Folate and vitamin B12 related to homocysteine and DNA damage in female university students / Folato e vitamina B12 relacionados com homocisteína e danos no DNA em estudantes universitárias / Folato y vitamina B12 relacionados con homocisteína y daño en el ADN en estudiantes universitarias

Background and Objectives: It is not clear whether the increase in nutrition students' knowledge is associated with healthier eating behavior and fewer micronutrient deficiencies that can cause DNA damage. Deficiency in some vitamins can be a risk factor for increased homocysteine (Hcy) levels, a marker of cardiovascular risk. Therefore, this study aimed to verify whether dietary and serum folate and vitamin B12 are associated with Hcy levels and DNA damage in female university students. Methods: A cross-sectional study was conducted with female university students from southern Brazil. Folate, vitamin B12, and Hcy levels were determined in their diet or serum. DNA damage levels were assessed by the alkaline comet assay (index and frequency) and the buccal micronucleus assay (micronuclei frequency and binucleated cells frequency). Results: Correlation analyses did not show an association between Hcy levels and dietary or serum folate and vitamin B12 consumption. Dietary folate and vitamin B12 were associated with the index and frequency of damages; however, only serum folate was negatively associated with the index and frequency of damages. Additionally, the frequency of binucleated cells was negatively associated with dietary vitamin B12 and positively associated with serum levels. Serum folate was negatively associated with the frequency of micronuclei. Hcy levels were associated with the index and frequency of damages. Conclusion: These findings strengthen the role of healthier dietary patterns with adequate micronutrients as a preventive strategy to reduce the risk of cardiovascular diseases. This approach should play a pivotal role in shaping health policies and advocating for appropriate food choices.(AU)

Justificativa e Objetivos: Não está claro se o aumento do conhecimento dos estudantes de nutrição está associado a um comportamento alimentar mais saudável, com menores deficiências de micronutrientes que podem induzir danos no DNA. A deficiência de algumas vitaminas pode ser um fator de risco para o aumento dos níveis de homocisteína (Hcy), um marcador de risco cardiovascular. Portanto, este estudo verificou se folato e vitamina B12 dietético e sérico estão associados aos níveis de Hcy e danos no DNA em estudantes universitárias. Métodos: Estudo transversal com universitárias do sul do Brasil. Determinou-se folato, vitamina B12 e Hcy dietético e séricos. Os níveis de danos no DNA foram avaliados pelo ensaio do cometa alcalino (índice e frequência) e pelo ensaio de micronúcleos bucais (frequência de micronúcleos e células binucleadas). Resultados: Análises de correlação não mostraram associação entre os níveis de Hcy com o consumo de folato e vitamina B12 dietético ou sérico. Folato e vitamina B12 dietéticos associou-se ao índice e frequência de danos, entretanto, somente folato sérico associou-se negativamente ao índice e frequência de danos. Ainda, a frequência de células binucleadas estava negativamente associada à vitamina B12 da dieta e positivamente associada aos níveis séricos. Folato sérico associou-se negativamente à frequência de micronúcleos. Os níveis de Hcy associou-se ao índice e frequência de danos. Conclusão: Esses achados fortalecem o papel de padrões alimentares mais saudáveis com micronutrientes adequados como estratégia preventiva visando a redução do risco de doenças cardiovasculares. Esta abordagem deve desempenhar um papel fundamental na formulação de políticas de saúde e na defesa de escolhas alimentares apropriadas.(AU)

Justificación y Objetivos: No está claro si el aumento del conocimiento de estudiantes de nutrición está asociado con un comportamiento alimentario más saludable, con menores deficiencias de micronutrientes que puedan inducir daños en ADN. La deficiencia de algunas vitaminas puede ser un factor de riesgo para el aumento de los niveles de homocisteína (Hcy), marcador de riesgo cardiovascular. Consiguiente, este estudio verificó si folato y vitamina B12 dietéticos y séricos están asociados con niveles de Hcy y daños en el ADN en estudiantes universitarias. Métodos: Estudio transversal con universitarias del sur de Brasil. Se determinaron folato, vitamina B12 y Hcy dietéticos y séricos. Los niveles de daño en el ADN se evaluaron por ensayo del cometa alcalino (índice y frecuencia) y el ensayo de micronúcleos bucales (frecuencia de micronúcleos y células binucleadas). Resultados: Los análisis de correlación no mostraron asociación entre los niveles de Hcy con folato y vitamina B12 dietéticos y séricos. Folato y vitamina B12 dietéticos se asociaron con índice y frecuencia de daños, pero, solo folato sérico se asoció negativamente con índice y frecuencia de daños. Además, la frecuencia de células binucleadas estaba negativamente asociada con la vitamina B12 de la dieta y positivamente asociada con los niveles séricos. Folato sérico se asoció negativamente con la frecuencia de micronúcleos. Los niveles de Hcy se asociaron con índice y frecuencia de daños. Conclusión: Estos hallazgos refuerzan el papel de patrones alimentarios más saludables con micronutrientes adecuados como estrategia preventiva para reducir el riesgo de enfermedades cardiovasculares. Este enfoque debería desempeñar un papel fundamental en la elaboración de políticas de salud y en la promoción de elecciones alimenticias apropiadas.(AU)

Correlación entre Vitamina B12 y presión arterial en adultos / Correlation between Vitamin B12 and blood pressure in adults

Introducción. La vitamina B12 incidiría sobre la presión arterial mediante mecanismos hormonales y metabólicos. Objetivo. Analizar la relación entre las concentraciones de vitamina B12 y la presión arterial en adultos. Materiales y Métodos. Estudio observacional, analítico, retrospectivo y transversal, proveniente de una base de datos abierta conformada por 4154 personas de una comunidad mexicana atendida en un establecimiento de salud. Las variables fueron: sexo, vitamina B12 y presión arterial sistólica. Se utilizó las pruebas Ji-cuadrado y prueba t de student. Resultados.los promedios de vitamina B12 fueron menores en presencia de presión arterial igual o mayor a 130 mmHg (hombres:217,12 pg/ml; mujeres204,51 pg/ml) respecto a cuándo se comparó con niveles de presión arterial sistólica entre 90 a 129 mmHg (hombres; 266,98 pg/ml; mujeres: 205,18 og/ml). La correlación entre vitamina B12 y presión arterial fue baja y negativa en hombres (Rho=-0,022; p=0,018), mujeres (Rho=-0,182; p<0,001) y en ambos grupos en conjunto (Rho=-0,171; p<0,001).Conclusión. Los adultos hipertensos tienen menores promedios de vitamina B12 que los normotensos. Asimismo, la vitamina B12 se correlaciona de forma débil y negativa con la presión arterial. Los niveles normales de vitamina B12 con tendencia hacia los limites bajos podrían ser uno de los muchos factores que inciden en la fisiopatología temprana de la hipertensión arterial. Palabras clave: vitamina B 12; presión arterial; estudio observacional; modelos lineales; correlación de datos

