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1.
Vet Dermatol ; 34(6): 608-617, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37700614

RESUMO

BACKGROUND: Footbaths can be used to manage digital dermatitis (DD), a common cause of lameness in dairy cattle. Copper sulfate and chelated copper-zinc (CZS) solutions in footbaths are potentially harmful to the environment. HYPOTHESIS/OBJECTIVES: To determine if a quaternary ammonium salt-based disinfectant (QASD) footbath is as effective as a chelated CZS solution in controlling DD in dairy cows. ANIMALS: Fifty-one lactating Holstein cows were randomly assigned to one of two treatment groups, with DD status based on the M-stage scoring system and locomotion score balanced between treatment groups. MATERIALS AND METHODS: The groups were treated with a 1% QASD or a 2.5% chelated CZS. Footbaths were performed once per week for 15 weeks. Logistic regression was used to analyse clinical improvement. All cows received appropriate medical treatment for DD and other hoof diseases. RESULTS: Clinical improvement rates were 67% in the QASD group and 38% in the CZS group (p = 0.03). Logistic regression analysis showed that the odds (95% confidence interval) for clinical improvement rate in the CZS group were 0.30 (0.095-0.948) times that of the QASD group (p = 0.04). The M0 score in the QASD and CZS groups increased significantly (p < 0.05) at the end of the 15 week study period. In the QASD group, the proportion of M2, M3 and M4 scores were significantly decreased (p < 0.05). CONCLUSION AND CLINICAL RELEVANCE: Over a 15 week period, QASD for footbathing was associated with a lower prevalence of active DD lesions than when using CZS.


Assuntos
Compostos de Amônio , Doenças dos Bovinos , Dermatite Digital , Desinfetantes , Feminino , Animais , Bovinos , Cobre/uso terapêutico , Desinfetantes/uso terapêutico , Dermatite Digital/tratamento farmacológico , Dermatite Digital/patologia , Lactação , Taiwan , Fazendas , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/patologia , Zinco/uso terapêutico , Compostos de Amônio/uso terapêutico
2.
Vet Sci ; 10(3)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36977264

RESUMO

The transition dairy cows are challenged by various stresses such as decreased dry matter intake, liver dysfunction, increased inflammation, and oxidative stress, particularly in subtropical regions. These might increase the requirement for vitamin E and trace elements. To examine whether supplementation of vitamin E, selenium or copper, zinc, and manganese complex would help transition dairy cows to achieve greater reproduction performance by overcoming the immune function and postpartum disorders in subtropical Taiwan. A total of 24 Holstein Friesian dairy cows were enrolled in this study and divided into three groups (n = 8 cows/group): treatment 1 supplemented with organic selenium and vitamin E (SeE), treatment 2 supplemented with organic copper, zinc, and manganese complex (CZM) and control (CON). The results showed SeE supplementation improved immune function, reproductive performance, and milk yield, but not negative energy balance status. Supplementation of CZM improved milk yield and energy regulation through antioxidative capacity and immune function, but had no influence on reproductive performance.

3.
Front Microbiol ; 13: 920190, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36051771

RESUMO

The gut microbiome is essential for a host to digest food, maintain health, and adapt to environments. Bacterial communities of gut microbiota are influenced by diverse factors including host physiology and the environment. Many non-human primates (NHPs), which are physiologically close to humans, are in danger of extinction. In this study, the community structure of the gut microbiota in three NHPs: siamangs (Symphalangus syndactylus, Ss), Bornean orangutans (Pongo pygmaeus, Pp), and white-handed gibbons (Hylobates lar, Hl)-housed at the largest Zoo in Taiwan were analyzed. Pp and Ss were housed in the Asian tropical rainforest area, while Hl was housed in two separate areas, the Asian tropical rainforest area and the conservation area. Bacterial community diversity of Ss, indicated by the Shannon index, was significantly higher compared with that of Hl and Pp, while the richness (Chao 1) and observed operational taxonomic units (OTUs) were similar across the three species of NHPs. Host species was the dominant factor shaping the gut microbial community structure. Beta-diversity analysis including non-metric multidimensional scaling (NMDS) and unweighted pair group method with arithmetic mean (UPGMA) suggested gut bacterial communities of Hl housed in the conservation area were closely related to each other, while the bacterial communities of Hl in the rainforest area were dispersedly positioned. Further analysis revealed significantly higher abundances of Lactobacillus fermentum, L. murinus, and an unclassified species of Lactobacillus, and a lower abundance of Escherichia-Shigella in Hl from the conservation area relative to the rainforest area. The ratio of Lactobacillus to Escherichia-Shigella was 489.35 and 0.013 in Hl inhabiting the conservation and rainforest areas, respectively. High abundances of Lactobacillus and Bifidobacterium and a high ratio of Lactobacillus to Escherichia-Shigella were also observed in one siamang with notable longevity of 53 years. Data from the study reveal that host species acted as the fundamental driving factor in modulating the community structure of gut microbiota, but that habitats also acted as key determinants within species. The presence and high abundance of probiotics, such as Bifidobacterium and Lactobacillus, provide potential indicators for future diet and habitat optimization for NHPs, especially in zoological settings.

