María Susana Feliu

Potential markers of the nutritional status in an experimental model.

The activity of adenine deaminase (ADA) and purine nucleoside phosphorylase (PNP) as potential nutritional markers was analyzed in an experimental model. Weanling Wistar rats were fed a protein-free diet ad libitum to obtain a severe degree of wasting. An age-matched control group received a stock diet. At the end of the experiment, body weight (BW) and thymus weight (TW) were determined. Activity of ADA and PNP was determined on thymocytes of protein-deprived and control rats; the results, expressed as micromoles of uric acid x 10(-1)/W (W = TW/BW(0.75)), were 17.0 +/- 2.6 versus 9.1 +/- 3.0 for ADA and 11.5 +/- 4.2 versus 3.9 +/- 1.0 for PNP (P < 0.01). These results suggest that the nutritional stress provoked by the administration of a protein-free diet from weaning onward affects the development of thymocytes. Moreover, the increase in the activity of ADA and PNP would be an alternative mechanism to avoid the accumulation of high levels of deoxynucleotides, which would be toxic for T lymphocytes. However, some investigators have observed an increase of ADA activity in human serum under some adverse conditions; for this reason and taking into account the present findings, it would be interesting to determine the relation between the activity of ADA and PNP in thymocytes and serum in experimental models to analyze and propose these biochemical parameters as potential and useful markers of nutritional status; it also would be interesting to test this relation in human studies.

Inflammatory biomarker profile in children with cystic fibrosis: preliminary study

The aim of this preliminary study was to determine specific proteins, related to inflammation process and nutritional status as well as to total antioxidant capacity, in children suffering from cystic fibrosis (CF). The study was performed on 17 nonhospitalized children (12 boys and 5 girls) with CF aged 3 months to 10 years, who were assisted at the Nutrition Service from Pedro de Elizalde Hospital. Transferrin, transthyretin, ceruloplasmin (Cp), haptoglobin, C-reactive protein (CRP) and fibrinogen were measured by single radial immunodiffusion techniques. Total antioxidant capacity (TAC) was determined by a decolorization assay. Statistical analyses were performed by the Students t test. Transferrin and transthyretin values were lower in CF patients in comparison with data obtained from healthy children (reference group, RG). The decreased transferrin concentration and the tendency towards low plasma transthyretin values suggested an abnormal nutritional status. However, higher Cp and haptoglobin levels were shown in patients than in RG. The fact that 23 and 50% of patients exceeded the desirable values for fibrinogen (<285.0 mg/dl) and CRP (<0.2 mg/dl), respectively, should be highlighted. The TAC (mM; Trolox equivalents) was shown to be lower in the CF group than in RG. The diminished TAC concomitant with an increased plasma Cp concentration would exacerbate the inflammatory status and could explain the depression of the immune system. These preliminary results could explain the need to include biochemical and functional parameters in the early nutritional status evaluation in CF patients in order to use appropriate nutritional and pharmacological therapies and consequently to improve their survival and quality of life.

Nutritional Status and Lipid Profile in HIV-Infected Adults.

In the last decades, there have been many reports of HIV infection and abnormalities in lipid metabolism and cardiovascular disease (CVD). This study aims at describing the nutritional status of HIV-infected adults and its relation to lipid profile through traditional [total cholesterol (TC), HDL cholesterol (HDL), triglycerides (TG), non-HDL cholesterol and LDL cholesterol (LDL)] and other parameters [Apolipoprotein B (ApoB), fibrinogen, and high sensitive-C-reactive protein (hs-CRP)]. A cross-sectional descriptive study was performed. Body mass index (BMI) was calculated and references were taken from WHO. TC, HDL, TG and glucose were determined and non-HDL cholesterol and LDL were calculated. ApoB and fibrinogen were determined by quantitative radial immunodiffusion on agar plates (Diffuplate,Biocientífica SA,Argentina) and hs-CRP by immunoturbidimetric test. Qualitative variables were compared with the Chi-square test or Fishers exact test. Quantitative variables were compared applying parametrics or nonparametric tests. Pearson test for correlations. Software SPSS 17.0. 97 patients were analyzed: 69.1% were men. 80% were on antiretroviral treatment. Average (SD) BMI was 24.3 (4.1) kg/m(2). 29.4% were overweight and 5.9% obese. Patients with a BMI ≥25.0 kg/m(2) presented significantly higher levels of TG, ApoB and glycemia than well-nourished people [246.1(169.0) vs. 142.9(78.4) mg/dL;p=0.029, 198.6(69.3) vs. 126.4(50.6) mg/dL;p=0.01 and 100 (3.2) vs. 90.2 (6.9) mg/dL;p=0.008 resp.] and a significantly decreased HDL [37.2(1.5) vs. 49.8(10.4) mg/dL;p<0.01]. No statistically significant correlation was found between ApoB and non-HDL (p=0,063). There was no evidence that there is a direct relation between Apo B and the other lipid parameters. The potential increase in CVD in this group of patients, would be related to the higher levels of TG, ApoB and overweight/obesity. Nutritional education is needed to promote a healthy weight to warn against the risk of cardiovascular disease.

