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1.
World Dev ; 135: 105064, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32834377

RESUMEN

Emerging evidence supports the intuitive link between chronic health conditions associated with air pollution and the vulnerability of individuals and communities to COVID-19. Poor air quality already imposes a highly significant public health burden in Northwest India, with pollution levels spiking to hazardous levels in November and early December when rice crop residues are burned. The urgency of curtailing the COVID-19 pandemic and mitigating a potential resurgence later in the year provides even more justification for accelerating efforts to dramatically reduce open agricultural burning in India.

2.
Am J Transplant ; 13(2): 493-500, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23205849

RESUMEN

Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) following kidney transplantation occurs in a large percentage of patients. Accurate prediction of recurrence and elucidation of its pathogenesis are major therapeutic goals. To detect differential proteins related to FSGS recurrence, proteomic analysis was performed on plasma and urine samples from 35 transplanted idiopathic FSGS patients, divided into relapsing and nonrelapsing. Several proteins were detected increased in urine of relapsing FSGS patients, including a high molecular weight form of apolipoprotein A-I, named ApoA-Ib, found exclusively in relapsing patients. This finding was verified by Western blot individually in the 35 patients and validated in an independent group of 40 patients with relapsing or nonrelapsing FSGS, plus two additional groups: FSGS-unrelated patients showing different proteinuria levels (n = 30), and familial FSGS transplanted patients (n = 14). In the total of 119 patients studied, the ApoA-Ib form was detected in 13 of the 14 relapsing FSGS patients, and in one of the 61 nonrelapsing patients. Only one of the 30 patients with FSGS-unrelated proteinuria tested positive for ApoA-Ib, and was not detected in familial patients. Urinary ApoA-Ib is associated with relapses in idiopathic FSGS and warrants additional investigation to determine its usefulness as biomarker of relapse following transplantation.


Asunto(s)
Apolipoproteína A-I/sangre , Apolipoproteína A-I/orina , Glomeruloesclerosis Focal y Segmentaria/terapia , Trasplante de Riñón/métodos , Biomarcadores/sangre , Biomarcadores/orina , Cromatografía Liquida , Electroforesis en Gel Bidimensional , Glomeruloesclerosis Focal y Segmentaria/sangre , Glomeruloesclerosis Focal y Segmentaria/orina , Humanos , Proteómica , Recurrencia , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
3.
Theor Appl Genet ; 119(5): 875-88, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19578830

RESUMEN

Replacement of crop landraces by modern varieties is thought to cause diversity loss. We studied genetic erosion in maize within a model system; modernized smallholder agriculture in southern Mexico. The local seed supply was described through interviews and in situ seed collection. In spite of the dominance of commercial seed, the informal seed system was found to persist. True landraces were rare and most informal seed was derived from modern varieties (creolized). Seed lots were characterized for agronomical traits and molecular markers. We avoided the problem of non-consistent nomenclature by taking individual seed lots as the basis for diversity inference. We defined diversity as the weighted average distance between seed lots. Diversity was calculated for subsets of the seed supply to assess the impact of replacing traditional landraces with any of these subsets. Results were different for molecular markers, ear- and vegetative/flowering traits. Nonetheless, creolized varieties showed low diversity for all traits. These varieties were distinct from traditional landraces and little differentiated from their ancestral stocks. Although adoption of creolized maize into the informal seed system has lowered diversity as compared to traditional landraces, genetic erosion was moderated by the distinct features offered by modern varieties.


