¿ Can COVID-19 exacerbate multiple sclerosis symptoms? A case series analysis.

INTRODUCTION: Peripheral inflammation can exacerbate pre-existing lesions in the Central Nervous System (CNS) in the context of neurodegenerative diseases, including Multiple Sclerosis (MS). OBJECTIVE: To analyze the clinical effect of COVID-19 infection, as a generator of peripheral inflammation, in a MS patients group. METHODS: A retrospective analysis of 400 medical records of MS patients from a referral center was carried out. MS patients who presented COVID-19 were surveyed about symptoms exacerbation: type, duration and onset of exacerbation, previous vaccination against COVID-19 and MS severity. Clinical and demographic information from the medical records were included. Descriptive and inferential analysis were performed using the GraphPad Prism V6. RESULTS: 41 patients were included, 61% (n = 25) reported neurological worsening, 9.7% (n = 4) as relapses, and 7.3% (n = 3) required corticosteroids. We found significant differences in the EDSS between patients who exacerbated their MS symptoms and those who did not (p = 0.03). When performing a multivariate regression analysis, we found that EDSS was independently associated with the presence of exacerbations of MS in the context of SARS-CoV2 infection (OR = 2.44, p = 0.022). CONCLUSIONS: This preliminary study suggests that COVID-19 infection could trigger exacerbations of MS symptoms. New studies are needed to elucidate the relationship between COVID-19 and MS.

[Atypical clinical manifestations as a form of presentation in multiple sclerosis]. / Manifestaciones clínicas atípicas como forma de presentación de la esclerosis múltiple.

The atypical clinical features in multiple sclerosis (MS) have been rarely reported and suggest the possibility of an alternative diagnosis. The aim was to describe the clinical and demographic characteristics of MS patients who debuted with atypical symptoms and to estimate the sensitivity, specificity and positive predictive value (PPV) for MS diagnosis. A retrospective analysis of clinical records was performed. The following data were recorded: patients with MS diagnosis according to current diagnostic criteria at the time of diagnosis, type of symptom at the onset, time to second relapse, presence of oligoclonal bands (OCB) in cerebrospinal fluid (CSF) and radiological red flags on MRI. A descriptive and inferential analysis was performed using the chi square test, and sensitivity, specificity and PPV were calculated. Six hundred two patients were diagnosed with MS, of which 22 (3.65%) had an atypical clinical presentation. 54.5% were women. The mean age was 29 years (SD ± 11.7). The most common atypical symptom was peripheral facial palsy (27%). The PPV for atypical onset was 6.14%; p < 0.001. Sensitivity and specificity of these symptoms to MS diagnosis were 3.65% and 19%, respectively. In our research, the presence of atypical symptoms at the onset of MS was very low. Other diseases must be excluded, taking into account their low sensitivity, specificity and PPV.

Las manifestaciones clínicas atípicas al inicio de la esclerosis múltiple (EM) son poco frecuentes y sugieren la posibilidad de un diagnóstico alternativo. El objetivo fue describir las características clínicas en la EM con síntomas atípicos al inicio, y estimar la sensibilidad, especificidad y valor predictivo positivo (VPP) para el diagnóstico de EM. Se trata de un análisis retrospectivo de historias clínicas. Se registraron los siguientes datos: pacientes con diagnóstico de EM acorde a los criterios diagnósticos correspondientes, tipo de síntoma de inicio, tiempo hasta la segunda recaída, presencia de bandas oligoclonales en el líquido cefalorraquídeo (LCR) y de banderas rojas radiológicas en la Resonancia Magnética de encéfalo (RMN). Se realizó un análisis descriptivo e inferencial utilizando la prueba de chi cuadrado y se calcularon la sensibilidad, la especificidad y el VPP. Seiscientos dos pacientes tuvieron un diagnóstico final de EM, de los cuales 22 (3.7%) tuvieron una presentación clínica atípica. El 54.5% eran mujeres. La edad promedio fue de 29 años (DE ± 11.7). El síntoma atípico más frecuente fue parálisis facial periférica aislada (6/22). El VPP para el inicio atípico fue de 6.1%; p < 0001. La sensibilidad y especificidad de estos síntomas al diagnóstico de EM fueron del 3.7% y 19%, respectivamente. En nuestra cohorte, demostramos que la presencia de síntomas atípicos como presentación de la EM es poco frecuente. Es mandatorio la exclusión de otras enfermedades, teniendo en cuenta su baja sensibilidad, especificidad y VPP.

