Ubiquinone deficiency drives reverse electron transport to disrupt hepatic metabolic homeostasis in obesity.

Mitochondrial reactive oxygen species (mROS) are central to physiology. While excess mROS production has been associated with several disease states, its precise sources, regulation, and mechanism of generation in vivo remain unknown, limiting translational efforts. Here we show that in obesity, hepatic ubiquinone (Q) synthesis is impaired, which raises the QH 2 /Q ratio, driving excessive mROS production via reverse electron transport (RET) from site I Q in complex I. Using multiple complementary genetic and pharmacological models in vivo we demonstrated that RET is critical for metabolic health. In patients with steatosis, the hepatic Q biosynthetic program is also suppressed, and the QH 2 /Q ratio positively correlates with disease severity. Our data identify a highly selective mechanism for pathological mROS production in obesity, which can be targeted to protect metabolic homeostasis.

Meglumine antimoniate was associated with a higher cure rate than liposomal amphotericin B in the treatment of American tegumentary leishmaniasis: A retrospective cohort study from a Leishmania braziliensis-endemic area.

Background: Pentavalent antimonials (PAs) are the primary therapeutic option for American tegumentary leishmaniasis (ATL). However, the use of these drugs is complicated by adverse events (AEs), resistance and contraindications. Alternative therapies relative effectiveness is not well established. Objective: This study compared the effectiveness of liposomal amphotericin B (LAB) with intravenous meglumine antimoniate (NMG) in the treatment of ATL. We also analysed and compared associated AEs and treatment interruption rates. Methods: This was a retrospective cohort study from Brazil. The potential risk factors for the primary outcome were age, sex, total cutaneous lesion area, presence of mucosal lesions, AEs and treatment interruption. The primary outcome was lesion healing within 6 months of treatment. AEs and treatment interruption were also analysed. Multiple analytic strategies were employed to evaluate the reliability of the results. Results: Before propensity score (PS) matching, patients in the LAB group were older and had a higher frequency of mucosal lesions. The NMG group had a higher cure rate than the LAB group (cure rate 88% versus 55% respectively) in the adjusted analysis (relative risk (RR)=1.55 95% CI: 1.19 - 2.02) and after PS matching (RR=1.63 95% CI: 1.20 - 2.21). NMG group had a higher AE rate (event rate 52% versus 44%) in the adjusted analysis (RR= 1.61, 95% CI: 1.06 - 2.43, p=0.02), but this result was not observed after PS matching (RR= 0.87, 95% CI: 0.49 -1.52, p= 0.61). Conclusions: We observed that the NMG group had a higher cure rate than the LAB group, with an equivocally higher EV rate in the adjusted analysis.

Interactions of temperature and dietary composition on juvenile European lobster (Homarus gammarus, L.) energy metabolism and performance.

Optimal rearing temperatures for European lobster Homarus gammarus in aquaculture differ from those prevalent in their aquatic ecosystems and acclimating juveniles to the prevailing temperatures before release may aid in the success of re-stocking programs. As the dietary nutritional composition is important for optimal performance of H. gammarus, in this study we aimed to investigate whether juvenile growth and energy metabolism responses to temperature variation could be modulated by the diet. Prior to the trial start, the juveniles were divided into two groups. One was maintained at 19 °C and the other gradually adapted to 13 °C. From this point and for a 24-day period, juveniles (~ 100 mg) within each temperature group were assigned one of two experimental diets: a carbohydrate-rich (HC) or a protein-rich (HP) extruded feed. Antarctic krill (AK) was used as a control diet within each temperature group. Feed intake, growth, glycogen, glucose, lactate, and protein concentrations of H. gammarus in each group were evaluated. Regardless the dietary treatment, feed intake, cephalothorax protein and glucose, and abdominal glycogen and glucose levels decreased at colder temperature. The effect of lower temperature on growth (SGR and moulting rate declines) and energy metabolism (reduction on cephalothorax glycogen and protein) was more severe in HC-fed lobsters. Results showed that the impact of lower temperature on juvenile H. gammarus can be modulated by diet highlighting the importance of designing optimized diets not only for growth and feed efficiency but also for resilience to environmental variation.

