Influence of protein malnutrition on cutaneous wound healing in rats / Impacto da desnutrição proteica na cicatrização de feridas cutâneas em ratos

ABSTRACT Objective Investigate histological changes related to inflammatory response and collagen expression during wound healing in rats with protein malnutrition. Methods Twenty male Wistar rats underwent cutaneous surgery and were divided into two experimental groups: Malnourished (8% casein diet); Nourished (17% casein diet). Animals were euthanized after 5th and 10th days, descriptive and quantitative analyses were performed on sections stained with hematoxylin-eosin and sirius red, respectively. Statistical analysis of data using nonparametric Fisher's exact test with p<0.05 was carried out. Results At five days, increased fibroblast proliferation (p<0.01) and collagen expression (p<0.05) was observed in N5 group. After ten days, N10 and MN10 animals showed higher amount of granulation tissue and edema/inflammatory infiltrate independent of nutritional status (p>0.05), only N10 group showed fibroblast proliferation (p<0.01) and increased collagen expression (p<0.01). Conclusion Protein malnutrition seems not to influence inflammatory phase of healing, whereas it negatively effects fibroblast proliferation and collagen synthesis.

RESUMO Objetivo Investigar as alterações histológicas relacionadas à resposta inflamatória e à expressão de colágeno durante a cicatrização em ratos com desnutrição protéica. Métodos Vinte ratos Wistar machos foram submetidos à cirurgia cutânea e divididos em dois grupos experimentais: Desnutridos (dieta com caseína a 8%); Nutridos (17% de dieta com caseína). Animais foram eutanasiados após 5 e 10 dias, análises descritivas e quantitativas foram realizadas em cortes corados com hematoxilina-eosina e sirius vermelho, respectivamente. Análise estatística dos dados utilizando teste exato não paramétrico de Fisher com p<0,05 foi realizada. Resultados Aos cinco dias, observou-se aumento da proliferação fibroblástica (p<0,01) e expressão de colágeno (p<0,05) no grupo N5. Após 10 dias, animais N10 e MN10 apresentaram maior quantidade de tecido de granulação e edema/infiltrado inflamatório independente do estado nutricional (p>0,05), apenas grupo N10 apresentou proliferação fibroblástica (p<0,01) e aumento da expressão de colágeno (p<0,01). Conclusão A desnutrição protéica parece não influenciar na fase inflamatória da cicatrização, porém afeta negativamente a proliferação de fibroblastos e a síntese de colágeno.

Preoperative nutritional status and clinical complications in the postoperative period of cardiac surgeries

Abstract Objective: This study aims to assess the preoperative nutritional status of patients and the role it plays in the occurrence of clinical complications in the postoperative period of major elective cardiac surgeries. Methods: Cross-sectional study comprising 72 patients aged 20 years or older, who underwent elective cardiac surgery. The preoperative nutritional assessment consisted of nutritional screening, anthropometry (including the measurement of the adductor pollicis muscle thickness) and biochemical tests. The patients were monitored for up to 10 days after the surgery in order to control the occurrence of postoperative complications. The R software, version 3.0.2, was used to statistically analyze the data. Results: Clinical complications were found in 62.5% (n=42) of the studied samples and complications of non-infectious nature were most often found. Serum albumin appeared to be associated with renal complications (P=0.026) in the nutritional status indicators analyzed herein. The adductor pollicis muscle thickness was associated with infectious complications and presented mean of 9.39±2.32 mm in the non-dominant hand (P=0.030). No significant correlation was found between the other indicators and the clinical complications. Conclusion: The adductor pollicis muscle thickness and the serum albumin seemed be associated with clinical complications in the postoperative period of cardiac surgeries.

Efeito do tratamento com triptofano sobre parâmetros do comportamento alimentar em ratos adultos submetidos à desnutrição neonatal / Effects of tryptophan on the eating behavior of adult rats with neonatal malnutrition

OBJETIVO: Investigou-se os efeitos do tratamento com triptofano sobre o consumo alimentar em ratos adultos, submetidos ou não a desnutrição precoce. MÉTODOS: Sessenta e quatro ratos Wistar machos foram divididos em nutridos (n=32, caseína=17 por cento) e desnutridos (n=32, caseína=8 por cento), de acordo com a dieta materna empregada no período de lactação. Após o desmame, todos os ratos receberam dieta com 23 por cento de proteína. Pesos corporais foram avaliados no sétimo, vigésimo primeiro e septuagésimo dias de vida. Aos setenta dias de idade, cada grupo nutricional foi dividido em subgrupos: Nutrido-Salina (n=16) e Nutrido-Triptofano (n=16), Desnutrido-Salina (n=16) e Desnutrido-Triptofano (n=16). Os grupos receberam diariamente 1,0mL/100g de triptofano, na dose de 50mg/kgP ou salina (0,9 por centoNaCl), durante 14 dias. Neste período foram realizados os estudos dos parâmetros do comportamento alimentar. Posteriormente obteve-se a média do consumo alimentar relativo e a média do ganho de peso relativo. As análises estatísticas foram feitas utilizando os testes t Student e ANOVA seguido de Tukey, com p<0,05. RESULTADOS: As ninhadas de mães alimentadas com dieta hipoproteica mantiveram pesos inferiores comparados com as ninhadas nutridas (p<0,01) até os setenta dias de vida. Os ratos nutridos tratados com triptofano (M=6,88, DP=0,05) reduziram a ingestão alimentar comparados aos nutridos salina (M=7,27, DP=0,08) (p<0,01). Contudo, não houve efeito sobre o ganho de peso. Entre os desnutridos nenhuma diferença foi encontrada. CONCLUSÃO: Nesse estudo, a restrição proteica neonatal alterou a evolução ponderal em ratos. Além disso, a desnutrição precoce tornou os ratos adultos resistentes aos efeitos inibitórios do triptofano sobre a ingestão alimentar.

OBJECTIVE: This study investigated the effects of tryptophan on the eating behavior of adult rats submitted or not to early malnutrition. METHODS: Sixty-four male Wistar rats were divided into nourished (n=32, casein=17 percent) and malnourished (n=32, casein=8 percent) according to the diet given to the dam during lactation. After weaning, all rats were fed a diet with a protein content of 23 percent. The rats were weighed on day 7, day 21 and day 70 after birth. On day 70 after birth, each nutritional group was divided into 4 subgroups: nourished-saline (n=16), nourished-tryptophan (n=16), malnourished-saline (n=16) and malnourished-tryptophan (n=16). The tryptophan groups were given 1.0mL/100g of tryptophan for 14 days, at a dosage of 50mg/kgw of body weight and the saline groups were given 1.0mL/100g of 0.9 percent NaCl, also for 14 days. The eating behavior parameters were assessed during this period. The mean relative food intake and mean relative weight gain were then determined. The statistical analyses were done by the Student's t-test and ANOVA, followed by the Tukey test, with p<0.05. RESULTS: During the first 70 days of life, pups from protein-malnourished damns remained lighter than pups from well-nourished damns (p<0.01). Well-nourished rats treated with tryptophan (M=6.88, SD=0.05) ate less than those given saline (M=7.27, SD=0.08) (p<0.01) but weight was unaffected. No difference was found for the malnourished rats. CONCLUSION: In this study, neonatal protein restriction affected weight gain in rats. Furthermore, early malnutrition made adult rats resistant to the inhibitory effects of tryptophan on food intake.