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1.
Ecotoxicology ; 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432458

RESUMO

Long-term frequent tillage would cause black soil degradation and serious soil erosion as soil microbial communities and soil structure are extremely sensitive to tillage process. However, there is no unified conclusion on the relationship between the distribution of soil water-stable aggregates (WSAs), and microbial community construction and diversity under long-term tillage in black soil during different seasons. In this study, we used wet-sieving method to evaluate the composition and stability of soil WSAs and employed Illumina MiSeq high-throughput sequencing technology to study the diversity, taxonomic composition and co-occurrence network properties of microbial community, comparing outcomes between uncultivated soil and long-term cultivated soil for 60 years in Keshan farm of Heilongjiang Province. The results showed that after long-term tillage, the proportion of larger than 1 mm WSAs reduced by 34.17-51.37%, and the stability of WSAs, soil pH, organic matter (OM), total nitrogen (TN) contents decreased significantly in all seasons (P < 0.05), while soil available phosphorus (AP) and available potassium (AK) contents increased remarkably (P < 0.05). The diversity of bacteria increased, while that of fungi decreased. Soil fungal communities were more susceptible to long-term tillage than bacterial and archaeal communities. Actinobacteria mainly exist in large WSAs (˃1 mm), and when their relative abundance is high, it is beneficial to improve the water-stability of black soil; while Proteobacteria and Gemmatimonadetes may exist in small WSAs (˂1 mm), whose high relative abundance will weaken the water-stability of black soil. The experimental results provide a scientific theoretical basis for sustainable utilization of black soil.

3.
Front Physiol ; 11: 593841, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33192610

RESUMO

As part of the ZOOMICS project, we set out to investigate common and diverging metabolic traits in the blood metabolome across various species by taking advantage of recent developments in high-throughput metabolomics. Here we provide the first comparative metabolomics analysis of fresh and stored human (n = 21, 10 males, 11 females), olive baboon (n = 20), and rhesus macaque (n = 20) red blood cells at baseline and upon 42 days of storage under blood bank conditions. The results indicated similarities and differences across species, which ultimately resulted in a differential propensity to undergo morphological alterations and lyse as a function of the duration of refrigerated storage. Focusing on purine oxidation, carboxylic acid, fatty acid, and arginine metabolism further highlighted species-specific metabolic wiring. For example, through a combination of steady state measurements and 13C6 15N4-arginine tracing experiments, we report an increase in arginine catabolism into ornithine in humans, suggestive of species-specific arginase 1 activity and nitric oxide synthesis-an observation that may impact the translatability of cardiovascular disease studies carried out in non-human primates (NHPs). Finally, we correlated metabolic measurements to storage-induced morphological alterations via scanning electron microscopy and hemolysis, which were significantly lower in human red cells compared to both NHPs.

4.
Mol Med Rep ; 22(6): 4499-4508, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33173959

RESUMO

Lung cancer is the most common fatal type of cancer, demonstrating high incidence rates in both sexes. Therefore, it is of vital importance to devise more effective and targeted therapies to improve the treatment quality for patients. The present study aimed to determine the effects of microRNA (miR)­379­5p on cell proliferation and apoptosis, in addition to its underlying molecular mechanisms in lung cancer. Tumor and adjacent normal tissues were obtained from patients with NSCLC and transfection experiments in A549 cells were performed using miR­379­5p mimics and pcDNA3.1­ ß­arrestin­1 (ARRB1) overexpression plasmids. The cell proliferation rate was determined using a Cell Counting Kit­8 assay and the cell apoptotic rate was analyzed using flow cytometry. Additionally, the mRNA and protein expression levels of proliferation­related signaling (PI3K, p­PI3K, AKT and p­AKT) and apoptotic­related factors (Bcl­2, Bax and caspase­3) were detected using reverse transcription­quantitative PCR and western blotting, respectively. The results of the present study revealed that miR­379­5p expression levels were downregulated, whereas ARRB1 expression levels were significantly upregulated in NSCLC tissues and cell lines. Following the successful transfection of the miR­379­5p mimic and ARRB1 overexpression plasmid, it was revealed that the overexpression of miR­379­5p inhibited cell proliferation and promoted cell apoptosis, whereas ARRB1 overexpression reversed this inhibition over proliferation and promotion of apoptosis. The increased cell apoptotic rate observed in the miR­379­5p mimics group was associated with a significant downregulation and upregulation of Bcl­2, and Bax and caspase­3 expression levels, respectively. Finally, ARRB1 was identified as a target gene of miR­379­5p. In conclusion, the expression levels of miR­379­5p were demonstrated to be significantly downregulated in lung cancer. In addition, miR­379­5p overexpression led to the decreased expression levels of Bcl­2, phosphorylated (p)­PI3K/PI3K and p­AKT/AKT, and the increased expression levels of Bax and caspase­3. Overall, this resulted in the inhibition of cell proliferation and promoted cell apoptosis by directly targeting ARRB1. Therefore, miR­379­5p may be a potential target for NSCLC treatment due to its ability to inhibit cell proliferation and accelerate the apoptotic process.

