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1.
Small ; 15(17): e1900288, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30920760

RESUMO

The catalytic performance of Pt-based catalysts for oxygen reduction reactions (ORR) can generally be enhanced by constructing high-index exposed facets (HIFs). However, the synthesis of Pt alloyed high-index skins on 1D non-Pt surfaces to further improve Pt utilization and stability remains a fundamental challenge for practical nanocrystals. In this work, Pd nanowires (NWs) are selected as a rational medium to facilitate the epitaxial growth of Pt and Ni. Based on the different nucleation and growth habits of Pt and Ni, a continuous PtNi alloy skin bounded with HIFs spiraled on a Pd core can be obtained. Here, the as-prepared helical Pd@PtNi NWs possess high HIF densities, low Pt contents, and optimized oxygen adsorption energies, demonstrating an enhanced ORR mass activity of 1.75 A mgPt -1 and a specific activity of 3.18 mA cm-2 , which are 10 times and 12 times higher than commercial Pt/C catalysts, respectively. In addition, the 1D nanostructure enables the catalyst to be highly stable after 30 000 potential sweeping cycles. This work successfully extends bulky high-indexed Pt alloys to core-shell nanostructures with the design of a new, highly efficient and stable Pt-based catalyst for fuel cells.

2.
Int J Mol Sci ; 20(20)2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31600954

RESUMO

Periodontal disease is the main reason for tooth loss in adults. Tissue engineering and regenerative medicine are advanced technologies used to manage soft and hard tissue defects caused by periodontal disease. We developed a transforming growth factor-ß3/chitosan sponge (TGF-ß3/CS) to repair periodontal soft and hard tissue defects. We investigated the proliferation and osteogenic differentiation behaviors of primary human periodontal ligament stem cells (hPDLSCs) to determine the bioactivity and potential application of TGF-ß3 in periodontal disease. We employed calcein-AM/propidium iodide (PI) double labeling or cell membranes (CM)-Dil labeling coupled with fluorescence microscopy to trace the survival and function of cells after implantation in vitro and in vivo. The mineralization of osteogenically differentiated hPDLSCs was confirmed by measuring alkaline phosphatase (ALP) activity and calcium content. The levels of COL I, ALP, TGF-ßRI, TGF-ßRII, and Pp38/t-p38 were assessed by western blotting to explore the mechanism of bone repair prompted by TGF-ß3. When hPDLSCs were implanted with various concentrations of TGF-ß3/CS (62.5-500 ng/mL), ALP activity was the highest in the TGF-ß3 (250 ng/mL) group after 7 d (p < 0.05 vs. control). The calcium content in each group was increased significantly after 21 and 28 d (p < 0.001 vs. control). The optimal result was achieved by the TGF-ß3 (500 ng/mL) group. These results showed that TGF-ß3/CS promotes osteogenic differentiation of hPDLSCs, which may involve the p38 mitogen-activated protein kinase (MAPK) signaling pathway. TGF-ß3/CS has the potential for application in the repair of incomplete alveolar bone defects.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Quitosana , Osteogênese/efeitos dos fármacos , Ligamento Periodontal/citologia , Células-Tronco/efeitos dos fármacos , Fator de Crescimento Transformador beta3/farmacologia , Biomarcadores , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quitosana/química , Humanos , Imuno-Histoquímica , Sistema de Sinalização das MAP Quinases , Células-Tronco/citologia , Fator de Crescimento Transformador beta3/química
3.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(2): 324-7, 2014 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-24749367

