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1.
Inorg Chem ; 62(20): 7681-7688, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37148562

RESUMO

Rare-earth (RE) chalcogenide borates are very rarely discovered in view of the difficulties in synthesis though they have demonstrated attractive physical performances. Here, the first mixed RE chalcogenide borates Eu5.4Sm3.6MgS2B20O41 (1) and Eu3Gd6MgS2B20O41 (2) are synthesized by combining RE, sulfur, and borate ions into one structure. They crystallize in the centrosymmetric hexagonal space group P63/m, and their 3D honeycomb-like {[B20O41]22-}∞ open frameworks are built by [B6O9(O0.5)6]6- and [B7O13(O0.5)3]8- polyanionic clusters and consolidated by Mg2+ ions; both of which are formed by BO4 tetrahedra and BO3 planar triangles. The coordination modes of RE ions are rare REO6S2 bicapped trigonal prisms and REO8S irregular polyhedra, and their band gaps are determined to be 2.25 and 2.22 eV, respectively. They exhibit antiferromagnetic interactions and distinct photocurrent responses. The corresponding theoretical calculations are also performed. The study of 1 and 2 perhaps stimulates interest in exploring new functional RE chalcogenide borates.

2.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(2): 194-201, 2021 Mar.
Artigo em Zh | MEDLINE | ID: mdl-33829691

RESUMO

OBJECTIVE: To construct eukaryotic and prokaryotic recombinant vectors containing Pepck- Gp63 and to achieve protein expression by selecting the dominant epitope genes of Pepck and Gp63 of Leishmania infantum. METHODS: The secondary structure and HLA epitopes of phosphoenolpyruvate carboxylase (PEPCK) were predicted by in silico analysis, and the dominant epitopes were picked out. According to the analysis results of glycoprotein of 63×10 3(GP63) epitopes identified by the same method in our laboratory, the dominant epitope genes of Pepck and Gp63 were used to construct pET32a- Pepck- Gp63 and pVAX1- Pepck- Gp63 by overlapping PCR and enzyme reaction. Then, for protein expression, the prokaryotic vectors were transfected into E.coil while the eukaryotic vectors were transfected into NIH3T3 cells by liposome transfection. RESULTS: There were multiple dominant epitopes in Pepckand there were Pepck-Gp63 sequences in the polyclonal site of expression vector. The expression of Pepck-Gp63 in E.coil appeared in inclusion form and led to 74 kDa band in SDS-PAGE. The immunofluorescence results of NIH3T3 cells transfected by pVAX1- Pepck-Gp63 were positive. CONCLUSION: The recombinant prokaryotic expression plasmids pET32a- Pepck-Gp63 and eukaryotic expression plasmids pVAX1- P epck -Gp63 were successfully constructed, and it was shown that the recombinant plasmids were able to express the corresponding target proteins in E. coli and NIH3T3 cells, respectively, providing a preliminary experimental basis for the subsequent study of immunization strategies.


Assuntos
Leishmania infantum , Animais , Epitopos/genética , Escherichia coli/genética , Eucariotos , Vetores Genéticos/genética , Leishmania infantum/genética , Camundongos , Células NIH 3T3 , Fosfoenolpiruvato Carboxilase , Plasmídeos
3.
BMC Plant Biol ; 20(1): 352, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32723291

RESUMO

BACKGROUND: Although the effect of cold stratification on seed dormancy release has been extensively studied for many species, knowledge of the role of stratifying temperature, soil moisture content and duration of stratification on seed dormancy release at the population level is limited. Here, we aimed to determine the response of seed dormancy release to these factors in six populations of Halenia elliptica. RESULTS: Seed dormancy release was more responsive to low than high temperatures, and no dormancy break occurred at 8 °C. Seed germination percentage increased first and then remained unchanged as stratifying soil moisture content increased from 0 to 24%. Seed dormancy release of populations from low altitude was more sensitive to increased stratifying temperature and decreased soil moisture content than those from high altitudes. CONCLUSIONS: Temperature and soil moisture changes resulting from global warming could affect seed dormancy release and consequently seedling establishment. Thus, incorporating data on seed dormancy release involving temperature, soil moisture content and stratification duration is beneficial for predicting plant species regeneration, migration and coexistence in a scenario of climate change.


