RESUMEN
Diabetes mellitus is a group of metabolic disorders, the incidence of which varies widely throughout the world. The treatment of diabetes mellitus includes insulin, oral antidiabetic agents, and dietary regimens. Although the emphasis is on macronutrients intakes, there is strong evidence that there is an abnormal metabolism of several micronutrients in diabetic individuals. Zinc is one of the essential micronutrients of which status and metabolism is altered in this condition. This work is a short review about the close relation among zinc, glucose metabolism, and insulin physiology, as well as about the few experimental data about zinc absorption and zinc supplementation in diabetes mellitus patients.
Asunto(s)
Diabetes Mellitus/sangre , Diabetes Mellitus/tratamiento farmacológico , Zinc/farmacología , Complicaciones de la Diabetes , Suplementos Dietéticos , Radicales Libres , Glucosa/metabolismo , Humanos , Insulina/metabolismoRESUMEN
Microencapsulated ferrous sulfate with soy lecithin (SFE-171) has been used as an iron source for the fortification of milk and dairy products. With the purpose to extend the use of this agent to other kind of foods or even to pharmaceutical preparations for oral administration, the SFE-171 was turned into a fluid powder (SFE-171-P) by means of vacuum drying. The iron bioavailability (BioFe) of SFE-171-P was evaluated in this work by means of the prophylactic-preventive method in rats, using ferrous sulfate as reference standard. Both iron sources were separately added to a basal diet of low iron content in a concentration of 10 mg iron/kg diet. Two groups of 10 weaned rats 25 days old received the fortified diets during 28 days, while a third group of the same size received the basal diet without iron additions. The weights and haemoglobin concentrations (HbC) of every animal were determined before and after the treatment, thus allowing the calculation of the mass of iron incorporated into haemoglobin (HbFe) during this period. The BioFe of the iron sources were obtained as the percentage ratio between the HbFe and the mass of iron consumed by each animal. The results were also given as Relative Biological Value (RBV), which relates the BioFe of the studied source with that of the reference standard. The liver iron concentration (LIC) of each animal was determined at the end of the experiment in order to evaLuate the influence of the studied iron sources on the liver iron stores. SFE-171-P presented BioFe, RBV and LIC values of (47 +/- 7)%, 109% and (46.6 +/- 3.4) mg/kg respectively, while the corresponding values for the reference standard were of (43 +/- 7)%, 100% and (45.0 +/- 4.7) mg/kg. These results show that the drying process used to produce the SFE-171-P does not affect its bioavailability, which is also adequate for the potential use of this product in food fortification or with pharmaceutical purposes.
Asunto(s)
Compuestos Ferrosos/farmacocinética , Hierro/farmacocinética , Fosfatidilcolinas/farmacocinética , Animales , Química Clínica/métodos , Suplementos Dietéticos , Relación Dosis-Respuesta a Droga , Composición de Medicamentos , Femenino , Hemoglobinas/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
Food fortification with a proper zinc compound is an economic and effective strategy to prevent zinc deficiency. BioZn-AAS, a zinc gluconate stabilized with glycine, was compared with zinc sulfate (reference standard), zinc hydroxide, and zinc gluconate, all of them labeled with (65)Zn. This preclinical study was performed on Sprague-Dawley rats of both sexes, and the administered dose was 85 microg/kg of zinc. Bioavailability studies showed that absorption of BioZn-AAS was not statistically different than absorption from other sources in female rats (25.65% +/- 2.20% for BioZn-AAS, 28.24% +/- 4. 60% for ZnSO(4), 24.91% +/- 4.02% for Zn[OH](2), and 25.51% +/- 2. 70% for Zn-gluconate). In the case of the male rats, absorption of BioZn-AAS (27.97% +/- 4.20%) was higher (P<0.05) than that from the other compounds (23.15% +/- 2.90% for ZnSO(4), 22.62% +/- 3.90% for Zn[OH](2), and 22.30% +/- 3.90% for Zn-gluconate). Biodistribution studies demonstrated that the zinc from BioZn-AAS followed the same metabolic pathway as zinc from the other sources. Toxicity studies were performed with 50 female and 50 male rats. The value of oral lethal dose 50 (LD(50)) was 2000 mg/kg for female rats and 1900 mg/kg for male rats. Therefore, we conclude that BioZn-AAS has adequate properties to be considered a proper zinc compound for food fortification or dietary supplementation.
