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1.
Braz J Biol ; 83: e270966, 2023.
Article in English | MEDLINE | ID: mdl-37283336

ABSTRACT

Terpenoids, also named terpenes or isoprenoids, are a family of natural products found in all living organisms. Many plants produce terpenoids as secondary metabolites, and these make up a large part of essential oils. One of most important characteristic is that the compounds are volatile, have odor and can be used in a variety of applications in different industrial segments and traditional medicine. Brazil has a rich and diverse flora that can be used as a source of research for obtaining new molecules. Within the Brazilian flora, it is worth mentioning the Caatinga as an exclusively Brazilian biome where plants adapt to a specific series of weather conditions and therefore become a great storehouse of the terpenoid compounds to be described herein. Fungal infections have become increasingly common, and a great demand for new agents with low toxicity and side effects has thus emerged. Scientists must search for new molecules exhibiting antifungal activity to develop new drugs. This review aims to analyze scientific data from the principal published studies describing the use of terpenes and their biological applications as antifungals.


Subject(s)
Oils, Volatile , Terpenes , Terpenes/pharmacology , Terpenes/metabolism , Antifungal Agents/pharmacology , Brazil , Oils, Volatile/pharmacology , Plants
2.
Cryo Letters ; 43(6): 357-367, 2022.
Article in English | MEDLINE | ID: mdl-36629831

ABSTRACT

BACKGROUND: Non-surgical artificial insemination techniques for sheep may benefit from larger numbers of sperm in the insemination dose because the ewe cervix is convoluted and often cannot be traversed with an insemination gun resulting in deposition of the sperm at the os cervix. OBJECTIVE: To compare a range of sperm concentrations when cryopreserving semen from Santa Ines rams and determine the effects of this on post-thaw quality. MATERIALS AND METHODS: One ejaculate from each ram (n = 10) was diluted to four sperm concentrations to obtain the following groups: G-400, G-800, G-1200, and G-1600 x 106 sperm/mL. The semen samples were packaged in 0.25 mL straws, cooled to 5 degree C, cryopreserved in liquid nitrogen vapor, thawed in a water bath (40 degree C per 20 s), and were analyzed for computerized kinetics, capacitation and acrosome integrity, and plasma membrane integrity of sperm. RESULTS: The G-400 treatment resulted in samples with the highest linearity and progressive motion (P < 0.05) and had significantly greater plasma membrane integrity, and lower capacitation and acrosome reaction rates compared to G-1600 (P < 0.05). Overall, use of the G-400 treatment resulted in better kinetics, less plasma membrane damage and less early capacitation. However, despite reducing the ejaculate yield and increasing the costs of the semen freezing process, the G-800 and G-1200 treatments make a greater absolute number of sperm with good kinetics, plasma membrane integrity and capacitation status available. CONCLUSION: Ram sperm concentration impacts cryopreservation, and higher concentrations may be advantageous if a single artificial insemination protocol is desirable. doi.org/10.54680/fr22610110812.


Subject(s)
Cryopreservation , Semen Preservation , Female , Male , Sheep , Animals , Cryopreservation/veterinary , Cryopreservation/methods , Semen , Semen Preservation/veterinary , Semen Preservation/methods , Sperm Motility , Spermatozoa , Sheep, Domestic
3.
Microb Pathog ; 147: 104273, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32473391

ABSTRACT

The present study was developed to characterize, at the species level, 34 strains of Aeromonas spp., previously isolated from stressed tambaqui fish (Colossoma macropomum), to elucidate virulence factors, as well as their antibiotic resistance profile. Amplification of the gyrB gene identified the strains as A. hydrophila, A. dhakensis, A. caviae, A. veronii and A. jandaei. Bacterial virulence was evaluated by enzymatic assays for phenotypical production of hemolysins, proteases and lipases followed by the search for genes codifying the enzymes ß-hemolysin, serine protease and lipase. Phenotypical production of virulence factors was diversified and proteolytic activity demonstrated to be a common expression among the strains. On the other hand, the lip gene encoding extracellular lipase was the most expressed. Furthermore, A. hydrophila was the most prevalent species isolated from tambaqui in our work.