Assuntos
Gentianaceae/fisiologia , Dormência de Plantas/fisiologia , Solo/química , Altitude , Temperatura Baixa , Germinação/fisiologia , Luz , Sementes/fisiologia , Fatores de Tempo
4.
Artigo em Inglês | MEDLINE | ID: mdl-30530601

RESUMO

Toxoplasma gondii is one of the most widespread obligatory parasitic protozoa and infects nearly all warm-blooded animals, leading to toxoplasmosis. The therapeutic drugs currently administered, like the combination of pyrimethamine and sulfadiazine, show high rates of toxic side effects, and drug resistance is encountered in some cases. Resveratrol is a natural plant extract with multiple functions, such as antibacterial, anticancer, and antiparasite activities. In this study, we evaluated the inhibitory effects of resveratrol on tachyzoites of the Toxoplasma gondii RH strain extracellularly and intracellularly. We demonstrate that resveratrol possesses direct antitoxoplasma activity by reducing the population of extracellularly grown tachyzoites, probably by disturbing the redox homeostasis of the parasites. Moreover, resveratrol was also able to release the burden of cellular stress, promote apoptosis, and maintain the autophagic status of macrophages, which turned out to be regulated by intracellular parasites, thereby functioning indirectly in eliminating T. gondii In conclusion, resveratrol has both direct and indirect antitoxoplasma effects against RH tachyzoites and may possess the potential to be further evaluated and employed for toxoplasmosis treatment.


Assuntos
Antiparasitários/farmacologia , Inibidores Enzimáticos/farmacologia , Resveratrol/farmacologia , Toxoplasma/efeitos dos fármacos , Toxoplasmose/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Interações Hospedeiro-Parasita/efeitos dos fármacos , Humanos , Macrófagos/imunologia , Camundongos , Extratos Vegetais/farmacologia , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
5.
BMC Vet Res ; 15(1): 446, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31818287

RESUMO

BACKGROUND: Leishmaniosis, a disease caused by pathogenic Leishmania parasites, remains an unresolved health problem in the New World and the Old World. It is well known that lizards can be infected by a subgenus of Leishmania parasites, i.e. Sauroleishmania, which is non-pathogenic to humans. However, evidence suggests that lizards may also harbor pathogenic Leishmania species including the undetermined Leishmania sp., discovered in our previous work. Leishmania DNA in lizard blood can be detected by using molecular methods, such as the polymerase chain reaction (PCR). RESULTS: Three hundred and sixteen lizards, representing 13 species of four genera, were captured for blood samples collection in Northwest China. Two reliable molecular markers (cytochrome b and heat shock protein 70 genes) were used for detection in the lizard blood samples, to confirm a widespread presence of pathogenic Leishmania parasites and the distribution pattern of Leishmania spp. in lizards from Northwest China. The PCR data indicated positive detection rate for Leishmania in all the tested lizards with an overall prevalence of 57.91% (183/316). Apart from lizard parasites like Leishmania tarentolae and Leishmania sp., several pathogenic Leishmania including L. turanica, L. tropica and L. donovani complex were identified by using phylogenetic analysis. Co-existence of different haplotypes was observed in most Leishmania DNA-positive lizards with an overall rate of 77.6% (142/183). Even mixed infections with different Leishmania species appeared to occur in the lizards with an overall rate of 37.7% (69/183). CONCLUSIONS: Lizards can harbor pathogenic Leishmania spp. Co-existence of different haplotypes or even species of Leishmania indicates mixed infections in natural lizard host. Lizards may contribute to the spread of Leishmania parasites. The pathogenic Leishmania species detected in lizards from Northwest China may be of great eco-epidemiological importance.


Assuntos
Leishmania/classificação , Leishmaniose/epidemiologia , Lagartos/parasitologia , Animais , China/epidemiologia , DNA de Protozoário/sangue , Haplótipos , Leishmania/genética , Lagartos/sangue , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
6.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 47(1): 1-6, 2016 Jan.
Artigo em Zh | MEDLINE | ID: mdl-27062772

RESUMO

OBJECTIVE: To generate and express fusion vector with mip/flaA advantages epitope genes of Legionella pneumophila by select mip and flaA advantages epitope genes for future research on Legionella pneumophila protein vaccine. METHODS: Following analysis of secondary structure and surface properties such as: physical and chemical properties, hydropathy, plasticity, antigen index and extracellular domain of Mip and FlaA proteins by bioinformatics methods, the region which active epitope may exist was selected as advantages epitope region. Then, the recombinant plasmid pET-mip, pET-flaA and pET-mip/flaA with advantages epitope genes were constructed by PCR amplification and T4 ligase connection, and induced the expression in E. coli. RESULTS: Many potential antigenic epitopes in Mip and FlaA were identified, and the selected advantages epitope regions were cloned and expressed successfully. Moreover, the mip/flaA two advantages associated epitope fusion proteins were also successfully expressed. CONCLUSION: DNA Star software and Expasy online analysis system can successfully predict antigenic epitopes for Legionella pneumophila Mip and FlaA. And prokaryotic expression vector pET-mip/flaA with advantages epitope genes has been successfully constructed and efficiently expressed.


