Papers by Mercedes Lombarte
Revista Española de Nutrición Humana y Dietética
Introduction: Sugar-sweetened beverages (SSBs) contain significant amounts of free sugars. SSBs c... more Introduction: Sugar-sweetened beverages (SSBs) contain significant amounts of free sugars. SSBs consumption is strongly associated with overweight/obesity, dental caries, type 2 diabetes mellitus, cardiovascular disease, and other illnesses. The aim of this work was to evaluate the content of free sugars in Argentinian SSBs. Methods: fructose, glucose and sucrose concentrations were measured in 53 samples from carbonated and non-carbonated SSBs through colorimetric techniques; regular (n=26) and low-calorie (n=27) beverages, classified according to nutritional label, were included. The total amount of sugars was calculated and compared with the declared value. Results: regular and low-calorie SSBs differ in their glucose, fructose and sucrose concentrations, but do not differ in their free fructose concentrations. Furthermore, SSBs display higher concentrations of fructose compared to glucose, with a fructose/glucose ratio of 1.45. Conclusions: Regular and low-calorie SSBs differ re...
Journal of Environmental Science and Health, Part C
Abstract The use of fluoride (F) for therapeutic purposes is controversial and its toxicity is a ... more Abstract The use of fluoride (F) for therapeutic purposes is controversial and its toxicity is a health problem. The aim of this study was to evaluate the effect of F on endochondral ossification in growing rats. Twenty-four rats of 21 days were divided into 4 groups which received 0, 20, 40 or 80 μmol F/100 g body weight/day for 30 days, through an orogastric tube. Histological evaluation of growth plate cartilage (GPC) and primary and secondary bone were analyzed on sections of the metaphysis of tibias. Total thickness of the GPC (GPC.Th), thickness of resting zone (RZ.Th), proliferative zone (PZ.Th) and hypertrophic zone (HZ.Th); bone volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), and apoptosis by the TUNEL were measured. A hyperplasia of the proliferative zone and a significant increase in PZ.Th with 40 and 80 μmol F without changes in GPC.Th were found. In the secondary trabecular bone, presence of immature trabeculae, peritrabecular inflammatory foci and sinusoidal dilatation were observed. A significant decrease in BV/TV was also found due to a decrease in Tb.Th and a progressive increase was observed in the number of apoptotic nuclei as the dose of F increased. In conclusion, results suggest that prolonged administration (30 days) of F negatively affect the endochondral ossification with increased chondrocyte proliferation and delayed maturity of new bone, causing inflammatory damage, edema, and increased apoptotic bone cells.
La alta ingesta de fluoruro genera una entidad clínica denominada fluorosis. La Organización Mund... more La alta ingesta de fluoruro genera una entidad clínica denominada fluorosis. La Organización Mundial de la Salud recomienda que el límite para el agua de consumo sea de 1.5 mg /l. Cuando se supera este límite es necesario remediar el agua. La cáscara de huevo es rica en calcio, y podría ser utilizada como un recurso para la disminución de fluoruro de agua, por reacción con el calcio para formar fluoruro de calcio. El objetivo de este trabajo fue desarrollar un método de remediación ecológica para la eliminación de flúor del agua. Se investigaron diferentes variables de este método. 1. Incineración de cáscara de huevo, lo que aumentó 5,6 veces la absorción de fluoruro. 2. Tiempo requerido para completar el 50% del proceso de captación, se obtuvo: 0.52 ± 0.12 min. 3. La captación de fluoruro aumenta significativamente a medida que el tamaño de las partículas disminuye: grueso (1,72±0,55) y fino (1,59±0,30) y ultra fino (2,37±0,35) (ANOVA, test LSD p <0.05). 4. El agua remediada se ...
El ácido zoledrónico (AZ) es el bifosfonato de mayor potencia antirresortiva utilizado para el tr... more El ácido zoledrónico (AZ) es el bifosfonato de mayor potencia antirresortiva utilizado para el tratamiento de la osteoporosis. Sus efectos sobre el hueso trabecular son claros; contrariamente, sus efectos sobre el hueso cortical son motivo de controversia y poco conocidos. El objetivo de este trabajo fue estudiar los efectos del AZ sobre hueso trabecular y cortical de ratas ovariectomizadas (OVX) con osteoporosis. Para ello, 16 ratas Sprague Dawley hembras de 70 días fueron OVX. Ocho ratas fueron sometidas a cirugía simulada (Sham). Luego de 30 días, las ratas OVX recibieron AZ: 0,15 μg/100 g semana (OVX+AZ) o vehículo (OVX) por vía subcutánea. Al mes de tratamiento se determinó la densidad mineral ósea (DMO) de la tibia y, mediante histomorfometría, se evaluó el porcentaje de volumen óseo trabecular (%BV/TV). En el fémur se evaluaron parámetros estructurales corticales y las propiedades mecánicas del hueso cortical y trabecular. Resultados: el AZ incrementó la DMO en 7,71±2,17% vs....