Manifestaciones clínicas atípicas como forma de presentación de la esclerosis múltiple / Atypical clinical manifestations as a form of presentation in multiple sclerosis

Resumen Las manifestaciones clínicas atípicas al inicio de la esclerosis múltiple (EM) son poco frecuentes y sugieren la posibilidad de un diagnóstico alternativo. El objetivo fue describir las características clínicas en la EM con síntomas atípicos al inicio, y estimar la sensibilidad, especificidad y valor predictivo posi tivo (VPP) para el diagnóstico de EM. Se trata de un análisis retrospectivo de historias clínicas. Se registraron los siguientes datos: pacientes con diagnóstico de EM acorde a los criterios diagnósticos correspondientes, tipo de síntoma de inicio, tiempo hasta la segunda recaída, presencia de bandas oligoclonales en el líquido cefalorraquídeo (LCR) y de banderas rojas radiológicas en la Resonancia Magnética de encéfalo (RMN). Se realizó un análisis descriptivo e inferencial utilizando la prueba de chi cuadrado y se calcularon la sensibilidad, la especificidad y el VPP. Seiscientos dos pacientes tuvieron un diagnóstico final de EM, de los cuales 22 (3.7%) tuvieron una presentación clínica atípica. El 54.5% eran mujeres. La edad promedio fue de 29 años (DE ± 11.7). El síntoma atípico más frecuente fue parálisis facial periférica aislada (6/22). El VPP para el inicio atípico fue de 6.1%; p < 0001. La sensibilidad y especificidad de estos síntomas al diagnóstico de EM fueron del 3.7% y 19%, respectivamente. En nuestra cohorte, demostramos que la presencia de síntomas atípicos como presentación de la EM es poco frecuente. Es mandatorio la exclusión de otras enfermedades, teniendo en cuenta su baja sensibilidad, especificidad y VPP.

Abstract The atypical clinical features in multiple sclerosis (MS) have been rarely reported and suggest the possibility of an alternative diagnosis. The aim was to describe the clinical and demographic characteristics of MS patients who debuted with atypical symptoms and to estimate the sensitivity, specificity and positive predictive value (PPV) for MS diagnosis. A retrospective analysis of clinical records was performed. The following data were recorded: patients with MS diagnosis according to current diagnostic criteria at the time of diagnosis, type of symptom at the onset, time to second relapse, presence of oligoclonal bands (OCB) in cerebrospinal fluid (CSF) and radiological red flags on MRI. A descriptive and inferential analysis was performed using the chi square test, and sensitivity, specificity and PPV were calculated. Six hundred two patients were diagnosed with MS, of which 22 (3.65%) had an atypical clinical presentation. 54.5% were women. The mean age was 29 years (SD ± 11.7). The most common atypical symptom was peripheral facial palsy (27%). The PPV for atypical onset was 6.14%; p < 0.001. Sensitivity and specificity of these symptoms to MS diagnosis were 3.65% and 19%, respectively. In our research, the presence of atypical symptoms at the onset of MS was very low. Other diseases must be excluded, taking into account their low sensitivity, specificity and PPV.

Upper Limb Dexterity in Patients with Multiple Sclerosis: An Important and Underrated Morbidity.