4.
Mar Pollut Bull ; 182: 113989, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35939929

RESUMO

To investigate the impacts of sub-lethal concentrations of antibiotic agents in mariculture, culturable approach and DNA based detection were employed to isolate and analyse resistant bacteria and resistant genes in this study. Milkfish (Chanos chanos), the target rearing animal was exposed to sulfamethoxazole (SMX; 2 mg/L) for 8 weeks and resulted in reduced survival rate and weight gain to 61.9 % and 28.4 %, respectively compared to control milkfish (p < 0.001). The composition of SMX-resistant bacteria isolated from the culture water and the gastrointestinal tracts of milkfish underwent changes in response to SMX treatment with a reduced diversity. The prevalence of SMX resistant genes sul in bacterial isolates was elevated from 2.8 % of control to 100 % of SMX-administrated water. Exposure to SMX at a sub-lethal dosage enhanced the prevalence of resistance genes sul1 and sul2 in resistant bacteria, thus implying high frequency of resistance dissemination in the marine environment and surrounding ecosystems.


Assuntos
Antibacterianos , Sulfametoxazol , Animais , Bactérias , Ecossistema , Peixes , Prevalência , Sulfonamidas , Água
5.
J Anim Sci ; 100(10)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35985291

RESUMO

Infrared thermography (IRT) can measure a temperature change on the surface of objects, and is widely used as an inflammation or fever detection tool. The objective of this longitudinal study was to investigate the feasibility of detecting hoof lesion cattle using IRT under subtropical climate conditions. The experiment was conducted in two free-stall commercial dairy farms and 502 dairy cows participated between August 2020 and March 2022. Before hoof trimming, the portable IRT was used to measure the maximum temperature of each hoof from three shooting directions, including anterior (hoof coronary band), lateral (hoof lateral coronary band), and posterior (skin between heel and bulbs). In order to evaluate the effect of hoof lesions on the behavior of dairy cows, we also collected behavior data by automated accelerometers. The results indicated that the temperature of hooves with lesions was significantly higher than that of sound hooves in hot environments regardless of the shooting directions (P < 0.0001). In all of three shooting directions, the maximum temperature of feet with severe lesion was significantly higher than those of feet with mild lesion and sound feet (P < 0.05). Cows with lesion feet had lower daily activity and feeding time than sound cows before clinical diagnosis (P < 0.05). Furthermore, we used thresholds of both anterior hoof temperature at 32.05 °C and average daily activity at 410.5 (arbitrary unit/d) as a lame cow detecting tool. The agreement of this integrated tool reached 75% with clinical diagnosis, indicating that this integrated approach may be feasible for practice in dairy farm. In conclusion, IRT has the potential to be used as a hoof lesion detecting tool under subtropical climate conditions when using sound hoof temperature as reference points, and detection precision can be improved when IRT integrated with automated accelerometers as a lame cow detecting tool.


