Carmen Gloria González

Comparative studies on glucose phosphorylating isoenzymes of vertebrates—I. The influence of fasting and the nature of the diet on liver glucokinase and hexokinases of rodents☆

Abstract 1. 1. Glucose phosphorylating activities were measured in liver extracts from rat, mouse, hamster guinea pig and degu. The high- K m isoenzyme (glucokinase) was distinguished from the low- K m isoenzymes (hexokinases) by performing the assays at two levels of glucose. 2. 2. Total glucose phosphorylating activities varied widely in the various species. However, glucokinase was always the predominant form. The ratio glucokinase/hexokinases was the highest in the hamster, due to a very low level of hexokinases. The lowest ratio was found in the guinea pig, because of a low level of glucokinase. 3. 3. Fasting induced a decrease of glucokinase in the rat, mouse and hamster, but not in the guinea pig and degu. Hexokinase levels on the contrary were not significantly modified by this treatment. 4. 4. Feeding a carbohydrate-free diet (high fat, high protein) did not affect the glucokinase level in BALB mice, and moderately lowered the levels in the C 57 BL strain. Feeding a carbohydrate diet (carbohydrate as the sole source of calories) reduced glucokinase in both strains. The administration of glucose, however, restored totally (BALB mice) or partially (C 57 BL mice) the enzyme activities lowered by fasting. Glucose also restored normal levels of glucokinase in C 57 BL mice fed a carbohydrate-free diet. 5. 5. Feeding the carbohydrate diet caused a significant increase of the levels of hexokinases in both strains of mice. A similar effect was observed in C 57 BL mice fed the carbohydrate-free diet.

Comparative studies on glucose phosphorylating isoenzymes of vertebrates—II. Chromatographic patterns of glucokinase and hexokinases in the liver of rodents

Abstract 1. 1. Four isoenzymes (A, B, C, D) catalyzing the phosphorylation of glucose were resolved by DEAE-cellulose column chromatography from the liver of rat, mouse, hamster, guinea pig and degu. The chromatographic mobility of peak D (glucokinase) was rather constant within different species. The mobilities of peaks A, B and C (hexokinases) varied widely. 2. 2. According to the order of elution, two patterns were distinguished. The rat type, defined by the elution sequence A, B, C, D, was present in the rat and degu. The mouse type, with the elution sequence A,C, B, D, was found in the mouse, hamster and guinea pig. The identification of the chromatograhic peaks was made mainly through the K m glucose values and the typical inhibition by excess substrate of isoenzyme C. 3. 3. Glucokinase was the predominant isoenzyme in all the species studied. It was markedly decreased by fasting in the rat, hamster and mouse, whereas apparently it was not affected in the guinea pig and degu. 4. ]4. Fasting did not change significantly the amount of the hexokinase isoenzymes in the animals studied. In the fasted guinea pig isoenzyme C was not inhibited by excess substrate.

Isolation and partial characterization of three DNA polymerases from Trypanosoma cruzi

Three distinct DNA polymerase fractions (A, B and C), were isolated from Trypanosoma cruzi epimastigote forms. Fraction A is a low molecular mass enzyme corresponding to beta-like DNA polymerase of T. cruzi. Fraction B co-purified along several purification steps with fraction A, but in the last step it was clearly separated by a phosphocellulose chromatography. Fraction C was separated from fractions A and B by binding to DEAE-cellulose column, since the other two fractions were eluted in the flowthrough. This enzyme has an apparent native molecular mass of 100 kDa and showed a high preference for poly(dC)-oligo(dG) among different template-primers tested as substrate. Western-blot and biochemical analysis strongly suggest that the three DNA polymerase fractions correspond to different molecular entities. These results are in agreement with the idea that fraction C is a new DNA polymerase of T. cruzi, not described before.

Estilos de vida, alimentación y estado nutricional en trabajadores de la construcción de la Región Metropolitana de Chile

BACKGROUND The less affluent and educated members of the society tend to be less prone to healthy lifestyles. AIM To describe feeding habits, nutrition, quality of life and working conditions of construction workers comparing two recent surveys, namely the 2009 Chilean National Health Survey (NHS) and the 2010 Work, Employment and Health Survey (WEH). MATERIAL AND METHODS One hundred ninety male workers aged 43±13 years were surveyed about feeding habits during working days and weekends, smoking and usual physical activity. Weight, height and blood pressure were also measured. RESULTS In 2010, 82% of workers were overweight or obese compared with 67% rates in the NHS of 2009. The rate of sedentariness was 86% compared with 84% in the NHS of 2009 and 93% in the WEH 2010. Forty one percent smoked and those aged less than 25 years consumed more calories than the other age groups. There was a high intake of carbonated beverages, bread, salted and red meats and a low consumption of fruits, vegetables, legumes and fish. Seventy seven percent had a meal at midafternoon and only 25% ate supper. Lunch had a fixed schedule, was considered good and usually was prepared by a family member. The level of satisfaction with work, family life and life in general was high. The satisfaction with health and physical condition was lower. CONCLUSIONS The unhealthy lifestyles of these construction workers should alert health authorities.