BACKGROUND: Scales to assess disability in multiple sclerosis (MS) rarely provide reliable data on actual global impairment. Upper limb dysfunction is usually overlooked, which has a negative effect on patient well-being. We sought to analyze associations among upper limb dexterity, lower limb speed, and Expanded Disability Status Scale (EDSS) score; the difference in upper limb dexterity between patients with EDSS scores less than 5 and 5 or greater; and the associations that upper limb dexterity, lower limb speed, and EDSS score have with health-related quality of life measurements and depression. METHODS: A total of 140 adults with MS were evaluated using the Nine-Hole Peg Test, Timed 25-Foot Walk test, EDSS, Multiple Sclerosis International Quality of Life (MusiQoL) questionnaire, and Beck Depression Inventory. Thorough descriptive-analytical research was conducted using the Spearman correlation, multiple linear regression, and structural equation modeling. RESULTS: Upper limb dexterity was more closely related to EDSS score than lower limb speed (r = 0.43 vs 0.29, R 2 = 0.38) and was greatest in patients with EDSS scores less than 5 (P < .01). Moreover, upper limb dexterity was negatively associated with EDSS score and the MusiQoL questionnaire (rS = -0.557 to -0.321, P < .05). The correlation that depression has with upper limb dexterity loss was higher than the one it has with lower limb speed (0.098 vs 0.066, t > 1.96). CONCLUSIONS: Upper limb dexterity is associated with global disability, depression, and health-related quality of life. We advocate for the assessment of upper limb dexterity in patients with MS to adopt a better approach to their functional impairment.

Brain Function Assessment of Patients with Multiple Sclerosis in the Expanded Disability Status Scale: A Proposal for Modification.

BACKGROUND: There is no consensus regarding assessment of the brain function functional system (FS) of the Expanded Disability Status Scale (EDSS) in patients with multiple sclerosis (MS). We sought to describe brain function FS assessment criteria used by Argentinian neurologists and, based on the results, propose redefined brain function FS criteria. METHODS: A structured survey was conducted of 113 Argentinian neurologists. Considering the survey results, we decided to redefine the brain function FS scoring using the Brief International Cognitive Assessment for MS (BICAMS) battery. For 120 adult patients with MS we calculated the EDSS score without brain function FS (basal EDSS) and compared it with the EDSS score after adding the modified brain function FS (modified EDSS). RESULTS: Of the 93 neurologists analyzed, 14% reported that they did not assess brain function FS, 35% reported that they assessed it through a nonstructured interview, and the remainder used other tools. Significant differences were found in EDSS scores before and after the inclusion of BICAMS (P < .001). Redefining the brain function FS, 15% of patients modified their basal EDSS score, as did 20% of those with a score of 4.0 or less. CONCLUSIONS: The survey results show the importance of unifying the brain function FS scoring criteria in calculating the EDSS score. While allowing more consistent brain function FS scoring, including the modified brain function FS led to a change in EDSS score in many patients, particularly in the lower range of EDSS scores. Considering the relevance of the EDSS for monitoring patients with MS and for decision making, it is imperative to further validate the modified brain function FS scoring.

Safety of Positive Pressure Extubation Technique.

BACKGROUND: Laboratory studies suggest applying positive pressure without endotracheal suction during cuff deflation and extubation. Although some studies reported better physiological outcomes (e.g. arterial blood gases) with this technique, the safety of positive pressure extubation technique has not been well studied. The aim of this study was to determine the safety of the positive-pressure extubation technique compared with the traditional extubation technique in terms of incidence of complications. METHODS: Adult subjects who were critically ill and on invasive mechanical ventilation who met extubation criteria were included. The subjects were randomly assigned to positive-pressure extubation (n = 120) or to traditional extubation (n = 120). Sequential tests for noninferiority and, when appropriate, for superiority were performed. Positive pressure was considered noninferior if the upper limit of the CI for the absolute risk difference did not exceed a threshold of 15% in favor of the traditional group, both in per protocol and intention-to-treat analyses. A P value of <.05 was considered significant. RESULTS: A total of 236 subjects were included in the primary analysis (per protocol) (119 in the positive-pressure group and 117 in the traditional group). The incidence of overall major and minor complications, pneumonia, extubation failure, and reintubation was lower in the positive-pressure group than in the traditional group, with statistical significance for noninferiority both in the per protocol (P < .001) and intention-to-treat (P < .001) analyses. The lower incidence of major complications found in the positive-pressure group reached statistical significance for the superiority comparison, both in per protocol (P = .03) and intention-to-treat (P = .049) analyses. No statistically significant differences were found in the superiority comparison for overall complications, minor complications, pneumonia, extubation failure, and reintubation. CONCLUSIONS: Positive pressure was safe and noninferior to traditional extubation methods. Furthermore, positive pressure has shown to be superior in terms of a lower incidence of major complications. (ClinicalTrials.gov registration NCT03174509.).