5.
Toxicol Sci ; 177(1): 235-247, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579216

RESUMO

In 2017, Opana ER was voluntarily removed from the U.S. market based on concerns that its risks outweighed its therapeutic benefits. The data that supported this conclusion were based on postmarketing evaluation that demonstrated increased intravenous abuse associated outbreaks of HIV, hepatitis C, and uniquely, a thrombotic thrombocytopenic purpura (TTP)-like syndrome. In 2017, the cause was mechanistically linked to intravenous exposure of the high-molecular weight polyethylene oxide (PEO), an excipient component of the drug product. However, it was unknown how differing PEO preparations might alter this response in vivo. Knowing the likelihood of a PEO driven atypical thrombotic microangiopathy with hemolytic uremic syndrome (TMA-HUS), this study was specifically designed with the primary objective focused on understanding the impact of PEO molecular weight on TMA-HUS in a guinea pig model of acute repeat PEO (1, 4, and 7 MDa) dosing. Results from this analysis suggest that repeated dosing with PEO 4 and 7 MDa, but not 1 MDa induced a marked intravascular hemolysis with schistocytes, mild anemia, thrombocytopenia, hemoglobinuria, and kidney injury, consistent with observations of a TMA-HUS-like syndrome. Nonetheless, observations of tissue microthrombi, complement or altered von Willebrand factor involvement were not observed, which would be consistent with a definitive TMA. Further, only 7 MDa PEO dosing was associated with marked renal hypoxia. Taken together, this study defines renal injury risk with PEO formulations >1 MDa that is driven by a robust intravascular hemolysis and potentially, tissue hypoxia.

6.
Int J Syst Evol Microbiol ; 70(5): 3037-3048, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32223835

RESUMO

Two independent strains of a Leptotrichia species (ES3154-GLUT and ES2714_GLU) were isolated from the oral cavity of northern elephant seals (Mirounga angustirostris) that were admitted to The Marine Mammal Centre facilities in California, USA. The strains were isolated from oral swabs by cultivation in PPLO broth supplemented with serum, penicillin and colistin in anaerobic conditions. The strains were Gram-negative, pleomorphic, indole-, oxidase- and catalase-negative, non-spore-forming, non-motile rods/coccobacilli in short chains. The 16S rRNA gene sequence of these strains shared 94.42 % nucleotide similarity with Oceanivirga salmonicida AVG 2115T but demonstrated ≤86.00-92.50 % nucleotide similarity to the 16S rRNA genes of other species of the family Leptotrichiaceae. The genome was sequenced for strain ES3154-GLUT. Average nucleotide identity values between strain ES3154-GLUT and 15 type strain genomes from the family Leptotrichiaceae ranged from 66.74 % vs. Sebaldella termitidis to 73.35 % vs. O. salmonicida. The whole genome phylogeny revealed that the novel species was most closely related to O. salmonicida AVG 2115T. This relationship was also confirmed by nucleotide similarity and multilocus phylogenetic analyses employing various housekeeping genes (partial 23S rRNA, rpoB, rpoC, rpoD, polC, adh, gyrA and gyrB genes). Chemotaxonomic and phenotypical features of strain ES3154-GLUT were in congruence with closely related members of the family Leptotrichiaceae, represented by similar enzyme profiles and fatty acid patterns. MALDI-TOF MS analysis was capable to clearly discriminate strain ES3154-GLUT from all currently described taxa of the family Leptotrichiaceae. Based on these data, we propose a novel species of the genus Oceanivirga, for which the name Oceanivirga miroungae sp. nov. is proposed with the type strain ES3154-GLUT (=DSM 109740T=CCUG 73653T=ATCC TSD-189T=NCTC 14411T) and one representative strain ES2714_GLU. The G+C content is 26.82 %, genome size is 1 356 983 bp.


