Two parenteral amino acid solutions and plasma levels of amino acids in the neonate: A randomized trial.

OBJECTIVE: In neonates on total parenteral nutrition (TPN), amino acids may be a risk factor for developing total parenteral nutrition-associated cholestasis (TPNAC). We aimed, first, to compare methionine, cysteine, and taurine plasma levels between neonates on TPN who were receiving an intravenous amino acid solution based on a breast milk aminogram and those on an intravenous solution of pediatric amino acids based on an umbilical cord aminogram, and second, to determine the frequency of TPNAC. METHODS: A double-blind randomized controlled trial was conducted. Ninety-four neonates with a birthweight of 1000g or more and a gestational age of 30 wk or older were admitted and enrolled. Blood samples were obtained at 0, 7, and 14 d of TPN, and plasma amino acid concentrations were determined by ultra-high-resolution liquid chromatography. Continuous variables were compared using the Wilcoxon rank-sum test or Student's t test; categorical variables were compared using the Fisher exact test. RESULTS: Thirty-five neonates completed the study (Primene, n = 14; TrophAmine, n = 21). On day 14, methionine plasma concentrations were significantly lower in the Primene group than in the TrophAmine group (27 µmol/L versus 32.9 µmol/L, P = 0.044); the taurine concentration was significantly higher in the same group (72.4 µmol/L versus 45.3 µmol/L, P < 0.0001). There were no differences in TPNAC incidence. CONCLUSIONS: Administering an intravenous solution of pediatric amino acids based on the umbilical cord aminogram yielded a higher taurine and lower methionine plasma concentration than did administering a similar solution based on the breast milk aminogram.

Assessing medical student documentation using simulated charts in emergency medicine.

BACKGROUND: The 1995 Health Care Financing Administration (HCFA) guidelines stated that providers may only use the review of systems and past medical, family, social history in student documentation for billing purposes; therefore, many providers viewed the student documentation as an extraneous step and chose not to allow medical students to document patient visits. This workflow negatively affected medical student education in documentation skills. Although the negative impact on students' documentation skills is obvious, areas of deficits are unknown. Understanding the area of deficits will benefit future curriculums to prepare prospective resident physicians for proper documentation. We aimed to assess areas of deficits in documentation of fourth-year medical students according to HCFA billing guidelines. METHODS: We conducted a prospective study of fourth-year medical students' simulated chart documentations at a United States medical school from May 2014 to May 2015. We evaluated students' simulated charts from an online learning tool using simulated cases for completeness according to HCFA guidelines and analyzed data using descriptive statistics. RESULTS: We found that 98.9% (n = 90) of the charts were downcoded. Of these charts, 33.0% (n = 30) had incomplete history of present illness, 90.1% (n = 82) had incomplete review of systems, 73.6% (n = 67) had incomplete past medical, family, social history and 88.8% (n = 80) had incomplete physical exams. CONCLUSION: New curriculum should include billing guideline information and emphasize the completeness of charts according to acuity.

Improving feedback by using first-person video during the emergency medicine clerkship.

PURPOSE: Providing feedback to students in the emergency department during their emergency medicine clerkship can be challenging due to time constraints, the logistics of direct observation, and limitations of privacy. The authors aimed to evaluate the effectiveness of first-person video, captured via Google Glass™, to enhance feedback quality in medical student education. MATERIAL AND METHODS: As a clerkship requirement, students asked patients and attending physicians to wear the Google Glass™ device to record patient encounters and patient presentations, respectively. Afterwards, students reviewed the recordings with faculty, who provided formative and summative feedback, during a private, one-on-one session. We introduced the intervention to 45, fourth-year medical students who completed their mandatory emergency medicine clerkships at a United States medical school during the 2015-2016 academic year. RESULTS: Students assessed their performances before and after the review sessions using standardized medical school evaluation forms. We compared students' self-assessment scores to faculty assessment scores in 14 categories using descriptive statistics and symmetric tests. The overall mean scores, for each of the 14 categories, ranged between 3 and 4 (out of 5) for the self-assessment forms. When evaluating the propensity of self-assessment scores toward the faculty assessment scores, we found no significant changes in all 14 categories. Although not statistically significant, one fifth of students changed perspectives of their clinical skills (history taking, performing physical exams, presenting cases, and developing differential diagnoses and plans) toward faculty assessments after reviewing the video recordings. CONCLUSION: First-person video recording still initiated the feedback process, allocated specific time and space for feedback, and possibly substituted for the direct observation procedure. Additional studies, with different outcomes and larger sample sizes, are needed to understand the effectiveness of first-person video in improving feedback quality.