Subject(s)
Aeromonas , Characiformes , Gram-Negative Bacterial Infections , Aeromonas/genetics , Animals , Anti-Bacterial Agents , Gram-Negative Bacterial Infections/veterinary , Virulence
4.
J Food Sci Technol ; 56(6): 3164-3169, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31205372

ABSTRACT

This study analyzes the lipid composition and the oxidative stability of oils of Sapindaceae and Meliaceae seeds. The oil content ranged from 14.7% (Guarea guidonia) to 30.1% (Allophylus puberulus and Paullinia elegans). Ten fatty acids were identified in seed oils. Guarea guidonia seeds accumulated mainly oleic (44.9%) and linoleic (24.1%) acid, whereas the unusual gondoic and paullinic acids were identified in A. puberulus (15.8%; 8.9%) and P. elegans (14.4%; 44.2%), respectively. The oil of P. elegans had the highest oxidative stability (16.2 h.). Tocopherol predominated in A. puberulus (10.4 mg/100 g) and tocotrienol predominated in G. guidonea and P. elegans (2.6 mg/100 g). The vitamers α-tocopherol, γ-tocopherol, and γ-tocotrienol were found in the studied oils. ß-carotene was predominantly detected in the oil of A. puberulus seeds (22.4 µg/g). Guarea guidonia seed oil has a high potential in food due to richness in essential fatty acids. In turn, A. puberulus and P. elegans oils could be suggested for other industrial purposes (e.g., biodiesel, varnishes, paints, soaps, or oleochemicals) due to their content of long-chain fatty acids.

6.
Lett Appl Microbiol ; 67(1): 54-63, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29603295

ABSTRACT

Zymomonas mobilis has long attracted attention owing to its capacity to ferment hexose to ethanol. From a taxonomic viewpoint, Z. mobilis is a unique species of the genus Zymomonas, separated into three subspecies, Z. mobilis subsp. mobilis, Z. mobilis subsp. pomaceae and Z. mobilis subsp. francensis on the basis of physiological tests, which are often unreliable owing to the genetic proximity among these species. Currently, the use of molecular techniques is more appropriate for identification of these bacterial subspecies. In this study, the 32 strains of Z. mobilis present in the UFPEDA bacterial collection were characterized using molecular techniques, such as sequencing of the 16S rDNA gene and its theoretical restriction profile, classifying them as members of the subspecies, Z. mobilis subsp. mobilis. In addition, anaerobic cultivations were performed, which showed the biological diversity of the strains in terms of growth, sugar consumption and ethanol production. From these results, it was possible to identify the strain Z-2-80 as a promising bacterium for use in the fermentation process. SIGNIFICANCE AND IMPACT OF THE STUDY: Zymomonas mobilis is a bacterium of great relevance to biotechnology, owing to its capacity to ferment hexose to ethanol. On a molecular basis, 32 isolates were identified as Z. mobilis subsp. mobilis. However, intraspecific diversity was identified when these were grown under strictly anaerobic conditions. The results obtained from this study suggest a strain of Z. mobilis as an alternative for use in the fermentation process.


Subject(s)
Bioreactors/microbiology , DNA, Bacterial/genetics , Ethanol/metabolism , Zymomonas/classification , Zymomonas/metabolism , Anaerobiosis , Brazil , DNA, Ribosomal/genetics , Fermentation , Hexoses/metabolism , RNA, Ribosomal, 16S/genetics , Zymomonas/genetics , Zymomonas/isolation & purification
7.
J Anim Physiol Anim Nutr (Berl) ; 102(1): 122-130, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28032379

ABSTRACT

Changes in physiological parameters that are induced by acute exercise on a treadmill in healthy military dogs have not been thoroughly investigated, especially with regard to age. This study investigated the effects of acute exercise on a treadmill on cardiovascular function, biochemical parameters and gastric antral motility in military dogs. Thermography was used to assess variations in superficial hindlimb muscle temperature. Nine healthy dogs were distributed into three groups according to their age (Group I: 25 ± 7 months; Group II: 51 ± 12 months; Group III: 95 ± 10 months) and sequentially subjected to running exercise on a treadmill for 12 min (3.2 km/h at 0° incline for 4 min, 6.4 km/h at 0° incline for 4 min and 6.4 km/h at 10° incline for 4 min). Heart rate, systolic and diastolic arterial pressure (DAP), gastric motility, haematocrit and biochemical analyses were performed at rest and after each session of treadmill exercise. Infrared thermographic images of muscles in the pelvic member were taken. Exercise decreased DAP in Group I, increased systolic arterial pressure in Groups II and III and increased mean arterial pressure in Group III (all p < 0.05). After the exercise protocol, plasma creatine kinase and aspartate aminotransferase levels increased only in Group I (p < 0.05). Exercise increased heart rate and decreased the gastric motility of a solid meal at 180 min in all groups (all p < 0.05). Exercise also elevated temperature in the femoral biceps muscles in Group I compared with the older dogs. The results indicate that acute exercise decreased gastric motility in dogs, regardless of age, and caused more pronounced cardiovascular changes in older dogs than in younger dogs. Acute exercise also altered biochemical parameters and superficial hindlimb muscle temperature in younger military dogs.