Asunto(s)
Especificidad de Órganos , Compuestos de Zinc/farmacocinética , Compuestos de Zinc/toxicidad , Absorción , Animales , Disponibilidad Biológica , Femenino , Gluconatos/farmacocinética , Hidróxidos/farmacocinética , Dosificación Letal Mediana , Masculino , Ratas , Ratas Sprague-Dawley , Sulfato de Zinc/farmacocinéticaRESUMEN
Radio-iron tests are frequently used to measure the bioavailability of different iron sources for food fortification. As the labeling procedures must be done under laboratory conditions, complementary studies should be carried out to evaluate the bioavailability of iron sources produced on an industrial scale. The iron bioavailability of SFE-171 (ferrous sulfate microencapsulated with phospholipids) was studied in previous reports using the compounds labeled with 59Fe and 55Fe; the results showed an iron bioavailability similar to that of ferrous sulfate. In the present work, the iron bioavailability of industrial SFE-171 was studied by the prophylactic-preventive method in rats using ferrous sulfate as the reference standard. Elemental iron powder was also studied by the same method for comparative purposes. The liver iron concentration of each animal was determined at the end of the experiment in order to evaluate the influence of each iron source on the liver iron stores. Relative biological values of 98 and 34% were found for SFE-171 and elemental iron powder, respectively, while the corresponding relative liver iron concentrations were 104 and 45%. The results provided by the prophylactic-preventive method show that the iron bioavailability of industrial SFE-171 is similar to that of ferrous sulfate; these results are also in agreement to those obtained with the radioactive compounds. We can conclude that the SFE-171 obtained by industrial procedures for massive use in iron food fortification has the same bioavailability as that of the SFE-171 produced and labeled under laboratory conditions.
Asunto(s)
Compuestos Ferrosos/farmacocinética , Absorción Intestinal , Hierro/metabolismo , Animales , Disponibilidad Biológica , Composición de Medicamentos , Compuestos Ferrosos/administración & dosificación , Alimentos Fortificados , Hierro/administración & dosificación , Hígado/química , Hígado/metabolismo , Masculino , Fosfolípidos , Ratas , Ratas Sprague-Dawley , Estándares de ReferenciaRESUMEN
Among the many examples of neuroendocrine-immune system interactions the relationship between the thyroid axis and the immune function has yet to be clearly established. Here we studied the influence of thyroid hormones on the course of an alloimmune response. Murine T(3) and T(4) levels were found to be increased a few days after the immunization of mice with allogeneic lymphoid cells. Besides in vivo treatment with T(4) was shown to increase alloantibody titers during the early stages of alloimmunization and to enforce lymphoid proliferation in vitro in a mixed lymphocyte reaction. Conversely, lowering thyroid hormone seric levels by propylthiouracil treatment, negatively modulates the humoral and cellular alloimmune responses. The evidence here points to the existence of a bidirectional communication between both systems. The possibility that the antigenic challenge would increase the thyroid gland activity thus leading to a positive modulatory action upon the immune response is also discussed.