Introduction. Vitamin B12 would affect blood pressure through hormonal and metabolic mechanisms.Objective. To analyze the relationship between vitamin B12 concentrations and blood pressure in adults.Materials and Methods. Observational, analytical, retrospective and cross-sectional study, from an open database made up of 4,154 people from a Mexican community served in a health facility. The variables were: sex, vitamin B12 and systolic blood pressure. The Chi-square test and student's t test were used.Results. the averages of vitamin B12 were lower in the presence of blood pressure equal to or greater than 130 mmHg (men: 217.12 pg/ml; women 204.51 pg/ml) compared to when it was compared with systolic blood pressure levels between 90 at 129 mmHg (men; 266.98 pg/ml; women: 205.18 og/ml). The correlation between vitamin B12 and blood pressure was low and negative in men (Rho=-0.022; p=0.018), women (Rho=-0.182; p<0.001) and in both groups together (Rho=-0.171; p< 0.001). Conclusion. Hypertensive adults have lower averages of vitamin B12 than normotensive adults. Likewise, vitamin B12 is weakly and negatively correlated with blood pressure. Normal levels of vitamin B12 with a tendency towards low limits could be one of the many factors that influence the early pathophysiology of arterial hypertension. Key words:vitamin B12; arterial pressure; observational study; linear models; correlation of data

Sensory peripheral neuropathy aggravated by vitamin B12 in elder patient. A case report

Background@#Vitamin B12 is one of the common drugs used by physicians to treat peripheral neuropathy (PN), although many patients have a good response, however, overdose and toxicity aggravate the condition and worsen the patient’s symptoms. The purpose of this paper is to highlight association between Vitamin B12 toxicity and deterioration of PN symptoms.@*Case Summary@#An elder Sudanese man with acute onset of sensory PN, the patient’s symptoms started by tingling sensations and paresthesia affecting both hands and feet. After patient received cobalamin (vitamin B 12) prescribed by his doctor, the patient symptoms were markedly aggravated and his condition worsened to extend that impaired the normal patient ordinary work. No symptoms related to motor system. Other possible etiologies were studied and excluded. Investigations of his condition revealed blood level of B12 was 1900 pg/mL, the patient condition improved dramatically with discontinuation of the drug.@*Conclusion@#Cobalamin toxicity aggravate sensory PN symptoms. Clinicians are advised to adjust the dose and check Cobalamin level before and during treatment to avoid its toxicity.

Vitaminas B neurotrópicas y neuropatía periférica: estado del arte y acuerdo de expertos / Neurotropic B vitamins and peripheral neuropathy: State of the art and agreement of experts

Propósito: La neuropatía periférica tiene un espectro clínico inespecífico y multifactorial, con frecuente subdiagnóstico y terapéutica de eficacia variable. Existe una heterogénea prescripción de vitaminas B, las cuales pueden desempeñar un rol importante en el manejo de diferentes neuropatías; sin embargo, en Colombia no existen guías clínicas al respecto. El propósito de este trabajo es orientar en el reconocimiento temprano de las neuropatías periféricas y generar recomendaciones sobre el uso adecuado de vitaminas B neurotrópicas. Descripción de la metodología: Acuerdo de expertos sobre la neuropatía periférica y el rol terapéutico de las vitaminas B con énfasis en la epidemiología en Colombia, diagnóstico y tratamiento. Contenidos: En Colombia, la prevalencia de neuropatía periférica se estima cercana al 10 %, sin embargo, no hay datos recientes. Dentro de las etiologías más frecuentes se encuentran la neuropatía diabética, infecciosa, inflamatoria, carenciales, toxica y farmacológica. Se recomiendan las siguientes herramientas de tamizaje en población de riesgo: DN4, MNSI, test de monofilamento, test de vibración y valoración de reflejos. Las vitaminas B1, B6 y B12 son seguras, accesibles y pueden ser eficaces en neuropatía periférica, incluso cuando el déficit no ha sido demostrado, pero con requerimientos particulares en su administración conjunta. Conclusiones: Las neuropatías periféricas son un reto diagnóstico y terapéutico que requiere la identificación oportuna para el tratamiento de la etiología subyacente y el control de síntomas. El uso de vitaminas B neurotrópicas es efectivo y seguro en neuropatía periférica carencial, y también parece ser eficaz en el manejo de neuropatías periféricas de diferentes etiologías.

Purpose: Peripheral neuropathy has a nonspecific and multifactorial clinical spectrum, with frequent underdiagnosis and therapeutics of variable efficacy. There is a high but heterogeneous prescription of B vitamins, which can play an important role in the management of different neuropathies; however, in Colombia there are no clinical guidelines in this regard. The purpose of this article is to guide the early recognition of peripheral neuropathy and generate recommendations on the proper use of neurotropic B vitamins. Description of the methodology: Expert agreement on peripheral neuropathy and the therapeutic role of B vitamins with emphasis on epidemiology in Colombia, diagnosis and treatment. Contents: In Colombia, there are no recent data to estimate the prevalence of peripheral neuropathy; the main etiologies are: diabetes mellitus, nutritional deficiencies, herpes zoster and neuropathies due to chemotherapy. Given risk factors in the anamnesis, the use of DN4, MNSI, monofilament test, vibration test and assessment of reflexes is recommended. Vitamins B1, B6, and B12 are safe and can be effective in peripheral neuropathy, even when the deficit has not been demonstrated, but with special requirements in their joint administration. Conclusions: peripheral neuropathies are a diagnostic and therapeutic challenge, and require timely identification, for the treatment of the underlying etiology and symptom control. The use of neurotropic B vitamins is effective and safe in deficient peripheral neuropathy, and also appears to be effective in the management of peripheral neuropathies of different etiologies.

Pseudo-orthostatic tremor as a manifestation of vitamin B12 deficiency: A case report

@#Vitamin B12 deficiency has long been known to present with various neurological manifestations, but only rarely presents as movement disorders, especially in adults. We present the case of a 30-year-old vegan male presenting with tremors on both legs when standing which was relieved by vitamin B12 supplementation. To the best of our knowledge, this is the first documented case of slow orthostatic tremor or pseudo-orthostatic tremor caused by vitamin B12 deficiency.

