Effect of icodextrin on heart rate variability in diabetic patients on peritoneal dialysis.

INTRODUCTION: Spectral analysis of heart rate variability is a noninvasive method for evaluating autonomic cardiovascular dysfunction under various clinical conditions, such as in dialysis patients, in whom an imbalance between the sympathetic and parasympathetic nervous system appears to be an important risk factor for sudden cardiovascular death and arrhythmia. ♢ OBJECTIVE: We compared the effect of icodextrin-based dialysis solution, an option that allows for better metabolic and fluid overload control, with that of glucose-based dialysis fluid on sympathetic and parasympathetic activity in the heart, as assessed by heart rate variability, in diabetic patients on peritoneal dialysis (PD). ♢ METHODS: This secondary analysis uses data from a randomized controlled trial in diabetic PD patients with high or high-average peritoneal transport using icodextrin-based (ICO group, n = 30) or glucose-based (GLU group, n = 29) solutions for the long dwell. All patients underwent 24-hour electrocardiographic Holter monitoring at baseline, and at 6 and 12 months of follow-up. ♢ RESULTS: We observed no significant differences between the groups in most of the variables analyzed, although values were, in general, below reference values. In the ICO group, total power and both low- and high-frequency power in normalized units increased, but the percentage of RR intervals with variation of more than 50 ms declined over time; in the GLU group, all those values declined. Plasma catecholamine levels were higher at baseline and declined over time. ♢ CONCLUSIONS: These results indicate a partial recovery of sympathetic activity in the ICO group, probably because of better extracellular fluid control and lower exposure to glucose with the use of icodextrin-based dialysis solutions.

Utilidad de las proteínas de pollo y de soja en ratas nutridas o desnutridas con diarrea inducida por lactosa / Utility of chicken and soybean protein in well-nourished or undernourished rats with lactose-induced diarrhea

En el tratamiento nutricional de la diarrea infantil se han utilizado con éxito preparaciones líquidas que contienen pollo combinado con cereales y/o tubérculos, que se preparan en la institución de hospitalización o en la casa. En un estudio anterior, se comparó la efectividad de fórmulas con proteínas de pollo o aislado de soja en el tratamiento de la diarrea infantil. El objetivo de este trabajo fue estudiar en ratas con o sin diarrea, la utilización de las proteínas y la disponibilidad de nutrientes de dietas preparadas con pollo o aislado proteico de soja, para determinar si los resultados obtenidos en los niños eran comparables a los obtenidos en ratas. Dado que la diarrea y la desnutrición frecuentemente están presentes de manera simultánea, también se estudiaron grupos de animales con o sin diarrea previamente desnutridos. Los resultados mostraron que durante la diarrea las ratas desnutridas fueron igualmente eficientes que las nutridas en utilizar los nutrientes presentes en las dietas con pollo o soja, por lo que no experimentaron un deterioro nutricional mayor que las nutridas. Adicionalmente, la severidad de la diarrea fue similar en las ratas asignadas a las dietas con pollo o soja. Asimismo, las ratas con diarrea consumieron, crecieron, absorbieron y retuvieron menos de los macronutrientes dietarios que las ratas control. Sin embargo, este efecto de la diarrea fue similar en las ratas que consumieron proteína de soja o de pollo. Como estos resultados coinciden con los obtenidos previamente en niños con diarrea aguda, se concluye que la proteína de soja es tan efectiva como la de pollo en el manejo nutricional de la diarrea y que la diarrea producida con lactosa en ratas es un modelo apropiado para el estudio de las consecuencias nutricionales de la misma.

In the nutritional treatment of diarrhea, good results have been obtained using liquid formulas with chicken meat together with cereals and/or starchy vegetables, prepared at home or at the clinic. In a previous study, formulas prepared with chicken meat or isolated soybean protein were tested in the treatment of infantile diarrhea. In order to determine if the results obtained in children could be reproduced in rats, the objective of the present study was to evaluate the effectiveness of the same diets in the nutritional treatment of well-nourished as well as undernourished rats with lactose induced diarrhea. The results showed that all the rats with diarrhea absorbed and retained less of the dietary nutrients and consequently, grew less than their counterparts without diarrhea. However, the absorption and retention measured in the nourished as well as in the undernourished rats were similar, indicating that a short period of malnutrition previous to the diarrhea episode, did not affect rats' absorption capacity. In addition, similarly to the results previously obtained in children, the rats with lactose induced diarrhea utilised equally well the dietary nutrients present in the chicken as well as in the soybean protein based diets. These results confirmed the value of isolated soybean protein in the nutritional treatment of diarrhea and showed that lactose induced diarrhea in rats is an appropriate model to study the nutritional consequences of diarrhea.

