Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Bioelectrochemistry ; 160: 108770, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38943780

RESUMO

This study assessed the viability of an anion-exchange microbial fuel cell (MFC) for extracting electricity from palm oil mill effluent (POME), a major pollutant in palm-oil producing regions due to increasing demand. The MFC incorporated a tubular membrane electrode assembly (MEA) with an air core, featuring a carbon-painted carbon-cloth cathode, an anion exchange membrane (AEM), and a nonwoven graphite fabric (NWGF) anode. An additional carbon brush (CB) anode was placed adjacent to the tubular MEA. The MFC operated under semi-batch conditions with POME replacement every 7 days. Results showed superior performance of the AEM, with the highest power density (Pmax) observed in POME-treated MFCs. Current and power density increased with CB addition; the best chemical oxygen demand (COD) removal efficiency reached 73 %, decreasing from 1249 to 332 mg/L with three CBs. The Pmax was 0.18 W/m-2(-|-) with 1000 mg/L COD and three CBs, dropping to 0.0031 W/m-2(-|-) without CB and at 410 mg/L COD. Anode resistance, calculated using organic matter supplementation, COD, and anode surface area, decreased with increased COD or surface area, improving electricity production. AEM and CB compatibility synergistically enhanced MFC performance, offering potential for POME wastewater treatment and energy recovery.

2.
Rev Bras Parasitol Vet ; 32(4): e011923, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38055438

RESUMO

In vitro excystation of cysts of microscopically identified Chilomastix mesnili and Retortamonas sp. isolated from Japanese macaques and Retortamonas sp. isolated from small Indian mongooses could be induced using an established protocol for Giardia intestinalis and subsequently by culturing with H2S-rich Robinson's medium supplemented with Desulfovibrio desulfuricans. Excystation usually began 2 h after incubation in Robinson's medium. DNA was isolated from excysted flagellates after 4 h of incubation or from cultured excysted flagellates. Phylogenetic analysis based on their 18S rRNA genes revealed that two isolates of C. mesnili from Japanese macaques belonged to the same cluster as a C. mesnili isolate from humans, whereas a mammalian Retortamonas sp. isolate from a small Indian mongoose belonged to the same cluster as that of an amphibian Retortamonas spp. isolate from a 'poison arrow frog' [sequence identity to AF439347 (94.9%)]. These results suggest that the sequence homology of the 18S rRNA gene of the two C. mesnili isolates from Japanese macaques was similar to that of humans, in addition to the morphological similarity, and Retortamonas sp. infection of the amphibian type in the small Indian mongoose highlighted the possibility of the effect of host feeding habitats.


Assuntos
Herpestidae , Parasitos , Retortamonadídeos , Humanos , Animais , Filogenia , Retortamonadídeos/genética , Herpestidae/genética , Macaca fuscata/genética , RNA Ribossômico 18S/genética
3.
Microorganisms ; 11(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36838314

RESUMO

Graphene oxide (GO), a chemically oxidized sheet of graphite, has been used as a conductive carbon carrier of microbes to boost various bioelectrochemical reactions. However, the types of microbes that can reduce GO have rarely been investigated. In this study, a strain of GO-reducing bacteria, named NIT-SL11, which was obtained from a hydrogel of microbially reduced GO and anaerobic sludge that converts sewage to electricity, was phylogenically identified as a novel strain of Geotalea uraniireducens. Considering the current lack of information on the electrogenic ability of the bacterium and its physicochemical and chemotaxonomic characteristics, the polyphasic characterization of the Geotalea uraniireducens strain NIT-SL11 was performed. NIT-SL11 utilized various organic acids, such as lactate, benzoate, and formate, as electron donors and exhibited respiration using GO, electrodes, fumarate, and malate. The strain contained C16:1ω7c and C16:0 as the major fatty acids and MK-8 and 9 as the major respiratory quinones. The complete genome of NIT-SL11 was 4.7 Mbp in size with a G+C content of 60.9%, and it encoded 80 putative c-type cytochromes and 23 type IV pili-related proteins. The possible extracellular electron transfer (EET) pathways of the strain were the porin-cytochrome (Pcc) EET pathway and type IV pili-based pathway.