Subject(s)
Blood Pressure , Body Temperature/physiology , Dogs/physiology , Gastrointestinal Motility/physiology , Heart Rate , Physical Conditioning, Animal/physiology , Animals , Exercise Test/veterinary , Male , Military Personnel , Muscle, Skeletal/physiology , Physical Exertion
8.
Poult Sci ; 97(3): 1073-1081, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-29253211

ABSTRACT

In this study, the lipid profile of 5 different edible tissues (leg, thigh, heart, gizzard, and liver) of ostrich was analyzed. Ostrich edible tissues presented a low fat content (<5 g/100 g wet basis). Gizzard and heart revealed the highest amounts of total cholesterol (1.77 and 1.47 mg/g wet basis, respectively), differing significantly from all other tissues (which averaged 0.95 mg/g wet basis). The main tocochromanol in all tissues was α-tocopherol (10.3 µg/g wet basis in heart and an average of 3.4 µg/g wet basis for all the remaining tissues). All the samples presented a fatty acid profile, dominated by polyunsaturated fatty acids (PUFA) (>38%), namely, linoleic and arachidonic acids. The leg presented simultaneously the highest PUFA/saturated fatty acids (SFA), the lowest n-6/n-3 ratios, and the most favorable lipid quality indices among all tissues in comparison.


Subject(s)
Food Quality , Lipids/analysis , Meat/analysis , Nutritive Value , Struthioniformes/physiology , Animals , Gizzard, Avian/chemistry , Heart/physiology , Liver/chemistry , Myocardium/chemistry
9.
Food Funct ; 7(6): 2780-8, 2016 Jun 15.
Article in English | MEDLINE | ID: mdl-27220688

ABSTRACT

The present study was performed on olives from two Algerian cultivars (Limli and Rougette de Metidja) with different rates of attack by the Bactrocera oleae fly (0%, not attacked; 100%, all attacked; and real attacked %) and the corresponding olive oils. The aim was to verify the attack effect on quality parameters (free fatty acid, peroxide value, K232 and K270, oxidation stability), bioactive compounds (fatty acids and tocopherols, and total phenols and flavonoids), and on the antioxidant (reducing power, FRAP, ß-carotene bleaching inhibition, ABTS and DPPH) and antibacterial (against 8 referenced human enteropathogenic bacteria by the agar disc diffusion method) capacities. Oils from infested olives were downgraded to the virgin olive oil category. Rougette de Metidja, the cultivar with a higher drupe size, was more attacked than Limli. The B. oleae attack causes an important decrease in the total phenolic contents (>30%) but to a lesser degree in the case of tocopherols. Among them, α-tocopherol is the most affected. The antioxidant and antibacterial activities were highly correlated with phenolic levels. The results of this study show the importance of controlling the fly attack because it causes a decrease in the beneficial health effects of olive oils.


Subject(s)
Anti-Bacterial Agents/analysis , Antioxidants/analysis , Food Quality , Olea , Olive Oil/analysis , Tephritidae , Animals , Carotenoids/analysis , Enteropathogenic Escherichia coli/drug effects , Fatty Acids, Nonesterified/analysis , Flavonoids/analysis , Food Contamination , Peroxides/analysis , Phenols/analysis , Tocopherols/analysis
10.
Rev. bras. plantas med ; 18(2,supl.1): 597-604, 2016. tab, graf
Article in Portuguese | LILACS | ID: biblio-830061

ABSTRACT

RESUMO Este trabalho analisa o efeito larvicida do óleo Zingiber officinale Roscoe contra larvas em terceiro estágio do mosquito Aedes aegypti. Extraiu-se quantitativamente o óleo essencial por hidrodestilação e calculou-se a CL50 do óleo, a partir dos métodos de Reed-Muench e Pizzi, respectivamente. O óleo essencial obteve CL50 de 76,07 (±2,24) μg mL-1 e rendimento de 0,52% m/v. Os resultados indicam que o óleo essencial avaliado é composto por substâncias que propiciam efeito larvicida contra Aedes aegypti.