Asunto(s)
Agricultura , Zea mays/genética , Biomasa , Análisis por Conglomerados , Variación Genética , Geografía , México , Fenotipo , Filogenia , Carácter Cuantitativo Heredable , Semillas/genética , Semillas/crecimiento & desarrollo
4.
Eur J Clin Nutr ; 62(2): 254-62, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17375114

RESUMEN

BACKGROUND: The metabolic response to surgery includes alterations in protein metabolism, resulting in a net loss of proteins. Protein hypercatabolism is considered an unavoidable consequence of injury, and an important source of morbidity and mortality. Our purpose was to determine the effect of nutrition on protein metabolism following gastrointestinal surgery, and to elucidate whether postoperative protein loss can be prevented with adequate nutritional support. METHODS: Patients who had undergone gastrointestinal surgery were given four different parenteral nutritions with increasing glucose, lipid and amino acid content during the 7 days following surgery. Nitrogen balance, protein synthesis and protein breakdown were determined using in vivo stable isotope labelling. Other metabolites (3-methylhistidine, creatinine, urea, cortisol, glucose, insulin, amino acids and C-reactive protein) were measured. RESULTS: A nutrition-dependent alteration of protein metabolism was found in response to surgical injury. Nutrition modified nitrogen balance, whole-body protein breakdown and, to a lesser extent, whole-body protein synthesis and muscle protein breakdown. The low-energy parenteral nutrition without amino acids produced a negative nitrogen balance (postoperative day 7=-0.381 g protein kg(-1)day(-1)) and important alterations in postoperative protein metabolism that did not normalize during the study period (day 7 protein synthesis=239% and protein breakdown 217% vs preoperative). Patients receiving the two low energy parenteral nutritions containing amino acids had a less negative nitrogen balance (day 7=-0.011 and -0.133 g protein kg(-1)day(-1)) and a transient increase in protein metabolism. The complete parenteral nutrition maintained, during all studied days, protein metabolism parameters within the preoperative reference range (synthesis day 2=92%, day 4=110% day 7=79%; breakdown day 2=85%, day 4=80%, day 7=76% vs preoperative) and a positive nitrogen balance (day 2=+0.0387, day 4=+0.578 and day 7=+0.227 g protein kg(-1)day(-1)). CONCLUSION: Complete nutritional support can prevent protein loss after gastrointestinal surgery and maintain protein metabolism without alterations.


Asunto(s)
Abdomen/cirugía , Alimentos Formulados , Proteínas Musculares/metabolismo , Necesidades Nutricionales , Nutrición Parenteral/métodos , Proteínas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Aminoácidos/análisis , Aminoácidos/uso terapéutico , Carbohidratos/análisis , Procedimientos Quirúrgicos del Sistema Digestivo , Grasas/análisis , Femenino , Alimentos Formulados/análisis , Humanos , Masculino , Persona de Mediana Edad , Nitrógeno/metabolismo , Cuidados Posoperatorios , Periodo Posoperatorio
5.
Clin Nutr ; 21(2): 119-25, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12056783

RESUMEN

BACKGROUND AND AIMS: Biochemical indicators are used to assess the adequacy of nutritional support given to postoperative patients. However, the metabolic alterations present in these patients diminish the efficiency of these indicators. The objective of this work is to determine the usefulness of short-lived proteins as indicators to assess the nutritional support administered to patients during the metabolic stress phase produced by surgery. METHODS: The nitrogen balance and plasma concentrations of transthyretin, retinol binding protein, and insulin-like growth factor-1 were determined in 24 patients who received 4 different nutritional regimens during 7 days after surgery. RESULTS: Transthyretin and retinol binding protein, although sensitive to nutritional intake (P<0.0005 and P<0.04 respectively), were strongly affected by the stress response (P<0.008 and P<0.0003 respectively), thus limiting their usefulness for nutrition assessment. Insulin-like growth factor-1 was not influenced by the stress response and was sensitive to the nutritional supply (P<0.0001). Insulin-like growth factor-1 was the only component that showed similar efficiency than nitrogen balance as nutritional indicator. CONCLUSIONS: Transthyretin and retinol binding protein are not adequate to assess the nutritional supply during the stress phase after surgery, while insulin-like growth factor-1 is a suitable indicator of the adequacy of recent intake in this situation, similar in performance to nitrogen balance.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina/análisis , Evaluación Nutricional , Prealbúmina/análisis , Proteínas de Unión al Retinol/análisis , Estrés Fisiológico/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/análisis , Proteínas Sanguíneas/análisis , Femenino , Humanos , Indicadores y Reactivos , Masculino , Persona de Mediana Edad , Nitrógeno/metabolismo , Estado Nutricional , Apoyo Nutricional/normas , Cuidados Posoperatorios/normas , Periodo Posoperatorio , Proteínas Plasmáticas de Unión al Retinol , Sensibilidad y Especificidad
6.
Clin Nutr ; 16(2): 67-73, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16844572

