Fast method for the determination of copper,manganese and iron in seafood samples

A slurry sampling flame atomic absorption spectrometric method is proposed for the determination of copper, manganese and iron in oysters (Crassostrea rhizophora), clams (Anomalocardia brasiliana) and mussels (Mytella guiyanensis; Perna perna). Optimization was carried out using univariate methodology involving the following variables: nature and concentration of the acid solution for slurry preparation, sonication time and sample mass. The optimized conditions were 80 mg of sample ground in a cryogenic mil, dilution using 1.0 mol L⁻¹ nitric /hydrochloric acid solution, sonication time of 30 min and a slurry volume of 10 mL. The calibration curves had been prepared using standards of copper, manganese and iron also in 1.0 mol L⁻¹ nitric/hydrochloric acid solution. This method allowed the determination of copper, manganese and iron by FAAS, with detection limits of 0.17, 0.09 and 0.46 μg g⁻¹, respectively. The precision, expressed as relative standard deviation (RSD), are 3.0%, 2.9% and 3.8% (n=10), for concentrations of copper, manganese and iron of 17, 22 and 719 μg g⁻¹, respectively. The accuracy of the method was confirmed by analysis of the certified oyster tissue (NIST 1566b). The proposed method was applied for the determination of copper, manganese and iron in samples of oyster, clams and mussels, collected in Ubatuba and Todos os Santos Bay, Brazil. The obtained concentrations varied between 17.1 and 143.9 μg g⁻¹, 17.9 and 29.7 μg g⁻¹ and 364 and 1388 μg g⁻¹, respectively, for copper, manganese and iron. These values agree well with other data reported in the literature. The results showed no significant differences (P>0.005) using the proposed method with those obtained after complete digestion and determination by inductively coupled plasma-optical emission spectroscopy (ICP-OES).     

Investigation of amino acids in wolfberry fruit (Lycium barbarum) by solid-phase extraction and liquid chromatography with precolumn derivatization

The aim of this work is to present a simple and sensitive reverse-phase liquid chromatography method for the determination and investigation of amino acids in wolfberry fruit (Lycium barbarum) after solid-phase extraction-derivatization. The method linearity, calculated for each amino acid, had a correlation coefficient higher than 0.9950, in concentrations ranged from 9.60 to 3.33 × 10³ μmol L⁻¹. The detection limits of amino acids were between 2.42 and 6.51 μmol L⁻¹. The calculated recoveries for amino acids in wolfberry fruit were from 87.3% to 97.1% and relative standard deviations were from 2.62% to 5.22%. The investigation illustrated that each tested wolfberry fruit contained at least 16 amino acids and the main amino acids were glutamic acid, aspartic acid, proline, alanine, serine, glycine, lysine, and tyrosine. The levels of amino acid in wolfberry fruit were varying from different areas.     

Cathodic adsorptive stripping voltammetric determination of rutin in soybean cultivars

A highly sensitive and selective cathodic adsorptive stripping voltammetric method for determination of rutin is presented. The method relies on the accumulation of a Cu(II)–rutin complex at a hanging mercury drop electrode (HMDE), followed by its reduction during a differential pulse voltammetric scan. The electrochemical behavior of the Cu(II)–rutin complex at HMDE was investigated by cyclic voltammetry. Results show that the electrode process is adsorption-controlled and gradually becomes less reversible at high scan rates where peak separation grows. Under the optimized conditions (phosphate buffer pH 6, ?1.000 V accumulation potential, 180 s accumulation time, 70 mV pulse amplitude, 50 mV s^?1 scan rate and 1.6 × 10^?6 M Cu(II) concentration), the reduction peak current (I_pc) of the Cu(II)–rutin complex is linear (I_pc (nA) = 10.070 + 1.9 × 10⁸ [Rutina]) to rutin concentration in the range from 2.0 × 10^?7 to 1.4 × 10^?6 M, with a correlation coefficient of 0.999. The detection and quantification limits obtained were 7.0 × 10^?9 M and 2.2 × 10^?8 M, respectively. The method was successfully applied to the determination of rutin in soybean cultivars, with recoveries of 94–105%.     