Assuntos
Fusobactérias/classificação , Boca/microbiologia , Filogenia , Focas Verdadeiras/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , California , DNA Bacteriano/genética , Ácidos Graxos/química , Fusobactérias/isolamento & purificação , Genes Bacterianos , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , RNA Ribossômico 23S , Análise de Sequência de DNA
7.
J Infect Dis ; 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32179892

RESUMO

Human noroviruses are the most common viral agents of acute gastroenteritis. Recently, human intestinal enteroids were shown to be permissive for norovirus infection. We tested their suitability as a system to study norovirus neutralization. Hyperimmune sera raised against virus-like particles (VLPs) representing different genotypes showed highly-specific neutralization activity against GII.4 and GII.6 noroviruses. Carbohydrate blocking assays and neutralization exhibited similar patterns in antibody responses. Notably, sera produced against chimeric VLPs that presented swapped structural domains, shell and protruding (P), from different genotypes showed that neutralization is primarily mediated by antibodies mapping to the P domain of the norovirus capsid protein. This study provides empirical information on the antigenic differences among genotypes as measured by neutralization, which could guide vaccine design.

8.
Vaccine ; 38(10): 2396-2405, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32037226

RESUMO

Detergent-extracted detoxified outer membrane vesicle (dOMV) vaccines are effective at preventing invasive serogroup B meningococcal (MenB) disease caused by the homologous Neisseria meningitidis strain from which they are produced, but offer limited protection from heterologous strains. Differences in vaccine efficacy are partially due to strain-specific variations in the antigenic sequence types and expression levels of outer membrane proteins (OMPs), including the immunodominant OMP PorA. In this study, dOMV vaccines deficient in major OMPs, including PorA, PorB, and RmpM were isolated and used to immunize rabbits and mice. Serum samples were obtained from each animal and tested for antibody responses against five MenB strains. Immunization with wild type dOMVs elicited antibodies to major antigens including PorA, PorB, RmpM, and lipooligosaccharide (LOS), and demonstrated limited bactericidal activity against heterologous strains. In contrast, OMP-deficient dOMV vaccines elicited broadly cross-reactive bactericidal antibodies, with PorA/PorB-dual deficient dOMVs inducing antibodies exhibiting the greatest cross-reactivity. Enhanced killing of heterologous strains correlated with binding to unique protein bands in immunoblots, suggestive of improved immunogenicity of antigens under-represented in the wild type vaccine.

9.
Int J Syst Evol Microbiol ; 70(4): 2369-2381, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32068526

RESUMO

In 1983, Mycoplasma sp. strain 1220 was isolated in Hungary from the phallus lymph of a gander with phallus inflammation. Between 1983 and 2017, Mycoplasma sp. 1220 was also identified and isolated from the respiratory tract, liver, ovary, testis, peritoneum and cloaca of diseased geese in several countries. Seventeen studied strains produced acid from glucose and fructose but did not hydrolyse arginine or urea, and all grew under aerobic, microaerophilic and anaerobic conditions at 35 to 37 ˚C in either SP4 or pleuropneumonia-like organism medium supplemented with glucose and serum. Colonies on agar showed a typical fried-egg appearance and transmission electron microscopy revealed a typical mycoplasma cellular morphology. Molecular characterization included analysis of the following genetic loci: 16S rRNA, 23S rRNA, 16S-23S rRNA ITS, rpoB, rpoC, rpoD, uvrA, parC, topA, dnaE, fusA and pyk. The genome was sequenced for type strain 1220T. The 16S rRNA gene sequences of studied strains of Mycoplasma sp. 1220 shared 99.02-99.19 % nucleotide similarity with M. anatis strains but demonstrated ≤95.00-96.70 % nucleotide similarity to the 16S rRNA genes of other species of the genus Mycoplasma. Phylogenetic, average nucleotide and amino acid identity analyses revealed that the novel species was most closely related to Mycoplasma anatis. Based on the genetic data, we propose a novel species of the genus Mycoplasma, for which the name Mycoplasma anserisalpingitidis sp. nov. is proposed with the type strain 1220T (=ATCC BAA-2147T=NCTC 13513T=DSM 23982T). The G+C content is 26.70 mol%, genome size is 959110 bp.