RESUMEN

This work attempts to determine if there are differences in protein metabolism in post-surgical patients who receive parenteral nutrition with amino acids plus glucose (G+AA) or conventional gluco-salinal solution (GS). Eighteen patients submitted to gastrointestinal surgery were randomized and double-blindly administered either G+AA (1 g AA/kg x d and 28 kJ/kg x d), or GS (28 kJ/kg x d). Protein metabolism was determined 12 h after surgery (day 0) and after 5 days of nutritional support. On day 0, protein breakdown was similarly elevated, with respect to reference values, in both groups (GS: 4.62 +/- 0.25; G+AA: 5.25 +/- 0.50 g prot/kg x d) as a result of surgical stress. These values increased significantly at day 5 (P < 0.03) with the administration of GS to 6.93 +/- 1.00 g prot/kg x d, while they decreased (P < 0.002, 3.30 +/- 0.42 g prot/kg x d) with G+AA. Protein synthesis was increased (5.69 +/- 0.86 g prot/kg x d) with GS (P < 0.02), and was decreased (2.79 +/- 0.44 g prot/kg x d) with G+AA (P < 0.0002). Both synthesis and breakdown were inside normal reference values after 5 days for group G+AA. In both groups, nitrogen balance did not change significantly at day 5 compared to day 0. G+AA is effective in curbing the hypermetabolism produced by postoperative stress, achieving normal protein metabolism in 5 days, while GS increases the protein breakdown and synthesis. Nitrogen balance does not detect these modifications of the protein metabolism. Undernutrition on prognosis is not yet fully recognized.

7.
Life Sci ; 63(1): 13-21, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9667760

RESUMEN

Cumulative damage in cells from aged people could lead to a greater fragility against acute oxidative stress. The effects of acute oxidative stress on cell viability, cAMP and cGMP concentrations, and protein synthesis rates were studied in lymphocytes from 25 young and 26 elderly subjects. Lymphocytes were exposed to stress by hydrogen peroxide 25 micromol/l and incubated for 18 hours. Cell viability after stress was lower (p<0.0001, Student's t test) in cells from the elderly (63.4%) than in cells from the young donors (73.2%). The protein synthesis rate was also lower after stress (p<0.04, Mann-Whitney U test) in cells from the elderly (47.3% vs. non-stressed cells), than in cells from the young (82.19% vs. non-stressed cells). After oxidative stress, cAMP and cGMP concentrations showed no significant changes in cells from young subjects; there were, however, significant decreases in these cyclic nucleotides in cells from the elderly (p<0.008 for both nucleotides, paired Student's t test). There were no differences in basal cAMP or cGMP levels between the two groups. These results show that mortality and metabolic changes due to oxidative stress are greater in lymphocytes proceeding from elderly subjects than in those from young subjects.


Asunto(s)
Linfocitos/metabolismo , Estrés Oxidativo , Proteínas/metabolismo , Sistemas de Mensajero Secundario , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Supervivencia Celular/efectos de los fármacos , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Humanos , Peróxido de Hidrógeno/farmacología , Linfocitos/efectos de los fármacos , Oxidantes/farmacología
8.
J Psychosom Res ; 39(5): 633-40, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7490698

RESUMEN

Degree of premorbid 'action-proneness' was measured, using a self-administered questionnaire, in 35 patients suffering from chronic fatigue syndrome (CFS), all the members of 'ME'-self help groups and all those meeting CDC-criteria of CFS. The results were compared with those of 30 chronic idiopathic musculoskeletal pain patients, 34 patients with a chronic organic condition, and 34 neurotic patients without primary somatic complaints. Statistical analysis showed that CFS patients described themselves as significantly more 'action-prone' than the last two groups, and to a degree which was comparable with the chronic pain group. The results could not be explained by concomitant depression and are in accordance with anecdotal reports of premorbid hyperactive lifestyle in CFS patients. Further investigations seem worthwhile to test the hypothesis that hyperactivity might be a predisposing factor for chronic illness behaviour in CFS patients.