Short-term toxicity tests on the harpacticoid copepod Tisbe battagliai: Lethal and reproductive endpoints

Short-term bioassays based on lethal and reproductive responses of Tisbe battagliai were applied to determine responses of copepods to copper and LAS. Percentage of spawning females, fecundity (F), and total newborn production (N) for 48 and 72 h were calculated for both substances. It was observed percentage of spawning females was not affected by sublethal concentrations of both compounds. Following values were obtained: EC₅₀(N)-48 h of 670±30 μg LAS L^?1 and EC₅₀(F)-48 h of 670±30 μg LAS L^?1; and EC₅₀(N)-72 h of 44.5±1.8 μg Cu L^?1 and EC₅₀(F)-72 h of 30.8±1.1 μg Cu L^?1. Lethal effects of the two substance-types were also assessed, obtaining the LC₅₀-24 h of 1980±160 μg LAS L^?1; and LC₅₀-48 h of 83.1±10.5 μg Cu L^?1 for nauplii; and LC₅₀-72 h of 157±25 μg Cu L^?1, and LC₅₀-72 h of 2660±270 μg LAS L^?1 for adults. Fecundity and total newborn production are sensitive endpoints for determining effects of toxicants.     

Evaluation of biogenic amines in fish sauce by derivatization with 3,5-dinitrobenzoyl chloride and micellar liquid chromatography

A simple, selective and sensitive method to quantify the biogenic amines cadaverine, 2-phenylethylamine, histamine and spermidine has been developed. The analytes were derivatized with 3,5-dinitrobenzoyl chloride and separated by micellar liquid chromatography. This is a practical technique for the selective determination and quantification of biogenic amines in fish sauce. Optimization of chromatographic conditions was made by an interpretative model, and the separation conditions were: C18 column (125 mm × 4.6 mm, 5 μm particle size), UV detection set at 260 nm, and a mobile phase of 0.15 mol L^?1 sodium dodecyl sulfate (SDS), pH 7. Validation was performed following the United States Food and Drug Administration (FDA) guidelines using spiked samples. Under these conditions, validation parameters were: linearity (0.5–500 μg mL^?1, r² > 0.9990), limits of detection (in the 158–375 ng mL^?1 range); intra and inter-day precision (relative standard deviation < 3.2% and 4.2%) and accuracy (in the range of 88.6–103.7% and 94.2–101.5%), respectively, and variations were lower than 4%. The proposed method was successfully applied to the monitorization of biogenic amines formation in unsalted and salted fish sauce samples. The suggested methodology was found useful in routine analysis of biogenic amines in fish sauce.     

Determination of trace amounts of germanium in food and fruit by spectrophotometry with p-methybenzeneazosalicylflurone

A novel spectrophotometric method was developed for determination of germanium in food and fruit using p-methybenzeneazosalicylflurone as a new chromogenic reagent. Under optimum reaction conditions, the reagent reacts with germanium(IV) to form a red complex with a maximum absorption at 502 nm. The apparent molar coefficient of the complex was 2.0×10⁵ L mol⁻¹ cm⁻¹, and a linear absorbance was obtained for 0–7 μg of germanium in 10 mL solution. The reaction completed rapidly and the absorbance of the complex remains stable for at least 24 h at room temperature. The effect of various substances on the determination of germanium was investigated in succession. The results indicated that all studied co-existing substances can be tolerated in considerable amounts, e.g., 4000-fold molybdenum(VI) and tin(II) do not interfere with the determination of germanium; its selectivity is obviously better than other reagents in the literature. The detection limit, calculated using three times the standard error of estimate of the calibration graph, is 0.006 μg g⁻¹of germanium with the pre-concentration of germanium in digested solution using ferric hydroxide as the co-precipitator.     

