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1.
Front Immunol ; 10: 1732, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428087

RESUMO

Previous studies indicate that B-lymphocytes play a key role activating diabetogenic T-lymphocytes during the development of autoimmune diabetes. Recently, two transgenic NOD mouse models were generated: the NOD-PerIg and the 116C-NOD mice. In NOD-PerIg mice, B-lymphocytes acquire an activated proliferative phenotype and support accelerated autoimmune diabetes development. In contrast, in 116C-NOD mice, B-lymphocytes display an anergic-like phenotype delaying autoimmune diabetes onset and decreasing disease incidence. The present study further evaluates the T- and B-lymphocyte phenotype in both models. In islet-infiltrating B-lymphocytes (IIBLs) from 116C-NOD mice, the expression of H2-Kd and H2-Ag7 is decreased, whereas that of BAFF, BAFF-R, and TACI is increased. In contrast, IIBLs from NOD-PerIg show an increase in CD86 and FAS expression. In addition, islet-infiltrating T-lymphocytes (IITLs) from NOD-PerIg mice exhibit an increase in PD-1 expression. Moreover, proliferation assays indicate a high capacity of B-lymphocytes from NOD-PerIg mice to secrete high amounts of cytokines and induce T-lymphocyte activation compared to 116C B-lymphocytes. This functional variability between 116C and PerIg B-lymphocytes ultimately results in differences in the ability to shape T-lymphocyte phenotype. These results support the role of B-lymphocytes as key regulators of T-lymphocytes in autoimmune diabetes and provide essential information on the phenotypic characteristics of the T- and B-lymphocytes involved in the autoimmune response in autoimmune diabetes.

2.
Food Res Int ; 121: 28-38, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31108750

RESUMO

The objective of this study was to investigate the impact of endo- and exo-peptidase treatment on certain structural characteristics of peptides and volatile compounds of porcine hemoglobin and whole blood hydrolysates. Porcine hemoglobin and whole blood were hydrolyzed by endo- and exo-peptidases. The presence of exopeptidases reduced the bitterness and altered the volatile profiles of protein hydrolysates. Exopeptidase treatment can release terminal amino acids from peptides, which in turn may contribute to formation of volatile compounds by Maillard reactions. In contrast, endopeptidases conferred a slightly bitter taste and different volatile profiles. For hemoglobin hydrolysates, principal component analysis revealed that proteases were categorized into three groups based on endo- or exo-peptidase activity. Whole blood is a more complex raw material, yet the proteases were still categorized in a similar fashion. This work contributes to understanding structural characteristics responsible for taste and volatile profiles of protein hydrolysates.

3.
J Food Sci Technol ; 55(10): 4287-4296, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30228427

RESUMO

This study investigates the potential of novel heme-ligand complexes, derived from heme-iron isolated from porcine hemoglobin by enzymatic hydrolysis, to use as pigments for meat products. Five alternatives to sodium nitrite were identified as possible heme ligands and stabilizing agents of the red conformation of heme. The effects of 4-methylimidazole, methyl nicotinate, pyrrolidine, piperidine, pyrazine and sodium nitrite (as comparative benchmark) on the color of heme-iron extract and pure hemin standard were studied in solution. The ligand affinity and heme-ligand stability was assessed over time in solution by UV-Vis absorbance spectroscopy and CIELAB color space parameters. The CIE redness score a* was used as a single measurement to propose a predictive model based on the following parameters: heme source (heme-iron extract or hemin standard), heme-to-ligand molar ratio (1:20 to 1:300), and storage time (up to 32 days). The optimal concentration at which each ligand can be added to either heme source, as well as the stability of the red color of the formed heme-ligand complexes in-solution was determined. Heme-iron extract-derived samples showed increased redness and color stability as compared to their hemin counterparts. No ligand showed as much affinity for heme as sodium nitrite. As the most promising ligand candidates, methyl nicotinate and 4-methylimidazole started to show color changes at a 1:50 molar ratio, but higher amounts (1:100 and 1:300, respectively) were required to attain the maximum redness possible with the highest stability.