Association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 years old in 9 longevity areas of China / 中华预防医学杂志

Objective: To investigate the association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 in 9 longevity areas of China. Methods: The elderly over 65 years old with complete information on plasma vitamin B12 and plasma uric acid from Healthy Aging and Biomarkers Cohort Study (2017 to 2018) were recruited in this study. Information on socio-demographic characteristics, life styles, diet intake, and health status were collected by questionnaire and physical examination; and fasting venous blood was collected to detect the levels of plasma vitamin B12, uric acid and other indicators. Multiple linear regression models were used to analyze the association of plasma vitamin B12 level per interquartile range increase with plasma uric acid level. The association trend of plasma vitamin B12 level with plasma uric acid level was described by restrictive cubic splines fitting multiple linear regression model. Multiple logistic regression models were used to analyze the association of plasma vitamin B12 level stratified by quartiles with hyperuricemia. Results: A total of 2 471 participants were finally included in the study, the age was (84.88±19.76) years old, of which 1 291 (52.25%) were female. The M (Q1, Q3) level of plasma vitamin B12 was 294 (203, 440) pg/ml and the plasma uric acid level was (341.01±90.46) μmol/L. A total of 422 participants (17.08%) were defined with hyperuricemia. The results of multiple linear regression model showed that there was a positive association of plasma vitamin B12 level with plasma uric acid level after adjustment for covariates (P<0.05). An IQR increase in plasma vitamin B12 (237 pg/ml) was associated with a 6.36 (95%CI: 2.00-10.72) μmol/L increase in the plasma uric acid level. The restrictive cubic splines curve showed a positive linear association of log-transformed plasma vitamin B12 with uric acid level (P<0.001). Conclusion: There is a positive association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 years old in 9 longevity areas of China.

Trastornos adquiridos y congénitos de la deficiencia de vitamina B12 en niños / Acquired and inherited disorders of vitamin B12 deficiency in children

Vitamin B12 is an essential micronutrient for cell growth and the development of the central nervous system. Its deficiency can manifest clinically as megaloblastic anemia, peripheral neuropathy, myelopathy and neuropsychiatric disorders. Early detection and treatment are essential as it can cause irreversible neurological sequelae. Diagnosis is often challenging as it is based on clinical and biochemical features. Clinically, the symptoms are nonspecific and equivocal. Biochemically, there is no gold standard to detect Cobalamin deficiency. The available biomarkers do not have a defined cut-off value or are not sensitive or specific enough. This article exposes the different causes of vitamin B12 deficiency, analyzes the advantages and disadvantages of biochemical markers and, for the first time, proposes an algorithmic diagnosis using biomarkers and therapeutic tests. The ultimate goal is to alert pediatricians to the difficulties of diagnosing vitamin B12 deficiency and strategies are proposed to differentiate between acquired and congenital cobalamin conditions. Finally, the treatment according to the etiology is described in a practical manner, as well as the expected time for improvement of the biochemical parameters.

La vitamina B12 es un micronutriente fundamental para el crecimiento celular y el desarrollo del sistema nervioso central. Su deficiencia puede manifestarse clínicamente como anemia megaloblástica, neuropatía periférica, mielopatía y trastornos neuropsiquiátricos. La detección y el tratamiento tempranos son esenciales, ya que esta deficiencia puede generar secuelas neurológicas irreversibles. El diagnóstico suele ser un desafío, ya que se basa en pilares clínicos y bioquímicos. Clínicamente, los síntomas son inespecíficos y equívocos. Bioquímicamente no existe un gold standard para diagnosticar la deficiencia de cobalamina. Los biomarcadores existentes no presentan un valor de corte definido o no son lo suficientemente sensibles o específicos. Este trabajo expone las diferentes causas de deficiencia de vitamina B12, analiza las ventajas y desventajas de los marcadores bioquímicos y por primera vez se plantea un algoritmo diagnóstico mediante biomarcadores y pruebas terapéuticas. El objetivo último es alertar a los pediatras acerca las dificultades que representa el diagnóstico de deficiencia de vitamina B12 y se proponen estrategias para diferenciar cuadros adquiridos versus congénitos de la deficiencia de cobalamina. Por último, se describe de manera práctica el tratamiento según la etiología así como el tiempo esperado para la mejoría de los parámetros bioquímicos.

The Role of Thyroid Hormones, Vitamins, and Microelements in Female Infertility / O papel dos hormônios da tiroide, das vitaminas e dos microelementos na fertilidade feminina

Abstract Objective It is well known that female infertility is multifactorial. Therefore, we aimed to compare the effects of thyroid dysfunction, vitamin deficiency, and microelement deficiency in fertile and infertile patients. Materials and Methods Between May 1st, 2017, and April 1st, 2019, we conducted a retrospective case-control study with of 380 infertile and 346 pregnant patients (who normally fertile and able to conceive spontaneously). The fertile patients were selected among those who got pregnant spontaneously without treatment, had a term birth, and did not have systemic or obstetric diseases. The levels of thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), anti-thyroid peroxidase (anti-TPO), vitamin D, vitamin B12, folic acid, ferritin, and zinc of both groups were compared. Results There was no difference between patients in the infertile and pregnant groups in terms of low normal and high serum T3 and T4 levels (p = 0.938; p > 0.05) respectively, nor in terms of normal and high anti-TPO levels (p = 0.182; p > 0.05) respectively. There was no significant difference regarding patients with low, insufficient, and sufficient vitamin D levels in the infertile and pregnant groups (p = 0.160; p >0.05) respectively. The levels of folic acid, ferritin, and zinc of the infertile group were significantly lower than those of the pregnant group. Conclusion The serum levels of folic acid, ferritin, and zinc in infertile patients presenting to our outpatient clinic were lower than those o the fertile patients.

Resumo Objetivo Sabe-se que a infertilidade feminina é multifatorial. Portanto, nosso objetivo foi comparar os efeitos da disfunção tireoidiana, deficiência de vitaminas e deficiência de microelementos em pacientes férteis e inférteis. Materiais e Métodos Entre 1° de maio de 2017 e 1° de abril de 2019, realizamos um estudo retrospectivo caso-controle com 380 pacientes inférteis e 346 grávidas (normalmente férteis e capazes de conceber espontaneamente). As pacientes férteis foram selecionadas entre aquelas que engravidaram espontaneamente sem tratamento, tiveram parto a termo e não apresentavam doenças sistêmicas ou obstétricas. Os níveis de hormônio estimulante da tireoide (TSH), triiodotironina (T3), tiroxina (T4), antitireoide peroxidase (anti-TPO), vitamina D, vitamina B12, ácido fólico, ferritina e zinco de ambos os grupos foram comparados. Resultados Não houve diferença entre as pacientes dos grupos inférteis e gestantes em relação aos níveis altos de sérumT3 e T4 normais baixos e altos (p = 0,938; p > 0,05), respectivamente nem aos níveis normais e altos de anti-TPO (p = 0,182; p > 0,05), respectivamente. Não houve diferença significativa em relação aos pacientes com níveis baixos, insuficientes e suficientes de vitamina D nos grupos inférteis e gestantes (p = 0,160; p > 0,05), respectivamente. Os níveis de ácido fólico, ferritina e zinco do grupo infértil foram significativamente menores do que os do grupo grávida. Conclusão Os níveis de sérum de ácido fólico, ferritina e zinco nas pacientes inférteis atendidas em nosso ambulatório foram menores do que nas pacientes férteis.

