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1.
Int J Nanomedicine ; 14: 8361-8378, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31749615

RESUMO

Purpose: This study aimed to evaluate the anti-colitis potential of platinum nanoparticles (PtNPs). Materials and methods: 5-, 30- and 70-nm PtNPs were administered to C57BL/6 mice once daily by intragastric gavage for 8 d during and after 5-d dextran sodium sulfate treatment. Results: According to body weight change, stool blood and consistency, and colon length and histopathology, PtNPs size-dependently alleviated DSS-induced murine colitis. PtNPs enhanced gut-barrier function by upregulating the colonic expressions of heat-shock protein 25 and tight junction proteins. Based on colonic myeloperoxidase activity, colonic and peripheral levels of interleukin-6 and tumor necrosis factor-α, and peripheral counts of white blood cells, PtNPs attenuated colonic and systemic inflammation. By suppressing lipopolysaccharide-triggered production of proinflammatory mediators, including nitric oxide, tumor necrosis factor-α and interleukin-6, PtNPs exerted direct anti-inflammatory activities in RAW264.7 macrophages through a mechanism involving intracellular reactive oxygen species scavenging and Toll-like receptor 4/NF-κB signaling suppression. High-throughput 16S rRNA sequencing of fecal samples unveiled that PtNPs induced gut dysbiosis by unfavorably altering α-diversity, Firmicutes/Bacteroidetes ratio, and richness of certain specific bacteria. Conclusion: PtNPs are a promising anti-colitis agent, but may negatively impact gut-microbiota.

2.
Food Funct ; 10(10): 6666-6674, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31556905

RESUMO

Animal protein intake appears to exert beneficial effects on bone health. Here, animal protein hydrolysates (APHs) originated from casein, whey protein isolate, egg white, myofibrillar protein, sarcoplasmic protein and gelatin were shown to prevent calcium phosphate (CaP) precipitation by increasing the surface charge and slowing the crystal growth of CaP particles. Dynamic light scattering, transmission electron microscopy and energy-dispersive X-ray analysis revealed the APH-mediated formation of irregularly shaped secondary nanoparticles aggregated from rather small amorphous CaP nanoclusters. APHs effectively counteracted the detrimental effect of the low calcium-to-phosphorus ratio on calcium transportation across ligated murine ileum, and by treating with NaN3, amiloride and low temperature, macropinocytosis was found to involve the intestinal uptake of CaP nanoparticles. APHs of meat origin had weaker potential to increase CaP solubility and ileal calcium transportation than those of dairy and egg origins. Overall, our study reports a novel mechanism for animal protein intake to promote intestinal calcium absorption.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31017521

RESUMO

Gold nanoparticles (AuNPs) have been previously shown to induce gut dysbiosis during colitis in mice, but the underlying mechanism is not clear yet. Here, we evaluated the effects of AuNPs (5 nm diameter, coated with tannic acid, polyvinylpyrrolidone or citrate) on H2O2 accumulation and pathogen antagonization by an intestinal strain of Lactobacillus gasseri under aerobic cultural conditions. AuNPs (0.65 µg/mL) reduced over 50% of H2O2 accumulation by L. gasseri, and significantly inhibited the antagonistic action of L. gasseri on growth of four foodborne enteric pathogens, i.e. Salmonella enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus in associative cultures.

4.
Food Funct ; 10(2): 1007-1016, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30706920

RESUMO

Biogenic polyphosphate nanoparticles (BPNPs) from Synechococcus sp. PCC 7002 have been found to exhibit intestinal protective potential in vitro and ex vivo. The aim of this study was to evaluate the in vivo intestinal protective effect of BPNPs in experimental colitis. BPNPs were intragastrically administered to C57BL/6 mice daily for 9 d during and after 5 d dextran sodium sulfate (DSS) exposure. Based on the body weight, disease activity index, colon length and colon histology, BPNPs effectively ameliorated DSS-induced colitis in mice. According to colonic myeloperoxidase activity, colonic and peripheral proinflammatory cytokines, and hematological parameters, BPNPs alleviated the DSS-induced colonic and systemic inflammation. BPNPs enhanced the intestinal barrier function by upregulating the colonic expressions of heat shock protein 25 and tight junction proteins. By high-throughput sequencing of fecal 16S rRNA, BPNPs were found to maintain gut microbial homeostasis in colitis mice. Overall, BPNPs have a considerable in vivo efficacy to maintain gut health.


