Preparación, caracterización de recubrimientos de Lactobacillus plantarum con quitosano y su aplicación en la conservación de la calidad poscosecha de litchi y rambután

Los frutos no climatéricos de la familia de las sapindáceas, como el litchi y el rambután, ven afectada su comercialización por problemas de pérdida de peso y oscurecimiento del epicarpio, debido a la degradación de los pigmentos rojos característicos. El pardeamiento es un proceso bioquímico favorecido por el cambio de pH y la deshidratación. Por este motivo se han implementado tratamientos químicos de conservación del color que no obstante su efectividad no garantizan inocuidad de los frutos al ser un riesgo para la salud humana. Por tanto en el presente estudio se propone el empleo de recubrimientos comestibles y biodegradables que no afectan al consumidor. El objetivo del trabajo fue elaborar recubrimientos con polímeros naturales y bacterias lácticas que mantuvieran el color rojo de los epicarpios de los frutos de rambután y litchi. Las aplicaciones en litchi se realizaron tanto en laboratorio como en campo, éstos últimos fueron llevados a cabo en las fincas de productores cooperantes en la Región del Papaloapan en el estado de Oaxaca. Las características funcionales de los componentes de los recubrimientos empleados fueron aprovechados tales como su actividad antimicrobiana, biodegradabilidad y biocompatibilidad del quitosano; nematicida y fungistática del aceite de neem (N); así como la producción de ácido láctico in situ de Lactobacillus plantarum (BAL). Se elaboraron diversas formulaciones con estos componentes variando las concentraciones de 5g/L y 10 g/L, asimismo se modificó químicamente el quitosano nativo mediante funcionalización con hidroxipropilmetilcelulosa (Q-g-HPMC) quitosano biológico-químico (Q) y comercial (QC) y BAL las cuales se probaron libres en combinación con quitosano B-Q, en coacervados (CoBAL) y en complejos solubles(QPBAL), los tratamientos de CoBAL formulados con quitosano y pectina en relación 1:2 y QPBAL en relación 1:1 , debido a las propiedades del quitosano y la pectina, el primero de carácter catiónico y el segundo aniónico. Los tratamientos en emulsión, disminuyeron la pérdida fisiológica de peso (PFP) de los frutos, sin embargo las demás variables de calidad medidas como las concentraciones de antocianinas totales, cianidina-3- rutinósido y catequina fueron bajas, lo cual pudo deberse a la oxidación del aceite vegetal utilizado en la preparación de las emulsiones. Se compararon los quitosanos Q y QC, siendo el primero el que presentó mejores resultados en la conservación de la calidad poscosecha de los frutos. El mejor tratamiento fue el que contenía a las BAL libres, seguida de COBAL y QPBAL. Los complejos solubles y coacervados obtuvieron buenos resultados en comparación al control pero en algunos bioensayos no hubo diferencias entre estos y el de BAL libre lográndose extender la vida poscosecha de los frutos hasta 21 días.The non-climacteric fruits of the family Sapindaceae, as litchi and rambutan, are mainly affected by their weight loss and darkening of the pericarp due to degradation of their characteristic red pigments. Browning is favored by biochemical changes triggered by pH and dehydration. The color conservation treatments based on chemical procedures do not guarantee safety of the fruits for human consumption despite their effectiveness. Therefore, in this study the use of edible and biodegradable coatings that do not affect the consumer health are proposed. The objective was to develop coatings with chitosan and lactic bacteria that maintain the red color of the pericarp in rambutan and lychee fruits. Applications in litchi were performed both in the laboratory and in the field; the latter were carried out on the farms of cooperating producers in the Papaloapan Region in the Mexican State of Oaxaca. The functional characteristics of the components of the coatings were related to their antimicrobial activity, biodegradability and biocompatibility of chitosan; fungistatic and nematicide from neem oil (N); and lactic acid production in situ by Lactobacillus plantarum (LAB). Various formulations were prepared with these components by varying concentrations of 5g/L and 10 g/L, also the native chitosan was chemically modified by functionalization with hydroxypropylmethylcellulose (Q-g-HPMC), biological-chemical obtained chitosan (Q) and commercial (QC) and BAL were also tested along with chitosan free BQ in coacervates (CoBAL) and soluble complexes (QPBAL), CoBAL treatments formulated with chitosan and pectin in ratios of 1: 2 and QPBAL at 1: 1 respectively, due to the cationic and anionic behavior of both polymers. The emulsion treatments decreased the physiological weight loss (PFP %) of fruits, however other quality variables measured as the concentrations of total anthocyanins, cyanidin-3-rutinoside and catechin were low, which was attributed to oxidation of the vegetable oil used in the preparation of emulsions. Chitosans obtained by chemical and biological-chemical methods were compared; the latter showed the best results in the conservation of postharvest quality of fruits. The best treatment was using free BAL followed by soluble complexes and coacervates. Soluble complexes and coacervate treatments displayed better results than control, even when some bioassays did not show significant differences among the earlier and free BAL treatment. The postharvest life of fruits was extended up to 21 days

Relationship Between Dyslipidemia and Obesity in Children

Purpose: Dyslipidemia is a general term that refers to abnormal levels of lipids. The purpose of this research was to determine the relationship among the nutritional state and the percentage of body fat with the levels of lipids in 10 to 13 year old children living in the city of Durango, Mexico. Method: The study was carried out with 823 elementary school children. The selection was done at random. The biochemical studies were done in a subpopulation of 425 children. Each child underwent the following studies: sociodemographic, anthropometric and corporal composition. After fasting overnight, a venous blood sample was obtained. lipid profile including cholesterol, LDL-C, HDL-C and triglycerides were determined in serum. In order to classify lipid levels we used the reference values suggested by the National Cholesterol Education Program (NCEP). The desirable values were: TC \u3c170 mg\u3e/dl, HDL -C \u3e45 mg/dl, LDL -C \u3c110 mg\u3e/dl and TG \u3c100 mg\u3e/dl. The nutritional state was calculated according the age and sex specific BMI values developed by the CDC. Fat mass content was determined using a bioelectrical impedance analyzer (Tanita TBF-215). Statistical analyses were performed using SPSS14. Results: This study included 428 (52%) boys and 395 (48%) girls. Mean age was 11.5 years. The prevalence of overweight and obesity was 36.7. In the population studied we found abnormal levels of lipids in: cholesterol (41.8%), HDL-C (55.8%), LDL-C (32.3%) and TG (38.5%). The girls showed lower levels of HDL-C than the boys (p \u3c 0.05), the other lipoproteins were not statistical different ( p \u3e 0.05). The lipids levels (TC, LDL-C and TG) were higher in those with a BMI greater than 85 th percentile of BMI, and DHL-C was lower. In those with a body fat greater than 20%, all the lipids levels resulted abnormal. Conclusions: A high risk of dislypidemia was associated with gender, BMI and body fat

Systematic review and meta-analysis on the adverse events of rimonabant treatment: Considerations for its potential use in hepatology

<p>Abstract</p> <p>Background</p> <p>The cannabinoid-1 receptor blockers have been proposed in the management of obesity and obesity-related liver diseases (fatty liver as NAFLD or NASH). Due to increasing number of patients to be potentially treated and the need to assess the advantage of this treatment in terms of risk/benefit, we analyze the side events reported during the treatment with rimonabant by a systematic review and meta-analysis of all randomized controlled studies.</p> <p>Methods</p> <p>All published randomized controlled trials using rimonabant <it>versus </it>placebo in adult subjects were retrieved. Relative risks (RR) with 95% confidence interval for relevant adverse events and number needed to harm was calculated.</p> <p>Results</p> <p>Nine trials (n = 9635) were considered. Rimonabant 20 mg was associated with an increased risk of adverse event (RR 1.35; 95%CI 1.17-1.56), increased discontinuation rate (RR 1.79; 95%CI 1.35-2.38), psychiatric (RR 2.35; 95%CI 1.66-3.34), and nervous system adverse events (RR 2.35; 95%CI 1.49-3.70). The number needed to harm for psychiatric adverse events is 30.</p> <p>Conclusion</p> <p>Rimonabant is associated with an increased risk of adverse events. Despite of an increasing interest for its use on fatty liver, the security profile and efficacy it is needs to be carefully assessed before its recommendation. At present the use of rimonabant on fatty liver cannot be recommended.</p

A "Politically Robust" Experimental Design for Public Policy Evaluation, with Application to the Mexican Universal Health Insurance Program

We develop an approach to conducting large scale randomized public policy experiments intended to be more robust to the political interventions that have ruined some or all parts of many similar previous efforts. Our proposed design is insulated from selection bias in some circumstances even if we lose observations; our inferences can still be unbiased even if politics disrupts any two of the three steps in our analytical procedures; and other empirical checks are available to validate the overall design. We illustrate with a design and empirical validation of an evaluation of the Mexican Seguro Popular de Salud (Universal Health Insurance) program we are conducting. Seguro Popular, which is intended to grow to provide medical care, drugs, preventative services, and financial health protection to the 50 million Mexicans without health insurance, is one of the largest health reforms of any country in the last two decades. The evaluation is also large scale, constituting one of the largest policy experiments to date and what may be the largest randomized health policy experiment ever.Governmen

Antibacterial efficacy of gold and silver nanoparticles functionalized with the ubiquicidin (29–41) antimicrobial peptide

Recent studies have demonstrated that drug antimicrobial activity is enhanced when metallic nanoparticles are used as an inorganic support, obtaining synergic effects against microorganisms. The cationic antimicrobial peptide ubiquicidin 29–41 (UBI) has demonstrated high affinity and sensitivity towards fungal and bacterial infections. The aim of this research was to prepare and evaluate the antimicrobial efficacy of engineered multivalent nanoparticle systems based on silver or gold nanoparticles functionalized with UBI. Spectroscopy techniques demonstrated that NPs were functionalized with UBI mainly through interactions with the -NH2 groups. A significant increase in the antibacterial activity against Escherichia coli and Pseudomonas aeruginosawas obtainedwith the conjugateAgNP-UBI with regard to that of AgNP. No inhibitionof bacterial growth was observed with AuNP and AuNP-UBI using a nanoparticle concentration of up to 182 gmL−1.Nonetheless, silver nanoparticles conjugated to the UBI antimicrobial peptide may provide an alternative therapy for topical infections.This work was supported by the PROMEP-CA-68 (2013) project and The International Atomic Energy Agency (Contract no. 18358)

Preparation and characterization of a tumor-targeting dual-image system based on iron oxide nanoparticles functionalized with folic acid and rhodamine

Cancer is one of the diseases with most deaths worldwide, around 8.2 million annually. For this reason, several treatments and diagnostic tools have been investigated and developed over the past decades. Among them, a dual-image system has been developed to achieve and enhance the detection of cancer, which has not been done with systems currently available. The present study describes the preparation of a dual-image targeting system composed of magnetic iron oxide nanoparticles functionalized with folic acid and rhodamine; nanoparticles synthesis was achieved by a coprecipitation method; the functionalization was carried out by a carbodiimide with folic acid and/or the rhodamine isothiocyanate; conjugates were characterized by spectrometric techniques; toxicity was measured by cell proliferation assay on HeLa cells using progressive concentrations of functionalized nanoparticles. Cellular uptake assay was carried out by competitive assay on HeLa cells. Iron oxide magnetite nanoparticles, modified with folic acid and rhodamine, were successfully synthetized with a particle size lower than 20nm (TEM), EDS, HRTEM, and XDR showed highly crystalline Fe3O4 nanoparticles. Folic acid and rhodamine were conjugated with high efficiency. A significant selectivity and uptake, facilitated by surface modification of iron oxide nanoparticles with folic acid, were demonstrated.The multifunctional system showed suitable physicochemical and biological properties for cell targeting through folate receptors.This study was supported by the International Atomic Energy Agency (CRP-F22064, Contract no. 18358) and the Universidad Autónoma del Estado de México, through Project no. 3543/2013CHT

Prophylactic Activated Recombinant Factor VII in Liver Resection and Liver Transplantation: Systematic Review and Meta-Analysis

Intraoperative blood loss is a frequent complication of hepatic resection and orthotopic liver transplantation. Recombinant activated coagulation factor VII (rFVIIa) is a coagulation protein that induces hemostasis by directly activating factor X. There is no clear information about the prophylactic value of rFVIIa in hepatobiliary surgery, specifically in liver resection and orthotopic liver transplantation. The aim of this study was to assess the effect of rFVIIa prophylaxis to prevent mortality and bleeding resulting from hepatobiliary surgery.Relevant randomized trials were identified by searching The Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index. Randomized clinical trials comparing different rFVIIa prophylactic schemas against placebo or no intervention to prevent bleeding in hepatobiliary surgery were included. Adults undergoing liver resection, partial hepatectomy, or orthotopic liver transplantation were included. Dichotomous data were analyzed calculating odds ratios (ORs) and 95% confidence intervals (CIs). Continuous data were analyzed calculating mean differences (MD) and 95% CIs.Four randomized controlled trials were included. There were no significant differences between rFVIIa and placebo for mortality (OR 0.96; 95% CI 0.35-2.62), red blood cell units (MD 0.32; 95% CI -0.08-0.72) or adverse events (OR 1.55; 95% CI 0.97-2.49).The available information is limited, precluding the ability to draw conclusions regarding bleeding prophylaxis in hepatobiliary surgery using rFVIIa. Although an apparent lack of effect was observed in all outcomes studied, further research is needed

Relationship Between Leptin and Obesity in Mexican Chidren

Purpose: The expression and secretion of the leptin are thoroughly related with the regulation of food intake, energy balance and body fat. Obesity is defined as excess of body fat. The purpose of this research was to determine the relationship among the nutritional state and the percentage of body fat with the levels of leptin in 10 to 13 year old children living in the city of Durango, Mexico. Method: The study was carried out with 823 elementary school children. The selection was done at random. The biochemical studies were done in a subpopulation of 425 children. Each child underwent the following studies: sociodemographic, anthropometric and corporal composition. After fasting overnight, a venous blood sample was obtained. Leptin, glucose, lipid profile, insulin, Insulin growth factor, growth hormone, cortisol, TNF-alpha and C-reactive protein were determined in serum. The nutritional state was calculated according the age and sex specific BMI values developed by the CDC. Fat mass content was determined using a bioelectrical impedance analyzer (Tanita TBF-215). Statistical analyses were performed using SPSS14. Results: The studied population included 428 (52%) boys and 395 (48%) girls. Mean age was 11.50 years. The prevalence of overweight including obesity (≥85th percentile of the IMC) was 36.7%. The mean of the percentage of corporal fat in the women was 27.04 and in the males 22.05 (p \u3c0.05). The mean of the concentration of leptin in the women was 27.84 ng/mL and in the males 17.62 (p \u3c0.05). In the female group the leptin level increased with the age. The mean of leptin concentration in the group with ≥95th percentile of the IMC was higher (47.07 ng/mL) than those with 5-84.99th percentile of the IMC (14.01 ng/mL) (p \u3c0.05). The mean of leptin concentration in the group with \u3c20% body fat was lower (8.92 ng/mL) than the group with ≥40% body fat (59.94 ng/mL) (p \u3c0.05). Conclusions: The leptin level was associated with gender, body mass index (IMC) and body fat

Biodegradable poly(D,L-lactide-co-glycolide)/poly(L-γ-glutamic acid) nanoparticles conjugated to folic acid for targeted delivery of doxorubicin

A novel targeted drug delivery nanoparticle system based on poly(D,L-lactide-co-glycolide) acid (PLGA) for delivery of doxorubicin (DOX) was developed. DOX-PLGA NPs were obtained by the emulsification-solvent evaporation technique. Then, their surface was modified with poly(L-γ-glutamic acid) (γ-PGA) and finally conjugated to modified folic acid (FA) as a targeting ligand. The surface modification and FA conjugation were followed by UV–Vis and FT-IR spectroscopies. Morphology was observed by TEM/SEM. Particle size, PDI and zeta potential were measured using DLS studies. Encapsulation and loading efficiencies, and DOX release kinetics were determined. Specific uptake and cell viability of DOX-PLGA/γ-PGA-FA NPs were tested in HeLa cells. Quasi-spherical nanoparticleswith a particle size lower than 600nm(DLS)were obtained. Spectroscopic techniques demonstrated the successful surface modification with γ-PGA and FA conjugation. Release profile of DOX-PLGA/γ-PGA-FA NPs showed a release of 55.4 ± 0.6% after seven days, in an acidic environment. HeLa cells exhibited a decrease in viability when treated with DOX-PLGA/γ-PGA-AF NPs, and cellular uptake was attributed to FA receptor-mediated endocytosis. These results suggest that DOX-PLGA/γ-PGA-FA NPs are a potential targeted drug carrier for further applications in cancer therapy.This study was supported by the International Atomic Energy Agency (CRP-F22064, Contract No. 18358) and the Universidad Autónoma del Estado de México, through the project No. 3543/2013CHT

Study of the influence of Xanthate Derivative Structures on Copper Sulfide Mineral Adsorption Under Acidic Conditions

Artículo de investigación en revista indizadaAdsorption of commercial xanthate derivatives on copper sulfide mineral (covellite, CuS) was studied by kinetics and isotherm adsorption experiments. The adsorption of xanthate derivatives was confirmed by FTIR (Fourier transform infrared spectroscopy) and XPS (X-ray photoelectron spectroscopy) results. Experiments were performed with two different xanthate derivatives, C-4410 (O-pentyl S-2-propenyl ester) and C-4940 (isobutyl xanthogen ethyl formate), on individual doses of 0.05 g of powdered covellite. It was found that the equilibrium times at pH 2, 4, and 6 were different for both xanthate derivatives. The shortest times were achieved at pH 2 and 4. The results suggest that C-4110 can be used as collector in a wide range of pH, while C-4940 is limited to lower pH values. Pseudo first- and pseudo second-order kinetics models were thus applied to the experimental data for pH 2. The information obtained from the kinetics models combined with XPS allowed proposing the adsorption mechanism for the covellite-xanthate derivative pair. The adsorption takes place through a non-covalent interaction for C-4410 and chemisorption process for C-4940. The best-fitting isotherm models for C-4410 and C-4940 adsorption were Redlich–Peterson and Freundlich, respectively, which yield a maximum adsorption capacity of 57.07 mg g 1 for C-4410 and 44.62 mg g 1 for C-4940.CONACYT CB-254952-201