RESUMO
ß decay of proton-rich nuclei plays an important role in exploring isospin mixing. The ß decay of ^{26}P at the proton drip line is studied using double-sided silicon strip detectors operating in conjunction with high-purity germanium detectors. The T=2 isobaric analog state (IAS) at 13 055 keV and two new high-lying states at 13 380 and 11 912 keV in ^{26}Si are unambiguously identified through ß-delayed two-proton emission (ß2p). Angular correlations of two protons emitted from ^{26}Si excited states populated by ^{26}P ß decay are measured, which suggests that the two protons are emitted mainly sequentially. We report the first observation of a strongly isospin-mixed doublet that deexcites mainly via two-proton decay. The isospin mixing matrix element between the ^{26}Si IAS and the nearby 13 380-keV state is determined to be 130(21) keV, and this result represents the strongest mixing, highest excitation energy, and largest level spacing of a doublet ever observed in ß-decay experiments.
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To explore effects of the sDR5-Fc fusion protein on ulcerative colitis of infant mice via the TRAIL-DR5 pathway, 50 female mice were randomly divided into 5 groups, i.e., control group (group A), dextran sulfate sodium group (group B), hIgG group (group C), 10 mg/kg sDR5-Fc group (group D), and 20 mg/ kg sDR5-Fc group (group E). The acute ulcerative colitis models were established. The weights and disease activity index (DAI) of each group were monitored daily. In addition, the pathological changes of colon tissues were observed by Hematoxylin-Eosin staining. The number of macrophages in colon tissues was detected by immunohistochemistry assay. Changes in the expression of inflammatory factors in colon tissues were detected by quantitative real-time polymerase chain reaction (PCR). Lipopolysaccharide (LPS) of different concentrations was utilized alone or in combination with TRAIL to stimulate the NCM460 cells. The activation of NLRP3 inflammasomes was detected by Western blot. The apoptosis of NCM460 cells was detected by flow cytometry. The results showed that in groups B and C, the body weights decreased, the DAI increased, the colon epithelial cells were injured, the inflammatory cells were infiltrated, and the macrophages in colon tissues increased significantly. In groups D and E, the body weights increased, the DAI decreased, the inflammation was significantly improved, the macrophages decreased significantly, and the gene expression levels of NLRP3, Caspase-1, and IL-1ß decreased significantly. Thus, sDR5-Fc could inhibit the activation of NLRP3 inflammasomes induced by TRAIL, thereby decreasing the apoptosis of NCM460 cells. In conclusion, the sDR5-Fc fusion protein could block the TRAIL-DR5 pathway to reduce the expression of NLRP3 inflammasomes, thereby improving ulcerative colitis.
Assuntos
Colite Ulcerativa/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteínas Recombinantes de Fusão/uso terapêutico , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Animais , Apoptose , Colite Ulcerativa/induzido quimicamente , Sulfato de Dextrana , Feminino , Inflamassomos , Macrófagos/citologia , Camundongos , Distribuição AleatóriaRESUMO
The phospholipase C (PLC) is a family of kinases that hydrolyze phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] to generate two second messengers, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG), which stimulate distinct downstream signaling. Recently, it has been reported that PLC signaling is activated by multiple viruses for efficient replication and the virus-induced inflammatory response. In this study, we demonstrated that PLC-specific inhibitor U73122 strongly suppressed porcine reproductive and respiratory syndrome virus (PRRSV) productive infection in cell cultures. The inhibitor affected both viral post-binding cell entry and post-entry processes. The virus infection led to an early transient activation of PLCγ-1 at 0.5 h post-infection (hpi), and sustained event at a stage from 4 to 16 hpi in MARC-145 cells. In addition, U73122 inhibited the activation of p38 MAPK signaling stimulated by PRRSV infection, suggesting that PLC signaling may be associated with the virus infection-induced inflammatory response. Taken together, these studies suggested that PLC signaling played an important role in PRRSV infection or pathogenesis. Keywords: PRRSV; U73122; phospholipase C; PLCγ-1.