Assuntos
Gansos/microbiologia , Mycoplasma/classificação , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Feminino , Genes Bacterianos , Hungria , Mycoplasma/isolamento & purificação , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Análise de Sequência de DNA
10.
Transfusion ; 60(3): 513-523, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32064619

RESUMO

BACKGROUND: Red blood cell (RBC) transfusions result in the sequestration and metabolism of storage-damaged RBCs within the spleen and liver. These events are followed by increased plasma iron concentrations that can contribute to oxidant stress and cellular injury. We hypothesized that administration of a ferroportin inhibitor (FPN-INH) immediately after acute RBC exchange transfusion could attenuate posttransfusion circulatory compartment iron exposure, by retaining iron in spleen and hepatic macrophages. STUDY DESIGN AND METHODS: Donor guinea pig blood was leukoreduced, and RBCs were preserved at 4°C. Recipient guinea pigs (n = 5/group) were exchange transfused with donor RBCs after refrigerator preservation and dosed intravenously with a small-molecule FPN-INH. Groups included transfusion with vehicle (saline), 5 mg/kg or 25 mg/kg FPN-INH. A time course of RBC morphology, plasma non-transferrin-bound iron (NTBI) and plasma hemoglobin (Hb) were evaluated. End-study spleen, liver, and kidney organ iron levels, as well as renal tissue oxidation and injury, were measured acutely (24-hr after transfusion). RESULTS: RBC transfusion increased plasma NTBI, with maximal concentrations occurring 8 hours after transfusion. Posttransfusion iron accumulation resulted in tubule oxidation and acute kidney injury. FPN inhibition increased spleen and liver parenchymal/macrophage iron accumulation, but attenuated plasma NTBI, and subsequent renal tissue oxidation/injury. CONCLUSION: In situations of acute RBC transfusion, minimizing circulatory NTBI exposure by FPN inhibition may attenuate organ-specific adverse consequences of iron exposure.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Ferro/sangue , Animais , Preservação de Sangue , Proteínas de Transporte de Cátions/antagonistas & inibidores , Transfusão de Eritrócitos/métodos , Cobaias , Humanos , Masculino , Estresse Oxidativo/fisiologia
11.
Int J Syst Evol Microbiol ; 70(1): 153-164, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31617839

RESUMO

Novel ureaplasma strains have been isolated from the genital tract of both sexes of northern elephant seals (Mirounga angustirostris; six strains) and California sea lions (Zalophus californianus; five strains) stranded along the Central California coast, USA. These strains were phenotypically and genetically characterized and compared to other seven known Ureaplasma species. All novel ureaplasma strains hydrolysed urea, but did not metabolize arginine, and all were isolated and propagated using PPLO medium supplemented with urea under aerobic, microaerophilic, and anaerobic atmospheric conditions at +35-37 °C. Transmission electron microscopy revealed typical mollicute cellular morphology. Molecular characterization included assessment of the following genetic loci: 16S rRNA, the 16S-23S ITS, 23S rRNA, rpoB, ftsH, tufB, rpoC, fusA and ureC. Complete 16S rRNA gene sequence analysis of these novel Ureaplasma species indicated that they were most closely related to each other with nucleotide identity 99.87 % and ≤93.08 % related to other known Ureaplasma species. The results of nucleotide analysis of the sequenced housekeeping genes revealed 71.68-93.02 % similarity to corresponding genes of other known Ureaplasma species. The multi-locus genetic characterization and the phylogenetic analysis of the 16S rRNA and rpoB genes of these Ureaplasma species clearly demonstrated their novelty and, reflecting their host specificites, the name Ureaplasma miroungigenitalium sp. nov. is proposed for the Ureaplasma species isolated from northern elephant seals, the type strain is ES2783-GENT (=DSM 24842T=ATCC BAA-2460T), and the name Ureaplasma zalophigenitalium sp. nov. is proposed for the Ureaplasma species isolated from California sea lions, the type strain is CSL7644-GENT (=DSM 24843T=ATCC BAA-2262T).


Assuntos
Genitália/microbiologia , Filogenia , Leões-Marinhos/microbiologia , Focas Verdadeiras/microbiologia , Ureaplasma/classificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Sequência de Bases , California , DNA Bacteriano/genética , Ácidos Graxos/química , Feminino , Genes Bacterianos , Masculino , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Análise de Sequência de DNA , Ureaplasma/isolamento & purificação
12.
Arch Microbiol ; 202(2): 411-420, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31828363