Maíz nixtamalizado suplementado con un concentrado de proteínas de sardina para mejorar el valor biológico de las tortillas.

INTRODUCCIÓN: La mayor parte de la población rural en México adquiere casi la mitad de su energía de la tortilla de maíz y sus fuentes de proteína son principalmente de origen vegetal. OBJETIVO: Obtener un concentrado de proteína de sardina para adicionar harina de maíz e identificar la concentración que proporcione la mejor calidad biológica de las tortillas sin modificar sus características físicas y sensoriales. MÉTODO: Obtención de un concentrado de proteína de sardina y elaboración de tortillas con harina de maíz suplementada con diferentes concentraciones de proteína. Las características físicas y sensoriales de las tortillas fueron evaluadas por panelistas no entrenados. La calidad biológica de las tortillas se analizó en un modelo murino (crecimiento y la relación de eficiencia de proteína, PER). Para el análisis se utilizó estadística paramétrica. RESULTADOS: Se obtuvo un concentrado de proteína con 70.48 g/100 g. La suavidad, inflado, doblado y calidad de las tortillas preparadas con las mezclas con 0.63-3.75 % de proteínas de sardina fueron comparables con los de las tortillas elaboradas con harina no adicionada. El crecimiento de las ratas alimentadas con tortillas adicionadas fue mayor que el de las alimentadas con harina no adicionada; la diferencia fue significativa a partir de la concentración de 3.75 % (p < 0.05). El PER de las tortillas con 3.75 % de proteínas de sardina fue de 2.41, comparable al de la proteína de referencia (caseína). CONCLUSIÓN: La harina de maíz adicionada con proteínas de sardina en una proporción de 96.25:3.75 % mejora el valor biológico de las tortillas sin alterar sus características físicas y sensoriales. INTRODUCTION: Most part of the rural population in Mexico obtains almost half its energy from corn tortilla, and its sources of protein are mainly of vegetal origin. OBJECTIVE: To obtain a concentrate of sardine protein (SP) to supplement corn flour, and to identify which concentration provides corn tortillas with a better biological value, without modifying its physical and sensorial characteristics. METHOD: Obtainment of the SP concentrate, preparation of tortillas with corn flour and different SP concentrations, assessment of tortillas physical and sensorial characteristics by untrained panelists, assessment of biological quality in a murine model (growth and protein efficiency ratio [PER]). Parametric statistics was used. RESULTS: A protein concentrate of 70.48 g/100 g was obtained. Smoothness, blistering, foldability and quality of the tortillas prepared with mixtures containing 0.63-3.75% of SP were comparable to those of tortillas prepared with non-supplemented flour. The growth of rats fed supplemented tortillas was superior; the difference was significant with ≥ 3.75% concentrations (p < 0.05). The PER of tortillas with 3.75% of SP was 2.41, which was comparable to that of the reference protein (casein). CONCLUSION: SP-supplemented corn flour at a 96.25:3.75% ratio improves the biological value of tortillas without modifying their physical and sensorial characteristics.

Longitudinal Analysis of the Interaction Between Obesity and Pregnancy on Iron Homeostasis: Role of Hepcidin.