Asunto(s)
Nivel de Alerta , Síndrome de Fatiga Crónica/psicología , Inventario de Personalidad/estadística & datos numéricos , Solución de Problemas , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psicometría , Factores de Riesgo , Grupos de Autoayuda
9.
J Biochem Biophys Methods ; 27(1): 57-63, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8409211

RESUMEN

Protein synthesis rate determinations in vivo using L-[1-14C]-leucine may be underestimated because of contamination by radioactive ketoisocaproate (KIC) resulting from leucine metabolism. The aim of this work was to set up a reliable method to determine the KIC/leucine radioactivity ratio in protein-free homogenates, and to apply it to study the extent of the protein synthesis ratio error due to KIC contamination. Cation-exchange chromatography using Dowex AG 50W-X8 resin was used to separate KIC from leucine, eluting KIC with water and leucine with 4 M ammonia. The errors found in the protein synthesis ratio were 6.20% in liver and 2.34% in jejunum.


Asunto(s)
Contaminación de Medicamentos , Mucosa Intestinal/metabolismo , Cetoácidos , Leucina/metabolismo , Hígado/metabolismo , Biosíntesis de Proteínas , Animales , Radioisótopos de Carbono , Cromatografía por Intercambio Iónico , Yeyuno , Cetoácidos/aislamiento & purificación , Cetoácidos/metabolismo , Leucina/aislamiento & purificación , Masculino , Técnica de Dilución de Radioisótopos , Ratas , Ratas Sprague-Dawley
10.
Physiol Res ; 44(4): 233-9, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8789642

RESUMEN

To investigate the effect of glutamine-enriched total parenteral nutrition (TPN) on the protein synthesis and morphology of jejunal mucosa in non-hypercatabolic stress, sixty-two male Sprague-Dawley rats were subjected to surgical stress by femoral fracture. The rats were divided into 3 groups and received TPN for 8 days. One group received a standard amino acid solution without glutamine, the second group a standard solution enriched with glycine and glutamic acid, and the third group a standard solution enriched with glycyl-glutamine. All regimens were isocaloric and isonitrogenous-nitrogen (2.2 g/kg.day), glucose (150 Kcal/kg.day), and lipids (150 Kcal/kg.day). There were no statistically significant differences in jejunal mucosal thickness, DNA content, protein content, fractional synthesis rate or absolute protein synthesis among the groups after eight days of parenteral nutrition. In conclusion, the addition of glutamine to TPN did not influence either protein metabolism or morphology of the jejunal mucosa in non-hypercatabolic surgical stress.


Asunto(s)
Glutamina/farmacología , Mucosa Intestinal/metabolismo , Yeyuno/metabolismo , Biosíntesis de Proteínas , Estrés Fisiológico/metabolismo , Animales , ADN/análisis , Fracturas del Fémur , Mucosa Intestinal/patología , Yeyuno/efectos de los fármacos , Yeyuno/patología , Masculino , Tamaño de los Órganos , Nutrición Parenteral Total , Ratas , Ratas Sprague-Dawley
11.
Physiol Res ; 46(3): 181-6, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9728504

RESUMEN

We have studied the effects of hypocaloric diets with different supplements on liver and jejunal mucosa protein synthesis. The supplements assayed were medium chain triglycerides (diet MCT, with 50% carbohydrates: 25% long chain triglycerides (LCT): 25% medium chain triglycerides (MCT), standard amino acids), branched-chain amino acids (diet BCA, identical to control diet L50, with 15.3% of nitrogen replaced by branched-chain amino acids) and glutamine (diet GLN, identical to diet L50, with 15.3% of nitrogen replaced by glutamine). The control diet (L50) had 50% carbohydrates: 50% LCT and standard amino acids. The diets were assayed on 86 rats with femoral fracture immobilized by Kirschner pin insertion. Nutrition was administered for 4 days. On the fifth day, liver and jejunal mucosa protein synthesis was determined. A branched-chain amino acid supply in a proportion higher than 21.2% of amino acid nitrogen significantly decreased liver and jejunal mucosa protein synthesis, while the same amount of glutamine did not modify it. MCT had no effect on jejunal mucosa protein synthesis, while it was decreased significantly in the liver.