4.
Meat Sci ; 145: 415-424, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30055433

RESUMO

The aim of the study was to characterize Maillard reactions in meat under different cooking treatments. Considered temperature-time combinations included raw samples (control), 58, 80, 98 and 160 °C for 72 min, 118 °C for 8 min and 58 °C for 17 h. Furosine, a marker for heat treatment, was detected in all groups with roasting having a 4-fold increase over the control. Sous-vide treatment at 80 °C, boiling and autoclaving also contribute to a significant increase in furosine. Nɛ-carboxymethyllysine, an indicator for advanced glycation end products, showed negligible amount in control, but increased with cooking temperature, with oven samples showing the highest values. A similar increasing trend was observed in lanthionine, covalently bonded protein crosslinks, which arises due to severe thermal regimes. Simultaneously, glycation and deamidation formation were tracked in meat proteins through peptidomics to highlight residue level changes that might affect nutrient value in processed muscle based foods.


Assuntos
Culinária/métodos , Proteínas na Dieta/análise , Produtos Finais de Glicação Avançada/análise , Temperatura Alta , Reação de Maillard , Processamento de Proteína Pós-Traducional , Carne Vermelha/análise , Alanina/análogos & derivados , Alanina/análise , Animais , Humanos , Lisina/análogos & derivados , Lisina/análise , Proteínas Musculares/análise , Valor Nutritivo , Peptídeos/análise , Estabilidade Proteica , Sulfetos/análise , Suínos , Paladar
5.
Meat Sci ; 141: 57-65, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29605744

RESUMO

This study aimed to address the proteolytic phenomena taking place in pork loins during prolonged storage at superchilling (SC) temperature. Loins were stored at either chilling (CH) conditions (2-4 °C) for 4 weeks or at SC temperature (around -1 °C) for 12 weeks. Storage at SC temperatures slowed down the rate of proteolysis in pork loins, so that final levels of most indicators for proteolysis, including after 12 weeks of SC storage were similar to those after 4 weeks at CH conditions. Consequently, the texture of SC pork under extended storage was not so different to that of CH pork. However, total amino acid content peaked by the end of SC storage, pointing out to a potential ongoing exopeptidase activity. Overall, proteolysis seemed to be slowed down in pork at SC conditions, with similar levels for most indicators after 12 weeks of SC storage or 4 weeks at CH conditions.


Assuntos
Temperatura Baixa , Manipulação de Alimentos , Carne Vermelha/análise , Animais , Calpaína/metabolismo , Catepsina B , Catepsina L , Suínos , Fatores de Tempo
6.
J Sci Food Agric ; 98(14): 5302-5312, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29656385

RESUMO

BACKGROUND: The omega-3 enrichment of ready-to-cook meat products by microencapsulated fish oil (MFO) addition was analyzed. Accordingly, three batches of chicken nuggets were prepared: (i) control (C); (ii) enriched in bulk fish oil (BFO); and (iii) with added MFO. Sensory features, acceptability, oxidative stability and volatile compounds were analyzed. RESULTS: MFO nuggets did not differ from C ones with respect to any sensory trait. BFO showed increased juiciness and saltiness but decreased meat flavor. Acceptability was not affected by enrichment. Consumers were not able to differentiate between C and MFO in a triangle test, although they could clearly identify BFO nuggets. Higher levels of lipid and protein oxidation indicators and of volatile compounds from fatty acid oxidation were found in BFO nuggets compared to C and MFO nuggets. CONCLUSION: Enrichment of ready-to-cook meat products in omega-3 fatty acids with MFO provides both lipid and protein oxidative protection without changes in sensory quality. © 2018 Society of Chemical Industry.


Assuntos
Fast Foods/análise , Ácidos Graxos Ômega-3/química , Aditivos Alimentares/química , Lipídeos/química , Produtos da Carne/análise , Culinária , Humanos , Oxirredução , Proteínas/química , Paladar
7.
Meat Sci ; 140: 134-144, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29558677

RESUMO

The impact of thermal processing on meat proteins oxidation was investigated. Cooking treatments included 58 °C for either 72 min or 17 h (mimicking low temperature-long time sous vide cooking), 80, 98 and 160 °C for 72 min (mimicking common cooked meat products, stewing and roasting, respectively) and 118 °C for 8 min (autoclaving). Tryptophan degradation, fluorescent oxidation products, free thiol content and α-aminoadipic and γ-glutamic semialdehydes were tracked. For all of them, there was a consistent trend to increased levels of oxidative damage with higher cooking temperatures and longer cooking times, although the extent varied from one indicator to another. Through proteomics, peptide oxidative modifications like carbonylation, malonaldehyde adducts and hydroxykynurenin (tryptophan oxidation products) were also detected at residue level. Our findings indicate that protein oxidation is dependent upon the heat treatment, which point out to a different effect on the nutritional quality of proteins in meat products.