Polineuropatia diabética assintomática induzida pelo uso crônico de metformina e correlação com vitamina B12 / Asymptomatic diabetic polyneuropathy induced by chronic metformin use and correlation with vitamin B12

Introdução: Diabetes Mellitus é doença metabólica, caracterizada pela deficiência absoluta ou relativa de insulina, que acomete cerca de 382 milhões de pessoas em todo mundo, tendo uma das complicações mais comuns a polineuropatia. A Metformina, medicamento amplamente utilizado como tratamento do Diabetes, foi descrita como responsável, em algumas literaturas, por causar ou agravar deficiência de vitamina B12, que está similarmente relacionada ao desenvolvimento de polineuropatia.Métodos: Nesse sentido, foi conduzido um estudo no município de Soledade ­ RS, com objetivo de verificar se essa relação é condizente com a realidade da localidade. Foram escolhidos 58 pacientes, dos quais 30 responderam questionários adaptados baseados na literatura e na Classificação de Neuropatia de Michigan (MNSS-Brasil), então colhidos 5 ml de sangue venoso da fossa antecubital, preparado soro do qual uma alíquota foi separada para determinação bioquímica da vitamina B12.Resultados: Analisando os resultados, a maioria dos pacientes analisados apresentou sintomas de polineuropatia, e 10% deste, deficiência vitamínica.Conclusão: nenhuma variável explicou a correlação do uso crônico da Metformina, dose e gênero com a deficiência da vitamina B12, o que indica que não há evidências fortes o suficiente que sustentem esse fato, de acordo com as particularidades da localidade analisada.

Introduction: Diabetes Mellitus is a metabolic disease, characterized by absolute or relative insulin deficiency, which affects about 382 million people, with polyneuropathy being one of the most common complications. Metformin, a drug widely used as a treatment for diabetes, has been described as responsible, in some literature, for causing or aggravating vitamin B12 deficiency, which is similarly related to the development of polyneuropathy.Methods: In this sense, a study was conducted in Soledade ­ RS, in order to verify whether this relationship is consistent with the reality of the locality. Fifty-eight patients were selected, of which 30 answered adapted questionnaires based on the literature and on the Michigan Neuropathy Classification (MNSS-Brazil), then 5 ml of venous blood was collected from the antecubital fossa, serum prepared from which an aliquot was separated for biochemical determination of the vitamin B12.Results: Analyzing the results, most of these patients presented symptoms of polyneuropathy and, 10% of them, vitamin deficiency.Conclusion: no variable explained the correlation of chronic use of Metformin, dose and gender with vitamin B12 deficiency, which indicates that there is not enough evidence to support this fact, according to the particularities of the analyzed locality.

Frecuencia de consumo inadecuado de vitamina B12 y sus niveles séricos en personas con diabetes mellitus tipo 2 tratadas con metformina en centros de salud de la Provincia de Buenos Aires / Frequency of inadequate consumption of vitamin B12 and its serum levels in people with diabetes mellitus type 2 under metformin treatment in health centers of the Province of Buenos Aires

Introducción: el uso prolongado de metformina y la carencia de consumo de vitamina B12 (B12) pueden provocar su déficit en pacientes con diabetes mellitus tipo 2 (DM2). Objetivos: analizar la frecuencia de consumo insuficiente de B12 según: características personales, datos antropométricos, de laboratorio y uso de metformina; asociar niveles séricos de cobalamina con dosis y tiempo de metformina; establecer la relación entre la ingesta de B12 y los niveles séricos. Materiales y métodos: diseño transversal. Mediante encuesta de frecuencia de consumo de alimentos fuente de B12 en 200 pacientes tratados con metformina por más de 18 meses. Se analizaron datos clínicos, antropométricos, de laboratorio, tiempo y dosis de metformina, en dos centros de salud de la Provincia de Buenos Aires. Resultados: el porcentual de consumo deficiente fue del 29%. Se registró un 47,5% de desocupación que alcanzó un déficit de ingesta del 32,6%. Se midió B12 sérica en el 65% de la muestra y un 53,8% de los valores fue anormal (0,8% en niveles deficientes o bajos y 23% en niveles normal-bajo), observándose asociación significativa a dosis de metformina ≥1.500 mg. Las deficiencias de consumos de B12 (<2,4 µg/día) fueron casi cuatro veces mayores en el grupo con menor recuento eritrocítico (76,9 % vs 18,5%; p<0,00 ). El volumen corpuscular medio (VCM) y el recuento de plaquetas arrojaron datos estadísticamente significativos. Conclusiones: si bien el 29% de la muestra exhibió consumo vitamínico deficiente, el 90% de los pacientes con déficit sérico registró ingestas adecuadas de B12. Dado que se trató de un diseño transversal, donde no pudo evaluarse causalidad, en pacientes intervenidos farmacológicamente con metformina se sugiere considerar su impacto en situaciones deficitarias.

Introduction: the prolonged use of metformin and the lack of consumption of vitamin B12 can cause its deficit, in T2D. Objectives: to analyze the frequency of insufficient consumption of vitamin B12 according to: personal characteristics, anthropometric and laboratory data, and use of metformin; associate serum cobalamin levels with metformin dose and time; establish a relationship between B12 intake and serum levels. Materials and methods: cross-sectional design. Through a survey of the frequency of consumption of food sources of B12 in 200 patients treated with metformin for more than 18 months. Clinical, anthropometric, laboratory data, time and dose of metformin were analyzed in 2 health centers in the Province of Buenos Aires. Results: the percentage of deficient consumption was 29%. 47.5% of unemployment was registered, which reached an intake deficit of 32.6%. Serum B12 was measured in 65% of the sample where 53.8% of values were abnormal (0.8% in deficient levels) and 23% at levels normal lower cut-off point, with a significant association being observed at doses of metformin ≥1,500 mg. Deficiencies in B12 intake (<2.4 µg/day) were almost 4 times higher in the group with the lowest erythrocyte count (76.9% vs 18.5%; p<0.00 ). The MCV and platelet count yielded statistically significant data. Conclusions: although 29% of the sample exhibited poor vitamin intake, 90% of patients with serum deficiency had adequate intakes of vitamin B12. Given that it is a cross-sectional design, where causality cannot be evaluated, it is suggested: in patients undergoing pharmacological intervention with metformin, consider the impact of this in deficient situations.