4.
Cell Rep ; 42(2): 112023, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36729835

RESUMO

At the moment of union in fertilization, sperm and oocyte are transcriptionally silent. The ensuing onset of embryonic transcription (embryonic genome activation [EGA]) is critical for development, yet its timing and profile remain elusive in any vertebrate species. We here dissect transcription during EGA by high-resolution single-cell RNA sequencing of precisely synchronized mouse one-cell embryos. This reveals a program of embryonic gene expression (immediate EGA [iEGA]) initiating within 4 h of fertilization. Expression during iEGA produces canonically spliced transcripts, occurs substantially from the maternal genome, and is mostly downregulated at the two-cell stage. Transcribed genes predict regulation by transcription factors (TFs) associated with cancer, including c-Myc. Blocking c-Myc or other predicted regulatory TF activities disrupts iEGA and induces acute developmental arrest. These findings illuminate intracellular mechanisms that regulate the onset of mammalian development and hold promise for the study of cancer.


Assuntos
Embrião de Mamíferos , Perfilação da Expressão Gênica , Masculino , Animais , Camundongos , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Sêmen , Expressão Gênica , Desenvolvimento Embrionário/genética , Mamíferos/genética
5.
Microorganisms ; 9(9)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34576847

RESUMO

In this study, a novel electrogenic bacterium denoted as strain NIT-T3 of the genus Desulfuromonas was isolated from a graphene-oxide-reducing enrichment culture that was originally obtained from a mixture of seawater and coastal sand. Strain NIT-T3 utilized hydrogen and various organic acids as electron donors and exhibited respiration using electrodes, ferric iron, nitrate, and elemental sulfur. The strain contained C16:1ω7c, C16:0, and C15:0 as major fatty acids and MK-8, 9, and 7 as the major respiratory quinones. Strain NIT-T3 contained four 16S rRNA genes and showed 95.7% similarity to Desulfuromonasmichiganensis BB1T, the closest relative. The genome was 4.7 Mbp in size and encoded 76 putative c-type cytochromes, which included 6 unique c-type cytochromes (<40% identity) compared to those in the database. Based on the physiological and genetic uniqueness, and wide metabolic capability, strain NIT-T3 is proposed as a type strain of 'Desulfuromonas versatilis' sp. nov.

6.
Sci Rep ; 7: 41838, 2017 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-28176811

RESUMO

Although the existence of cancer stem cells in intestine tumors has been suggested, direct evidence has not been yet provided. Here, we showed, using the multicolor lineage-tracing method and mouse models of intestinal adenocarcinoma and adenoma that Bmi1- or Lgr5- positive tumorigenic cells clonally expanded in proliferating tumors. At tumor initiation and during tumor propagation in the colon, the descendants of Lgr5-positive cells clonally proliferated to form clusters. Clonal analysis using ubiquitous multicolor lineage tracing revealed that colon tumors derived from Lgr5-positive cells were monoclonal in origin but eventually merged with neighboring tumors, producing polyclonal tumors at the later stage. In contrast, the origin of small intestine tumors was likely polyclonal, and during cancer progression some clones were eliminated, resulting in the formation of monoclonal tumors, which could merge similar to colon tumors. These results suggest that in proliferating intestinal neoplasms, Bmi1- or Lgr5-positive cells represent a population of cancer stem cells, whereas Lgr5-positive cells also function as cells-of-origin for intestinal tumors.


Assuntos
Biomarcadores Tumorais/genética , Evolução Clonal , Neoplasias Intestinais/genética , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genética , Receptores Acoplados a Proteínas G/genética , Animais , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Células Cultivadas , Neoplasias Intestinais/metabolismo , Neoplasias Intestinais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neoplásicas/citologia , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
7.
Sci Rep ; 6: 39386, 2016 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-28004815

RESUMO

We recently reported that the polycomb complex protein Bmi1 is a marker for lingual epithelial stem cells (LESCs), which are involved in the long-term maintenance of lingual epithelial tissue in the physiological state. However, the precise role of LESCs in generating tongue tumors and Bmi1-positive cell lineage dynamics in tongue cancers are unclear. Here, using a mouse model of chemically (4-nitroquinoline-1-oxide: 4-NQO) induced tongue cancer and the multicolor lineage tracing method, we found that each unit of the tumor was generated by a single cell and that the assembly of such cells formed a polyclonal tumor. Although many Bmi1-positive cells within the tongue cancer specimens failed to proliferate, some proliferated continuously and supplied tumor cells to the surrounding area. This process eventually led to the formation of areas derived from single cells after 1-3 months, as determined using the multicolor lineage tracing method, indicating that such cells could serve as cancer stem cells. These results indicate that LESCs could serve as the origin for tongue cancer and that cancer stem cells are present in tongue tumors.