Assuntos
Síndrome Respiratória e Reprodutiva Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Fosfolipases Tipo C , Animais , Linhagem Celular , Estrenos/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Síndrome Respiratória e Reprodutiva Suína/fisiopatologia , Pirrolidinonas/farmacologia , Transdução de Sinais , Suínos , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipases Tipo C/fisiologia , Internalização do Vírus/efeitos dos fármacosRESUMO
OBJECTIVE: To evaluate the practical value of AutoCAD in quantitative analysis of corneal subbasal epithelial nerves with different degrees of dry eye. METHODS: Ninety patients were divided into groups of mild, moderate, and severe dry eye, 30 patients (60 eyes) in each group. And 30 healthy volunteers were recruited as the normal control group. Confocal microscopy was used to observe the length of the subbasal epithelial nerve plexus. The images were analyzed by AutoCAD software to determine the density (mm/mm(2)), the number of branches, and the curvature score of the subbasal epithelial nerves. These data of patients with dry eye and the controls were statistically compared, by analysis of variance(ANOV). RESULTS: By AutoCAD software, quantitative analysis of the corneal subbasal epithelial nerves was successfully performed. The nerve density in the patients with mild dry eye[(16.70±3.43) mm/mm(2)] was not significantly different from the controls[(15.87 ± 2.75) mm/mm(2)] (P=0.880), but the number of nerval branches 13.43±2.46 and the curvature 3.10±0.80 increased significantly (P<0.001). The nerve density in the patients with moderate and severe dry eye was significantly different from that in the normal control group (F=114.739, P<0.001). The neural density was significantly lower in the patients with severe dry eye than the controls, but there was no significant difference in the curvature scores between the two groups (P= 0.557). CONCLUSIONS: AutoCAD software is useful in the quantitative analysis of corneal nerve images under a confocal microscope. The corneal subbasal epithelial nerve density, the number of branches, and the curvature of the nerves are related to the degree of dry eye, and may be used as clinical indicators.
Assuntos
Córnea/inervação , Síndromes do Olho Seco , Microscopia Confocal/métodos , Software , Análise de Variância , Estudos de Casos e Controles , HumanosRESUMO
African swine fever virus (ASFV) causes feverous and hemorrhagic disease of domestic pigs and European wild boars with high mortality, yet no commercial vaccine is currently available. Several ASFV strains with natural deletion or gene-targeted knockout of multiple MGF360 and MGF505 genes are attenuated in vitro and in vivo, and can offer full protection against homologous challenge. However, the mechanisms underlying the protection are not fully understood. This study aims to investigate the effects of MGF360-12L of ASFV-SY18 on the cGAS-STING signaling pathway and explore the potential mechanisms. We identified that ASFV-SY18 MGF360-12L could inhibit cGAS-STING, TBK1, or IRF3-5D-stimulated IFN-ß expression and ISRE activation. Specifically, MGF360-12L inhibits both the activation of PRD(III-I) in a dose-dependent manner, and suppresses the exogenous expression of TBK1 and IRF3-5D. MGF360-12L could block NF-κB activation induced by overexpression of cGAS-STING, TBK1, IKKß. Downstream of the IFN-ß signaling, MGF360-12L blocks the ISRE promoter activation by reducing total protein level of IRF9. Moreover, MGF360-12L protein can inhibit IFN-ß-mediated antiviral effects. In conclusion, our findings suggest that MGF360-12L is a multifunctional immune-evasion protein that inhibits both the expression and effect of IFN-ß, which could partially explain the attenuation of relevant gene-deleted ASFV strains, and shed light on the development of efficient ASFV live attenuated vaccines in the future.
Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Interferon Tipo I , Doenças dos Suínos , Suínos , Animais , Vírus da Febre Suína Africana/genética , NF-kappa B/genética , NF-kappa B/metabolismo , Janus Quinases/metabolismo , Transdução de Sinais , Proteínas Virais/genética , Fatores de Transcrição STAT/metabolismo , Sus scrofa/metabolismo , Interferon Tipo I/metabolismo , Nucleotidiltransferases/metabolismoRESUMO
CC chemokine ligand 21 (CCL21) is a known attractant for CCR7-positive (CCR7+) cells, but its additional role in the immunogenicity of CCR7+ cells remains poorly understood. This study explored the effects of CCL21-CCR7 ligation on cancer immunogenicity and related antitumor immune response, in the presence and absence of mitomycin C (MMC) treatment. CCL21-CCR7 binding upregulated human leukocyte antigen class I-restricted tumor antigen presentation with increased expression of human leukocyte antigen class I and transporter associated with antigen processing-1. In addition, CCL21 restrained the tumor-derived immunosuppressive factors FasL and transforming growth factor-ß. Consequently, CCL21 facilitated cancer-educated lymphocytes reaction in vitro. In the tumor-bearing mouse, CCL21 inhibited tumor growth and prolonged mouse survival via lymphocytes, especially in CCR7+ cancer cells. Furthermore, Toll-like receptor 2 activation of lymphocytes assisted the tumor-suppression functions of CCL21, in vitro and in vivo. This study implies that CCL21 improved the immunogenicity of the CCR7+ breast cancer cell line even with MMC treatment and triggered antitumor response by lymphocytes. These findings provide a new insight into the research and application of CCL21-associated antitumor response.
Assuntos
Neoplasias da Mama/imunologia , Quimiocina CCL21/fisiologia , Receptores CCR7/fisiologia , Linfócitos T/imunologia , Receptor 2 Toll-Like/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Apresentação de Antígeno , Western Blotting , Neoplasias da Mama/tratamento farmacológico , Ensaio de Imunoadsorção Enzimática , Proteína Ligante Fas/genética , Proteína Ligante Fas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Ligantes , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitomicina/farmacologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Células Tumorais CultivadasRESUMO
The bursa of Fabricius (BF) is a central immune organ in birds, and some peptides from chicken BF have demonstrated important immune functions. Here, a new 626.27 Da pentapeptide, Bursopentin (BP5, Cys-Lys-Arg-Val-Tyr) was isolated and purified by reverse-phase high-performance liquid chromatography. In this study, we examined the effects of BP5 on antigen-specific immune response in BALB/c mice sensitized with inactivated avian influenza virus (AIV) [A/Duck/Jiangsu/NJ08/05 (AIV H9N2 subtype)]. The results suggested that BP5 enhanced anti-hemagglutinin antibody (IgG, the isotypes IgG1 and IgG2a) production, induced both of Th1- (IL-2 and IFN-γ) and Th2-type (IL-4 and -10) cytokines, increased proliferations of splenic lymphocyte subsets CD4+ T cells (CD3+CD4+), CD8+ T cells (CD3+CD8+) and B cells, and enhanced cytotoxic T-lymphocyte activity of the activated splenocytes against NIH3T3 cells. The effects of BP5 on the proliferation of isolated T- and/or B-cell populations of BALB/c mice were assessed, and the data suggested that BP5 promoted spleen lymphocyte proliferation by activating B cells directly and T cells indirectly. Further analysis revealed that B-lymphocyte proliferation induced by BP5 is mediated by reactive oxygen species generated from thiol auto-oxidation of BP5. Furthermore, our data indicated that protein kinase C, mitogen-activated protein kinase, and nuclear factor kappa B are involved in the signal transductions during the BP5-induced B lymphocyte proliferation. This study indicates that BP5 could be a potential immunomodulator for future immuno-pharmacological use.