RESUMO

We describe two novel species of Acholeplasma sp. strain N93 and Mycoplasma sp. strain LR5794 which were isolated from the nasopharynx of a horse from the United Kingdom and from the oral cavity of a North American raccoon from Canada, respectively. These strains were phenotypically and genetically characterized and compared to other established Mycoplasma and Acholeplasma species. Both strains are facultative anaerobes, resistant to penicillin, and produce acid from glucose but do not hydrolyze arginine and urea. Both strains grew well in microaerophilic and anaerobic atmospheric conditions at 35-37 °C using PPLO (pleuropneumonia-like organisms) medium. Acholeplasma sp. N93 does not require serum for growth. Colonies of both strains showed a typical fried-egg appearance and transmission electron microscopy of bacterial cells revealed a typical mycoplasma cellular morphology. Molecular characterization included assessment of several genetic loci. The genetic analysis indicated that Acholeplasma sp. N93 and Mycoplasma sp. LR5794 were most closely related to A. hippikon and A. equifetale, and M. molare and M. lagogenitalium, respectively. However, both novel strains were genetically unique in comparison to other well-known Mycoplasma and Acholeplasma species. Based on the isolation source history, phenotypic, genotypic, and phylogenetic characteristics of these novel strains, we propose the name Acholeplasma equirhinis sp. nov. for Acholeplasma sp. isolated from the nasopharynx of a horse [the type strain is N93T (= DSM 106692T = ATCC TSD-139T = NCTC 14351T)], and the name Mycoplasma procyoni sp. nov. for the Mycoplasma sp. isolated from the oral cavity of a North American raccoon [the type strain is LR5794T (= DSM 106703T = ATCC TSD-141T = NCTC 14309T)].


Assuntos
Acholeplasma/isolamento & purificação , Cavalos/microbiologia , Boca/microbiologia , Mycoplasma/isolamento & purificação , Nasofaringe/microbiologia , Guaxinins/microbiologia , Acholeplasma/classificação , Acholeplasma/genética , Animais , Canadá , DNA Bacteriano/genética , Mycoplasma/classificação , Mycoplasma/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Reino Unido
13.
mBio ; 10(5)2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551337

RESUMO

GII.4 noroviruses are a major cause of acute gastroenteritis. Their dominance has been partially explained by the continuous emergence of antigenically distinct variants. To gain insights into the mechanisms of viral emergence and population dynamics of GII.4 noroviruses, we performed large-scale genomics, structural, and mutational analyses of the viral capsid protein (VP1). GII.4 noroviruses exhibited a periodic replacement of predominant variants with accumulation of amino acid substitutions. Genomic analyses revealed (i) a large proportion (87%) of conserved residues; (ii) variable residues that map on the previously determined antigenic sites; and (iii) variable residues that map outside the antigenic sites. Residues in the third pattern category formed motifs on the surface of VP1, which suggested extensions of previously predicted and new uncharacterized antigenic sites. The role of two motifs (C and G) in the antigenic makeup of the GII.4 capsid protein was confirmed with monoclonal antibodies and carbohydrate blocking assays. Amino acid profiles from antigenic sites (A, C, D, E, and G) correlated with the circulation patterns of GII.4 variants, with three of them (A, C, and G) containing residues (352, 357, 368, and 378) linked with the diversifying selective pressure on the emergence of new GII.4 variants. Notably, the emergence of each variant was followed by stochastic diversification with minimal changes that did not progress toward the next variant. This report provides a methodological framework for antigenic characterization of viruses and expands our understanding of the dynamics of GII.4 noroviruses and could facilitate the design of cross-reactive vaccines.IMPORTANCE Noroviruses are an important cause of viral gastroenteritis around the world. An obstacle delaying the development of norovirus vaccines is inadequate understanding of the role of norovirus diversity in immunity. Using a population genomics approach, we identified new residues on the viral capsid protein (VP1) from GII.4 noroviruses, the predominant genotype, that appear to be involved in the emergence and antigenic topology of GII.4 variants. Careful monitoring of the substitutions in those residues involved in the diversification and emergence of new viruses could help in the early detection of future novel variants with pandemic potential. Therefore, this novel information on the antigenic diversification could facilitate GII.4 norovirus vaccine design.


Assuntos
Anticorpos Antivirais/genética , Variação Antigênica/genética , Infecções por Caliciviridae/genética , Variação Genética , Metagenômica , Norovirus/genética , Pandemias , Infecções por Caliciviridae/epidemiologia , Humanos
14.
Bioresour Technol ; 290: 121660, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31326651

RESUMO

Biological pretreatment can increase the methane production of anaerobic digestion. In this study, stover was pretreated via microbial consortium prior to anaerobic digestion; through 16S rRNA gene and 16S rRNA amplicon sequencing and metatranscriptomic analysis, and the effects of the pretreatment on the microbial community and critical factors of the increased methane production were studied. Microbial community structure was less affected by the pretreatment, which ensures the stable performance of anaerobic digestion. The methane production increased by 62.85% at the peak phase compared to the untreated stover. The activity of Methanosaeta increased from 2.0% to 10.1%, significantly enhancing the ability of the community to capture acetic acid and reduce CO2 to methane. The main contribution to the increase in methane production was a unique acetyl-CoA synthetase, which showed significant up-regulation (121.8%). This research demonstrated the importance of Methanosaeta and its unique metabolic pathways in anaerobic digestion utilizing a biological pretreatment.