RESUMO

OBJECTIVE: To develop a new method for simultaneous determination of eight organochlorine pesticides (OCPs) in water samples using solidification floating organic drop liquid-phase microextraction (SFO-LPME) combined with gas chromatography-electronic capture detector (GC-ECD). METHODS: The experimental conditions of SFO-LPME were determined with n-Hexadecane as extractant, water samples adjusted to pH 6.0, inonic strength increased by adding 15.0 g/100 mL NaCI. The OCPs were extracted at 55 degrees C for 10 mm and determined with GC-ECD. RESULTS: A good linearity (correlation coefficients > or = 0.996) was obtained for eight target compounds from 5 ng/I. to 100 ng/L. The method detection limits ranged from 0.24 ng/L to 0.78 ng/L. Satisfactory results were achieved with samples of river water, piped water and farmland water, with an average recovery of 76.0%-106.0% and RSD of 3.24%-11.60%. CONCLUSION: The proposed method is rapid, simple and sensitive. It is suitable for hatch analyses of eight organic chlorine pesticides in water samples.


Assuntos
Água Doce/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Cromatografia Gasosa , Microextração em Fase Líquida
4.
Medicine (Baltimore) ; 103(25): e38474, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38905357

RESUMO

The link between celiac disease (CeD) and thyroid dysfunction has been investigated. However, it is uncertain if CeD is causally linked to thyroid dysfunction. A 2-sample Mendelian randomization study was conducted to ascertain the causal connection between CeD and thyroid dysfunction. Using data from the FinnGen Consortium, a 2-sample Mendelian randomization study was conducted to look at the connection between thyroid dysfunction and CeD. Another replication of the data from the UK Biobank was subsequently performed to confirm our findings. Furthermore, a sequence of sensitivity analyses was performed. The inverse variance weighting technique demonstrates that genetically determined CeD is substantially linked with hypothyroidism, thyrotoxicosis, Graves' disease, and free thyroxine. However, no significant associations were found between CeD and thyroid-stimulating hormone or thyroiditis. Moreover, we achieve the same results in duplicate datasets, which increases the reliability of our findings. This study suggests that CeD and thyroid dysfunction are linked, and it gives theoretical support and new ways of thinking about how to diagnose and treat both conditions.


Assuntos
Doença Celíaca , Análise da Randomização Mendeliana , Doenças da Glândula Tireoide , Humanos , Doença Celíaca/genética , Doença Celíaca/complicações , Doença Celíaca/epidemiologia , Doenças da Glândula Tireoide/genética , Doenças da Glândula Tireoide/epidemiologia , Hipotireoidismo/genética , Hipotireoidismo/epidemiologia , Tireotropina/sangue
5.
Bioengineering (Basel) ; 11(6)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38927838

RESUMO

Advanced glycation end product (AGE) accumulation due to diabetes causes vascular and neurological lesions, delaying healing. The use of stem cells could overcome these problems. Although many studies have shown the potential beneficial effects of stem cell therapies in the treatment of chronic and refractory skin ulcers, their delivery methods are still under investigation. Human periodontal ligament stem cells (hPDLSCs) can spontaneously differentiate into myofibroblasts in specific cultures; therefore, they have the potential to effectively treat diabetic wounds and may also have applications in the field of medical cosmetics. The myofibroblastic differentiation ability of hPDLSCs in the presence of AGEs was evaluated by the expression of α-SMA and COL1A1 using RT-qPCR and WB technology. Wound healing in diabetic mice, induced by streptozotocin (STZ) and assessed using H&E staining, Masson staining, and immunohistochemical (IHC) and immunofluorescence (IF) staining, was used to validate the effects of hPDLSCs. In the wound tissues, the expression of α-SMA, COL1A1, CD31, CD206, iNOS, and vimentin was detected. The findings indicated that in H-DMEM, the expression of COL1A1 exhibited a significant decrease, while α-SMA demonstrated an increase in P7 cells, ignoring the damage from AGEs (p < 0.05). In an STZ-induced diabetic C57BL/6J mice whole-skin defect model, the healing rate of the hPDLSCs treatment group was significantly higher than that in the models (on the 7th day, the rate was 65.247% vs. 48.938%, p < 0.05). hPDLSCs have been shown to spontaneously differentiate into myofibroblasts in H-DMEM and resist damage from AGEs in both in vivo and in vitro models, suggesting their potential in the field of cosmetic dermatology.