Replacement of Antarctic krill (Euphausia superba) by extruded feeds with different proximate compositions: effects on growth, nutritional condition and digestive capacity of juvenile European lobsters (Homarus gammarus, L.).

Extruded feeds are widely used for major aquatic animal production, particularly for finfish. However, the transition from fresh/frozen to extruded/pelleted feeds remains a major obstacle to progressing sustainable farming of European lobster (Homarus gammarus). The aim of the present study was to investigate the effects of using extruded feeds with different protein levels and lipid/carbohydrate ratios on growth, feed utilisation, nucleic acid derived indices (sRD) and digestive enzymatic activity of H. gammarus juveniles. Six extruded feeds were formulated to contain two protein levels (400 and 500 g/kg), with three lipid/carbohydrate ratios (LOW - 1:3; MEDium - 1:2; HIGH - 1:1). The extruded feeds were tested against Antarctic krill (Euphausia superba) used as control (CTRL). Overall, the CTRL and 500MED feed supported the highest growth and nutritional condition estimated by means of sRD, while the poorest results were observed for the 400HIGH and 400MED groups. The FCR was significantly lower in the CTRL than all extruded feeds, among which the most efficient, i.e., lower FCR, was the 500MED. The highest activity of trypsin and amylase in lobsters fed the 400MED and 400HIGH feeds points to the activation of a mechanism to maximise nutrients assimilation. The highest lipase activity observed for the 500LOW and 500MED groups indicates a higher capacity to metabolise and store lipids. Overall, the results suggest that the 500MED feed (500 g/kg protein, 237 g/kg carbohydrates and 119 g/kg lipids) is a suitable extruded feed candidate to replace Antarctic krill, commonly used to grow lobster juveniles.

Potential benefits and risks of omega-3 fatty acids supplementation to patients with COVID-19.

Studies have shown that infection, excessive coagulation, cytokine storm, leukopenia, lymphopenia, hypoxemia and oxidative stress have also been observed in critically ill Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) patients in addition to the onset symptoms. There are still no approved drugs or vaccines. Dietary supplements could possibly improve the patient's recovery. Omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), present an anti-inflammatory effect that could ameliorate some patients need for intensive care unit (ICU) admission. EPA and DHA replace arachidonic acid (ARA) in the phospholipid membranes. When oxidized by enzymes, EPA and DHA contribute to the synthesis of less inflammatory eicosanoids and specialized pro-resolving lipid mediators (SPMs), such as resolvins, maresins and protectins. This reduces inflammation. In contrast, some studies have reported that EPA and DHA can make cell membranes more susceptible to non-enzymatic oxidation mediated by reactive oxygen species, leading to the formation of potentially toxic oxidation products and increasing the oxidative stress. Although the inflammatory resolution improved by EPA and DHA could contribute to the recovery of patients infected with SARS-CoV-2, Omega-3 fatty acids supplementation cannot be recommended before randomized and controlled trials are carried out.

Cellular target of isoquercetin from Passiflora ligularis Juss for glucose uptake in rat soleus muscle.

Quercetin 3-O-beta-d-glucopyranoside (isoquercetin) is one of the most frequent metabolites of the Passiflora ligularis Juss. The purpose of this study was to investigate the effect of the aqueous extract and ethanol fraction from P. ligularis Juss leaves on glycaemia and the mechanism of action of isoquercetin on glucose uptake. In the glucose tolerance test, the aqueous extract and ethanol fraction from P. ligularis Juss (125 mg/kg to 500 mg/kg o. g.) reduced glycaemia and increased the hepatic and muscular glycogen content. Phytochemical analysis evidenced the dominant presence of isoquercetin in the extract and fraction from leaves of P. ligularis Juss. Isoquercetin mediates the stimulatory effect on glucose uptake independent of insulin receptor activation but, involve PI3K, MAPK, MEK/ERK pathways and de novo protein synthesis to GLUT-4 translocation. Overall findings revealed that isoquercetin and aqueous extract and ethanol fraction of P. ligularis Juss leaves might be a promising functional food or medicine for the treatment or prevention of diabetes.

