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1.
Small ; 20(11): e2309454, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38098368

RESUMO

The optimal treatment for tracheal tumors necessitates sequential tumor elimination and tracheal cartilage reconstruction. This study introduces an innovative inorganic nanosheet, MnO2 /PDA@Cu, comprising manganese dioxide (MnO2 ) loaded with copper ions (Cu) through in situ polymerization using polydopamine (PDA) as an intermediary. Additionally, a specialized methacrylic anhydride modified decellularized cartilage matrix (MDC) hydrogel with chondrogenic effects is developed by modifying a decellularized cartilage matrix with methacrylic anhydride. The MnO2 /PDA@Cu nanosheet is encapsulated within MDC-derived microneedles, creating a photothermal-controllable MnO2 /PDA@Cu-MDC microneedle. Effectiveness evaluation involved deep insertion of the MnO2 /PDA@Cu-MDC microneedle into tracheal orthotopic tumor in a murine model. Under 808 nm near-infrared irradiation, facilitated by PDA, the microneedle exhibited rapid overheating, efficiently eliminating tumors. PDA's photothermal effects triggered controlled MnO2 and Cu release. The MnO2 nanosheet acted as a potent inorganic nanoenzyme, scavenging reactive oxygen species for an antioxidant effect, while Cu facilitated angiogenesis. This intervention enhanced blood supply at the tumor excision site, promoting stem cell enrichment and nutrient provision. The MDC hydrogel played a pivotal role in creating a chondrogenic niche, fostering stem cells to secrete cartilaginous matrix. In conclusion, the MnO2 /PDA@Cu-MDC microneedle is a versatile platform with photothermal control, sequentially combining antitumor, antioxidant, pro-angiogenic, and chondrogenic activities to orchestrate precise tracheal tumor eradication and cartilage regeneration.


Assuntos
Nanopartículas , Neoplasias , Neoplasias da Traqueia , Humanos , Camundongos , Animais , Antioxidantes , Compostos de Manganês , Óxidos , Neoplasias/patologia , Cartilagem , Hidrogéis , Anidridos
2.
J Dairy Sci ; 105(2): 940-949, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955252

RESUMO

ß-Galactosidase is one of the most important enzymes used in dairy processing. It converts lactose into glucose and galactose, and also catalyzes galactose to form galactooligosaccharides (GOS), so-called prebiotics. However, most of the ß-galactosidases from the starter cultures have low transgalactosylation activities, the process that results in galactose accumulation in yogurt. Here, a site-directed mutation strategy was attempted, to genetically modify ß-galactosidase from Streptococcus thermophilus. Out of 28 Strep. thermophilus strains, a ß-galactosidase gene named bgaQ, encoded for high ß-galactosidase hydrolysis activity (BgaQ), was cloned from the strain Strep. thermophilus SDMCC050237. It was 3,081 bp in size, with 1,027 deduced amino acid residuals, which belonged to the GH2 family. After replacing the Tyr801 and Pro802 around the active sites of BgaQ with His801 and Gly802, the GOS synthesis of the generated mutant protein BgaQ-8012 increased from 20.5% to 26.7% at 5% lactose, and no hydrolysis activity altered obviously. Subsequently, the purified BgaQ or BgaQ-8012 was added to sterilized milk inoculated with 2 starters from Strep. thermophilus SDMCC050237 and Lactobacillus delbrueckii ssp. bulgaricus ATCC11842. The GOS yields with added BgaQ or BgaQ-8012 increased to 5.8 and 8.3 g/L, respectively, compared with a yield of 3.7 g/L without enzymes added. Meanwhile, the addition of the BgaQ or BgaQ-8012 reduced the lactose content by 49.3% and 54.4% in the fermented yogurt and shortened the curd time. Therefore, this study provided a site-directed mutation strategy for improvement of the transgalactosylation activity of ß-galactosidase from Strep. thermophilus for GOS-enriched yogurt making.