Evolution and dispersal of St. Louis encephalitis virus in the Americas

Using a Bayesian coalescent approach on a dataset of 73 envelope gene sequences we estimated substitution rates and dates of divergence for St. Louis encephalitis virus (SLEV) in the Americas. We found significant rate heterogeneity among lineages, such that “relaxed” molecular clock models were much better supported than a strict molecular clock. The mean substitution rate estimated for all SLEV was 4.1 × 10^?4 substitutions/site/year (95% HPD 2.5–5.7)—higher than previous estimates that relied on the less well-suited strict clock. Mean substitution rates for individual lineages varied from 3.7 × 10^?4 to 7.2 × 10^?4 substitutions/site/year. For the first time we also assessed the magnitude and direction of viral gene flow within the Americas. The overall direction of gene flow during the period represented by the phylogeny is from South to North, and the region between 15°N and 30°N latitude appears to be the major source of virus for the rest of North America, which is consistent with migratory birds returning to their northern breeding grounds having acquired infection while wintering in the region of the Gulf of Mexico.     

Metal accumulation and toxicity measured by PAM—Chlorophyll fluorescence in seven species of marine macroalgae

The effects of five metals, copper (Cu), chromium (Cr), Zinc (Zn), cadmium (Cd) and lead (Pb), on photosynthetic activity, measured as pulse amplitude modulation (PAM) chlorophyll fluorescence yield, was monitored in seven species of green, red and brown macroalgae over a 14 d period. The 10 μmol l^?1 of Cr and Zn reduced chlorophyll fluorescence of all species by day 4, and 10 μmol l^?1 of Cu and Cd reduced the fluorescence of some species; however, fluorescence yields of all species were unaffected by 10 μmol l^?1 of Pb. Metals were generally accumulated in the order of Cu>Pb>Zn>Cr>Cd. Ulva intestinalis accumulated the highest amounts of all metals, and Cladophora rupestris the lowest. A relationship between internal metal concentration and fluorescence was not always evident as in some cases fluorescence was reduced at low metal contents. In the case of Zn, fluorescence was lowest in plants which contained lowest concentrations after 14 d-exposure, possibly because plants had died and Zn leached out of the algal cells. The relationship between internal metal concentration and fluorescence was algal species and metal-specific.     

Optimization of preconcentration procedure using magnetic nanoparticles for the determination of manganese in cereal samples

In the present study, we developed a magnetic nanoparticle adsorbent that uses iron oxide nanoparticles as the core and 1-(2-pyridylazo)-2-naphthol (PAN) as manganese ion exchange groups in cereal samples. This adsorbent was shown to be quick and efficient for the adsorption of manganese due to higher specific surface area, lower mass removal resistance and the absence of internal diffusion resistance. This method is simple and rapid for the preconcentration and determination of manganese in food samples by inductively coupled plasma optical emission spectrometry (ICP OES). The technical feasibility of magnetic nanoparticles for the removal of manganese was investigated under batch studies. It was based on (PAN)-modified magnetic nanoparticles. Four variables (pH of solution, amount of extractant (E), amount of nanoparticles (N) and time) were regarded as factors in the optimization. Results of the two-level fractional factorial design (2^4?1) based on an analysis of variance demonstrated that only the pH, amount of extractant (E) and amount of nanoparticles (N) were statistically significant. Optimal conditions for the extraction of manganese were obtained using Box–Behnken design. For optimum recovery of manganese, the variables pH of solution, amount of nanoparticles and amount of extractant values were 9.44, 3.46 mg and 3.91 mg, respectively. In the optimum experimental conditions, the limit of detection and enrichment factor of the proposed method were 0.1 μg L^?1 and 28, respectively. The precision as RSD was 3.6% for concentration of 50 μg L^?1. The accuracy of the proposed procedure was evaluated by analysis of certified reference material. The method was applied to the determination of manganese in barley, wheat and rice flour samples. The manganese content in the samples analyzed varied from 7.8 to 19.9 μg g^?1.     

