum cortisol suppressed to 60 nmol/liter or less. Of the seven patients who failed this test, four agreed to a 2 mg/d 48-h dexamethasone test, with serum cortisol suppressing to 60 nmol/liter or less in all four. Three declined this test but had normal 24-h urinary free cortisol levels. No patient had clinical features of hypercortisolism. CONCLUSIONS: The 1-3% detection rates of three recently published series have not been realized at our center where we studied a group using criteria making patients more likely to have hypercortisolism. Our results do not support the validity of screening patients without clinical features of Cushing's syndrome in the diabetes clinic.
Asunto(s)
Síndrome de Cushing/diagnóstico , Complicaciones de la Diabetes/fisiopatología , Pruebas Diagnósticas de Rutina/métodos , Hidrocortisona/análisis , Saliva/química , Índice de Masa Corporal , Síndrome de Cushing/complicaciones , Síndrome de Cushing/fisiopatología , Femenino , Hemoglobina Glucada/análisis , Humanos , Hipertensión/complicaciones , Hipertensión/fisiopatología , Masculino , Tamizaje Masivo/métodos , Persona de Mediana Edad , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: It is established that external pituitary irradiation (EPI) effectively reduces serum GH levels in acromegaly. However, its effect in normalising serum IGF1 has been disputed. We looked at the number of our patients who achieved persistently normal IGF1 levels whilst free of adjunctive treatment for at least 1 year after EPI. PATIENTS AND DESIGN: We identified 63 acromegalic patients between 1964 and 2004 who received EPI. Six were excluded: three had surgery after EPI, two had no medical records available, and one had a pituitary Yttrium implant. MEASUREMENTS: Patients received 4500-5000 cGy in fractionated doses. IGF1 levels were correlated with their respective age-related reference ranges. RESULTS: After EPI, the number of patients with normal IGF1 and free of adjunctive medical treatment for at least 1 year were four patients by 3 years, nine patients by 5 years and seventeen by 10 years, with the current number of 25/57 (44%). Concordance between IGF1 levels and random GH dropped from 90% at the time of EPI to 65% at 3 years, 66% at 5 years and 71% at 10 years. CONCLUSIONS: We have demonstrated that, with time, EPI achieves a normal IGF1 in significant numbers of patients with acromegaly, thus obviating the need for life-long expensive medical therapy. For each patient this benefit has to be weighed against the possibility of new hypopituitarism as a result of the treatment. Any decision to use EPI is easier in the context of pre-existent hypopituitarism.
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Acromegalia/metabolismo , Acromegalia/radioterapia , Factor I del Crecimiento Similar a la Insulina/metabolismo , Hipófisis/efectos de la radiación , Radioterapia/efectos adversos , Acromegalia/etiología , Adenoma/complicaciones , Adenoma/radioterapia , Adolescente , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Terapia de Reemplazo de Hormonas , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/radioterapia , Estudios Retrospectivos , Adulto JovenRESUMEN
Light microscopic studies comparing sperm parameters show little association between diabetes and male fertility. However, with the introduction of new analytical techniques, evidence is now emerging of previously undetectable effects of diabetes on sperm function. Specifically, a recent study has found a significantly higher sperm nuclear DNA fragmentation in diabetic men. As advanced glycation end products (AGEs) are important instigators of oxidative stress and cell dysfunction in numerous diabetic complications, we hypothesized that these compounds could also be present in the male reproductive tract. The presence and localization of the most prominent AGE, carboxymethyl-lysine (CML), in the human testis, epididymis and sperm was determined by immunohistochemistry. Parallel ELISA and Western blot analyses were performed to ascertain the amount of CML in seminal plasma and sperm from 13 diabetic and nine non-diabetic subjects. CML immunoreactivity was found throughout the seminiferous epithelium, the nuclei of spermatogonia and spermatocytes, in the basal and principle cells cytoplasm and nuclei of the caput epididymis and on most sperm tails, mid pieces and all cytoplasmic droplets. The acrosomal cap, especially the equatorial band, was prominently stained in diabetic samples only. The amount of CML was significantly higher (p = 0.004) in sperm from non-diabetic men. Considering the known detrimental actions of AGEs in other organs, the presence, location and quantity of CML, particularly the increased expression found in diabetic men, suggest that these compounds may play a hitherto unrecognized role in male infertility.