Assuntos
Colite/induzido quimicamente , Colite/tratamento farmacológico , Nanopartículas/administração & dosagem , Polifosfatos/farmacologia , Synechococcus/classificação , Animais , Sulfato de Dextrana/toxicidade , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Polifosfatos/química
5.
J Nanobiotechnology ; 16(1): 86, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30384844

RESUMO

BACKGROUND: Gold nanoparticles (AuNPs) are attracting interest as potential therapeutic agents to treat inflammatory diseases, but their anti-inflammatory mechanism of action is not clear yet. In addition, the effect of orally administered AuNPs on gut microbiota has been overlooked so far. Here, we evaluated the therapeutic and gut microbiota-modulating effects, as well as the anti-inflammatory paradigm, of AuNPs with three different coatings and five difference sizes in experimental mouse colitis and RAW264.7 macrophages. RESULTS: Citrate- and polyvinylpyrrolidone (PVP)-stabilized 5-nm AuNPs (Au-5 nm/Citrate and Au-5 nm/PVP) and tannic acid (TA)-stabilized 5-, 10-, 15-, 30- and 60-nm AuNPs were intragastrically administered to C57BL/6 mice daily for 8 days during and after 5-day dextran sodium sulfate exposure. Clinical signs and colon histopathology revealed more marked anti-colitis effects by oral administration of Au-5 nm/Citrate and Au-5 nm/PVP, when compared to TA-stabilized AuNPs. Based on colonic myeloperoxidase activity, colonic and peripheral levels of interleukin-6 and tumor necrosis factor-α, and peripheral counts of leukocyte and lymphocyte, Au-5 nm/Citrate and Au-5 nm/PVP attenuated colonic and systemic inflammation more effectively than TA-stabilized AuNPs. High-throughput sequencing of fecal 16S rRNA indicated that AuNPs could induce gut dysbiosis in mice by decreasing the α-diversity, the Firmicutes/Bacteroidetes ratio, certain short-chain fatty acid-producing bacteria and Lactobacillus. Based on in vitro studies using RAW264.7 cells and electron spin resonance oximetry, AuNPs inhibited lipopolysaccharide (LPS)-triggered inducible nitric oxide (NO) synthase expression and NO production via reduction of Toll-like receptor 4 (TLR4), and attenuated LPS-induced nuclear factor kappa beta activation and proinflammatory cytokine production via both TLR4 reduction and catalytic detoxification of peroxynitrite and hydrogen peroxide. CONCLUSIONS: AuNPs have promising potential as anti-inflammatory agents; however, their therapeutic applications via the oral route may have a negative impact on the gut microbiota.

6.
Food Sci Nutr ; 6(4): 1023-1031, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29983966

RESUMO

Gelatin is an anti-inflammatory dietary component, and its predominant metabolites entering circulation are prolyl-hydroxyproline (Pro-Hyp) and glycine. We evaluated the protective effects of orally administered gelatin, glycine, and Pro-Hyp 10:3:0.8 (w/w/w) against dextran sodium sulfate (DSS)-induced colitis in mice. According to clinical, histological, and biochemical parameters, they exhibited significant activities in the order of gelatin < glycine < Pro-Hyp. Gelatin prevented the DSS-induced increase in interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the colon, rather than in peripheral blood. Glycine and Pro-Hyp attenuated the DSS-induced rise in colonic IL-6 and TNF-α, as well as peripheral IL-1ß, IL-6, and TNF-α. Hematologic results show the attenuation of DSS-induced leukocytosis and lymphocytosis by glycine and Pro-Hyp, rather than gelatin. These findings suggest that glycine and Pro-Hyp constitute the material basis for gelatin's anticolitis efficacy, and they have better anticolitis activities and distinct mechanisms of action when ingested as free compounds than as part of gelatin.