Papel del dominio V1/V2 de la glucoproteína 120 del virus de la inmunodeficiencia humana de tipo 1 en la inducción de anticuerpos neutralizantes / Role of the HIV-1 V1/V2 domains in the induction of neutralizing antibodies

El desarrollo de una vacuna preventiva contra el virus de la inmunodeficiencia humana de tipo 1 (VIH-1) es una de las mayores esperanzas para el control de la pandemia en los próximos años. Sin embargo, es claro que una de las mayores dificultades de una vacuna contra el virus es su alta tasa de mutación, lo que le permite evadir la respuesta inmune del húesped. La producción de anticuerpos neutralizantes (AcN) contra la envoltura vírica parece tener un papel importante en el control de la infección y en la ejecución de una protección eficaz luego de la inmunización. Diversos trabajos han mostrado que el dominio V1/V2 de la glucoproteína 120 del VIH-1 se encuentra involucrado en el tropismo vírico durante la infección, en el enmascaramiento de epítopes neutralizantes conservados, en los cambios conformacionales tras la unión a los correceptores y en la inducción de AcN. Sin embargo, hay pocos estudios enfocados sobre este dominio. Por otra parte, por ser uno de los dominios altamente glucosilados, numerosos estudios han determinado la influencia de los hidratos de carbono sobre la producción de AcN. Por tanto, la presente revisión está enfocada en la importancia de los AcN dirigidos contra epítopes de las regiones variables (principalmente V1/V2), su importancia en la protección contra la infección por el VIH-1, el papel que desempeñan esas regiones en la evasión de la respuesta inmune y, finalmente, se discute la importancia de los AcN en la búsqueda de una vacuna eficaz contra el virus (AU)

The development of a preventive vaccine against human immunodeficiency virus type-1 (HIV-1) provides hope for control of the pandemic over the coming years. Nevertheless, it is clear that one of the greatest difficulties in achieving this vaccine is the high mutation rate of the virus, which enables it to evade the host's immune response. The production of neutralizing antibodies (NAb) against the HIV-1 envelope proteins is believed to play an important role in controlling the infection and in providing effective protection following vaccination. Several studies have shown that the V1/V2 domain of the HIV-1 gp120 envelope protein is involved in viral tropism during infection, in masking conserved neutralizing epitopes, in the conformational changes occurring after coreceptor binding, and in NAb induction. Nonetheless, this domain has been poorly investigated. However, because the V1/V2 domain is highly glycosylated, numerous studies have determined the influence of carbohydrates on NAb production. The present review focuses on the importance of NAb directed against epitopes of the variable regions, mainly V1/V2, their importance in protecting against HIV-1 infection, and the role these regions play in evading the immune response. Lastly, we will discuss the importance of NAb in the search for an effective vaccine against HIV-1 (AU)

Conocimientos de los internos de medicina sobre el programa del diagnóstico prenatal de malformaciones congénitas / Knowledge medical internists have about antenatal diagnosis of congenital malformations

RESUMEN La mortalidad perinatal ha descendido a cifras difícilmente modificables. El diagnóstico de las malformaciones fetales se ha convertido en el "caballo de batalla" de la nueva obstetricia. Entrevistamos a 50 internos de medicina de un total de 124, con el objetivo de evaluar el nivel de conocimiento concluido su 6to año, sobre el diagnóstico prenatal de malformaciones congénitas, durante su rotación de gineco-obstetricia en el curso 2007-2008. Del total de estudiantes encuestados solo 19 respondieron correctamente el 50% de la encuesta y ninguno respondió el 100%. Existen dificultades con el nivel de conocimiento de los estudiantes de medicina sobre el valor interpretativo del ultrasonido de programa, las indicaciones de un ECO fetal y la importancia de la genética comunitaria. Por los resultados obtenidos en este trabajo recomendamos revisar y ampliar el programa docente de los internos y estudiantes de medicina, incluyendo conferencias, seminarios y actividades que respondan al contenido obstétrico, genético y comunitario necesarios para promover cada día mejores resultados en el desarrollo del programa materno infantil de la comunidad.