La asociación del déficit de vitamina B12 y metformina / The association of vitamin B12 deficiency and metformin

La metformina es el agente antidiabético oral más utilizado para el tratamiento de la diabetes mellitus tipo 2 (DM2) y se ha descrito la asociación de su uso con el déficit de vitamina B12. Se realizó una revisión narrativa de estudios para conocer la evidencia de dicha asociación, y las recomendaciones para su pesquisa, prevención y tratamiento. La prevalencia informada del déficit de vitamina B12 en los pacientes tratados con metformina osciló entre el 5,8% y el 52% en las diferentes series. Los pacientes de mayor edad, aquellos que reciben metformina a altas dosis y por más tiempo, y los que no consumen alimentos de origen animal, son quienes presentan mayor riesgo de padecer este déficit. Se recomienda la determinación de vitamina B12 cada año en pacientes con DM2 tratados con metformina y la eventual reposición en caso de déficit. Si bien existe consenso sobre el tratamiento del déficit, aún falta evidencia que permita realizar la recomendación sobre el tratamiento preventivo.

Metformin is the most widely used oral antidiabetic agent for the treatment of type 2 diabetes (T2D) and the association of the use of this drug with vitamin B12 deficiency has been described. A review of studies was carried out to find out the evidence of this association and the recommendations for its detection, prevention and treatment. The reported prevalence of vitamin B12 deficiency in patients treated with metformin ranged from 5.8% to 52% in the different series. Older patients, those who received metformin at high doses and for a longer time, and those who do not consume food of animal origin, are those who are at greater risk of suffering from this deficit. The determination of vitamin B12 every 1 year is recommended in patients with T2D treated with metformin, and the eventual replacement in case of deficiency. Although there is consensus on the treatment of the deficit, there is still a lack of evidence to make recommendations on a preventive treatment

Dietas vegetarianas en niños: conocimientos de pediatras de la Sociedad Uruguaya de Pediatría: encuesta 2020 / Vegetarian diet in children: pediatric knowledge from the Uruguayan Society of Pediatrics: 2020 survey / Dietas vegetarianas em crianças: conhecimento dos pediatras da Sociedade Uruguaia de Pediatria: inquérito 2020

Introducción: en los últimos años el incremento de vegetarianos es considerable. Se debe tener cautela al incorporar este tipo de dietas en la población pediátrica. No son contempladas en las actuales guías de nutrición nacionales, generando incertidumbre al realizar recomendaciones. Objetivo: describir los conocimientos sobre dietas vegetarianas en niños por parte de médicos pediatras, posgrados y residentes socios de la Sociedad Uruguaya de Pediatría en el período de junio-setiembre 2020. Determinar la necesidad de incorporar dietas vegetarianas a las guías uruguayas de nutrición pediátrica por parte de los encuestados. Material y método: estudio observacional descriptivo, tipo encuesta transversal, en el período entre junio y setiembre de 2020. Los criterios de inclusión fueron médicos residentes/posgrados en pediatría y pediatras de la Sociedad Uruguaya de Pediatría, de Montevideo y el interior del país. La fuente de datos fue una encuesta online anónima. El análisis de datos fueron frecuencias relativas y absolutas para variables cualitativas. Resultados: se enviaron 1.080 encuestas online, de las que se incluyeron 119. Sobre la autopercepción en el conocimiento de los encuestados, el 58,0% se calificó dentro del rango medio. Acerca del concepto de dieta ovolactovegetariana, 63,9% seleccionó la opción correcta. Más de 50,0% respondió correctamente acerca de conocimientos sobre nutrientes en la mayoría de los ítems. Iniciar estas dietas en la alimentación complementaria fue desaconsejado por el 58% de los socios. Un 79,8% pretende adquirir más conocimientos del tema. Conclusiones: más de la mitad de los profesionales tiene los conocimientos correctos acerca de la correcta planificación y suplementación de dietas vegetarianas en niños. Se destaca la necesidad de incluir dietas vegetarianas en las guías de alimentación pediátrica en territorio uruguayo.

Introduction: the number of vegetarian people has increased considerably in recent years. Caution is suggested when incorporating this type of diet to the pediatric population. This diet has not been contemplated in the current national nutritional guidelines, generating uncertainty among pediatricians when making recommendations. Objective: describe the knowledge Pediatric Physicians and graduate / resident members of the Uruguayan Society of Pediatrics have regarding vegetarian diets in children during the period June-September 2020. Determine the need of the participants of the survey to incorporate vegetarian diet information into the Uruguayan Pediatric Nutritional Guidelines. Materials and methods: descriptive observational study, cross-sectional survey carried out from June to September 2020. The inclusion criteria included resident doctors / postgraduate pediatricians and pediatricians from the Uruguayan Society of Pediatrics of Montevideo and the interior of the country. The data source was an anonymous online survey. The data analyses were relative and absolute frequencies of qualitative variables. Results: 1.080 online surveys were sent and 119 were included. Regarding the respondents' self-perception of knowledge, 58.0% were rated within the medium range. Regarding the concept of lacto-ovo-vegetarian diet, 63.9% selected the correct option. Regarding knowledge about nutrients, we obtained more than 50.0% of correct answers in most of the items. Starting these diets as supplementary food was discouraged by 58% of the participants. 79.8% expressed the intention to acquire more knowledge regarding the subject. Conclusions: more than half of the professionals have the correct knowledge about the correct planning and supplementation of vegetarian diets in children. They stressed the need to include vegetarian diets in pediatric food guidelines in Uruguay.

Introdução: nos últimos anos, o aumento das pessoas vegetarianas tem sido considerável. Deve-se ter cuidado ao incorporar esse tipo de dieta na população pediátrica. Ela não está incluída nas atuais diretrizes nacionais de nutrição, gerando incerteza nos pediatras no momento de fazer recomendações. Objetivo: descrever o conhecimento sobre dietas vegetarianas em crianças dos Pediatras e pós-graduados/residentes da Sociedade Uruguaia de Pediatria no período de junho a setembro de 2020 para poder determinar a necessidade de incorporar dietas vegetarianas às diretrizes nutricionais pediátricas uruguaias. Material e métodos: estudo observacional descritivo, tipo de pesquisa transversal realizada no período de junho a setembro de 2020. Os critérios de inclusão foram médicos residentes/pós-graduados em pediatria e pediatras da Sociedade Uruguaia de Pediatria, Montevidéu e interior do país. A fonte de dados foi uma pesquisa on-line anônima sobre a necessidade de incorporar dietas vegetarianas às diretrizes uruguaias para nutrição pediátrica. As análises dos dados foram frequências relativas e absolutas de variáveis qualitativas. Resultados: 1.080 pesquisas online foram enviadas e 119 foram incluídas. Quanto à autopercepção de conhecimento dos entrevistados, 58,0% foram avaliados dentro da faixa média. Quanto ao conceito de dieta lacto-ovo-vegetariana, 63,9% selecionaram a opção correta. Quanto ao conhecimento sobre nutrientes, obtivemos mais de 50,0% das respostas corretas na maioria dos itens. O início dessas dietas como alimentos suplementares foi desencorajado por 58% dos participantes. 79,8% expressaram a intenção de adquirir mais conhecimento sobre o assunto. Conclusões: mais da metade dos profissionais têm o conhecimento correto sobre o planejamento correto e suplementação de dietas vegetarianas em crianças. Eles enfatizaram a necessidade de incluir dietas vegetarianas nas diretrizes de alimentos pediátricos no Uruguai.