Assuntos
Bolsa de Fabricius/química , Galinhas/imunologia , Fatores Imunológicos/imunologia , Oligopeptídeos/imunologia , Animais , Bolsa de Fabricius/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Citocinas/imunologia , Feminino , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/uso terapêutico , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , Influenza Aviária/tratamento farmacológico , Influenza Aviária/imunologia , Influenza Aviária/virologia , Camundongos , Camundongos Endogâmicos BALB C , Células NIH 3T3 , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/uso terapêutico , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologiaRESUMO
In this study, polyvinyl alcohol (PVA) nanofibrous membranes containing silver nanoparticles (Ag NPs) were successfully fabricated by the combination of electrospinning and a green reduction approach. Through the electrospinning technique, uniform and smooth nanofibres can be obtained, and the Ag NPs with a narrow size distributions are well dispersed in PVA nanofibres. The investigation indicates that the mass ratio of reductant tea polyphenols and AgNO3 play a crucial role in controlling the size of the Ag NPs. More importantly, multi-layered fabrics with a layer of PVA/Ag NP nanofibrous membrane layered onto cotton substrates were developed and applied to shoe insoles. The fabricated shoe insoles with functionalized PVA nanofibres exhibit remarkable antimicrobial activity against both E. coli and S. aureus (i.e. antibacterial rate > 99%). The creation of such an encouraging fabric could establish a new optimization methodology for producing nanoengineered functional textiles.
RESUMO
Canine parvovirus (CPV) causes acute gastroenteritis in domestic dogs, cats, and several wild carnivore species. In this study, the full-length VP2 gene of 36 CPV isolates from dogs and cats infected between 2016 and 2017 in Beijing was sequenced and analyzed. The results showed that, in dogs, the new CPV-2a strain was the predominant variant (n = 18; 50%), followed by the new CPV-2b (n = 6; 16.7%) and CPV-2c (n = 3; 8.3%) strains, whereas, among cats, the predominant strain was still CPV-2 (n = 9; 25%). One new CPV-2a strain, 20170320-BJ-11, and two CPV-2c strains, 20160810-BJ-81 and 20170322-BJ-26, were isolated and used to perform experimental infections. Multiple organs of beagles that died tested PCR positive for CPV, and characteristic histopathological lesions were observed in organs, including the liver, spleen, lungs, kidneys, small intestines, and lymph nodes. Experimental infections showed that the isolates from the epidemic caused high morbidity in beagles, indicating their virulence in animals and suggesting the need to further monitor evolution of CPV in China.
Assuntos
Proteínas do Capsídeo/genética , Doenças do Gato/virologia , Doenças do Cão/virologia , Infecções por Parvoviridae/veterinária , Parvovirus Canino/genética , Animais , Doenças do Gato/epidemiologia , Gatos , Doenças do Cão/epidemiologia , Cães , Variação Genética , Genoma Viral , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Parvovirus Canino/classificação , FilogeniaRESUMO
Type 1 diabetes (T1D) is due to a loss of immune tolerance to islet antigens, such as glutamic acid decarboxylase 65 (GAD65), for which islet transplantation is a promising therapy. Therefore, the generation of tolerance aiming at both alloantigen and GAD65 will help therapeutic intervention greatly in T1D. In this study, we tested the effect of programmed death-1 ligands (PD-L1)-transfected dendritic cells (DC) loaded with GAD65 on the alloresponse and GAD65-reactive lymphocyte response. The DC2.4 cell line was transfected with PD-L1 and co-cultured with GAD65. BALB-c mice were primed, respectively, by intraperitoneal injection with GAD65, PD-L1-transfected- or non-transfected DC (PD-L1/DC or DC), and PD-L1-transfected- or non-transfected DC loaded with GAD65 (PD-L1/DC/GAD65 or DC/GAD65). Splenocytes of treated mice were isolated and restimulated in vitro with GAD65 or the various DC populations above being used as stimulators, respectively. In the mixed lymphocyte reaction, DC/GAD65 were able to stimulate both allogeneic and GAD65-reactive lymphocytes. However, PD-L1/DC/GAD65 were poorer than DC/GAD65 at activating the GAD65-reactive lymphocyte response. Further, although PD-L1/DC could inhibit the alloresponse, PD-L1/DC/GAD65 were more effective at down-regulating the GAD65-reactive lymphocyte response. More importantly, PD-L1/DC/GAD65-primed lymphocytes exhibited the weakest proliferation when again restimulated in vitro by PD-L1/DC/GAD65. Additionally, PD-L1/DC/GAD65 down-regulated interferon-gamma and up-regulated interleukin-10 production by activated lymphocytes. Therefore, combined stimulation in vivo and in vitro by PD-L1/DC/GAD65 could inhibit both the alloresponse and the GAD65-reactive lymphocyte response, which may contribute to controlling diabetes and islet transplant rejection.