A rapid and sensitive method for the determination of dibutyl phthalate in wine by flow-injection chemiluminescence analysis

A sensitive method for the determination of picogram level dibutyl phthalate (DBP) in wine by flow-injection chemiluminescence (FI–CL) analysis is presented for the first time, which was based on the quenching effect of DBP on the luminol–myoglobin (Mb) CL system. The decrement of CL intensity was linearly proportional to the logarithm of DBP concentration in the range of 0.1–100 pg mL⁻¹ with the detection limit of 0.03 pg mL⁻¹ (3σ). At a flow rate of 2.0 mL min⁻¹, a complete determination of DBP including sampling and washing could be accomplished in 0.5 min, giving the maximum sample throughput of 120 h⁻¹. The proposed method was successfully applied to the determination of DBP in wine, human serum and urine samples with the relative standard deviations (RSDs) of less than 3.0% (n = 5). The molecule docking results showed that DBP interacted with the amino acid residues near the heme moiety of Mb. The possible CL mechanism of luminol–Mb–DBP reaction should be that the binding of Mb with DBP forming a 1:1 complex (binding constant K = 1.55 × 10⁴ L mol⁻¹) led to the conformational change of Mb and resulted in the quenching of CL intensity.     

Modified cerium(IV)-based antioxidant capacity (CERAC) assay with selectivity over citric acid and simple sugars

A Ce(IV)-based reducing capacity (CERAC) assay was developed to measure the total antioxidant capacity (TAC) of foods, in which Ce(IV) would selectively oxidize antioxidant compounds but not citric acid and reducing sugars. The redox potential of the Ce(IV) oxidant was fine-tuned in 0.3 M H₂SO₄ + 0.7 M Na₂SO₄ aqueous medium for selective oxidation. In the classical Ce(IV)-based assay for which the name CERAC was proposed, the presence of citric acid (at 1.5 × 10^?5 M) caused approximately 25% reduction in Ce(IV) (at 2.0 × 10^?4 M) recovery, whereas in the present method, the presence of citric acid (at 1.0 × 10^?4 M) caused negligible error in the TAC measurement of quercetin. The trolox equivalent antioxidant capacity (TEAC) values in the order of quercetin > rutin > gallic acid > catechin > caffeic acid ≥ ferulic acid > naringenin ≥ naringin > trolox ≥ ascorbic acid were established with the proposed method and were found to be compatible with those found with other antioxidant assays. It is noteworthy that naringin and rutin were also hydrolyzed in the acidic medium of the method so as to exert their full antioxidant capacity not measured by other TAC assays. The proposed TAC assay with Ce(IV) is simple, low-cost, rapid, and can be easily applied in modestly equipped conventional laboratories.     

Particle quantification of influenza viruses by high performance liquid chromatography

The influenza virus continuously undergoes antigenic evolution requiring manufacturing, validation and release of new seasonal vaccine lots to match new circulating strains. Although current production processes are well established for manufacturing seasonal inactivated influenza vaccines, significant limitations have been underlined in the case of pandemic outbreaks. The World Health Organization called for a global pandemic influenza vaccine action plan including the development of new technologies. A rapid and reliable method for the quantification of influenza total particles is crucially needed to support the development, improvement and validation of novel influenza vaccine manufacturing platforms. This work presents the development of an ion exchange-high performance liquid chromatography method for the quantification of influenza virus particles. The method was developed using sucrose cushion purified influenza viruses A and B produced in HEK 293 suspension cell cultures. The virus was eluted in 1.5 M NaCl salt with 20 mM Tris–HCl and 0.01% Zwittergent at pH 8.0. It was detected by native fluorescence and the total analysis time was 13.5 min. A linear response range was established between 1 × 10⁹ and 1 × 10¹¹ virus particle per ml (VP/ml) with a correlation coefficient greater than 0.99. The limit of detection was between 2.07 × 10⁸ and 4.35 × 10⁹ whereas the limit of quantification was between 6.90 × 10⁸ and 1.45 × 10¹⁰ VP/ml, respectively. The coefficient of variation of the intra- and inter-day precision of the method was less than 5% and 10%. HPLC data compared well with results obtained by electron microscopy, HA assay and with a virus counter, and was used to monitor virus concentrations in the supernatant obtained directly from the cell culture production vessels. The HPLC influenza virus analytical method can potentially be suitable as an in-process monitoring tool to accelerate the development of processes for the manufacturing of influenza vaccines.     