ABSTRACT Antenatal mortality has decreased to hardly modifiable figures. The diagnosis of fetal malformations has become into "the hobbyhorse" of the new obstetrics. To conduct this research paper 50 medical interns out of the total of 124 were interviewed to assess the level of knowledge they had about antenatal diagnosis of congenital malformations during their rotation in the specialty of gynecology when ending the 6th academic year 2007-2008 of the medical studies. Only 19 medical students, of the 50 interviewed, answered the questionnaire correctly in 50%, none of them answered it entirely. There were dificulties in the level of knowledge of the medical students when reading the results of the ultrasound, the indications of a fetal ecocardiography and the importance of the community genetics. Due to the results obtained in this research paper, it was recommended to revise and to extend the syllabus of the internists and medical students including lectures, seminars and activities which respond to the development of the maternal-child care program of the community.

Evaluación del conocimiento de Internos de Medicina sobre el programa de diagnóstico prenatal de malformaciones congénitas / Knowledge medical internists have about antenatal diagnosis of congenital malformations

La mortalidad perinatal ha descendido a cifras difícilmente modificables. El diagnóstico de las malformaciones fetales se ha convertido en el caballo de batalla de la nueva obstetricia. Entrevistamos a 50 internos de medicina de un total de 124, con el objetivo de evaluar el nivel de conocimiento concluido su 6to año, sobre el diagnóstico prenatal de malformaciones congénitas, durante su rotación de gineco-obstetricia en el curso 2007-2008. Del total de estudiantes encuestados solo 19 respondieron correctamente el 50 por ciento de la encuesta y ninguno respondió el 100 por ciento. Existen dificultades con el nivel de conocimiento de los estudiantes de medicina sobre el valor interpretativo del ultrasonido de programa, las indicaciones de un ECO fetal y la importancia de la genética comunitaria. Por los resultados obtenidos en este trabajo recomendamos revisar y ampliar el programa docente de los internos y estudiantes de medicina, incluyendo conferencias, seminarios y actividades que respondan al contenido obstétrico, genético y comunitario necesarios para promover cada día mejores resultados en el desarrollo del programa materno infantil de la comunidad...(AU)

Antenatal mortality has decreased to hardly modifiable figures. The diagnosis of fetal malformations has become into the hobbyhorse of the new obstetrics. To conduct this research paper 50 medical interns out of the total of 124 were interviewed to assess the level of knowledge they had about antenatal diagnosis of congenital malformations during their rotation in the specialty of gynecology when ending the 6th academic year 2007-2008 of the medical studies. Only 19 medical students, of the 50 interviewed, answered the questionnaire correctly in 50 per cent, none of them answered it entirely. There were dificulties in the level of knowledge of the medical students when reading the results of the ultrasound, the indications of a fetal ecocardiography and the importance of the community genetics. Due to the results obtained in this research paper, it was recommended to revise and to extend the syllabus of the internists and medical students including lectures, seminars and activities which respond to the development of the maternal-child care program of the community...(AU)

Icodextrin improves metabolic and fluid management in high and high-average transport diabetic patients.