ABSTRACT This study analyzes the larvicidal effect of the oil of Zingiber officinale Roscoe against larvae in third stage of the mosquito Aedes aegypti (Linnaeus 1792). The essential oil was extracted quantitatively by hydrodistillation and we calculated the oil’s LC50 from Reed-Muench (1938) and Pizzi (1950) methods, respectively. The essential oil obtained LC50 of 76.07 (±2.24) ug mL-1, and yield of 0.52% m/v. The results indicate that the essential oil assessed has substances that provide larvicidal effect against Aedes aegypti.


Subject(s)
Oils, Volatile/analysis , Aedes/classification , Larvicides/classification , Zingiber officinale/classification
11.
Biomater Sci ; 3(4): 581-5, 2015 Apr.
Article in English | MEDLINE | ID: mdl-26222417

ABSTRACT

We propose a novel hanging spherical drop system for anchoring arrays of droplets of cell suspension based on the use of biomimetic superhydrophobic flat substrates, with controlled positional adhesion and minimum contact with a solid substrate. By facing down the platform, it was possible to generate independent spheroid bodies in a high throughput manner, in order to mimic in vivo tumour models on the lab-on-chip scale. To validate this system for drug screening purposes, the toxicity of the anti-cancer drug doxorubicin in cell spheroids was tested and compared to cells in 2D culture. The advantages presented by this platform, such as feasibility of the system and the ability to control the size uniformity of the spheroid, emphasize its potential to be used as a new low cost toolbox for high-throughput drug screening and in cell or tissue engineering.


Subject(s)
Biocompatible Materials/chemistry , Drug Evaluation, Preclinical/instrumentation , High-Throughput Screening Assays/methods , Spheroids, Cellular/cytology , Tissue Engineering/methods , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Biomimetics , Biotechnology , Cell Culture Techniques , Cell Line, Tumor , Cell Survival/drug effects , Doxorubicin/chemistry , Doxorubicin/pharmacology , Humans
12.
Food Funct ; 6(3): 938-46, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25653232

ABSTRACT

Consumers nowadays are playing an active role in their health-care. A special case is the increasing number of women, who are reluctant to use exogenous hormone therapy for the treatment of menopausal symptoms and are looking for complementary therapies. However, food supplements are not clearly regulated in Europe. The EFSA has only recently begun to address the issues of botanical safety and purity regulation, leading to a variability of content, standardization, dosage, and purity of available products. In this study, isoflavones (puerarin, daidzin, genistin, daidzein, glycitein, genistein, formononetin, prunetin, and biochanin A) from food supplements (n = 15) for menopausal symptoms relief are evaluated and compared with the labelled information. Only four supplements complied with the recommendations made by the EC on the tolerable thresholds. The intestinal bioavailability of these compounds was investigated using Caco-2 cells. The apparent permeability coefficients of the selected isoflavonoids across the Caco-2 cells were affected by the isoflavone concentration and product matrix.


Subject(s)
Dietary Supplements/analysis , Enterocytes/metabolism , Intestinal Absorption , Isoflavones/analysis , Phytoestrogens/analysis , Absorption, Physiological , Australia , Caco-2 Cells , Cell Membrane Permeability , Dietary Supplements/economics , Dietary Supplements/standards , European Union , Female , Food Additives/adverse effects , Food Additives/analysis , Food Additives/chemistry , Food Inspection , Food Labeling , Guidelines as Topic , Humans , Isoflavones/chemistry , Isoflavones/metabolism , Molecular Structure , Osmolar Concentration , Phytoestrogens/chemistry , Phytoestrogens/metabolism , Phytoestrogens/standards , Postmenopause , Self Care , United States
13.
Genet Mol Res ; 13(4): 9795-805, 2014 Nov 27.
Article in English | MEDLINE | ID: mdl-25501189