Astragalin augments basal calcium influx and insulin secretion in rat pancreatic islets.

Astragalin is a flavonol glycoside with several biological activities, including antidiabetic properties. The objective of this study was to investigate the effects of astragalin on glycaemia and insulin secretion, in vivo, and on calcium influx and insulin secretion in isolated rat pancreatic islets, ex vivo. Astragalin (1 and 10 mg / kg) was administered by oral gavage to fasted Wistar rats and serum glucose and plasma insulin were measured. Isolated pancreatic islets were used to measure basal insulin secretion and calcium influx. Astragalin (10 mg/ kg) decreased glycaemia and increased insulin secretion significantly at 15-180 min, respectively, in the glucose tolerance test. In isolated pancreatic cells, astragalin (100 µM) stimulated calcium influx through a mechanism involving ATP-dependent potassium channels, L-type voltage-dependent calcium channels, the sarcoendoplasmic reticulum calcium transport ATPase (SERCA), PKC and PKA. These findings highlight the dietary coadjuvant, astragalin, as a potential insulin secretagogue that may contribute to glucose homeostasis.

Um estudo de caso sobre a brincadeira do FORT-DA como indício de estruturação do sujeito / A case study on the game FORT-DA as evidence of subjective constitutionN / Un estudio de caso sobre el juego del FORT-DA como indicio de la estructuración del sujeto

Este artigo teve como objetivo discutir a constituição do sujeito a partir da brincadeira nomeada por Freud como Fort-da. Realizou-se estudo de caso de criança deficiente visual com base nos pressupostos da teoria psicanalítica, baseando-se em fragmento de fala durante brincadeiras simbólicas entre criança e terapeuta. Observou-se que tal fragmento de fala representou a possibilidade de emergência do sujeito sem o intuito de necessariamente designar diagnóstico estrutural à criança. Portanto, este estudo tornou-se relevante por discutir a possibilidade de estruturação subjetiva de tal criança à luz da articulação lacaniana entre Simbólico e Imaginário e o jogo do Fort-da de Freud.

This study aimed at discussing subject constitution from a game named by Freud as Fort-da. We used psychoanalytical theories to study the case of a visually impaired child, based on speech fragments while the child played symbolic games with their therapist. We observed that such speech fragment represented the possibility of subject's emergence without necessarily giving the child a structure diagnosis. Therefore, this study is relevant, since it discusses the possibility of a child's subjective constitution based on the lacanian articulation between Symbolic and Imaginary and on Freud's Fort-da.

El presente artículo discute la constitución del sujeto a partir de un juego llamado por Freud de Fort-da. Se realizó un estudio del caso de un niño deficiente visual con base en los presupuestos de la teoría psicoanalítica, utilizando un fragmento del habla durante los juegos simbólicos entre el niño y el terapeuta. Se observó que el fragmento del habla representó la posibilidad de emergencia del sujeto sin intención de necesariamente designar un diagnóstico estructural al niño. Por lo tanto, este estudio puede ser relevante para discutir la posibilidad de la estructuración subjetiva del niño a la luz de la articulación lacaniana entre lo Simbólico y lo Imaginario y del juego Fort-da de Freud.

Efeitos da suplementação de ácidos graxos poli-insaturados ω-3 em pacientes com doenças cardiovasculares / Supplementation effects of fatty acids polyunsaturated ω-3 in patients with cardiovascular diseases