Assuntos
Streptococcus thermophilus , Iogurte , Animais , Fermentação , Mutação , Streptococcus thermophilus/genética , Streptococcus thermophilus/metabolismo , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
3.
Zhonghua Fu Chan Ke Za Zhi ; 57(8): 594-600, 2022 Aug 25.
Artigo em Zh | MEDLINE | ID: mdl-36008286

RESUMO

Objective: To analyze the labor progression characteristics of primiparous term singleton pregnant women with adenomyosis. Methods: From April 2014 to May 2021, pregnant women underwent regular antenatal examination in Peking University Third Hospital were enrolled in this retrospective study, 109 primiparous term pregnant women with adenomyosis who underwent singleton, primipara, cephalic and vaginal delivery were referred as the adenomyosis group, while 109 pregnant women without adenomyosis primiparous term pregnant women at the same time were referred as the control group. The general clinical information, labor process intervention, pregnancy outcomes and labor course time of the two groups were analyzed. Results: (1) General clinical conditions: the pre-pregnancy uterine volume of the adenomyosis group was larger than that of the control group [(66.8±23.7) vs (41.4±13.1) cm3, P<0.05]. The proportion of assisted reproductive pregnancy and endometriosis in the adenomyosis group were higher than those in the control group [31.2% (34/109) vs 7.3% (8/109); 31.2% (34/109) vs 5.5% (6/109); all P<0.05]. There were no significant differences in maternal age, gestational age at delivery, pre-pregnancy body mass index, gestational weight gain, gravidity, incidence of pregnancy complications (gestational diabetes mellitus, pre-eclampsia and thyroid diseases) and premature rupture of membranes between the two groups (all P>0.05). (2) Labor process intervention and maternal and fetal outcomes: postpartum hemorrhage was higher in the adenomyosis group than the control group (median: 300 vs 260 ml, P=0.018). There were no significant differences in the proportion of labor onset, use of oxytocin, artificial rupture of membranes, perineal laceration Ⅲ and above, episiotomy, newborn weight and 1-minute Apgar score between the two groups (all P>0.05). (3) Time of labor process: there were no significant differences between the two groups in the time required for the first stage, third stage, total stage and cervical dilation 0-1, 1-2, 2-3, 3-4, 4-5, 5-6, 6-7 cm (all P>0.05). The time required for cervical dilation 7-8, 8-9, 9-10 cm and the second stage of labor in adenomyosis group (median: 20, 18, 15 and 12 minutes, respectively) were shorter than those of the control group (median: 23, 23, 23 and 26 minutes, respectively), and the differences were statistically significant (all P<0.05). (4) The effect of endometriosis on labor: there was no significant difference in the effect of endometriosis on labor in adenomyosis group (P>0.05). Conclusions: The labor process of primiparous term pregnant women with adenomyosis is significantly accelerated after the cervical dilatation for 7 cm, which should be closely observed. The third stage of labor course is managed aggressively with drugs to prevent postpartum hemorrhage.


Assuntos
Adenomiose , Endometriose , Trabalho de Parto , Hemorragia Pós-Parto , Adenomiose/epidemiologia , Endometriose/epidemiologia , Feminino , Humanos , Recém-Nascido , Gravidez , Gestantes , Estudos Retrospectivos
4.
J Chem Phys ; 152(5): 054906, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32035432

RESUMO

We propose a confinement model and study numerically the structural properties of particles with competing interactions in logarithmic traps (i.e., the confinement potential is a logarithmic function). A rich variety of cluster structures are observed as a function of trap steepness, trap size, and particle density. In addition to the consistent results with previous studies for a harmonic confinement, we observe some new stable structures, including a hybrid cluster structure consisting of clumps surrounded by a circular stripe, parallel stripes, or homogeneous voids surrounded by a ringlike arrangement of clumps, and a gear-like cluster with fringed outer rims evenly arranged along the circumference. Our work reveals that such self-organized structures arise due to the radial density reconfiguration in a finite confined system corresponding to the unconstrained systems, which is controlled by the interplay between the long-range repulsions and the attractions to the minimum of the confinement potential. Such results are likely relevant in understanding the structural properties of confined mermaid systems.