La predicción de rendimiento académico y deserción en estudiantes universitarios / Predicting academic performance and attrition in undergraduate students

The purpose of this study is to analyze whether educational aptitudes can predict academic performance and attrition. To measure educational aptitudes, the Differential Aptitude Test (DAT) was applied to a nonrandom sample of 1530 first year undergraduate students of a private university in Argentina. For the analysis, multiple and logistic regression models were used. The results showed that DAT scores can predict academic performance, but there is a moderate to low relationship between these scores and dropout rates. To summarize, this study is a first step to predict studentsÆ academic success, in order to save resources and prevent frustration...

El propósito de este estudio es analizar si las aptitudes educativas pueden predecir el rendimiento académico y la deserción. Para medir las aptitudes educativas se aplicó el Test de Aptitudes Diferenciales (Differential Aptitude Test û DAT) a una muestra no probabilística de 1530 estudiantes de primer año de grado de una universidad privada de la Argentina. Para el análisis se utilizaron modelos de regresión múltiple y logística. Los resultados muestran que el DAT puede predecir el rendimiento académico, mientras que la relación entre el DAT y la deserción es de moderada a baja. Este estudio es un primer paso para predecir el éxito académico de los estudiantes, con el objetivo de ahorrar recursos y evitar la frustración...

Eliminacion urinaria de ioduro en estudiantes universitarios de Buenos Aires / Urinary Iodine Excretion in University Students from Buenos Aires / Eliminação urinária de iodeto em estudantes universitários de Buenos Aires

La Ley Argentina 17.259 (promulgada en 1967), sobre el enriquecimiento con iodo de la sal de consumo humano, evidenció su eficiencia como profilaxis del bocio endémico. Sin embargo, el recrudecimiento de trastornos tiroideos se ha atribuido al incumplimiento de la legislación. Objetivo: Evaluar la eliminación urinaria de ioduro en un grupo de estudiantes de la Universidad de Buenos Aires, entre los años 2006 y 2011. Metodología: Se estudiaron 67 mujeres y 18 varones, cuyas características (promedio ± DE y rango) fueron, respectivamente: edad (años): 23,1 ± 2,4 (21 – 30) y 24,6 ± 4,4 (21 – 36); IMC (kg/m2): 21,5 ± 4,7 (17,4-34,1) y 22,8±1,9 (19,5-25.0). Se recolectaron muestras de orina de 12 hs determinando: ioduria (método cinético, modificado por Pino S, 1996) y creatinina (método de Jaffé). Los resultados se expresaron como ioduria (μg/L) y como iodo/creatinina (μg/g). Resultados: Los valores promedio ± DE (rango) fueron: mujeres y varones, respectivamente:iodo/creatinina(μg/g): 245 ± 268 (3 -1352); 106 ± 48 (43 - 235); ioduria (μg/L): 171 ± 97 (18 - 431) y 144 ± 57 (27 - 279). La adecuación según los valores de iodo/creatinina (μg/g) fue para mujeres y varones, respectivamente, de 18 % y 50%; la deficiencia moderada-severa: 11% y 6%; y los valores elevados de 71 % y 44 %. Según la ioduria (μg/L), la adecuación fue del 36% y 69%; la deficiencia del 30% y 19%; y los valores elevados y/o riesgo de efectos adversos: 35% y 22%, respectivamente en todos los casos. Conclusión: Estos resultados muestran la necesidad de controlar los niveles de iodación teniendo en cuenta el consumo de sal para evitar tanto la deficiencia como los efectos adversos del exceso, ampliando los estudios de estado nutricional respecto del iodo.