Assuntos
Culinária , Proteômica , Carne Vermelha/análise , Animais , Temperatura Alta , Proteínas Musculares/química , Músculo Esquelético/química , Oxirredução , Proteólise , Suínos
8.
Molecules ; 23(2)2018 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-29419737

RESUMO

There is a growing market for the use of hydrolysates from animal side-streams for production of high-protein supplements. However, there can be issues with development of off-flavors, either due to the raw material in question or due to the hydrolysis process itself. This study examined the development of volatile compounds during hydrolysis of hemoglobin. Briefly, porcine hemoglobin was hydrolyzed by 0.5% papain for up to 5 h, and the development of volatile compounds was analyzed via gas chromatography-mass spectrometry. The results showed that there was significant development of a number of volatile compounds with time, e.g., certain Maillard reaction and lipid oxidation products, which are likely candidates for the aroma development during hydrolysis. Furthermore, it was shown that development of a number of the volatiles was due to the hydrolysis process, as these compounds were not found in a control without enzyme.


Assuntos
Hemoglobinas/química , Papaína/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Animais , Cromatografia Gasosa-Espectrometria de Massas , Hidrólise , Suínos
9.
Food Res Int ; 101: 266-273, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28941693

RESUMO

Structural modifications of pork proteins under an assortment of industrial heat treatments were studied. With raw as control, assorted heat treatments involved were 58, 80, 98 and 160°C for 72min, 118°C for 8min and 58°C for 17h, resembling most common processing procedures. Protein denaturation, surface protein hydrophobicity state and protein aggregation behaviour were investigated. Modifications and molecular chemistry in protein structures were tracked by Fourier Transform Infrared Spectroscopy in order to extract relative proportions of ß-sheet, α-helix and residual conformations. In comparison to uncooked samples, cooked ones showed more than two-fold increase in hydrophobicity and larger particles. Thermograms from differential scanning calorimetry showed endothermic transitions (positive enthalpy) indicating a different pattern of protein denaturation as a result of varied cooking temperatures and cooking times. Deconvolution and curve fitting procedures (R2=0.99) provided information on rise of the ß-sheet to α-helix ratio that further confirmed aggregation with thermal rise and longer cooking time.


Assuntos
Culinária , Temperatura Alta/efeitos adversos , Interações Hidrofóbicas e Hidrofílicas , Proteínas de Carne/química , Carne Vermelha/análise , Animais , Varredura Diferencial de Calorimetria , Feminino , Manipulação de Alimentos , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Desnaturação Proteica , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos , Termodinâmica
10.
Nutrients ; 9(9)2017 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-28846600

RESUMO

Low temperature long time (LTLT) sous-vide cooking may modify meat proteins in a way that could promote satiety. We investigated the effects of (1) cooking method (LTLT 58 °C vs. oven 160 °C), (2) LTLT holding time (17 h vs. 72 min), and (3) pork structure, LTLT 58 °C for 17 h (minced vs. roast) on appetite regulation and in vitro protein digestibility. In a cross-over study, 37 healthy men consumed four meals containing pork: LTLT-cooked roast, 58 °C, 72 min; LTLT-cooked roast, 58 °C, 17 h; and, oven-cooked roast, 160 °C to a core temperature of 58 °C and LTLT-cooked minced patties, 58 °C, 17 h. Ad libitum energy intake (EI) after three hours was the primary endpoint. Moreover, subjective appetite sensations were assessed. Protein digestibility was determined in an in vitro simulated digestion model. Ad libitum EI did not differ between the meals. Furthermore, appetite ratings were not clearly affected. LTLT cooking for 72 min increased the proteolytic rate in the early gastric phase during digestion as compared to LTLT cooking for 17 h or oven cooking. In conclusion, LTLT cooking, LTLT holding time, and pork structure did not affect ad libitum EI. However, LTLT cooking at 58 °C for 72 min seemed to enhance in vitro protein digestibility.