Assuntos
Proteínas de Bactérias/genética , Epitopos/genética , Flagelina/genética , Vetores Genéticos , Legionella pneumophila/genética , Peptidilprolil Isomerase/genética , Antígenos de Bactérias/biossíntese , Antígenos de Bactérias/genética , Proteínas de Bactérias/biossíntese , Escherichia coli , Flagelina/biossíntese , Peptidilprolil Isomerase/biossíntese , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética
7.
Front Plant Sci ; 13: 820925, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35371120

RESUMO

As a versatile cruciferous species, Eruca sativa is widely cultivated, but in some areas, it has become an invasive weed. There are few studies on its seed dormancy and soil seed bank. This research examined seed dormancy, germination, and dynamics of the soil seed bank of E. sativa, with a view to provide support for its prevention and control. We tested the effects of temperature, light, storage, water, and salinity stress on seed germination and burial depth on seedling emergence of E. sativa. Dynamics of the soil seed bank were determined with a 24 month in situ seed-burial study. Seeds of E. sativa can germinate in a temperature range of 5-35°C; moreover, they exhibited non-deep physiological dormancy (NDPD) at maturity, which can be broken by dry storage or exposure to low temperature in winter. Germination of E. sativa seeds was sensitive to water and salinity stress, and most seeds did not germinate at -0.3 MPa. When buried in soil in the field, seeds exhibited an annual dormancy/non-dormancy cycle and formed at least a short-term persistent soil seed bank. Seeds buried deeper than 5 cm can hardly emerge. Seeds of E. sativa have a wide germination temperature range and exhibited dormancy cycling, which promotes the formation of a persistent soil seed bank and enables it to better adapt to the harsh low-temperature climate of the Qinghai-Tibet Plateau. No-tillage would be a good management strategy for this species.

8.
Updates Surg ; 74(3): 1087-1096, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33538992

RESUMO

To investigate comparative short-term outcomes of robotic-assisted surgery (RAS) versus video-assisted thoracoscopic surgery (VATS) for older non-small cell lung cancer (NSCLC) patients. Patients ≥ 65 years old with stage I-III NSCLC operated with RAS or VATS from 2016 to 2018 were consecutively included. Propensity score-matched (PSM) method was implemented to balance inter-group biases. Totally 376 participants (224 with VATS and 152 with RAS) were included. After PSM, a cohort (144 with VATS and 107 with RAS) was generated with balanced baseline characteristics. RAS was significantly superior over VATS in the majority of perioperative outcomes, such as operating time (120.8 vs. 165.1 min), conversion rate (0.0% vs. 19.4%), and length of stay (8.6 vs. 10.8 days). RAS versus VATS was significantly associated with comparable rates of postoperative complications (OR 0.642, 95% CI 0.311-1.327), except the rate of pneumonia (OR 0.161, 95% CI 0.048-0.544). RAS leads to analogous postoperative complications and seemingly accelerates the recovery time of older NSCLC patients compared with VATS.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Procedimentos Cirúrgicos Robóticos , Idoso , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Humanos , Tempo de Internação , Neoplasias Pulmonares/cirurgia , Pneumonectomia/métodos , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Cirurgia Torácica Vídeoassistida/efeitos adversos , Cirurgia Torácica Vídeoassistida/métodos
9.
Parasitol Res ; 109(1): 163-73, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21221640