Assuntos
Linhagem da Célula/fisiologia , Epitélio/metabolismo , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Neoplasias da Língua/metabolismo , 4-Nitroquinolina-1-Óxido/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Língua/metabolismo , Neoplasias da Língua/induzido quimicamente
8.
Biochem Biophys Res Commun ; 466(3): 333-8, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26362184

RESUMO

The skin is responsible for a variety of physiological functions and is critical for wound healing and repair. Therefore, the regenerative capacity of the skin is important. However, stem cells responsible for maintaining the acral epithelium had not previously been identified. In this study, we identified the specific stem cells in the acral epithelium that participate in the long-term maintenance of sweat glands, ducts, and interadnexal epidermis and that facilitate the regeneration of these structures following injury. Lgr6-positive cells and Bmi1-positive cells were found to function as long-term multipotent stem cells that maintained the entire eccrine unit and the interadnexal epidermis. However, while Lgr6-positive cells were rapidly cycled and constantly supplied differentiated cells, Bmi1-positive cells were slow to cycle and occasionally entered the cell cycle under physiological conditions. Upon irradiation-induced injury, Bmi1-positive cells rapidly proliferated and regenerated injured epithelial tissue. Therefore, Bmi1-positive stem cells served as reservoir stem cells. Lgr5-positive cells were rapidly cycled and maintained only sweat glands; therefore, we concluded that these cells functioned as lineage-restricted progenitors. Taken together, our data demonstrated the identification of stem cells that maintained the entire acral epithelium and supported the different roles of three cellular classes.


Assuntos
Epitélio/metabolismo , Complexo Repressor Polycomb 1/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Células-Tronco/citologia , Glândulas Sudoríparas/fisiologia , Animais , Peso Corporal , Linhagem da Célula , Proliferação de Células , Epiderme/metabolismo , Feminino , Regulação da Expressão Gênica , Imageamento Tridimensional , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células-Tronco Multipotentes/citologia , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genética , Receptores Acoplados a Proteínas G/genética , Pele/metabolismo
9.
Sci Rep ; 4: 6175, 2014 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-25146451

RESUMO

Asingle cells in undifferentiated spermatogonia are considered to be the most primitive forms of germ stem cells (GSCs). Although GFRα1 is thought to be a marker of Asingle cells, we found that Bmi1(High) is more specific than GFRα1 for Asingle cells. Bmi1(High) expression in Asingle cells is correlated with seminiferous stages, and its expression was followed by the proliferative stage of Asingle GSCs. In contrast, GFRα1 expression was seminiferous stage-independent. Fate analyses of EdU-positive Bmi1(High)-positive cell-derived Asingle cells revealed that these cells self-renewed or generated transient amplifying Apaired cells. Bmi1(High)-positive cells were resistant to irradiation-induced injury, after which they regenerated. Elimination of Bmi1(High)-positive cells from seminiferous tubules resulted in the appearance of tubules with seminiferous stage mismatches. Thus, in this study, we found that Bmi1(High) is a seminiferous stage-dependent marker for long-term GSCs and that Bmi1(High)-positive cells play important roles in maintaining GSCs and in regenerating spermatogenic progenitors after injury.


Assuntos
Expressão Gênica , Células Germinativas/metabolismo , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genética , Células-Tronco/metabolismo , Animais , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Deleção de Genes , Células Germinativas/citologia , Células Germinativas/efeitos da radiação , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Imunofenotipagem , Masculino , Camundongos , Camundongos Transgênicos , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Regeneração , Túbulos Seminíferos/citologia , Espermatogônias/citologia , Espermatogônias/metabolismo , Espermatogônias/efeitos da radiação , Células-Tronco/citologia , Células-Tronco/efeitos da radiação
10.
J Biosci Bioeng ; 118(5): 529-32, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24794625

RESUMO

We enriched an anaerobic, soil-free 4-chlorophenol (4-CP)-degrading culture under iron-reducing conditions. The [ring-(14)C(U)]4-CP tracer experiment showed that 65 µM 4-CP mineralized to CO2 and CH4 through phenol, 4-hydroxybenzoate, and benzoate intermediates over 60 days. 16S rRNA gene analyses suggested the involvement of Dehalobacterium in the 4-CP dechlorination in the culture.