Introdução: As doenças cardiovasculares (DCV) correspondem a um grupo de afecções que incluem a doença arterial coronariana, aterosclerose, hipertensão arterial sistêmica, doença cardíaca isquêmica, doença vascular periférica e insuficiência cardíaca. Os potenciais benefícios dos ácidos graxos poli-insaturados ω-3 (AGPI ω-3) são efeitos antitrombótico, anti-inflamatório e antiarrítmico; melhora do perfil cardíaco, da frequência cardíaca e da função endotelial, e redução da pressão arterial e do estresse oxidativo. Objetivo: Avaliar os potenciais benefícios da suplementação de AGPI ω-3 em pacientes com DCV. Método: Levantamento da literatura na base de dados eletrônica PubMed, compreendendo o período de maio de 2010 a maio de 2015. Nessa base de dados foram utilizados os descritores em inglês: "omega 3" combinado com "cardiovascular disease". Resultados: Foram analisados 19 artigos científicos, sendo que 42,1% dos estudos incluídos foram publicados no ano de 2011. Considerando o tipo de desenho do estudo, 57,9% dos artigos eram randomizados, multicêntricos, placebo-controlados e duplocego. Os resultados compilados nesse trabalho foram divergentes, visto que sete publicações não encontraram nenhuma melhoria nos desfechos analisados; entre as demais publicações, os resultados observados foram distintos. Benefícios foram encontrados para melhoria dos parâ- metros cardíacos, na coagulação sanguínea, concentração de triglicerídeos, concentração de leptina e adiponectina, melhoria de sintomas depressivos e redução da concentração plasmática de citocinas inflamatórias. Conclusão: A dificuldade de se observar os benefícios dos AGPI ω-3 se deve às melhorias do tratamento medicamentoso nas DCV.(AU)

Introduction: Cardiovascular diseases (CVD) represent a group of diseases including coronary artery disease, atherosclerosis, hypertension, ischemic heart disease, peripheral vascular disease and heart failure. The potential benefits of ω-3 polyunsaturated fatty acids (ω-3 PUFA) are antithrombotic, anti-inflammatory and antiarrhythmic effects; improvement of cardiac profile, heart rate and endothelial function; and lowering blood pressure and oxidative stress. Objective: To assess the potential benefits of ω-3 PUFA supplementation in patients with CVD. Methods: Literature review on electronic database PubMed, covering the period from 2010 May to 2015 May. In this database, the descriptors in English "omega 3" combined with "cardiovascular disease" were used. Results: Nineteen scientific papers were analyzed, and 42.1% of the included studies were published in 2011. Considering the type of study design, 57.9% of the papers were randomized, multicenter, placebo-controlled and double-blind. The results compiled in this study were divergent, once seven publications didn't find improvement in outcome measures; among the other publications the results obtained were distinct. Benefits have been found to improve cardiac parameters, blood coagulation, triglycerides concentration, leptin and adiponectin concentrations, improvement of depressive symptoms and decreased plasma concentration of inflammatory cytokines. Conclusion: The difficulty to observe the benefits of ω-3 PUFA is due to the improvement of drug treatment in CVD.(AU)

Anti-Mycobacterium tuberculosis Activity of Calophyllum brasiliense Extracts Obtained by Supercritical Fluid Extraction and Conventional Techniques.

The conventional techniques used to extract natural products have many disadvantages, and alternative methods have been used, such as supercritical fluid extraction (SFE-CO2). We compared the anti-Mycobacterium tuberculosis activity and cytotoxicity of extracts and major pure compounds were obtained from the leaves of Calophyllum brasiliense by SFE-CO2, maceration and Soxhlet. Anti-M tuberculosis activity was evaluated by resazurin microtiter assay plate and cytotoxicity assay was performed using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The (-) mammea A/BB, (-) mammea B/BB, mammea B/BB cyclo D, ponnalide, mammea A/BA cyclo D, and amentoflavone were identified as the majority compounds. SFE-CO2, especially at 313 K and 10.92 MPa showed better yield for (-) mammea A/BB. Anti-M. tuberculosis activity (62.5 µg/mL) and cytotoxicity (Selectivity Index = 0.320-0.576) were similar for the three extracts. Mammea B/BB cyclo D had a minimum inhibitory concentration (MIC) of 125 µg/mL, and ponnalide and mammea A/BA cyclo D had MICs > 250 µg/mL. The pure compounds isolated showed low Selectivity Index (< 0.09). SFE-CO2 may be more promising than conventional methods for the extraction of compound (-) mammea A/BB, which presented the best anti-M. tuberculosis activity in our previous study. This is important for current industrial requirements to obtain extracts from medicinal plants using clean technologies.