BACKGROUND AND AIMS: When pregnancy occurs in obese women, two opposite mechanisms for iron homeostasis concur: increased need for available iron to support erythropoiesis and decreased iron mobilization from diets and stores due to obesity-related inflammation linked to overexpressed hepcidin. Few studies have examined the role of hepcidin on maternal iron homeostasis in the context of obese pregnancy. The aim of the study was to evaluate the combined effect of maternal obesity and pregnancy on hepcidin and maternal iron status while accounting for inflammation and iron supplementation. METHODS: We conducted a secondary analysis of a cohort of pregnant women recruited from a referral obstetric hospital in Mexico City. Circulating biomarkers of iron status (hepcidin, ferritin [SF], transferrin receptor [sTfR], erythropoietin [EPO]), and inflammation (C-reactive protein [CRP], tumor necrosis factor-[TNF]α, and interleukin-[IL]6) were determined monthly throughout pregnancy. Repeated measures ANOVA and logistic regression models were used for statistics. RESULTS: Twenty-three obese (Ob) and 25 lean (Lc) women were studied. SF and hepcidin declined, and EPO and sTfR increased throughout pregnancy in both groups. sTfR increased more in Ob than in Lc (p = 0.024). The smallest hepcidin decline occurred in iron-supplemented Ob women compared to non-supplemented Lc women (p = 0.022). The risk for iron deficiency at the end of pregnancy was higher for Ob than for Lc (OR = 4.45, 95% CI = 2.07-9.58) after adjusting for iron supplementation and hepcidin concentration. CONCLUSION: Pre-gestational obesity increases the risk of maternal iron deficiency despite iron supplementation. Overexpressed hepcidin appears to be a potential mechanism.

[Interactions between markers of endothelial damage (homocysteine and asymmetric dimethylarginine) and antioxidants and B-vitamins in preeclamptic women]. / Interacción entre los marcadores de daño endotelial (homocisteóna y dimetilarginina asimétrica) con las vitaminas antioxidantes y del grupo B en pacientes con preeclampsia.

BACKGROUND: Preeclampsia is a pregnancy-related pathological condition triggered by an abnormal placentation which produces endothelial dysfunction (ED). ED, in turn, is associated with an increase in homocysteine (hcy) and asymmetric dimethylarginine (ADMA); these molecules are also increased when some of the B-vitamins are deficient. It is unclear whether increases in hcy and ADMA during preeclampsia are the result of ED, or the consequence of a B-vitamin deficiency. OBJECTIVE: To evaluate hcy, ADMA, folic acid (FA), vitamin B6 and B2 concentrations in patients with preeclampsia. METHODS: In a cross-sectional design 19 patients with severe preeclamp- sia (preeclampsia) and 57 with normal pregnancy (no-preeclampsia), paired by gestational age and body mass index, were studied. Plasma hcy, ADMA, FA and vitamins B6 and B12 were determined. Non-parametric statistics was used for between-groups comparisons and regression analyses to evaluate interactions among molecules. RESULTS: 72% of women were vitamin B deficient, 40% were deficient of B12 and 4% of FA. Preeclamptic patients presented hcy and ADMA concentrations higher than no-preeclamptic ones. Inferential analyses demonstrated that: hcy and ADMA are increased during preeclampsia independently from vitamins blood concentration; that the risk for pre- eclampsia is associated with high hcy but not with vitamins deficiency; and that the ratio L-arginine:ADMA decreases the preeclampsia risk. CONCLUSION: In patients with preeclampsia, increases of hcy and ADMA are associated with ED, but not with deficiency of the vitamins involved in their metabolism.

Validity and reliability of the 13C-methionine breath test for the detection of moderate hyperhomocysteinemia in Mexican adults.