Assuntos
Culinária/métodos , Proteínas na Dieta/metabolismo , Digestão , Refeições , Produtos da Carne , Carne , Resposta de Saciedade , Adulto , Animais , Animais Endogâmicos , Regulação do Apetite , Estudos Cross-Over , Dinamarca , Ingestão de Energia , Feminino , Preferências Alimentares , Temperatura Alta , Humanos , Hibridização Genética , Masculino , Período Pós-Prandial , Sus scrofa
11.
J Sci Food Agric ; 97(15): 5211-5215, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28452152

RESUMO

BACKGROUND: In superchilling (SC), meat is kept at temperatures around 1 °C below its initial freezing point, leading to a significant increase in shelf life. This study aimed to address the oxidative changes taking place in pork loins during prolonged storage at SC temperature. Loins were stored either at chilling (CH) conditions (2-4 °C) for 4 weeks or at SC temperature (around -1 °C) for 12 weeks. RESULTS: Storage at SC temperature diminished the rate of lipid and protein oxidation and discoloration in pork loins, so that final levels of most oxidation products and instrumental color values after 12 weeks of SC storage were similar to those after 4 weeks at CH conditions. However, hexanal content peaked by the end of SC storage, pointing to a potential accumulation of compounds from lipid oxidation during SC storage. CONCLUSION: SC storage of pork slows down the rate of lipid and protein oxidation. However, accumulation of volatile compounds from lipid oxidation could be a limiting factor for shelf life. © 2017 Society of Chemical Industry.


Assuntos
Carne/análise , Músculo Esquelético/química , Animais , Temperatura Baixa , Armazenamento de Alimentos , Lipídeos/química , Oxirredução , Proteínas/química , Suínos
12.
Meat Sci ; 130: 1-6, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28342329

RESUMO

Different types of cheese powder were added to meat emulsion sausages in order to address its influence on chemical composition, volatile compounds profile and sensory properties, and its potential to reduce salt content through boosting saltiness. Addition of cheese powder to emulsion sausages modified their profile of volatile compounds. Blue cheese increased some ketones, alcohols, and esters, while brown cheese brought typical Maillard reaction compounds. Overall, addition of cheese powders to sausages enhanced the intensity of flavour traits. A mixture of hard and blue cheese powder showed the highest effect on boosting saltiness, while brown cheese powder showed the strongest umami and meat flavour boosting effect, and sausages with added blue cheese powder showed a more intense aftertaste. Hardness significantly increased due to the addition of blue cheese powder. Addition of cheese powder to emulsion sausages might be an interesting tool to boost flavour and reduce salt content in cooked sausages with no negative effect on saltiness or overall flavour.


Assuntos
Queijo , Produtos da Carne , Paladar , Compostos Orgânicos Voláteis/análise , Animais , Emulsões , Tecnologia de Alimentos , Humanos , Cloreto de Sódio na Dieta , Suínos
13.
N Biotechnol ; 35: 19-29, 2017 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-27810336

RESUMO

Umbilical cord blood (UCB) transplantation is associated with long periods of aplastic anaemia. This undesirable situation is due to the low cell dose available per unit of UCB and the immaturity of its progenitors. To overcome this, we present a cell culture strategy aimed at the expansion of the CD34+ population and the generation of granulocyte lineage-committed progenitors. Two culture products were produced after either 6 or 14days of in vitro expansion, and their characteristics compared to non-expanded UCB CD34+ controls in terms of phenotype, colony-forming activity and multilineage repopulation potential in NOD-scid IL2Rγnull mice. Both expanded cell products maintained rapid SCID repopulation activity similar to the non-expanded control, but 14-day cultured cells showed impaired long term SCID repopulation activity. The process was successfully scaled up to clinically relevant doses of 89×106 CD34+ cells committed to the granulocytic lineage and 3.9×109 neutrophil precursors in different maturation stages. Cell yields and biological properties presented by the cell product obtained after 14days in culture were superior and therefore this is proposed as the preferred production setup in a new type of dual transplant strategy to reduce aplastic periods, producing a transient repopulation before the definitive engraftment of the non-cultured UCB unit. Importantly, human telomerase reverse transcriptase activity was undetectable, c-myc expression levels were low and no genetic abnormalities were found, as determined by G-banding karyotype, further confirming the safety of the expanded product.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Sangue Fetal/citologia , Anemia Aplástica/sangue , Anemia Aplástica/etiologia , Anemia Aplástica/prevenção & controle , Animais , Antígenos CD34/sangue , Biotecnologia , Diferenciação Celular , Linhagem da Célula , Ensaio de Unidades Formadoras de Colônias , Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Feminino , Sangue Fetal/imunologia , Facilitação Imunológica de Enxerto/métodos , Granulócitos/citologia , Humanos , Subunidade gama Comum de Receptores de Interleucina/deficiência , Subunidade gama Comum de Receptores de Interleucina/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Neutrófilos/citologia
14.
Diabetes ; 65(7): 1977-1987, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26961115

