Gilberto João Padovan

Atrophic Cardiac Remodeling Induced by Taurine Deficiency in Wistar Rats

Introduction Micronutrient deficiency is observed in heart failure patients. Taurine, for example, represents 50% of total free amino acids in the heart, and in vivo studies have linked taurine deficiency with cardiomyopathy. Methods Thirty-four male Wistar rats (body weight = 100 g) were weighed and randomly assigned to one of two groups: Control (C) or taurine-deficient (T (-)). Beta-alanine at a concentration of 3% was added to the animals’ water to induce taurine deficiency in the T (-) group. On day 30, the rats were individually submitted to echocardiography; morphometrical and histopathological evaluation and metalloproteinase activity, oxidative stress and inflammation evaluation were performed. Tissue samples were collected to determine the taurine concentration in the heart. Results Taurine deficiency led to decreases in: ventricular wall thickness, left ventricle dry weight, myocyte sectional area, left ventricle posterior wall thickness and ventricular geometry. With regard to heart function, the velocity of the A wave, the ratio between the E and A wave, the ejection fraction, fractional shortening and cardiac output values were decreased in T (-) rats, suggesting abnormal diastolic and systolic function. Increased fibrosis, inflammation and increased activation of metalloproteinases were not observed. Oxidative stress was increased in deficient animals. Conclusions These data suggest that taurine deficiency promotes structural and functional cardiac alterations with unique characteristics.

Metabolic parameters of postmenopausal women after quinoa or corn flakes intake - a prospective and double-blind study

Abstract A prospective and double-blind study was conducted on 35 women with weight excess who consumed 25 grams of quinoa flakes (QF) or corn flakes (CF) daily during a period of four consecutive weeks. At the beginning (T1) and at the end (T2) of the intervention, total calorie intake was evaluated, anthropometric assessment was performed, blood was collected for the determination of glucose, total cholesterol and fractions, oxidative stress markers, vitamin E and enterolignans. Significant reductions were detected in serum triglyceride (CF group = 133.9 ± 89.4 to 113.7 ± 57 mg/dl and QF group = 112.3 ± 35 to 107.9 ± 33.1 mg/dl), TBARS (CF group = 3.2 ± 0.8 to 2.9 ± 0.5 µmol/l and QF group = 3.06 ± 0.6 to 2.89 ± 0.5 µmol/l) and vitamin E concentrations (CF group = 19.5 ± 5 to 17.9 ± 4 µM and QF group = 17.9 ± 4 to 16.9 ± 3 µM) and an increase in urinary excretion of enterolignans (CF group = 2.05 ± 1.3 to 2.24 ± 1.4 nm/ml and QF group = 2.9 ± 1.6 to 3.2 ± 2.7 nm/l), in both study groups. The reduction of total cholesterol (191 ± 35 to 181 ± 28 mg/dl) and LDL-cholesterol (LDL-c) (129 ± 35 to 121 ± 26 mg/dl), and the increase in GSH (1.78 ± 0.4 to 1.91 ± 0.4 µmol/l) occurred only in the QF group, showing a possible beneficial effect of QF intake.

Altered plasma response to zinc and iron tolerance test after Roux-en-Y gastric bypass

BACKGROUND The duodenum and proximal jejunum are excluded after Roux-en-Y gastric bypass but these intestinal sites are where iron and zinc are most absorbed. Therefore, they are among the nutrients whose digestive and absorptive process can be impaired after surgery. The aim of the present study was to investigate the iron and zinc plasma response to a tolerance test before and after bariatric surgery. The study was performed at São Paulo University School of Medicine of Ribeirão Preto, Brazil. METHODS In a longitudinal paired study, 9 morbidly obese women (body mass index ≥40 kg/m(2)) underwent an iron and zinc tolerance test before and 3 months after surgery. The iron and zinc levels were determined at 0, 1, 2, 3, and 4 hours after a physiologic unique oral dose. The mineral concentrations in the plasma and 24-hour urine sample were assayed using an atomic absorption spectrophotometer. The anthropometric measurements and 3-day food record were also evaluated. A linear mixed model was used to compare the plasma concentration versus interval after the oral dose, before and after surgery. RESULTS The pre- and postoperative test results revealed a significantly lower plasma zinc response (P <.01) and a delayed response to iron intake after surgery. The total plasma iron concentration area, during the 4 hours, was not different after surgery (P >.05). The 24-hour urinary iron and zinc excretion did not differ between the pre- and postoperative phases. CONCLUSION The present data showed a compromised response to the zinc tolerance test after gastric bypass surgery, suggesting an impaired absorption of zinc. More attention must be devoted to zinc nutritional status after surgery.

Total Nitrogen and Free Amino Acid Losses and Protein Calorie Malnutrition of Hemodialysis Patients: Do They Really Matter?’