Assuntos
Antígenos CD/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Células Dendríticas/imunologia , Glutamato Descarboxilase/metabolismo , Transferência Adotiva , Animais , Antígenos CD/genética , Proteínas Reguladoras de Apoptose/genética , Linhagem Celular , Proliferação de Células , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Endocitose , Tolerância Imunológica , Interferon gama/análise , Interleucina-10/análise , Isoantígenos/imunologia , Ligantes , Ativação Linfocitária , Linfócitos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Receptor de Morte Celular Programada 1 , Transfecção/métodos , TransgenesRESUMO
An extracellular beta-xylosidase from the thermophilic fungus Paecilomyces thermophila J18 was purified 31.9-fold to homogeneity with a recovery yield of 2.27% from the cell-free culture supernatant. It appeared as a single protein band on SDS-PAGE with a molecular mass of approx 53.5 kDa. The molecular mass of beta-xylosidase was 51.8 kDa determined by Superdex 75 gel filtration. The enzyme was a glycoprotein with a carbohydrate content of 61.5%. It exhibited an optimal activity at 55 degrees C and pH 6.5, respectively. The enzyme was stable in the range of pH 6.0-9.0 and at 55 degrees C. The purified enzyme hydrolyzed xylobiose and higher xylooligosaccharides but was inactive against xylan substrates. It released xylose from xylooligosaccharides with a degree of polymerization ranging between 2 and 5. The rate of xylose released from xylooligosaccharides by the purified enzyme increased with increasing chain length. It had a K(m) of 4.3mM for p-nitrophenol-beta-d-xylopyranoside and was competitively inhibited by xylose with a K(i) value of 139 mM. Release of reducing sugars from xylans by a purified xylanase produced by the same organism increased markedly in the presence of beta-xylosidase. During 24-hour hydrolysis, the amounts of reducing sugar released in the presence of added beta-xylosidase were about 1.5-1.73 times that of the reaction employing the xylanase alone. This is the first report on the purification and characterization of a beta-xylosidase from Paecilomyces thermophila.
Assuntos
Endo-1,4-beta-Xilanases/metabolismo , Paecilomyces/enzimologia , Xilose/metabolismo , Xilosidases/metabolismo , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Paecilomyces/crescimento & desenvolvimento , Especificidade por Substrato , Triticum , Xilosidases/isolamento & purificaçãoRESUMO
Endoplasmic reticulum stress-mediated apoptosis plays an important role in the destruction of pancreatic beta-cell, and contributes to the development of type 1 diabetes. The chaperone molecule, glucose regulated proteins 78 (GRP78), is required to maintain ER function during toxic insults. In this study, we investigated the effect of GRP78 on the beta-cell apoptosis. We first measured GRP78 protein expression in different phase of streptozotocin-affected beta-cell by immunoblotting analysis. An insulinoma cell line, NIT-1, transfected with GRP78 was established, named NIT-GRP78, and used to study apoptosis, which was induced by streptozotocin or inflammatory cytokines. Apoptosis of NIT-1 or NIT-GRP78 cells was detected by flow cytometry, the transcription of C/EBP homologous protein (CHOP) was monitored by real-time PCR, the concentration of nitric oxide and the activity of superoxide dismutase were measured by colorimetric method. We found that, in comparison to NIT-1 cells, NIT-GRP78 cells responded to the streptozotocin or cytokines treatments with decreased concentration of nitric oxide, but increased activity of superoxide dismutase. In addition, the level of CHOP was also decreased in the NIT-GRP78 cells, which may mediate the resistance of the GRP78 overexpressed NIT-1 cells from apoptosis. Finally, we found that NIT-GRP78 cells were also more resistant than NIT-1 cells to cytotoxic T lymphocyte (CTL) specific killing detected by flow cytometry through target cells expressing green fluorescent protein cultured with effector cells and finally stained with propidium iodide. The data suggest that modulating GRP78 expression could be useful in preventing pancreatic beta-cell from the immunological destruction in type 1 diabetes individuals.