7.
J Food Sci Technol ; 55(5): 1903-1912, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29666543

RESUMO

Shewanella baltica and Acinetobacter are among the predominant spoilage bacteria in refrigerated shrimp (Litopenaeus vannamei). S. baltica are incapable of producing acyl-homoserine lactone (AHL) quorum sensing signals, but can respond to environmental AHLs. In this paper, Acinetobacter was found to produce three AHLs, i.e. N-butanoyl-l-homoserine lactone (C4-HSL), N-(3-oxohexanoyl)-l-homoserine lactone (O-C6-HSL) and N-(3-oxooctanoyl)-l-homoserine lactone (O-C8-HSL), according to thin-layer chromatography using the bioreporter Agrobacterium tumefaciens A136. The agar diffusion and ß-galactosidase assays revealed that S. baltica could eavesdrop on these three AHLs from Acinetobacter. Eavesdropping on Acinetobacter AHLs especially C4-HSL was found to boost the growth of S. baltica particularly under nutrient limiting conditions (up to 40-fold increase) in the co-culture experiments. The azocasein assay revealed that S. baltica produced fourfold more extracellular proteases in response to Acinetobacter AHLs. As demonstrated by the biofilm crystal violet staining assay and confocal laser scanning microscopy, eavesdropping also decreased the biofilm-forming capacity of Acinetobacter. By inoculation of S. baltica and Acinetobacter onto surface-sterilized shrimp, eavesdropping was found to endow a growth advantage to S. baltica in vivo, resulting in a 0.5 day shortened shelf life of shrimp according to total volatile basic nitrogen levels and sensory analysis. Overall, the AHL-dependent eavesdropping increased the spoilage potential of S. baltica, providing a fresh perspective on the spoilage process of refrigerated L. vannamei, and this may inspire the development of novel preservation techniques in the future to further reduce post-harvest loss of shrimp.

8.
Sci Rep ; 7(1): 7863, 2017 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-28801637

RESUMO

Previous studies have shown that GOLPH3 mediates cell growth, proliferation and differentiation and inhibits cell apoptosis; however, the role of GOLPH3 in cumulus granulosa cells and the value of GOLPH3 in predicting ICSI pregnancy outcomes remain unknown until now. Our findings showed higher positive expression rate, score of staining intensity, and immunohistochemical score of GOLPH3 in the cumulus granulosa cells of the pregnant women relative to non-pregnant women, and a higher apoptotic rate of cumulus granulosa cells was detected in non-pregnant women than in pregnant women. Pearson correlation analyses revealed that pregnancy correlated negatively with GOLPH3 expression and apoptosis of cumulus granulosa cells, and positively with the number of follicles punctured, number of grade III oocytes, number of eggs retrieved for ICSI, number of zygotes, number of cleavage-stage embryos, number of top-quality embryos, number of blastocysts, number of top-quality blastocysts, and number of frozen embryos. GOLPH3 may be involved in the apoptosis of cumulus granulosa cells, which may correlate with oocyte maturation and egg development. GOLPH3 expression in cumulus granulosa cells may facilitate the selection of top-quality eggs and embryos, the prediction of the clinical pregnancy outcomes of ICSI, and the increase of the pregnancy rate.