RESUMO

While the autoimmune destruction of pancreatic ß-cells underlying type 1 diabetes (1D) development is ultimately mediated by T-cells in NOD mice and also likely humans, B-lymphocytes play an additional key pathogenic role. It appears expression of plasma membrane bound immunoglobulin (Ig) molecules that efficiently capture ß-cell antigens allows autoreactive B-lymphocytes bypassing normal tolerance induction processes to be the subset of antigen presenting cells most efficiently activating diabetogenic T-cells. NOD mice transgenically expressing Ig molecules recognizing antigens that are (insulin) or not (hen egg lysozyme; HEL) expressed by ß-cells have proven useful in dissecting the developmental basis of diabetogenic B-lymphocytes. However, these transgenic Ig specificities were originally selected for their ability to recognize insulin or HEL as foreign, rather than autoantigens. Thus, we generated and characterized NOD mice transgenically expressing an Ig molecule representative of a large proportion of naturally occurring islet-infiltrating B-lymphocytes in NOD mice recognizing the neuronal antigen peripherin. Transgenic peripherin autoreactive B-lymphocytes infiltrate NOD pancreatic islets, acquire an activated proliferative phenotype, and potently support accelerated T1D development. These results support the concept of neuronal autoimmunity as a pathogenic feature of T1D, and targeting such responses could ultimately provide an effective disease intervention approach.

15.
Mol Cell Endocrinol ; 426: 101-12, 2016 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-26911933

RESUMO

The transmembrane glycoprotein CD26 or dipeptidyl peptidase IV (DPPIV) is a multifunctional protein. In immune system, CD26 plays a role in T-cell function and is also involved in thymic maturation and emigration patterns. In preclinical studies, treatment with DPPIV inhibitors reduces insulitis and delays or even reverses the new -onset of type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. However, the specific mechanisms involved in these effects remain unknown. The aim of the present study was to investigate how DPPIV inhibition modifies the expression of genes in the thymus of NOD mice by microarray analysis. Changes in the gene expression of ß-cell autoantigens and Aire in thymic epithelial cells (TECs) were also evaluated by using qRT-PCR. A DPPIV inhibitor, MK626, was orally administered in the diet for 4 and 6 weeks starting at 6-8 weeks of age. Thymic glands from treated and control mice were obtained for each study checkpoint. Thymus transcriptome analysis revealed that 58 genes were significantly over-expressed in MK626-treated mice after 6 weeks of treatment. Changes in gene expression in the thymus were confined mainly to the immune system, including innate immunity, chemotaxis, antigen presentation and immunoregulation. Most of the genes are implicated in central tolerance mechanisms through several pathways. No differences were observed in the expression of Aire and ß-cell autoantigens in TECs. In the current study, we demonstrate that treatment with the DPPIV inhibitor MK626 in NOD mice alters the expression of the immune response-related genes in the thymus, especially those related to immunological central tolerance, and may contribute to the prevention of T1D.


Assuntos
Dipeptidil Peptidase 4/metabolismo , Inibidores da Dipeptidil Peptidase IV/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Indinavir/farmacologia , Animais , Apresentação do Antígeno/genética , Feminino , Regulação da Expressão Gênica/imunologia , Redes Reguladoras de Genes , Imunomodulação/genética , Camundongos Endogâmicos NOD , Timo/efeitos dos fármacos , Timo/metabolismo , Transcriptoma
16.
Eur J Immunol ; 46(3): 593-608, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26639224

