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1.
ACS Appl Mater Interfaces ; 13(38): 45315-45324, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34520665

RESUMO

Active targeted therapy for bowel cancer using untethered microrobots has attracted extensive attention. However, traditional microrobots face challenges, such as issues of mobility, biocompatibility, drug loading, sustained-release capabilities, and targeting accuracy. Here, we propose an untethered triple-configurational magnetic robot (TCMR) that is composed of three geometrically nested parts: actuation and guarding, anchoring and seeding, and drug release part. A targeting magnetic driving system actuates the TCMR along the predetermined trajectory to the target position. The pH-sensitive actuation and guarding part formed by electrodeposition is degraded in the intestinal environment and separates from the two other parts. A majority of magnetic nanoparticles encapsulated in this part are retrieved. The anchoring and seeding part anchors the lesion area and seeds the drug release part in the gaps of intestinal villi by hydrolysis. Ultimately, the drug release part containing the therapeutic completes the sustained release to prolong the duration of the therapeutic agent. Cytotoxicity and therapeutic tests reveal that TCMRs are biocompatible and suitable for targeted therapy and have good therapeutic performance. The newly designed TCMR will provide new ideas for targeted therapy, thus expanding the application scope of robotics technology in the biomedical field.

2.
Sci Robot ; 6(52)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-34043546

RESUMO

Swimming biohybrid microsized robots (e.g., bacteria- or sperm-driven microrobots) with self-propelling and navigating capabilities have become an exciting field of research, thanks to their controllable locomotion in hard-to-reach areas of the body for noninvasive drug delivery and treatment. However, current cell-based microrobots are susceptible to immune attack and clearance upon entering the body. Here, we report a neutrophil-based microrobot ("neutrobot") that can actively deliver cargo to malignant glioma in vivo. The neutrobots are constructed through the phagocytosis of Escherichia coli membrane-enveloped, drug-loaded magnetic nanogels by natural neutrophils, where the E. coli membrane camouflaging enhances the efficiency of phagocytosis and also prevents drug leakage inside the neutrophils. With controllable intravascular movement upon exposure to a rotating magnetic field, the neutrobots could autonomously aggregate in the brain and subsequently cross the blood-brain barrier through the positive chemotactic motion of neutrobots along the gradient of inflammatory factors. The use of such dual-responsive neutrobots for targeted drug delivery substantially inhibits the proliferation of tumor cells compared with traditional drug injection. Inheriting the biological characteristics and functions of natural neutrophils that current artificial microrobots cannot match, the neutrobots developed in this study provide a promising pathway to precision biomedicine in the future.

3.
J Mater Chem B ; 9(4): 1030-1039, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33398321

RESUMO

Small intestine-targeted drug delivery by oral administration has aroused the growing interest of researchers. In this work, the child-parent microrobot (CPM) as a vehicle protects the child microrobots (CMs) under a gastric acid environment and releases them in the small intestinal environment. The intelligent hydrogel-based CPMs with sphere, mushroom, red blood cell, and teardrop shapes are fabricated by an extrusion-dripping method. The CPMs package uniform CMs, which are fabricated by designed microfluidic (MF) devices. The fabrication mechanism and tunability of CMs and CPMs with different sizes and shapes are analyzed, modeled, and simulated. The shape of CPM can affect its drug release efficiency and kinetic characteristics. A vision-feedback magnetic driving system (VMDS) actuates and navigates CPM along the predefined path to the destination and continuously releases drug in the simulated intestinal fluid (SIF, a low Reynolds number (Re) regime) using a new motion control method with the tracking-learning-detection (TLD) algorithm. The newly designed CPM combines the advantages of powerful propulsion, good biocompatibility, and remarkable drug loading and release capacity at the intestinal level, which is expected to be competent for oral administration of small intestine-targeted therapy in the future.


Assuntos
Doxorrubicina/química , Sistemas de Liberação de Medicamentos , Hidrogéis/química , Nanopartículas de Magnetita/química , Robótica , Células Cultivadas , Criança , Humanos , Dispositivos Lab-On-A-Chip , Fenômenos Magnéticos , Tamanho da Partícula , Robótica/instrumentação , Propriedades de Superfície
4.
Proc Natl Acad Sci U S A ; 117(45): 27916-27926, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33106419