Anemia megaloblástica. A propósito de un caso / Megaloblastic anemia

La OMS reporta anemia en 24,8% de la población con predominio en países en desarrollo. La anemia megaloblástica, es una causa frecuente en la población adulta mayor. Se caracteriza por alteración en la síntesis de ácido desoxirribonucleico por deficiencia de vitamina B12 y/o folatos. Presentamos el caso de una mujer con manifestaciones clínicas y alteraciones de laboratorio características. Recibió tratamiento combinado con cianocobalamina y ácido fólico. Paulatinamente presentó reversión clínica y laboratorial. A pesar del nombre, la anemia megaloblástica, suele cursar con anemia, bicitopenia o ancitopenia y alteraciones sistémicas. Es obligatorio buscar la causa desencadenante para instaurar el tratamiento completo.

The WHO reports anemia in 24.8% of the population mainly in developing countries. Megaloblastic anemia is a frequent cause in the elderly population and it is due to an impaired synthesis of deoxyribonucleic acid. A deficiency of vitamin B12 and / or folic acid are the main causes. We present the case of a woman with characteristic clinical manifestations and laboratory abnormalities. She was treated with cyanocobalamin and folic acid. She improved and her laboratory tests got to normal gradually. Despite the name, megaloblastic anemia usually presents anemia, bicytopenia or pancytopenia and systemic manifestations. It is mandatory to search for the etiologic cause to make a complete treatment.

Tratamiento de la estomatitis aftosa recurrente en pacientes inmunocomprometidos. Revisión sistemática / Treatment of recurrent aphthous stomatitis in immunocompromised patients. Systematic review

RESUMEN Fundamento: Aunque la estomatitis aftosa recurrente no tiene una etiología bien definida porque es una enfermedad multicausal, se ha reconocido que las interacciones o el debilitamiento del sistema inmunitario, contribuyen principalmente a la magnitud del proceso patológico. Las propuestas de tratamiento en pacientes inmunocomprometidos son diversas y por lo general se centran en alteraciones inmunológicas específicas. Objetivo: Evaluar el efecto clínico de los tratamientos propuestos para la estomatitis aftosa recurrente en pacientes inmunocomprometidos. Metodología: La búsqueda se realizó en las bases de datos PubMed/Medline y Cochrane. Se incluyeron ensayos clínicos que tuviesen entre sus variables de respuesta principales: Cicatrización de la úlcera aftosa, tiempo de cicatrización, de recurrencia e intensidad del dolor y entre las variables secundarias: Los efectos adversos y los síntomas. La extracción de datos se realizó de manera independiente por los autores. Se aplicó la metodología por la colaboración Cochrane para evaluar el riesgo de sesgo en cada uno de los estudios. Resultados: Se incluyeron 11 ensayos clínicos (8 controlados) publicados entre 1995 y 2020 y que aportan resultados de la eficacia de varias intervenciones terapéuticas: talidomida (4), irsogladine (2), rebamipida (1), láser de diodo (1), cápsulas de Omega-3 (1), vitamina B 12 (1), Complejo B (1). Seis de estos estudios incluyeron pacientes con la forma menor de estomatitis aftosa recurrente. El periodo de seguimiento estuvo entre los 14 y 360 días. Conclusiones: La talidomida puede ser eficaz en el alivio de los síntomas, la cicatrización y remisión de las lesiones, el diodo de láser y vitamina B12 en la disminución de la intensidad del dolor.

ABSTRACT Background: Although recurrent aphthous stomatitis does not have a well-defined etiology due to it is a multicausal disease, it has been recognized that the interactions or the weakening of the immune system, contribute mainly to the magnitude of the process pathological. Treatment proposals in immune compromised patients are diverse and they usually focus on specific immunological alterations. Objective: To evaluate the clinical effect of the proposed treatments for recurrent aphthous stomatitis in immunocompromised patients. Methodology: The search was performed in the PubMed/Medline and Cochrane databases. Clinical trials were included that could have among their main response variables: Aphthous ulcer healing, healing time, recurrence and pain intensity and among the secondary variables: Adverse effects and symptoms. data extraction was done independently by the authors. The methodology was applied by Cochrane collaboration to assess the risk of bias in each of the studies. Results: 11 clinical trials (8 controlled) published between 1995 and 2020 and that provided the results of the efficacy of various therapeutic interventions: thalidomide (4), irsogladine (2), rebamipide (1), diode laser (1), Omega-3 capsules (1), vitamin B 12 (1), Complex B (1). Six of these studies included patients with the minor form of stomatitis recurrent aphthous. The follow-up period was between 14 and 360 days. Conclusions: Thalidomide may be effective in relieving symptoms, healing and remission of the lesions, the laser diode and vitamin B12 in the decrease of the intensity of the pain.

Avaliação da deficiência de vitamina B12 em idosos usuários e não usuários de metformina / Assessment of B12 deficiency in older adults using metformin or not

Introdução: Sendo a metformina um dos principais tratamentos para o Diabetes Mellitus, torna-se necessário verificar seus efeitos colaterais. A redução nos níveis de vitamina B12 está entre os causadores de consequências importantes na população. Este estudo objetivou determinar o nível de vitamina B12 em usuários e não usuários de metformina de um ambulatório de geriatria no sul de Santa Catarina e avaliar fatores que possam interferir no nível desta vitamina. Métodos: Caracteriza-se como pesquisa quantitativa, observacional, retrospectiva, com coleta de dados secundários. Foram incluídos na pesquisa pacientes idosos com níveis de vitamina B12 documentados em prontuário e excluídos prontuários com ausência de dados e pacientes que fazem suplementação da vitamina. Após a seleção, foram analisados 131 prontuários de pacientes atendidos no período de 2016 e 2017 no Ambulatório de Geriatria das Clínicas Integradas de Saúde da Universidade do Extremo Sul Catarinense. Resultados: Dos pacientes que possuem deficiência de vitamina B12, 26,4% fazem uso de metformina. Dos pacientes que usam metformina, 36,8% possuem deficiência de vitamina B12. No uso de IBP, 39,6% apresentaram deficiência, e naqueles em uso concomitante de metformina e IBP, 9,4% apresentaram deficiência da vitamina. Conclusão: Apesar dos testes estatísticos não apresentarem associação estatisticamente significativa entre o uso de metformina e a deficiência de vitamina B12, os dados do presente estudo mostraram prevalência de deficiência da vitamina na amostra (40,4%). Sugere-se que isso é uma consequência importante da droga e mostra a necessidade de novos estudos na deficiência da vitamina e as suas consequências.