BACKGROUND: Icodextrin-based solutions (ICO) have clinical and theoretical advantages over glucose-based solutions (GLU) in fluid and metabolic management of diabetic peritoneal dialysis (PD) patients; however, these advantages have not yet been tested in a randomized fashion. OBJECTIVE: To analyze the effects of ICO on metabolic and fluid control in high and high-average transport diabetic patients on continuous ambulatory PD (CAPD). PATIENTS AND METHODS: A 12-month, multicenter, open-label, randomized controlled trial was conducted to compare ICO (n = 30) versus GLU (n = 29) in diabetic CAPD patients with high-average and high peritoneal transport characteristics. The basic daily schedule was 3 x 2 L GLU (1.5%) and either 1 x 2 L ICO (7.5%) or 1 x 2 L GLU (2.5%) for the long-dwell exchange, with substitution of 2.5% or 4.25% for 1.5% GLU being allowed when clinically necessary. Variables related to metabolic and fluid control were measured each month. RESULTS: Groups were similar at baseline in all measured variables. More than 66% of the patients using GLU, but only 9% using ICO, needed prescriptions of higher glucose concentration solutions. Ultrafiltration (UF) was higher (198 +/- 101 mL/day, p < 0.05) in the ICO group than in the GLU group over time. Changes from baseline were more pronounced in the ICO group than in the GLU group for extracellular fluid volume (0.23 +/- 1.38 vs -1.0 +/- 1.48 L, p < 0.01) and blood pressure (systolic 1.5 +/- 24.0 vs -10.4 +/- 30.0 mmHg, p < 0.01; diastolic 1.5 +/- 13.5 vs -6.2 +/- 14.2 mmHg, p < 0.01). Compared to baseline, patients in the ICO group had better metabolic control than those in the GLU group: glucose absorption was more reduced (-17 +/- 44 vs -64 +/- 35 g/day) as were insulin needs (3.6 +/- 3.4 vs - 9.1 +/- 4.7 U/day, p < 0.01), fasting serum glucose (8.3 +/- 36.5 vs -37 +/- 25.8 mg/dL, p < 0.01), triglycerides (54.5 +/- 31.9 vs -54.7 +/- 39.9 mg/dL, p < 0.01), and glycated hemoglobin (0.79% +/- 0.79% vs -0.98% +/- 0.51%, p < 0.01). Patients in the ICO group had fewer adverse events related to fluid and glucose control than patients in the GLU group. CONCLUSION: Icodextrin represents a significant advantage in the management of high transport diabetic patients on PD, improving peritoneal UF and fluid control and reducing the burden of glucose overexposure, thereby facilitating metabolic control.

[Role of the HIV-1 gp120 V1/V2 domains in the induction of neutralizing antibodies]. / Papel del dominio V1/V2 de la glucoproteína 120 del virus de la inmunodeficiencia humana de tipo 1 en la inducción de anticuerpos neutralizantes.

The development of a preventive vaccine against human immunodeficiency virus type-1 (HIV-1) provides hope for control of the pandemic over the coming years. Nevertheless, it is clear that one of the greatest difficulties in achieving this vaccine is the high mutation rate of the virus, which enables it to evade the host's immune response. The production of neutralizing antibodies (NAb) against the HIV-1 envelope proteins is believed to play an important role in controlling the infection and in providing effective protection following vaccination. Several studies have shown that the V1/V2 domain of the HIV-1 gp120 envelope protein is involved in viral tropism during infection, in masking conserved neutralizing epitopes, in the conformational changes occurring after coreceptor binding, and in NAb induction. Nonetheless, this domain has been poorly investigated. However, because the V1/V2 domain is highly glycosylated, numerous studies have determined the influence of carbohydrates on NAb production. The present review focuses on the importance of NAb directed against epitopes of the variable regions, mainly V1/V2, their importance in protecting against HIV-1 infection, and the role these regions play in evading the immune response. Lastly, we will discuss the importance of NAb in the search for an effective vaccine against HIV-1.

Inflammation and extracellular volume expansion are related to sodium and water removal in patients on peritoneal dialysis.