To evaluate urinary iodine excretion in a group of students attending Buenos Aires University, between years 2006 and 2011.Methods: the characteristics of the students were (mean± SD and range): females (n=67): age (ys), 23,1± 2.4 (21 –30); BMI (kg/m2): 21.5±4.7 (17.4–34.1); males (n=18): age(ys): 24.6±4.4 (21–36); BMI (kg/m2): 22.8±1.9 (19.5–25.0). Urinary samples were collected between 8 pm and 8 am;iodine (kinetic method modified by Pino S, 1996) and creatinine (Jaffé method) were determined. Results were expressed as iodine (μg/L) and iodine/creatinine ratio(μg/g).Results: mean ± SD and range were: iodine/creatinineratio (μg/g): females: 245±268 (3–1352); males: 106±48(43–235); iodine (μg/L): 171±97 (18–431) and 144±57(27–279). Distribution of the population according to the international criteria showed iodine/creatinine (μg/g) infemales and males, respectively: adequacy: 18 % and50%; deficiency: 11% and 6%; high values: 71 % and 44%. According to urinary iodine (μg/L): adequacy: 36%and 69%; deficiency 30% and 19%; high values or adverse effects risk: 35% y 22%.Conclusions: these results show a great variability in the iodine nutritional status in this group of healthy adults.Therefore, it would be advisable to control the iodine content of the commercial salts taking into account the Argentine legislation and the claims regarding there commendations of lowering salt consumption in orderto avoid iodine deficiency and the risk of adverse events.

A Lei Argentina 17.259 (promulgada em 1967), sobre o enriquecimento com iodo do sal de consumo humano,evidenciou sua eficiência como profilaxia do bócio endêmico. Objetivo: Avaliar a eliminação urinária de iodeto em um grupo de estudantes da Universidade de Buenos Aires,entre os anos 2006 e 2011. Metodologia: Foram estudados 67 mulheres e 18 homens, cujas características (em média ± DE e faixa) foram, respectivamente idade (anos): 23,1 ± 2,4 (21 – 30)e 24,6 ± 4,4 (21 – 36); IMC (kg/m2): 21,5 ± 4,7 (17,4-34,1) e 22,8±1,9 (19,5-25.0).Foram coletadas amostras de urina de 15h determinando: iodúria (método cinético,modificado por Pino S, 1996) e creatinina (método deJaffé). Os resultados foram expressos como iodúria(μg/L) e como iodo/creatinina (μg/g). Resultados: Os valores médios ± DE (faixa) foram: mulheres e homens, respectivamente: iodo/creatinina (μg/g): 245± 268 (3 -1352); 106 ± 48 (43 - 235); iodúria (μg/L): 171 ± 97 (18 - 431) e 144 ± 57 (27 – 279). A adequação segundo os valores de iodo/creatinina (μg/g) foi para mulheres e homens, respectivamente, de 18% e 50%; a deficiência moderada-severa: 11% e 6%; e os valores elevados de 71% e 44%. De acordo com a iodúria (μg/L), a adequação foi de 36% e 69%; a deficiência de 30% e 10%; e os valores elevados e/ou risco de efeitos adversos: 35% e 22%, respectivamente em todos os casos.Conclusão: Estes resultados mostram a necessidade de controlar os níveis de iodação tendo em conta o consumode sal para evitar tanto a deficiência quanto os efeitos adversos do excesso, ampliando os estudos de estado nutricional em relação ao iodo.

Rule-dependent anticipatory activity in prefrontal neurons.