Introduction: As metformin is one of the main treatment options for diabetes mellitus, it is necessary to analyze its side effects. A reduction in B12 levels is one of the causes of important consequences to the population. This study aimed to determine B12 levels in patients who used metformin and those who did not in a geriatric outpatient clinic in southern Santa Catarina, assessing factors that could interfere with the levels of this vitamin. Methods: This is a quantitative, observational, retrospective study, with secondary data collection. We included older patients with B12 levels registered in their medical records and excluded records with missing data and patients who did vitamin replacement. After patient selection, we analyzed 131 medical records of patients seen between 2017 and 2017 at the geriatric outpatient clinic of Clínicas Integradas de Saúde, at Universidade do Extremo Sul Catarinense. Results: Among patients with B12 deficiency, 26.4% used metformin. Out of those using metformin, 36.8% had vitamin B12 deficiency. Among those who used proton-pump inhibitors (PPI), 39.6% had a vitamin deficiency, and considering those who simultaneously used metformin and PPI, 9.4% had a vitamin deficiency. Conclusion: Although statistical tests did not identify a statistically significant association between metformin use and vitamin B12 deficiency, our data showed a prevalence of vitamin deficiency in our sample (40.4%). We suggest that this could be an important consequence of this medication and highlight the need for new studies on B12 deficiency and its consequences.

Efficacy of laparoscopic proximal gastrectomy with double-tract reconstruction versus laparoscopic total gastrectomy with Roux-en-Y reconstruction for early upper gastric cancer / 中华胃肠外科杂志

Objective: To compare clinical efficacy between laparoscopic radical proximal gastrectomy with double-tract reconstruction (LPG-DTR) and laparoscopic radical total gastrectomy with Roux-en-Y reconstruction (LTG-RY) in patients with early upper gastric cancer, and to provide a reference for the selection of surgical methods in early upper gastric cancer. Methods: A retrospective cohort study method was carried out. Clinical data of 80 patients with early upper gastric cancer who underwent LPG-DTR or LTG-RY by the same surgical team at the Department of General Surgery, the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to January 2021 were retrospectively analyzed. Patients were divided into the DTR group (32 cases) and R-Y group (48 cases) according to surgical procedures and digestive tract reconstruction methods. Surgical and pathological characteristics, postoperative complications (short-term complications within 30 days after surgery and long-term complications after postoperative 30 days), survival time and nutritinal status were compared between the two groups. For nutritional status, reduction rate was used to represent the changes in total protein, albumin, total cholesterol, body mass, hemoglobin and vitamin B12 levels at postoperative 1-year and 2-year. Non-normally distributed continuous data were presented as median (interquartile range), and the Mann-Whitney U test was used for comparison between groups. The χ(2) test or Fisher's exact test was used for comparison of data between groups. The Mann-Whitney U test was used to compare the ranked data between groups. The survival rate was calculated by Kaplan-Meier method categorical, and compared by using the log-rank test. Results: There were no statistically significant differences in baseline data betweeen the two groups, except that patients in the R-Y group were oldere and had larger tumor. Patients of both groups successfully completed the operation without conversion to laparotomy, combined organ resection, or perioperative death. There were no significant differences in the distance from proximal resection margin to superior margin of tumor, postoperative hospital stay, time to flatus and food-taking, hospitalization cost, short- and long-term complications between the two groups (all P>0.05). Compared with the R-Y group, the DTR group had shorter distal margins [(3.2±0.5) cm vs. (11.7±2.0) cm, t=-23.033, P<0.001], longer surgery time [232.5 (63.7) minutes vs. 185.0 (63.0) minutes, Z=-3.238, P=0.001], longer anastomosis time [62.5 (17.5) minutes vs. 40.0 (10.0) minutes, Z=-6.321, P<0.001], less intraoperative blood loss [(138.1±51.6) ml vs. (184.3±62.1) ml, t=-3.477, P=0.001], with significant differences (all P<0.05). The median follow-up of the whole group was 18 months, and the 2-year cancer-specific survival rate was 97.5%, with 100% in the DTR group and 95.8% in the R-Y group (P=0.373). Compared with R-Y group at postoperative 1 year, the reduction rate of weight, hemoglobin and vitamin B12 were lower in DTR group with significant differences (all P<0.05); at postoperative 2-year, the reduction rate of vitamin B12 was still lower with significant differences (P<0.001), but the reduction rates of total protein, albumin, total cholesterol, body weight and hemoglobin were similar between the two groups (all P>0.05). Conclusions: LPG-DTR is safe and feasible in the treatment of early upper gastric cancer. The short-term postoperative nutritional status and long-term vitamin B12 levels of patients undergoing LPG-DTR are superior to those undergoing LTG-RY.

Serum Vitamin B12 Level and Dietary intake in Adult Atopic Dermatitis: A Case Control Study

Background@#Vitamin B12 is a contributing factor in pruritus and peripheral nerve regeneration. Its role in atopic dermatitis (AD) is still unclear. This study aimed to compare vitamin B12 level between AD patients and healthy controls, determine its correlation with pruritus and AD severity, and evaluate dietary pattern with energy, macro and micronutrient intakes.@*Methods@#This was a case control study involving adult AD patients and age-, gender-, ethnicity- and body mass index-matched healthy controls. All adult patients who fulfilled UK Working Party AD diagnostic criteria were included. Exclusion criteria include patients on systemic agents, diseases known to affect B12 level and vegan diet. AD severity was determined using SCORing Atopic Dermatitis (SCORAD) index. Serum vitamin B12 level were measured. A three-day 24-hour dietary recall was collected and analyzed.@*Results@#A total of 42 AD patients and 42 controls were recruited. Mean SCORAD index was 39.2±16.6, and AD duration was 12.7 ± 8.1 years. Vitamin B12 was lower among AD (215.6 ± 110.2 pmol/L) versus control (295.1± 119.9 pmol/L), p<0.01 despite similar dietary B12 intake in both groups. There were no significant correlations between AD duration and severity with vitamin B12 level. Energy intake (kcal/ day) was significantly lower in AD (p=0.04). There were no significant differences in proportion of main food groups consumed and other macronutrient and micronutrient intakes.@*Conclusion@#Serum vitamin B12 level was significantly lower in AD patients despite similar dietary pattern and nutrient intake with healthy controls. There were no correlations with AD severity or disease duration. Dietary pattern of AD patients should be routinely assessed to ensure adequate nutrition.