6.
Int J Nurs Sci ; 10(1): 46-52, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36860709

RESUMO

Objective: This study aimed to explore the perception on advanced directives (ADs) among older adults in Shanghai. Methods: Through purposive sampling, 15 older adults with rich life experiences who were willing to share perceptions and experiences of ADs participated in this study. Face-to-face semi-structured interviews were conducted to collect the qualitative data. Thematic content analysis was applied to analyze the data. Results: Five themes have been identified: low awareness but high acceptance of ADs; pursuing natural and peaceful sunset life; ambiguous attitude on medical autonomy; being irrational facing patients' dying and death issues; positive about implementing ADs in China. Conclusion: It is possible and feasible to implement ADs in older adults. Death education and compromised medical autonomy may be needed in the Chinese context as the foundation. The elder's understanding, willingness and worries about ADs should be fully revealed. Diverse approaches should be applied to introduce and interpret ADs to older adults continuously.

7.
J Funct Biomater ; 14(4)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37103283

RESUMO

Periodontal bone tissue defects and bone shortages are the most familiar and troublesome clinical problems in the oral cavity. Stem cell-derived extracellular vesicles (SC-EVs) have biological properties similar to their sources, and they could be a promising acellular therapy to assist with periodontal osteogenesis. In the course of alveolar bone remodeling, the RANKL/RANK/OPG signaling pathway is an important pathway involved in bone metabolism. This article summarizes the experimental studies of SC-EVs applied for the therapy of periodontal osteogenesis recently and explores the role of the RANKL/RANK/OPG pathway in their mechanism of action. Their unique patterns will open a new field of vision for people, and they will help to advance a possible future clinical treatment.

8.
Asian J Pharm Sci ; 17(3): 425-434, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35782329

RESUMO

Resorption and loss of alveolar bone leads to oral dysfunction and loss of natural or implant teeth. Biomimetic delivery of growth factors based on stem cell recruitment and osteogenic differentiation, as the key steps in natural alveolar bone regenerative process, has been an area of intense research in recent years. A mesoporous self-healing hydrogel (DFH) with basic fibroblast growth factor (bFGF) entrapment and transforming growth factor ß3 (TGFß3) - loaded chitosan microspheres (CMs) was developed. The formulation was optimized by multiple tests of self-healing, in-bottle inversion, SEM, rheological, swelling rate and in vitro degradation. In vitro tubule formation assays, cell migration assays, and osteogenic differentiation assays confirmed the ability of DFH to promote blood vessels, recruit stem cells, and promote osteogenic differentiation. The optimum DFH formula is 0.05 ml 4Arm-PEG-DF (20%) added to 1 ml CsGlu (2%) containing bFGF (80 ng) and TGFß3-microspheres (5 mg). The results of in vitro release studied by Elisa kit, indicated an 95% release of bFGF in 7 d and long-term sustained release of TGFß3. For alveolar defects rat models, the expression levels of CD29 and CD45, the bone volume fraction, trabecular number, and trabecular thickness of new bone monitored by Micro-CT in DFH treatment groups were significantly higher than others (*P < 0.05, vs Model). HE and Masson staining show the same results. In conclusion, DFH is a design of bionic alveolar remodelling microenvironment, that is in early time microvessels formed by bFGF provide nutritious to recruited endogenous stem cells, then TGFß3 slowly released speed up the process of new bones formation to common facilitate rat alveolar defect repair. The DFH with higher regenerative efficiency dovetails nicely with great demand due to the requirement of complicated biological processes.