Asunto(s)
Diabetes Mellitus/metabolismo , Epidídimo/química , Productos Finales de Glicación Avanzada/análisis , Lisina/análogos & derivados , Semen/química , Espermatozoides/química , Testículo/química , Adulto , Western Blotting , Estudios de Casos y Controles , Complicaciones de la Diabetes/etiología , Complicaciones de la Diabetes/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunohistoquímica , Infertilidad Masculina/etiología , Infertilidad Masculina/metabolismo , Lisina/análisis , MasculinoRESUMEN
AIMS: To establish the safety in terms of insulin sensitivity of a low dose thiazide/ACE inhibitor combination. METHODS: We examined the effects on insulin sensitivity of captopril either alone or in combination with low-dose bendroflumethiazide (1.25 mg) in 15 hypertensive Type 2 diabetic patients. Insulin action was assessed using an isoglycaemic hyperinsulinaemic clamp in a double-blind, randomised, crossover study after a 6-week placebo run-in and following two 12-week treatment periods with captopril (C) (100 mg) alone or in combination with bendroflumethiazide (CB) (1.25 mg). RESULTS: Blood pressure was lower following CB compare to C (138/83 vs. 144/85 mmHg; P < 0.05) and both were lower than baseline (153/92 mmHg; P < 0.01). CB resulted in a significant increase in fasting plasma glucose compared to C (9.6 +/- 2.6 vs. 8.5 +/- 1.6 mmol/l; P < 0.05). Exogenous glucose infusion rates required to maintain isoglycaemia during hyperinsulinaemia were lower after CB compared to C (25.1 +/- 13.3 vs. 34.2 +/- 16.8 micromol/kg/min; P < 0.01) as were isotopically determined glucose utilisation rates (29.0 +/- 12.4 vs. 36.6 +/- 17.3 micromol/kg/min; P < 0.05). There was no significant difference in fasting endogenous glucose production between treatments (CB 9.3 +/- 3.3 vs. C 8.6 +/- 1.6 micromol/kg/min), nor between suppression following insulin (CB 4.0 +/- 2.1 vs. C 4.3 +/- 3.1 micromol/kg/min). CONCLUSIONS: Combination of low-dose bendroflumethiazide with captopril lowered blood pressure but resulted in deleterious effects on insulin action compared to captopril alone.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Antihipertensivos/administración & dosificación , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Angiopatías Diabéticas/tratamiento farmacológico , Hipertensión/tratamiento farmacológico , Adulto , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Antihipertensivos/efectos adversos , Bendroflumetiazida/administración & dosificación , Bendroflumetiazida/efectos adversos , Captopril/administración & dosificación , Captopril/efectos adversos , Estudios Cruzados , Método Doble Ciego , Quimioterapia Combinada , Técnica de Clampeo de la Glucosa/métodos , Humanos , Insulina/farmacología , Resistencia a la Insulina , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
The effects of diabetes mellitus on male reproductive health have not been clearly defined. A previous publication from this group reported significantly higher levels of nuclear DNA fragmentation and mitochondrial DNA deletions in spermatozoa from men with type 1 diabetes. This study compared semen profiles, sperm DNA fragmentation and levels of oxidative DNA modification in spermatozoa of diabetic and non-diabetic men. Semen samples from 12 non-diabetic, fertile men and 11 type 1 diabetics were obtained and subjected to conventional light microscopic semen analysis. Nuclear DNA fragmentation was assessed using an alkaline Comet assay and concentrations of 7,8-dihydro-8-oxo-2-deoxyguanosine (8-OHdG), an oxidative adduct of the purine guanosine, were assessed by high-performance liquid chromatography. Conventional semen profiles were similar in both groups, whilst spermatozoa from type 1 diabetics showed significantly higher levels of DNA fragmentation (44% versus 27%; P < 0.05) and concentrations of 8-OHdG (3.6 versus 2.0 molecules of 8-OHdG per 10(5) molecules of deoxyguanosine; P < 0.05). Furthermore, a positive correlation was observed between DNA fragmentation and concentrations of 8-OHdG per 10(5) molecules of deoxyguanosine (rs = 0.7, P < 0.05). The genomic damage evident in spermatozoa of type 1 diabetics may have important implications for their fertility and the outcome of pregnancies fathered by these individuals.