Computer Aided Chemical Engineering, 2013
ABSTRACT As a common laboratory practice rats are studied as biological models for understanding ... more ABSTRACT As a common laboratory practice rats are studied as biological models for understanding several human&#39;s diseases. This work is focused on studying the endocrine behavior to obtain a proper in silico healthy and diabetic rat which would be able to compare well with the experimental data. After this, the expectations are to get valuable insight to quantify the analogies with humans and to determine a realistic scale-up between both, humans and rats. With this purpose the scale-up procedure proposed in Hall et al. [2012] is taken into account. In this context, the well-known model of healthy subject given by Sorensen [1985] was proper to implement the scale-up methodology. Therefore, the main contribution of this work is to present the preliminary procedure of the scale-up focused on the specific problem of diabetes Mellitus. An intensive search in the literature had to be done to perform the simulations. Hence, several results are included and confronted with experimental data. These results will be useful to the pre-clinical testing of control algorithms with rats to be extrapolated to human beings.
Experimental Surgical Models in the Laboratory Rat, 2009
Computers & Chemical Engineering, 2014
ABSTRACT The main contribution of this work is to present a detailed scale-up procedure between h... more ABSTRACT The main contribution of this work is to present a detailed scale-up procedure between human and rats models to more accurately predict what would happen in human beings, based on the experimental results obtained from rats. This procedure begins using the human model, given by Sorensen (1985). The proposed scale-up technique required to establish some assumptions, to do an intensive search in the literature about organs volumes and flow rates of body rats and a dedicated experimental work in the laboratory with these animals. Even though it is mainly focused on studying the endocrine system behavior to obtain a proper in in silico healthy rat it can be extended to study another body regions. Several simulation results with the obtained rat model are included and confronted with experimental data of ten healthy rats. The analogy between human and rat dynamic behavior after equivalent meal intakes are also discussed.
PLoS ONE, 2014
It is known that fluoride produces oxidative stress. Inflammation in bone tissue and an impairmen... more It is known that fluoride produces oxidative stress. Inflammation in bone tissue and an impairment of the respiratory chain of liver have been described in treatments with fluoride. Whether the impairment of the respiratory chain and oxidative stress are related is not known. The aim of this work was to study the effects of fluoride on the production of superoxide radical, the function of the respiratory chain and the increase in oxidative stress in ROS 17/2.8 osteoblastic cells. We measured the effect of fluoride (100 mM) on superoxide production, oxygen consumption, lipid peroxidation and antioxidant enzymes activities of cultured cells following the treatment with fluoride. Fluoride decreased oxygen consumption and increased superoxide production immediately after its addition. Furthermore, chronic treatment with fluoride increased oxidative stress status in osteoblastic cells. These results indicate that fluoride could damage bone tissue by inhibiting the respiratory chain, increasing the production of superoxide radicals and thus of the others reactive oxygen species.
Mathematical Biosciences, 2013
According to the World Health Organization there are over 220 million people in the world with di... more According to the World Health Organization there are over 220 million people in the world with diabetes and 3.4 million people died in 2004 as a consequence of this pathology. Development of an artificial pancreas would allow to restore control of blood glucose by coupling an infusion pump to a continuous glucose sensor in the blood. The design of such a device requires the development and application of mathematical models which represent the gluco-regulatory system. Models developed by other research groups describe very well the gluco-regulatory system but have a large number of mathematical equations and require complex methodologies for the estimation of its parameters. In this work we propose a mathematical model to study the homeostasis of glucose and insulin in healthy rats. The proposed model consists of three differential equations and 8 parameters that describe the variation of: blood glucose concentration, blood insulin concentration and amount of glucose in the intestine. All parameters were obtained by setting functions to the values of glucose and insulin in blood obtained after oral glucose administration. In vivo and in silico validations were performed. Additionally, a qualitative analysis has been done to verify the aforementioned model. We have shown that this model has a single, biologically consistent equilibrium point. This model is a first step in the development of a mathematical model for the type I diabetic rat.