9.
Front Pharmacol ; 12: 678322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33967817

RESUMO

Patients with a skull defect are at risk of developing cerebrospinal fluid leakage and ascending bacterial meningitis at >10% per year. However, treatment with stem cells has brought great hope to large-area cranial defects. Having found that transforming growth factor (TGF)-ß3 can promote the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), we designed a hybrid TGF-ß3/recombinant human-like collagen recombinant human collagen/chitosan (CS) freeze-dried sponge (TRFS) loading hPDLSCs (TRFS-h) to repair skull defects in rats. CFS with 2% CS was selected based on the swelling degree, water absorption, and moisture retention. The CS freeze-dried sponge (CFS) formed a porous three-dimensional structure, as observed by scanning electron microscopy. In addition, cytotoxicity experiments and calcein-AM/PI staining showed that TRFS had a good cellular compatibility and could be degraded completely at 90 days in the implantation site. Furthermore, bone healing was evaluated using micro-computed tomography in rat skull defect models. The bone volume and bone volume fraction were higher in TRFS loaded with hPDLSCs (TRFS-h) group than in the controls (p < 0.01, vs. CFS or TRFS alone). The immunohistochemical results indicated that the expression of Runx2, BMP-2, and collagen-1 (COL Ⅰ) in cells surrounding bone defects in the experimental group was higher than those in the other groups (p < 0.01, vs. CFS or TRFS alone). Taken together, hPDLSCs could proliferate and undergo osteogenic differentiation in TRFS (p < 0.05), and TRFS-h accelerated bone repair in calvarial defect rats. Our research revealed that hPDLSCs could function as seeded cells for skull injury, and their osteogenic differentiation could be accelerated by TGF-ß3. This represents an effective therapeutic strategy for restoring traumatic defects of the skull.

10.
Virol J ; 7: 94, 2010 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-20459851

RESUMO

Hand, foot and mouth disease (HFMD), a common contagious disease that usually affects children, is normally mild but can have life-threatening manifestations. It can be caused by enteroviruses, particularly Coxsackieviruses and human enterovirus 71 (HEV71) with highly variable clinical manifestations. In the spring of 2008, a large, unprecedented HFMD outbreak in Fuyang city of Anhui province in the central part of southeastern China resulted in a high aggregation of fatal cases. In this study, epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak. Of the 6,049 cases reported between 1 March and 9 May of 2008, 3023 (50%) were hospitalized, 353 (5.8%) were severe and 22 (0.36%) were fatal. HEV71 was confirmed as the etiological pathogen of the outbreak. Phylogenetic analyses of entire VP1 capsid protein sequence of 45 Fuyang HEV71 isolates showed that they belong to C4a cluster of the C4 subgenotype. In addition, genetic recombinations were found in the 3D region (RNA-dependent RNA polymerase, a major component of the viral replication complex of the genome) between the Fuyang HEV71 strain and Coxsackievirus A16 (CV-A16), resulting in a recombination virus. In conclusion, an emerging recombinant HEV71 was responsible for the HFMD outbreak in Fuyang City of China, 2008.


Assuntos
Surtos de Doenças , Enterovirus Humano A/genética , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/virologia , Recombinação Genética , Adolescente , Sequência de Bases , Criança , Pré-Escolar , China/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Enterovirus Humano A/classificação , Enterovirus Humano A/isolamento & purificação , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Filogenia , Proteínas Virais/genética
11.
J Periodontol ; 91(7): 975-985, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31573683

RESUMO

BACKGROUND: Periodontal ligament stem cells (PDLSCs) play an essential role in periodontal tissue repair. Basic fibroblast growth factor (bFGF) has been used in the clinical treatment of periodontal disease. However, studies have shown that bFGF inhibits the osteogenic differentiation of PDLSCs, which is not conducive to alveolar bone repair. Sulfonated chitosan oligosaccharide (SCOS), a heparan-like compound, can maintain the conformation of bFGF and promote its proliferation activity. This study investigated the effects of bFGF in combination with SCOS on the osteogenic differentiation of hPDLSCs. METHODS: hPDLSCs were isolated from healthy human periodontal ligament and identified by flow cytometry and immunofluorescence. The affinity between SCOS and bFGF was analyzed by surface plasmon resonance. Changes in osteogenic differentiation by combination of bFGF with SCOS were analyzed by alkaline phosphatase activity assay, Sirius Red staining, and Alizarin Red staining. Expression of genes and proteins was investigated by western blotting and reverse transcription-quantitative PCR. RESULTS: Extracted hPDLSCs were mesenchymal stem cells with pluripotent differentiation potential. SCOS exhibited an affinity for bFGF. bFGF (20 ng/mL) promoted the proliferation of hPDLSCs, but inhibited their osteogenic differentiation. SCOS alleviated the inhibitory effect of bFGF on the osteogenic differentiation of hPDLSCs. CONCLUSIONS: SCOS can reduce the inhibitory effect of bFGF on the osteogenic differentiation of hPDLSCs. This study provides evidence for the clinical use of bFGF to repair periodontal tissue.