RESUMO

Magnetically actuated miniature soft robots are capable of programmable deformations for multimodal locomotion and manipulation functions, potentially enabling direct access to currently unreachable or difficult-to-access regions inside the human body for minimally invasive medical operations. However, magnetic miniature soft robots are so far mostly based on elastomers, where their limited deformability prevents them from navigating inside clustered and very constrained environments, such as squeezing through narrow crevices much smaller than the robot size. Moreover, their functionalities are currently restricted by their predesigned shapes, which is challenging to be reconfigured in situ in enclosed spaces. Here, we report a method to actuate and control ferrofluid droplets as shape-programmable magnetic miniature soft robots, which can navigate in two dimensions through narrow channels much smaller than their sizes thanks to their liquid properties. By controlling the external magnetic fields spatiotemporally, these droplet robots can also be reconfigured to exhibit multiple functionalities, including on-demand splitting and merging for delivering liquid cargos and morphing into different shapes for efficient and versatile manipulation of delicate objects. In addition, a single-droplet robot can be controlled to split into multiple subdroplets and complete cooperative tasks, such as working as a programmable fluidic-mixing device for addressable and sequential mixing of different liquids. Due to their extreme deformability, in situ reconfigurability and cooperative behavior, the proposed ferrofluid droplet robots could open up a wide range of unprecedented functionalities for lab/organ-on-a-chip, fluidics, bioengineering, and medical device applications.

5.
Small ; 16(23): e1906701, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32378351

RESUMO

A magnetic urchin-like microswimmer based on sunflower pollen grain (SPG) that can pierce the cancer cell membrane and actively deliver therapeutic drugs is reported. These drug loaded microperforators are fabricated on a large scale by sequentially treating the natural SPGs with acidolysis, sputtering, and vacuum loading. The microswimmers exhibit precise autonomous navigation and obstacle avoidance in complex environments via association with artificial intelligence. Assemblies of microswimmers can further enhance individual motion performance and adaptability to complicated environments. Additionally, the experimental results demonstrate that microswimmers with nanospikes can accomplish single-cell perforation for direct delivery under an external rotating magnetic field. Drugs encapsulated in the inner cavity of the microperforators can be accurately delivered to a specific site via remote control. These dual-action microswimmers demonstrate good biocompatibility, high intelligence, precision in single-cell targeting, and sufficient drug loading, presenting a promising avenue for many varieties of biomedical applications.


Assuntos
Inteligência Artificial , Neoplasias , Humanos , Campos Magnéticos , Magnetismo
6.
Sci Total Environ ; 715: 136911, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32007887

RESUMO

The sources of supra-permafrost water and its hydrological effects were studied, based on the presence of stable isotopes in 562 samples collected in different ablation periods from the source regions of the Yangtze River. The δ18O (δD and d-excess) values for the initial ablation, ablation, and end ablation periods were -10.18‰ (-71.39‰ and 10.08‰), -12.14‰ (-85.58‰ and 11.51‰) and -11.50‰ (-78.75‰ and 13.23‰), respectively. The order of the slopes for the supra-permafrost water evaporation lines from the different ablation periods was initial ablation (IA) > ablation (A) > end ablation (EA). An anti-altitude effect is documented here, for a specific altitude range, in what is believed to be the first record of such an occurrence. Outside of that range, clear altitude effects were apparent. We have been able to show that supra-permafrost water was mainly recharged by atmospheric precipitation, ground ice, and glacier and snow meltwater, in the initial ablation and end ablation periods, and contributions from glacier and snow meltwater were mainly concentrated in higher altitude regions. In contrast, in the ablation period, supra-permafrost water was mainly recharged by atmospheric precipitation and ground ice. The contributions of precipitation to supra-permafrost water were 78.79%, 85.47%, and 82.99% in the initial ablation, ablation, and end ablation periods, respectively. The contributions of ground ice to the supra-permafrost water were 14.05%, 14.53%, and 11.94%, respectively, while contributions of glacier and snow meltwater were 7.15% and 5.07% in the initial and end ablation period. For the initial ablation, ablation, and end ablation periods, contributions from atmospheric precipitation to the supra-permafrost water were 85.47%, 86.86%, and 86.84%, while contributions from ground ice were 14.53%, 13.14% and 13.16%, respectively.