The flexibility of the behavior of humans and other primates comes from the cognitive capability to use different behavioral modes depending on the contextual information. To investigate the neural mechanism of such a cognitive function, we trained monkeys to participate in a repeated category-outcome reversal. To perform the task efficiently, they had to explore and remember the relevant rule, i.e., which group of stimuli was associated with which outcome, and apply that rule to the visual cue in order to predict an outcome and select a response correctly. We recorded single-unit activity from the prefrontal cortex, including dorsolateral/ventrolateral prefrontal cortex and orbitofrontal cortex, and found that many neurons in these areas showed rule-dependent changes in activity during the trial and during the inter-trial-interval. The time period when a high proportion of neurons started to show rule-dependent activity was the precue period, and the typical activity pattern at that time was sustained and increasing firing towards the onset of the cue ("anticipatory" precue activity). The results indicate that the prefrontal cortex is involved in maintaining rule information in the short-term memory within and between trials and that the rule information is anticipatorily activated towards the onset of the task-relevant cue.

Efeito da suplementação de linhaça, óleo de canola e vitamina e na dieta sobre a oxidação dos ácidos graxos na gema dos ovos de galinhas poedeiras / Effect of supplementation of flaxseed, canola oil and vitamin e on diet in fatty acids oxidation of egg yolk laying hens

A presente pesquisa teve como objetivo estudar o efeito de fontes deácidos graxos poliinsaturados- óleo de canola e/ou semente de linhaça com diferentes concentrações de vitamina E suplementar sobre o teor de produtos de oxidação de ácidos graxos na gema de ovos de galinhas. Utilizou-se 288 galinhas da linhagem Babcock que receberam dietas com 6% de óleo de canola, 20% de semente de linhaça moída ou 3% de óleo de canola e 10% de semente de linhaça moída com teores de 0, 100 e 200 UI/kg de a-tocoferol, para análise estatística dos resultados empregou-se arranjo fatorial 3X3 em blocos casualizados.Os grupos que receberam óleo de canola tiveram menores concentrações de malonaldeído (menor oxidação) na gema dos ovos que aqueles alimentados com linhaça, em ovos crus sem armazenamento e nos cozidos após armazenamento. Os ovos crustiveram as menores concentrações de produtos de oxidação dos ácidos graxos. Os grupos de ovos cozidos, que receberam 100 e 200UI/kgde vitamina E na dieta, tiveram menores teores de malonaldeído na gema dos ovos que os grupos não suplementados.

To investigate the effect of dietary sources of polyunsaturated fattyacids - canola oil and flaxseed – with different vitamin E supplementation upon the fatty acids oxidation produtcts deposition into the eggs. 288 Babcock laying hens were used. Birds were fed diets containing 6% of canola oil, 20% of flaxseed or a combination of 3% of canola oil and 10% of flaxseed, enriched with 0,100 or 200 Ul of dl-a-tocopheril acetate, hens were randomly allocated and the experimental design was a 3X3 factorial arrangement. The inclusion of flaxseed into the diet increased the yolk polyun saturated fatty acids oxidation products, in crude and cooked stored eggs. The concentration of fatty acids oxidation products de crease in crude eggs in all sources of polyunsaturated fatty acids. The cooked eggs without a-tocopherol supplementation in the diet increase the concentration of oxidation products when compared with cooked eggs from diets with 100 or 200UI a-tocopherol in the diet.

Decreased frequency and proliferative response of invariant Valpha24Vbeta11 natural killer T (iNKT) cells in healthy elderly.