Assuntos
Quitosana , Ligamento Periodontal , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Quitosana/farmacologia , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Oligossacarídeos , Osteogênese , Células-Tronco
12.
Artigo em Inglês | MEDLINE | ID: mdl-19010721

RESUMO

2-(4-Fluorobenzylideneamino) propanoic acid was synthesized through the reaction of 4-fluorobenzaldehyde and alpha-alanine in refluxing EtOH. Its structure was verified by (1)H NMR, FTIR and Raman spectroscopy. The ground-state geometries were optimized at B3LYP/6-31G*, B3LYP/6-31+G** and B3LYP/6-31G** level without symmetry constrains. The vibrational wavenumbers of 4-FA were calculated at same level. The scaled theoretical spectra using B3LYP methods are in a good agreement with the experimental ones. The title compound was tested for anticancer activity of the Hela cell line (using an MTT viability assay) with an IC(50) 166.6 microg/mL.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Modelos Químicos , Propionatos/química , Propionatos/farmacologia , Teoria Quântica , Vibração , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Modelos Moleculares , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Termodinâmica
13.
Asian J Pharm Sci ; 14(5): 511-520, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32104478

RESUMO

Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor (aFGF) promotes the growth and survival of neurons and is a possible treatment for peripheral nerve injury. Yet, the actual therapeutic utility of aFGF is limited by its short half-life and instability in vivo. In the present study, we prepared sulfated chitooligosaccharides (SCOS), which have heparin-like properties, to improve the bioactivity of aFGF. We investigated the protective effects of SCOS with or without aFGF on RSC96 cells exposed to Na2S2O4 hypoxia/reoxygenation injury. Cell viability was measured by MTT assay and cytotoxicity induced by Na2S2O4 was assessed by lactate dehydrogenase (LDH) release into the culture medium. Pretreatment with aFGF and SCOS dramatically decreased LDH release after injury compared to pretreatment with aFGF or SCOS alone. We subsequently prepared an aFGF/SCOS thermo-sensitive hydrogel with poloxamer and examined its effects in vivo. Paw withdrawal thresholds and thermal withdrawal latencies were measured in rats with sciatic nerve injury. Local injection of the aFGF/SCOS hydrogels (aFGF: 40, 80 µg/kg) increased the efficiency of sciatic nerve repair compared to aFGF (80 µg/kg) hydrogel alone. Especially aFGF/SCOS thermo-sensitive hydrogel decreased paw withdrawal thresholds from 117.75 ± 8.38 (g, 4 d) to 65.74 ± 3.39 (g, 10 d), but aFGF alone group were 140.58 ± 27.54 (g, 4 d) to 89.12 ± 5.60 (g, 10 d) (aFGF dose was 80 µg/kg, P < 0.05, n = 8). The thermal withdrawal latencies decreased from 11.61 ± 2.26 (s, 4 d) to 2.37 ±0.67 (s, 10 d). However, aFGF alone group were from 17.69 ± 1.47 (s, 4 d) to 4.65 ± 1.73 (s, 10 d) (P < 0.05, n = 8). Furthermore, the aFGF/SCOS hydrogels also exhibited good biocompatibility in mice. In summary, SCOS improved the protective effects of aFGF in RSC96 cells injured with Na2S2O4 and increased the efficiency of nerve repair and recovery of function in rats with sciatic nerve injury. These findings pave an avenue for the development of novel prophylactic and therapeutic strategies for peripheral nerve injury.