5.
Zhonghua Wai Ke Za Zhi ; 55(3): 214-219, 2017 Mar 01.
Artigo em Zh | MEDLINE | ID: mdl-28241724

RESUMO

Objective: To evaluate the clinical effect and imaging evaluation of cervical spine myelopathy treated with Centerpiece. Methods: A retrospective study of 60 patients underwent posterior cervical spine surgery because of cervical myelopathy in Spinal Department of Peking University People's Hospital from July 2011 to January 2013.According to the different fixation methods, all patients were divided into cervical posterior open-door Centerpiece fixation group (group A) and cervical posterior open-door silk suspension fixation group (group B). There were 40 patients in group A, including 25 males and 15 females, mean age (59.7±11.9) years old, average course of disease before surgery (53.6±61.5) months, average follow-up time (28.5±3.1) months after operation.There were 20 patients in group B, including 15 males and 5 females, mean age (58.3±9.6) years old, average course of disease before surgery (50.4±14.9) months, average follow-up time (28.3±1.9) months after operation.The operation time, intraoperative blood loss, postoperative drainage, preoperative and postoperative Japanese Orthopaedic Association(JOA) score, the neck disability index(NDI) score, visual analog scale (VAS) score, postoperative axial pain, C(5) nerve root palsy, postoperative "re-closing" and other related complications were observed.Imaging assessment projects include: before and after surgery of cervical curvature, range of motion(ROM), spinal anteroposterior diameter, spinal canal expansion rate, the whole spinal cord backward shift distance and area of the spinal canal and the opening angle. Results: There was no significant difference in general data between the two groups (P>0.05). Group A the average operation time was(117.7±23.4)min, the average amount of operative bleeding was (152.0±122.7) ml, and the postoperative drainage volume was (268.7±222.1) ml.The average operation time of group B was (141.7±23.9) min, the average amount of operative bleeding was (166.7±42.5) ml, and the postoperative drainage volume of group B was (255.3±47.0) ml.There was no significant difference between the two groups in the amount of operative bleeding and postoperative drainage volume (both P>0.05), the operation time between the two groups was statistically significant (P<0.05). At the end of the follow-up, the JOA score, NDI score, and VAS score were significantly improved (P<0.05) in both group A and group B and there was no significant difference between the two groups (P>0.05). C(5) nerve root paralysis was not occurred in both two groups after operation.There were 1 case of axial pain in the group A and 7 cases in the group B and there were significant differences between the two groups (P<0.05). The group A was not found "re-closing" during the follow-up and 12 patients of group B found to be "re-closing" phenomenon, there were statistically different between the two groups (P<0.05). Comparison of preoperative and postoperative, there were no significant differences in cervical curvature and ROM in both groups (P>0.05). Butthe spinal canal diameter and the vertebral canal area were statistically different after surgery (P<0.05). There was no statistical difference between the two groups of cervical curvature and ROM (P>0.05). There was no statistical difference between the two groups of spinal canal diameter, spinal canal area and spinal canal diameter enlargement rate(P>0.05). There was no statistical difference between the two groups of the whole spinal cord backward shift distance(P>0.05). There were significant differences between the two groups at the angle of the open door (P<0.05). Conclusion: Centerpiece cervical posterior titanium plate can achieve good clinical efficacy in the treatment of multi segmental spinal cervical spondylosis.


