Electrochemical and AFM characterization on gold and carbon electrodes of a high redox potential laccase from Fusarium proliferatum.

The redox potential of the T1 copper site of laccase from Fusarium proliferatum was determined by titration to be about 510 mV vs. SCE (750 mV vs. NHE), which makes it a high redox potential enzyme. Anaerobic electron transfer reactions between laccase and carbon and gold electrodes were detected, both in solution and when the enzyme was adsorbed on these surfaces. In solution, a single high-potential signal (660 mV vs. SCE) was recorded at the carbon surfaces, attributable to the T1 copper site of the enzyme. However, a well-defined oxidative process at about 660 mV and an anodic wave at 350 mV vs. SCE were recorded at the gold electrode, respectively associated with the T1 and T2 copper sites. Laccase-modified carbon electrodes behaved analogously when the enzyme was in solution, unlike laccase adsorbed on gold, which showed only a low-potential signal. Laccase molecules were successfully imaged by AFM; obtaining a thick compact stable film on Au(111), and large aggregates forming a complex network of small branches leaving voids on the HOPG surface. Laccase-modified carbon electrodes retained significant enzymatic activity, efficiently oxidising violuric acid and reducing molecular oxygen. Explanations are proposed for how protein-film organisation affects the electrode function.

[Can FT3 levels facilitate the detection of inflammation or catabolism and malnutrition in dialysis patients?]. / ¿Pueden los niveles de T3L facilitar la detección de estados inflamatorios o de catabolismo y desnutrición en enfermos en diálisis?

INTRODUCTION: Low serum free triiodothyronine (FT3) levels have been reported in a high percentage of chronic renal failure (CRF) patients and have been considered as independent predictors of mortality in both hemodialysis (HD) and peritoneal dialysis (PD). A reduction in thyroid function in dialysis patients could be a marker of malnutrition and/or inflammation. OBJECTIVE: Our aim has been to evaluate the incidence of low T3 syndrome in a group of dialysis patients and analyze its relationship with different parameters of malnutrition and inflammation. PATIENTS AND METHODS We included 32 stable dialysis patients (24 HD and 8 DP); mean age +/- SD 71.2 +/- 11.7 years; 46.9% males; 15.6% diabetics; mean time on dialysis 47 +/- 43 months. The following parameters were measured in every patient: thyrothropin (TSH), Free T4 (FT4) and Free T3 (FT3); biochemical data related to nutritional status; anthropometric measurements, bioelectrical impedance vector analysis (BIVA), and dietary survey of three consecutive days. Statistical analysis was performed by using SPSS 11.0. RESULTS: Mean hormonal values of thyroid function were: TSH 2,2 +/- 1.5 U/ml (range: 0,4-5.0); FT4 14.7 +/- 2.3 pmol/l (range: 11.0-23.0) and FT3 4,0 +/- 0.71 pmol/l (range: 3.95-6.80). Only 2 patients (6.3%) showed low FT4 levels and another 2 patients increased TSH levels, whereas 17 patients (53.1%) presented with low FT3 levels. We did not found any correlation between serum FT3, FT4 and TSH levels. We found a correlation between FT3 and inflammation/nutritional parameters: prealbumin (r = 0,36; p = 0,04); transferrin (r = 0,40; p = 0,025); PCR (r = -0.38; p = 0,039); and IGF-I (r = 0,38; p = 0,03); body mass index (BMI) (r = 0,51; p = 0,002); arm circumference (AC) (r = 0,65; p = 0,000), and arm muscle circumference (AMC) (r = 0,72; p = 0,000). FT3 levels were also correlated with BIVA parameters: phase angle (r = 0,54; p = 0,002); muscle mass percentage (r = 0,49; p = 0,005); and cell mass percentage (r = 0,53; p = 0,02), but not with any data of fat mass. AMC was the only variable that independently correlated with FT3 levels in the multivariate regression analysis (r = 0,69; r2: 0,48; p = 0,000) CONCLUSION: Half of our dialysis patients have decreased levels of serum FT3 without alteration on FT4 or TSH. Low FT3 levels are correlated bioquimical and anthropometric parameters indicators of malnutrition and inflammation. Periodical measurement of FT3 levels could be used by clinicians as an accesible and reproducible method to detect such states.

Can FT3 levels facilitate the detection of inflammation or catabolism and malnutrition in dialysis patients?