14.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 39(4): 579-82, 2008 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-18798498

RESUMO

OBJECTIVE: To find the enamel matrix proteins on the impact of enamel mineralization through experiments. METHODS: A combination of protein and beneficial carboxyl groups was grafted on the surface of enamel defects of rats through UV radiation then put into the enamel matrix proteins of calcium phosphate agar acetate solution systems, through scanning enamel surface with the electron microscopy to observe the morphological changes of enamel then analyse the regulation that enamel matrix proteins have done to the white hydroxyapatite crystals on the composition and morphology. RESULTS: In the enamel matrix protein added gel system, we can see the growth of hydroxyapatite crystals, and crystal showed a good degree of crystallinity and contained a small amount of CO3(2-) substituted hydroxyapatite crystals. CONCLUSION: The temperature at 37 degrees C water bath, after adding the enamel matrix proteins to gel system, the new hydroxyapatite crystals were numerous which proved that enamel matrix proteins played an important role in nucleation and growth of hydroxyapatite crystal, so it could be indicated that enamel matrix proteins could induce the enamel remineralization.


Assuntos
Proteínas do Esmalte Dentário/farmacologia , Esmalte Dentário/efeitos dos fármacos , Durapatita/análise , Remineralização Dentária/métodos , Animais , Cristalização , Esmalte Dentário/metabolismo , Esmalte Dentário/ultraestrutura , Proteínas do Esmalte Dentário/metabolismo , Durapatita/química , Eletroforese em Gel de Poliacrilamida , Feminino , Masculino , Microscopia Eletrônica de Varredura , Ratos , Ratos Sprague-Dawley
15.
Vet Parasitol ; 143(1): 14-20, 2007 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-16982153

RESUMO

Giardia, a most primitive eukaryote, infects several species including human and it is a major agent of waterborne outbreak of diarrhea. It has been difficult to employ standard genetic methods in the study of Giardia, but the RNA virus-based transfection system has been developed and used for the genetic manipulation. KRR1 protein is responsible for ribosome biosynthesis in Giardia. In this study, cDNA encoding hammerhead ribozyme flanked with various lengths of antisense Krr1 RNA were cloned into a viral vector pGCV634/GFP/GCV2174 derived from the genome of Giardia canis virus (GCV). RNA transcripts of the plasmids showed high cleavage activities on Krr1 mRNA in vitro. They were electroporated into GCV-infected G. canis trophozoites and Krr1 mRNA level was decreased by 72% with the ribozyme KRzS and 86% with the ribozyme KRzL, while the control ribozyme TRzS showed no effect on the level of Krr1 mRNA. The two hammerhead ribozyme transfected cells grew slowly, their internal structures got blurred and the cells were deformed. These results indicated that GCV could be useful tool for gene manipulation of G. canis.


Assuntos
Regulação Viral da Expressão Gênica , Giardia , Giardiavirus/genética , Proteínas de Ligação a RNA/metabolismo , Animais , Giardia/genética , Giardia/virologia , Plasmídeos , RNA Antissenso , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Ribossomos/metabolismo , Transfecção
16.
Artigo em Chinês | MEDLINE | ID: mdl-18038796