Infrared thermography (IRT) has been considered as one of the most effective tools for identification of hoof lesions in dairy cows. However, ambient temperature had been proven to affect the measurement of the IRT. The purpose of this current study is to investigate whether IRT could detect changes in hoof temperature on the feet with lesions under subtropical climate conditions. The results indicated that the maximum temperature of affected hoof was significantly higher than that of nonaffected hoof even in hot environments. The diagnostic accuracy of the IRT could be above 70%. When combining daily activity value collected by accelerometer of each cow with hoof temperature as a hoof lesion detected criterion, the accuracy of this integrated diagnostic tool could elevate to 75%. This suggests that IRT can be used as a hoof lesion detecting tool under subtropical climate conditions.


Assuntos
Doenças dos Bovinos , Doenças do Pé , Casco e Garras , Feminino , Bovinos , Animais , Casco e Garras/patologia , Termografia/veterinária , Termografia/métodos , Estudos Longitudinais , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/patologia , Doenças do Pé/diagnóstico , Doenças do Pé/veterinária , Acelerometria/veterinária
6.
Toxins (Basel) ; 11(6)2019 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-31181798

RESUMO

Zearalenone (ZEN) is an estrogenic mycotoxin which can cause loss in animal production. The aim of this study was to screen Bacillus strains for their ZEN detoxification capability and use a fermentation process to validate their potential application in the feed industry. In the high-level ZEN-contaminated maize (5 mg·kg-1) fermentation test, B2 strain exhibited the highest detoxification rate, removing 56% of the ZEN. However, B2 strain was not the strain with the highest ZEN detoxification in the culturing media. When B2 grew in TSB medium with ZEN, it had higher bacterial numbers, lactic acid, acetic acid, total volatile fatty acids, and ammonia nitrogen. The ZEN-contaminated maize fermented by B2 strain had better fermentation characteristics (lactic acid > 110 mmol·L-1; acetic acid < 20 mmol·L-1; pH < 4.5) than ZEN-free maize. Furthermore, B2 also had detoxification capabilities toward aflatoxins B1, deoxynivalenol, fumonisin B1, and T2 toxin. Our study demonstrated differences in screening outcome between bacterial culturing conditions and the maize fermentation process. This is important for the feed industry to consider when choosing a proper method to screen candidate isolates for the pretreatment of ZEN-contaminated maize. It appears that using the fermentation process to address the ZEN-contaminated maize problem in animal feed is a reliable choice.


Assuntos
Bacillus/metabolismo , Contaminação de Alimentos/prevenção & controle , Zea mays/microbiologia , Zearalenona/metabolismo , Ração Animal , Animais , Bacillus/genética , Bacillus/isolamento & purificação , Fezes/microbiologia , Fermentação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Rúmen/microbiologia , Ruminantes , Microbiologia do Solo , /microbiologia
7.
Sci Total Environ ; 643: 681-691, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29957433

RESUMO

Aquaculture, one of the most important food production practices worldwide, faces serious challenges of mitigating the detrimental impacts of intensive farming on the environment and increased prevalence of antibiotic resistance. To develop an environment-friendly aquaculture system, a land-based and farm-scale sequentially integrated multi-trophic aquaculture (IMTA) system was established for farming Chanos chanos in southwestern Taiwan. In this system, fishes are cultured in combination with organic extractive shellfish and inorganic extractive seaweed. This study aimed to evaluate the prevalence of sulfonamide-resistant bacteria, microbial community structure, and occurrence of sulfonamide resistance genes in the IMTA and traditional aquaculture systems. Water and sediment samples were collected before raising and after harvesting C. chanos. Our results showed that the occurrence of sulfonamide-resistant phenotypes in the IMTA system was comparable with that in influent seawater, while the traditional system exhibited a high sulfonamide resistance rate. Additionally, the traditional system resulted in a deviation of the bacterial community structure from that of seawater. In the water samples from the IMTA system and influent seawater, Proteobacteria and Bacteroidetes were the two dominant phyla, representing approximately 75% and 15% of the community, respectively. In the traditional system, Actinobacteria, constituting 39% of the community, was the dominant bacterial phylum. Thirty-one sulfonamide-resistant bacterial species were isolated. In conclusion, a sequentially IMTA system showed superior ability to maintain the prevalence of antibiotic resistance and the integrity of the bacterial community structure compared to the traditional farming system, representing a potentially valuable aquaculture system for preserving the sustainability of the marine environment.