Journal of Endocrinology, 2013
Daily intake of water with fluoride concentrations >1.5 mg/l produces insulin resistance (IR).... more Daily intake of water with fluoride concentrations >1.5 mg/l produces insulin resistance (IR). On the other hand, physical activity increases insulin sensitivity in the muscle. Therefore, the aim of this study was to evaluate the effect of physical activity on IR in rats treated with sodium fluoride (NaF) in drinking water. Sprague–Dawley rats were divided into three groups (n=10/group): Control (drinking water without NaF), NaF (drinking water with NaF 15 mg/l for 30 days), and Exercise (daily running on a treadmill for 60 min at 2.25 m/min and drinking water with NaF 15 mg/l for 30 days). IR was evaluated with the homeostasis model assessment–IR (HOMA–IR) index using fasting plasma levels of glucose and insulin. IR increased in rats treated with 15 mg/l NaF in drinking water. A decrease in IR was observed in rats that performed physical activity and drank water with 15 mg/l NaF; the Exercise group also showed an increase in the amounts of bone fluoride. The variation in the HOM...
Computers & Chemical Engineering, 2013
In this paper, an improved adaptive predictive control with robust filter is developed to be appl... more In this paper, an improved adaptive predictive control with robust filter is developed to be applied in an artificial pancreas. Several problems inherent to endocrine systems for diabetic persons have to be tackled such as nonlinearities, long time delays or daily variations of parameters. Three Finite Impulse Response models for insulin input and the same for meal intake (perturbations) corresponding to normal, hyperhypoglycaemia levels to implement three zones control are taken into account. The glycaemia reference trajectory is shaped from a healthy person response. A variable weighting factor in the cost function is included to prevent dangerous glycaemia excursions out of the allowed limits. Additionally, a noisy blood glucose subcutaneous sensor model is used. This control strategy is tested on 30 virtual subjects from the UVa-Padova Simulator. Simultaneous meals and physiological disturbances are taken into account and the main conclusions are drawn from Control Variability Grid Analysis.
Bone, 2013
were closer than those found for the cortical vBMD in fertile individuals. All relationships were... more were closer than those found for the cortical vBMD in fertile individuals. All relationships were independent of age before menopause, TMP being an additional determinant for both radius and tibia features. Concerning the mechanical influences on the skeleton, the selected mechanical factors (regional muscle size, bone lever lengths) would be more relevant than the selected, age-related or anthropometric determinants or confounders to the determination of the allometrically-associated bone properties (mass, design, strength), yet not to that of bone "intensive" properties as cortical vBMD. Concerning the endocrine-metabolic influences, the mechanical impacts of muscles and bone levers on bone structure were comparable in men and pre-MP women, but TMP could exert a stronger impact than other, allometric or mechanical determinants did on any kind of bone property, including the vCtD, and probably excepting the diaphyseal design.
Bone, 2011
s from the XXVII Annual Meeting of the Argentine Association of Osteology and Mineral Metabolism ... more s from the XXVII Annual Meeting of the Argentine Association of Osteology and Mineral Metabolism 9-11th September 2010 Cordoba, Argentina Role of intestinal alkaline phosphatase (IAP) in calcium (Ca) absorption L.R. Brun, L. Arias, M. Alonso, C. Guglielmi, A. Rigalli Bone Biology Laboratory, Rosario, Argentina E-mail address: lbrun@unr.edu.ar The association of IAP with Ca absorption is partially known. Previous experiments indicated that Ca binds to IAP, contributes to maintain the active structure and increases the activity of membrane-bound form. There is evidence that the decrease in pH alters the TRPV6-Ca channel activity. The aim of this study was to evaluate the effect of pH and phosphate generated by the action of the IAP on Ca absorption. Experiments were carried out with everted duodenal sacs. The intestinal mucosa was exposed to a buffer with Ca 1, 10, 50 or 100 mM, pH 9 and the serosa to the same solution without Ca (n=4/group). Phosphorus (P), Ca and pH were measured in the mucosa solution at 0, 10 and 20 min. Ca absorption was calculated by the difference between Ca concentration at 0 and 20 min. The precipitation of Ca phosphate was calculated with pH, P and Ca. Experiments were also carried out in the presence of phenylalanine (Phe), an inhibitor of the IAP. As Ca increased in the solution, there