ABSTRACT

Drought and rice blast disease caused by Magnaporthe oryzae are two of the most serious threats to global rice production. To explore the mechanisms underlying gene expression induced in rice by stresses, studies involving transcriptome analyses have been conducted over the past few years. Thus, it is crucial to have a reliable set of reference genes to normalize the expression levels of rice genes affected by different stresses. To identify potential reference genes for studies of the differential expression of target genes in rice under M. oryzae infection and drought conditions, the present study evaluated five housekeeping genes for the normalization of gene expression. The stability of the expression of these genes was assessed using the analytical software packages geNorm and NormFinder. For all samples analyzed, the stability rank was UBQ5 > GAPDH > eIF-4α> ß-TUB > 18S rRNA. The data showed that the UBQ5, GAPDH, and eIF-4αgenes are appropriate, high-performing reference genes and will be highly useful in future expression studies of fungal infections and drought in rice.


Subject(s)
Gene Expression Regulation, Plant , Genes, Essential , Genes, Plant , Oryza/genetics , Real-Time Polymerase Chain Reaction/standards , Droughts , Eukaryotic Initiation Factor-4A/genetics , Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)/genetics , Magnaporthe/pathogenicity , Magnaporthe/physiology , Oryza/microbiology , Plant Diseases/genetics , Plant Diseases/microbiology , Reference Standards , Stress, Physiological , Transcriptome , Ubiquitin/genetics
14.
Carbohydr Polym ; 112: 264-70, 2014 Nov 04.
Article in English | MEDLINE | ID: mdl-25129743

ABSTRACT

Chemical composition and biological properties of Aloe vera (AV), a tropical plant, explain its potential use for cosmetic, nutritional and biomedical applications. AV gel present in AV leaves is rich in several compounds, nutrients and polysaccharides. This work proposes using AV gel complex structure and chemical composition, associated with freeze-drying, to produce sponges. To increase the structures stability in aqueous media, a thin coating of gellan gum (GG), was applied onto AV gel. AV-based sponges showed a heterogeneous porous formation, interconnected pores and good porosity (72-77%). The coating with a GG layer onto AV influenced the stability, swelling behavior and mechanical properties of the resulting sponges. Moreover, sponges provided the sustained release of BSA-FTIC, used as a model protein, over 3 weeks. Also, in vitro cell culture studies evidenced that sponges are not cytotoxic for a mouse fibroblast-like cell line. Therefore, developed AV-based sponges have potential use in biomedical applications.


Subject(s)
Aloe/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacokinetics , Animals , Biocompatible Materials/pharmacology , Cell Line/drug effects , Drug Delivery Systems , Drug Stability , Fibroblasts/drug effects , Fluorescein-5-isothiocyanate/analogs & derivatives , Freeze Drying , Gels/chemistry , Hydrogen-Ion Concentration , Mice , Microscopy, Electron, Scanning , Polysaccharides, Bacterial/chemistry , Porosity , Serum Albumin, Bovine/pharmacokinetics , X-Ray Microtomography
15.
Food Chem ; 151: 311-6, 2014 May 15.
Article in English | MEDLINE | ID: mdl-24423538

ABSTRACT

The mineral content (phosphorous (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu)) of eight ready-to-eat baby leaf vegetables was determined. The samples were subjected to microwave-assisted digestion and the minerals were quantified by High-Resolution Continuum Source Atomic Absorption Spectrometry (HR-CS-AAS) with flame and electrothermal atomisation. The methods were optimised and validated producing low LOQs, good repeatability and linearity, and recoveries, ranging from 91% to 110% for the minerals analysed. Phosphorous was determined by a standard colorimetric method. The accuracy of the method was checked by analysing a certified reference material; results were in agreement with the quantified value. The samples had a high content of potassium and calcium, but the principal mineral was iron. The mineral content was stable during storage and baby leaf vegetables could represent a good source of minerals in a balanced diet. A linear discriminant analysis was performed to compare the mineral profile obtained and showed, as expected, that the mineral content was similar between samples from the same family. The Linear Discriminant Analysis was able to discriminate different samples based on their mineral profile.