Assuntos
Aquicultura , Farmacorresistência Bacteriana/genética , Monitoramento Ambiental , Microbiologia da Água , Animais , Bactérias , Fazendas , Genes Bacterianos , Prevalência , Sulfonamidas/análise , Taiwan
8.
J Sci Food Agric ; 98(10): 3870-3879, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29364505

RESUMO

BACKGROUND: Zearalenone (ZEA) is an estrogenic mycotoxin produced by several Fusarium species and frequently contaminates cereals used for food or animal feed. This study attempted to select lactic acid bacteria (LAB) with high esterase activity from the digestive tract, with the goal of using these bacteria for ZEA detoxification. RESULTS: No ZEA activity-related biotransformation products were observed in three isolates (B1, B2 and D10) during incubation in the presence of ZEA. All three LAB strains were Lactobacillus plantarum, but the API 50 CHL results suggested that the three isolates were different strains. Increased esterase activity was associated with an increase in cell growth, and the ZEA-detoxifying capabilities of isolates rely on the concentration of bacteria in the culture medium. The lipolytic activity and ZEA removal assay indicated that ZEA degradation by the supernatant fraction was dependent on esterase activity; the supernatant of B2 strain showed the highest ZEA degradation ability and did not release the binding ZEA back into the medium. The D10 strain showed fast ZEA binding ability during the late log phase but began to release the bound ZEA back into the medium after the early stationary phase. All isolates showed good acid and bile salt tolerance ability but all strains showed low adhesion ability to epithelial cells. CONCLUSION: Based on the ZEA removal characterization and ability of the isolates, it is suggested that the isolates could be applied to ZEA detoxification of contaminated feed, but the with the requirement of high cell number for ZEA binding and limited degradation time before absorption of ZEA in the digestive tract. © 2018 Society of Chemical Industry.


Assuntos
Proteínas de Bactérias/química , Esterases/química , Trato Gastrointestinal/microbiologia , Lactobacillus plantarum/enzimologia , Zearalenona/metabolismo , Ração Animal/análise , Proteínas de Bactérias/metabolismo , Biotransformação , Esterases/metabolismo , Fusarium/metabolismo , Lactobacillus plantarum/isolamento & purificação , Lactobacillus plantarum/metabolismo , Zearalenona/química
9.
Food Funct ; 6(8): 2727-35, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26147740

RESUMO

BACKGROUND: This study investigated the effect of yeast with bacteriocin (YB) on the homeostasis of lipid and glucose in diet-induced obese (DIO) mice. Seven-week-old C57BL/6 male mice were fed with a Western diet for 24 weeks to induce obesity. These DIO mice were randomly assigned to 2 groups: obese control (WS) and WYB [0.125 µg YB per g body weight (BW)]. YB was administered daily to the WYB mice in the last 4 weeks, while an equal volume of normal saline was administered to the WS mice. RESULTS: YB caused a significant reduction in BW, and in plasma levels of total cholesterol and glucose. Less hepatic lipid accumulation and smaller adipocytes were observed in WYB mice. WYB mice had higher lipid catabolism in liver and adipose tissue. Compared with WS mice, WYB mice had higher glycolysis in the liver and muscles. YB suppressed hepatic GLUT5 expression, altered the composition of cecal microbiota, and also caused more efficient carbohydrate utilization for energy expenditure. CONCLUSION: YB resulted in body weight loss, promoted lipid catabolism and carbohydrate utilization; it also modulated cecal microbiota, and therefore partially improved the health of obese mice.


Assuntos
Bacteriocinas/administração & dosagem , Ceco/microbiologia , Gorduras/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Glucose/metabolismo , Obesidade/tratamento farmacológico , Tecido Adiposo/metabolismo , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bacteriocinas/genética , Bacteriocinas/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/metabolismo , Obesidade/microbiologia , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
10.
J Hazard Mater ; 277: 34-43, 2014 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-24637153