RESUMO

Leishmaniasis is a geographically widespread disease caused by protozoan parasites belonging to the genus Leishmania and transmitted by certain species of sand fly. This disease still remains endemic in China, especially in the west and northwest frontier regions. A recent ITS1 phylogeny of Chinese Leishmania isolates has challenged some aspects for their traditional taxonomy and cladistic hypotheses of their phylogeny. However, disagreement with respect to relationships within Chinese Leishmania isolates highlights the need for additional data and analyses. Here, we test the phylogenetic relationships among Chinese isolates and their relatives by analyzing kinetoplast cytochrome oxidase II (COII) gene sequences, including 14 Chinese isolates and three isolates from other countries plus 17 sequences retrieved from GenBank. The COII gene might have experienced little substitution saturation, and its evolutionary process was likely to have been stationary, reversible, and homogeneous. Both neighbor-joining and Bayesian analyses reveal a moderately supported group comprising ten newly determined isolates, which is closely related to Leishmania tarentolae and Endotrypanum monterogeii. In combination with genetic distance analysis as well as Bayesian hypothesis testing, this further corroborates the occurrence of an undescribed species of Leishmania. Our results also suggest that (1) isolate MHOM/CN/93/GS7 and isolate IPHL/CN/77/XJ771 are Leishmania donovani; (2) isolate MHOM/CN/84/JS1 is Leishmania tropica; (3) the status referring to an isolate MRHO/CN/62/GS-GER20 from a great gerbil in Gansu, China, as Leishmania gerbilli, formerly based on multilocus enzyme electrophoresis, is recognized; and (4) E. monterogeii is nested within the genus Leishmania, resulting in a paraphyletic Leishmania. In addition, the results of this study enrich our understanding of the heterogeneity and relationships of Chinese Leishmania isolates.


Assuntos
DNA de Cinetoplasto/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Leishmania/classificação , Leishmania/isolamento & purificação , Leishmaniose/parasitologia , Animais , China , Análise por Conglomerados , DNA de Cinetoplasto/química , DNA de Protozoário/química , DNA de Protozoário/genética , Leishmania/enzimologia , Leishmania/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência
10.
J Thorac Dis ; 13(1): 220-231, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33569202

RESUMO

BACKGROUND: Some studies imply a strong correlation between smoking history and the efficacy of immune checkpoint inhibitors (ICIs) in patients with advanced non-small cell lung cancer (NSCLC). Hence, a systematic review and meta-analysis was conducted to comprehensively investigate this correlation. METHODS: Three online databases including PubMed, Embase and Cochrane Library were searched. Abstracts and presentations from European Society of Medical Oncology (ESMO) and American Society of Clinical Oncology (ASCO) were also reviewed. The deadline of search was Nov 9, 2019. Randomized clinical trials (RCT) of ICIs that reported hazard ratio (HR) for overall survival (OS) or progressive-free survival (PFS) by the smoking status of NSCLC patients were eligible for our study. We focused on publications issued in English. A random effects model was implemented in the synthesis, and a two-step interaction test was used to investigate the difference of ICIs efficacy among patients with different smoking histories. RESULTS: Twelve RCTs involving 6,497 NACLC patients [5,569 (85.72%) current/former smokers and 928 (114.28%) never smokers] were eligible for our systematic review and meta-analysis. The pooled HRs [95% confidential interval (CI)] of OS and PFS were 0.74 (0.67, 0.81) and 0.72 (0.59, 0.88) respectively for current/former smokers in the experimental group with ICIs versus those in the control group. The pooled HRs (95% CI) of OS and PFS were 0.81 (0.60, 1.08) and 0.92 (0.55, 1.54) respectively for never smokers in the experimental group with ICIs compared with those in the control group. The difference of ICIs efficacy in terms of OS between current/former and never smokers was insignificant [interaction HR (95% CI), 0.77 (0.69, 0.86), I2=25.4%, P_hetero=0.21]. CONCLUSIONS: The efficacy of ICIs in patients with smoking history is seemingly superior over patients without smoking history, but insignificantly. The difference can be explained by several factors such as insufficient sample size of non-smokers, and confounding factors. We suggest that smoking history cannot be recognized as a predictor of immune therapy in advanced NSCLC.

11.
Parasitol Res ; 107(5): 1049-65, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20617444

RESUMO

Leishmaniasis is a geographically widespread disease, caused by protozoan flagellates of the genus Leishmania. This disease still remains endemic in China, especially in the west and northwest frontier regions. To date, the phylogenetic relationships among Chinese Leishmania isolates are still unclear, and the possible taxonomic diversity remains to be established. In this study, the ITS1-5.8S fragments of ten isolates collected from different foci in China were determined. To infer the phylogenetic relationships among them, seven sequences of Chinese Leishmania isolates retrieved from GenBank were also included. Both parsimony and Bayesian analyses reveal an unexpected but strongly supported clade comprising eight newly determined isolates, which is sister to other members of subgenus Leishmania. In combination with genetic distance analysis, this provides evidence of the occurrence of an undescribed species of Leishmania. Our results also suggest that (1) the isolate IPHL/CN/77/XJ771 from Bachu County, Xinjiang Uygur Autonomous Region is not Leishmania infantum but Leishmania donovani; (2) the status referring to an isolate MRHO/CN/88/KXG-2 from a great gerbil in Karamay as Leishmania turanica, formerly based on multilocus enzyme electrophoresis, is recognized; (3) an earlier finding demonstrating the L. donovani identity of isolate MHOM/CN/80/801 from Kashi city is corroborated; (4) the three isolates from eastern Jiashi County, Xinjiang Uygur Autonomous Region, causing desert type of zoonotic visceral leishmaniasis (see Wang et al., Parasitol Int (in press), 2010), belong to L. donovani instead of L. infantum. In addition, the results of this study make an important contribution to understanding the heterogeneity and relationships of Chinese Leishmania isolates, further indicating that the isolates from China may have had a more complex evolutionary history than expected.