9.
J Food Sci ; 81(11): M2776-M2784, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27699803

RESUMO

Fish skin has both positive and negative effects on the shelf-life of the fish. This study aimed to investigate the spoilage process of the skin and flesh of refrigerated farmed turbot (Scophthalmus maximus) with vacuum packaging. Microbial community changes were analyzed by combining culture-dependent and culture-independent methods. The results indicated that the shelf-life of vacuum-packaged refrigerated turbot was 16 d; skin mucus was the interference factor of turbot quality. The culture-dependent analysis demonstrated that the total viable counts and the population of H2 S-producing bacteria, Pseudomonas spp., Enterobacteriaceae spp., and lactic acid bacteria in skin had a range of 0.45 to 1.40 log (CFU/g) higher than the microbial numbers in flesh after 16 d in storage. 16S high throughout sequencing results demonstrated that the compositions of spoilage microbes were similar in skin and flesh. Shewanella spp., followed by Carnobacterium spp., was the dominant spoilage organism at day 16. Quorum sensing (QS) signaling activity increased during the storage. Exogenous N-butanoyl-L-homoserinelactone(C4-HSL) and N-hexanoyl-Lhomoserine lactone (C6-HSL) significantly accelerated the spoilage process of refrigerated turbot, while the addition of 4, 5-Dihydroxypentane-2, 3-dione (DPD) prolonged the lag phase duration. Therefore, QS may be involved in the spoilage process of refrigerated turbot.

10.
J Gen Appl Microbiol ; 62(2): 60-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27118073

RESUMO

Quorum sensing (QS) is a cell-to-cell communication mechanism through which microbial cells communicate and regulate their wide variety of biological activities. N-acyl homoserine lactones (AHLs) are considered to be the most important QS signaling molecules produced by several Gram-negative bacteria. The present study aimed to screen the AHLs-producing bacteria from spoiled vacuum-packaged refrigerated turbot (Scophthalmus maximus) by biosensor assays, and the profiles of AHLs produced by these bacteria were determined using reversed-phase thin-layer chromatography (RP-TLC) and gas chromatography-mass spectrometry (GC-MS). Effects of exogenous AHLs and QS inhibitor (QSI) on the phenotypes (i.e., extracellular proteolytic activity and biofilm formation) of the AHLs-producing bacteria were also evaluated. Our results demonstrated that eight out of twenty-two isolates were found to produce AHLs. Three of the AHLs-producing isolates were identified as Serratia sp., and the other five were found to belong to the family of Aeromonas. Two isolates (i.e., S. liquefaciens A2 and A. sobria B1) with higher AHLs-producing activities were selected for further studies. Mainly, RP-TLC and GC-MS analysis revealed three AHLs, i.e., 3-oxo-C6-HSL, C8-HSL and C10-HSL were produced by S. liquefaciens A2, while five AHLs, i.e., C4-HSL, C6-HSL, C8-HSL, C10-HSL, and C12-HSL, were produced by A. sobria B1. Moreover, production of AHLs in both bacterial strains were found to be density-dependent, and the AHLs activity reached a maximum level in their middle logarithmic phase and decreased in the stationary phase. The addition of exogenous AHLs and QSI decreased the specific protease activity both of the Serratia A2 and Aeromonas B1. Exogenous AHLs inhibited the biofilm formation of Serratia A2 while it enhanced the biofilm formation in Aeromonas B1. QSI inhibited the specific protease activity and biofilm formation in both bacterial strains.


Assuntos
4-Butirolactona/análogos & derivados , Aeromonas/metabolismo , Linguados/microbiologia , Embalagem de Alimentos , Refrigeração , Serratia/metabolismo , 4-Butirolactona/biossíntese , 4-Butirolactona/farmacologia , Aeromonas/crescimento & desenvolvimento , Aeromonas/isolamento & purificação , Animais , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Técnicas Biossensoriais/métodos , Microbiologia de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Fenótipo , Proteólise/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Alimentos Marinhos/microbiologia , Serratia/crescimento & desenvolvimento , Serratia/isolamento & purificação , Vácuo
11.
Int J Food Microbiol ; 192: 26-33, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25305441