Assuntos
Placas Ósseas , Vértebras Cervicais , Fixação Interna de Fraturas , Espondilose/cirurgia , Adulto , Idoso , Feminino , Humanos , Laminectomia , Masculino , Pessoa de Meia-Idade , Pescoço , Duração da Cirurgia , Ortopedia , Complicações Pós-Operatórias , Período Pós-Operatório , Amplitude de Movimento Articular , Estudos Retrospectivos , Seda , Canal Medular , Doenças da Medula Espinal , Titânio , Resultado do Tratamento
6.
Clin Exp Immunol ; 171(3): 298-306, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23379436

RESUMO

In China, the majority of human immunodeficiency virus (HIV) infections are predominately subtype B. It is important to characterize the HIV-1 subtype B-specific and its T cell response within the Chinese population, with the aim of identifying protective correlates of immunity to control HIV-1 infections. In this study, we performed a comprehensive analysis looking into the magnitude/strength of T cell responses directed at the Gag protein of the HIV-1 subtype B, one of the most conserved HIV-1 proteins. The study group consisted of anti-retroviral native and chronic HIV-1 subtype B-infected individuals. We used enzyme-linked immunospot (ELISPOT) assay to quantify the total T cell responses to HIV-1 Gag at the single peptide level. Twenty-eight (38%) peptides were recognized in 24 (82·8%) individuals. The p24 was identified as the most frequently recognized subunit protein with the greatest T cell response in the test, which correlated positively with CD4(+) T cell count and inversely with viral load (VL). At the level of the human leucocyte antigen (HLA) supertypes, we detected the highest levels and a significant correlation with both the CD4(+) T cell count and the VL with Gag T cell responses in Bw4/Bw4. These findings demonstrate that (i) the HIV-1B Gag p24-specific immune responses play an important role in controlling viral replication and slowing clinical progression; and (ii) HLA-Bw4/Bw4 allele has stronger T cell responses, which is associated with slow clinical progression in Chinese HIV patients.


Assuntos
Progressão da Doença , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Antígenos HLA-B/imunologia , Linfócitos T/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Adulto , Sequência de Aminoácidos , ELISPOT , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/fisiopatologia , HIV-1/classificação , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular
7.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(3): 301-304, 2021 Jul 08.
Artigo em Zh | MEDLINE | ID: mdl-34286534

RESUMO

The invalid patents associated with schistosomiasis control were retrieved in the Chinese Patent Database of China National Intellectual Property Administration, the Baiten database and the incoPat database, and the overall trends, legal status, types, patent indexing and technical fields of all retrieved invalid patents were analyzed. As of December 30, 2020, there were totally 859 patents relating to schistosomiasis control, and 512 were invalid patents, with an invalid rate of 59.6%. The number of patent applications and invalid patents peaked in 2018, including 71 patent applications and 53 invalid patents. Among the 511 schistosomiasis control-related invalid patents with complete records, there were 425 invention patents, 81 utility model patents and 5 design patents, and 219 patents (42.9%) were invalid due to the termination of the patented right and 292 (57.1%) due to loss of the right for patent applications. The major technical points included medicines (chemicals), basic research, devices and detections, and the specialized fields were mainly concentrated in A61P33, G01N33, C12N15, C07K14 and A01N65. Our data demonstrate a high invalid rate of patents relating to schistosomiasis control in China. Secondary development and mining of the invalid patents in relation to schistosomiasis are recommended to make use of their values in the national schistosomiasis elimination program of China.


Assuntos
Esquistossomose , China/epidemiologia , Humanos , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle
8.
Phys Rev E ; 103(1-1): 012604, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33601588

RESUMO

We numerically investigate the nonequilibrium behaviors of classic particles with competing interactions confined in a two-dimensional logarithmic trap. We reveal a quench-induced surprising dynamics exhibiting rich dynamic patterns depending upon confinement strength and trap size, which is attributed to the time-dependent competition between interparticle repulsions and attractions under a circular confinement. Moreover, in the collectively diffusive motions of the particles, we find that the emergence of dynamic structure transformation coincides with a diffusive mode transition from superdiffusion to subdiffusion. These findings are likely useful in understanding the pattern selection and evolution in various chemical and biological systems in addition to modulated systems, and add a new route to tailoring the morphology of pattern-forming systems.