Invariant natural killer T (iNKT) cells represent a well-established T cell lineage characterised in humans by TCR consisting of an invariant alpha chain encoded by Valpha24-JalphaQ genes, paired preferentially with a Vbeta11 chain. iNKT cells also share some characteristics with NK cells, such as the expression of the NK-associated receptor CD161 in humans. The T cell immune response is the most dramatically affected by ageing, although age-associated alterations in the phenotype and function of other cells of the immune system have been demonstrated. Despite the importance of iNKT cells in the regulation of the immune response, there are a limited number of studies on the effect of ageing on peripheral blood iNKT cells. Thus, in this work we analyse the effect of ageing on peripheral blood Valpha24(+)Vbeta11(+) iNKT cells by studying their frequency, phenotype and proliferative function in elderly individuals fulfilling the SENIEUR criteria of healthy ageing compared with healthy young donors. Our results demonstrated a significant decrease of the percentage of Valpha24(+)Vbeta11(+) iNKT cells in elderly donors. No significant differences were found in the expression of CD27, CD28, CD45RO, CD45RA(bright), CD161, CD94 and NKG2D on iNKT cells from young and elderly individuals. Proliferation of Valpha24(+)Vbeta11(+) iNKT cells in response to alpha-GalCer and IL2 was analysed by calculating the cumulative population doubling (PD) after 14 days of culture. The PD levels were lower in the elderly indicating that Valpha24(+)Vbeta11(+) iNKT cells from healthy elderly subjects had an impaired proliferative capacity. These results indicate that ageing associates with a significant decline in the percentage and proliferative response of peripheral blood iNKT cells. Given the important immunoregulatory role of iNKT cells, these alterations in their number and function could contribute to the deleterious immune response in the elderly.

Influência da adição de fontes marinhas de carotenóides à dieta de galinhas poedeiras na pigmentação da gema do ovo / Influence of sea sources of carotenoids added to the diet of laying hens on the egg yolk pigmentation

A presente pesquisa foi realizada a fim de estudar os efeitos da suplementação de duas fontes marinhas de carotenóides em concentrações crescentes na dieta sobre a pigmentação da gema de ovos de galinhas poedeiras. O delineamento experimental foi inteiramente casualizado e utilizou 288 galinhas poedeiras com 32 semanas de idade distribuídas em 12 tratamentos, sendo cada unidade experimental constituída de 3 repetições de 8 aves. As concentrações empregadas de óleo de salmão (Salmo salar) foram de 0,80%; 1,20%; 1,60%; 2,00%; e 2,40% e de alga marinha (Schizochytrium sp) de 0,50%; 0,75%; 1,00%; 1,25%; 1,50%; e 1,75%. A dieta basal foi isocalórica e isoprotéica e constituída à base de milho e soja. Quanto à pigmentação da gema, os valores dos equivalentes em β-caroteno obtidos para as aves que receberam óleo de salmão na dieta variaram significativamente (P<0,05) de 27,04 μg/g a 45,96 μg/g de gema, respectivamente, para 0,80% e 2,40% deste óleo. Para as aves alimentadas com alga, as médias oscilaram de 33,04 μg/g a 72,66 μg/g gema para as dietas apresentando, respectivamente, de 0,50% a 1,75% de alga. O escore visual (leque colorimétrico Roche) das gemas mostrou diferenças significativas (P<0,05) entre as médias dos tratamentos que oscilaram de 4,75 (0,80% de óleo de salmão) a 8,17 (2,40% do mesmo óleo). Para as dietas enriquecidas com alga os valores observados foram de 5,92 a 11,58, respectivamente, para percentuais de 0,50% e 1,75% desta fonte alimentar. O parâmetro de qualidade do albúmen, medido em unidades Haugh, mostrou diferenças significativas (P<0,05) para as médias dos tratamentos em relação ao grupo controle. Os coeficientes de correlação e de determinação observados entre os percentuais de óleo de salmão ou de alga na dieta e os teores de equivalentes β-caroteno na gema (μg/g) evidenciaram a existência de linearidade significativa (P<0,05) entre estas variáveis.