Subject(s)
Minerals/analysis , Plant Leaves/chemistry , Spectrophotometry, Atomic/methods , Vegetables/chemistry , Digestion
16.
Clin Exp Allergy ; 44(3): 319-41, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24382327

ABSTRACT

Food-induced allergies have been regarded as an emergent problem of public health. Classified as important allergenic ingredients, the presence of walnut and other nuts as hidden allergens in processed foods constitutes a risk for sensitized individuals, being a real problem of allergen management. Attending to the increasing importance dedicated to walnut allergy, this review intends to provide the relevant and up-to-date information on main issues such as the prevalence of walnut allergy, the clinical threshold levels, the molecular characterization of walnut allergens and their clinical relevance, as well as the methodologies for walnut allergen detection in foods. As the walnut used in human diet comes from Juglans regia and Juglans nigra, the molecular characterization of the allergens from both species included in the prolamins (Jug r 1, Jug n 1 and Jug r 3), cupins (Jug r 2, Jug n 2 and Jug r 4) and profilins (Jug r 5), together with respective clinical relevance, were compiled in this review. The most recent progresses on walnut allergen detection techniques (protein- and DNA-based) are described and critically compared, including the emergent multitarget approaches.


Subject(s)
Allergens/immunology , Food Hypersensitivity/immunology , Juglans/adverse effects , Antigens, Plant/immunology , Desensitization, Immunologic , Food Hypersensitivity/diagnosis , Food Hypersensitivity/epidemiology , Food Hypersensitivity/prevention & control , Food Hypersensitivity/therapy , Humans , Prevalence
17.
J Chromatogr A ; 1327: 118-31, 2014 Jan 31.
Article in English | MEDLINE | ID: mdl-24438834

ABSTRACT

Ready-to-eat baby-leaf vegetables market has been growing and offering to consumers convenient, healthy and appealing products, which may contain interesting bioactive compounds. In this work, the composition and the evolution of the phenolic compounds from different baby-leaf vegetables during refrigerated storage was studied. The phenolic compounds were extracted using pressurized liquid extraction (PLE) and the phenolic profile of each sample was analyzed and quantified by using LC-MS and LC-DAD methods, respectively, at the beginning and at the end of a 10-day storage period. The baby-leaf vegetables studied included green lettuce, ruby red lettuce, swiss chard, spinach, pea shoots, watercress, garden cress, mizuna, red mustard, wild rocket and spearmint samples and a total of 203 phenolic compounds were tentatively identified and quantified. The main naturally phenolic compounds identified correspond to glycosylated flavonoids, with exception of green lettuce and spearmint leaves which had a higher content of hydroxycinnamic acids. Quantification of the main compounds showed a 10-fold higher content of total phenolic content of ruby red lettuce (483mgg(-1)) in relation to the other samples, being the lowest values found in the garden cress (12.8mgg(-1)) and wild rocket leaves (8.1mgg(-1)). The total phenolic content only showed a significant change (p<0.05) after storage in the green lettuce (+17.5%), mizuna (+7.8%), red mustard (-23.7%) and spearmint (-13.8%) leaves. Within the different classes of phenolic compounds monitored, the flavonols showed more stable contents than the hydroxycinnamic and hydroxybenzoic acids, although the behavior of each compound varied strongly among samples.


Subject(s)
Phenols/analysis , Plant Leaves/chemistry , Vegetables/chemistry , Chromatography, High Pressure Liquid/methods , Food Analysis , Mass Spectrometry/methods
18.
Biosens Bioelectron ; 51: 195-200, 2014 Jan 15.
Article in English | MEDLINE | ID: mdl-23962706

ABSTRACT

There is an imminent need for rapid methods to detect and determine pathogenic bacteria in food products as alternatives to the laborious and time-consuming culture procedures. In this work, an electrochemical immunoassay using iron/gold core/shell nanoparticles (Fe@Au) conjugated with anti-Salmonella antibodies was developed. The chemical synthesis and functionalization of magnetic and gold-coated magnetic nanoparticles is reported. Fe@Au nanoparticles were functionalized with different self-assembled monolayers and characterized using ultraviolet-visible spectrometry, transmission electron microscopy, and voltammetric techniques. The determination of Salmonella typhimurium, on screen-printed carbon electrodes, was performed by square-wave anodic stripping voltammetry through the use of CdS nanocrystals. The calibration curve was established between 1×10(1) and 1×10(6) cells/mL and the limit of detection was 13 cells/mL. The developed method showed that it is possible to determine the bacteria in milk at low concentrations and is suitable for the rapid (less than 1h) and sensitive detection of S. typhimurium in real samples. Therefore, the developed methodology could contribute to the improvement of the quality control of food samples.