Cloud point extraction preconcentration and spectrophotometric determination of copper in food and water samples using amino acid as the complexing agent

A new method for the determination of trace copper was developed by cloud point extraction preconcentration and spectrophotometry. In the proposed approach, amino acid (isoleucine) was used as the chelating agent, and Triton X-100 was selected as the surfactant. Some factors including pH of sample solution, concentration of the chelating agent and surfactant, and equilibration temperature and time, which affected the extraction efficiency of Cu and its subsequent determination, were studied and optimized. Under the optimum conditions, the calibration graph was linear in the range of 10–1000 μg L^?1, preconcentration of 25 mL sample gave an enhancement factor of 22 and a detection limit of 5 μg L^?1. The method was successfully applied to the determination of Cu in food and water samples.     

Levels and sources of volatile organic compounds including carbonyls in indoor air of homes of Puertollano,the most industrialized city in central Iberian Peninsula. Estimation of health risk

Twenty nine organic air pollutants including carbonyl compounds, alkanes, aromatic hydrocarbons and terpenes were measured in the indoor environment of different houses together with the corresponding outdoor measurements in Puertollano, the most industrialized city in central Iberian Peninsula. VOCs were sampled during 8 weeks using Radiello^® passive samplers, and a questionnaire on potential VOCs sources was filled out by the occupants. The results show that formaldehyde and hexanal was the most abundant VOCs measured in indoor air, with a median concentration of 55.5 and 46.4 μg m⁻³, respectively followed by butanal (29.1 μg m⁻³), acetone (28.4 μg m⁻³) and acetaldehyde (21.4 μg m⁻³). After carbonyls, n-dodecane (13.1 μg m⁻³) and terpenes (α-pinene, 13.4 μg m⁻³ and limonene, 13.4 μg m⁻³) were the compounds with higher median concentrations. The indoor/outdoor (I/O) ratios demonstrated that sources in the indoor environment are prevailing for most of the investigated VOCs especially for limonene, α-pinene, hexanal, formaldehyde, pentanal, acetaldehyde, o-xylene, n-dodecane and acetone with I/O ratio >6. Multiple linear regressions were applied to investigate the indoor VOC determinants and Spearman correlation coefficients were used to establish common sources between VOCs. Finally, the lifetime cancer risk associated to formaldehyde, acetaldehyde and benzene exposure was estimated and they varied from 7.8 × 10⁻⁵ to 4.1 × 10⁻⁴ for formaldehyde, from 8.6 × 10⁻⁶ to 3.5 × 10⁻⁵ for acetaldehyde and from 2.0 × 10⁻⁶ to 1.5 × 10⁻⁵ for benzene. For formaldehyde, the attributed risk in most sampled homes was two orders of magnitude higher than the one (10⁻⁶) proposed as acceptable by risk management bodies.     

Bayesian skyline plot inference of the Toscana virus epidemic: A decline in the effective number of infections over the last 30 years

Toscana virus (TosV), a sandfly fever virus, is one of the main causes of the aseptic meningitis that occurs during the summer in some Mediterranean regions, and whose epidemiology is largely unknown. We used a Bayesian Markov Chain Monte Carlo approach and a relaxed molecular clock to estimate the demographic history of the TosV infection in a series of isolates sampled between 1980 and 2003. The estimated mean evolutionary rate was 2.5 × 10^?4 substitutions per site per year (95% HPD: 0.31–5.44 × 10^?4 subs/site/year). Bayesian skyline plot revealed a sharp decline in the effective number of infections over the last 30 years. In conclusion, our data suggest that continuous and prolonged perturbations of vector/phlebovirus interactions due to the relatively recent climate changes may have contributed to gradually reducing the viral population in endemic areas.     

Voltammetric determination of vitamin B6 in food samples and dietary supplements

A simple and rapid voltammetric method based on the use of disposable screen-printed electrodes is proposed for the determination of vitamin B₆. The influence of the pH on the voltammetric response was analyzed. Estimation of the linear range (2.0 × 10⁻⁶/7.2 × 10⁻⁵ M), calibration function, limit of detection (1.5 × 10⁻⁶ M) and reproducibility was performed along with the determination of possible interferences from species present in real samples. The proposed analytical system was successfully applied for the determination of pyridoxine in multivitamin supplements, energy drinks and breakfast cereals by using the standard addition method.     

Physicochemical characterisation of French royal jelly: Comparison with commercial royal jellies and royal jellies produced through artificial bee-feeding

Cu(II)/neocuproine (2,9-dimethyl-1,10-phenanthroline) complexes were utilized for spectrophotometric determination of total polyphenol content in beers. This procedure is based on the reduction of Cu(II) by polyphenols in hydroethanolic medium (pH 7.0) in the presence of neocuproine, yielding Cu(I)/complexes with maximum absorption at 454 nm. The sensitivity of the proposed method was compared with the AOAC method using tannic and gallic acid as standards. The average apparent molar absorptivity, in L cm⁻¹ mol⁻¹, of tannic acid (3.50 ± 0.20) × 10⁵ and gallic acid (5.12 ± 0.21) × 10⁴, was twice as high for the proposed method. A lower limit of detection (LOD) (2.9 × 10⁻¹ mg L⁻¹) was found when tannic acid was used in the proposed method. Additionally, less interference from the most common additives in beers was noticed. Total content of polyphenols was analyzed in 17 Brazilian samples. Results ranged from 35.5 to 556 mg L⁻¹ of tannic acid, with higher values for recovery rates (45.4–118%, mean 85.0%) than for gallic acid. Although tannic acid is a mixture of polygalloyl glucoses, the total polyphenol content found in the samples suggests that tannic acid should be used as a standard. This is the first attempt to use this particular copper complex to quantify total polyphenol content in beer samples.     

Protective immunity against Megalocytivirus infection in rock bream (Oplegnathus fasciatus) following CpG ODN administration

Rock bream iridovirus (RBIV) disease in rock bream (Oplegnathus fasciatus) remains an unsolved problem in Korea aquaculture farms. CpG ODNs are known as immunostimulant, can improve the innate immune system of fish providing resistance to diseases. In this study, we evaluated the potential of CpG ODNs to induce anti-viral status protecting rock bream from different RBIV infection conditions. We found that, when administered into rock bream, CpG ODN 1668 induces better antiviral immune responses compared to other 5 CpG ODNs (2216, 1826, 2133, 2395 and 1720). All CpG ODN 1668 administered fish (1/5 µg) at 2 days before infection (1.1 × 10⁷) held at 26 °C died even though mortality was delayed from 8 days (1 µg) and 4 days (5 µg). Similarly, CpG ODN 1668 administered (5 µg) at 2 days before infection (1.2 × 10⁶) held at 23/20 °C had 100% mortality; the mortality was delayed from 9 days (23 °C) and 11 days (20 °C). Moreover, when CpG ODN 1668 administered (1/5/10 µg) at 2/4/7 days before infection or virus concentration was decreased to 1.1 × 10⁴ and held at 20 °C had mortality rates of 20/60/30% (2 days), 30/40/60% (4 days) and 60/60/20% (7 days), respectively, for the respective administration dose, through 100 dpi. To investigate the development of a protective immune response, survivors were re-infected with RBIV (1.1 × 10⁷) at 100 and 400 dpi, respectively. While 100% of the previously unexposed fish died, 100% of the previously infected fish survived. The high survival rate of fish following re-challenge with RBIV indicates that protective immunity was established in the surviving rock bream. Our results showed the possibility of developing preventive measures against RBIV using CpG ODN 1668 by reducing RBIV replication speed (i.e. water temperature of 20 °C and infection dose of 1.1 × 10⁴).     