BACKGROUND: Hyperhomocysteinemia (Hhcy) is considered an independent risk factor for vascular diseases and, more recently, for dementia. The methionine loading test (MLT) is useful for diagnosing additional subjects with moderate Hhcy. However, it is a complex and time-consuming procedure. A noninvasive test for the diagnosis of moderate Hhcy is desirable. METHODS: The study protocol consisted of three consecutive visits. During the first visit, we performed an MLT to characterize the Hhcy status of 75 healthy adult subjects. For the breath test protocol, we selected a subsample and assigned to the control group 17 subjects with fasting and post-loading homocysteine (Hcy) ≤12 and <42.3 µmol/L, respectively, and to the Hhcy group 16 subjects with fasting Hcy ≤12 and >42.3 µmol/L after loading. Selected subjects were requested to have a second visit to perform a breath test within 1-4 weeks following the MLT test and received an oral dose of 2.5 mg/kg of 1-13C-methionine dissolved in water. Breath samples were collected at basal, 20, 40, 60, 80, 100 and 120 min (test 1). The same procedure was repeated within 1 week (test 2). RESULTS: MLT was useful for diagnosing almost twice the number of individuals with Hhcy (24%) in comparison with the fasting determination alone (13.3%). The 13C-methionine breath test reported a sensitivity of 81.3% and a specificity of 64.7% against the MLT. The coefficient of variation between breath test 1 and breath test 2 was 9.0±5.4%. CONCLUSIONS: The 13C-methionine breath test is a valid and reliable method for identifying subjects with moderate Hhcy.

[Homocysteine after a methionine load in healthy subjects with adequate B-vitamin status]. / Homocisteína plasmática posterior a carga oral de metionina en sujetos sanos con nivel adecuado de vitaminas B.

BACKGROUND: Plasma homocysteine (Hcy) determination at 6-8 h after an oral methionine load (OML) allows for identification of some, but not all, individuals at risk to develop cardiovascular disease. It is probable that in some cases the Hcy increases occur later, or it elevates between normal ranges but in a sustained manner. However, the entire Hcy response curve has not been described. We undertook this study to determine Hcy concentrations from baseline to 24- and 48-h after an OML in non-B-vitamin deficient adult subjects with other risk factors for high levels of Hcy such as smoking and overweight. METHODS: In a cross-over, clinical design, Hcy concentrations were determined at 2-h intervals throughout 12 h and at 24 h and 48 h after an OML (0.1 g/kg). Hcy and vitamin B6 (VB6) concentrations were measured by high-performance liquid chromatography (HPLC). Folic acid (FA) and vitamin B12 (VB12) were measured by radioimmunoassay (RIA). Statistical analysis included delta values and areas under the curve. Student t-test and repeated measurement analyses were conducted to control for confounders. RESULTS: Twenty-nine subjects with adequate Hcy, FA, VB6 and VB12 status were included. The maximum Hcy concentration occurred 8 h after the load and returned to baseline concentrations after 24 h. All subjects presented Hcy after the load within normal ranges, but smoking and overweight synergistically influenced the response to the challenge, producing a sustained elevation after the dose. CONCLUSIONS: Hcy concentrations after an OML remained above baseline for at least 24 h. Smoking and overweight affected the response to the methionine challenge.

[Serum levels of antioxidants and vitamins related to the homocystein's metabolism during postmenopause]. / Concentraciones séricas de vitaminas antioxidantes y vitaminas relacionadas con el metabolismo de la homocisteína durante la posmenopausia.

OBJECTIVE: To describe nutritional status, B6, B12, and antioxidant vitamins, as well as homocysteine concentrations in postmenopausal women. PATIENTS AND METHODS: A cross-sectional study was conducted in Mexico City. One hundred twenty-five women were selected if they were healthy and were in their first five years after menopause onset. Women were spontaneously divided in two groups: women who did not receive any hormonal treatment for at least six months before the study (n = 66), and those who received hormonal treatment at the moment of the study (n = 59). Anthropometry was measured and a fasting blood sample from a peripheral vein was obtained to determine homocysteine, vitamins A, C, E, B6, B12, and folic acid. Results were compared with Student t-test, and a logistic regression model was used to calculate the risk of hyperhomocystinemia after adjusting by some potential confounders. RESULTS: Women who did not receive hormone replacement therapy presented higher body mass index and waist-hip ratio than those who received such treatment. In contrast, this group presented higher prevalence of folic acid deficiency and hyperhomocystinemia, despite they consumed higher amounts of folic acid in the diet. This high risk of hyperhomocystinemia was independent of vitamin serum concentrations and the level of physical activity (OR = 15.1, IC95 = 1.60,141.9). CONCLUSIONS: These results suggest that hormone replacement therapy may protect against overweight and central fat distribution that occur after menopause, but increases the risk of hyperhomocystinemia.