Assuntos
Metano , Microbiota , Anaerobiose , Reatores Biológicos , Consórcios Microbianos , RNA Ribossômico 16S
15.
Free Radic Biol Med ; 141: 348-361, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31302228

RESUMO

Cardiovascular effects were reported to occur in humans and in animal models during transfusion with hemoglobin (Hb)-based oxygen therapeutics. The effects of Hb's iron redox states on cardiac parameters during hypoxia/reoxygenation are however poorly defined. We hypothesize that acute exposures to ferric Hb during hypoxia leads to cardiomyocyte injury and an impaired left ventricular response accompanied by cardiac mitochondrial bioenergetic dysfunction. Recovery of left ventricular functions in an isolated rat heart Langendorff perfusion system was observed following perfusion with ferrous but not with ferric Hb. Ferric Hb induced the development of heart lesions, and impairment of the respiratory chain complex activity. Under normoxia, a sharp decline in cardiac parameters was observed following co-perfusion of low (20 µM) and high (100 µM) ascorbic acid (Asc) with ferrous Hb. This trend continued with ferric Hb co-perfusion, but only at the higher concentration of Asc. These observations suggest that perfusion of the hypoxic heart with ferric Hb increases oxidative stress thereby resulting in cardiac dysfunction. Intervention with Asc to reduce ferric Hb may offer a strategy to control Hb toxicity; however, timing of administration, and dosage of Asc may require individual optimization to target specific redox forms of Hb.


Assuntos
Coração/efeitos dos fármacos , Miocárdio/metabolismo , Oxigênio/farmacologia , Oxiemoglobinas/farmacologia , Animais , Ácido Ascórbico/farmacologia , Complexo IV da Cadeia de Transporte de Elétrons/efeitos dos fármacos , Complexo IV da Cadeia de Transporte de Elétrons/genética , Coração/fisiopatologia , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Ventrículos do Coração/fisiopatologia , Hemoglobinas/metabolismo , Humanos , Hipóxia/metabolismo , Ferro/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Miocárdio/patologia , Técnicas de Cultura de Órgãos , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos
16.
J Virol ; 93(19)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31270231

RESUMO

The potential avian influenza pandemic remains a threat to public health, as the avian-origin influenza A(H7N9) virus has caused more than 1,560 laboratory-confirmed human infections since 2013, with nearly 40% mortality. Development of low-pathogenic candidate vaccine viruses (CVVs) for vaccine production is essential for pandemic preparedness. However, the suboptimal growth of CVVs in mammalian cells and chicken eggs is often a challenge. By introducing a single adaptive substitution, G218E, into the hemagglutinin (HA), we generated reassortant A(H7N9)-G218E CVVs that were characterized by significantly enhanced growth in both cells and eggs. These G218E CVVs retained the original antigenicity, as determined by a hemagglutination inhibition assay, and effectively protected ferrets from lethal challenge with the highly pathogenic parental virus. We found that the suboptimal replication of the parental H7 CVVs was associated with impeded progeny virus release as a result of strong HA receptor binding relative to weak neuraminidase (NA) cleavage of receptors. In contrast, the G218E-mediated growth improvement was attributed to relatively balanced HA and NA functions, resulted from reduced HA binding to both human- and avian-type receptors, and thus facilitated NA-mediated virus release. Our findings revealed that a single amino acid mutation at residue 218 of the HA improved the growth of A(H7N9) influenza virus by balancing HA and NA functions, shedding light on an alternative approach for optimizing certain influenza CVVs.IMPORTANCE The circulating avian influenza A(H7N9) has caused recurrent epidemic waves with high mortality in China since 2013, in which the alarming fifth wave crossing 2016 and 2017 was highlighted by a large number of human infections and the emergence of highly pathogenic avian influenza (HPAI) A(H7N9) strains in human cases. We generated low-pathogenic reassortant CVVs derived from the emerging A(H7N9) with improved virus replication and protein yield in both MDCK cells and eggs by introducing a single substitution, G218E, into HA, which was associated with reducing HA receptor binding and subsequently balancing HA-NA functions. The in vitro and in vivo experiments demonstrated comparable antigenicity of the G218E CVVs with that of their wild-type (WT) counterparts, and both the WT and the G218E CVVs fully protected ferrets from parental HPAI virus challenge. With high yield traits and the anticipated antigenicity, the G218E CVVs should benefit preparedness against the threat of an A(H7N9) influenza pandemic.