Asunto(s)
Sistema Inmunológico/fisiología , Sistemas Neurosecretores/inmunología , Glándula Tiroides/inmunología , Animales , Femenino , Isoanticuerpos/biosíntesis , Prueba de Cultivo Mixto de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Tiroxina/sangre , Triyodotironina/sangreRESUMEN
UNLABELLED: Exogenous natural surfactant (ENS) labeled with 99mTc(99mTc-ENS) is a new radiopharmaceutical for pulmonary aerosol scintigraphy. In this study, different freeze-dried formulations were evaluated to develop a suitable and long-storage method for the ENS, the nonradioactive precursor of this radiopharmaceutical. METHODS: Two freeze-dried formulations were evaluated: the sterile ENS suspension-stannous chloride altogether lyophilized (chlorlioENS) and the lyophilized sterile ENS suspension with the addition of stannous chloride as a solid drug (lioENS). These precursors were stored at room temperature for 3 mo and then labeled with 99mTc. For comparative purposes, the sterile ENS suspension with the addition of stannous chloride labeled with 99mTc(99mTc-chlorENS) was also studied. The quality controls for each radiopharmaceutical were performed by an ascending paper chromatography to determine the labeling yield percentages. The study was performed in 30 female Sprague Dawley rats, which inhaled each radiopharmaceutical by nebulization. Twenty-five minutes after the aerosol inhalation, the animals were killed to extract their organs and measure their activity in a gamma spectrometer. The data are given as the percentage of activity concentration (C%) for each organ. RESULTS: The physicochemical properties of lioENS were adequate for a freeze-dried product. The labeling yields for 99mTc-lioENS and for 99mTc-chlorENS were always greater than 95% even after nebulization. The results of the biologic distribution studies showed that the activity concentration found in lungs for these radiopharmaceuticals were 95.7% +/- 2.6% and 96.7% +/- 2.6% respectively, results that do not differ statistically. On the other hand, the activity concentration found in lungs for the 99mTc-chlorlioENS (31.3% +/- 11.1%) and its labeling yield percentages (<10%) are statistically different (P < 0.05) from the results obtained with the two radiopharmaceuticals mentioned above. CONCLUSION: Taking into account the lioENS physicochemical properties, its long shelf life and that 99mTc-lioENS shows the same radiochemical and radiopharmacological behavior of the 99mTc-chlorENS, it can be concluded that the 99mTc-lioENS can be used for aerosol lung scintigraphy.
Asunto(s)
Pulmón/diagnóstico por imagen , Surfactantes Pulmonares , Radiofármacos , Tecnecio , Aerosoles , Animales , Interpretación Estadística de Datos , Femenino , Liofilización , Riñón/metabolismo , Hígado/metabolismo , Pulmón/metabolismo , Surfactantes Pulmonares/farmacocinética , Surfactantes Pulmonares/normas , Control de Calidad , Cintigrafía , Radiofármacos/farmacocinética , Ratas , Ratas Sprague-Dawley , Bazo/metabolismo , Tecnecio/farmacocinética , Tecnecio/normasRESUMEN
To determine the absorption and biodistribution of iron from microencapsulated ferrous sulfate (SFE-171), used to fortify dairy products with iron, a comparative study in four groups of 30 mice each was carried out. In two of the groups, the absorption of iron from ferrous ascorbate in water (13.3 +/- 4.3%) and from ferrous sulfate in water (12.7 +/- 3.9%) was determined and taken as reference standards. In the third group the iron absorption from SFE-171 in milk was determined, giving a value of 12.1 +/- 4.2%, which statistically does not differ from the data obtained with either reference standard. In the fourth group, the absorption of iron from ferrous sulfate in milk showed a value of 7.7 +/- 3.4%, which statistically differs with a p < 0.01 from the data corresponding to the other three groups. The biodistribution studies showed that the iron from the SFE-171 follows the same metabolic pathway as the iron from the reference standards thus, giving a higher radioactivity percentage and radioactivity concentration in organs or systems, principally blood, that are closely related to iron metabolism. Our studies allow us to conclude that the iron from SFE-171 in milk follows the same behavior as the nonhemic iron, with a higher absorption than that of ferrous sulfate in milk.
Asunto(s)
Compuestos Ferrosos/administración & dosificación , Compuestos Ferrosos/farmacocinética , Alimentos Fortificados , Leche , Absorción , Animales , Huesos/metabolismo , Composición de Medicamentos , Femenino , Hígado/metabolismo , Ratones , Músculos/metabolismo , Piel/metabolismo , Distribución TisularRESUMEN
The iron compounds used for food fortification have to meet certain requisites related to their bioavailability, absorption mechanism, and toxicity, since they will be consumed by a massive population group. With these purposes, we evaluated a new product used for the iron fortification of milk and lacteous derivatives, called SFE-171, which is a ferrous sulfate, microencapsulated with phospholipids. The bioavailability studies were carried out using four groups of 30 female mice each. In two groups, we studied the absorption of ferrous ascorbate and ferrous sulfate, both in water as reference standards, which show absorptions of 13.1+/-4.9% and 13.2+/-4.3%, respectively. With the third group, we studied the absorption of ferrous sulfate in milk; its value, 7.9+/-3.2%, is significantly lower than that of the remaining groups, with a p < 0.01. The studies with SFE-171 in milk, were performed on the fourth group, with a result of 11.6+/-4.5%, demonstrating that its absorption does not differ significantly from that of the reference standards. The absorption mechanism was determined by means of in vivo self-displacement studies of the ferrous ion and the SFE-171, taking ferrous sulfate as the reference compound. For this study, 210 female mice were used, and no significant difference between the absorption mechanism of both products could be observed. Toxicity studies of the new product with regard to ferrous sulfate were carried out with two groups of 70 female mice each and two groups of 70 male mice each. The lethal dose 50% LD50 for SFE-171 and for ferrous sulfate was 1200 and 680 mg/kg for female mice and 1230 and 670 mg/kg for male mice, respectively, demonstrating that the toxicity of the first product is substantially lower than that of the reference standard. We conclude that the iron product under study has a high bioavailability, an absorption mechanism equal to that of nonhemic iron, and lower toxicity than ferrous sulfate.
Asunto(s)
Compuestos Ferrosos/farmacocinética , Análisis de Varianza , Animales , Disponibilidad Biológica , Composición de Medicamentos , Femenino , Compuestos Ferrosos/administración & dosificación , Compuestos Ferrosos/toxicidad , Absorción Intestinal , Dosificación Letal Mediana , Masculino , RatonesRESUMEN
The purpose of this work is to study the physicochemical properties of Pirocarbotrat to explain its radiopharmacological behavior. We also studied a mixture of charcoal plus chromic [32P]phosphate and charcoal plus sodium [32P]orthophosphate only for comparative purposes. The results show that the mean diameter of the Pirocarbotrat particles was 2.5 microm with an homogeneous distribution, while the other products show an heterogeneous distribution of the particle sizes, with a mean size diameter between 0.5 and 0.9 microm. Hydrolysis studies with a solution of 0.1 N HCl and with sulfochromic mixture revealed that in Pirocarbotrat the 32P is strongly bound to the charcoal particles. Bioelimination studies of Pirocarbotrat show that the total eliminated activity was 12.70 +/- 3.90%, with a higher amount in urine (8.30 +/- 1.80%) than in feces (4.40 +/- 3.50%). When biodistribution studies of Pirocarbotrat were carried out, we found that the 84.50 +/- 2.60% of the activity remained in the tumor with almost null irradiation of the other organs under study. When therapeutic action was evaluated, we observed that the percentage of tumor regression was 78.3% for the tumors injected with Pirocarbotrat. The other dispersions under study showed different behaviors with high activity percentages distributed throughout the organism. These studies demonstrate that Pirocarbotrat has the best radiopharmacological properties to ensure irradiation of the tumor with the least concomitant irradiation of surroundings or other organs or tissues.
Asunto(s)
Adenocarcinoma/metabolismo , Carbón Orgánico/química , Neoplasias Mamarias Experimentales/metabolismo , Fosfatos/farmacocinética , Radioisótopos de Fósforo/farmacocinética , Adenocarcinoma/inducido químicamente , Adenocarcinoma/radioterapia , Animales , Carbón Orgánico/farmacocinética , Femenino , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/radioterapia , Tasa de Depuración Metabólica , Metilnitrosourea , Fosfatos/uso terapéutico , Radioisótopos de Fósforo/uso terapéutico , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
A methodology for the determination of iron in foods fortified with this element or in nutritional products is important and has to be sensitive and rapid. In developing countries, an inexpensive and reliable methodology is also required. For this purpose, the Gordon's Ferrozine technique was slightly modified and assayed with yogurt, dry powdered milk, and cereal mixtures, all of them fortified with iron, using an internal standard as the reference methodology. The obtained results demonstrate a close correlation between the standard curve interpolation method and the internal standard reference method (correlation coefficient r2 = 0.9950) in a wide range of concentrations. The slope (0.9998+/-0.0040) demonstrates that both procedures measure equal amounts of iron. The conclusion is that the proposed technique is a reliable, practical, and inexpensive methodology for iron determination in different foods fortified with iron.
Asunto(s)
Ferrozina/química , Análisis de los Alimentos/métodos , Hierro/análisis , Estándares de ReferenciaRESUMEN
To evaluate the effectiveness of a single intratumoral dose of Pirocarbotrat, a gelatin-protected charcoal suspension labeled with chromic [32P]pyrophosphate, studies of bioelimination, biodistribution and therapeutic action were carried out in rats, and the results obtained were compared with those of other 32P dispersions. We found that 78.3% of the treated tumors reduced size after 32 days of treatment. At that time, the total eliminated activity was 12.70 +/- 3.90% distributed in urine (8.30 +/- 1.80%) and feces (4.40 +/- 3.50%). Biodistribution studies demonstrate that 84.50 +/- 2.60% of the injected activity remained in the tumor, with no significant concentration in the rest of the organism. We conclude that Pirocarbotrat can be used as a safe agent for brachytherapy of solid tumors with beta particles.
Asunto(s)
Partículas beta/uso terapéutico , Braquiterapia , Difosfatos/uso terapéutico , Neoplasias Mamarias Experimentales/radioterapia , Radioisótopos de Fósforo/uso terapéutico , Animales , Carbón Orgánico , Femenino , Gelatina , Neoplasias Mamarias Experimentales/inducido químicamente , Metilnitrosourea , Ratas , Ratas Sprague-DawleyRESUMEN
The behavior of SFE-171 used for food fortification was studied. The biological and nutritional properties of this new iron source are discussed in this work.
Asunto(s)
Productos Lácteos/normas , Compuestos Ferrosos/análisis , Manipulación de Alimentos/métodos , Alimentos Fortificados/normas , Hierro de la Dieta/administración & dosificación , Leche/normas , Adulto , Animales , Disponibilidad Biológica , Preescolar , Productos Lácteos/análisis , Relación Dosis-Respuesta a Droga , Femenino , Compuestos Ferrosos/metabolismo , Compuestos Ferrosos/farmacocinética , Alimentos Fortificados/análisis , Hematócrito , Humanos , Lactante , Hierro/análisis , Hierro/sangre , Hierro/farmacocinética , Hierro de la Dieta/metabolismo , Hierro de la Dieta/farmacocinética , Masculino , Intercambio Materno-Fetal , Ratones , Leche/química , Leche/metabolismo , Estado Nutricional , Embarazo , Factores de Tiempo , Agua/análisisRESUMEN
In order to evaluate the effectiveness of an intratumorally single dose of chromic [32P] phosphate for the treatment of solid tumors, studies of bioelimination, biodistribution, and therapeutic action were carried out. Only for comparative purposes were similar studies undertaken using a solution of sodium [32P] orthophosphate-gelatin. Results show that when sodium [32P] orthophosphate-gelatin was intratumorally injected, the percentage of total elimination, after 32 days of treatment, was equal to 85.90 +/- 8.70%, with a higher percentage in urine (64.50 +/- 13.70%) than in feces (21.40 +/- 4.50%). In biodistribution studies, the greater percentage was found in bone (15.54 +/- 2.21%), whereas only 2.51 +/- 0.39% remained in the tumor. When chromic [32P] phosphate was intratumorally injected, we found that the total elimination was equal to 51.70 +/- 6.90%, with a higher amount in feces (32.70 +/- 4.80%) than in urine (19.00 +/- 3.60%). Biodistribution studies demonstrated that 28.93 +/- 1.30% was still in the tumor and 19.01 +/- 1.30% of the injected activity was found in the liver. On the other hand, when therapeutic action was evaluated, no tumoral regression was observed. These results demonstrate that the colloid of chromic [32P] phosphate cannot be used in the treatment of solid tumors as it mobilizes from the injection point, delivering a high dose to the entire organism.
Asunto(s)
Adenocarcinoma/radioterapia , Neoplasias Mamarias Experimentales/radioterapia , Fosfatos/farmacocinética , Fosfatos/uso terapéutico , Radioisótopos de Fósforo/farmacocinética , Radioisótopos de Fósforo/uso terapéutico , Adenocarcinoma/metabolismo , Animales , Compuestos de Cromo , Coloides , Femenino , Neoplasias Mamarias Experimentales/metabolismo , Tasa de Depuración Metabólica , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
Iron deficiency is the most important nutritional problem all over the world. Fluid milk is an attractive vehicle for iron fortification, since it is a food with a high nutritional value, accessible to the whole population and easy to be given to children. Fortification of this food with iron has the disadvantage of the interaction of the iron with the constitutive elements of milk, diminishing its bioavailability and changing its sensorial properties, making it unacceptable. Nowadays, this problem can be overcome by the implementation of a new technological procedure, which consists in the microencapsulation of the ferrous sulfate with lecithin, thus avoiding the interaction of iron with the food. The absorption obtained in mice for milk-ferrous sulfate was 7.9 +/- 3.2%, while for microencapsulated ferrous sulfate-milk the result was 11.6 +/- 4.5%. Comparing these data with those obtained with the ferrous ascorbate in water 13.1 +/- 4.9% and ferrous sulfate in water 13.2 +/- 4.3%, both of them considered as reference standards, no statistically significant difference between them and the microencapsulated ferrous sulfate in milk can be observed. However, this difference becomes significant (p < 0.01) when these products are compared to the non-encapsulated ferrous sulfate in milk. On the other hand, we demonstrated that this product is stable to heat-processing (100 degrees C, 30 min) and storage at a room temperature up to 6 months that lacteous products are usually submitted to.
Asunto(s)
Compuestos Ferrosos/química , Compuestos Ferrosos/farmacocinética , Leche , Absorción , Animales , Ácido Ascórbico/farmacocinética , Disponibilidad Biológica , Composición de Medicamentos , Estabilidad de Medicamentos , Femenino , Calor , Ratones , Fosfatidilcolinas , Factores de TiempoRESUMEN
With the purpose of studying the effectivity of an intratumoral single dose of chromic [32P] phosphate with great particles for the treatment of solid tumors, studies of bioelimination, biodistribution and therapeutic action were carried out. Only for comparative purposes, similar studies were undertaken using a solution of sodium -32P- orthophosphate-gelatine. The results show that when sodium [32P] orthophosphate-gelatine is used, the percentage of total elimination is (85.90 +/- 8.70)% with a higher percentage in urine (64.50 +/- 13.70)% than in faeces (21.40 +/- 4.50)%. In biodistribution studies, the greater percentage is found in bone (15.54 +/- 2.21)% while only a (2.51 +/- 0.39)% remains in the tumor. When great particles chromic [32P]phosphate was intratumorally injected, we determined that the total elimination is equal (36.28 +/- 6.27)%, finding a higher amount in faeces (29.44 +/- 5.26)% than in urine (6.84 +/- 2.21)%. Biodistribution studies demonstrated that (49.82 +/- 5.41)% remains in the tumor and (9.63 +/- 4.89)% of the injected activity is found in the liver. On the other hand, when therapeutic action was evaluated, we observed that the percentage of tumor regression (P.T.R.) is 52.0% for the tumors injected with chromic [32P]phosphate and 0.0% for those injected with sodium [32P]orthophosphate-gelatine. These results show that the great particles colloid of chromic [32P]phosphate is not safe enough for the treatment of solid tumors, since it is mobilized from the injection point, delivering a high dose to the whole organism.
Asunto(s)
Adenocarcinoma/radioterapia , Compuestos de Cromo/uso terapéutico , Neoplasias Mamarias Experimentales/radioterapia , Fosfatos/uso terapéutico , Animales , Compuestos de Cromo/administración & dosificación , Compuestos de Cromo/farmacocinética , Heces/química , Femenino , Inyecciones , Fosfatos/administración & dosificación , Fosfatos/farmacocinética , Ratas , Ratas Sprague-Dawley , Inducción de Remisión , Resultado del Tratamiento , Orina/químicaRESUMEN
The difficulty of a reliable diagnosis of pancreatic diseases by scintiscanning, is mainly derived from the lack of adequate radiopharmaceuticals. With this purpose 125I-L-3 Iodo-a-Methyl Tyrosine (125I-IMT) has been studied, which has also been used for the diagnosis of different kind of brain tumors. The purpose of this work is the development of a quick and easy method for the synthesis and purification of the 125I-IMT in order to be used in a Nuclear Medicine Service. The L-alpha-Methyl Tyrosine was labeled with 125I using I-/I03 and afterwards purified by an anionic exchange resin. The labeling yield obtained was (96.0 +/- 0.5)% when the incubation time was 15 minutes. No significant statistical differences were observed when the incubation time was extended to 1 hour. Biodistribution studies in mice show that the percentage of activity concentration in pancreas is (34.24 +/- 14.03)% at 15 minutes post injection, remaining constant for 30 minutes. The pancreas/liver ratio 15 minutes after the injection of the labeled product was (12.22 +/- 3.59) and it remained constant for 45 minutes more. These results show that 125I-IMT can be used as a diagnostic agent for pancreatic diseases. Since 123I was not available at the moment, this new methodology was developed with 125I.
Asunto(s)
Diagnóstico por Imagen , Metiltirosinas , Neoplasias Pancreáticas/diagnóstico por imagen , Análisis de Varianza , Animales , Electroforesis en Papel , Radioisótopos de Yodo , Ratones , CintigrafíaRESUMEN
Iron deficiency is one of the most important nutritional problems in the world. The best method to overcome this problem is the fortification of foods with highly bioavailable iron. Fluid milk is a massive consumption food with an easy access and which is generally the only food intake during the first months of life. Therefore the fortification of fluid milk with highly bioavailable iron and no detectable alterations of its sensorial characteristics was studied in the present work. This procedure was made possible using a new type of ferrous sulfate, stabilized and microencapsulated with soy lecitin (SFE-171). The iron concentration of the fortified milk is 12 mg per liter. In order to study the iron absorption from milk fortified with this product, SFE-171 was labeled with 59Fe and given to 29 volunteers with a normal iron status, each of which received an iron quantity of 3 mg in 250 ml of fluid milk. The average iron absorption was (10.2 +/- 4.7) %. This result shows that the iron given in this physicochemical form has the advantage of a high bioavailability and it is possible that this product will be the first attempt for an adequate solution of iron deficiency.
Asunto(s)
Compuestos Ferrosos/farmacocinética , Hierro de la Dieta/sangre , Leche Humana/química , Leche/química , Fenómenos Fisiológicos de la Nutrición , Adulto , Anemia Ferropénica/prevención & control , Animales , Disponibilidad Biológica , Humanos , MasculinoRESUMEN
The difficulty of a reliable diagnosis of pancreatic diseases by scintiscanning, is mainly derived from the lack of adequate radiopharmaceuticals. With this purpose (125) I-L(-3) Iodo-a-Methyl Tyrosine ((125) I-IMT) has been studied, which has also been used for the diagnosis of different kind of brain tumors. The purpose of this work is the development of a quick and easy method for the synthesis and purification of the (125) I-IMT in order to be used in a Nuclear Medicine Service. The L-(-Methly Tyrosine was labeled with (125) I using I-/I03 and afterwards purified by an aniomic exchange resin. The labeling yield obtained was (96.0+0.5) per cent when the incubation time was 15 minutes. No significant statistical differences were observed when the incubation time was extended to 1 hour. Biodistribution studies in mice show that the percentage of activity concentration in pancreas is (34.24+14.03) per cent at 15 minutes post injection, remaining constant for 30 minutes. The pancreas/liver ratio 15 minutes after the injection of the labeled product was (12.22+3.59) and it remained constant for 45 minutes more. These results show that (125) I-IMT cab be used as a diagnostic agent for pancreatic diseases. Since (123) I was not avilable at the moment, this new methodology was developed with (125) I. (AU)
Asunto(s)
Ratones , Animales , Neoplasias Pancreáticas/diagnóstico por imagen , Metiltirosinas/diagnóstico , Diagnóstico por Imagen , Radioisótopos de Yodo/diagnóstico , Electroforesis en Papel , Análisis de VarianzaRESUMEN
With the purpose studying the effectivity of an intratumoral single dose of chromic [(32)P] phosphate with great particles for the treatment of solid tumors, studies of biolimination, biodistribution and therapeutic action were carried out. Only for comparative purpose, similar studies were undertaken using a solution of sodium [(32)P] orthophosphategelatine. The results show that when sodium [(32)P] orthophosphategelatine is used, the percentage of total elimination is (85.90+8,70) per cent with a higler percentage in urine (64.50+13.70) per cent than in faeces (21.40+4.50) per cent. In biodistribution studies, the greater percentage is found in bone (15.54+2.21) per cent while only a (2.51+0.39) per cent remains in the tumor. When great particles chromic [(32)P] phosphate was intratumorally injected, we determined that the total elimination is equal (36.28+6.27) per cent, finding a higler amount in faeces (29.44+5.26) per cent than in urine (6.84+2.21) per cent. Biodistribution studies demonstrated that (49.82+5.41) per cent remains in the tumor and (9.63+4.89) per cent of the injected activity is found in the liver. On the other hand, when therapeutic action was evoluted, we observed that the percentage of tumor regression (P.T.R) is 52.0 per cent for the tumors injected with chromic [(32)P] phosphate and 0.0 per cent for those injected with sodium [(32)P] orthophosphate-gelatine. These results show that the great particles colloid of chromic [(32)P] phosphate is not safe enough for the tratment of solid tumors, since it is mobilezed from the injection point, delivering a high dose to the whole organism. (AU)
Asunto(s)
Animales , Ratas , Femenino , Estudio Comparativo , Adenocarcinoma/radioterapia , Neoplasias Mamarias Experimentales/radioterapia , Compuestos de Cromo/uso terapéutico , Fosfatos/uso terapéutico , Sodio/uso terapéutico , Radioisótopos de Fósforo/uso terapéutico , Compuestos de Cromo/administración & dosificación , Compuestos de Cromo/farmacocinética , Fosfatos/administración & dosificación , Fosfatos/farmacocinética , Sodio/administración & dosificación , Sodio/farmacocinética , Radioisótopos de Fósforo/administración & dosificación , Radioisótopos de Fósforo/farmacocinética , Coloides , Inyecciones , Heces/química , Orina/química , Inducción de Remisión , Resultado del Tratamiento , Ratas Sprague-DawleyRESUMEN
The difficulty of a reliable diagnosis of pancreatic diseases by scintiscanning, is mainly derived from the lack of adequate radiopharmaceuticals. With this purpose (125) I-L(-3) Iodo-a-Methyl Tyrosine ((125) I-IMT) has been studied, which has also been used for the diagnosis of different kind of brain tumors. The purpose of this work is the development of a quick and easy method for the synthesis and purification of the (125) I-IMT in order to be used in a Nuclear Medicine Service. The L-(-Methly Tyrosine was labeled with (125) I using I-/I03 and afterwards purified by an aniomic exchange resin. The labeling yield obtained was (96.0+0.5) per cent when the incubation time was 15 minutes. No significant statistical differences were observed when the incubation time was extended to 1 hour. Biodistribution studies in mice show that the percentage of activity concentration in pancreas is (34.24+14.03) per cent at 15 minutes post injection, remaining constant for 30 minutes. The pancreas/liver ratio 15 minutes after the injection of the labeled product was (12.22+3.59) and it remained constant for 45 minutes more. These results show that (125) I-IMT cab be used as a diagnostic agent for pancreatic diseases. Since (123) I was not avilable at the moment, this new methodology was developed with (125) I.