Assuntos
Leishmania/classificação , Leishmania/genética , Leishmaniose/parasitologia , Leishmaniose/veterinária , Animais , China , Análise por Conglomerados , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Genes de RNAr , Humanos , Leishmania/isolamento & purificação , Dados de Sequência Molecular , Filogenia , RNA de Protozoário/genética , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA
12.
Parasit Vectors ; 13(1): 94, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32085719

RESUMO

BACKGROUND: New therapeutic drugs are urgently needed against visceral leishmaniasis because current drugs, such as pentavalent antimonials and miltefosine, produce severe side effects and development of resistance. Whether cyclosporine A (CsA) and its derivatives can be used as therapeutic drugs for visceral leishmaniasis has been controversial for many years. METHODS: In this study, we evaluated the efficacy of CsA and its derivative, dihydrocyclosporin A (DHCsA-d), against promastigotes and intracellular amastigotes of Leishmania donovani. Sodium stibogluconate (SSG) was used as a positive control. RESULTS: Our results showed that DHCsA-d was able to inhibit the proliferation of L. donovani promastigotes (IC50: 21.24 µM and 12.14 µM at 24 h and 48 h, respectively) and intracellular amastigotes (IC50: 5.23 µM and 4.84 µM at 24 and 48 h, respectively) in vitro, but CsA treatment increased the number of amastigotes in host cells. Both DHCsA-d and CsA caused several alterations in the morphology and ultrastructure of L. donovani, especially in the mitochondria. However, DHCsA-d showed high cytotoxicity towards cells of the mouse macrophage cell line RAW264.7, with CC50 values of 7.98 µM (24 h) and 6.65 µM (48 h). Moreover, DHCsA-d could increase IL-12, TNF-α and IFN-γ production and decrease the levels of IL-10, IL-4, NO and H2O2 in infected macrophages. On the contrary, CsA decreased IL-12, TNF-α, and IFN-γ production and increased the levels of IL-10, IL-4, NO and H2O2 in infected macrophages. The expression of L. donovani cyclophilin A (LdCyPA) in promastigotes and intracellular amastigotes and the expression of cyclophilin A (CyPA) in RAW 264.7 cells were found to be significantly downregulated in the CsA-treated group compared to those in the untreated group. However, no significant changes in LdCyPA and CyPA levels were found after DHCsA-d or SSG treatment. CONCLUSIONS: Our findings initially resolved the dispute regarding the efficacy of CsA and DHCsA-d for visceral leishmaniasis treatment. CsA showed no significant inhibitory effect on intracellular amastigotes. DHCsA-d significantly inhibited promastigotes and intracellular amastigotes, but it was highly cytotoxic. Therefore, CsA and DHCsA-d are not recommended as antileishmanial drugs.


Assuntos
Antiprotozoários/farmacologia , Ciclosporina/farmacologia , Ciclosporinas/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Animais , Avaliação Pré-Clínica de Medicamentos , Humanos , Interferon gama/imunologia , Interleucina-10/imunologia , Interleucina-2/imunologia , Leishmania donovani/crescimento & desenvolvimento , Leishmania donovani/fisiologia , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/imunologia , Macrófagos/imunologia , Macrófagos/parasitologia , Camundongos , Células RAW 264.7
13.
Biomed Environ Sci ; 32(7): 520-530, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31331436