Assuntos
Bacillales/crescimento & desenvolvimento , Bacillales/metabolismo , Clorofenóis/metabolismo , Ferro/metabolismo , Anaerobiose , Bacillales/genética , Bacillales/isolamento & purificação , Dióxido de Carbono/metabolismo , Halogenação , Ferro/química , Metano/metabolismo , Oxirredução , Parabenos/metabolismo , Fenol/metabolismo , RNA Ribossômico 16S/genética
11.
Development ; 137(19): 3281-91, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20724447

RESUMO

The oocytes of vertebrates are typically arrested at metaphase II (mII) by the cytostatic factor Emi2 until fertilization. Regulatory mechanisms in Xenopus Emi2 (xEmi2) are understood in detail but contrastingly little is known about the corresponding mechanisms in mammals. Here, we analyze Emi2 and its regulatory neighbours at the molecular level in intact mouse oocytes. Emi2, but not xEmi2, exhibited nuclear targeting. Unlike xEmi2, separable N- and C-terminal domains of mouse Emi2 modulated metaphase establishment and maintenance, respectively, through indirect and direct mechanisms. The C-terminal activity was mapped to the potential phosphorylation target Tx(5)SxS, a destruction box (D-box), a lattice of Zn(2+)-coordinating residues and an RL domain. The minimal region of Emi2 required for its cytostatic activity was mapped to a region containing these motifs, from residue 491 to the C terminus. The cytostatic factor Mos-MAPK promoted Emi2-dependent metaphase establishment, but Mos autonomously disappeared from meiotically competent mII oocytes. The N-terminal Plx1-interacting phosphodegron of xEmi2 was apparently shifted to within a minimal fragment (residues 51-300) of mouse Emi2 that also contained a calmodulin kinase II (CaMKII) phosphorylation motif and which was efficiently degraded during mII exit. Two equimolar CaMKII gamma isoform variants were present in mII oocytes, neither of which phosphorylated Emi2 in vitro, consistent with the involvement of additional factors. No evidence was found that calcineurin is required for mouse mII exit. These data support a model in which mammalian meiotic establishment, maintenance and exit converge upon a modular Emi2 hub via evolutionarily conserved and divergent mechanisms.


Assuntos
Proteínas F-Box/metabolismo , Metáfase , Sequência de Aminoácidos , Animais , Proteínas F-Box/química , Proteínas F-Box/genética , Feminino , Masculino , Camundongos , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas c-mos/genética , Proteínas Proto-Oncogênicas c-mos/metabolismo , Alinhamento de Sequência , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/genética , Xenopus laevis/metabolismo
12.
Intervirology ; 53(4): 193-202, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20332648

RESUMO

OBJECTIVE: Mumps virus is isolated in Vero cells and, recently, B95a cells have been reported to be susceptible to it. Currently circulating wild-type mumps virus strains (genotypes B, G, J and L) induced cytopathic effects in both Vero and B95a cells. On the other hand, the Hoshino vaccine strain (KO3) did not induce cytopathic effects in B95a cells. In this study, differences in fusion inducibility were investigated. METHODS: Nucleotide sequences of the fusion (F) and hemagglutinin-neuraminidase (HN) protein regions were compared. The F and HN expression plasmids were constructed and fusion analysis was conducted, using recombinant F expression plasmids under the control of T7 RNA polymerase. RESULTS: Extensive cell fusion was observed when B95a cells were transfected with the wild-type F expression plasmid as the F expression partner; 13-16 amino acid differences were observed in the F protein region between the KO3 and the wild types. F expression plasmids with leucine at position 383 of the F protein induced large cell fusion in B95a cells. CONCLUSION: Leucine at position 383 of the F protein of the wild types was the critical amino acid for fusion inducibility in B95a cells.