Asunto(s)
Ingestión de Energía , Nutrición Parenteral , Cuidados Posoperatorios , Biosíntesis de Proteínas , Estrés Fisiológico , Aminoácidos de Cadena Ramificada/administración & dosificación , Animales , Atrofia , Carbohidratos/administración & dosificación , Fracturas del Fémur/cirugía , Glutamina/administración & dosificación , Mucosa Intestinal/metabolismo , Intestinos/patología , Yeyuno/metabolismo , Hígado/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Triglicéridos/administración & dosificación
12.
Physiol Res ; 46(3): 187-91, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9728505

RESUMEN

The aim of this work was to study the effects of low energy parenteral diets with different lipid/glucose ratios on rat liver and jejunal mucosa protein synthesis. The studied diets were: L0 (100% glucose, control diet), L25 (25% lipids: 75% glucose), L50 (50% lipids: 50% glucose) and L75 (75% lipids: 25 % glucose). All diets were isoenergetic and isonitrogenated, with a standard amino acid content. The diets were assayed in 93 rats with open femoral fracture immobilized by Kirschner pin insertion. The diets were administered for 4 days. On the fifth day, liver and jejunal mucosa protein synthesis were determined. Highest liver protein synthesis rates were obtained with the diet compositions: lipid/carbohydrate ratio: 25% lipids and 75% carbohydrates (expressed as energy ratio). A higher proportion of lipids significantly decreases liver protein synthesis (p <0.05). Jejunal mucosa protein synthesis followed the same pattern, with the same statistical differences.


Asunto(s)
Ingestión de Energía , Glucosa/administración & dosificación , Lípidos/administración & dosificación , Nutrición Parenteral , Cuidados Posoperatorios , Biosíntesis de Proteínas , Estrés Fisiológico , Animales , Fracturas del Fémur/cirugía , Mucosa Intestinal/metabolismo , Yeyuno/metabolismo , Cetoácidos/análisis , Hígado/metabolismo , Masculino , Nitrógeno/administración & dosificación , Control de Calidad , Ratas , Ratas Sprague-Dawley
13.
Arch Physiol Biochem ; 105(4): 337-41, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9711353

RESUMEN

To investigate the amino acid requirements of the senescent rat, as part of a study directed toward nutritional support in the aged, it was necessary to determine amino acid levels in plasma and tissue, but also regional blood flow of the animals subjected to fast. Only this latter allows the determination of the amounts of each amino acid present in the tissue before starvation by extrapolation of values measured during starvation. As plasma and tissue amino acid had been previously determined, the aim of this study had been to measure regional blood flow in the liver, kidney, testis, spleen, stomach, small intestine and large intestine in senescent rats submitted to 1, 5, 9 and 15 days of starvation. Twenty-four-month-old male Wistar rats (n = 16) were divided into four groups (n = 4), and submitted to starvation for 1, 5, 9 and 15 days. Blood flow in the liver, kidney, testis, spleen, stomach, and small and large intestine was measured by injecting 0.5 ml of a microsphere solution (15 microns diameter) labelled with 57Co, 0.25 microCi/ml. Over the 15-day period studied, the response to starvation showed two distinct phases: an early effect (from day 1 to day 9) in which there were decreases in the weight of the organs and in organ blood flow, and a second phase (from day 9 to day 15) in which blood flow and organ weight were maintained. However, organ blood flow related to mass was not substantially affected by starvation. This implies that measurement of substrate plasma concentration alone can reliably reflect organ substrate flow.


