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1.
Endocrinology ; 164(3)2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36423209

RESUMO

In contrast to mammals, birds have a higher basal metabolic rate and undertake wide range of energy-demanding activities. As a consequence, food deprivation for birds, even for a short period, poses major energy challenge. The energy-regulating hypothalamic homeostatic mechanisms, although extensively studied in mammals, are far from clear in the case of birds. We focus on the interplay between neuropeptide Y (NPY) and thyrotropin-releasing hormone (TRH), 2 of the most important hypothalamic signaling agents, in modulating the energy balance in a bird model, the zebra finch, Taeniopygia guttata. TRH neurons were confined to a few nuclei in the preoptic area and hypothalamus, and fibers widely distributed. The majority of TRH neurons in the hypothalamic paraventricular nucleus (PVN) whose axons terminate in median eminence were contacted by NPY-containing axons. Compared to fed animals, fasting significantly reduced body weight, PVN pro-TRH messenger RNA (mRNA) and TRH immunoreactivity, but increased NPY mRNA and NPY immunoreactivity in the infundibular nucleus (IN, avian homologue of mammalian arcuate nucleus) and PVN. Refeeding for a short duration restored PVN pro-TRH and IN NPY mRNA, and PVN NPY innervation to fed levels. Compared to control tissues, treatment of the hypothalamic superfused slices with NPY or an NPY-Y1 receptor agonist significantly reduced TRH immunoreactivity, a response blocked by treatment with a Y1-receptor antagonist. We describe a detailed neuroanatomical map of TRH-equipped elements, identify new TRH-producing neuronal groups in the avian brain, and demonstrate rapid restoration of the fasting-induced suppression of PVN TRH following refeeding. We further show that NPY via Y1 receptors may regulate PVN TRH neurons to control energy balance in T. guttata.


Assuntos
Tentilhões , Hormônio Liberador de Tireotropina , Animais , Masculino , Hormônio Liberador de Tireotropina/genética , Neuropeptídeo Y/metabolismo , Hipotálamo/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , RNA Mensageiro/metabolismo , Mamíferos/genética
2.
Colloids Surf B Biointerfaces ; 174: 569-574, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30502668

RESUMO

This study demonstrates the evaluation of ochratoxin A (OTA) in coffee on compact surface plasmon resonance (SPR) biosensors based on crosslinked chitosan and carboxymethyl chitosan nanomatrix substrates. Ochratoxin A is a toxic secondary metabolite widely produced by Aspergillus and Penicillium fungi and requires regular quantification and detection in food samples. The gold coated SPR chips were synthesized with chitosan and carboxymethyl chitosan through spin coating technique. The SPR nanomatrix chips were used for the immobilization of ochratoxin A-bovine serum albumin (OTA-BSA) conjugate to develop a competitive inhibition immunoassay. The monoclonal ochratoxin A antibodies (mAb-OTA) were used as biological receptors for the detection of OTA in buffer and coffee samples. The limit of detection (LOD) in coffee for chitosan (CS) and carboxymethyl chitosan (CMC) substrates was 5.7 ng/mL and 3.8 ng/mL, respectively. Compact surface plasmon resonance (SPR) system based on chitosan-based (CS-AU) nanomatrix substrates provides a platform for the detection of ochratoxin A with high sensitivity, accuracy, ease-of-use and cost-effectiveness. This compact SPR system can be used at farm and industrial levels for the detection of OTA in food matrices.


Assuntos
Anticorpos Monoclonais/imunologia , Carcinógenos/análise , Quitosana/química , Café/química , Contaminação de Alimentos/análise , Ocratoxinas/análise , Ressonância de Plasmônio de Superfície/métodos , Ligação Competitiva , Bioensaio , Técnicas Biossensoriais , Ocratoxinas/imunologia
3.
Front Microbiol ; 9: 2278, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30374334

RESUMO

Fermentation has been used for centuries to produce food in South-East Asia and some foods of this region are famous in the whole world. However, in the twenty first century, issues like food safety and quality must be addressed in a world changing from local business to globalization. In Western countries, the answer to these questions has been made through hygienisation, generalization of the use of starters, specialization of agriculture and use of long-distance transportation. This may have resulted in a loss in the taste and typicity of the products, in an extensive use of antibiotics and other chemicals and eventually, in a loss in the confidence of consumers to the products. The challenges awaiting fermentation in South-East Asia are thus to improve safety and quality in a sustainable system producing tasty and typical fermented products and valorising by-products. At the end of the "AsiFood Erasmus+ project" (www.asifood.org), the goal of this paper is to present and discuss these challenges as addressed by the Tropical Fermentation Network, a group of researchers from universities, research centers and companies in Asia and Europe. This paper presents current actions and prospects on hygienic, environmental, sensorial and nutritional qualities of traditional fermented food including screening of functional bacteria and starters, food safety strategies, research for new antimicrobial compounds, development of more sustainable fermentations and valorisation of by-products. A specificity of this network is also the multidisciplinary approach dealing with microbiology, food, chemical, sensorial, and genetic analyses, biotechnology, food supply chain, consumers and ethnology.

4.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-312435

RESUMO

<p><b>OBJECTIVE</b>To evaluate the presence and antibiogram pattern of Salmonella and Staphylococcus aureus (S. aureus) in retail poultry meat products.</p><p><b>METHODS</b>Foodborne pathogens (Salmonella and S. aureus) were isolated from poultry meat and confirmed with the help of biochemical and immunological test. Antibiogram of the isolates were examined by following CLSI methods.</p><p><b>RESULTS</b>A total number of 209 poultry meat samples were collected and studied in this study. Out of which, 5.26% were found contaminated with Salmonella while 18.18% were found contaminated with S. aureus. All the Salmonella and S. aureus isolates were found resistant to at least one antibiotic. About 72.72% of the Salmonella isolates showed resistance to tetracycline, while S. aureus isolates were also found highly resistant to tetracycline equal to 44.73%. One of the Salmonella isolates showed multi-drug resistance to almost six antibiotics out of nine antibiotics used in the study. Multidrug resistant S. aureus isolates were also found in the study.</p><p><b>CONCLUSIONS</b>The study confirmed the presence of Salmonella and S. aureus in retail poultry meat. It is a potential threat to consumer health. To reduce the risk of contamination, good hygiene practices are necessary from processing to storage.</p>


Assuntos
Animais , Antibacterianos , Farmacologia , Farmacorresistência Bacteriana Múltipla , Microbiologia de Alimentos , Carne , Microbiologia , Testes de Sensibilidade Microbiana , Aves Domésticas , Prevalência , Salmonella , Staphylococcus aureus , Tailândia , Epidemiologia
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