BACKGROUND: Inflammation is an important risk for mortality in dialysis patients. Extracellular fluid volume (ECFv) expansion, a condition commonly seen in peritoneal dialysis (PD) patients, may be associated with inflammation. However, published support for this relationship is scarce. OBJECTIVES: To quantify the proportion of patients on PD with inflammation and to analyze the role of ECFv expansion and the factors related to these conditions. DESIGN: A prospective, multicenter cross-sectional study in six hospitals with a PD program. PATIENTS AND METHODS: Adult patients on PD were studied. Clinical data, body composition, and sodium and fluid intake were recorded. Biochemical analysis, C-reactive protein (CRP), and peritoneal and urinary fluid and sodium removal were also measured. RESULTS: CRP values positive (>or=3.0 mg/L) for inflammation were found in 147 (80.3%) and negative in 36 patients. Patients with positive CRP had higher ECFv/total body water (TBW) ratio (women 47.69 +/- 0.69 vs 47.36 +/- 0.65, men 43.15 +/- 1.14 vs 42.84 +/- 0.65; p < 0.05), higher serum glucose (125.09 +/- 81.90 vs 103.28 +/- 43.30 mg/dL, p < 0.03), and lower serum albumin (2.86 +/- 0.54 vs 3.17 +/- 0.38 g/dL, p < 0.001) levels. They also had lower ultrafiltration (1003 +/- 645 vs 1323 +/- 413 mL/day, p < 0.005) and total fluid removal (1260 +/- 648 vs 1648 +/- 496 mL/day, p < 0.001), and less peritoneal (15.59 +/- 162.14 vs 78.11 +/- 110.70 mEq/day, p < 0.01) and total sodium removal (42.06 +/- 142.49 vs 118.60 +/- 69.73 mEq/day, p < 0.001). In the multivariate analysis, only ECFv/TBW was significantly (p < 0.04) and independently associated with inflammation. ECFv/TBW was correlated with fluid removal (r = 0.16, p < 0.03) and renal sodium removal (r = 0.2, p < 0.01). CONCLUSION: The data suggest that ECFv expansion may have a significant role as an inflammatory stimulus. The results disclose a relationship between the two variables, ECFv expansion and inflammation, identified as independent risk factors for mortality in PD patients.

Inflammation in patients on peritoneal dialysis is associated with increased extracellular fluid volume.

BACKGROUND: Cardiovascular disorders (CD) are the most frequent cause of death in patients on dialysis. CD have been related to increased extracellular fluid volume, peritoneal transport type (PTT), hypertension, and inflammation. Inflammation is in itself a risk factor for mortality. The aim of this study was to assess the relationship of increased extracellular fluid volume, inflammation, and PTT in patients on continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). METHODS: A cross-sectional study was carried out with 20 healthy controls (C), 21 patients on CAPD, and nine patients on APD. Clinical and demographic variables were measured and registered. Peritoneal equilibrium test (PET) was done. Blood volume (BV), total body water (TBW), inferior vena cava diameter during inspiration (IVCDi) and expiration (IVCDe), serum albumin, and serum C-reactive protein (CRP) were measured. RESULTS: All patients on peritoneal dialysis (PD) had at least one sign or symptom of increased extracellular fluid volume, hypertension being the most common. Patients also had higher TBW (C, 60.7 +/- 7.2; APD, 62.6 +/- 8.7; CAPD, 66.1 +/- 8.3, as percentage of body weight, p <0.02), higher BV (C, 7.9 +/- 1.6; APD, 9.8 +/- 2.3; CAPD, 9.6 +/- 2.3, as percentage of body weight, p <0.02), higher DIVCi (C, 2.9 +/- 1.2; APD, 4.6 +/- 2.5; CAPD, 4.5 +/- 2.4 mm/m2 BSA, p <0.02), and higher DIVCe (C, 6.2 +/- 1.7; APD, 8.3 +/- 3.4; CAPD, 8.0 +/- 2.8 mm/m2 BSA, p <0.05). PD patients also had hypoalbuminemia and higher CRP levels. There was significant positive correlation between CRP and DIVCi (r=0.43, p <0.05) and IVCe (r=0.45, p <0.05) and between serum albumin and creatinine dialysate-to-plasma ratio (D/P Cr, r=0.57, p <0.01). Serum albumin and CRP were negatively correlated (r= -0.54, p <0.02). CONCLUSIONS: Patients on PD have increased extracellular fluid volume as compared with healthy controls. Hyperhydration is related to inflammation and to higher peritoneal transport types.