Asunto(s)
Envejecimiento/fisiología , Inanición , Animales , Intestinos/irrigación sanguínea , Riñón/irrigación sanguínea , Hígado/irrigación sanguínea , Masculino , Tamaño de los Órganos/fisiología , Ratas , Ratas Wistar , Flujo Sanguíneo Regional , Bazo/irrigación sanguínea , Estómago/irrigación sanguínea , Testículo/irrigación sanguínea
14.
Med Clin (Barc) ; 100(18): 692-8, 1993 May 08.
Artículo en Español | MEDLINE | ID: mdl-8492597

RESUMEN

BACKGROUND: Anthropometry is an effective method used in the evaluation of the state of nutrition. Anthropometric reference values obtained from the general population have frequently been used. The aim of this study was to determine the anthropometric parameters of the elderly in Manresa and demonstrate the different evolution of these values in both sexes between the ages of 65 and 85 or more. METHODS: Following randomization a representative sample of 1,034 healthy elderly subjects living in Manresa was obtained with the following being determined: weight, height, tricipital, subscapular and abdominal fat folds, arm circumference, arm muscle perimeter, weight/height indexes, muscle and fat areas of the arm and percentage of fat. All the measurements were obtained by the same person with the use of a tallimeter scale with a flexible metric tape and a Holtain lipocalibrater. RESULTS: The values are presented in percentiles by subgroups of age and sex. The weight, height and indexes of lean mass were greater in males while those determining fatty mass were greater in females. In females all the values decreased between 65 and 85 or more years of age (p < 0.001), while in males all decreased (p < 0.001) except; tricipital and abdominal skin folds. Upon comparison of these parameters with those obtained in other geographic areas, differences were observed between both. CONCLUSIONS: By the characteristics of the population studied it was considered that the anthropometric parameters obtained are extensible to all the elderly population of Catalonia and may be used as reference values of the same.


Asunto(s)
Anciano , Antropometría , Anciano de 80 o más Años , Composición Corporal , Estatura , Peso Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estado Nutricional , Valores de Referencia , Factores Sexuales , Grosor de los Pliegues Cutáneos , España
15.
Nutr Hosp ; 8(9): 567-73, 1993 Dec.
Artículo en Español | MEDLINE | ID: mdl-8110871

RESUMEN

A study was made of the possible influence of sepsis on liver protein synthesis in septic and control rats, fed either parenterally (TPN) or with water and feed available "ad libitum". Liver protein synthesis was determined using the single massive dose method. In experiment I, the septic and control animals received TPN for twenty-four hours: in experiment II water and food was available to them "ad libitum". Twenty-four hours after the sepsis occurred, the animals were injected with a massive dose of 14C-labelled leucine, and slaughtered by decapitation. The septic animals with water and feed available "ad libitum" were fasted voluntarily without any intake. This group of fasted septic animals was the only one which lost weight. Liver protein synthesis increased in septic animals in comparison with the control animals, whether receiving TPN (112.2 +/- 8/78.5 +/- 13) or with "ad libitum" nutrition (97.2 +/- 15/60.8 +/- 8). The increased liver protein synthesis in the septic animals was modified (although with reduced significance) by parenteral nutrition (112.2 +/- 8/97.2 +/- 15). Our results suggest that sepsis increases liver protein synthesis, and that this protein synthesis may be enhanced by parenteral nutrition.