9.
J Exp Med ; 186(1): 7-16, 1997 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-9206992

RESUMO

Inoculation of macaques with live attenuated SIV strains has been shown to protect against subsequent challenge with wild-type SIV. The protective mechanism(s) remain obscure. To study the effect in more detail, we have investigated the role of virus-specific CTL responses in macaques infected with an attenuated SIV strain (pC8), which has a four-amino acid deletion in the nef gene, as compared with the wild-type SIVmac32H clone (pJ5). Cynomolgus macaques infected with pC8 were protected against subsequent challenge with pJ5 and did not develop any AIDS-like symptoms in the 12 months after infection. The pC8-induced protection was associated with high levels of virus-specific CTL responses to a variety of viral antigens. In contrast, pJ5-infected macaques had little, if any, detectable CTL response to the viral proteins after three months. The latter group of macaques also showed increased Fas expression and apoptotic cell death in both the CD4(+) and CD8(+) populations. In vitro, pJ5 but not pC8 leads to an increase in FasL expression on infected cells. Thus the expression of FasL may protect infected cells from CTL attack, killing viral-specific CTLs in the process, and providing a route for escaping the immune response, leading to the increased pathogenicity of pJ5. pC8, on the other hand does not induce FasL expression, allowing the development of a protective CTL response. Furthermore, interruption of the Fas-FasL interaction allows the regeneration of viral-specific CTL responses in pJ5-infected animals. This observation suggests an additional therapeutic approach to the treatment of AIDS.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Imunidade Celular , Glicoproteínas de Membrana/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia , Síndrome da Imunodeficiência Adquirida/imunologia , Animais , Proteína Ligante Fas , Citometria de Fluxo , Humanos , Células Jurkat
10.
J Exp Med ; 189(9): 1489-96, 1999 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-10224289

RESUMO

During HIV/SIV infection, there is widespread programmed cell death in infected and, perhaps more importantly, uninfected cells. Much of this apoptosis is mediated by Fas-Fas ligand (FasL) interactions. Previously we demonstrated in macaques that induction of FasL expression and apoptotic cell death of both CD4(+) and CD8(+) T cells by SIV is dependent on a functional nef gene. However, the molecular mechanism whereby HIV-1 induces the expression of FasL remained poorly understood. Here we report a direct association of HIV-1 Nef with the zeta chain of the T cell receptor (TCR) complex and the requirement of both proteins for HIV-mediated upregulation of FasL. Expression of FasL through Nef depended upon the integrity of the immunoreceptor tyrosine-based activation motifs (ITAMs) of the TCR zeta chain. Conformation for the importance of zeta for Nef-mediated signaling in T cells came from an independent finding. A single ITAM motif of zeta but not CD3epsilon was both required and sufficient to promote activation and binding of the Nef-associated kinase (NAK/p62). Our data imply that Nef can form a signaling complex with the TCR, which bypasses the requirement of antigen to initiate T cell activation and subsequently upregulation of FasL expression. Thus, our study may provide critical insights into the molecular mechanism whereby the HIV-1 accessory protein Nef contributes to the pathogenesis of HIV.


Assuntos
Produtos do Gene nef/metabolismo , HIV-1/metabolismo , Glicoproteínas de Membrana/biossíntese , Proteínas de Membrana/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Proteína Ligante Fas , HIV-1/fisiologia , Humanos , Células Jurkat , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Regulação para Cima , Produtos do Gene nef do Vírus da Imunodeficiência Humana , Quinases Ativadas por p21
11.
Clin Exp Immunol ; 159(1): 93-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19817769