Protein feeding and the activity of adenosine deaminase and purine nucleoside phosphorylase in rat thymus

Abstract It is known that the thymus is severely affected by nutritional deficiency. Adenosine deaminase (ADA) and Purine Nucleoside Phosphorilase (PNP) are thought to be important for normal lymphocyte development. The present paper studies the effect provoked on the activity of these thymic enzymes in growing rats by marginal(PF15), moderate(PF20) and severe(PF25) protein deprivation and the subsequent oral administration of a 20% dietary protein during 9 days (R). Results were expressed as μmol uric acid x 10 −1 /W, per five minutes, where W=Tw (mg)/Bw(g) 0.75 . (Mean ± S.D.). Statistical differences between PF15 and Control (C) in: ADA (17.5±4.1 vs. 10.5±2.8), PNP (7.1±0.8 vs. 3.7±0.9); PF20 and C in:, ADA (15.7±4.5 vs. 9.1±3.0), PNP (10.3±4.1 vs. 3.9±1.0); PF25 and C in: ADA (17.0±2.6 vs. 9.1±3.0) and PNP (11.5±4.2 vs. 3.9±1.0) were observed (p

Specific Nutritional Supplement (Supportan ® ) in the Supportive Care of the Radio-Chemotherapy Treatment of Head and Neck Cancers: Biochemical Parameters. Preliminary Study

BACKGROUND This is a preliminary study of a specific nutritional supplement -Supportan(®) - for the clinical support of patients with locally advanced head and neck (H&N) cancers who underwent treatment with concurrent radiochemotherapy (RT-CHT). MATERIAL AND METHODS Seven patients received nutritional supplement (Supportan(®)) plus habitual diet during a median time of treatment with RT on 7.8 weeks plus concurrent weekly CHT(S). Specific serum protein fractions as a potential useful tool to evaluate the nutritional status were determined. The main objective was to assess the compliance with the above-mentioned treatment. RESULTS Patients completed the nutritional support, 5 / 7 patients via oral route and 2/7 patients through nasogastric tube. All studied patients, that completed treatment, had not severe mucositis -ulcera, hemrraghe and/ or infection. None of them had another severe toxicity by treatment nor had impairment of Pefomance Status. No differences in all specific sera proteins were observed between S and To. CONCLUSION In this preliminary study of few patients, we have observed a potential usefulness of Supportan(®) in the compliance of concurrent RT-CHT in patients with H&N cancers; moreover, its administration was useful to maintain the initial biochemical nutritional profile.

Dietas con diferentes fuentes lipídicas: su efecto en el perfil de ácidos grasos séricos de la rata

El perfil de lipidos de una dieta es importante para prevenir enfermedades cronicas y mejorar la calidad de vida de los individuos. Objetivo: estudiar el efecto de dietas con diferentes fuentes y concentraciones lipidicas sobre el perfil de acidos grasos en suero de ratas en periodo de crecimiento activo. Las dietas experimentales, contenian 15 y 40 Kcal% de lipidos aportados por: manteca (M); aceite de oliva (O); aceite de girasol alto oleico (AO) y aceite de girasol (G). El control recibio dieta normocalorica (fuente lipidica: aceite de soja). Los grupos M, O y AO presentaron un aumento en los niveles sericos del acido oleico, con disminucion de los acidos grasos esenciales (AGE) con respecto al grupo C. Estos resultados se observan independientemente del F% de la dieta. El grupo G muestra aumento de acido linoleico solo cuando el F% de la dieta fue 40. La administracion de estas dietas provoco cambios en el perfil de acidos grasos en suero en respuesta a las diferentes fuentes aportadas por las dietas, solo algunos cambios observados en el grupo G fueron tambien en respuesta al alto porcentaje de grasa

Effects of high-fat diets from different sources on serum and thymus lipid profile: study in an experimental model.