RESUMO

Autoreactive B lymphocytes play a key role as APCs in diaebetogenesis. However, it remains unclear whether B-cell tolerance is compromised in NOD mice. Here, we describe a new B lymphocyte transgenic NOD mouse model, the 116C-NOD mouse, where the transgenes derive from an islet-infiltrating B lymphocyte of a (8.3-NODxNOR) F1 mouse. The 116C-NOD mouse produces clonal B lymphocytes with pancreatic islet beta cell specificity. The incidence of T1D in 116C-NOD mice is decreased in both genders when compared with NOD mice. Moreover, several immune selection mechanisms (including clonal deletion and anergy) acting on the development, phenotype, and function of autoreactive B lymphocytes during T1D development have been identified in the 116C-NOD mouse. Surprisingly, a more accurate analysis revealed that, despite their anergic phenotype, 116C B cells express some costimulatory molecules after activation, and induce a T-cell shift toward a Th17 phenotype. Furthermore, this shift on T lymphocytes seems to occur not only when both T and B cells contact, but also when helper T (Th) lineage is established. The 116C-NOD mouse model could be useful to elucidate the mechanisms involved in the generation of Th-cell lineages.


Assuntos
Linfócitos B/imunologia , Anergia Clonal , Diabetes Mellitus Tipo 1/imunologia , Modelos Animais de Doenças , Tolerância Imunológica/genética , Ativação Linfocitária , Células Th17/imunologia , Animais , Deleção Clonal , Citocinas/genética , Citocinas/imunologia , Tolerância Imunológica/imunologia , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Fenótipo , Baço/anatomia & histologia , Baço/citologia , Baço/imunologia , Transgenes
17.
Food Chem ; 194: 476-86, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26471582

RESUMO

Spray-dried microcapsules from double (DM) and multilayered (MM) fish oil emulsions were produced to evaluate the effect of type of emulsion on the fatty acid composition during the microencapsulation process and after one month of storage at refrigeration (4°C) and room (20°C) temperature. Encapsulation efficiency, loading and loading efficiency were significantly higher in MM than in DM. C20:5 n-3 (EPA) and C22:6 n-3 (DHA) showed higher proportions in MM than in DM. Some differences in microstructural features were detected, with DM showing cracks and pores. The influence of the storage was significant, decreasing the content of polyunsaturated fatty acids in both MM and DM, above all at 20°C. This decrease was more notable in DM. Multilayered emulsions are more suitable to encapsulate fish oil in terms of quantity of encapsulated oil, microstructure of the microcapsules and protection of fatty acids, especially EPA and DHA, during storage.


Assuntos
Cápsulas/química , Composição de Medicamentos/métodos , Emulsões/química , Ácidos Graxos Ômega-3/química , Óleos de Peixe/química , Animais
18.
PLoS One ; 10(11): e0142186, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26555789

RESUMO

CD26 is a T cell activation marker consisting in a type II transmembrane glycoprotein with dipeptidyl peptidase IV (DPPIV) activity in its extracellular domain. It has been described that DPPIV inhibition delays the onset of type 1 diabetes and reverses the disease in non-obese diabetic (NOD) mice. The aim of the present study was to assess the effect of MK626, a DPPIV inhibitor, in type 1 diabetes incidence and in T lymphocyte subsets at central and peripheral compartments. Pre-diabetic NOD mice were treated with MK626. Diabetes incidence, insulitis score, and phenotyping of T lymphocytes in the thymus, spleen and pancreatic lymph nodes were determined after 4 and 6 weeks of treatment, as well as alterations in the expression of genes encoding ß-cell autoantigens in the islets. The effect of MK626 was also assessed in two in vitro assays to determine proliferative and immunosuppressive effects. Results show that MK626 treatment reduces type 1 diabetes incidence and after 6 weeks of treatment reduces insulitis. No differences were observed in the percentage of T lymphocyte subsets from central and peripheral compartments between treated and control mice. MK626 increased the expression of CD26 in CD8+ T effector memory (TEM) from spleen and pancreatic lymph nodes and in CD8+ T cells from islet infiltration. CD8+TEM cells showed an increased proliferation rate and cytokine secretion in the presence of MK626. Moreover, the combination of CD8+ TEM cells and MK626 induces an immunosuppressive response. In conclusion, treatment with the DPPIV inhibitor MK626 prevents experimental type 1 diabetes in association to increase expression of CD26 in the CD8+ TEM lymphocyte subset. In vitro assays suggest an immunoregulatory role of CD8+ TEM cells that may be involved in the protection against autoimmunity to ß pancreatic islets associated to DPPIV inhibitor treatment.