Assuntos
Substituição de Aminoácidos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Subtipo H7N9 do Vírus da Influenza A/crescimento & desenvolvimento , Vacinas contra Influenza/genética , Proteínas Mutantes/metabolismo , Vírus Reordenados/crescimento & desenvolvimento , Adaptação Biológica , Animais , Embrião de Galinha , Modelos Animais de Doenças , Cães , Furões , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Células Madin Darby de Rim Canino , Proteínas Mutantes/genética , Infecções por Orthomyxoviridae/prevenção & controle , Vírus Reordenados/genética , Análise de Sobrevida , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Ligação Viral , Replicação Viral
17.
Blood Transfus ; 17(4): 296-306, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31184583

RESUMO

BACKGROUND: The goal of red blood cell transfusion is to improve tissue oxygenation. Assessment of red blood cell quality and individualised therapeutic needs can be optimised using direct oxygen (O2) measurements to guide treatment. Electron paramagnetic resonance oximetry is capable of accurate, repeatable and minimally invasive measurements of tissue pO2. Here we present preclinical proof-of-concept of the utility of electron paramagnetic resonance oximetry in an experimental setting of acute blood loss, transfusion, and post-transfusion monitoring. MATERIALS AND METHODS: Donor rat blood was collected, leucocyte-reduced, and stored at 4 °C in AS-3 for 1, 7 and 14 days. Red blood cell morphology, O2 equilibrium, p50 and Hill numbers from O2 binding and dissociation curves were evaluated in vitro. Recipient rats were bled and maintained at a mean arterial pressure of 30-40 mmHg and hind limb muscle (biceps femoris) pO2 at 25-50% of baseline. Muscle pO2 was monitored continuously over the course of experiments to assess the effectiveness of red blood cell preparations at different stages of blood loss and restoration. RESULTS: Red blood cell morphology, O2 equilibrium and p50 values of intra-erythrocyte haemoglobin were significantly altered by refrigerated storage for both 7 and 14 days. Transfusion of red blood cells stored for 7 or 14 days demonstrated an equivalently impaired ability to restore hind limb muscle pO2, consistent with in vitro observations and transfusion with albumin. Red blood cells refrigerated for 1 day demonstrated normal morphology, in vitro oxygenation and in vivo restoration of tissue pO2. DISCUSSION: Electron paramagnetic resonance oximetry represents a useful approach to assessing the quality of red blood cells and subsequent transfusion effectiveness.


Assuntos
Espectroscopia de Ressonância de Spin Eletrônica , Transfusão de Eritrócitos , Eritrócitos/citologia , Oximetria , Animais , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Transfusão de Eritrócitos/métodos , Eritrócitos/metabolismo , Hemorragia/terapia , Masculino , Oximetria/métodos , Oxigênio/metabolismo , Ratos , Ratos Endogâmicos Lew , Resultado do Tratamento
18.
Int J Syst Evol Microbiol ; 69(2): 363-370, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30543510

RESUMO

Five Mycoplasma strains have been isolated from the oropharynx of southern sea otters (Enhydra lutris nereis) from the Central California Coast, USA. These strains were phenotypically and genetically characterized and compared to other established Mycoplasma species. All five strains hydrolysed arginine but not urea, but did not produce acid from glucose, and all were isolated and propagated under anaerobic and aerobic atmospheric conditions at +35-37 ˚C using either SP4 or PPLO medium supplemented with arginine. Colonies on solid medium showed a typical fried-egg appearance and transmission electron microscopy revealed a typical mycoplasma cellular morphology. Molecular characterization included assessment of the following genetic loci: 16S rRNA, 16S-23S rRNA ITS, rpoB, rpoC, polC, topIIA, tufB, arcA and smc. Complete 16S rRNA gene sequence analysis indicated that these strains were most closely related to M.ycoplasma phocicerebrale, and to M.ycoplasma arginini, M.ycoplasma gateae and M.ycoplasma canadense with nucleotide similarities of 99 and 98 %, respectively. Nucleotide analysis of other genetic loci revealed 73-91 % nucleotide similarity to the corresponding genes of the above closely related species. All five strains clustered into a distinct group on the 16S rRNA and rpoB phylogenetic trees. Serological testing via growth inhibition and metabolic inhibition tests employing antiserum to type strains of M. phocicerebrale, M. arginini, M. gateae and M. canadense failed to recognize these novel strains. Our results suggest that the strains isolated from southern sea otters represent a novel species of the genus Mycoplasma, for which the name Mycoplasma enhydrae sp. nov. is proposed; the type strain is 6243-11T (=DSM 106704T=ATCC TSD-140T).