Asunto(s)
Fragmentación del ADN , Desoxiguanosina/análogos & derivados , Diabetes Mellitus Tipo 1/metabolismo , Estrés Oxidativo/fisiología , Espermatozoides/metabolismo , 8-Hidroxi-2'-Desoxicoguanosina , Estudios de Casos y Controles , Desoxiguanosina/metabolismo , Humanos , Masculino , Semen/citologíaAsunto(s)
Carcinoma/diagnóstico por imagen , Radioisótopos de Yodo/uso terapéutico , Neoplasias de la Tiroides/diagnóstico por imagen , Tirotropina/sangre , Tiroxina/administración & dosificación , Carcinoma/sangre , Carcinoma/tratamiento farmacológico , Carcinoma/patología , Diferenciación Celular , Auditoría Clínica , Humanos , Persona de Mediana Edad , Cintigrafía , Neoplasias de la Tiroides/sangre , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/patología , Tiroidectomía/métodos , Privación de TratamientoRESUMEN
AIMS: Phaeochromocytomas are rare but potentially life-threatening neuroendocrine tumours of the adrenal medulla or sympathetic nervous system ganglia. There are no histological features which reliably differentiate benign from malignant phaeochromocytomas. The aim of the study was to evaluate cyclooxygenase (COX)-2 and Bcl-2 as tissue-based biomarkers of phaeochromocytoma prognosis. METHODS AND RESULTS: COX-2 and Bcl-2 expression were examined immunohistochemically in tissue from 41 sporadic phaeochromocytoma patients followed up for a minimum of 5 years after diagnosis. There was a statistically significant association between COX-2 histoscore (intensity x proportion) and the development of tumour recurrence or metastases (P = 0.006). A significant relationship was observed between coexpression of COX-2 and Bcl-2 in the primary tumour and the presence of recurrent disease (P = 0.034). A highly significant association was observed between (i) tumour-associated expression of these two oncoproteins (P = 0.001) and (ii) COX-2 histoscore and the presence of Bcl-2 expression (P = 0.002). COX regression analysis demonstrated no significant relationship between (i) the presence or absence of either COX-2 or Bcl-2 and patient survival or (ii) COX-2 histoscore and patient survival. CONCLUSIONS: COX-2 and Bcl-2 may promote phaeochromocytoma malignancy, and these oncoproteins may be valuable surrogate markers of an aggressive tumour phenotype.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/metabolismo , Biomarcadores de Tumor/análisis , Ciclooxigenasa 2/biosíntesis , Feocromocitoma/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Adolescente , Neoplasias de las Glándulas Suprarrenales/mortalidad , Neoplasias de las Glándulas Suprarrenales/patología , Adulto , Anciano , Femenino , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Feocromocitoma/mortalidad , Feocromocitoma/patologíaRESUMEN
BACKGROUND: Diabetes mellitus (DM) is increasing in men of reproductive age. Despite this, the prevalence of diabetes in men attending fertility clinics is largely unknown. Furthermore, studies examining the effects of DM on sperm fertility potential have been limited to conventional semen analysis. METHODS: Conventional semen analysis (semen volume, sperm count, motility and morphology) was performed for 27 diabetic (mean age 34+/-2 years) and 29 non-diabetic subjects (control group, men undergoing routine infertility investigations, mean age 33+/-1 years). Nuclear DNA (nDNA) fragmentation was assessed using the alkaline Comet assay and mitochondrial DNA (mtDNA) deletions by Long-PCR. RESULTS: Other than a small, but significant, reduction in semen volume in diabetic men (2.6 versus 3.3 ml; P<0.05), conventional semen parameters did not differ significantly from control subjects. Diabetic subjects had significantly higher mean nDNA fragmentation (53 versus 32%; P<0.0001) and median number of mtDNA deletions (4 versus 3; P<0.05) compared with control subjects. CONCLUSIONS: Diabetes is associated with increased sperm nuclear and mtDNA damage that may impair the reproductive capability of these men.