RESUMO

OBJECTIVE: To investigate the molecular characteristics and intracellular growth ability of Legionella pneumophila (L. pneumophila) strains from 1989 to 2016 in Sichuan Province, China. METHODS: Seventy-nine isolates of L. pneumophila were collected from environmental and clinical sources, including cooling towers, hot springs, bath water, fountains, and patients, and identified with 16S rRNA gene analysis and serum agglutination assay. The isolates were then typed by Sequence-Based Typing (SBT), and Genotyping of forty-two LP1 strains were analyzed by means of multiple-locus VNTR analysis with 8 loci (MLVA-8). All strains were further analyzed for two virulence genes: Legionella vir homologue (lvh) and repeats in structural toxin (rtxA). The intracellular growth ability of 33 selected isolates was determined by examining their interaction with J774 cells. RESULTS: All isolates were identified to L. pneumophila including 11 serogroups, among which the main serogroup were LP1, accounting for 54.43%. Thirty-three different sequence types (STs) from five main clonal groups and five singletons were identified, along with 8 different MLVA patterns. Both the lvh and rtxA loci were found in all 79 strains. Thirty isolates showed high intracellular growth ability in J774 cells. CONCLUSION: L. pneumophila is a potential threat to public health, and effective control and prevention strategies are urgently needed.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Legionella pneumophila/genética , RNA Ribossômico 16S/genética , China , Técnicas de Genotipagem , Humanos , Legionella pneumophila/crescimento & desenvolvimento , Legionella pneumophila/isolamento & purificação , Microbiologia da Água
15.
Acta Parasitol ; 62(1): 154-163, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28030353

RESUMO

Chinese Leishmania isolate MHOM/CN/90/SC10H2 (L. H2), which was obtained from the spinal cords of patients from the Sichuan province of China, is an uncharacterized, pathogenic species closely related to Leishmania tarentolae. The in vitro transformation rate of L. H2 promastigotes into amastigotes has not been studied. This study is the first to successfully define the in vitro life cycle of L. H2 by investigating the percent conversion of L.H2 promastigotes to amastigotes in vitro under 216 different culture conditions. The highest proportion of L. H2 amastigotes observed (94%) was significantly higher than that previously reported. After conversion, the axenic amastigotes remained viable as verified by the levels of stage-specific genes (Gp46, A2 and ß-tubulin) detected by RT-PCR. Meanwhile, morphological and protein characterizations of these axenic amastigotes were carried out in order to confirm the successful conversion. Specific antibodies were only able to detect 46 kDa, 52 kDa and 75 kDa proteins in samples isolated from axenic amastigotes. Afterward, these converted axenic amastigotes were transformed into the promastigote form by altering the culture condition. These converted axenic promastigotes still have the ability to infect macrophages, and their morphology changed back to the amastigote form following infection. These findings will assist further investigations into the biological characteristics of the host-parasite relationship and the process of pathogenesis.


Assuntos
Meios de Cultura/química , Leishmania/classificação , Leishmaniose/parasitologia , Estágios do Ciclo de Vida/fisiologia , China/epidemiologia , Humanos , Leishmaniose/epidemiologia , Fatores de Tempo
16.
Acta Trop ; 153: 101-10, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26482137

RESUMO

Leishmania spp. are able to survive and proliferate inside mammals' mononuclear phagocytes, causing Leishmaniasis. Previous studies have noted that the regulation of apoptosis in host cells by these parasites may contribute to their ability to evade the immune system. However, current results remain unclear about whether the parasites can promote or delay the apoptotic process in host cells, because the regulatory effect of Leishmania was assumed to be strain-, species- and even infection time-dependent. The aim of this study was to investigate whether the Sichuan isolates of Chinese Leishmania (SC10H2) can alter the process of intrinsic apoptosis induced by cycloheximide in different types of macrophage cell lines and to determine in which steps of the signaling pathway the parasites were involved. Human THP-1 and mouse RAW264.7 macrophages were infected by SC10H2 promastigotes followed by cycloheximide stimulation to assess the alteration of intrinsic apoptosis in these cells. The results indicated that SC10H2 infection of human THP-1 macrophages could promote the initiation of intrinsic apoptosis, but completely opposite results were found in mouse RAW264.7 macrophages. Nevertheless, the expression of Bcl-2 and the DNA fragmentation rates were not altered by SC10H2 infection in the cell lines used in the experiments. This study suggests that SC10H2 promastigote infection is able to promote and delay the transduction of early apoptotic signals induced by cycloheximide in THP-1 and RAW264.7 macrophages, revealing that the regulation of intrinsic apoptosis in host cells by SC10H2 in vitro occurs in a host cell-dependent manner. The data from this study might play a significant role in further understanding the relationship between Leishmania and different host cells.