Vitamins A, and C and folate status in Mexican children under 12 years and women 12-49 years: a probabilistic national survey.

OBJECTIVE: To describe the epidemiology of Vitamin A and C and folic acid deficiencies and their association with sociodemographic and dietary factors in a national probabilistic sample of Mexican women and children. MATERIAL AND METHODS: This is a probabilistic sample from the National Nutrition Survey 1999 (ENN-99) including 1,966 children and 920 women. Vitamins A and C were measured in serum by high-performance liquid chromatography, and folic acid in total blood by a microbiological method. Determinants for such deficiencies were explored by multiple regression models. RESULTS: Vitamin A deficiency (retinol < 10 micrograms/dl) was rare in both children and women. But subclinical deficiency (retinol > 10 and < 20 micrograms/dl) was present in 25% of children. The likelihood of subclinical deficiency of vitamin A was less in older children (OR = 0.98, p = 0.01) and in women with higher body mass index (OR = 0.93, p = 0.01). About 30% of children < 2 years of age and 40% of women were vitamin C deficient. The likelihood of vitamin C deficiency was less in children and women as socioeconomic level increased (OR = 0.69, p = 0.03, and OR = 0.80, p = 0.04), and higher in older women (OR = 1.02, p = 0.05). The prevalence of folate deficiency varied in children (2.3 to 11.2), in women it was 5%. Folate deficiency was less in children of higher socioeconomic level (OR = 0.62, p = 0.01), and in those eating more vegetables (OR = 0.22, p = 0.01). CONCLUSIONS: The high prevalence of subclinical deficiency of vitamin A in children is indicative of risk of further deterioration under adverse circumstances. Vitamin C deficiency in both children and women implies in addition diminished ability for iron absorption. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

Vitamins A, and C and folate status in Mexican children under 12 years and women 12-49 years: a probabilistic national survey

OBJETIVO: Describir la epidemiología de las deficiencias de las vitaminas A y C y del ácido fólico, y analizar su asociación con factores sociodemográficos y dietéticos en una muestra probabilística nacional de mujeres y niños mexicanos. Informar acerca del estado nutricio de estas vitaminas en una muestra probabilística nacional en México. MATERIAL Y MÉTODOS: Esta muestra probabilística de la Encuesta Nacional de Nutrición 1999 incluyó 1 966 niños y 920 mujeres. Las concentraciones séricas de las vitaminas A y C fueron medidas por cromatografía líquida de alta resolución HPLC (por sus siglas en inglés) y las de ácido fólico en sangre total por un método microbiológico. Se exploraron los posibles determinantes de la deficiencia de tales nutrimentos mediante modelos de regresión logística. RESULTADOS: La deficiencia de vitamina A (retinol <10 µg/dl) fue rara, tanto en niños como en mujeres. El 25 por ciento de los niños de 1 a 8 años de edad tuvieron deficiencia subclínica (retinol >10 <20 µg/dl). El riesgo de tener deficiencia subclínica de vitamina A fue menor en los niños de mayor edad (OR=0.98, p=0.01) y en mujeres con mayor índice de masa corporal (OR=0.93, p=0.01). El 30 por ciento de los niños <2 años de edad y 40 por ciento de las mujeres tuvieron deficiencia de vitamina C. El riesgo de esta deficiencia fue menor en niños y mujeres de nivel socioeconómico alto (OR=0.69, p=0.03, y OR=0.80, p=0.04), y mayor en mujeres de mayor edad (OR=1.02, p=0.05). En los niños la prevalencia de deficiencia de ácido fólico varió entre 2.3 y 11.2 por ciento, en las mujeres de 5 por ciento. El riesgo de tener deficiencia de folatos fue menor en niños con nivel socioeconómico alto (OR=0.66, p=0.04), y menor en aquellos que consumían más vegetales (OR= 0.22, p=0.01). CONCLUSIONES: La alta prevalencia en México de deficiencia subclínica de vitamina A en niños y de vitamina C tanto en niños como en mujeres reclama acciones programáticas para reducirlas.