Identification of a selenium-dependent glutathione peroxidase in the blood-sucking insect Rhodnius prolixus.

The selenium-dependent glutathione peroxidase (SeGPx) is a well-studied enzyme that detoxifies organic and hydrogen peroxides and provides cells or extracellular fluids with a key antioxidant function. The presence of a SeGPx has not been unequivocally demonstrated in insects. In the present work, we identified the gene and studied the function of a Rhodnius prolixus SeGPx (RpSeGPx). The RpSeGPx mRNA presents the UGA codon that encodes the active site selenocysteine (Sec) and a corresponding Sec insertion sequence (SECIS) in the 3' UTR region. The encoded protein includes a signal peptide, which is consistent with the high levels of GPx enzymatic activity in the insect's hemolymph, and clusters phylogenetically with the extracellular mammalian GPx03. This result contrasts with all other known insect GPxs, which use a cysteine residue instead of Sec and cluster with the mammalian phospholipid hydroperoxide GPx04. RpSeGPx is widely expressed in insect organs, with higher expression levels in the fat body. RNA interference (RNAi) was used to reduce RpSeGPx gene expression and GPx activity in the hemolymph. Adult females were apparently unaffected by RpSeGPx RNAi, whereas first instar nymphs showed a three-day delay in ecdysis. Silencing of RpSeGPx did not alter the gene expression of the antioxidant enzymes catalase, xanthine dehydrogenase and a cysteine-GPx, but it reduced the levels of the dual oxidase and NADPH oxidase 5 transcripts that encode for enzymes releasing extracellular hydrogen peroxide/superoxide. Collectively, our data suggest that RpSeGPx functions in the regulation of extracellular (hemolymph) redox homeostasis of R. prolixus.

Dependence of brown adipose tissue function on CD36-mediated coenzyme Q uptake.

Brown adipose tissue (BAT) possesses the inherent ability to dissipate metabolic energy as heat through uncoupled mitochondrial respiration. An essential component of the mitochondrial electron transport chain is coenzyme Q (CoQ). While cells synthesize CoQ mostly endogenously, exogenous supplementation with CoQ has been successful as a therapy for patients with CoQ deficiency. However, which tissues depend on exogenous CoQ uptake as well as the mechanism by which CoQ is taken up by cells and the role of this process in BAT function are not well understood. Here, we report that the scavenger receptor CD36 drives the uptake of CoQ by BAT and is required for normal BAT function. BAT from mice lacking CD36 displays CoQ deficiency, impaired CoQ uptake, hypertrophy, altered lipid metabolism, mitochondrial dysfunction, and defective nonshivering thermogenesis. Together, these data reveal an important new role for the systemic transport of CoQ to BAT and its function in thermogenesis.

Effect of acute administration of L-tyrosine on oxidative stress parameters in brain of young rats.

Tyrosinemia type II, also known as Richner-Hanhart syndrome, is an autosomal recessive inborn error of metabolism caused by a deficiency of hepatic cytosolic tyrosine aminotransferase, and is associated with neurologic and development difficulties in numerous patients. Considering that the mechanisms underlying the neurological dysfunction in hypertyrosinemic patients are poorly known and that studies demonstrated that high concentrations of tyrosine provoke oxidative stress in vitro and in vivo in the cerebral cortex of rats, in the present study we investigate the oxidative stress parameters (enzymatic antioxidant defenses, thiobarbituric acid-reactive substances and protein carbonyl content) in cerebellum, hippocampus and striatum of 30-old-day rats after acute administration of L-tyrosine. Our results demonstrated that the acute administration of L-tyrosine increased the thiobarbituric acid reactive species levels in hippocampus and the carbonyl levels in cerebellum, hippocampus and striatum. In addition, acute administration of L-tyrosine significantly decreased superoxide dismutase activity in cerebellum, hippocampus and striatum, while catalase was increased in striatum. In conclusion, the oxidative stress may contribute, along with other mechanisms, to the neurological dysfunction characteristic of hypertyrosinemia and the administration of antioxidants may be considered as a potential adjuvant therapy for tyrosinemia, especially type II.