Motivaciones y barreras de los niños chilenos: ¿amenazas u oportunidades para la implementación de las guías alimentarias 2013?

INTRODUCTION Implementation of the updated Food Based Dietary Guidelines (FBDG) for the Chilean population requires the design of innovative strategies and effective. OBJECTIVE To determine motivations and barriers for children and mothers of preschool-age children to follow new FBDG messages, aiming to identify challenges and opportunities for designing effective communication and implementation strategies. METHODS A qualitative study based on 12 focus groups of 9 to 13 age children and 6 focus groups of mothers of preschool-age children, living in the north, central and south regions of the country, to analyze their reaction to each one of the 2013 FBDG messages. RESULTS AND DISCUSSION Answers of children and mothers did not show differences by gender (in the case of the children) or region of the country. Results show the most frequent and representative comments regarding each message. Challenges to reducing the consumption of foods high in energy, fat, sugar and salt include advertisements and plentiful supply and low prices for these types of foods, both in the school environment and on the street. Opportunities identified included the advertisement of fruits, vegetables and dairy products to promote their consumption, as well as the coming implementation of Law 20.606, which is expected to be an effective way to support this initiative. CONCLUSION The results of this study show that the design of strategies based on values, desires and needs of different groups will contribute to optimizing the implementation of the 2013 Chilean FBDG.

Evaluación de una intervención educativa nutricional en trabajadores de la construcción para prevenir enfermedades crónicas no transmisibles en Chile

BACKGROUND Unhealthy lifestyles and overweight are common among blue collar workers. AIM To evaluate a nutrition education intervention in construction workers to prevent chronic diseases. MATERIAL AND METHODS One hundred forty two participants were randomly assigned to an experimental group (n = 69) and or a control group (n = 73). The experimental group received nutrition education consisting in individual lifestyle counseling, group workshop, group counseling in healthy lifestyles, and environmental intervention. At baseline and after one year of intervention, clinical evaluations consisting in laboratory determinations, anthropometry and nutritional assessment evaluation were carried out. RESULTS The experimental group experienced a significant decrease in waist circumference, total cholesterol, triglycerides, and an increase in HDL cholesterol. A significant reduction in total calorie intake, especially at the evening snack was observed during week-days. The same reduction in total calories occurred at dinner during the week-end. A significant increase was observed in the consumption of fruits, vegetables and fish. In the control group there was a significant increase in weight, waist circumference, body mass index, glucose and insulin, without changes in total calorie intake or healthy food consumption. High soft drink consumption did not change in both groups. CONCLUSIONS In construction workers, integral nutrition intervention at the individual, group and environmental level had an impact in nutritional and biochemical indicators.Background: Unhealthy lifestyles and overweight are common among blue collar workers Aim: To evaluate a nutrition education intervention in construction workers to prevent chronic diseases. Material and Methods: One hundred forty two participants were randomly assigned to an experimental group (n=69) and or a control group (n=73). The experimental group received nutrition education consisting in individual lifestyle counseling, group workshop, group counseling in healthy lifestyles, and environmental intervention. At baseline and after one year of intervention, clinical evaluations consisting in laboratory determinations, anthropometry and nutritional assessment evaluation were carried out. Results: The experimental group experienced a significant decrease in waist circumference, total cholesterol, triglycerides, and an increase in HDL cholesterol. A significant reduction in total calorie intake, especially at the evening snack was observed during week-days. The same reduction in total calories occurred at dinner during the week-end. A significant increase was observed in the consumption of fruits, vegetables and fish. In the control group there was a significant increase in weight, waist circumference, body mass index, glucose and insulin, without changes in total calorie intake or healthy food consumption. High soft drink consumption did not change in both groups. Conclusions: In construction workers, integral nutrition intervention at the individual, group and environmental level had an impact in nutritional and biochemical indicators.