RESUMO

Quorum-sensing signals in refrigerated shrimp (Litopenaeus vannamei) undergoing spoilage were examined using bioreporter assays, thin-layer chromatography and gas chromatography-mass spectrometry, and the results revealed the presence of three types of autoinducers including acetylated homoserine lactones (AHLs) (i.e., N-hexanoyl-homoserine lactone, N-oxohexanoyl-homoserine lactone and N-octanoyl-homoserine lactone), autoinducer-2, and cyclic dipeptides (i.e., cyclo-(L-Pro-L-Leu), cyclo-(L-Leu-L-Leu) and cyclo-(L-Pro-L-Phe)). Autoinducer-2, rather than any AHL, was detected in extracts from pure cultures of the specific spoilage organisms (SSO), i.e., Shewanella putrefaciens (SS01) and Shewanella baltica (SA02). As for the cyclic peptides, only SA02 was determined to produce cyclo-(L-Pro-L-Leu). According to the transcription levels of LuxR (the master quorum-sensing regulator) in the SSO in response to exogenous autoinducers, the SSO could sense AHLs and cyclo-(L-Leu-L-Leu), rather than autoinducer-2, cyclo-(L-Leu-L-Leu) and cyclo-(L-Pro-L-Phe). In accordance with the results of LuxR expression, the production of biofilm matrixes and extracellular proteases in the SSO was regulated by exogenous AHLs and cyclo-(L-Pro-L-Leu), rather than 4,5-dihydroxy-2,3-pentanedione (the autoinducer-2 precursor), cyclo-(L-Leu-L-Leu) and cyclo-(L-Pro-L-Phe). Exogenous N-hexanoyl-homoserine lactone and cyclo-(L-Pro-L-Leu) increased the growth rates and population percentages of the SSO in shrimp samples under refrigerated storage, and interestingly, exogenous 4,5-dihydroxy-2,3-pentanedione also increased the population percentages of the SSO in vivo by inhibiting the growth of the competing bacteria. However, according to the levels of TVB-N and the volatile organic components in the shrimp samples, exogenous 4,5-dihydroxy-2,3-pentanedione did not accelerate the shrimp spoilage process as N-hexanoyl-homoserine lactone and cyclo-(L-Pro-L-Leu) did. In summary, our results suggest that quorum sensing involves the spoilage of refrigerated Litopenaeus vannamei.


Assuntos
Temperatura Baixa , Microbiologia de Alimentos , Lactonas/metabolismo , Penaeidae/microbiologia , Percepção de Quorum , Shewanella/crescimento & desenvolvimento , Shewanella/metabolismo , Animais , Cromatografia em Camada Delgada , Cromatografia Gasosa-Espectrometria de Massas , Lactonas/análise
12.
J Agric Food Chem ; 62(34): 8632-9, 2014 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-25074419

RESUMO

The mechanisms by which meat enhances human absorption of non-heme iron remain unknown. Recently, anchovy (Engraulis japonicus) muscle protein hydrolysate (AMPH) was found to mediate the formation of nanosized ferric hydrolysis products in vitro. The current paper evaluates the effects of AMPH on the bioavailability and the intestinal speciation of non-heme iron in rats, followed by an investigation of cellular uptake pathways of in vitro-formed AMPH-stabilized nanosized ferric hydrolysis products (ANPs) by polarized human intestinal epithelial (Caco-2) cells. The hemoglobin regeneration efficiencies in anemic rats followed the order ferric citrate (9.79 ± 2.02%) < commercial bare α-Fe2O3 nanoparticles (16.37 ± 6.65%) < mixture of ferric citrate and AMPH (40.33 ± 6.36%) ≈ ferrous sulfate (40.88 ± 7.67%) < ANPs (56.25 ± 11.35%). Percentage contents of intestinal low-molecular-weight iron in the groups of FC+AMPH, FeSO4, and ANPs were significantly lower than the corresponding hemoglobin regeneration efficiencies (P < 0.05), providing strong evidence for the involvement of nanosized iron in intestinal iron absorption from FC+AMPH, FeSO4, and ANPs. Calcein-fluorescence measurements of the labile iron pool of polarized Caco-2 cells revealed the involvement of both divalent transporter 1 and endocytosis in apical uptake of ANPs, with endocytosis dominating at acidic extracellular pH. Overall, AMPH enhancement of non-heme iron absorption involves a nanoparticle-mediated mechanism.


Assuntos
Anemia/metabolismo , Proteínas de Peixes/metabolismo , Absorção Intestinal , Mucosa Intestinal/metabolismo , Ferro/metabolismo , Alimentos Marinhos/análise , Anemia/dietoterapia , Anemia/fisiopatologia , Animais , Disponibilidade Biológica , Células CACO-2 , Feminino , Proteínas de Peixes/química , Peixes , Humanos , Hidrólise , Intestinos/fisiopatologia , Ferro/química , Masculino , Nanopartículas/química , Nanopartículas/metabolismo , Ratos
13.
J Exp Bot ; 62(13): 4617-25, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21642236

RESUMO

Changes in actual efficiency of PS II photochemistry, non-photochemical quenching (NPQ), content of xanthophylls and kinetics of de-epoxidation were studied in ABA-fed and non-ABA-fed leaves of rice and cabbage under NaCl stress. Salt stress induced more progressive decrease in actual efficiency of PS II photochemistry (ФPS II), higher reduction state of PS II, and a small significant increase in NPQ in NaCl-sensitive rice plants as compared with NaCl-tolerant cabbage plants, whereas exogenously supplied ABA alleviated the decrease in actual efficiency of PS II photochemistry (ФPS II), induced a lower reduction state of PS II, and caused higher capacity of NPQ in ABA-fed plants than in non-ABA-fed plants. As a result, there were higher activities of photosynthetic electron transport, higher capacity of energy dissipation, and lower cumulation of excess light in cabbage than in rice plants, and in ABA-fed leaves than in non-ABA-fed leaves. The effect of ABA was more efficient in cabbage than in rice plants. Addition of exogenous ABA resulted in enhancement of the size of the xanthophyll cycle pool, promotion of de-epoxidation of the xanthophyll cycle components, and a rise in the level of NPQ by altering the kinetics of de-epoxidation of the xanthophyll cycle. Protection from photodamage appears to be achieved by coordinated contributions by exogenous ABA and xanthophyll cycle-mediated NPQ. This variety of photoprotective mechanisms may be essential for conferring photodamage tolerance under NaCl stress.


Assuntos
Ácido Abscísico/farmacologia , Brassica/efeitos da radiação , Luz , Oryza/efeitos da radiação , Substâncias Protetoras/farmacologia , Cloreto de Sódio/toxicidade , Xantofilas/metabolismo , Ácido Abscísico/metabolismo , Brassica/efeitos dos fármacos , Brassica/metabolismo , Meia-Vida , Cinética , Oryza/efeitos dos fármacos , Oryza/metabolismo , Processos Fotoquímicos/efeitos dos fármacos , Processos Fotoquímicos/efeitos da radiação , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação
14.
J Integr Plant Biol ; 51(11): 1040-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19903225

RESUMO

Substrate selectivity of glycerol-3-phosphate acyltransferase (EC 2. 3. 1. 15) of rice (Oryza sativa L.) was explored in a comparative study of acyltransferases from seven plant species. In vitro labeling of acyl carrier protein (ACP) with (14)C or (3)H showed that acyltransferase from chill-sensitive plants, such as rice that uses either oleic (18:1) or palmitic acid (16:0) as acyl donor at comparable rates, displays lower selectivity than the enzyme from chill-resistant plants, such as spinach, which preferentially uses oleic acid (18:1) rather than palmitic acid (16:0) as an acyl donor. This may be a result of the size and character of the substrate-binding pocket of acyltransferase. Homology modeling and protein structure-based sequence alignment of acyltransferases revealed that proteins from either chill-sensitive or chill-tolerant plants shared a highly conserved domain containing the proposed substrate-binding pocket. However, the aligned residues surrounding the substrate-binding pocket are highly heterogeneous and may have an influence mainly on the size of the substrate binding pockets of acyltransferases. The substrate selectivity of acyltransferase of rice can be improved by enlarging the substrate-binding pocket using molecular biological methods.


Assuntos
Glicerol-3-Fosfato O-Aciltransferase/metabolismo , Oryza/enzimologia , Sequência de Aminoácidos , Sítios de Ligação , Biocatálise , Sequência Conservada , Evolução Molecular , Glicerol-3-Fosfato O-Aciltransferase/química , Lisofosfolipídeos/metabolismo , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Padrões de Referência , Alinhamento de Sequência , Especificidade por Substrato
15.
J Integr Plant Biol ; 50(2): 194-202, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18713442

RESUMO

In an attempt to explore the relationships between phosphatidylglycerol (PG) molecular species of thylakoid membrane lipids and sensitivities to chilling-induced photoinhibition, PG molecular species, D1 protein, electron transport activities of thylakoid membrane and the potential quantum yield (F(v)/F(m)) in rice treated under middle and low photon flux density (PFD) at 11 degrees C were analyzed by high performance liquid chromatography, enzyme hydrolysis, gas phase chromatography (GC) and so on. Results showed that the major molecular species of PGs in rice thylakoid membrane were 18:3/16:0, 18:3/16:1(3t), 18:2/16:0, 18:2/16:1(3t), 18:1/16:0, 18:1/16:1(3t), 16:0/16:0, 16:0/16:1(3t). There were large differences in the contents of unsaturated PG molecular species such as 18:1 approximately 3/16:0 approximately 16:1(3t) and saturated PG molecular species like 16:0/16:0 approximately 16:1(3t) among japonica cv 9516 (j-9516), japonica-indica hybrid F1 j-9516/i-SY63 (ji-95SY) and indica cv Shanyou 63 (i-SY63). J-9516 containing higher contents of unsaturated PG molecular species was manifest in stable D1 protein contents under chill and tolerant to chill-induced photoinhibition. In contrast to j-9516, i-SY63 with lower contents of unsaturated PG molecular species, exhibited unstable D1 protein contents under chill and was sensitive to chill-induced photoinhibition. ji-95SY containing middle contents of unsaturated PG molecular species between those of j-9516 and i-SY63, exhibited mid extent of sensitivity to chill-induced photoinhibition. The losses in D1 protein also account for the inhibition in electron transport activity of thylakoid membrane and the observed decline in F(v)/F(m). The PG molecular species that is efficient in raising chilling-resistant capacity were those containing unsaturated fatty acids, namely, unsaturated PG molecular species. These results implied that the substrate selectivity of the glycerol-3-phosphate acyltransferase in chloroplasts towards 16:0 or 18:1 displayed greatly the difference between japonica and indica rice. It was possible to enhance the capacity of resistance to chilling-induced photoinhibition by improving or modifying the GPAT gene.


Assuntos
Temperatura Baixa , Luz , Lipídeos de Membrana/metabolismo , Oryza/metabolismo , Oryza/efeitos da radiação , Fosfatidilgliceróis/metabolismo , Tilacoides/metabolismo , Transporte de Elétrons/efeitos da radiação , Ácidos Graxos Insaturados/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo
16.
Lin Chuang Er Bi Yan Hou Ke Za Zhi ; 20(1): 1-3, 2006 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-16548144

RESUMO

OBJECTIVE: To investigate the hearing at extended high frequencies of patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). METHOD: The youth group, adult group and OSAHS group were tested with pure tone audiometry and high frequency audiometry, and the response ratio was calculated. The results were statistically analysed with chi2-test and ANOVE. RESULT: In youth group, thresholds of pure tone audiometry in 4, 6, 8 kHz were increased slightly (P < 0.05). The hearing lose gradually with aging in adult group (P < 0.05). The high frequencies thresholds increased with the frequency increasing in youth group (P < 0.05). For each frequencies, the thresholds increased with aging (P < 0.05). At common frequencies hearing loss appeared in OSAHS group (P < 0.05), and more with aging (P < 0.01). The high frequency thresholds increased obviously when OSAHS group comparing with the adult group (P < 0.01), and the indicating ratio decreased obviously (P < 0.05). CONCLUSION: The common and high frequency thresholds in OSAHS group of the same age were worse than that of the adult group and it could provide the reference for the clinic.


Assuntos
Limiar Auditivo , Apneia Obstrutiva do Sono/fisiopatologia , Adolescente , Adulto , Fatores Etários , Idoso , Audiometria de Tons Puros , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Adulto Jovem
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