was a significant decrease in Ca absorption (Ca 1: 45±4; Ca 10: 42±11; Ca 50: 38±11; Ca 100: 30±11) and a significant decrease of pH (Ca 1: 7.8±0.1; Ca 10: 7.4± 0.1; Ca 50: 6.9±0.2; Ca 100: 6.9±0.1). Precipitation as Ca phosphate was negligible, and it was not responsible for the decrease in Ca absorption. When the experiments were carried out in the presence of Phe there was an increase in Ca absorption (Ca 1: 53±5; Ca 10: 56± 6; Ca 50: 42±10; Ca 100: 40±6) with a decrease in pH not as evident as in the absence of Phe (Ca 1: 8.33±0.15; Ca 10: 8.05±0.18; Ca 50: 8.17±0.17; Ca 100: 8.28±0.21). These results support the hypothesis that pH regulates the entry of Ca to the enterocyte and acts as a sensor of luminal Ca. This article is part of a Special Issue entitled AAOMM 2010 Abstracts. doi:10.1016/j.bone.2011.03.722 Effect of fluoride on oxygen consumption (OC) by rat tissues B.L. Fina, A. Rigalli Bone Biology Laboratory, Rosario, Argentina E-mail address: arigalli@unr.edu.ar Fluoride (F) enters the body through food, treatments for bone loss or prevention of dental caries. It has a positive effect on bone formation, but it can affect the oxidative stress. Previous reports have been performed usually with F concentrations higher than those found in vivo. The aim of this study was to evaluate the effect of F on OC with F concentrations similar to those in plasma after a dose for osteoporosis treatment or after the consumption of fluoridated water. OC was measured in slices of liver, kidney and muscle with F 0–100 μM. Sprague–Dawley rats were divided into three groups: Control (C), Treated with F (TF): 15 ppm F in drinking water for 30 days (model of caries prevention) and MFP: ovariectomized rats treated with monofluorophosphate 80 μmol/day for 60 days (model of osteoporosis treatment). After euthanasia, slices of tissues were successively exposed to 0, 10, 50 and 100 μM F. The presence of F decreased OC in liver and muscle in all groups. The opposite was observed in kidney. OC consumption is shown as nmol/min·mg protein, mean±SEM. Muscle, 10, 50 μM not shown. *p<0.05 significant difference from 0 μM. Liver: C (0 μM: 15.7±2.5; 100 μM: 10.5±2.2*); TF (0 μM: 14.9±1.5; 100 μM: 9.4±1.1*); MFP (0 μM: 13.1±0.9; 100 μM: 10.2±0.8*). Kidney: C (0 μM: 18.2±1.2; 100 μM: 31.9±2.5*); TF (0 μM: 14.0±1.8; 100 μM: 29.0±5.2*); MFP (0 μM: 18.6±2.0; 100 μM: 32.0±3.0*). Transaminase and creatine kinase activity, creatinine clearance and histological study did not show significant changes in tissues at the beginning of the measurements. Conclusion: F produces changes in OC at concentrations comparable to those found in vivo. These results would indicate that the modification of oxidative stress could be due to changes in the production of reactive oxygen species at the level of the respiratory chain. This article is part of a Special Issue entitled AAOMM 2010 Abstracts. doi:10.1016/j.bone.2011.03.723 Clinical, molecular and bone metabolism studies in patients with Congenital Adrenal Hyperplasia S. Martin, L. Munoz, A. Perez, G. Sobrero, G. Picotto, M. Ochetti, A. Carpentieri, L. Silvano, G. Diaz de Barboza, M. Signorino, C. Ruperez, P. Bertolotto, M.R. Ulla, N. Tolosa de Talamoni, M. Miras Servicio de Endocrinologia Hospital de Ninos, Catedra de Bioquimica y Biologia Molecular FCM-UNC, FAMAF-UNC, CEOM Cordoba, Argentina We investigated final height and clinical and biochemical indicators of the outcome of glucocorticoid therapy in patients with different clinical forms of Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency. The frequencies of polymorphisms of different genes and their associations with…
Centro de Endocrinología, Dec 1, 2014
As a common laboratory practice rats are studied as biological models for understanding several h... more As a common laboratory practice rats are studied as biological models for understanding several human’s diseases. However, only few works propose a methodology for quantifying the analogies between both species. This work presents a systematic procedure to construct efficient models to predict more accurately what would happen in human beings based on the experimental results obtained from rats. In this context, the well-known model of healthy subjects given by Sorensen et al. (1985) was adequate to implement the scale-up methodology based on some assumptions given by Hall et al. (2012). Therefore, the main contribution of this work is to present the detailed scale-up procedure which needed to do an extensive search on the literature to adapt the human model to the rat model. It is expected that this validated rats model could be useful for testing diets, physical exercises effects, drugs delivery, pharmacokinetics studies for then extrapolate conclusions for human beings.