Asunto(s)
Infecciones Bacterianas/metabolismo , Hígado/metabolismo , Micosis/metabolismo , Biosíntesis de Proteínas , Animales , Infecciones Bacterianas/terapia , Peso Corporal , Modelos Animales de Enfermedad , Masculino , Micosis/terapia , Nutrición Parenteral Total , Ratas , Ratas Sprague-Dawley
16.
Gut ; 35(1 Suppl): S39-41, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8125388

RESUMEN

The effects of medium chain triglycerides (MCT) on jejunal mucosa mass and protein synthesis were compared with results from previous experiments with rats fed by parenteral nutrition or enteral nutrition. Other published studies have also been analysed. Three experimental models were studied. In the traumatic model, production of a femoral fracture was followed by Kirschner pin insertion into the medullary canal of both fragments at reduction. (Forty ras were fed enteral nutrition and 93 were given parenteral nutrition.) A second model entailed resection under ether anaesthesia using the technique described by Higgins. (Fifty five rats were fed enteral nutrition and 28 with parenteral nutrition.) A third model entailed a terminolateral portocaval shunt under anaesthesia with pentobarbital. (Sixty nine rats were treated this way and then given enteral nutrition.) Proportions of medium chain/long chain triglycerides (LCT) were as follows: 0/100, 20/80, 40/60, 50/50, and 92/8 for enteral nutrition and 0/100, 30/70, 50/50, and 70/30 for parenteral nutrition. Faecal losses of alpha amino nitrogen, protein, total fats, and free fatty acids were analysed together with the quantitative intake, weight gain of the rats, jejunal mucosal mass, and protein synthesis in relation to the MCT proportion ingested or given by enteral nutrition or parenteral nutrition. From analysis of our results and those of others, several conclusions could be drawn. Firstly, the route of administration of MCT is extremely important and enterocytes might be considered one of the main target sites. Secondly, a high proportion of MCT (more than 80%) offers no advantage for jejunal mucosa and produces undesirable side effects. Thirdly, the effect of MCT on jejunal mucosal protein synthesis depends on the metabolic state. Finally, an increase in jejunal mucosal mass directly correlated with MCT concentrations, but no correlation was found between mass and protein synthesis. A positive correlation, however, between MCT proportion and enzyme activity (alkaline phosphatase and sucrase) in the brush border membrane was seen as well as a positive correlation with the concentration of phospholipids in the microvilli.


Asunto(s)
Nutrición Enteral , Mucosa Intestinal/metabolismo , Yeyuno/metabolismo , Biosíntesis de Proteínas , Triglicéridos/metabolismo , Heridas y Lesiones/metabolismo , Animales , Hepatectomía , Modelos Biológicos , Nutrición Parenteral , Ratas , Ratas Sprague-Dawley
17.
Clin Sci (Lond) ; 94(4): 447-52, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9640351

RESUMEN

1. Oxidative damage has been associated with ageing, but there is no agreement as to whether or not it is produced by a decrease in antioxidant defences with the ageing process. In purified lymphocytes from 47 healthy elderly (75.27 +/- 0.91 years) and 47 healthy young (29.87 +/- 0.53 years) volunteers, we studied the levels of antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), protein oxidative damage (as protein carbonyl content) and lysosomal proteolytic activity (cathepsins B, H and L), with and without exposure to oxidative stress produced by 25 mumol/l H2O2. 2. There were no differences in antioxidant enzyme activities in the stressed and non-stressed samples between the young and elderly subjects, indicating that there was no relationship between age and antioxidant enzyme activity even in oxidative stress. However, a dissimilar response to oxidative stress was observed in protein oxidative damage and cathepsin B and L activities, depending on the age of the donor. 3. With these results we conclude that oxidative stress produces greater protein oxidative damage and increased protein degradation in elderly subjects than in young ones; this effect cannot be attributed to dissimilar antioxidant enzyme responses to oxidative stress, since these did not differ between the two age groups.


Asunto(s)
Envejecimiento/fisiología , Endopeptidasas , Peróxido de Hidrógeno/farmacología , Linfocitos/enzimología , Estrés Oxidativo , Adulto , Anciano , Catalasa/metabolismo , Catepsina B/metabolismo , Catepsina H , Catepsina L , Catepsinas/metabolismo , Células Cultivadas , Cisteína Endopeptidasas/metabolismo , Femenino , Glutatión Peroxidasa/metabolismo , Humanos , Linfocitos/metabolismo , Lisosomas/enzimología , Masculino , Proteínas/metabolismo , Superóxido Dismutasa/metabolismo
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