Introduction: Low serum free triiodothyronine (FT3) levels have been reported in a high percentage of chronic renal failure (CRF) patients and have been considered as independent predictors of mortality in both haemodialysis (HD) and peritoneal dialysis (PD). A reduction in thyroid function in dialysis patients could be a marker of malnutrition and/or inflammation. Objective: Our aim has been to evaluate the incidence of low T3 syndrome in a group of dialysis patients and analyze its relationship with different parameters of malnutrition and inflammation. Patients and Methods: We included 32 stable dialysis patients (24 HD and 8 DP); mean age ± SD 71.2 ± 11.7 years; 46.9% males; 15.6% diabetics; mean time on dialysis 47 ± 43 months. The following parameters were measured in every patient: thyrothropin (TSH), Free T4 (FT4) and Free T3 (FT3); biochemical data related to nutritional status; anthropometric measurements, bioelectrical impedance vector analysis (BIVA), and dietary survey of three consecutive days. Statistical analysis was performed by using SPSS 11.0. Results: Mean hormonal values of thyroid function were: TSH 2,2 ± 1.5 U/ml (range: 0,4-5.0); FT4 14.7 ± 2.3 pmol/l (range: 11.0-23.0) and FT3 4,0±0.71 pmol/l (range: 3.95-6.80). Only 2 patients (6.3%) showed low FT4 levels and another 2 patients increased TSH levels, whereas 17 patients (53.1%) presented with low FT3 levels. We did not found any correlation between serum FT3, FT4 and TSH levels. We found a correlation between FT3 and inflammation/nutritional parameters: prealbumin (r = 0,36; p = 0,04); transferrin (r = 0,40; p = 0,025); PCR (r = -0.38; p = 0,039); and IGF-I (r = 0,38; p = 0,03); body mass index (BMI) (r = 0,51; p = 0,002); arm circumference (AC) (r = 0,65; p = 0,000), and arm muscle circumference (AMC) (r = 0,72; p = 0,000). FT3 levels were also correlated with BIVA parameters: phase angle (r = 0,54; p = 0,002); muscle mass percentage (r = 0,49; p = 0,005); and cell mass percentage (r = 0,53; p = 0,02), but not with any data of fat mass. AMC was the only variable that independently correlated with FT3 levels in the multivariate regression analysis (r = 0,69; r2: 0,48; p = 0,000). Conclusion: Half of our dialysis patientshave decreased levels of serum FT3 without alteration on FT4 or TSH. Low FT3 levels are correlated bioquimical and anthropometric parameters indicators of malnutrition and inflammation. Periodical measurement of FT3 levels could be used by clinicians as an accessible and reproducible method to detect such states (AU)

Introducción: Un alto porcentaje de pacientes en diálisis presenta niveles séricos disminuidos de triiodotironina libre (T3L), y algunos autores han mostrado su relación con marcadores de inflamación. Niveles bajos de T3L también se han mostrado como predictores independientes de mortalidad en diálisis. Objetivo: Evaluar la incidencia de síndrome T3L baja en un grupo de pacientes en diálisis y analizar su relación con diferentes parámetros de malnutrición e inflamación. Pacientes y métodos: Se estudiaron 32 pacientes estables en diálisis (24 hemodiálisis y 8 diálisis peritoneal), edad (media ± DS) 71,2 ± 11,7 años; 46,9% varones; 15,6% diabéticos; media de tiempo en diálisis 47 ± 43 meses. En cada paciente se cuantificó: tirotropina, T4 Libre y T3L; parámetros bioquímicos relacionados con nutrición e inflamación; parámetros antropométricos, composición corporal mediante bioimpedancia eléctrica con análisis vectorial e ingesta de nutrientes. El análisis estadístico se hizo usando un SPSS 11.0. Resultados: La media de los valores de las hormonas tiroideas fue: TSH 2,2 ± 1,5 U/ml (rango 0,4-5,0), T4L 14,7 ± 2,3 pmol/l (rango: 11,0-23,0) y T3L 4,0 ± 0,71 pmol/l (rango: 3,95-6,80). Sólo dos pacientes (6,3%) mostraron niveles de T4L bajos, y otros dos pacientes aumento de TSH, mientras que 17 pacientes (53,1%) presentaron niveles bajos de T3L. No encontramos ninguna correlación entre los niveles de T3L, T4L y TSH. Los niveles de T3L se correlacionaron con parámetros de inflamación/ nutrición: prealbúmina (r = 0,36; p = 0,04); transferrina (r = 0,40; p = 0,025); proteína C reactiva (r = - 0,38; p = 0,039); y factor de crecimiento similar a la insulina (r = 0,38; p = 0,03); índice de masa corporal (r = 0,51; p = 0,002); circunferencia de brazo (r = 0,65; p = 0,000); perímetro muscular de brazo (r = 0,72; p = 0,000), ángulo de fase (r = 0,57; p = 0,001); porcentaje de masa muscular (r = 0,49; p = 0,005) y porcentaje de masa celular (r = 0,54; p = 0,002). En el análisis de regresión lineal múltiple, el perímetro muscular del brazo fue la única variable que mostró asociación independiente con los niveles de T3L (r = 0,69; p = 0,000). Conclusión: Alrededor del 50% de los pacientes en diálisis tienen niveles séricos disminuidos de T3L sin alteración de TSH o T4L. Estos niveles se correlacionan con parámetros de malnutrición e inflamación. Su determinación periódica podría facilitar al clínico un método accesible y reproducible de detección de estos estados (AU)

