O uso do cloridrato de piridoxina para induzir estro em cadelas / The use of pyridoxine chloridrate to induce estrus in female dogs

Os agonistas dopaminérgicos são utilizados para induzir estro em cadelas, pois atuam na síntese e liberação de prolactina. Objetivou-se avaliar o efeito da piridoxina como indutor de estro em cadelas por agir na neurotransmissão dopaminérgica. Foram selecionadas 40 cadelas em anestro, divididas em quatro grupos experimentais, tratadas com 10mg/kg/dia (G1) e 50mg/kg/dia (G2) de cloridrato de piridoxina, 5µg/kg/dia (G3) de cabergolina e grupo controle/placebo (G4) por até 20 dias. Foram realizadas citologias vaginais a cada 24h para acompanhamento do ciclo estral e análises hormonais (FSH, LH e PRL) no dia zero e 120h do início do tratamento. As cadelas do G3 (100%) manifestaram proestro após 12 dias de tratamento aproximadamente, tempo inferior aos demais grupos (P<0,05). Apenas uma cadela do G1 e uma do G2 ficaram gestantes contra oito fêmeas do G3 e nenhuma do G4 (P<0,05). As concentrações plasmáticas de prolactina foram reduzidas nas fêmeas do G2 e G3 (P<0,05). As demais avaliações hormonais não sofreram influência do tratamento (P>0,05). O cloridrato de piridoxina foi ineficiente para induzir estro em cadelas, mas foi capaz de suprimir a prolactina, de forma semelhante à cabergolina, quando utilizado na dose de 50mg/kg/dia.(AU)

Dopaminergic agonists are used to induce estrus in female dogs as they act in the synthesis and release of prolactin. The objective of this study was to evaluate the effect of pyridoxine as an inducer of estrus by acting on dopaminergic neurotransmission. A total of 40 female dogs in anestrous were divided into four experimental groups treated with 10mg/kg/day (G1) and 50mg/kg/day (G2) of pyridoxine hydrochloride, 5µg/kg/day (G3) of cabergoline and control group/placebo (G4) for up to 20 days. Vaginal cytologies were performed every 24h for follow-up of the estrous cycle and hormonal analyzes (FSH, LH and PRL) on day zero and 120 hours after the start of treatment. The female dogs from G3 (100%) showed proestrus after 12 days of treatment, less time than the other groups (P< 0.05). Only one female from G1 and one from G2 were pregnant against eight from G3 and none from G4 (P< 0.05). Plasma concentrations of prolactin were reduced by treatment in females from G2 and G3 (P< 0.05). The other hormonal evaluations were not influenced by the treatment (P> 0.05). Pyridoxine chloridrate was inefficient to induce estrus in female dogs but was able to suppress prolactin when used at a dose of 50mg/kg/day.(AU)

Homocisteína y trastornos neurocognitivos. ¿Una luz al final del túnel? / Homocysteine and neurocognitive disorders. A light at the end of the tunnel?

El deterioro cognitivo es uno de los procesos que acompañan al envejecimiento y puede depender de factores nutricionales, genéticos o ambientales. La identificación de factores de riesgo modificables proporciona un enfoque esencial para la prevención de dicho deterioro y de los trastornos neurocognitivos. Uno de los factores de riesgo involucrados es la elevada concentración de homocisteína plasmática, la cual se ha relacionado con hallazgos histopatológicos en demencia senil y enfermedad de Alzheimer. Los diferentes estudios sobre esta asociación revelan inconsistencia o contradicción en los resultados. El propósito de esta revisión es relacionar la posible interacción de tres factores en la instalación y progresión del deterioro neurocognitivo: a) factores de tipo nutricional (homocisteína, ácido fólico y vitamina B12), b) la utilización de pruebas para el diagnóstico de disfunción o deterioro cognitivo como el Mini Examen del Estado Mental, y c) la presencia de variantes genéticas polimórficas de la enzima metilentetrahidrofolato reductasa. Una consecuencia directa de esta triple relación es que el tratamiento con ácido fólico y vitamina B12 logra disminuir las elevadas concentraciones de homocisteína plasmática, asumiendo que una mejoría en los síntomas clínicos de deterioro cognitivo puede retrasar los cambios relacionados con progresión a estados demenciales. La intervención temprana mediante políticas de promoción y prevención de la salud mental puede ser efectiva si se comienza con la administración de ácido fólico y vitamina B12 en los estadios iniciales de la alteración cognitiva, logrando así reducir sus funestas consecuencias. Las políticas de salud pública centradas en la salud mental de ancianos pueden identificar a las personas con disfunción cognitiva inicial a través de la promoción de la salud y medidas preventivas; en esta etapa puede ser posible la administración de vitaminas B para reducir o minimizar la progresión del deterioro cognitivo, que podría conducir a trastornos neurocognitivos como la demencia y la enfermedad de Alzheimer