RESUMO

Antibiotics are commonly used in swine feed to treat and prevent disease, as well as to promote growth. Antibiotics released into the environment via wastewater could accelerate the emergence of antibiotic-resistant bacteria and resistance genes in the surrounding environment. In this study, we quantified the occurrence of sulfonamides, sulfonamide-resistant microorganisms and resistance genes in the wastewater from a swine farm in northern Taiwan and its surrounding natural water bodies and soils. Sulfonamide levels were similar in the receiving downstream and upstream river water. However, the prevalence of sulfonamide-resistant bacteria and resistance genes, as analyzed by cultivation-dependent and -independent molecular approaches, was significantly greater in the downstream compared to the upstream river water samples. Barcoded-pyrosequencing revealed a highly diverse bacterial community structure in each sample. However, the sequence identity of the sulfonamide resistance gene sul1 in the wastewater and downstream environment samples was nearly identical (99-100%). The sul1 gene, which is genetically linked to class 1 integrons, was dominant in the downstream water bodies and soils. In conclusion, the increased prevalence of sulfonamide resistance genes in the wastewater from a swine farm, independent of the persistent presence of sulfonamides, could be a potential source of resistant gene pools in the surrounding environment.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Transferência Genética Horizontal/efeitos dos fármacos , Genes Bacterianos , Integrons/genética , Esterco/microbiologia , Microbiologia do Solo , Sulfonamidas/farmacologia , Microbiologia da Água , Animais , Integrons/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Filogenia , Microbiologia do Solo/normas , Sus scrofa , Taiwan , Microbiologia da Água/normas
11.
J Sci Food Agric ; 93(11): 2758-64, 2013 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-23553112

RESUMO

BACKGROUND: Albusin B (bacteriocin), isolated from Ruminococcus albus 7 and mass-produced by the Saccharomyces cerevisiae expression system, has previously been shown to have a beneficial effect on lipid metabolism in broiler chickens. The present study was focused on the effect of albusin B on lipid metabolism in mice and the potential of albusin B-expressing yeast product (albusin B) as a food supplement. Forty-five BALB/c male mice at 6 weeks of age were each orally administered normal saline (control), yeast (0.125 mg kg(-1) ) or albusin B (0.125 mg kg(-1) ) for 14 days and then euthanised. RESULTS: Compared with the control group, albusin B-fed mice exhibited decreased body weight and plasma levels of triglycerides and free fatty acids but increased plasma high-density lipoprotein. Albusin B-fed mice showed higher mRNA expression of fatty acid oxidation in the ileum, heart and liver than control mice. Compared with the control treatment, both yeast and albusin B treatments caused a decrease in mRNA expression of fatty acid synthesis in the heart and liver. Moreover, albusin B suppressed mRNA levels of lipogenesis in the ileum and liver. Albusin B-fed mice exhibited more favourable adenosine triphosphate production and antioxidant capacity in the heart and liver. Albusin B treatment led to a significantly lower respiratory quotient than that of the control, whereas yeast treatment did not. CONCLUSION: This study demonstrated a beneficial effect of albusin B on lipid utilisation and anti-atherosclerotic and antioxidant capacities in mice. However, more comprehensive studies are required to elucidate the exact mechanism behind the effect of albusin B.


Assuntos
Antioxidantes/metabolismo , Bacteriocinas/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Administração Oral , Animais , Bacteriocinas/química , Bacteriocinas/metabolismo , Metabolismo Basal , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Aleatória , Saccharomyces cerevisiae
12.
Anim Biotechnol ; 24(2): 129-47, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23534959

RESUMO

Lysostaphin (LYS) is an anti-staphylococcal prokaryotic polypeptide that has been used to avoid Staphylococcus aureus mastitis through transgenic or viral vector approaches exogenously expressed in dairy animals. However, glycosylation of lysostaphin expressed in mammalian cells results in a loss of bioactivity. Until now, the mechanism of site-specific glycosylation of lysostaphin causing this loss of bioactivity remains unknown. An immortalized caprine mammary epithelial cell line (CMEC-08-D) was used to study recombinant lysostaphin fused with goat ß-casein, goat lactoferrin (LF) or prokaryotic signal peptides. These constructs were separately ectopically expressed in CMEC-08-D. Results of site-directed mutagenesis show that Asn(125) but not Asn(232) is the exact glycosylation site of lysostaphin expressed in CMEC-08-D. In addition, the effect of glycosylation of lysostaphin on its staphylolytic activity was identified through bacterial plate assay. The data indicated that wild type and mutated N232Q-lysostaphin (Asn(232) to Gln(232) substitution) lacked staphylolytic activity. In contrast, mutated N125Q (Asn(125) to Gln(125) substitution) and N125Q/N232Q-lysostaphin possessed staphylolytic activity. On the other hand, all mutated lysostaphin showed no change in binding ability to S. aureus. This reveals that N-glycosylation at Asn(125) of lysostaphin expressed in a eukaryotic system greatly decreases lysostaphin bacteriolytic activity but does not affect its binding ability to S. aureus.