RESUMO

OBJECTIVE: To detect the cleavage activity of Giardia canis virus (GCV) transfer vector-mediated hammerhead ribozyme for KRR1 in vitro transcript. METHODS: Giardia, a most primitive eukaryote, has KRR1 protein responsible for ribosome biosynthesis. cDNA encoding hammerhead ribozyme flanked with various lengths of antisense RNA was cloned into a viral vector pGCV634/GFP/GCV2174 derived from the genome of GCV, KRzS flanked with 21 nt KRR1 antisense RNA on each arm, or KRzL flanked with 288 nt and 507 nt KRR1 antisense RNA. At the same time, two control groups were established: PKR without the inserted ribozyme, and TRzL flanked with 324 nt and 380 nt triosephosphate isomerase (Tim) antisense RNA. The cleavage activity of GCV transfer vector-mediated hammerhead ribozyme for KRR1 in vitro transcript was then analyzed by absolute real-time quantitative RT-PCR. RESULTS: The in vitro cleavage activities on KRR1 mRNA of the two ribozyme KRzS or KRzL were 74.0% and 81.1% respectively by the absolute real-time quantitative RT-PCR. The two control groups, PKR or TRzL, showed no effect on KRR1 mRNA in vitro. CONCLUSION: The GCV transfer vector-mediated hammerhead ribozyme shows a high cleavage activity for KRR1 in vitro transcript, which demonstrates the feasibility of using a viral vector to express a ribozyme targeted at a specific mRNA in Giardia to reduce the expression of a specific gene.


Assuntos
Giardiavirus/genética , RNA Catalítico/genética , Transcrição Gênica , Proteínas Virais/genética , Animais , Vetores Genéticos/genética , Giardia/genética , Giardia/virologia , RNA Antissenso/genética , RNA Catalítico/metabolismo , RNA de Protozoário/genética , RNA de Protozoário/metabolismo , Transfecção
17.
Artigo em Chinês | MEDLINE | ID: mdl-17639697

RESUMO

OBJECTIVE: To construct Giardia canis virus (GCV) transfection vector. METHODS: According to transcriptional start site, replication origin and packaging site of GCV genome (DQ238861), a system was developed for the expression of a foreign gene in this organism by flanking the green fluorescent protein (GFP) gene with the fragments of GCV positive-strand RNA. The transcript of the construct was synthesized in vitro with T7 RNA polymerase and used to transfect GCV-infected trophozoites by electroporation. RESULTS: The recombinant plasmid pGCV634/GFP/GCV2174 was constructed. The expression of green fluorescent protein mediated by GCV transfection vector in Giardia canis peaked at 1 d after electroporation (A490=1.8), and slowly decreased until 14 d post-transfection. CONCLUSION: The engineered GCV vector can be successfully used to introduce and efficiently express a heterologous gene in the eukaryotic microorganism.


Assuntos
Giardia/genética , Giardiavirus/genética , Proteínas de Fluorescência Verde/genética , Proteínas Recombinantes de Fusão/genética , Animais , Células Cultivadas , Eletroporação , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos/genética , Giardia/citologia , Giardia/virologia , Giardiavirus/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Microscopia de Fluorescência , Proteínas Recombinantes de Fusão/metabolismo , Transfecção/métodos
18.
Respir Care ; 62(5): 602-614, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28246307