RESUMO

Both invariant natural killer T (NK T) cells and CD4(+)CD25(+) T regulatory cells (T(regs)) regulate the immune system to maintain homeostasis. In a tumour setting, NK T cells activated by alpha-galactosylceramide (alpha-GalCer) execute anti-tumour activity by secreting cytokines. By contrast, T(regs) intrinsically suppress antigen-specific immune responses and are often found to be elevated in tumour patients. In this study, we have shown that T(regs) regulate NK T cell function negatively in vitro, suggesting a direct interaction between these cell types. In a murine mammary tumour model, we demonstrated that administration of either alpha-GalCer or anti-CD25 antibody alone markedly suppressed tumour formation and pulmonary metastasis, and resulted in an increase in the survival rate up to 44% (from a baseline of 0%). When treatments were combined, depletion of T(regs) boosted the anti-tumour effect of alpha-GalCer, and the survival rate jumped to 85%. Our results imply a potential application of combining T(reg) cell depletion with alpha-GalCer to stimulate NK T cells for cancer therapy.


Assuntos
Imunidade Celular/imunologia , Subunidade alfa de Receptor de Interleucina-2/imunologia , Depleção Linfocítica , Neoplasias Mamárias Experimentais/imunologia , Neoplasias Mamárias Experimentais/terapia , Células T Matadoras Naturais/imunologia , Linfócitos T Reguladores/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Células Dendríticas/imunologia , Modelos Animais de Doenças , Feminino , Galactosilceramidas/imunologia , Galactosilceramidas/uso terapêutico , Interferon gama/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Ativação Linfocitária/imunologia , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células T Matadoras Naturais/metabolismo , Taxa de Sobrevida , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/efeitos dos fármacos
12.
Trop Biomed ; 37(1): 50-57, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33612717

RESUMO

A 24-year-old man born in Guizhou province was diagnosed with obstructive jaundice and bile duct stones in 2013. Four living trematodes were found during laparotomy and cholecystectomy. Based on the morphology and molecular genetics analysis of internal transcribed spacer and pcox1 genes of the flatworm specimens, the trematodes from the patient were confirmed to be Fasciola hepatica. This report provided the clinical and molecular diagnosis information on human fascioliasis, which is an emerging sanitary problem still ignored in China. Human fascioliasis constantly occurs due to climatic changes and frequency of human travel. Therefore, it deserves more attention from physicians working in both developing and developed countries.


Assuntos
Fasciola hepatica/isolamento & purificação , Fasciolíase/diagnóstico , Animais , China , Colecistectomia , Fasciola hepatica/genética , Humanos , Icterícia Obstrutiva/cirurgia , Masculino , Filogenia , Adulto Jovem
13.
Curr Biol ; 7(9): 693-6, 1997 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9285725

RESUMO

A subset of the tumour necrosis factor (TNF) receptor family contain a conserved intracellular motif, the death domain. Engagement of these receptors by their respective ligands initiates a signalling cascade that rapidly leads to cell death by apoptosis. We have cloned a new member of this family, TRICK2, the TRAIL (TNF-related apoptosis-inducing ligand) receptor inducer of cell killing 2. TRICK2 is expressed in a number of cell types, and to particularly high levels in lymphocytes and spleen. Two isoforms of the TRICK2 mRNA are generated by alternative pre-mRNA splicing and differ by a 29 amino-acid extension to the extracellular domain. Overexpression of TRICK2 rapidly induced apoptosis in 293T cells; this induction was dependent upon the presence of the death domain of TRICK2. Using a soluble molecule containing the TRICK2 extracellular domain, we demonstrated that TRICK2, like DR4 [1], is a receptor for TRAIL/APO-2L [2,3] and could inhibit TRAIL-induced killing of lymphocyte lines, such as the Jurkat T-cell line. TRAIL is upregulated upon lymphocyte activation, as is the intensively studied ligand for Fas, FasL [4]. TRAIL and its receptors might therefore provide another system for the regulation of lymphocyte selection and proliferation, as well as providing an additional weapon in the armoury of cytotoxic lymphocytes.