BACKGROUND A balanced diet is important to maintain an optimal health status and to prevent noncommunicable chronic diseases. The principal objective of this study was to analyze the effect of diets containing high fat levels from different sources, on serum and thymus lipid profile, in adult rats. METHODS Experimental diets contained 50% kcal of fat, provided by butter (B) or sunflower oil (S); control diet (C) was isocaloric, with 15 kcal of fat per 100 total kcal, provided by soy oil. Diets were otherwise complete in all nutrients and were administered for 40 days. RESULTS Group B had higher levels of total cholesterol and triglycerides than C; S serum lipid profile did not differ from C, despite the higher fat content. Regarding serum and thymus FA profile, B showed an increase of saturated fatty acids and lower levels of ω6 and ω3 FA, and S had lower levels of ω3 fatty acids. CONCLUSIONS The administration of high-fat diets, during 40 days to adult rats, provoked specific variations on serum and thymus fatty acids, as a consequence of differences in FA profile of their lipid sources. These results reflect the impact that eating habits have on health status. It is important to put emphasis not only on the reduction of total fat intake, but also on choosing healthy sources of fat, replacing saturated fatty acids by polyunsaturated and including oils with higher content of ω3 to keep a balanced ω6/ω3 ratio.

ADENOSINA DEAMINASA: SU RESPUESTA ANTE DESEQUILIBRIOS NUTRICIONALES

Se ha demostrado que el estres nutricional provoca incremento en la actividad de adenosina deaminasa en timo de rata y ademas aumenta su actividad en el suero y otros fluidos biologicos de pacientes inmunocompro-metidos. En este estudio se analizo si la determinacion de la actividad de ADA en suero podria considerarse parametro bioquimico funcional en el seguimiento de poblaciones en riesgo nutricional. Se estudiaron mujeres con anorexia nerviosa (AN, 14-32 anos) y ninos obesos de ambos sexos (O, 5-13 anos). La actividad de ADA se determino por el metodo de Giusti y Galante. Los resultados se compararon con controles de igual edad. Los resultados (X±DE (UI/L)) fueron AN: 25.7±8.2* vs. 21.0±4.6 y O: 27.1±9.1*vs. 23.0±5.6 (*p<0.02). Estos hallazgos, avalarian la hipotesis surgida de estudios previos, de proponer la determinacion de la actividad serica de ADA, como un indicador funcional relacionado con los mecanismos de defensa en los estudios de nutricion

Activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) on undernourished and renourished rats' thymus.

We studied the effect of administration of a low quality dietary protein, from weaning onwards, on the thymus of undernourished rats and the posterior effect of refeeding with a high quality dietary protein. Changes in thymus weight and the activity of Adenosine Deaminase (ADA) and Purine Nucleoside Phosphorylase (PNP) on thymus, were determined. Wistar rats were suckled in groups of 14-16 per dam since birth to weaning (23 days) to obtain undernutrition. At weaning, a group of 14-16 rats received pre-cooked maize flour (Protein content: 6.5%) for 18 days. One group was sacrificed (M) and the other rats were refed with the casein diet (Protein content: 20%) during 20 days (R). The age-matched control groups were fed stock diet since 40 (C40) and 60 (C60) days of age, respectively. At the end of the experimental period, body (Bw) and thymus weight were determined. ADA and PNP activities were determined in thymocyte suspensions. Highly significant differences in thymus weight-expressed as mg or mg/Bw(0.75)-and the activity of ADA and PNP were observed in rats fed the experimental diet containing maize flour, when compared to the respective age-matched control. No statistical differences were observed between R and C60.The administration of a high quality dietary protein to undernourished weanling rats is capable to reverse the damage produced by the low quality dietary protein on thymus weight and ADA and PNP thymus activities.