RESUMO

BACKGROUND: The primary goals of this study were to evaluate early changes in pulmonary function and retrobulbar hemodynamics and to examine the correlation between these parameters in patients with type 2 diabetes during the preclinical stages of diabetic retinopathy. METHODS: For the single-time point measurements, 63 subjects with type 2 diabetes without diabetic retinopathy (diabetes group) and 32 healthy subjects (control group) were selected to evaluate any early changes in pulmonary function and retrobulbar hemodynamics and to examine the correlation between these parameters. In the longitudinal follow-up study, 32 subjects who were newly diagnosed with type 2 diabetes were divided into 2 groups according to their resistivity index (≤0.7 and >0.7). Early changes in pulmonary function and retrobulbar hemodynamics were studied in these groups and compared with the previous values. RESULTS: For the single-time point measurements, the fasting plasma glucose, 2-h postprandial blood glucose, glycosylated hemoglobin A1c, total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels as well as the pulmonary function parameters were significantly higher in the diabetes group than in the control group. The pulmonary function parameters were negatively and significantly correlated with glycosylated hemoglobin A1c and the duration of diabetes. The retrobulbar hemodynamics were positively correlated with glycosylated hemoglobin A1c and diabetes duration; in contrast, the correlation between retrobulbar hemodynamics and glycosylated hemoglobin A1c. In the longitudinal follow-up study, the pulmonary function of the 2 groups categorized by their resistivity index levels indicated that subjects with resistivity index levels ≤0.7 showed significantly better pulmonary function, and the pulmonary function of this group showed improvement and a significantly smaller decrease. The incidence of diabetic retinopathy in the group with resistivity index levels ≤0.7 (9 of 22, 40.9%) was significantly lower than that in the group with resistivity index levels >0.7. CONCLUSIONS: Pulmonary function and retrobulbar hemodynamics changed during the preclinical stages of diabetic retinopathy. Regulating glycemia may improve retrobulbar hemodynamics in the retrobulbar arteries (ie, central retinal artery, posterior ciliary artery, and arteria ophthalmica). By detecting the retrobulbar resistivity index and the levels of glycosylated hemoglobin A1c, we could predict future changes in pulmonary function during the preclinical stages of diabetic retinopathy as well as the degree of retinopathy. (ClinicalTrials.gov registration NCT02774733.).


Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Retinopatia Diabética/fisiopatologia , Pulmão/fisiopatologia , Doenças Retinianas/fisiopatologia , Adulto , Idoso , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/sangue , Retinopatia Diabética/etiologia , Feminino , Seguimentos , Hemoglobinas Glicadas/análise , Hemodinâmica , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Artéria Oftálmica/fisiopatologia , Testes de Função Respiratória , Artéria Retiniana/fisiopatologia , Doenças Retinianas/etiologia
19.
Fitoterapia ; 77(1): 28-34, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16242269

RESUMO

Bioassay-guided fractionation of the n-BuOH extract of the starfish Culcita novaeguineae resulted in the isolation of one new sulfated steroidal glycoside (asterosaponin) (1), along with three known asterosaponins, thornasteroside A (2), marthasteroside A(1) (3) and regularoside A (4), as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Their structures were elucidated by extensive spectral studies and chemical evidences. All the saponins showed moderate cytotoxicity against cancer cell lines K-562 and BEL-7402.


Assuntos
Saponinas/química , Saponinas/isolamento & purificação , Estrelas-do-Mar/química , Animais , Ascomicetos/efeitos dos fármacos , Bioensaio , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Saponinas/toxicidade , Esteróis/química , Esteróis/isolamento & purificação , Esteróis/toxicidade , Testes de Toxicidade/métodos
20.
Artigo em Chinês | MEDLINE | ID: mdl-17094593

RESUMO

OBJECTIVE: To cultivate a Giardia canis isolate with G. canis virus (GCV). METHODS: Five-day-old Meriones unguiculatus was infected with the cysts of G. canis isolated from dogs in Changchun and purified by sucrose density gradient centrifugation-G1 acid funnel filtration method. Trophozoites were isolated aseptically from the duodenum of the infected rodent after 8 days, then transferred to modified TYI-S-33 medium and cultivated at 37 degrees C. The trophozoites were centrifuged with 3,000 x g, 15 min after liquid nitrogen freeze-thawing three times and the supernatant stained negatively by phosphotungstic acid was observed with transmission electron microscope. RESULTS: G. canis trophozoites which adapted gradually to the environment and grew a cellular monolayer after 14 days were examined by freezing and thawing experiment, purity quotient, stability, biology characteristics and microbial contamination detection. The results demonstrated that a stable G. canis trophozoite cell isolate was established. G. canis virus with icosahedron spherical shape and 36 nm in diameter was observed by electron microscope. CONCLUSION: In vitro cultivation of G. canis trophozoites with GCV is established.


Assuntos
Giardia/virologia , Giardíase , Giardiavirus/isolamento & purificação , Animais , Cães , Gerbillinae , Giardíase/transmissão , Trofozoítos , Cultura de Vírus/métodos
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