Assuntos
Processamento Alternativo , Glicoproteínas de Membrana/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Sequência de Aminoácidos , Animais , Apoptose , Proteínas Reguladoras de Apoptose , Sítios de Ligação , Células COS , Clonagem Molecular , Dados de Sequência Molecular , Receptores do Ligante Indutor de Apoptose Relacionado a TNF , Receptores do Fator de Necrose Tumoral/genética , Ligante Indutor de Apoptose Relacionado a TNF
14.
Curr Biol ; 10(6): 333-6, 2000 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-10744980

RESUMO

In mammals, the classical B7 molecules expressed on antigen-presenting cells, B7-1 (CD80) and B7-2 (CD86), bind the structurally related glycoproteins CD28 and CTLA-4 (CD152), generating costimulatory signals that regulate the activation state of T cells. A recently identified human CD28-like protein, ICOS, also induces costimulatory signals in T cells when crosslinked with antibodies, but it is unclear whether ICOS is part of a B7-mediated regulatory pathway of previously unsuspected complexity, or whether it functions independently and in parallel. Here, we report that, rather than binding B7-1 or B7-2, ICOS binds a new B7-related molecule of previously unknown function that we call LICOS (for ligand of ICOS). At 37 degrees C, LICOS binds only to ICOS but, at lower, non-physiological temperatures, it also binds weakly to CD28 and CTLA-4. Sequence comparisons suggest that LICOS is the homologue of a molecule expressed by avian macrophages and of a murine protein whose expression is induced in non-lymphoid organs by tumour necrosis factor alpha (TNFalpha). Our results define the components of a distinct and novel costimulatory pathway and raise the possibility that LICOS, rather than B7-1 or B7-2, is the contemporary homologue of a primordial vertebrate costimulatory ligand.


Assuntos
Antígenos de Diferenciação de Linfócitos T/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Sequência de Aminoácidos , Animais , Antígenos CD , Antígenos de Diferenciação de Linfócitos T/genética , Sequência de Bases , Linhagem Celular Transformada , DNA Complementar , Humanos , Ligante Coestimulador de Linfócitos T Induzíveis , Proteína Coestimuladora de Linfócitos T Induzíveis , Ligantes , Glicoproteínas de Membrana/genética , Camundongos , Dados de Sequência Molecular , Proteínas/genética , Receptores de Antígenos de Linfócitos T/genética , Homologia de Sequência de Aminoácidos , Ressonância de Plasmônio de Superfície/métodos
15.
Curr Opin Immunol ; 12(3): 316-22, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10781406

RESUMO

An effective immune response requires the rapid and accurate mobilisation of millions of effector cells in an antigen driven fashion. These effector cells must be kept alive long enough to fulfil their function but the majority must then be eliminated, a process known as activation-induced cell death. Recent advances in the field of lymphocyte biology have shed light onto how this balance is maintained and onto the consequences for disease if the homeostatic mechanisms become disturbed.


Assuntos
Morte Celular , Receptores do Fator de Necrose Tumoral/metabolismo , Linfócitos T/imunologia , Antígenos CD/metabolismo , Modelos Imunológicos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF , Receptores Tipo I de Fatores de Necrose Tumoral , Transdução de Sinais , Receptor fas/metabolismo
17.
Sci Rep ; 7: 46424, 2017 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-28436423

RESUMO

Practical, efficient synthesis of metal oxide nanocrystals with good crystallinity and high specific surface area by a modified polymer-network gel method is demonstrated, taking ZnO nanocrystals as an example. A novel stepwise heat treatment yields significant improvement in crystal quality. Such nanophase materials can effectively degrade common organic dyes under solar radiation and can perform very well in photo-assisted detection of NO2 gas. Other typical metal oxide nanocrystals with good crystallinity and high specific surface area were also synthesized successfully under similar conditions. This work provides a general strategy for the synthesis of metal oxide nanocrystals, balancing the crystallinity and specific surface area.