En la parte superior del recuadro verá la posibilidad de descargarlo para Linux, Mac o Windows. H... more En la parte superior del recuadro verá la posibilidad de descargarlo para Linux, Mac o Windows. Haga click allí y siga las instrucciones. Una vez que lo haya logrado instalar, recomendamos seguir y ejecutar los comandos planteados en esta clase, con el fin de familiarizarse son el entorno. 1.1.1. Instalación en linux 1.1.1.1. Desde consola puede hacerlo desde la consola. Para ello abra la consola y escriba los siguientes códigos, habiendo accedido a la misma como usuario root. Primero actualice los paquetes de su distribución sudo apt-get update luego intale R con la siguiente línea. sudo apt-get install r-base 1.1.1.2. Desde el software center En la distribución ubuntu puede hallar la interfaz R-commander. No la utilizaremos en este curso, pero es compatible con el mismo. En este curso trabajaremos desde la consola que es similar a la interfaz utilizada en windows. 1.1.1.3. Desde Synaptic Package Manager Busque el paquete r-base-core, selecciónelo e instálelo. 1.1.2. Instalación desde windows. Al momento de instalar R en una computadora que posea como sistema operativo a Windows es necesario en primera medida bajar el programa con la ayuda de cualquier navegador instalado en la misma. En mi caso el que utilizo habitualmente es chrome, desde el buscador preferido (google en este caso) colocando R o bien "the R project" nos encontrará el sitio donde encontraremos el software. Si observamos encontramos entre las opciones que nos remite a "R para Windows", que nos lleva directamente a los links deseados o bien podemos ingresar a la pagina "the R project" donde encontraremos una breve descripción de que es R, noticias sobre el mismo e incluidas allí las últimas versiones de R que se encuentran aptas para su instalación y uso. Cliqueando en algún link de las versiones de R (R se actualiza periódicamente y la última
The fluoride ion (F) is a disturbing substance for the glucose-insulin system. The effects of F h... more The fluoride ion (F) is a disturbing substance for the glucose-insulin system. The effects of F have been studied in various aspects. The chronic intake of F generates hyperglycaemia with high plasma insulin levels. This effect is observed in several countries where the content of fluoride in drinking water is greater than the upper limit recommended by WHO (1.5 mg/L). The administration of a dose of F causes a decrease of insulin levels, which was attributed to a decrease in insulin secretion through in vitro experiments. However, measurement of insulin secretion in vivo has not been done so far. Moreover, in endemic fluorosis areas children had lower intelligence quotient (IQ) than children of areas with low F in drinking water. This decrease in IQ has also been observed in rats. In this work, the glucose uptake rate of insulin-independent tissues, insulin secretion, and insulin clearances were measured in vivo in rats that received a dose of F. A lower secretion and clearance of ...
A previous methodology was developed in order to measure bone remodelling in rats by the retentio... more A previous methodology was developed in order to measure bone remodelling in rats by the retention of fluoride. This technique has some advantages in comparison to bone remodelling markers: bone formation and bone resorption can be measured simultaneously and it is a low cost technique. However, it has several disadvantages such as, anaesthesia, blood samples, multiple urinary samples collection and intravenous fluoride dose. Consequently that technique was not useful for bone remodelling measurement in human beings, because intravenous injection of fluoride is not advisable in humans. However, as fluoride pharmacokinetic has been exhaustively studied in humans and rats, a modification at the mentioned technique was done to avoid intravenous injection of fluoride and to overcome the mentioned disadvantages. The simplification of the previous method has several advantages such as: administration of an oral dose of fluoride, two urinary samples, the simultaneous measurement of both pr...
Tabla de datos para la clase 8 del modulo 4 del curso Uso de herramientas informaticas para la re... more Tabla de datos para la clase 8 del modulo 4 del curso Uso de herramientas informaticas para la recopilacion, analisis e interpretacion de datos de interes en las ciencias biomedicas.
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Papers by Mercedes Lombarte