Assuntos
Citocinas/farmacologia , Proteínas de Choque Térmico/metabolismo , Insulinoma/patologia , Chaperonas Moleculares/metabolismo , Estreptozocina/farmacologia , Linfócitos T Citotóxicos/metabolismo , Animais , Morte Celular/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Proteínas de Fluorescência Verde/metabolismo , Insulinoma/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Objective:The aim of this study is to investigate the effect of gonadotropin releasing hormone (GnRH) on suppressing cell viability, apoptosis, migrationg and invationg of human nasopharyngeal carcinoma cells CNE2. Method:Nasopharyngeal carcinoma tissues and postnasal catarrh tissues were collected, the expression of GnRH positive cells and GnRH mRNA were detected by immunohistochemical staining and qRT-PCR. The human nasopharyngeal carcinoma CNE2 cells and immortalized nasopharyngeal epithelial cell line NP69 were cultured in vitro, and the expression of GnRH positive cells and GnRH mRNA were detected by immunohistochemical staining and qRT-PCR. The CNE2 cells were treated with GnRH with various concentrations 0 (Blank group), 10⻲, 10⻹, 10° nmol/L. The effects of GnRH on the viability, apoptosis, migration and invasion of CNE2 cells were detected by cell Counting Kit (CCK-8), flow cytometry, wound healing assay and transwell chamber assay in vitro. Result:The expression of GnRH positive cells and GnRH mRNA in nasopharyngeal carcinoma tissues were markedly down regulated than postnasal catarrh tissues (P<0.05). The expression of GnRH positive cells and GnRH mRNA in CNE2 cells were markedly down regulated than NP69 cells (P<0.05). Compared with blank group, GnRH can significantly inhibite the cell viability cells, apoptosis, migration and invasive ability (P<0.05 or P<0.01). Conclusion:GnRH significantly inhibited the cell viability, apoptosis, migration and invasive ability of CNE2 cells.
Assuntos
Proliferação de Células/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/farmacologia , MicroRNAs/genética , Neoplasias Nasofaríngeas/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinoma , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/genética , Humanos , MicroRNAs/metabolismo , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patologia , RNA Mensageiro , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In the present study, polymerase chain reaction (PCR) was conducted to determine mtDNA(4834) deletion, and myocardial ultrastructure was visualized by electron microscope to see whether intermittent hypoxia (high altitude) adaptation exerts some action on mitochondria against ischemia/reperfusion injury. Myocardial ischemia/reperfusion in isolated perfused rat hearts induced severe damage to the ultrastructure of myocardial mitochondria and mtDNA4834 deletion down to 87.5% of normoxia rats. After the rats were exposed to intermittent hypoxia (5000 m; 6 h/d for 28 d), the myocardial structure was well reserved and mtDNA(4834) deletion dropped to 28.57%of control (P<0.05). It is suggested that intermittent hypoxia adaptation prevents mtDNA deletion, and preserves normal structure of mitochondria, which would be beneficial to the maintenance of normal mitochondrial function, and increases tolerance of myocardium against ischemia/reperfusion injury.