Background/Aims: Protein calorie malnutrition (PCM) in patients on hemodialysis (HD) is multifactorial; however, HD per se induces nutrient losses. The aim of the present study was to characterize the losses of total nitrogen (TN) and free amino acids (FAs) through the dialysate and to determine the relationship between this loss and PCM, food ingestion, and the characteristics of the hemodialyzer in patients on HD. Methods: In a prospective study, 21 patients submitted to low-flux HD 3 times a week were evaluated within a period of 6 months regarding nutritional status, dietary calorie and protein intake, and losses through the dialysate of TN, FA, and urea nitrogen (UN). The type, surface area and reuses (up to 12) of the dialysis membrane were determined on each occasion, and the adequacy of dialysis was estimated by Kt/V. Results: 50% of the patients were considered malnourished, although the mean protein and energy intakes were similar for the malnourished and nourished patients. Mean TN losses through the dialysate were 16 g/session (60% UN). FA losses varied from 3.8 to 4.2 g/total volume. TN and FA in the dialysate did not differ significantly between malnourished and nourished patients. There was a positive correlation between membrane (polysulfone) area and TN (p <0.05) and ultrafiltrate volume and TN (p < 0.05), and a nonsignificant correlation between reuse of the dialysis membrane and TN. Conclusions: TN and FA losses through the dialysate were similar for malnourished and non-malnourished patients on chronic HD, thus they do not act as indicators of nutritional status impairment.

Enzymatic inactivation of bradykinin by rat brain neuronal perikarya

Summary1.Bradykinin (Bk; Arg1-Pro2-Pro3-Gly4-Phe5-Ser6-Pro7-Phe8-Arg8) inactivation by bulk isolated neurons from rat brain is described.2.Bk is rapidly inactivated by neuronal perikarya (4.2 ± 0.6 fmol/min/cell body).3.Sites of inactivating cleavages, determined by a kininase bioassay combined with a time-course Bk-product analysis, were the Phe5-Ser6, Pro7-Phe8, Gly4-Phe5, and Pro3-Gly4 peptide bonds. The cleavage of the Phe5-Ser6 bond inactivated Bk at least five fold faster than the other observed cleavages.4.Inactivating peptidases were identified by the effect of inhibitors on Bk-product formation. The Phe5-Ser6 bond cleavage is attributed mainly to a calcium-activated thiol-endopeptidase, a predominantly soluble enzyme which did not behave as a metalloenzyme upon dialysis and was strongly inhibited byN-[1(R,S)-carboyx-2-phenylethyl]-Ala-Ala-Phe-p-aminobenzoate and endo-oligopeptidase A antiserum. Thus, neuronal perikarya thiol-endopeptidase seems to differ from endo-oligopeptidase A and endopeptidase 24.15.5.Endopeptidase 24.11 cleaves Bk at the Gly4-Phe5 and, to a larger extent, at the Pro7-Phe8 bond. The latter bond is also cleaved by angiotensin-converting enzyme (ACE) and prolyl endopeptidase (PE). PE also hydrolyzes Bk at the Pro3-Gly4 bond.6.Secondary processing of Bk inactivation products occurs by (1) a rapid cleavage of Ser6-Pro7-Phe8-Arg8 at the Pro7-Phe8 bond by endopeptidase 24.11, 3820ACE, and PE; (2) a bestatin-sensitive breakdown of Phe8-Arg9; and (3) conversion of Arg1-Pro7 to Arg1-Phe5, of Gly4-Arg9 to both Gly4-Pro7 and Ser6-Arg9, and of Phe5-Arg9 to Ser6-Arg9, Phe8-Arg9, and Ser6-Pro7, by unidentified peptidases.7.A model for the enzymatic inactivation of bradykinin by rat brain neuronal perikarya is proposed.

Impact of Aging on Urinary Excretion of Iron and Zinc

Project Data about the influence of aging on urinary excretion of iron and zinc are scarce. The objective of the present study was to compare the concentration of zinc and iron in the urine of healthy elderly subjects and younger adults. Procedure Seven healthy elderly subjects and seven younger adults were selected and submitted to biochemical, clinical, and nutritional tests. After a fasting period, 12-hour urine was collected for the determination of iron and zinc concentrations by graphite furnace atomic absorption spectrophotometry. Results Urinary zinc and iron concentrations of the elderly subjects were not significantly different from that of younger adults. However, the total zinc and iron urinary clearance in 24 hours for the elderly was significantly higher compared with that of younger adults. Conclusion There is an increase in urinary iron and zinc clearance with aging. The values reported in this manuscript may be used as references in future studies.