Assuntos
Leucina/fisiologia , Vírus da Caxumba/fisiologia , Proteínas Virais de Fusão/fisiologia , Internalização do Vírus , Animais , Callithrix , Linhagem Celular , Chlorocebus aethiops , Expressão Gênica , Vetores Genéticos , Proteína HN/genética , Leucina/genética , Vírus da Caxumba/genética , Plasmídeos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Proteínas Virais de Fusão/genética
13.
Drug Metab Dispos ; 36(7): 1206-11, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18436619

RESUMO

The possibility of interactions between natural products/supplements and conventional prescription medicines is one of the most important issues in pharmacotherapeutic safety. Recently, we reported that some terpenoids such as (R)-(+)-citronellal and glycyrrhetic acid, which are present in herbal medicines, can act as inhibitors of P-glycoprotein (MDR1/ABCB1). In the present study, the effects of seven terpenoids on multidrug resistance-associated protein 2 (MRP2/ABCC2) and breast cancer resistance protein (BCRP/ABCG2)-mediated transport were investigated in vitro. Membrane vesicles were prepared from MRP2 cDNA transfected Sf9 cells derived from pupal ovarian tissue of Spodoptera frugiperda, a fall armyworm, and BCRP cDNA transfected LLC-PK1 cells derived from porcine kidney. MRP2- or BCRP-mediated efflux transport was measured as ATP-dependent accumulation of [(3)H]estradiol 17-beta-d-glucuronide (E(2)17betaG) into membrane vesicles collected by a rapid filtration technique. The effects of (R)-(+)-citronellal, (S)-(-)-beta-citronellol, alpha-terpinene, terpinolene, (-)-beta-pinene, abietic acid, and glycyrrhetic acid on the intravesicular accumulation of [(3)H]E(2)17betaG were examined. Large decreases in the [(3)H]E(2)17betaG accumulation into vesicles from MRP2-overexpressing Sf9 cells were observed in the presence of glycyrrhetic acid and abietic acid, and their IC(50) values were about 20 and 51 microM, respectively. [(3)H]E(2)17betaG accumulation into vesicles from BCRP-overexpressing LLC-PK1 cells was suppressed by only glycyrrhetic acid, with an IC(50) value of about 39 microM. Other terpenoids used in this study did not alter the ATP-dependent accumulation of [(3)H]E(2)17betaG. These findings suggest that glycyrrhetic acid and abietic acid can potently inhibit MRP2- or BCRP-mediated membrane transport and may interact with their substrates in pharmacokinetic processes.


Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas de Neoplasias/antagonistas & inibidores , Terpenos/farmacologia , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Células LLC-PK1 , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas de Neoplasias/genética , Spodoptera , Suínos
14.
Development ; 134(21): 3941-52, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17933795

RESUMO

Mammalian metaphase II (mII) exit and embryogenesis are induced at fertilisation by a signal thought to come from the sperm protein, phospholipase C-zeta (PLCZ1). Meiotic progression can also be triggered without sperm, as in parthenogenesis, although the classic mouse in vivo parthenogenetic model, LT/Sv, fails in meiosis I owing to an unknown molecular etiology. Here, we dissect PLCZ1 specificity and function in vivo and address its ability to interfere with maternal meiotic exit. Wild-type mouse Plcz1 expression was restricted to post-pubertal testes and the brains of both sexes, with region-specifying elements mapping to a 4.1 kb Plcz1 promoter fragment. When broad ectopic PLCZ1 expression was forced in independent transgenic lines, they initially appeared healthy. Their oocytes underwent unperturbed meiotic maturation to mII but subsequently exhibited autonomous intracellular free calcium oscillations, second polar body extrusion, pronucleus formation and parthenogenetic development. Transfer of transgenic cumulus cell nuclei into wild-type oocytes induced activation and development, demonstrating a direct effect of PLCZ1 analogous to fertilisation. Whereas Plcz1 transgenic males remained largely asymptomatic, females developed abdominal swellings caused by benign ovarian teratomas that were under-represented for paternally- and placentally-expressed transcripts. Plcz1 was not overexpressed in the ovaries of LT/Sv or in human germline ovarian tumours. The narrow spectrum of PLCZ1 activity indicates that it is modulated by tissue-restricted accessory factors. This work characterises a novel model in which parthenogenesis and tumourigenesis follow full meiotic maturation and are linked to fertilisation by PLCZ1.