This experiment was carried out to evaluate the effect of the utilization of two sources of marine carotenoids added to the diet on the egg yolk pigmentation of laying hens. A completely randomized design using 288 laying hens with 32 weeks of age assigned in 12 treatments, with 3 repetitions of 8 layers each was used. The hens were fed a corn soybean basal diet supplemented with 0.80%; 1.20%; 1.60%; 2.00%; 2.40% salmon oil (Salmo salar) or 0.50%; 0.75%; 1.00%; 1.25%; 1.50%; and 1.75 % of marine algae (Schizochytrium sp). The diets were isocaloric and isoproteic. The yolk values of β-carotene equivalents (μg/g egg yolk) for the laying hens fed salmon oil diet ranged significantly (P<0.05) from 27.04 μg/g to 45.96 μg/g, respectively, for 0.80% and 2.40% salmon oil. Laying hens fed marine algae showed β-carotene equivalent means ranging from 33.04 μg/g to 72.66 μg /g egg yolk, respectively, for 0.50% and 1.75% of marine algae diets. Visual score for the egg yolk pigmentation at the eighth week of experiment showed significance (P<0.05) among means ranging from 4.75 to 8.17 for 0.80% and 2.40% salmon oil diets, respectively. The yolk pigmentation measured by visual score (colorimetric fan) of eggs from hens fed diets enriched with marine algae ranged from 5.92 (0.50% algae) to 11.58 (1.75% algae). Haugh units were significantly (P<0.05) improved when marine algae was added to the basal diet. The significant (P<0.05) correlation and determination coefficients observed between the percentages of salmon oil or marine algae in the diet and the β-carotene equivalents found into the yolk (μg/g) showed a strong positive linearity between these variables.

Efeito da adição de ácidos graxos insaturados e de vitamina E à dieta de galinhas e seu reflexo na composição lipídica e incorporação de alfa-tocoferol na gema do ovo / Effect of dietary supplementation of unsaturated fatty acids and vitamin E upon yolk lipid composition and alpha- tocopherol incorportation into the egg yolk

Foram utilizadas poedeiras, da linhagem Babcock, alimentadas com dietas contendo 20 por cento de semente de linhaça, 6 por cento óleo de canola ou combinação entre eles (10 por cento de semente e 3 por cento de óleo), suplementadas com 0, 100 e 200 UI de vitamina E por quilo de ração. Analisaram-se os teores de gorduras saturadas, insaturadas e poliinsaturadas da gema, a incorporação de alfa-tocoferol, assim como o desempenho produtivo e a qualidade da casca dos ovos. Poedeiras alimentadas com dieta contendo 20 por cento de semente de linhaça mostraram significativa piora na conversão alimentar, redução no peso do ovo, na produção de ovos, na espessura e peso da casca do ovo. A inclusão de semente de linhaça na dieta aumentou a incorporação de ácidos graxos poliinsaturados e diminuiu a de ácidos graxos monosaturados na gema do ovo. A concentração de alfa-tocoferol na gema foi diretamente proporcional aos seus teores na ração (R²=0,9613). Os grupos alimentados com 6 por cento de óleo de canola obtiveram maiores concentrações de alfa-tocoferol na gema que os demais.

Long-term melatonin administration increases polyunsaturated fatty acid percentage in plasma lipids of hypercholesterolemic rats.

This study was designed to investigate the effect of melatonin on the fatty acid composition of plasma and tissue lipids. Melatonin administration to rats fed with a standard diet only increased long-chain n-6 polyunsaturated fatty acids (PUFA) in total plasma lipids and liver phospholipids but induced significant changes in hypercholesterolemic rats. In plasma, palmitoleic and oleic acids increased and n-6 and n-3 PUFA decreased in hypercholesterolemic rats; theses changes were reversed by melatonin administration. The analysis of lipid fractions revealed that only the cholesteryl ester fraction was affected by melatonin. Histological studies of the carotid artery intima revealed the appearance, in hypercholesterolemic rats, of fatty streaks produced by a mass of foam cells covered by the endothelium and by a thin layer of mononucleated cells. These changes were prevented by melatonin. We conclude that long-term melatonin administration modifies the fatty acid composition of rat plasma and liver lipids and ameliorates the arterial fatty infiltration induced by cholesterol.