18.
Adv Food Nutr Res ; 78: 137-51, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27452169

RESUMO

Marine actinobacteria are well recognized for their capabilities to produce valuable natural products, which have great potential for applications in medical, agricultural, and fine chemical industries. In addition to producing unique enzymes responsible for biosynthesis of natural products, many marine actinobacteria also produce hydrolytic enzymes which are able to degrade various biopolymers, such as cellulose, xylan, and chitin. These enzymes are important to produce biofuels and biochemicals of interest from renewable biomass. In this chapter, the recent reports of novel enzymes produced by marine actinobacteria are reviewed, and advanced technologies that can be applied to search for novel marine enzymes as well as for improved enzyme production by marine actinobacteria are summarized, which include ribosome engineering, genome mining, as well as synthetic biology studies.


Assuntos
Actinobacteria/enzimologia , Organismos Aquáticos/microbiologia , Enzimas/biossíntese , Organismos Aquáticos/enzimologia , Biopolímeros/metabolismo , Celulase/biossíntese , Celulase/metabolismo , Quitinases/biossíntese , Quitinases/metabolismo , Dimetilaliltranstransferase/biossíntese , Dimetilaliltranstransferase/metabolismo , Endo-1,4-beta-Xilanases/biossíntese , Endo-1,4-beta-Xilanases/metabolismo , Enzimas/genética , Halogenação , Hidrólise , Peptídeo Hidrolases/biossíntese , Peptídeo Hidrolases/metabolismo
19.
Mech Ageing Dev ; 51(3): 265-76, 1990 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-2106602

RESUMO

We studied T cell activation in the healthy aged (greater than 70 years) by examining lymphocyte proliferative responses to various mitogenic stimuli in accessory cell (AC)-dependent and AC-independent systems. Results show that despite a near normal response to the anti-CD3 monoclonal antibody (mAb) OKT3, peripheral blood mononuclear cells (PBM) from the elderly exhibit a profound reduction in phytohaemagglutinin (PHA)-responsiveness (approximately 30% of young adults). This deficit becomes even more severe at suboptimal doses of PHA. Adding exogenous interleukin-2 (IL-2) or pretreating the AC population with gamma interferon (IFN-gamma) returns the level of proliferation to that seen with young adults. Furthermore, replacing "old" AC with AC from young adults or with U937 (a monocytic cell line) in T cell/AC cell-mixing experiments restores PHA-responsiveness in 70% of cases. On the other hand, AC from the aged fully support PHA responses in T cells from young adults. In AC-depleted cultures, purified T cells from the aged respond normally to the co-mitogenic stimuli, PHA + PMA. Taken together, these results suggest that the age-associated diminution in PHA-responsiveness is due, at least in part, to specific deficiencies in T cell/AC communication.


Assuntos
Envelhecimento/imunologia , Células Apresentadoras de Antígenos/fisiologia , Linfócitos T/fisiologia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/imunologia , Comunicação Celular , Divisão Celular/fisiologia , Feminino , Humanos , Técnicas In Vitro , Interferon gama/imunologia , Interleucina-2/imunologia , Ativação Linfocitária , Masculino , Fito-Hemaglutininas/imunologia
20.
Biochimie ; 74(11): 975-9, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1477141

RESUMO

To determine whether or not endothelial cell survival was decreased after incubation with high glucose concentrations in culture media, we studied the influence of D-glucose or L-glucose (a non-metabolizable stereoisomer of D-glucose) on cell survival using the trypan-blue exclusion test. Simultaneously, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide) assay was used to measure both the mitochondrial respiratory chain activity and cell viability. Respiratory chain activity per cell increased when D-glucose concentrations rose but at the same time trypan-blue excluded cells were decreased. Comparison with data in the literature showed that the MTT assay was not reliable for studies involving endothelial cell survival when glucose reduction was affected on these cells. It seems important to check MTT assay reliability carefully when it is used for drugs affecting glucose metabolism, or with other cell types.


Assuntos
Transporte de Elétrons/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Glucose/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Colorimetria , Corantes , Meios de Cultura , Endotélio Vascular/citologia , Humanos , Sais de Tetrazólio , Tiazóis , Azul Tripano
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