Assuntos
Linfócitos T CD8-Positivos/efeitos dos fármacos , Diabetes Mellitus Tipo 1/prevenção & controle , Dipeptidil Peptidase 4/efeitos dos fármacos , Inibidores da Dipeptidil Peptidase IV/farmacologia , Fosfato de Sitagliptina/análogos & derivados , Animais , Autoantígenos/genética , Linfócitos T CD8-Positivos/imunologia , Diabetes Mellitus Tipo 1/imunologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/imunologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos NOD , Fosfato de Sitagliptina/farmacologia , Fator de Crescimento Transformador beta/sangue
19.
Food Chem ; 168: 487-95, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25172739

RESUMO

The influence of the addition of a flavour enhancer solution (FES) (d-glucose, d-ribose, l-cysteine and thiamin) and of sous-vide cooking or roasting on moisture, cooking loss, instrumental colour, sensory characteristics and formation of Maillard reaction (MR) compounds in lamb loins was studied. FES reduced cooking loss and increased water content in sous-vide samples. FES and cooking method showed a marked effect on browning development, both on the meat surface and within. FES led to tougher and chewier texture in sous-vide cooked lamb, and enhanced flavour scores of sous-vide samples more markedly than in roasted ones. FES added meat showed higher contents of furosine; 1,2-dicarbonyl compounds and 5-hydroxymethylfurfural did not reach detectable levels. N-ε-carboxymethyllysine amounts were rather low and not influenced by the studied factors. Cooked meat seems to be a minor dietary source of MR products, regardless the presence of reducing sugars and the cooking method.


Assuntos
Culinária/métodos , Aromatizantes/química , Produtos Finais de Glicação Avançada/análise , Carne/análise , Paladar , Animais , Cor , Cisteína/química , Furaldeído/análogos & derivados , Furaldeído/química , Glucose/química , Temperatura Alta , Ribose/química , Ovinos , Fatores de Tempo , Água/análise
20.
J Immunol ; 192(7): 3080-90, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24610011

RESUMO

Autoreactive B cells are essential for the pathogenesis of type 1 diabetes. The genesis and dynamics of autoreactive B cells remain unknown. In this study, we analyzed the immune response in the NOD mouse model to the neuronal protein peripherin (PRPH), a target Ag of islet-infiltrating B cells. PRPH autoreactive B cells recognized a single linear epitope of this protein, in contrast to the multiple epitope recognition commonly observed during autoreactive B cell responses. Autoantibodies to this epitope were also detected in the disease-resistant NOR and C57BL/6 strains. To specifically detect the accumulation of these B cells, we developed a novel approach, octameric peptide display, to follow the dynamics and localization of anti-PRPH B cells during disease progression. Before extended insulitis was established, anti-PRPH B cells preferentially accumulated in the peritoneum. Anti-PRPH B cells were likewise detected in C57BL/6 mice, albeit at lower frequencies. As disease unfolded in NOD mice, anti-PRPH B cells invaded the islets and increased in number at the peritoneum of diabetic but not prediabetic mice. Isotype-switched B cells were only detected in the peritoneum. Anti-PRPH B cells represent a heterogeneous population composed of both B1 and B2 subsets. In the spleen, anti-PRPH B cell were predominantly in the follicular subset. Therefore, anti-PRPH B cells represent a heterogeneous population that is generated early in life but proliferates as diabetes is established. These findings on the temporal and spatial progression of autoreactive B cells should be relevant for our understanding of B cell function in diabetes pathogenesis.


Assuntos
Linfócitos B/imunologia , Diabetes Mellitus Tipo 1/imunologia , Ilhotas Pancreáticas/imunologia , Periferinas/imunologia , Sequência de Aminoácidos , Animais , Autoanticorpos/imunologia , Autoanticorpos/metabolismo , Linfócitos B/metabolismo , Linfócitos B/patologia , Western Blotting , Linhagem Celular Tumoral , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Progressão da Doença , Mapeamento de Epitopos/métodos , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito B/metabolismo , Feminino , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Microscopia de Fluorescência , Dados de Sequência Molecular , Periferinas/genética , Periferinas/metabolismo , Peritônio/imunologia , Peritônio/metabolismo , Isoformas de Proteínas/imunologia , Baço/imunologia , Baço/metabolismo
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