Assuntos
DNA Mitocondrial/genética , Precondicionamento Isquêmico Miocárdico , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/ultraestrutura , Animais , Sequência de Bases , Dano ao DNA , Hipóxia , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
The purpose of the study was to observe the effects of intermittent hypoxia exposure (IH) on the arrhythmia and antioxidation with ligation of coronary artery of rat heart together with measuring SOD (superoxide dismutase) and MDA (malondialdehyde) in myocardium. Comparison with continued hypoxia exposure was also made. The results obtained are as follows. (1) Arrhythmia scores of ischemic arrhythmia and reperfusion arrhythmia observed in the rats treated with IH 28-day (IH28) and 42-day (IH42), one week (IH28-1W) and two weeks (IH28-2W) after 28-day IH, as well as in those with continued hypoxia 28-day (CH28) and 42-day (CH42), were significantly lower than controls. (2) SOD in IH28, IH42, CH28, CH42, IH28-1W, IH28-2W and three weeks after 28-day IH were significantly higher than controls; MDA in IH14, IH28, IH42, CH28, CH42, IH28-1W and IH28-2W were significantly lower than controls. It is suggested that IH for 28 or 42 days has some definite antiarrhythmic effect against ischemia and reperfusion, which was related to the strength of antioxidation in myocardium. The antiarrhythmic effects occurred gradually after 14 days IH and persisted for about two weeks after 28 days IH.
Assuntos
Arritmias Cardíacas/prevenção & controle , Hipóxia/fisiopatologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Superóxido Dismutase/metabolismo , Animais , Precondicionamento Isquêmico Miocárdico , Masculino , Malondialdeído/metabolismo , Miocárdio/citologia , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane fluidity induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However, the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding isotypic and idiotypic determinants of IgM on the cell membrane.
Assuntos
Leucemia de Células B/metabolismo , Fluidez de Membrana , Tonsila Palatina/citologia , Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Monoclonais/imunologia , Células Cultivadas , Epitopos/imunologia , Polarização de Fluorescência , Humanos , Imunoglobulina M/imunologia , Leucemia de Células B/imunologia , Células Tumorais CultivadasRESUMO
In this study, the anti-idiotypic and anti-isotypic antibodies (McAbs) against IgM of the Patient with B chronic lymphocytic leukemia (B-CLL) were purified from hybridoma ascites by n-Octoic acid precipitation method. The purified McAbs have high purify and high antibody activity as evidenced by immunoelectrophoresis, SDS-PAGE and ELISA. Relative affinity of 11 McAbs was measured by using indirect ELISA and double antibody sandwich ELISA method. It was found that relative affinity of various McAbs to the same antigen was different. 11 McAbs could be divided into two groups by analysing their 50% maximum binding. The relative affinity of 4 McAbs in the culture supernatants was consistent with that of McAbs in the purified ascites. Our experimental results provide an important basis for rational application of these McAbs.
Assuntos
Anticorpos Anti-Idiotípicos/isolamento & purificação , Anticorpos Monoclonais/isolamento & purificação , Leucemia Linfocítica Crônica de Células B/imunologia , Afinidade de Anticorpos , Ensaio de Imunoadsorção Enzimática , Humanos , Hibridomas/metabolismo , Imunoglobulina M/imunologiaRESUMO
The proliferation of splenocytes from healthy adults was induced by anti-CD3 McAb, PHA and IL-2. The proliferative capability and anti-tumor activity as well as phenotypes of the splenocytes cultured in different medium systems were studied. The results showed that anti-CD3 McAb and PHA not only enhanced the proliferation of splenocytes induced by IL-2, but also produced synergism if used simultaneously. The expressions of CD4 and Tac of cellular surface markers were increased after splenocytes were induced by anti-CD3 McAb and PHA. The results of anti-tumor activity of LAK cells suggested that PHA had the capability to promote anti-tumor activity of LAK cells by both direct and indirect pathways, but anti-CD3 McAb indirectly promoted anti-tumor activity of LAK cells by enhancing splenocyte proliferation.