Assuntos
Mycoplasma/classificação , Lontras/microbiologia , Faringe/microbiologia , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , California , DNA Bacteriano/genética , Genes Bacterianos , Mycoplasma/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
19.
J Cell Biochem ; 120(1): 481-492, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30246263

RESUMO

BACKGROUND: As a common disease, the incidence of atherosclerosis (AS) in the world is high. Therefore, we aimed to evaluate the involvement of hydrogen sulfide (H 2 S)/cystathionine γ-lyase (CSE) in the pathogenesis of AS as well as their possible signaling pathways. METHODS: Enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot analysis were used to detect the effect of CSE on the expression of inflammatory cytokines, ie, H 2 S, thioredoxin-interacting protein (TXNIP), NLRP3, apoptosis-associated speck-like protein (ASC), caspase-1, and interleukin (IL)-1ß. In addition, immunohistochemistry and Western blot analysis were performed to detect the levels of TXNIP, NLRP3, ASC, caspase-1, IL-1ß, and IL-18 among different groups. RESULT: Knockdown of CSE by the transfection of CSE small interfering RNA upregulated the levels of two inflammatory cytokines, ie, IL-1ß and IL-18. In addition, the downregulation of CSE promoted the expression of TXNIP, NLRP3, ASC, caspase-1, and IL-1ß in THP-1 cells. Meanwhile, treating the cells with sodium hydrosulfide (NaHS) inhibited the productions of IL-1ß and IL-18. Furthermore, upregulation of H 2 S synthesis by treating the cells with NaHS also reduced the protein levels of TXNIP, NLRP3, ASC, caspase-1, and IL-1ß. Finally, the protein levels of TXNIP and NLRP3 in the AS group were much higher than those in the AS + H 2 S group, which in turn was higher than the sham group. In addition, the AS group displayed the highest protein levels of TXNIP, NLRP3, ASC, caspase-1, IL-1ß, and IL-18, while the levels of these proteins in the AS + H 2 S group were higher than those in the sham group. CONCLUSION: In summary, the present finding suggested a possible linkage between H 2 S metabolism and AS through the H 2 S/CSE-TXNIP-NLRP3-IL-18/IL-1ß-nitric oxide (NO) signaling pathway.


Assuntos
Aterosclerose/metabolismo , Aterosclerose/patologia , Cistationina gama-Liase/genética , Cistationina gama-Liase/metabolismo , Sulfeto de Hidrogênio/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Proteínas de Transporte/metabolismo , Caspase 1/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Humanos , Inflamassomos/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Óxido Nítrico/metabolismo , RNA Interferente Pequeno/genética , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Transdução de Sinais/efeitos dos fármacos , Sulfetos/farmacologia , Transfecção
20.
Sheng Wu Gong Cheng Xue Bao ; 34(11): 1794-1808, 2018 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-30499275

RESUMO

In order to clarify dynamic change of microbial community composition and to identify key functional bacteria in the cellulose degradation consortium, we studied several aspects of the biodegradation of filter papers and rice straws by the microbial consortium, the change of substrate degradation, microbial biomass and pH of fermentation broth. We extracted total DNA of the microbial consortium in different degradation stages for high-throughput sequencing of amplicons of bacterial 16 S rRNA genes. Based on the decomposition characteristics test, we defined the 12th, 72nd and 168th hours after inoculation as the initial stage, peak stage and end stage of degradation, respectively. The microbial consortium was mainly composed of 1 phylum, 2 classes, 2 orders, 7 families and 11 genera. With cellulose degradation, bacteria in the consortium showed different growth trends. The relative abundance of Brevibacillus and Caloramator decreased gradually. The relative abundance of Clostridium, Bacillus, Geobacillus and Cohnella increased gradually. The relative abundance of Ureibacillus, Tissierella, Epulopiscium was the highest in peak stage. The relative abundance of Paenibacillus and Ruminococcus did not change obviously in each stage. Above-mentioned 11 main genera all belonged to Firmicutes, which are thermophilic, broad pH adaptable and cellulose or hemicellulose degradable. During cellulose degradation by the microbial consortium, aerobic bacteria were dominant functional bacteria in the initial stage. However, the relative abundance of anaerobic bacteria increased gradually in middle and end stage, and replaced aerobic bacteria to become main bacteria to degrade cellulose.


Assuntos
Bactérias/classificação , Celulose/metabolismo , Consórcios Microbianos , Bactérias/metabolismo , Biodegradação Ambiental , DNA Bacteriano/genética , RNA Ribossômico 16S/genética
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