Economic impact of gastrointestinal nematodes in Morada Nova sheep in Brazil / Impacto econômico de nematódeos gastrintestinais em ovinos Morada Nova no Brasil

Abstract This study evaluated the economic impact of gastrointestinal nematode (GIN) infection in Morada Nova lambs under different parasite chemical control conditions. For this, 246 lambs, in the rainy and dry season, were randomized into groups according to their anthelmintic treatment with levamisole: control (CT: no treatment); routine treatment (RT: treated every 42 days); and targeted selective treatment (TST: treated according to the average daily weight gain, DWG). From 63 days of age (D63) to D210, the lambs were weighed and monitored for GIN infection parameters. Spending on anthelmintics in the production system was 1.3% of the total economic result. The economic result per animal (R$ 5.00 = US$ 1.00) was higher in the RT group, amounting to US$ 6.60 in the rainy and US$ 5.69 in the dry season, due to higher DWG. Thus, RT presented economic results 14.4% and 10.9% higher than CT, and 7.2% and 1.9% higher than TST, in the rainy and dry season, respectively. However, fast development of resistance made RT unfeasible. Here, the economic impact of GIN infection on a national scale is discussed, demonstrating its importance and the impossibility of profitable and sustainable sheep production without adequate control.

Resumo Este estudo avaliou o impacto econômico da infecção por nematoides gastrintestinais (NGI), em cordeiros Morada Nova, sob diferentes condições de controle químico dos parasitas. Para isso, 246 cordeiros, na estação chuvosa e seca, foram randomizados em grupos de acordo com o tratamento com levamisol: controle (TC: sem tratamento); tratamento rotineiro (TR: tratado a cada 42 dias); e tratamento seletivo direcionado (TST: tratado de acordo com o ganho de peso médio diário, GMD). Dos 63 dias de idade (D63) ao D210, os cordeiros foram pesados ​​e monitorados quanto aos parâmetros de infecção por NGI. O gasto com anti-helmínticos no sistema produtivo foi de 1,3% do resultado econômico total. O resultado econômico por animal (R$ 5,00 = US$ 1,00) foi maior no grupo RT, totalizando US$ 6,60 na estação chuvosa e US$ 5,69 na seca, devido ao maior GMD. Assim, o RT apresentou resultados econômicos 14,4% e 10,9% superiores ao TC, e 7,2% e 1,9% superiores ao TST, no período chuvoso e seco, respectivamente. Entretanto o rápido desenvolvimento de resistência inviabiliza o TR. O impacto econômico da infecção por NGI em escala nacional são aqui discutidos, demonstrando sua importância e a impossibilidade de uma ovinocultura lucrativa e sustentável sem o controle adequado.

Cobalamin cbiP mutant shows decreased tolerance to low temperature and copper stress in Listeria monocytogenes

BACKGROUND: Listeria monocytogenes is a foodborne pathogen that causes listeriosis in humans. This pathogen activates multiple regulatory mechanisms in response to stress, and cobalamin biosynthesis might have a potential role in bacterial protection. Low temperature is a strategy used in the food industry to control bacteria proliferation; however, L. monocytogenes can grow in cold temperatures and overcome different stress conditions. In this study we selected L. monocytogenes List2-2, a strain with high tolerance to the combination of low temperature +copper, to understand whether the cobalamin biosynthesis pathway is part of the tolerance mechanism to this stress condition. For this, we characterized the transcription level of three cobalamin biosynthesis related genes ( cbiP , cbiB, and cysG ) and the eutV gene, a transcriptional regulator encoding gene involved in ethanolamine metabolism, in L. monocytogenes strain List2-2 growing simultaneously under two environmental stressors: low temperature (8 °C) +copper (0.5 mM of CuSO4 ×5H2O). In addition, the gene cbiP , which encodes an essential cobyric acid synthase required in the cobalamin pathway, was deleted by homologous recombination to evaluate the impact of this gene in L. monocytogenes tolerance to a low temperature (8 °C) +different copper concentrations. RESULTS: By analyzing the KEGG pathway database, twenty-two genes were involved in the cobalamin biosynthesis pathway in L. monocytogenes List2-2. The expression of genes cbiP , cbiB, and cysG, and eutV increased 6 h after the exposure to low temperature +copper. The cobalamin cbiP mutant strain List2-2Δ cbiP showed less tolerance to low temperature +copper (3 mM) than the wild type L. monocytogenes List2-2. The addition of cyanocobalamin (5 nM) to the medium reverted the phenotype observed in List2-2Δ cbiP . CONCLUSION: These results indicate that cobalamin biosynthesis is necessary for L. monocytogenes growth under stress and that the cbiP gene may play a role in the survival and growth of L. monocytogenes List2-2 at low temperature +copper.

Déficit de vitamina B12 en grupos vulnerables con alimentación omnívora / Vitamin B12 deficiency in vulnerable groups with omnivorous diet

Introducción: la vitamina B12 cumple un rol esencial en el crecimiento y el neurodesarrollo. El déficit de vitamina B12 (B12) es un problema de salud pública en Argentina, con una alta prevalencia en población de riesgo, como las embarazas y niños en situación social vulnerable, aunque mantengan una dieta omnívora. Objetivos: actualizar la información disponible sobre la deficiencia de B12 en la población vulnerable con el fin de resaltar y actualizar la importancia del tema para realizar un diagnóstico temprano, un tratamiento oportuno y prevenir las complicaciones irreversibles. Resultados: es importante que el pediatra conozca las diferentes formas de presentación del déficit de B12 y principalmente que se considere como diagnóstico diferencial ante niños con alteraciones neurológicas, aún en ausencia de anemia, para lograr intervenciones tempranas que disminuyan el impacto de la enfermedad. Varios investigadores concluyeron que un marcador aislado puede conducir a diagnósticos erróneos, por lo cual actualmente lo más recomendado es usar al menos dos. De los tratamientos evaluados, la mayoría acuerda en realizar entre siete a 10 días de tratamiento, con 1 mg de B12, ya sea intramuscular o vía oral, seguido de tres a 11 semanas de tratamiento semanal. Conclusiones: es de vital importancia relevar datos actualizados de prevalencia de déficit en el país, como así también implementar intervenciones terapéuticas y de políticas públicas preventivas

Introduction: vitamin B12 plays an essential role in growth and neurodevelopment. Vitamin B12 deficiency is a public health problem in Argentina, with a high prevalence in a highrisk population, such as pregnant women and children with a vulnerable social situation, although their omnivorous diet. Objectives: to update the information available on vitamin B12 deficiency in vulnerable populations, in order to highlight the importance of the subject, to achieve an early diagnosis and timely treatment and thus prevent irreversible complications. Results: it is important that the pediatrician knows the different types of vitamin B12 deficiency presentation and to consider it as a differential diagnosis in children with neurological symptoms, even in the absence of anemia, to achieve early interventions and diminish the burden of disease. Many researchers have concluded that an isolated marker can lead to misdiagnoses, so it is currently recommended to use at least two. Most of the treatments evaluated, agree on the administration of 1 mg of B12, for 7 to 10 days, either intramuscular or orally, followed by 3 to 11 weeks of a weekly dose. Conclusions: it is important to update data on the prevalence of B12 deficiency in our country, as well as the implementation of therapeutic interventions and preventive public policies