Comparación de tres técnicas de trazado retrógrado para la identificación del origen espinal del nervio ciático en ratón / Comparison of three neurotracing techniques for identification of the sciatic nerve spinal origen in mice

En el presente trabajo se compararon tres técnicas para la aplicación de dos tipos de trazadores retrógrados fluorescentes (Dil y Fluorogold), con el fin de identificar las neuronas motoras y sensoriales que contribuyen con fibras al nervio ciático en ratones adultos. Se ensayó la aplicación de cristales directamente en el nervio, la inyección intraneural y la impregnación del nervio seccionado usando una cámara de silicona. La localización específica de las neuronas motoras en la médula espinal y las neuronas sensoriales en los ganglios de la raíz dorsal que aportan al nervio ciático de ratón se logró aplicando el Fluorogold mediante una cámara en el cabo proximal de los nervios previamente seccionados. Al utilizar el trazador Dil, la misma técnica no permitió hacer la identificación específica de las neuronas. Se encontró que al nervio ciático de ratón podrían contribuir el ganglio de la raíz dorsal más rostrales que los informados para ratas. Estos resultados muestran que la metodología de aplicación de neurotrazadores en cápsula y la descalcificación de tejidos es útil para la localización de neuronas de ganglios de raíz dorsal y de la médula espinal que componen el nervio ciático de ratón adulto, lo que en el futuro permitir obtener mayor información sobre la neuroanatomía básica del ratón.

[Comparison of three neuro-tracing techniques for identification of the sciatic spinal nerve origin in mice]. / Comparación de tres técnicas de trazado retrógrado para la identificación del origen espinal del nervio ciático en ratón.

To identify sensory and motor neurons associated with the sciatic nerve in adult mice, three methods for applying fluorescent tracers (Fluorogold and Dil) were investigated: direct application, intraneural injection and impregnation of a sectioned nerve in a silicone chamber. Most accurate localization of the neurons on the dorsal root ganglia and spinal cord was accomplished by introducing the proximal stump of a transected sciatic nerve into a silicone chamber, filled with tracers and then decalcifying the tissue. Fluorogold was an effective tracing agent, in contrast to Dil, which was not. In addition to associations with cephalic ganglia L4, L5 and L6, as seen in rats, contributory neurons to the sciatic nerve were located in other ganglia in the mouse. These findings show that the silicone chamber-tissue decalcification technique is a viable tool for obtaining comparative neuroanatomical information in the mouse model.

Subpoblaciones neuronales presentes en el ganglio de la raíz dorsal / Neuronal subpopulations present in the dorsal root ganglion

La función principal de las neuronas del ganglio de la raíz dorsal (GRD) es transmitir la información sensorial desde la periferia hasta el sistema nervioso central. Dos clases de la célula están presentes en el ganglio: las células no neuronales y las neuronales. La heterogeneidad morfológica, fisiológica y bioquímica de la población neuronal permite diferenciarla en subpoblaciones. Morfológicamente, se distinguen tres tipos neuronales (A, B y C) según el tamaño y las características ulraestructurales. Fisiológicamente, hay una relación directa entre el tamaño, el diámetro de las fibras nerviosas y la velocidad con que conducen el impulso nervioso. Finalmente, el uso de marcadores (neuropéptidos, enzimas, receptores, etc.) permite realizar una clasificación bioquímica, que es la más utilizada para estudiar la función neuronal. Este artículo revisa la evidencia experimental sobre el tema de la heterogeneidad neural del GRD y presenta una correlación desde el punto de vista bioquímico y fisiológico en los casos en donde hay información disponible. El estudio de subpoblaciones en este ganglio resulta de bastante interés para investigaciones en neurociencias principalmente en infecciones por virus neurotrópicos, traumatismos del nervio periférico y el estudio de factores neurotróficos, entre otros

Evaluación de una técnica capilar modificada para inmunocitoquímica en cultivos adheridos a cubreobjetos de vidrio / Evaluation of a modified capillary technique for immunocytochemistry of coverslip adhered cultures

Con el objeto de evaluar una técnica inmunocitoquímica para cultivos celulares adheridos a cubreobjetos, se ensayó una modificación de la técnica capilar comparándola con la técnica convencional (en cajas de 24 pozos). Cultivos de ganglio de raíz dorsal de raton adulto se sometieron a inmunodetección por peroxidasa e inmunofluorescencia de neurofilamento, proteína S-100 y virus de la rabia; la especificidad e intensidad de la marca con una u otra técnica no cambió. El uso de la técnica capilar modificada significó un ahorro de 92 por ciento en los volúmenes de anticuerpos y reactivos usados, sin sacrificar los patrones de marca, sin incrementar el tiempo del procedimiento y usando materiales que corrientemente se encuentran en cualquier laboratorio