Comparing conventional and supercritical extraction of (-)-mammea A/BB and the antioxidant activity of Calophyllum brasiliense extracts.

Calophyllum brasiliense is a rich source of bioactive coumarins, xanthones and biflavonoids. The aim of the study was to compare the phenol contents and the antioxidant activity of C. brasiliense extracts obtained by conventional and supercritical fluid extraction (SFE) methods, as well as the quantification of crude extracts and (-)-mammea A/BB yields. Dichloromethane and hexane were used as solvents for the conventional extractions and SFE was developed using supercritical CO2; the kinetic curves were modeled using a second-order empirical model. The dichloromethane extract presented the best total yield, although it showed the lowest content of (-)-mammea A/BB. The concentration of the coumarin was considerably higher in extracts obtained by the supercritical fluid method and a higher antioxidant activity was assigned to extracts obtained by this technique. Concerning the total phenolic contents, both the dichloro-methane and the supercritical extractions produced satisfactory amounts. The SFE method proved to be more promising than conventional methods.

1α,25-dihydroxyvitamin D(3) mechanism of action: modulation of L-type calcium channels leading to calcium uptake and intermediate filament phosphorylation in cerebral cortex of young rats.

The involvement of calcium-mediated signaling pathways in the mechanism of action of 1α,25-dihydroxyvitamin D(3) (1,25D) is currently demonstrated. In this study we found that 1,25D induces nongenomic effects mediated by membrane vitamin D receptor (VDRm) by modulating intermediate filament (IF) phosphorylation and calcium uptake through L-type voltage-dependent calcium channels (L-VDCC) in cerebral cortex of 10 day-old rats. Results showed that the mechanism of action of 1,25D involves intra- and extracellular calcium levels, as well as the modulation of chloride and potassium channels. The effects of L-VDCCs on membrane voltage occur over a broad potential range and could involve depolarizing or hyperpolarizing coupling modes, supporting a cross-talk among Ca(2+) uptake and potassium and chloride channels. Also, the Na(+)/K(+)-ATPase inactivation by ouabain mimicked the 1,25D action on (45)Ca(2+) uptake. The Na(+)/K(+)-ATPase inhibition observed herein might lead to intracellular Na(+) accumulation with subsequent L-VDCC opening and consequently increased (45)Ca(2+) (calcium, isotope of mass 45) uptake. Moreover, the 1,25D effect is dependent on the activation of the following protein kinases: cAMP-dependent protein kinase (PKA), Ca(2+)/calmodulin-dependent protein kinase (PKCaMII), phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase p38 (p38(MAPK)). The modulation of calcium entry into neural cells by the 1,25D we are highlighting, might take a role in the regulation of a plethora of intracellular processes. Considering that vitamin D deficiency can lead to brain illness, 1,25D may be a possible candidate to be used, at least as an adjuvant, in the pharmacological therapy of neuropathological conditions.

Ajuste de modelos de platô de resposta via regressão isotônica / Response plateau models fitting via isotonic regression

Dentro do contexto nutricional, a suplementação de microminerais em rações para aves frequentemente é feita em quantidades superiores às exigidas na tentativa de assegurar o bom desempenho dos animais. Os experimentos do tipo dose resposta são muito comuns na determinação de níveis ótimos dos nutrientes na ração e contemplam a utilização de modelos de regressão para atingir tal objetivo. Porém, na análise de regressão usual, geralmente, não se usa uma informação a priori sobre uma possível relação de ordem na variável resposta. A regressão isotônica é um método de estimação por mínimos quadrados que gera estimativas que satisfazem a mesma ordenação dos dados. Na teoria da regressão isotônica, essa informação é utilizada de forma essencial e espera-se que a eficiência do ajuste seja aumentada quando se faz uso dela. Diante do exposto, o presente trabalho tem como objetivo utilizar uma metodologia de regressão isotônica, como uma forma alternativa para analisar dados de deposição de zinco (Zn) na tíbia de aves machos da linhagem Hubbard. No estudo, foram considerados os modelos de platô de resposta polinomial quadrático e não linear exponencial. Além desses modelos, também foi proposto o ajuste de um modelo logarítmico para os dados e a eficiência da metodologia foi avaliada por meio de um estudo de simulação Monte Carlo, considerando diferentes cenários para os valores paramétricos. A isotonização dos dados propiciou uma melhora em todos os avaliadores de qualidade de ajuste considerados no trabalho. Dentre os modelos utilizados, o logarítmico apresentou estimativas dos parâmetros mais coerentes com os valores relatados na literatura, para os dados de deposição de Zn na tíbia de aves machos.

Within the nutritional context, the supplementation of microminerals in bird food is often made in quantities exceeding those required in the attempt to ensure the proper performance of the animals. The experiments of type dosage x response are very common in the determination of levels of nutrients in optimal food balance and include the use of regression models to achieve this objective. Nevertheless, the regression analysis routine, generally, uses a priori information about a possible relationship between the response variable. The isotonic regression is a method of estimation by least squares that generates estimates which preserves data ordering. In the theory of isotonic regression this information is essential and it is expected to increase fitting efficiency. The objective of this work was to use an isotonic regression methodology, as an alternative way of analyzing data of Zn deposition in tibia of male birds of Hubbard lineage. We considered the models of plateau response of polynomial quadratic and linear exponential forms. In addition to these models, we also proposed the fitting of a logarithmic model to the data and the efficiency of the methodology was evaluated by Monte Carlo simulations, considering different scenarios for the parametric values. The isotonization of the data yielded an improvement in all the fitting quality parameters evaluated. Among the models used, the logarithmic presented estimates of the parameters more consistent with the values reported in literature.

[Relationship between lead levels in colostrum, dietary intake, and socioeconomic characteristics of puerperal women in Goiânia, Brazil]. / Relação entre níveis de chumbo no colostro, consumo alimentar e características socioeconômicas de puérperas em Goiânia, Brasil.

OBJECTIVE: To estimate the levels of lead in human colostrum and investigate whether they are correlated with dietary intake and socioeconomic factors in puerperal women. METHOD: This cross-sectional study was carried out with 80 puerperal women from a maternity hospital in Goiânia, Brazil. Data were collected between July and December 2008. A questionnaire was used to collect socioeconomic and lifestyle information. A dietary intake frequency questionnaire was also applied. After that, colostrum samples were collected and analyzed using flame atomic absorption spectrometry to quantify lead levels. The correlation between lead levels, socioeconomic variables, and dietary intake was calculated. RESULTS: The mean concentration of lead in colostrum samples was 6.88 µg/L, and the median concentration was 4.65 µg/L. There was no association between socioeconomic aspects and lead levels. The intake of saturated fatty acids, eggs, pork meats, chicken, and chicken products (r = -0.26 and P = 0.020) was inversely correlated with the levels of lead in human colostrum, whereas the intake of squash (r = 0.26; P = 0.019) and eggplant (r = 0.27; P = 0.015) was positively correlated with the levels of lead. The correlation observed for cooked squash, eggs, pork and chicken meats, and chicken products was maintained after logistic regression adjustment. CONCLUSIONS: The presence of lead was detected in human colostrum in this sample, probably as a result of dietary exposure. In addition to a correlation between presence of lead and dietary intake, the present findings suggest that specific nutrients may result in increased or decreased levels of lead, without a direct relationship with socioeconomic factors.

Relação entre níveis de chumbo no colostro, consumo alimentar e características socioeconômicas de puérperas em Goiânia, Brasil / Relationship between lead levels in colostrum, dietary intake, and socioeconomic characteristics of puerperal women in Goiânia, Brazil

OBJETIVO: Estimar a concentração de chumbo em colostro humano e verificar a existência de relação entre esse dado, consumo alimentar e fatores socioeconômicos das puérperas. MÉTODOS: Estudo transversal com 80 puérperas de uma maternidade de Goiânia, Brasil, realizado de julho a dezembro de 2008. Aplicou-se um questionário socioeconômico e de estilo de vida, além do questionário de frequência de consumo alimentar. Posteriormente, foram coletadas amostras de colostro, analisadas por espectrometria de absorção atômica por chama para quantificar o chumbo. Calculou-se a correlação entre o teor de chumbo, as variáveis socioeconômicas e o consumo alimentar. RESULTADOS: A média da concentração de chumbo foi 6,88 μg/L, e a mediana foi 4,65 μg/L. Os aspectos socioeconômicos não apresentaram associação significativa com o teor de chumbo. A ingestão de ácidos graxos saturados, ovos, carnes suínas, frango e derivados (todos com valores de r = -0,26 e P = 0,020) correlacionou-se inversamente ao teor chumbo do colostro humano, ao passo que a ingestão de abóbora (r = 0,26 e P = 0,019) e berinjela (r = 0,27 e P = 0,015) correlacionou-se proporcionalmente ao valor obtido. A correlação entre abóbora cozida, ovos, carnes suínas, de frango e derivados foi mantida após ajuste na regressão logística. CONCLUSÕES: Foi detectada presença de chumbo no colostro materno, possivelmente como resultado da exposição dietética das puérperas deste estudo. Além da correlação entre presença de chumbo e consumo alimentar, os resultados sugerem que a ingestão de nutrientes específicos pode propiciar maior ou menor concentração desse contaminante, sem relação direta com fatores socioeconômicos.

OBJECTIVE: To estimate the levels of lead in human colostrum and investigate whether they are correlated with dietary intake and socioeconomic factors in puerperal women. METHOD: This cross-sectional study was carried out with 80 puerperal women from a maternity hospital in Goiânia, Brazil. Data were collected between July and December 2008. A questionnaire was used to collect socioeconomic and lifestyle information. A dietary intake frequency questionnaire was also applied. After that, colostrum samples were collected and analyzed using flame atomic absorption spectrometry to quantify lead levels. The correlation between lead levels, socioeconomic variables, and dietary intake was calculated. RESULTS: The mean concentration of lead in colostrum samples was 6.88 μg/L, and the median concentration was 4.65 μg/L. There was no association between socioeconomic aspects and lead levels. The intake of saturated fatty acids, eggs, pork meats, chicken, and chicken products (r = -0.26 and P = 0.020) was inversely correlated with the levels of lead in human colostrum, whereas the intake of squash (r = 0.26; P = 0.019) and eggplant (r = 0.27; P = 0.015) was positively correlated with the levels of lead. The correlation observed for cooked squash, eggs, pork and chicken meats, and chicken products was maintained after logistic regression adjustment. CONCLUSIONS: The presence of lead was detected in human colostrum in this sample, probably as a result of dietary exposure. In addition to a correlation between presence of lead and dietary intake, the present findings suggest that specific nutrients may result in increased or decreased levels of lead, without a direct relationship with socioeconomic factors.

[Cadmium in human milk: concentration and relation with the lifestyle of women in the puerperium period]. / Cádmio no leite materno: concentração e relação com o estilo de vida da puérpera.

PURPOSE: To relate the cadmium concentration of colostrum with the lifestyle of women in the puerperium period. METHODS: A cross-sectional study was conducted in Goiânia, Goiás (Mid-western Region of Brazil). Eighty women, according to inclusion criteria, were interviewed about their socioeconomic characteristics and lifestyle. They answered a questionnaire about food frequency consumption (FFQ). The colostrum samples collected were analyzed by flame atomic absorption spectrometry to quantify cadmium levels. For statistical analysis, central tendency measures were obtained, and the Mann-Whitney and Kruskal-Wallis tests were performed, as well as correlation and regression tests. RESULTS: The average cadmium concentration was 2.3 µg/L and the median was 0.9 µg/L. Variables such as age and parity showed a nonsignificant positive correlation with cadmium. Smoking habit was not significantly associated with cadmium. CONCLUSIONS: Postpartum food intake influences the level of cadmium in colostrum, especially vegetables such as cereals.