Diseño y validación de la imagen para la difusión e implementación de las guías alimentarias para la población chilena

INTRODUCTION Food-Based Dietary Guidelines (FBDG) are usually accompanied by an image for dissemination and implementation. OBJECTIVE to design and validate an image to represent the variety and proportions of the new Chilean dietary guidelines, include foods high in critical nutrients that should be avoided and physical activity guidelines. METHOD a panel of experts tested seven graphics and selected three that were validated with 12 focus groups of people aged 10-14 and 20-40 years, of both sexes, from different socioeconomic groups and from both rural and urban areas. We analyzed the perception of variety and proportions of the food groups for daily intake and motivation for action in diet and physical activity. We utilized the METAPLAN method used previously in the validation of FBDG. RESULTS AND DISCUSSION the final image was a circle that showed the variety and proportions of each food group for daily consumption (in pictures), included physical activity guidelines in a strip around the middle of the circle and a rectangle towards of bottom of the image with examples of foods high in critical nutrients in black and white. The chosen picture was modified using input from participants and validated with three additional focus groups, improving its understanding and acceptance. CONCLUSION most participants understood that the image represented the relationship between healthy eating and daily physical activity, correctly identifying the food groups for which increased intake was suggested and those groups in which intake should be reduced or avoided.

Validación de un instrumento para evaluar consumo, hábitos y prácticas alimentarias en escolares de 8 a 11 años

INTRODUCTION An instrument to measure food knowledge, food consumption, cooking skills, food habits and food expenses at school is necessary to assess changes in food practices. OBJECTIVE To validate an instrument to measure changes in food knowledge, food consumption, cooking skills, food habits and food expenses in Chilean school children 8 - 11 years from third to fifth grade. METHODS A validation of a questionnaire with 42 questions was conducted in two stages: the first to assess temporal stability, concordance and internal consistency in 45 children. The second one to apply the survey, modified with the results of the first stage, in 90 children assessing internal consistency. RESULTS The first survey with 42 questions showed a reasonable temporal stability, concordance and internal consistency for cooking skills, habits and food expenditure at school. Internal consistency was good for food consumption, but not so good for food knowledge. In the final validation with 90 children, there was good consistency for food consumption but bad for food knowledge. Besides, children with cooking skills ate more healthy food and those who expended more money at school, consumed less healthy food. CONCLUSIONS Food knowledge questions were eliminated from the instrument, which was elaborated with 28 questions about food consumption, cooking skills, food habits and food expenses at school. This instrument is useful to assess changes in food and nutrition education interventions in 8 -11 years children, in particular to measure cooking skills and food expenses at school.

Influence of glycogen content on the effect of 2,4-dinitrophenol on the synthesis of p-aminohippurate by rat liver slices☆

Abstract The effect of 2,4-dinitrophenol (DNP) on the synthesis of p -aminohippurate (PAH) by rat liver slices under several experimental conditions was studied. A concentration of 0.025 m M DNP inhibits PAH synthesis, and this effect is less pronounced with high glycogen content in the tissue. Fructose 1,6-diphosphate and pyruvate also counteract partially the inhibitory effect of DNP in slices with low glycogen content. At higher concentrations of DNP (0.1 m M ), high glycogen content still protects PAH synthesis; fructose 1,6-diphosphate protects only if glycogen level is high and pyruvate exerts no significant protection. The anaerobic suppression of PAH synthesis is counteracted neither by high glycogen content nor by addition of fructose 1,6-diphosphate and pyruvate. Exogenous adenosine triphosphate (ATP) does not protect against DNP. Moreover, ATP by itself inhibits the synthesis of PAH.

Teachers' self-perception of their dietary behavior and needs to teach healthy eating habits in the school.

Through focus groups, we explored 22 third- to fifth-grade teachers’ perceptions about their eating habits, including barriers and facilitators to healthy eating. It also explored teachers’ thoughts about how to teach students healthy eating habits. The information was transcribed and treated using the content analysis technique. Results were evaluated using the concept of majority and minority group and presented in a sequential way: teachers’ perceptions about eating habits, barriers to healthy eating, teacher’s culinary habits, abilities to teach students healthy eating habits through Information and Communication Technologies, and cooking activities. Teachers’ eating habits were poor, with lack of time, money, and will to improve. They had culinary habits skills and the desire to instruct and guide their students in eating healthier food. They need a program with Information and Communication Technologies and cooking workshops to apply in the classroom.