Assuntos
Antiprotozoários/uso terapêutico , Apoptose/efeitos dos fármacos , Cicloeximida/uso terapêutico , Leishmaniose/tratamento farmacológico , Leishmaniose/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Animais , Linhagem Celular/efeitos dos fármacos , Humanos , Leishmania/efeitos dos fármacos , Camundongos
17.
Acta Trop ; 162: 83-94, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27338182

RESUMO

Leishmaniasis caused by Leishmania is still endemic in Northwest China. It has been thought that reptiles could be a reservoir for mammalian leishmaniasis. However, data are still scarce on natural infection of lizards with Leishmania spp. in China. The present study deals with detection, identification and phylogenetic inference of Leishmania parasites at species and intraspecies levels isolated from six desert lizard species from 10 geographical locations in Northwest China using amplification and sequencing of ITS-rDNA. In total, 83 haplotypes were found among 137 ITS1 sequences obtained from up to 64.6% of all captured lizards. Representative sequences of Leishmania available in GenBank were compiled for comparison with the obtained haplotypes. Tree-based species delimitation was achieved by using Bayesian phylogenitc analyses and maximum parsimony approach. Phylogenetic trees congruently supported that the haplotypes were found to belong to three Leishmania species including L. (sauroleishmania) sp., Leishmania tropica and Leishmania donovani complex. A network approach revealed paraphyletic populations of L. (sauroleishmania) sp. and L. tropica at intraspecies level regarding geographical origin and low host specificity. Chinese L. tropica from lizards showed significant heterogeneity as the obtained haplotypes were distributed in different clusters from other countries. Common ancestry was observed between some sequences of L. tropica from lizards and other sequence types from clinical samples from other countries. This may lend support to the potential reservoir role of lizards for human leishmaniasis. Our results appear to be the first molecular evidence for natural infection of lizards in Northwest China with reptilian Leishmania and mammalian Leishmania species. Desert lizards may be considered as putative reservoir hosts for Leishmania in China. Further studies on persistence of the Leishmania parasites in lizards and sandflies are recommended for the better understanding of their epidemiological involvement.


Assuntos
Haplótipos , Leishmania tropica/classificação , Leishmania tropica/genética , Leishmaniose/parasitologia , Lagartos/parasitologia , Filogenia , Análise de Sequência de DNA , Animais , Teorema de Bayes , China , DNA Ribossômico , Clima Desértico , Geografia , Humanos , Leishmania tropica/isolamento & purificação , Psychodidae/genética
18.
J Thorac Dis ; 7(11): 1939-50, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26716032

RESUMO

BACKGROUND: Numbers of studies have investigated the biological functions of decorin (DCN) in oncogenesis, tumor progression, angiogenesis and metastasis. Although many of them aim to highlight the prognostic value of stromal DCN expression in breast cancer, some controversial results still exist and a consensus has not been reached until now. Therefore, our meta-analysis aims to determine the prognostic significance of stromal DCN expression in breast cancer patients. METHODS: PubMed, EMBASE, the Web of Science and China National Knowledge Infrastructure (CNKI) databases were searched for full-text literatures met out inclusion criteria. We applied the hazard ratio (HR) with 95% confidence interval (CI) as the appropriate summarized statistics. Q-test and I(2) statistic were employed to estimate the level of heterogeneity across the included studies. Sensitivity analysis was conducted to further identify the possible origins of heterogeneity. The publication bias was detected by Begg's test and Egger's test. RESULTS: There were three English literatures (involving 6 studies) included into our meta-analysis. On the one hand, both the summarized outcomes based on univariate analysis (HR: 0.513; 95% CI: 0.406-0.648; P<0.001) and multivariate analysis (HR: 0.544; 95% CI: 0.388-0.763; P<0.001) indicated that stromal DCN expression could promise the high cancer-specific survival (CSS) of breast cancer patients. On the other hand, both the summarized outcomes based on univariate analysis (HR: 0.504; 95% CI: 0.389-0.651; P<0.001) and multivariate analysis (HR: 0.568; 95% CI: 0.400-0.806; P=0.002) also indicated that stromal DCN expression was positively associated with high disease-free survival (DFS) of breast cancer patients. No significant heterogeneity or publication bias was observed within this meta-analysis. CONCLUSIONS: The present evidences indicate that high stromal DCN expression can significantly predict the good prognosis in patients with breast cancer. The discoveries from our meta-analysis have better be confirmed in the updated review pooling more relevant investigations in the future.