Consumo de calcio por la mujer española de entre 45 y 65 años / Calcium intake in Spanish women aged between 45 and 65 years old

Objetivo: Conocer si la dieta actual de la mujer española aporta la cantidad de calcio necesaria para prevenir la osteoporosis y si los suplementos de calcio son empleados por los ginecólogos como profilaxis y/o tratamiento de la osteopenia/osteoporosis. Para ello, se estudiaron mujeres de una zona costera (Valencia) y una zona del interior (Madrid). Material y método: Estudio abierto de 250 mujeres posmenopáusicas para conocer el consumo de calcio en su dieta y en el que 88 ginecólogos opinan sobre el consumo de calcio en la dieta de las mujeres posmenopáusicas, y el empleo de suplementos de calcio en la prevención y/o tratamiento de la osteoporosis. Resultados: El 73% de los médicos encuestados opina que las mujeres de edades comprendidas entre 45 y 65 años no consumen en su dieta la cantidad de calcio necesaria para prevenir la osteoporosis. Sólo el 51% de los ginecólogos prescribe calcio de forma profiláctica, mientras que el 85% emplea suplementos de calcio junto con fármacos antirresortivos o agentes de formación ósea en el tratamiento de la osteopenia/osteoporosis. El 70% no deriva a las mujeres al reumatólogo y el 67% de los médicos incluye la densitometría en el protocolo de la mujer menopáusica. Conclusiones: Los ginecólogos opinan que las mujeres españolas de las zonas estudiadas con edades entre 45 y 65 años no consumen en su dieta la cantidad de calcio necesaria para prevenir la osteoporosis. Un 50% prescribe calcio de forma profiláctica a las mujeres en edades comprendidas entre 45 y 65 años, al no haber acuerdo en si un aporte suplementario de calcio en la dieta es una medida terapéutica que puede lograr una remisión del deterioro óseo. De forma mayoritaria el calcio acompaña a cualquier fármaco antirresortivo. La opinión más generalizada es que el calcio inhibe la resorción ósea y que, consecuentemente, puede ser de utilidad en el tratamiento de las enfermedades óseas que cursan con mayor resorción como sucede con la osteoporosis posmenopáusica

Objective: To determine whether the current diet of Spanish women provides adequate calcium intake to prevent osteoporosis and whether calcium supplements are used by gynecologists as prophylaxis and/or treatment of osteopenia/osteoporosis. Women living in a coastal region (Valencia) and an interior region (Madrid) were studied. Material and method: We performed an open study in 250 postmenopausal women to determine dietary calcium intake. Eighty-eight gynecologists were surveyed to determine their opinion of dietary calcium intake and the use of calcium supplements in osteoporosis prevention and/or treatment. Results: Seventy-three percent of the gynecologists surveyed believed calcium intake in women aged between 45 and 65 years old was insufficient to prevent osteoporosis. Only 51% prescribed calcium for prophylaxis while 85% used calcium supplements together with antiresorptive drugs and bone-forming agents in the treatment of osteopenia/osteoporosis. Seventy percent did not refer women to rheumatology clinics and 67% included densitometry in the protocol of menopausal women. Conclusions: Gynecologists believe that dietary calcium intake in Spanish women aged 45-65 years old and living in the areas studied was insufficient to prevent osteoporosis. Consensus is lacking on whether dietary calcium supplements can produce remission of bone loss; 50% prescribed calcium as prophylaxis in women in this age group. Calcium supplementation was usually accompanied by an antiresorptive drug. The most widespread opinion was that calcium inhibits bone resorption and consequently that it can be useful in the treatment of bone diseases causing substantial resorption such as postmenopausal osteoporosis