Assuntos
Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Partenogênese , Fosfoinositídeo Fosfolipase C/metabolismo , Espermatozoides/metabolismo , Animais , Sequência de Bases , Transformação Celular Neoplásica , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Histona-Lisina N-Metiltransferase , Humanos , Masculino , Meiose , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Proteína de Leucina Linfoide-Mieloide/metabolismo , Oócitos/citologia , Oócitos/metabolismo , Neoplasias Ovarianas/genética , Fosfoinositídeo Fosfolipase C/química , Fosfoinositídeo Fosfolipase C/genética , Sensibilidade e Especificidade
15.
Sci Total Environ ; 381(1-3): 233-42, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17477955

RESUMO

Dechlorination of PCP has been observed previously under anaerobic condition in paddy soil. However, there is poor information about the dechlorination pathway of PCP and the microbial community associated with the PCP dechlorination in paddy soil. In this study, an anaerobic microbial community dechlorinating PCP was enriched by serial transfers from a paddy soil using a medium containing PCP, lactate and the steam-sterilized paddy soil. The enriched microbial community dechlorinated PCP completely to phenol under the anaerobic condition by a dechlorinating pathway as follows; PCP-->2,3,4,5-tetrachlorophenol-->3,4,5-trichlorophenol-->3,5-dichlorophenol-->3-chlorophenol-->phenol. Intermediate products such as 3-chlorophenol were not accumulated, which were immediately dechlorinated to phenol. The enriched microbial community was characterized physiologically by testing the effects of electron donors and electron acceptors on the dechlorinating activity. The dechlorinating activity was promoted with lactate, pyruvate, and hydrogen as electron donors but not with acetate. Electron acceptors, nitrate and sulphate, inhibited the dechlorinating activity competitively but not iron (III). The microbial group associated with the anaerobic dechlorination was characterized by the effect of specific inhibitors on the PCP dechlorination. Effects of specific metabolic inhibitors and antibiotics indicated the involvement of Gram-positive spore-forming bacteria with the PCP dechlorinating activity, which was represented as bacteria of phylum Firmicutes. The structure of the microbial community was characterized by fluorescence in situ hybridization, quinone profiling, and PCR-DGGE (denaturing gel gradient electrophoresis). The combined results indicated the predominance of Clostridium species of phylum Firmicutes in the microbial community. Desulfitobacterium spp. known as anaerobic Gram-positive spore-forming bacteria dechlorinating PCP were not detected by PCR using a specific primer set. These indicated a probable presence of novel anaerobic Gram-positive spore-forming bacteria dechlorinating PCP in the microbial community.


Assuntos
Desulfitobacterium/metabolismo , Pentaclorofenol/metabolismo , Microbiologia do Solo , Biodegradação Ambiental , Cloro/metabolismo , Desulfitobacterium/classificação , Desulfitobacterium/isolamento & purificação , Eletroforese , Hibridização in Situ Fluorescente , Fenóis/metabolismo , Filogenia , Reação em Cadeia da Polimerase , Quinonas/metabolismo
16.
FEBS Lett ; 579(10): 2058-64, 2005 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-15811318

RESUMO

Galectin-9 and galectin-8, members of beta-galactoside-binding animal lectin family, are promising agents for the treatment of immune-related and neoplastic diseases. The proteins consist of two carbohydrate recognition domains joined by a linker peptide, which is highly susceptible to proteolysis. To increase protease resistance, we prepared mutant proteins by serial truncation of the linker peptide. As a result, mutant forms lacking the entire linker peptide were found to be highly stable against proteolysis and retained their biological activities. These mutant proteins might be useful tools for analyzing the biological functions and evaluating the therapeutic potential of galectin-9 and galectin-8.


Assuntos
Galectinas/metabolismo , Peptídeo Hidrolases/metabolismo , Sequências de Repetição em Tandem , Sequência de Bases , DNA Complementar , Galectinas/genética
17.
Dev Biol ; 274(2): 370-83, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15385165

RESUMO

Mammalian sperm-borne oocyte activating factor (SOAF) induces oocyte activation from a compartment that engages the oocyte cytoplasm, but it is not known how. A SOAF-containing extract (SE) was solubilized from the submembrane perinuclear matrix, a domain that enters the egg. SE initiated activation sufficient for full development. Microinjection coupled to tandem mass spectrometry enabled functional correlation profiling of fractionated SE without a priori assumptions about its chemical nature. Phospholipase C-zeta (PLCzeta) correlated absolutely with activating ability. Immunoblotting confirmed this and showed that the perinuclear matrix is the major site of 72-kDa PLCzeta. Oocyte activation was efficiently induced by 1.25 fg of sperm PLCzeta, corresponding to a fraction of one sperm equivalent (approximately 0.03). Immunofluorescence microscopy localized sperm head PLCzeta to a post-acrosomal region that becomes rapidly exposed to the ooplasm following gamete fusion. This multifaceted approach suggests a mechanism by which PLCzeta originates from an oocyte-penetrating assembly--the sperm perinuclear matrix--to induce mammalian oocyte activation at fertilization.