Cognitive impairment is one of the processes that accompany aging and may depend on nutritional, genetic or environmental factors. The identification of modifiable risk factors provides a crucial approach for the prevention of cognitive decline and neurocognitive disorders. One of the risk factors is the high concentration of plasma homocysteine and it has been associated to histopathological changes in senile dementia and Alzheimer´s disease. Clinical trials about this association has shown inconsistent and contradictory results. The purpose of this review is to describe the possible interaction of three factors related with cognitive impairment: a) nutritional factors (homocysteine, folic acid and vitamin B12), b) the use of mental tests such as the Mini Mental State Examination for the diagnosis of cognitive dysfunction, and c) the presence of polymorphic genetic variants of the methylenetetrahydrofolate reductase enzyme. A direct consequence of this triple relationship is the treatment with folic acid and vitamin B12, which decrease high concentrations of plasma homocysteine, with a potential for improvement of the clinical symptoms of cognitive decline, and possibly a delay in the progression towards neurocognitive disorder. Public health policies focused on mental health of older adults can identify people with initial cognitive dysfunction through health promotion and preventive measures, where it can be possible to administer B vitamins in order to reduce or minimize the progression of cognitive decline, that could lead to mental disturbances such as neurocognitive disorders

Consumo de bebidas energizantes en estudiantes universitarios / Consumption of energy drinks in university students

Las bebidas energizantes son productos que se consumen para reducir la sensación de cansancio y favorecer un estado activo, contienen principalmente cafeína, glucosa, glucoronolactona, taurina, guaraná vitaminas B1 (tiamina), vitamina B2 (riboflavina), vitamina B3 (niacina), vitamina B6 (piridoxina). El Objetivo de esta investigación fue determinar la frecuencia del consumo de las bebidas energizantes en los estudiantes de la Universidad Mayor Real y Pontificia de San Francisco Xavier de Chuquisaca y describir los posibles efectos adversos. Se trata de un estudio descriptivo, transversal, cuantitativo realizado en 367 estudiantes universitarios de las áreas de Salud, Económicas - Financieras, Sociales Humanidades, Tecnológicas y Agrarias. Para la recolección de datos se aplicó la encuesta. Entre los resultados se obtuvo que, del total de estudiantes encuestados, 69,21% si han consumido las bebidas energizantes, con una frecuencia de consumo de 2 a 3 veces por mes (39%), principalmente durante los parciales (18.80%) y después de realizar algún deporte (16.89%). Entre las marcas más consumidas de estas bebidas son red bull (30,25%) y power (14,99%).

Energy drinks are products that are consumed to reduce the feeling of tiredness and promote an active state, mainly contain caffeine, glucose, glucoronolactone, taurine, guarana B1 vitamins (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B6 (pyridoxine). The objective of this research was to determine the frequency of the consumption of energy drinks in the students of the Universidad Mayor Real and Pontificia de San Francisco Xavier de Chuquisaca and describe the possible adverse effects. This is a descriptive, cross-sectional, quantitative study conducted on 367 university students in the areas of health, economic - financial, social - humanities, technological and agricultural. The survey was applied to data collection. Among the results it was obtained that, of the total number of students surveyed, 69.21% if they have consumed the energy drinks, with a frequency of consumption of 2 to 3 times per month (39%), mainly during the partial ones (18.80%) and after performing some sport (16.89%). Among the most consumed brands of these drinks are red bull (30.25%) and power (14.99%).

Ácido fólico em excesso: efeitos sobre o metabolismo das vitaminas B2 e B6, o catabolismo do triptofano e a resposta imune / Folic acid excess: effects on vitamin B2 and B6 metabolism, tryptophan catabolism and immune response

Introdução: A suplementação com ácido fólico (AF) é recomendada em algumas condições para evitar a deficiência de folato, como para mulheres no período periconcepcional e durante a gestação. Atualmente, existe uma preocupação quanto ao consumo excessivo de AF pela população pelo uso de suplementos com altas doses dessa vitamina. As vitaminas B6 e B2 agem como cofatores no metabolismo de um carbono, e o uso de altas doses de AF pode influenciar o metabolismo de ambas vitaminas e, consequentemente, interferir em metabolismos importantes das quais elas participam, como a via das quinureninas, e no sistema imune. Objetivo: Avaliar os efeitos da intervenção diária com uma alta dose de AF (5 mg) por 90 dias sobre marcadores do estado das vitaminas do complexo B, e as consequências sobre os metabólitos da via das quinureninas e o sistema imune em adultos saudáveis. Material e Métodos: 64 indivíduos saudáveis foram submetidos à intervenção diária com 5 mg de AF por 90 dias. Coletas de sangue foram realizadas antes (baseline) e após 45 e 90 dias de intervenção. As concentrações séricas de folato e vitamina B12 foram avaliadas por métodos microbiológicos. As concentrações séricas das vitaminas B6 (piridoxal 5'-fosfato (PLP), piridoxal (PL) e ácido 4-piridóxico (PA)), B2 (riboflavina e flavina mononucleotídeo (FMN)), B1 (tiamina e tiamina monofosfato (TMP)) e B3 (ácido nicotínico, nicotinamida e N1-metilnicotinamida), bem como de triptofano, quinurenina e metabólitos, foram avaliadas por LC-MS/MS. A proteína C-reativa ultrassensível (PCRus) foi determinada por imunoturbidimetria, e as concentrações séricas de interleucina (IL)-6, IL-8, IL-10, interferon gama (IFN-γ) e fator de necrose tumoral alfa (TNF-α) foram avaliadas por ensaio multiplex. A expressão de RNAm de DHFR (dihidrofolato redutase), MTHFR (metilenotetrahidrofolato redutase), IL8, TNFA e IFNG em leucócitos mononucleares (PBMC) foram avaliadas por PCR em tempo real. O número de células T regulatórias (Treg) (CD3+, CD4+, CD25high, FoxP3+, CD127-) foi avaliado após incubação dos PBMC com PMA e ionomicina ou veículo por 18h, por imunofenotipagem. Resultados: Houve um grande aumento das concentrações de folato sérico após 45 e 90 dias de intervenção com AF. Não houve diferença nas concentrações de vitamina B12 antes e após a intervenção. As concentrações séricas de PLP foram semelhantes antes e após a intervenção, entretanto, um aumento de PL sérico foi observado após 45 e 90 dias, e de PA após 45 dias, quando comparado ao baseline. Riboflavina e FMN foram maiores após 45 e 90 dias em relação ao baseline. A tiamina sérica foi menor após 45 dias, e as concentrações de TMP foram maiores após 90 dias quando comparados aos períodos anteriores. Não houve diferença nas concentrações de vitamina B3 antes e após a intervenção. Dentre os metabólitos da via das quinureninas, apenas o ácido antranílico apresentou aumento após 45 e 90 dias, enquanto o ácido picolínico diminuiu após 90 dias. PCRus, IL-6, IL-8, IL-10, IFN-γ e TNF-α séricos foram semelhantes no baseline e após a intervenção. Um aumento da expressão de RNAm de DHFR e TNFA foi observado após, respectivamente, 90 dias e 45 e 90 dias de intervenção. Após 90 dias de intervenção com AF, foi observada diminuição do número de células Treg após estímulo com PMA e ionomicina. Conclusão: O uso diário de 5 mg de AF foi associado a alterações nas concentrações séricas de marcadores do estado de vitaminas do complexo B e da via das quinureninas, bem como a diminuição do número de células Treg

Introduction: Folic acid (FA) supplementation is recommended in some conditions to avoid folate deficiency, as women during periconceptional period and pregnancy. Currently, there is a concern about the excessive consumption of FA by population by using supplements with high doses of this vitamin. Vitamins B6 and B2 are cofactors of enzymes of one carbon metabolism and, consequently, may disturb key metabolism in which they participate, as kynurenine pathway, and the immune system. Aim: To assess the effects of a daily intervention with high dose of FA (5 mg) for 90 days on biomarkers of complex B vitamins status and its outcomes in kynurenine pathway metabolites and immune system in healthy adults. Material and Methods: 64 healthy individuals were submitted to a daily intervention with 5 mg of FA for 90 days. Blood samples were collected before (baseline) and after 45 and 90 days of intervention. Serum folate and vitamin B12 were assessed by microbiological assays. Serum vitamin B6 (pyridoxal 5'-phosphate (PLP), pyridoxal (PL) and 4-pyridoxic acid (PA)), vitamin B2 (riboflavin and flavin mononucleotide (FMN)), vitamin B1 (thiamin and thiamin monophosphate)) and vitamin B3 (nicotinic acid, nicotinamide and N1-methylnicotinamide), as well as tryptophan, kynurenine and metabolites, were assessed by LC-MS/MS. C-reactive protein (hs-CPR) was assessed by immunoturbidimetry, and serum interleukin (IL)-6, IL-8, IL-10, interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) were assessed by multiplex assay. Mononuclear leukocytes mRNA expression of DHFR (dihydrofolate reductase), MTHFR (methylenetetrahydrofolate reductase), IL8, TNFA and IFNG were assessed by real time PCR. Regulatory T Cell (Treg) number (CD3+, CD4+, CD25high, FoxP3+, CD127-) was determined after mononuclear leukocytes incubation with PMA and ionomycin or vehicle for 18h, by immunophenotyping. Results: A great increase on serum folate was observed after 45 and 90 days of FA intervention. No differences in serum vitamin B12 were observed before and after intervention. Serum PLP was similar before and after intervention, however, an increase in serum PL was observed after 45 and 90 days, and in PA after 45 days, when compared to baseline. Riboflavin and FMN were increased after 45 and 90 days than in baseline. Serum thiamine was decreased after 45 days than in baseline. Serum TMP was increased after 90 days when compared with previous timepoints. No differences in vitamin B3 were observed after and before FA intervention. Among kynurenine pathway metabolites, anthranilic acid was increased after 45 and 90 days, while picolinic acid was decreased after 90 days. hs-CPR, serum IL-6, IL-8, IL-10, IFN-γ and TNF-α were similar at baseline and after intervention. An increase on mRNA expression of DHFR and TNFA was observed after, respectively, 90 days and 45 and 90 days of intervention. After 90 days of FA intervention, it was observed a decrease on Treg cell number after PMA and ionomycin stimulation. Conclusion: Daily use of 5 mg of FA was associated with changes in serum markers of B-complex vitamins status and kynurenine pathway, as well as decreased number of Treg cells

Pseudotumor cerebral asociado a hipovitaminosis A, B6 y D: A propósito de dos casos / Pseudotumor cerebri associated with hypovitaminosis A, B6 and D: About two cases

La hipertensión endocraneana idiopàtica se asocia infrecuentemente con la hipovitaminosis A y D. Se presenta el caso de una paciente femenina de 8 años con visión borrosa de 24 horas y papiledema bilateral. Resonancia magnética nuclear normal. Presión de apertura de líquido cefalorraquídeo: 260 mm^O. Presentó déficit de vitamina A y D, e inició un tratamiento sustitutivo. El segundo caso corresponde a un paciente masculino de 12 años con fiebre y odinofagia de 3 días. Con antecedente de glomerulonefritis y sobrepeso. Presentaba edema bipalpebral y papiledema. Tomografia axial computada de la órbita: aumento de líquido en la vaina de ambos nervios ópticos. Resonancia magnética nuclear: aracnoidocele intraselar. Presión de apertura de líquido cefalorraquídeo: 400 mm^O. Presentó déficit de vitamina D y B6, e inició el tratamiento sustitutivo. La elevación de la presión intracraneal desencadena mecanismos de compensación que, al fallar, pueden comprometer la vida o provocar graves discapacidades neurológicas. Reconocer la causa para un enfoque terapéutico preciso es clave para disminuir la morbimortalidad asociada a esta patología.

Idiopathic endocranial hypertension is infrequently associated with hypovitaminosis A and D. The case of an 8-year-old female with 24-hour blurred vision and bilateral papilledema is presented. Nuclear magnetic resonance was normal. Opening pressure of cerebrospinal fluid: 260 mm^O. She presented vitamin A and D deficiency and started replacement therapy. The second case corresponds to a 12-year-old male with fever and odynophagia of 3 days. History of glomerulonephritis and overweight. He had bipalpebral edema and papilledema. Computed tomography scan of the orbit: increase of fluid in the sheath of both optic nerves. Nuclear magnetic resonance: intrasellar arachnoidocele. Opening pressure of cerebrospinal fluid: 400 mmH2O. He presented vitamin D and B6 deficiency and started replacement treatment. The elevation of intracranial pressure triggers compensation mechanisms that, when they fail, can compromise life or cause serious neurological disabilities. Recognizing the cause for an accurate therapeutic approach is key to reduce the morbidity and mortality associated with this pathology.

Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

Introduction: The purpose of this study was to investigate the effects of isolated vitamin B6 (VB6 ) supplementation on experimental hyperhomocysteinemia (Hhe) induced by homocysteine thiolactone (HcyT). Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB6, HcyT, and HB6 ). On the 30th day of treatment, two groups were supplemented with VB6 in the drinking water (groups: CB6 and HB6 ). After 60 days of treatment, homocysteine (Hcy), cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2)-like 2 (NRF2) and glutathione S-transferase (GST) immunocontent, and superoxide dismutase (SOD), catalase (CAT), and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62%) in relation to the CB6 group. Additionally, GST immunocontent was enhanced (51%) in the HB6 group compared to the HcyT group. Also, SOD activity was lower (17%) in the HB6 group compared to the CB6 group, and CAT activity was higher in the HcyT group (53%) compared to the CB6 group. Ejection fraction (EF) was improved in the HB6 group compared to the HcyT group. E/A ratio was enhanced in the HB6 group compared to the CB6 group. Correlations were found between CAT activity with myocardial performance index (MPI) (r = 0.71; P = 0.06) and E/A ratio (r = 0.6; P = 0.01), and between EF and GST activity (r = 0.62; P = 0.02). Conclusions: These findings indicate that isolated VB6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters (AU)

Efecto de un incremento en la diuresis sobre la absorción y retención de algunos nutrientes en ratas / Effect of an increase in diuresis on absorption and retention of some nutrients in rats

Estudios previos en ratas han demostrado que la administración del diurético furosemida aumenta la pérdida urinaria de electrolitos y nutrientes, causando un efecto negativo sobre las reservas de los mismos. Una alternativa para proteger esas reservas es incrementar la absorción intestinal. Así, se evaluó la absorción, pérdidas urinarias y reservas corporales de nitrógeno, calcio, magnesio, sodio, potasio y cinc, en cuatro grupos de ratas: control, y tres grupos experimentales que consumieron furosemida en concentraciones de 0,5; 1,0 y 1,5 mg/g de dieta, durante 23 días. El diurético causó poliuria dosis dependiente, disminución en el consumo de alimento, la eficiencia y el crecimiento. También, provocó un aumento en las pérdidas urinarias del nitrógeno y minerales. La absorción de nitrógeno, calcio y cinc no se modificó, mientras que la del magnesio, sodio y potasio aumentó ligeramente. Se determinó que la absorción no compensó las pérdidas urinarias. Así, la furosemida afectó negativamente la retención de nutrientes y electrolitos, provocando una reducción en las reservas corporales de los mismos. Este diurético tiene un efecto negativo sobre el estado nutricional en ratas, causado por la reducción en el consumo de alimento, así como en la utilización de los nutrientes consumidos. La reducción en la utilización de los nutrientes asociada con este diurético, puede ser explicada en parte, por una pobre retención de nutrientes por el riñón, que no puede ser compensada por un incremento en la absorción intestinal.

Previous studies have shown that, in rats, the administration of the diuretic furosemide increases diuresis as well as urinary loss of electrolytes and essential nutrients. This loss has a negative effect on electrolytes and nutrient reserves. Since one alternative to help protect these reserves is to increase intestinal absorption, the purpose of this study was to evaluate the absorption, urinary loss and tissue reserves of nitrogen, calcium, magnesium, sodium, potassium and zinc in rats offered 0, 0.5, 1.0 and 1.5 mg furosemide per g diet, daily during 23 days. The diuretic caused a dose dependent polyuria, a reduction in food intake, growth and feed efficiency. In addition, those rats had increased urinary loss of nitrogen and minerals. Nitrogen, calcium and zinc absorption were not affected, but magnesium, sodium and potassium increased slightly. Intestinal absorption could not compensate for urinary loss. In general, this study showed that in rats, this diuretic had a negative effect on nutritional status caused by a reduction in food intake and also in the utilization of the nutrients consumed. The reduction in nutrient utilization associated with this diuretic may be partly explained by a poor nutrient retention by the kidney which was not compensated by an increase in intestinal absorption.