Assuntos
Doenças das Cabras/microbiologia , Lisostafina/farmacologia , Mastite/veterinária , Proteínas Recombinantes/farmacologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Animais , Caseínas/genética , Caseínas/metabolismo , Linhagem Celular , Clonagem Molecular , Contagem de Colônia Microbiana/veterinária , Feminino , Glicosilação , Doenças das Cabras/tratamento farmacológico , Cabras , Imuno-Histoquímica/veterinária , Lactoferrina/genética , Lactoferrina/metabolismo , Lisostafina/metabolismo , Mastite/tratamento farmacológico , Mastite/microbiologia , Mutagênese Sítio-Dirigida/veterinária , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento
13.
Biosci Biotechnol Biochem ; 76(1): 34-41, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22232237

RESUMO

The characteristics of a bacteriocin from Ruminococcus albus 7 and its potential as an antibiotic alternative were examined in this study. The addition of 3 µM 3-phenylpropanoic acid (PPA) and 0.2% Tween 80 to the culturing medium improved bacteriocin production by 2.5-fold. Native polyacrylamide gel electrophoresis of the antagonistically active gel filtration fraction established that the molecular weight of the R. albus 7 bacteriocin was approximately 36 kDa. The bacteriocin was sensitive to pepsin, protease, and pancreatin, and was inactivated by heating at 65 °C for 1 h. Simulating in vitro avian digestion decreased the antagonistic activity by 74.7%, but the addition of 1% bovin serum albumin restored 13% of the lost antagonistic activity. Following ion-exchange purification, the bacteriocin had sufficient antagonistic activity against five tested pathogenic strains, but the addition of a protectant is necessary for utilization of bacteriocin of R. albus 7 as an antibiotic alternative in animal feed.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Bacteriocinas/biossíntese , Bacteriocinas/farmacologia , Ruminococcus/metabolismo , Sequência de Aminoácidos , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Bacteriocinas/química , Bacteriocinas/metabolismo , Bovinos , Cinética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Estabilidade Proteica , Proteólise , Segurança
14.
Endocrine ; 31(1): 44-51, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17709897

RESUMO

Estrogens have been suggested to exhibit neuroprotective activities against several insults including beta-amyloid and glutamate, one of the excitatory neurotransmitters in the central nervous system. In the present study, we showed that exposure to glutamate not only inhibited the cell growth of exponentially growing rat pheochromocytoma PC12 cells in a time- and dose-dependent manner, but also influenced cell adherence capacity. Glutamate-induced growth inhibition was significantly attenuated by the co-administration of estradiol in PC12 cells. Pre-exposure of the PC12 cells to the estradiol was not required for protection against glutamate-induced growth inhibition. Administration of anti-estrogen ICI182,780 efficiently blocked the neuroprotective effects of estradiol. Glutamate-induced changes in cell adherence, on the other hand, were not significantly affected by estradiol. These data indicate that the neuroprotective effects of estradiol against glutamate-induced insults in PC12 cells, at least in part, involve estrogen receptor-dependent pathways.


Assuntos
Estradiol/fisiologia , Ácido Glutâmico/fisiologia , Sistema Nervoso/crescimento & desenvolvimento , Receptores de Estrogênio/fisiologia , Animais , Células PC12 , Ratos , Transdução de Sinais/fisiologia
15.
Anaerobe ; 11(3): 155-62, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16701546