Mudanças no estilo de vida e fatores de risco para doenças crônicas não transmissíveis e sistema imune de mulheres sedentárias

OBJECTIVE: The objective of this study was to observe the effects of two months of a lifestyle-changing program on the immune system and risk of non-communicable chronic diseases and how they associate with each other and with body composition. METHODS: Fifty women aged 36 years (SD=10) with a mean body mass index of 31kg/m2 (SD=12) participated in this study. The following data were investigated: body composition (by anthropometry and bioimpedance), complete blood count, lipid profile, plasma concentrations of vitamins A and C, beta-carotene, zinc, uric acid and glucose. The program consisted of circuit weight training or walking for 1 hour, three times per week during the first month and for 1 hour, four times per week during the second month and changes to their eating habits. RESULTS: There was a significant reduction in body fat and plasma concentrations of uric acid, total cholesterol and high-density lipoprotein. Triglycerides, low density lipoprotein and immune system variables remained unchanged. Zinc was not associated with any variable. The leukocytes, lymphocytes, platelets and vitamin C were positively associated with body fat and negatively associated when divided by body mass (kg). Total cholesterol and low-density lipoprotein divided by vitamin A and beta-carotene concentrations had a negative correlation with body fat. Vitamin C correlated the most with other biochemical risk factors. CONCLUSION: The risk factors for non-communicable chronic diseases reduced, but immune system markers remained unchanged. Increased body fat was negatively associated with immune system markers and vitamins.

Experimental induction of steatosis in different tissues after the ingestion of a carbohydrate-rich diet: effect on the liver, on the heart and on indicators of oxidation

CONTEXT The western dietary pattern is characterized by a high calorie intake with a high proportion of simple sugars. This diet is associated with comorbidities such as hepatic fat deposition and is possibly related to non-alcoholic fatty liver disease. OBJECTIVE To evaluate the capacity of a hyperglucidic diet to induce steatosis in adult male Wistar rats. After the administration of a carbohydrate-rich diet, we also evaluated the presence of hepatic and cardiac steatosis and the levels of intrinsic antioxidants in the liver. METHODS Forty-six eutrophic adult male Wistar rats were used and 10 of them were chosen, at random, to serve as controls, while the remaining ones formed the experimental group. Control animals received the standard ration offered by the animal house and the experimental group received the hyperglucidic diet. The diets were offered for 21 days and, at the end of this period, tissue samples were collected for analysis of indicators of oxidative stress (malondialdehyde, and reduced glutathione) and of vitamin E. The animals were then sacrificed by decapitation and their viscera were removed for analysis of liver and heart fat. RESULTS The hyperglucidic diet used induced hepatic fat deposition, with lipid vacuoles being detected in 83% of the livers analyzed by histology. No lipid vacuoles were observed in the heart. Malondialdehyde and reduced glutathione levels remained unchanged when the animals were submitted to the hyperglucidic diet, probably because there was no liver development of fibrosis or inflammation. In contrast, the levels of vitamin E (antioxidant) were reduced, as confirmed in the literature for steatotic animals. CONCLUSION The hyperglucidic diet induced hepatic steatosis. In the heart there was an increase in fat content, although no histological changes were observed. These alterations cannot be explained by the presence of malondialdehyde or reduced glutathione (indicators of oxidation), since the values were similar in the groups studied. However, a significant reduction of vitamin E was observed in the experimental group.

Brazilian honey samples evaluated by physical-chemical and carbon isotope ratio analysis

1 Laboratório de Espectrometria de Massa da Divisão de Nutrição do Departamento de Clínica Médica da Faculdade de Medicina de Ribeirão Preto Universitário São Paulo, Anexo A 1o Andar Avenida Bandeirantes 3900 Campus Universitário, Ribeirão Preto, SP 14049-900, Brazil. 2 Departamento de Genética da Faculdade de Medicina de Ribeirão Preto – Universitário São Paulo, Brazil. 3 Instituto Adolfo Lutz, Laboratório de Ribeirão Preto, São Paulo, Brazil.

Caloric value in foods consumed by children and adolescents determined through direct calorimetry

Obesidade, diabetes mellitus, insuficiência renal e dislipidemias entre inúmeras outras são condições mórbidas nas quais a modificação dietética é parte essencial do tratamento (Allison et al., 1993). Diante disso, a determinação e quantificação dos nutrientes de alimentos tornase fundamental para a real ização de um planejamento alimentar adequado. O planejamento dietético geralmente é realizado com informações contidas nas tabelas de composição de alimentos, como a do Instituto Brasileiro... (1977), a de Franco (1992) e a Tabela Brasileira de Composição de Alimentos (Lajolo et al., 2000), ou nos rótulos de produtos industrializados. As informações nutricionais, entretanto, não devem ser consideradas absolutas, pois os valores energéticos e nutricionais de um mesmo alimento variam consideravelmente entre as citadas fontes de informação. Além disso, diversos produtos freqüentemente consumidos por crianças e adolescentes como balas, doces, biscoitos e bolachas (Sawaya et al., 1995), raramente são encontrados nestas tabelas.