19.
Parasit Vectors ; 6: 32, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23383990

RESUMO

BACKGROUND: Leishmania species belong to the family Trypanosomatidae and cause leishmaniasis, a geographically widespread disease that infects humans and other vertebrates. This disease remains endemic in China. Due to the large geographic area and complex ecological environment, the taxonomic position and phylogenetic relationship of Chinese Leishmania isolates remain uncertain. A recent internal transcribed spacer 1 and cytochrome oxidase II phylogeny of Chinese Leishmania isolates has challenged some aspects of their traditional taxonomy as well as cladistics hypotheses of their phylogeny. The current study was designed to provide further disease background and sequence analysis. METHODS: We systematically analyzed 50 cytochrome b (cyt b) gene sequences of 19 isolates (16 from China, 3 from other countries) sequenced after polymerase chain reaction (PCR) using a special primer for cyt b as well as 31 sequences downloaded from GenBank. After alignment, the data were analyzed using the maximum parsimony, Bayesian and netwok methods. RESULTS: Sequences of six haplotypes representing 10 Chinese isolates formed a monophyletic group and clustered with Leishmania tarentolae. The isolates GS1, GS7, XJ771 of this study from China clustered with other isolates of Leishmania donovani complex. The isolate JS1 was a sister to Leishmania tropica, which represented an L. tropica complex instead of clustering with L. donovani complex or with the other 10 Chinese isolates. The isolates KXG-2 and GS-GER20 formed a monophyletic group with Leishmania turanica from central Asia. In the different phylogenetic trees, all of the Chinese isolates occurred in at least four groups regardless of geographic distribution. CONCLUSIONS: The undescribed Leishmania species of China, which are clearly causative agents of canine leishmaniasis and human visceral leishmaniasis and are related to Sauroleishmania, may have evolved from a common ancestral parasite that came from the Americas and may have split off earlier than the other old world Leishmania. Our results also suggest the following: the isolates GS7, GS1 and XJ771 occur as part of the L. donovani complex; the JS1 isolate is L. tropica; and the isolate GS-GER20 identified as Leishmania gerbilli is close to KXG-2 which is L. turanica.


Assuntos
Citocromos b/genética , DNA de Cinetoplasto/genética , Leishmania/genética , Leishmania/isolamento & purificação , Filogeografia , China , Análise por Conglomerados , DNA de Cinetoplasto/química , DNA de Protozoário/química , DNA de Protozoário/genética , Genótipo , Leishmaniose/parasitologia , Leishmaniose/veterinária , Dados de Sequência Molecular , Análise de Sequência de DNA
20.
Clin Vaccine Immunol ; 19(4): 536-44, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22357648

RESUMO

In order to identify immunodominant antigens of Mycobacterium tuberculosis that may be used in the serodiagnosis of active tuberculosis (TB), we designed an M. tuberculosis fusion protein consisting of CFP-10 (10-kDa culture filtrate protein), ESAT-6 (6-kDa early secreted antigenic target), and the extracellular domain fragment of PPE68 (PPE68'). Then, the coding sequences of the three proteins were inserted into a prokaryotic expression vector, pET-32a(+). To enhance the immunological response, the proteins were linked together. The fusion proteins with a 6 × His tag were successfully overexpressed in Escherichia coli BL21 and purified. The purified proteins were applied for detection of the total IgG titer by using an enzyme-linked immunosorbent assay (ELISA) with human sera from well-characterized TB cases and the control cases, and results were compared to those with purified protein derivative tuberculin (PPD). The ELISA results showed that among 140 cases of confirmed active TB and 70 control cases, CFP-10-ESAT-6-PPE68' had a sensitivity of 73.3% and specificity of 94.3%, compared to a sensitivity of 66.7% and specificity of 74.3% for PPD and a sensitivity of 65% and specificity of 91.4% for CFP-10-ESAT-6. In addition, the fusion protein CFP-10-ESAT-6-PPE68' stimulated a higher level of antigen-specific gamma interferon (IFN-γ) release for active-TB patients than PPD and CFP-10-ESAT-6. After immunization of C57BL/6 mice, the findings indicated that the total IgG titers and the concentrations of IFN-γ in mice immunized by CFP-10-ESAT-6-PPE68' were high and induced strong, long-term humoral immunity compared to results with PPD and CFP-10-ESAT-6. Thus, our study indicates that the fusion protein CFP-10-ESAT-6-PPE68' may be useful as an immunodominant antigen for the serodiagnosis of active TB.


Assuntos
Antígenos de Bactérias , Proteínas de Bactérias , Mycobacterium tuberculosis/imunologia , Tuberculose/diagnóstico , Adulto , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Cromatografia de Afinidade , Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Expressão Gênica , Vetores Genéticos , Humanos , Imunoglobulina G/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mycobacterium tuberculosis/genética , Proteínas Recombinantes de Fusão/genética , Sensibilidade e Especificidade , Testes Sorológicos/métodos
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