RESUMO

In this study, Prevotella ruminicola 23 (ATCC 19189), a ruminal proteolytic bacterium, was used as protease producer to examine the optimal condition for protease production. The best carbon and nitrogen sources for the maximum growth were glucose with peptone. Both sucrose and glucose could stimulate high protease production. Casein and peptone are better nitrogen sources for protease production than other choice in this study. The best enzyme production condition was 18-20 h incubation which was at late log phase in the broth of 5% glucose or sucrose as carbon source with 0.1% ammonium chloride and 0.2% peptone as nitrogen sources. Most of the protease activity was secreted into broth (65%) and on cell surface (18%). The optimal temperature and pH for protease reaction were 40 degrees C and pH 6.8, respectively. After incubation for 6h, the crude extract maintained 50% of original protease activity at 30 and 50 degrees C, and protease activity was stable between pH 6 and 8. The protease inhibitor test showed that serine, aspartic acid and metallo-protease inhibitors could cause inhibition of proteolysis. Protein feedstuff degradation experiments suggested that protease in crude extract had higher degradation ability on fish meal, whey, and feather meal (2.39, 2.60 and 1.76 micromol aminoacid/mg enzyme/h) in comparison to soybean meal and blood meal (1.11 and 1.09 micromol aminoacid/mg enzyme/h). The protease in the crude extract should have application potential in term of improving utilization of fish meal and feather meal for monogastric animals.

16.
FEMS Microbiol Lett ; 217(1): 51-5, 2002 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-12445645

RESUMO

Methane represents a loss of feed energy to ruminant animals, and nutritionists have sought methods of inhibiting ruminal methane production. When mixed ruminal bacteria (approximately 400 mg protein ml(-1)) from a cow fed timothy hay were incubated in vitro with carbon dioxide and hydrogen (0.5 atm) for less than 8 h, the first-order rate of methane production was 17 micromol ml(-1). Semi-purified bacteriocin from Streptococcus bovis HC5 (bovicin HC5) inhibited methane production, by as much as 50%, and even a low concentration of bovicin HC5 (128 activity units (AU) ml(-1)) caused a significant decrease. Mixed ruminal bacteria that were transferred successively retained their ability to produce methane from carbon dioxide and hydrogen, and the first-order rate of methane production did not decrease. Cultures that were treated with bovicin HC5 (128 AU ml(-1)) gradually lost their ability to produce methane, and methane was not detected after four transfers. These latter results indicated that ruminal methanogens could not adapt and become resistant to bovicin HC5. When the chromosomal DNA was amplified with 16S rDNA primers specific to archaea, digested with restriction enzymes (HhaI and HaeIII) and separated on agarose gels, approximately 12 fragments were observed. DNA from control and treated cultures (third transfer) had the same fragment pattern indicating bovicin HC5 was not selective. Given the perception that the routine use of antibiotics in animal feeds should be avoided, bacteriocins may provide an alternative strategy for decreasing ruminal methane production.


Assuntos
Bacteriocinas/farmacologia , Bovinos/metabolismo , Metano/metabolismo , Streptococcus bovis , Animais , Bacteriocinas/biossíntese , Bacteriocinas/classificação , RNA Ribossômico 16S/análise , Rúmen/microbiologia , Streptococcus bovis/classificação , Streptococcus bovis/genética , Streptococcus bovis/metabolismo
17.
Reprod Nutr Dev ; 42(1): 55-64, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12199376

RESUMO

The isoflavones daidzein and biochanin A induced a biphasic growth response in T-47D human breast cancer cells. At growth stimulatory concentrations, daidzein increased the percentage of cells entering the S phase, while at a growth inhibitory concentration, daidzein obstructed the progression of the cell cycle in the G2/M phase. Biochanin A regulated the cell cycle progression in a similar manner and showed a delay in the progression from the S phase to the G2/M phase at growth inhibitory concentrations. The levels of a cell cycle regulatory protein, P53, in response to the treatment of isoflavones, were also determined. Cells that became de-attached and floated in the medium after treatment with growth inhibitory concentrations of daidzein or biochanin A, showed higher P53 levels than cells that remained attached. These results suggest that daidzein and biochanin A influence T-47D cell proliferation and cell cycle progression, and that the underlying mechanisms might be associated with the P53 protein levels.


Assuntos
Anticarcinógenos/farmacologia , Ciclo Celular/efeitos dos fármacos , Genisteína/farmacologia , Isoflavonas/farmacologia , Mitose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Carcinoma/tratamento farmacológico , Fase G2 , Humanos , Fase S , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo
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