Subject(s)
Cadmium Compounds/chemistry , Electrochemical Techniques/methods , Ferric Compounds/chemistry , Gold/chemistry , Milk/microbiology , Salmonella typhimurium/isolation & purification , Sulfides/chemistry , Animals , Antibodies, Immobilized/chemistry , Immunoassay/methods , Limit of Detection , Magnetite Nanoparticles/chemistry
19.
Neuroscience ; 259: 223-31, 2014 Feb 14.
Article in English | MEDLINE | ID: mdl-24316471

ABSTRACT

Supplementation with omega-3 has been identified as an adjunctive alternative for the treatment of psychiatric disorders, in order to minimize symptoms. Considering the lack of understanding concerning the pathophysiology of schizophrenia, the present study hypothesized that omega 3 prevents the onset of symptoms similar to schizophrenia in young Wistar rats submitted to ketamine treatment. Moreover, the role of oxidative stress in this model was assessed. Omega-3 (0.8g/kg) or vehicle was given by orogastric gavage once daily. Both treatments were performed during 21days, starting at the 30th day of life in young rats. After 14days of treatment with omega-3 or vehicle, a concomitant treatment with saline or ketamine (25mg/kg ip daily) was started and maintained until the last day of the experiment. We evaluated the pre-pulse inhibition of the startle reflex, activity of antioxidant systems and damage to proteins and lipids. Our results demonstrate that supplementation of omega-3 prevented: decreased inhibition of startle reflex, damage to lipids in the hippocampus and striatum and damage to proteins in the prefrontal cortex. Furthermore, these changes are associated with decreased GPx in brain tissues evaluated. Together, our results suggest the prophylactic role of omega-3 against the outcome of symptoms associated with schizophrenia.


Subject(s)
Brain Injuries/diet therapy , Brain Injuries/etiology , Fatty Acids, Omega-3/administration & dosage , Mental Disorders/prevention & control , Schizophrenia/complications , Animals , Brain/drug effects , Brain/metabolism , Disease Models, Animal , Dose-Response Relationship, Drug , Glutathione Peroxidase/metabolism , Ketamine/toxicity , Male , Malondialdehyde/metabolism , Mental Disorders/etiology , Oxidative Stress/drug effects , Protein Carbonylation/drug effects , Rats , Rats, Wistar , Schizophrenia/chemically induced , Schizophrenia/pathology , Sensory Gating/drug effects , Superoxide Dismutase/metabolism , Thiobarbituric Acid Reactive Substances/metabolism
20.
J Mater Chem B ; 2(34): 5627-5638, 2014 Sep 14.
Article in English | MEDLINE | ID: mdl-32262197

ABSTRACT

Nanocomposite hydrogels were prepared in a combinatorial way with chitosan, bioglass nanoparticles (BG-NPs) and distinct amounts of crosslinker (genipin), in a total of 30 formulations. Such miniaturized hydrogels were prepared by dispensing the precursor solutions in wettable spots previously patterned onto superhydrophobic surfaces. The chips were used as platforms to analyze the biomaterials on-chip both for mechanical/viscoelastic and cell-biomaterial interactions. We adapted a mechanical dynamic analyzer (DMA) in order to perform the in situ totally unconfined solid-state rheological characterization of biomaterials under physiological-like conditions. We concluded that the viscoelastic properties of the hydrogels are dependent on the three factors studied. Besides influencing biomaterials' mechanical properties, bioglass fillers also confer bioactivity. We immersed the chips with 20 distinct biomaterial formulations in a cell suspension of MC3T3-E1 pre-osteoblasts and quantified - using image analysis compatible with the maintenance of the integrity of the chip - selective cell adhesion after 1 day of cell culture, as well as cell proliferation and cell morphology at day 3. Linear regression studies showed that for the range of conditions studied herein, neither cell adhesion nor proliferation depended directly on the biomaterials' mechanical/viscoelastic properties. Rather, cell proliferation was favoured in the presence of an intermediate amount of BGNPs (12.5% w/w) for all chitosan/genipin conditions, especially in softer hydrogels (2% (w/v) chitosan, 2.5% (w/w) genipin). This hit-spotted condition also favoured cell spreading. Interestingly, the elastic modulus measured for this formulation meets the values reported for the granulation tissue occurring during bone regeneration, where fibroblasts produce collagen. We believe that this approach will facilitate the complete on-chip rapid study of miniaturized biomaterials, in order to get more adequate formulations to be used in tissue engineering or other biomedical applications.

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