Assuntos
Oócitos/fisiologia , Interações Espermatozoide-Óvulo , Espermatozoides/enzimologia , Fosfolipases Tipo C/metabolismo , Animais , Fracionamento Celular , Feminino , Fertilização/fisiologia , Humanos , Masculino , Camundongos , Microinjeções , Dados de Sequência Molecular , Matriz Nuclear/química , Matriz Nuclear/enzimologia , Oócitos/citologia , Fosfoinositídeo Fosfolipase C , Espermatozoides/química , Espermatozoides/citologia , Suínos , Fosfolipases Tipo C/química , Fosfolipases Tipo C/genética
18.
J Immunol ; 170(7): 3631-6, 2003 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-12646627

RESUMO

Galectin-9 (Gal-9) induced the apoptosis of not only T cell lines but also of other types of cell lines in a dose- and time-dependent manner. The apoptosis was suppressed by lactose, but not by sucrose, indicating that beta-galactoside binding is essential for Gal-9-induced apoptosis. Moreover, Gal-9 required at least 60 min of Gal-9 binding and possibly de novo protein synthesis to mediate the apoptosis. We also assessed the apoptosis of peripheral blood T cells by Gal-9. Apoptosis was induced in both activated CD4(+) and CD8(+) T cells, but the former were more susceptible than the latter. A pan-caspase inhibitor (Z-VAD-FMK) inhibited Gal-9-induced apoptosis. Furthermore, a caspase-1 inhibitor (Z-YVAD-FMK), but not others such as Z-IETD-FMK (caspase-8 inhibitor), Z-LEHD-FMK (caspase-9 inhibitor), and Z-AEVD-FMK (caspase-10 inhibitor), inhibited Gal-9-induced apoptosis. We also found that a calpain inhibitor (Z-LLY-FMK) suppresses Gal-9-induced apoptosis, that Gal-9 induces calcium (Ca(2+)) influx, and that either the intracellular Ca(2+) chelator BAPTA-AM or an inositol trisphosphate inhibitor 2-aminoethoxydiphenyl borate inhibits Gal-9-induced apoptosis. These results suggest that Gal-9 induces apoptosis via the Ca(2+)-calpain-caspase-1 pathway, and that Gal-9 plays a role in immunomodulation of T cell-mediated immune responses.


Assuntos
Apoptose/fisiologia , Sinalização do Cálcio , Calpaína/fisiologia , Caspase 1/fisiologia , Galectinas/fisiologia , Adjuvantes Imunológicos/fisiologia , Clorometilcetonas de Aminoácidos/farmacologia , Linfócitos B/citologia , Linfócitos B/enzimologia , Linfócitos B/fisiologia , Cálcio/metabolismo , Cálcio/fisiologia , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/imunologia , Inibidores de Caspase , Inibidores de Cisteína Proteinase/farmacologia , Relação Dose-Resposta Imunológica , Células HL-60 , Humanos , Células Jurkat , Monócitos/citologia , Monócitos/enzimologia , Monócitos/fisiologia , Células Mieloides/citologia , Células Mieloides/enzimologia , Células Mieloides/fisiologia , Oligopeptídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Linfócitos T/citologia , Linfócitos T/enzimologia , Linfócitos T/fisiologia , Células Tumorais Cultivadas
19.
J Vet Med Sci ; 64(1): 63-5, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11853148

RESUMO

The effects of non-specific immunotherapy with anti-allergic peptides extracted from the urine of human allergic patients (MS-antigen), in two dogs with allergic dermatitis (AD) have been described. Clinically, severe pruritus accompanied by secondary bacterial pyoderma did not respond to conventional therapy with systemic antibiotics. The first clinical change appeared as a significant reduction in pruritus within 3 months, around the time of the 15th injection in both cases. The clinical condition was stabilized after 5 months, allowing the gradual withdrawal of concurrent therapies and an increase of injection intervals. The correlation between the results of intradermal skin tests before and after treatment and the improvement of clinical signs was not obvious.


Assuntos
Antígenos/uso terapêutico , Dermatite Atópica/veterinária , Doenças do Cão/imunologia , Imunoterapia/veterinária , Peptídeos/imunologia , Animais , Dermatite Atópica/imunologia , Cães , Humanos , Masculino , Prurido/imunologia , Prurido/veterinária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA