RESUMEN
Adiponectin, an adipose tissue secreted protein, exhibits anti-inflammatory and antiatherogenic properties. We examined the effects of the globular and full-length adiponectin on cytokine production in macrophages derived from Coronary Artery Disease (CAD) patients and control individuals. Adiponectin's effects in human macrophages upon lipopolysaccharide (LPS) treatment were also examined. Full length adiponectin acted differently on TNF-α and IL-6 production by upregulating TNF-α and IL-6 protein production, but not their mRNA expression. Additionally, full length adiponectin was unable to abrogate LPS proinflammatory effect in TNF-α and IL-6 mRNA expression in CAD and NON-CAD macrophages. In contrast, globular adiponectin appeared to have proinflammatory properties by potently upregulating TNF-α and IL-6 mRNA and protein secretion in human macrophages while subsequently rendered cells resistant to further proinflammatory stimuli. Moreover, both forms of adiponectin powerfully suppressed scavenger MSR-AI mRNA expression and augmented IL-10 protein release, both occurring independently of the presence of LPS or CAD. These data indicate that adiponectin could potentially protect human macrophages via the elevated IL-10 secretion and the suppression of MSR-AI expression. It can also be protective in CAD patients since the reduced adiponectin-induced IL-6 release in CAD macrophages compared to controls, could be beneficial in the development of inflammation related atherosclerosis.
Asunto(s)
Adiponectina/farmacología , Enfermedad de la Arteria Coronaria/patología , Interleucina-10/biosíntesis , Interleucina-6/biosíntesis , Macrófagos/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Ratones , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Depuradores de Clase A/genética , Receptores Depuradores de Clase A/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Adrenal incidentalomas (AIs) represent adrenal masses that are incidentally discovered whilst investigating symptoms and signs unrelated to adrenal pathology. The onset and natural course of AIs are unknown, and the possible underlying cardiometabolic abnormalities have not been examined in depth. A growing body of clinical and experimental evidence supports the notion that both functioning and, paradoxically, nonfunctioning AIs are associated with a partially expressed or even full-blown metabolic syndrome (MS) phenotype, through yet unclear mechanisms. Subtle, subclinical or even profound adrenal hormone excess and an increased proinflammatory state might explain to some extent the development of MS disturbances. The emerging association between AIs and MS appears to be important in determining the optimal clinical management of these patients and raises speculation about the exact mechanisms of this interesting cause-effect relationship.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/complicaciones , Síndrome Metabólico/complicaciones , Neoplasias de las Glándulas Suprarrenales/metabolismo , Neoplasias de las Glándulas Suprarrenales/cirugía , Adrenalectomía , Síndrome de Cushing/complicaciones , Humanos , Hidrocortisona/metabolismo , Hallazgos IncidentalesRESUMEN
OBJECTIVE: Although insulin resistance in obesity is established, information on insulin action on lipid fluxes, in morbid obesity, is limited. This study was undertaken in morbidly obese women to investigate insulin action on triacylglycerol fluxes and lipolysis across adipose tissue. SUBJECTS AND DESIGN: A meal was given to 26 obese (age 35+/-1 years, body mass index 46+/-1 kg m(-2)) and 11 non-obese women (age 38+/-2 years, body mass index 24+/-1 kg m(-2)). Plasma samples for glucose, insulin, triglycerides and non-esterified fatty acids (NEFAs) were taken for 360 min from a vein draining the abdominal subcutaneous adipose tissue and from the radial artery. Adipose tissue blood flow was measured with (133)Xe. RESULTS: In obese vs non-obese: (1) Arterial glucose was similar, but insulin was increased (P=0.0001). (2) Adipose tissue blood flow was decreased (P=0.0001). (3) Arterial triglycerides (P=0.0001) and NEFAs (P=0.01) were increased. (4) Lipoprotein lipase was decreased (P=0.0009), although the arteriovenous triglyceride differences were similar. (5) Veno-arterial NEFA differences across the adipose tissue were similar. (6) NEFA fluxes and hormone-sensitive lipase-derived glycerol output from 100 g adipose tissue were not different. (7) Total adipose tissue NEFA release was increased (P=0.02). CONCLUSIONS: In morbid obesity: (a) hypertriglycerinemia could be attributed to a defect in the postprandial dynamic adjustment of triglyceride clearance across the adipose tissue, partly caused by blunted BF; and (b) postprandially, there is an impairment of adipose tissue to buffer NEFA excess, despite hyperinsulinemia.
Asunto(s)
Tejido Adiposo/metabolismo , Glucemia/metabolismo , Insulina/fisiología , Lipólisis , Lipoproteína Lipasa/metabolismo , Obesidad Mórbida/metabolismo , Periodo Posprandial , Adulto , Índice de Masa Corporal , Femenino , Humanos , Hipertrigliceridemia/etiología , Triglicéridos/metabolismoRESUMEN
OBJECTIVE: The metabolic syndrome (MetS) is a cluster of risk factors related to cardiovascular disease. Prediabetes, identified by impaired fasting glucose and/or impaired glucose tolerance, may predict future development of diabetes mellitus. However, it is not clear whether MetS and prediabetes represent the same or different clinical entities. This study compares MetS and prediabetes in terms of cardiovascular risk factors and target organ damage. RESEARCH DESIGN AND METHODS: A total of 524 overweight and obese (body mass index, BMI >or= 27 kg/m (2)) adults, mean age 53.6 +/- 10.3 years, 264 men and 260 women, were studied. All participants underwent a thorough clinical and laboratory evaluation, including an oral glucose tolerance test and insulin measurements. Echocardiography, carotid ultrasonography, and pulse wave analysis were also performed for the detection of target organ damage. NCEP-ATP III and ADA criteria were used for the diagnosis of MetS and prediabetes. RESULTS: The prevalence of MetS and prediabetes was 38.7 and 25.4 %, respectively. Overall, 129 individuals (24.6 %) had MetS without prediabetes (group M) and another 59 (11.3 %) prediabetes without MetS (group P). Group P had decreased albumin excretion (p = 0.033) and more thickened common carotid intima-media in comparison to group M (p = 0.032). Furthermore, group M was associated with higher C-reactive protein levels. Multiple logistic regression analysis revealed that advanced age (p < 0.0001, OR 1.11, 95 % CI 1.06 - 1.16), low insulin secretion (p < 0.0001, OR 0.05, 95 % CI 0.02 - 0.18 for insulinogenic index), and increased insulin resistance (p = 0.0003, OR 3.22, 95 % CI 1.71 - 6.07 for HOMA-IR) were associated with group P. CONCLUSIONS: Our data demonstrate that MetS and prediabetes have an overlapping pattern. MetS appears to have a more pronounced effect on early renal dysfunction and increased inflammatory activation, while prediabetes tends to be associated with early carotid structural changes. These findings may be due to a different pathophysiologic substrate of these clinical phenotypes in terms of insulin resistance and secretion, as well as to the varying prevalence of cardiovascular risk factors.
Asunto(s)
Síndrome Metabólico/clasificación , Sobrepeso , Estado Prediabético/clasificación , Adulto , Anciano , Estudios de Cohortes , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Anamnesis , Síndrome Metabólico/diagnóstico , Persona de Mediana Edad , Obesidad/epidemiología , Estado Prediabético/diagnósticoRESUMEN
AIMS: This study is an investigation of the impact of Type 1 diabetes on bone mineral density (BMD) with regard to bone composition. MATERIAL AND METHODS: Thirty male and 30 premenopausal female patients with Type 1 diabetes (IDD) were retrospectively compared with an equal number of healthy individuals, matched on a person-to-person basis and to the reference population mean. BMD was measured at the L2-L4 vertebrae and femoral neck (FN) by dual energy X-ray absorptiometry (DXA). RESULTS: BMD absolute values were significantly lower in the diabetic than in the healthy males at vertebrae and FN (P<.05). The vertebral BMD values of diabetic women did not significantly differ, whereas those of FN were significantly lower compared with those of the healthy participants. FN age-adjusted BMD values (Z scores) were significantly lower than those of the healthy persons and the population reference mean in both genders (P=.01, <.001 for males and <.01 for females), whereas regarding the vertebrae, only in the diabetic males (P<.05 and <.01 respectively). The percentages of osteopenia and osteoporosis were significantly higher in the male compared to the female diabetic patients (P<.001). No significant correlations existed between the BMD values and diabetes duration, glycosylated hemoglobin (HbA1c) concentration, or age of diabetes onset. Similar results were obtained when applying stepwise multiple regression analysis to explain the BMD value variance. CONCLUSIONS: Young males with Type 1 diabetes exhibit significantly lower BMD values of trabecular and mixed cortical-trabecular bone, compared with matched healthy persons. Premenopausal females with Type 1 diabetes present significantly lower BMD values of mixed bone only. Blood glucose control and diabetes duration do not appear to influence BMD behavior.
Asunto(s)
Densidad Ósea/fisiología , Enfermedades Óseas Metabólicas/complicaciones , Diabetes Mellitus Tipo 1/complicaciones , Osteoporosis/complicaciones , Absorciometría de Fotón , Adulto , Índice de Masa Corporal , Enfermedades Óseas Metabólicas/diagnóstico , Estudios de Casos y Controles , Diabetes Mellitus Tipo 1/fisiopatología , Femenino , Cuello Femoral/anatomía & histología , Cuello Femoral/fisiología , Humanos , Masculino , Análisis por Apareamiento , Osteoporosis/diagnóstico , Valores de Referencia , Factores Sexuales , Columna Vertebral/anatomía & histología , Columna Vertebral/fisiologíaRESUMEN
Vertebral bone mineral density (BMD) measurements by DXA are considered reliable indicators of local fracture risk in the absence of radiographic deformities. The clinical evaluation of one individual vertebra presenting a BMD value significantly less than the others is attempted in this study. For a period of 30 months, BMD measurements of L1-L4 vertebrae and femoral neck (FN) were performed by DXA in 817 postmenopausal women, aged under 65 years, with a BMI less than 33 kg/m(2). In 204 (25%) of these women (group A), the least dense vertebra (LDV) presented a BMD value lower than 92.4% from the immediate denser vertebra. The remaining 613 women comprised group B. Women with X-ray proven vertebral degenerative lesions or deformities were excluded from the study. Among the four measured vertebrae, L1 was the most frequent LDV (47%), whilst L3 was the most rare (2%). Absolute and age-adjusted BMD values of L1-L4 and FN, as well as the proportions of osteopenic or osteoporotic women, did not differ significantly between the two groups. A significant positive correlation was observed between either L1-L4 or LDV and FN BMD values in both groups, but stepwise multiple regression analysis revealed that in group A the LDV did not participate in the model explaining the variability of the FN BMD values. In group B, the least dense vertebra was the only variable participating in the respective model (adjusted-R(2) = 37.7%). It is concluded that in a significant proportion of relatively young postmenopausal women, a wide variance of BMD values exists between individual vertebral BMD values without radiographic background. L1 was the most frequent LDV and L3 the most rare. In such cases, the evaluation of the least dense vertebra seems to offer an alternative estimation of vertebral bone mass, instead of mean L1-L4.
Asunto(s)
Absorciometría de Fotón/métodos , Densidad Ósea/fisiología , Cuello Femoral/fisiopatología , Vértebras Lumbares/fisiopatología , Osteoporosis Posmenopáusica/diagnóstico , Enfermedades Óseas Metabólicas/diagnóstico , Enfermedades Óseas Metabólicas/fisiopatología , Femenino , Humanos , Persona de Mediana Edad , Osteoporosis Posmenopáusica/fisiopatología , Posmenopausia/fisiología , Análisis de Regresión , Estadísticas no ParamétricasRESUMEN
AIM: The metabolic syndrome (MetS) is a cluster of cardiovascular risk factors, while prediabetes, identified by impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT), predicts future development of diabetes mellitus. Although MetS and prediabetes have a strong interrelation, it is unclear whether they denote the same risk for cardiovascular complications. The aim of the study was to compare overweight and obese individuals with MetS and prediabetes in terms of early carotid artery atheromatosis and renal dysfunction. METHODS: A total of 524 overweight and obese (body mass index, BMI = or >27 kg/m2) adults, mean age 56.7+/-11.8 years, 264 men and 260 women, were studied. All participants underwent a thorough clinical and laboratory evaluation, including an oral glucose tolerance test. Carotid artery ultrasonography was performed and 24 h urine albumin excretion was measured. NCEP-ATP III and ADA criteria were used for the diagnosis of MetS and prediabetes. RESULTS: Overall, 129 individuals (24.6%) had MetS without prediabetes and another 59 (11.3%) prediabetes without MetS. Individuals with prediabetes had lower albumin excretion (P=0.033) and more thickened common carotid intima-media in comparison to those with MetS (P=0.032). Furthermore, MetS was associated with higher C-reactive protein levels in comparison to prediabetes (P=0.05). CONCLUSIONS: The MetS seems to have a more pronounced impact on early renal dysfunction than prediabetes, while the latter to early carotid artery structural changes.
Asunto(s)
Enfermedades de las Arterias Carótidas/etiología , Arteria Carótida Común/diagnóstico por imagen , Síndrome Metabólico/complicaciones , Estado Prediabético/complicaciones , Adulto , Anciano , Índice de Masa Corporal , Proteína C-Reactiva/metabolismo , Enfermedades de las Arterias Carótidas/sangre , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/diagnóstico por imagen , Persona de Mediana Edad , Estado Prediabético/sangre , Estado Prediabético/diagnóstico por imagen , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Ultrasonografía DopplerRESUMEN
AIM: To compare endoscopic banding ligation vs. no treatment in cirrhotics with intolerance or contraindications to beta-blockers for prevention of first bleeding in portal hypertension. METHODS: A sample size of 214 was planned with all sizes of varices. However, the trial was stopped due to increased bleeding in 52 patients in the ligation group. The baseline severity liver disease and endoscopic features were similar. Ligation group: 25 (M/F = 21/4, mean age: 60 +/- 9.37 years); 27 not-treated group: 27 (M/F = 17/10, mean age: 63 +/- 10.27). RESULTS: The mean follow-up period was 19.5 +/- 13.3 months: five bled in the ligation group (20%), three from varices (two after banding at 11 and 17 days; one during the procedure), and two from gastropathy; two bled in the not-treated group (7%- two both varices) (P = 0.24). There were seven deaths in the ligation group and 11 in the not-treated group (P = 0.39). CONCLUSION: Sixty per cent of the bleeding in the banding group was probably iatrogenic, requiring the study to be stopped. Endoscopic banding ligation was no better than no treatment. This study suggests that ligation may be harmful when used as primary prophylaxis, similar to prophylactic sclerotherapy in the past.
Asunto(s)
Antagonistas Adrenérgicos beta , Endoscopía Gastrointestinal/métodos , Várices Esofágicas y Gástricas/prevención & control , Hemorragia Gastrointestinal/prevención & control , Cirrosis Hepática/complicaciones , Causas de Muerte , Contraindicaciones , Várices Esofágicas y Gástricas/cirugía , Femenino , Humanos , Hipertensión Portal/complicaciones , Ligadura/métodos , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
OBJECTIVE: Premature menopause is a known risk factor for osteoporosis, whilst the influence of type 2 diabetes on bone mineral density (BMD) is still controversial. DESIGN AND METHODS: BMD values assessed by dual-energy X-ray absorptiometry (DXA) in L2-L4 vertebrae and the femoral neck (FN) of 40 diabetic women with premature menopause (D-EMP) were compared with those of 60 non-diabetic, prematurely menopausal women (EMP) and 60 diabetic women with normal menopause (D-NMP) who had been matched by age and body mass index (BMI). In all women, the time elapsed since menopause ranged between 10 and 25 years and the duration of diabetes exceeded 75% of the postmenopausal time period. The age of D-EMP women was 58.7+/-5 years (mean+/-1 s.d.), age at menopause 39.5+/-2.7, years since menopause 18.6+/-4.9, BMI 27.8+/-4.3 kg/m(2) and duration of diabetes 13.9+/-3.9 years. RESULTS: Vertebral BMD values of D-EMP women were significantly higher than those of EMP women (0.908+/-0.135 vs. 0.817+/-0.14 g/cm(2), P = 0.002), although there was no significant difference between D-EMP and D-NMP women (0.886+/-0.15 g/cm(2)). No significant differences were observed in FN BMD values between all groups. Age-adjusted BMD values (Z scores) of D-EMP women were higher than EMP women in both anatomic sites (P < 0.01), but did not differ from D-NMP women. In contrast to the other two groups, no statistically significant correlation was observed in D-EMP women between the BMD values of either anatomic area and the time elapsed since menopause. HbA(1c) values were positively correlated only to vertebral BMD values of the D-EMP group (P < 0.05). No correlation was observed between the BMD values and the duration of diabetes either in D-EMP or in D-NMP women. CONCLUSIONS: Type 2 diabetes seems to positively affect the mineral density of the trabecular bone in women with premature menopause. The duration of diabetes does not appear to influence bone mass.
Asunto(s)
Densidad Ósea , Diabetes Mellitus Tipo 2/fisiopatología , Menopausia Prematura/metabolismo , Absorciometría de Fotón , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/diagnóstico por imagen , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Cuello Femoral/diagnóstico por imagen , Hemoglobina Glucada/metabolismo , Humanos , Vértebras Lumbares/diagnóstico por imagen , Menopausia Prematura/sangre , Persona de Mediana Edad , Factores de TiempoRESUMEN
OBJECTIVE: This study investigates the association of homocysteine and cortisol with psychological factors in type 2 diabetic patients. METHOD: Homocysteine, cortisol, and psychological variables were analyzed from 131 diabetic patients. Psychological factors were assessed with the Eysenck Personality Questionnaire (EPQ), Hostility and Direction of Hostility Questionnaire (HDHQ), the Symptom Checklist 90-R (SCL 90-R), the Zung Self-Rating Depression Scale (ZDRS), and the Maudsley O-C Inventory Questionnaire (MOCI). Blood samples were taken by measuring homocysteine and cortisol in both subgroups during the initial phase of the study (T0). One year later (T1), the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments and with an identical blood analysis. RESULTS: The relation of psychoticism and homocysteine is positive among controlled diabetic patients (P value = 0.006 < 0.05) and negative among uncontrolled ones (P value = 0.137). Higher values of cortisol correspond to lower scores on extraversion subscale (r(p) = -0.223, P value = 0.010). Controlled diabetic patients showed a statistically significant negative relationship between homocysteine and the act-out hostility subscale (r(sp) = -0.247, P = 0.023). There is a statistically significant relationship between homocysteine and somatization (r(sp) = -0.220, P = 0.043). CONCLUSIONS: These findings support the notion that homocysteine and cortisol are related to trait and state psychological factors in patients with diabetes mellitus type 2.
Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/psicología , Homocisteína/sangre , Hidrocortisona/sangre , Trastornos Psicóticos/sangre , Anciano , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Escalas de Valoración Psiquiátrica , Psicometría , Psicopatología , Trastornos Psicóticos/complicaciones , Encuestas y CuestionariosRESUMEN
BACKGROUND/OBJECTIVES: Previous studies support the glucose-lowering effect of vinegar. However, the effect of vinegar on muscle glucose metabolism and endothelial function has not been studied in humans. This open, randomized, crossover, placebo-controlled study aims to investigate the effects of vinegar on muscle glucose metabolism, endothelial function and circulating lipid levels in subjects with impaired glucose tolerance (IGT) using the arteriovenous difference technique. SUBJECTS/METHODS: Eight subjects with IGT (4 males, age 46±10 years, body mass index 30±5) were randomised to consume 0.50 mmol vinegar (6% acetic acid) or placebo before a mixed meal. Plasma samples were taken for 300 min from the radial artery and the forearm vein for measurements of glucose, insulin, triglycerides, non-esterified fatty acids (NEFAs) and glycerol. Muscle blood flow was measured with strain gauge plethysmography. Glucose flux was calculated as the arteriovenous difference of glucose multiplied by the blood flow rates. RESULTS: Vinegar compared with placebo: (1) decreased arterial plasma insulin (Poverall<0.001; P75 min=0.014, ß=-42), (2) increased forearm blood flow (Poverall<0.001; P240 min=0.011, ß=1.53; P300 min=0.023, ß=1.37), (3) increased muscle glucose uptake (Poverall<0.001; P60 min=0.029, ß=2.78) and (4) decreased arterial plasma triglycerides (Poverall=0.005; P240 min<0.001, ß=-344; P300 min<0.001, ß=-373), without changing NEFA and glycerol. CONCLUSIONS: In individuals with IGT, vinegar ingestion before a mixed meal results in an enhancement of muscle blood flow, an improvement of glucose uptake by the forearm muscle and a reduction of postprandial hyperinsulinaemia and hypertriglyceridaemia. From this point of view, vinegar may be considered beneficial for improving insulin resistance and metabolic abnormalities in the atherogenic prediabetic state.
Asunto(s)
Absorción Fisiológica , Ácido Acético/uso terapéutico , Bebidas , Glucemia/metabolismo , Músculo Esquelético/metabolismo , Estado Prediabético/dietoterapia , Flujo Sanguíneo Regional , Adulto , Glucemia/análisis , Índice de Masa Corporal , Estudios Cruzados , Endotelio Vascular/metabolismo , Endotelio Vascular/fisiopatología , Femenino , Antebrazo , Humanos , Hiperinsulinismo/etiología , Hiperinsulinismo/prevención & control , Hipertrigliceridemia/etiología , Hipertrigliceridemia/prevención & control , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Músculo Esquelético/irrigación sanguínea , Sobrepeso/complicaciones , Pletismografía , Periodo Posprandial , Estado Prediabético/complicaciones , Estado Prediabético/metabolismo , Estado Prediabético/fisiopatologíaRESUMEN
Insulin-induced hypoglycemia causes a sequential stimulation of all three components of the hypothalamic-pituitary-adrenal axis. States of acute glucocorticoid excess, such as the overnight (1 mg) dexamethasone suppression test (DST), inhibit both the basal cortisol level and the response to an insulin tolerance test (ITT). However, whether this negative feedback effect is exerted primarily at the hypothalamic or the pituitary level is not clear. To explore this question further we have examined the cortisol response to insulin-induced hypoglycemia in three experimental settings, in the following order: 1) a control ITT performed at 0900 h after an overnight hospital stay (cITT); 2) an ITT at 0900 h after oral dexamethasone, 1 mg, at 2300 h on the previous evening (DST + ITT); and 3) an ITT at 0900 h after dexamethasone, 1 mg, at 2300 h and hCRH, 1 microgram/kg iv, at 90 min intervals from 0100-0700 h (DST+hCRH + ITT). The response to ITT was defined as the peak cortisol increment (peak minus baseline). Since the study objective was to test whether overnight pulsatile hCRH could prevent dexamethasone-induced suppression of the response to a morning ITT, only subjects that demonstrated a greater than 25% decrease in the cortisol response to DST + ITT vs. cITT received the full protocol (five of nine normal men). Basal ACTH and cortisol secretion remained suppressed throughout the night during both the Dex + ITT and Dex + hCRH + ITT studies when compared to the control study (cITT, P < 0.05). However, the cortisol response to hypoglycemia during DST + hCRH + ITT was significantly greater than during DST+ITT (P < 0.05) and was similar to the cITT response. Thus, pulsatile hCRH, administered during the 10 h between dexamethasone and the subsequent hypoglycemic stimulus, prevented acute suppression by dexamethasone of the cortisol response to hypoglycemia. We conclude that the dexamethasone-induced inhibition of the cortisol response to hypoglycemia results primarily from suppression by dexamethasone of basal hypothalamic corticotropin-releasing factor and the consequent impairment of corticotroph responsiveness to exogenous and endogenous corticotropin-releasing factor.
Asunto(s)
Hormona Liberadora de Corticotropina/farmacología , Dexametasona/farmacología , Hidrocortisona/sangre , Hipoglucemia/sangre , Hormona Adrenocorticotrópica/sangre , Adulto , Glucemia/análisis , Ritmo Circadiano , Dexametasona/antagonistas & inhibidores , Humanos , Insulina/farmacología , Masculino , Flujo Pulsátil , Valores de ReferenciaRESUMEN
The role of desmopressin, alone or in combination with CRH, in the differential diagnosis between Cushing's disease (CD) and ectopic ACTH secretion (EAS) still remains uncertain. Based on existing data, the desmopressin test is regarded as an alternative to the CRH stimulation test and, when given in combination with CRH, it has been suggested to completely discriminate between patients with CD and EAS. However, assessment of these tests has been limited in only a small number of patients with EAS. Desmopressin is a relatively specific V2 vasopressin receptor (V2R) agonist. Although expression of V3 vasopressin receptor (V3R) is common in tumors with EAS, the expression of V2R has not been extensively investigated. In the present study, we report our findings of the desmopressin and the combined CRH-desmopressin test in a series of patients with CD and EAS; also, the expression of V2R and V3R was investigated in tumors with EAS by a RT-PCR method. We assessed a cohort of 31 patients with ACTH-dependent Cushing's syndrome, including 26 patients with CD and five cases with histologically confirmed EAS. To avoid bias of predetermined criteria, univariate curves of the receiver operating characteristics (ROC) were constructed by plotting the sensitivity against 1-specificity at each level of the percent cortisol (F) and ACTH responses to these tests. Following desmopressin administration there was an overlap of the percent F and ACTH responses among patients with CD and EAS, and the area under the ROC curve for both these responses was not significantly different than that occurring by chance. This was also true for the percent F response following the combined CRH-desmopressin test. However, the area under the ROC curve for the percent ACTH rise following the combined test was significantly different; the point of the ROC curve closest to 1 corresponded to a percent ACTH rise of 218% (88% sensitivity and 80% specificity). Expression of V2R and V3R mRNA was investigated in four of the five excised tumors with EAS and revealed the presence of the V2R in all, whereas the V3R mRNA was expressed in three of these cases. In conclusion, in this series the desmopressin test produced a significant overlap of responses between CD and patients with EAS and, therefore, is of limited value in the differential diagnosis of the ACTH-dependent Cushing's syndrome. This is most probably due to the expression of the V2R in tumors with EAS. Moreover, following the combined CRH-desmopressin test only the ACTH but not the F responses were diagnostically useful, but still far from completely discriminating patients with CD and EAS.
Asunto(s)
Síndrome de ACTH Ectópico/diagnóstico , Hormona Adrenocorticotrópica/fisiología , Hormona Liberadora de Corticotropina , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/etiología , Desamino Arginina Vasopresina , Síndrome de ACTH Ectópico/metabolismo , Adulto , Estudios de Cohortes , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/metabolismo , ARN Mensajero/metabolismo , Receptores de Hormona Liberadora de Corticotropina/genética , Receptores de Vasopresinas/genética , Receptores de Vasopresinas/metabolismoRESUMEN
Honey contains fructose in excess of glucose, which may lead to incomplete fructose absorption associated with abdominal symptoms and/or diarrhea. This hypothesis was investigated in 20 healthy volunteers (13 males, 7 females) with a mean (+/- SD) age of 35.9 +/- 12.1 y. Each subject drank the following aqueous solutions in random order: 20 g lactulose, 100 g honey, 50 g honey, and 35 g each of a glucose and fructose mixture. The breath-hydrogen concentration was measured every 15 min for 6 h. Semiquantitative estimates of carbohydrate malabsorption were assessed with lactose as a nonabsorbable standard. Breath-hydrogen concentrations increased by 52 +/- 6, 30 +/- 4, 20 +/- 3, and 4 +/- 1 ppm (mean +/- SEM) after each of the four test solutions, respectively. The estimated carbohydrate malabsorption was 10.3 +/- 1.8, 5.9 +/- 1.2, and 0.5 +/- 0.2 g after 100 g honey, 50 g honey, and the glucose-fructose mixture, respectively (F[2,57] = 16.05, P < 0.001). Within 10 h after the ingestion of 100 g honey, 50 g honey, and the glucose-fructose mixture, six, three and none of the volunteers, respectively, reported loose stools (chi 2 = 7.1, df = 2, P < 0.03). The results of this study suggest that carbohydrate malabsorption after ordinary doses of honey is frequent in healthy adults and may be associated with abdominal complaints. Honey may have a laxative effect in certain otherwise healthy individuals, probably because of incomplete fructose absorption.
Asunto(s)
Catárticos/farmacología , Diarrea/etiología , Carbohidratos de la Dieta/farmacología , Fructosa/farmacocinética , Miel/normas , Absorción , Administración Oral , Adulto , Análisis de Varianza , Pruebas Respiratorias , Diarrea/epidemiología , Femenino , Fructosa/administración & dosificación , Motilidad Gastrointestinal/efectos de los fármacos , Motilidad Gastrointestinal/fisiología , Glucosa/administración & dosificación , Glucosa/farmacocinética , Miel/análisis , Humanos , Hidrógeno/análisis , Incidencia , Lactulosa/administración & dosificación , Lactulosa/farmacocinética , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
The prevalence of lactose maldigestion in Greek adults is 75% but the age at which the lactase activity starts declining is not known. The prevalences of lactose maldigestion and intolerance were investigated in 150 randomly selected Greek children 5-12 y old by using breath-hydrogen analysis after ingestion of lactose (2 g/kg body wt, maximum 50 g) or 0.240 L of milk. Prevalence of lactose maldigestion increased with age (y = -7.30 + 6.49x, r = 0.88, P = 0.004), being 29.4% and 80.0% at ages 5 and 12 y, respectively. Before testing, the reported prevalences of milk-related symptoms by children with high and low lactose-digestion capacity were 21.1% and 39.7% (chi 2 = 5.96, P = 0.015), respectively. However, the corresponding prevalences of lactose intolerance after ingestion of milk were 7.3% and 8.6% (chi 2 = 0.1, P = 0.72) and only three children had a delta H2 greater than or equal to 20 ppm postprandially. Although intestinal lactase activity declines before age 5 y and many Greek children report milk-related symptoms, true malabsorption and intolerance of lactose after a glass of milk is rarely seen at this age.
Asunto(s)
Intolerancia a la Lactosa/epidemiología , Leche/efectos adversos , Factores de Edad , Animales , Pruebas Respiratorias , Niño , Grecia/epidemiología , Humanos , Intolerancia a la Lactosa/etiología , PrevalenciaRESUMEN
Th1 cytokines, such as interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), and Th1-inducing cytokines, such as IL-12, are involved in the pathogenesis of various organ-specific autoimmune diseases, including autoimmune diabetes. In this study, we investigated intracellular IFN-gamma release by T lymphocytes and IL-12 serum levels in 48 type 2 and 36 latent autoimmune diabetes of adults (LADA) diabetics and 25 control subjects in an attempt to evaluate their role in the pathogenesis of these clinical entities. Ionomycin (ION) and phorbol-12-myristate-13-acetate (PMA)-activated peripheral blood mononuclear cells (PBMCs) were stained with anti-CD4-FITC or anti-CD8-FITC and anti-IFN-gamma phycoerythrin (PE) monoclonal antibodies (mAbs) and analyzed by flow cytometry. IL-12 serum levels were determined by enzyme-linked immunosorbent assay (ELISA). In all study groups, IFN-gamma content of CD4(+) and CD8(+) lymphocytes was significantly upregulated by stimulation. Furthermore, it was observed that CD4(+) and CD8(+) lymphocytes from type 2 diabetics produced significantly lower levels of IFN-gamma compared with LADA patients and controls. However, the percentages of CD4(+)/IFN-gamma(+) and CD8(+)/IFN-gamma(+) cells from type 2 diabetics were significantly higher compared with controls. The flow cytometric picture of intracellular IFN-gamma release in LADA patients did not differ from that observed in controls. However, IL-12 serum levels in type 2 and LADA diabetics were lower than in controls. Because Th1 cytokines have been associated with the pathogenesis of autoimmune diabetes, these results preclude Th1 involvement in the autoimmune phenomena observed in LADA patients. In contrast, the low IFN-gamma levels observed in type 2 diabetics in combination with the low IL-12 serum levels might be a contributing factor in the frequently observed chronic complications in these patients.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 2/inmunología , Interferón gamma/biosíntesis , Interleucina-12/sangre , Células TH1/inmunología , Adulto , Biomarcadores/sangre , Linfocitos T CD4-Positivos/patología , Linfocitos T CD8-positivos/patología , Células Cultivadas , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/patología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/patología , Femenino , Humanos , Interleucina-12/inmunología , Masculino , Persona de Mediana Edad , Células TH1/patologíaRESUMEN
Inflammatory cytokines are soluble mediators of immune function that also regulate intermediate metabolism and several endocrine axes. To examine the effects of interleukin-6 (IL-6), the main circulating cytokine, on the hypothalamic-pituitary-testicular axis in men, we performed dose-response studies of recombinant human IL-6 (rHuIL-6) in normal volunteers. Increasing single doses of IL-6 (0.1, 0.3, 1.0, 3.0, and 10.0 microg/kg body weight) were injected subcutaneously into 15 healthy male volunteers (3 at each dose) in the morning. We measured the circulating levels of testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex hormone binding globulin (SHBG) at baseline and then at 24 h, 48 h, and 7 days after the IL-6 injection. LH and FSH levels were also measured half-hourly for the first 4 h after the IL-6 injection. All IL-6 doses were tolerated well and produced no significant adverse effects. Mean peak plasma IL-6 levels achieved after IL-6 administration were 8 +/- 1, 22 +/- 5, 65 +/- 22, 290 +/- 38, and 4050 +/- 149 pg/ml, respectively for the five doses. We observed no significant changes in plasma testosterone levels after the two smaller IL-6 doses. The three higher IL-6 doses, however, caused significant decreases in testosterone levels by 24 h, which persisted at 48 h and returned to baseline by 7 days. The higher testosterone suppression was after the 3.0 microg/kg dose, making the dose-response curve bell-shaped. There also appeared to be small but not significant increases in LH levels after the three higher IL-6 doses, which were not acute and seemed to follow temporally the testosterone decreases. The concurrent plasma levels of FSH and SHBG were not appreciably affected by any IL-6 dose. In conclusion, subcutaneous IL-6 administration, which caused acute elevations in circulating IL-6 levels of a similar magnitude to those observed in severe inflammatory and noninflammatory stress, induced prolonged suppression in testosterone levels in healthy men without apparent changes in gonadotropin levels. This suggests that IL-6 might induce persistent testicular resistance to LH action or suppression of Leydig cell steroidogenesis or both, with potential adverse effects on male reproductive function.
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Interleucina-6/uso terapéutico , Hipófisis/efectos de los fármacos , Testículo/efectos de los fármacos , Adulto , Relación Dosis-Respuesta a Droga , Hormona Folículo Estimulante/sangre , Humanos , Interleucina-6/efectos adversos , Hormona Luteinizante/sangre , Masculino , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Valores de Referencia , Globulina de Unión a Hormona Sexual/metabolismo , Testosterona/sangreRESUMEN
BACKGROUND: Strains of Helicobacter pylori with the cytotoxine-associated gene A (cagA) are linked to severe forms of gastroduodenal disease. Although eradication of H. pylori may predispose to the development of reflux esophagitis, the effects of CagA status on risk of esophagitis after successful H. pylori treatment are not known. METHODS: We studied 50 consecutive patients without esophagitis in whom H. pylori was eradicated successfully. CagA status was determined by immunoblotting sera from patients against H. pylori antigens. Patients underwent upper gastrointestinal endoscopy before eradication and 6, 12, 18, and 24 months after eradication or when reflux symptoms occurred. Biopsy specimens of the antrum and corpus were evaluated for gastritis before H. pylori eradication and at the end of the study. The sum of the scores for acute and chronic inflammation (both measured on a 0 [absent] to 3 [severe] scale) comprised the total gastritis severity score. RESULTS: In a multivariate proportional hazards regression analysis, positive CagA serology (hazard ratio [HR] = 10, 95% confidence interval [CI]: 1.3 to 81) and moderate-to-severe corpus gastritis (total severity score > or =4) before eradication (HR = 2.3, 95% CI: 1.2 to 6.1) were independent risk factors for the development of esophagitis after H. pylori eradication. CONCLUSION: Patients infected with strains of H. pylori that are cagA-positive are at increased risk of developing esophagitis after eradication of H. pylori.
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Proteínas Bacterianas/inmunología , Esofagitis/microbiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/patogenicidad , Adulto , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Gastritis/tratamiento farmacológico , Gastritis/microbiología , Gastritis/patología , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/patología , Helicobacter pylori/inmunología , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
OBJECTIVE: To evaluate and compare in vivo the protective efficacy of unilamellar liposomal amphotericin B (L-AmB) with that of deoxycholate amphotericin B (D-AmB) in experimental endocarditis. MATERIAL AND METHODS: In the rabbit model of experimental Aspergillus fumigatus endocarditis, two doses of each antifungal agent (1.5 mg/kg each) were administered intravenously at 4 hours and at 30 minutes before challenge with an inoculum of A. fumigatus. Three days later, the animals were sacrificed, and the aortic vegetations were analyzed. RESULTS: All 19 animals that did not receive chemoprophylaxis acquired endocarditis. In contrast, endocarditis developed in 2 of 10 animals pretreated with D-AmB (P < 0.01) and 3 of 8 animals pretreated with L-AmB (P < 0.01). Both D-AmB and L-AmB prevented the development of endocarditis due to A. fumigatus and decreased the concentration of fungi in the aortic vegetations by more than 1 log10. CONCLUSION: In the rabbit experimental model of Aspergillus endocarditis, D-AmB and L-AmB were equally effective in reducing the incidence of the infection and the tissue burden of fungi.
Asunto(s)
Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Aspergilosis/microbiología , Aspergilosis/prevención & control , Aspergillus fumigatus/efectos de los fármacos , Endocarditis/microbiología , Endocarditis/prevención & control , Anfotericina B/administración & dosificación , Animales , Antifúngicos/administración & dosificación , Colagogos y Coleréticos , Ácido Desoxicólico , Modelos Animales de Enfermedad , Técnicas In Vitro , Liposomas , Masculino , ConejosRESUMEN
BACKGROUND: There are no guidelines on second-line therapies for Helicobacter pylori eradication failures of omeprazole-clarithromycin-amoxicillin triple therapy. AIM: To compare the efficacy of two second-line therapies for persistent H. pylori infection. METHODS: Over a 6-year period, patients with persistent H. pylori infection following omeprazole-clarithromycin-amoxicillin eradication therapy were randomized to receive omeprazole, 20 mg twice daily, bismuth, 120 mg four times daily, metronidazole, 500 mg twice daily, and either tetracycline, 500 mg four times daily, or clarithromycin, 500 mg twice daily, given for 7 days. Before therapy, patients underwent endoscopy with biopsies for histology, culture and antibiotic susceptibility tests. H. pylori infection was confirmed by histology. RESULTS: Of the 95 randomized patients, 88 (93%) completed the study. Age, sex, smoking, ulcer/non-ulcer dyspepsia ratio and antibiotic resistance were not significantly different between the treatment groups. On intention-to-treat analysis, eradication was achieved in 41 of the 49 patients (84%; 95% confidence interval, 70.4-92.7%) and 27 of the 46 patients (59%; 95% confidence interval, 43.3-73.0%) of the tetracycline- and clarithromycin-containing groups, respectively (P=0.007). On multivariate regression analysis, the sensitivity of H. pylori to metronidazole had a likelihood ratio of 5.2 (P=0.022), followed by the type of quadruple therapy (likelihood ratio, 4.4; P=0.036). CONCLUSIONS: Tetracycline-containing quadruple rescue therapy is highly effective in treating H. pylori eradication failures of the omeprazole-amoxicillin-clarithromycin regimen.