Genotypically distinct strains of Leishmania major display diverse clinical and immunological patterns in BALB/c mice

Infection with Leishmania major species is endemic in many provinces of Iran. Isolates from four endemic areas located in north (Damghan), center (Kashan), west (Dehloran), and south (Shiraz) of country which showed major distinctive polymorphism by RAPD-PCR method were evaluated. Isolates were inoculated to different groups of BALB/c mice and their clinical and immunological status was compared. Lesion size, parasite burden and T cell phenotype in lymph node (LN), and cytokine secretion in the culture of LN mononuclear cells were determined. The results showed the lowest and highest lesion sizes in mice infected by Shiraz strain (3.02 ± 0.52 mm) and Kashan strain (5.20 ± 0.45), respectively, 8 weeks after inoculation. No significant difference was observed between other strains. The parasite burden was significantly lower in lymph node of mice infected with strain of Damghan (1.51 × 10⁷) than Kashan (3.60 × 10⁹) and Shiraz (7.08 × 10⁹) strains, 8 weeks post-infection. However, Dehloran strain showed intermediate load of viable parasites (1.51 × 10⁹) in LN, 8 weeks post-infection. High ratios of IFN-γ/IL-4 were shown in mice inoculated by strain of Dehloran (3.17) and Damghan (2.66), but not in mice infected by other strains, 8 weeks post-infection. The highest and lowest ratios of CD4⁺/CD8⁺ T cells were found in LN cells of mice infected with Kashan (1.82) and Dehloran (1.00) strains, respectively. Results indicate that the lowest and intermediate loads of parasites induced by Damghan and Dehloran strains along with higher ratio of IFN-γ/IL-4 produced by both strains in LN of inoculated mice suggest that these strains have the capacity to shift the immune responses to a predominant Th1 response after 8 weeks infection in BALB/c mice and might be the ideal strains for vaccine studies and development of candidate vaccine against leishmaniasis.     

High-protein diet promotes a moderate postpartum weight loss in a prospective cohort of Brazilian women

ObjectiveWhether a high-protein (HP) diet promotes body weight loss (BWL) when compared with a low-protein (LP) diet is still unclear. Therefore, we evaluated the effects of an HP diet on BWL during postpartum.MethodsA food-frequency questionnaire with 81 items was applied at 6 mo after delivery to evaluate the diet of 430 postpartum women aged 18–45 y. Body weight was measured approximately at 0.5, 2, 6, and 9 mo after delivery. Body weight loss was modeled by comparing an HP diet (≥1.2 g · kg^?1 · d^?1) with an LP diet (<1.2 g · kg^?1 · d^?1) using mixed-effects linear regression models adjusted for energy intake, percentage of body fat at baseline, stature, age, race, smoking, and schooling.ResultsUsual energy intake was higher in the HP than in the LP diet group (2623 versus 1791 kcal, P < 0.0001). Daily mean protein intakes were 1.54 ± 0.32 g · kg^?1 · d^?1 for the HP group and 0.83 ± 0.20 g · kg^?1 · d^?1 for the LP group. A multivariate model showed that women in the HP group lost 316 ± 0.062 g of body weight more per month (P < 0.01) when compared with the LP group.ConclusionA reported higher protein intake may improve moderate postpartum body weight loss. Further studies should evaluate the long-term consequences of an HP diet postpartum.