7.
Chemosphere ; 248: 126082, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32032884

RESUMO

The study investigates transformation mechanism of ions on different waters in Alpine region through analyzed the hydrochemical characteristics of the major ions of precipitation, glacier and snow meltwater, supra-permafrost water and river water in permafrost regions in the Tibetan Plateau under climate warming. The results showed that, The relation between recharge and discharge was the major ways for ionic transformation of each water body. Precipitation and glacier and snow meltwater are the main input sources for ionic transformation, and river water is the final output source. Different water bodies had different ionic concentrations and different hydrochemical types. However, different water bodies in different months (from June to September) also had different hydrochemical types. The water - rock interaction, reactions for ions, dilution effect and other effect for ions played an important role in the process of ion transformation. The increasing of temperature would lead to the accelerated melting of glaciers, permafrost and snow in the alpine regions, so the amount of supra-permafrost water and glacier and snow meltwater will increase, which leads to the increase of runoff. Meanwhile, the increase of temperature makes evaporation stronger. The strong of evaporation will accelerate the transformation of liquid water to gaseous water. Moreover, ion translation and water conversion are synchronous. Accordingly, ions are also accelerating transformation in the process of accelerated transformation of water body. Climate change is not only the main driving force for multiphase water transformation, but also the main driving force for the ion transformation of various water bodies.


Assuntos
Ânions/análise , Cátions/análise , Mudança Climática , Camada de Gelo/química , Rios/química , Neve/química , Altitude , China , Congelamento , Modelos Teóricos , Estações do Ano
8.
Nanoscale ; 11(39): 18382-18392, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31573587

RESUMO

Recent progress of untethered mobile micromotors has shown immense potential for targeted drug delivery in vivo. However, designing a wireless micromotor with high maneuverability and biocompatibility and achieving controlled drug release with high efficiency at a specific position remains a great challenge. Herein, we present a pine pollen-based micromotor (PPBM) and demonstrate its potential application as a cargo carrier for targeted drug delivery. These multifunctional biohybrid micromotors were massively and inexpensively fabricated by the encapsulation of magnetic particles (Fe3O4) and medicine into the two hollow air sacs of pine pollen, via vacuum loading. PPBMs successfully inherit the intrinsic functionalities of pine pollen: structural uniformity, morphological stability, biocompatibility, autofluorescence (AF) and physicochemical robustness. Under an external magnetic field, the loaded Fe3O4 enables individual and swarm PPBMs to propel precisely in complex biological fluids. Capitalizing on the magnetic nanoparticle aggregation phenomenon under a powerful magnetic field, controlled release of the therapeutic cargo is achieved using a fluid field generated by the rotating magnetic agglomerate. The biohybrid micromotors reported here turn natural pine pollen into active and controllable cargo carriers for biomedical applications.


Assuntos
Doxorrubicina , Campos Magnéticos , Nanopartículas de Magnetita/química , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Células HeLa , Humanos
9.
Sci Robot ; 4(28)2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-33137748

RESUMO

Swimming microrobots that are energized by external magnetic fields exhibit a variety of intriguing collective behaviors, ranging from dynamic self-organization to coherent motion; however, achieving multiple, desired collective modes within one colloidal system to emulate high environmental adaptability and enhanced tasking capabilities of natural swarms is challenging. Here, we present a strategy that uses alternating magnetic fields to program hematite colloidal particles into liquid, chain, vortex, and ribbon-like microrobotic swarms and enables fast and reversible transformations between them. The chain is characterized by passing through confined narrow channels, and the herring school-like ribbon procession is capable of large-area synchronized manipulation, whereas the colony-like vortex can aggregate at a high density toward coordinated handling of heavy loads. Using the developed discrete particle simulation methods, we investigated generation mechanisms of these four swarms, as well as the "tank-treading" motion of the chain and vortex merging. In addition, the swarms can be programmed to steer in any direction with excellent maneuverability, and the vortex's chirality can be rapidly switched with high pattern stability. This reconfigurable microrobot swarm can provide versatile collective modes to address environmental variations or multitasking requirements; it has potential to investigate fundamentals in living systems and to serve as a functional bio-microrobot system for biomedicine.

10.
Scanning ; 2018: 3979576, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29692874

RESUMO

An efficient and adaptive boundary tracking method is developed to confine area of interest for high-efficiency local scanning. By using a boundary point determination criterion, the scanning tip is steered with a sinusoidal waveform while estimating azimuth angle and radius ratio of each boundary point to accurately track the boundary of targets. A local scan region and path are subsequently planned based on the prior knowledge of boundary tracking to reduce the scan time. Boundary tracking and local scanning methods have great potential not only for fast dimension measurement but also for sample surface topography and physical characterization, with only scanning region of interest. The performance of the proposed methods was verified by using the alternate current mode scanning ion-conductance microscopy, tapping, and PeakForce modulation atomic force microscopy. Experimental results of single/multitarget boundary tracking and local scanning of target structures with complex boundaries demonstrate the flexibility and validity of the proposed method.

11.
ACS Nano ; 12(3): 2539-2545, 2018 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-29443501

RESUMO

We report a magnetically actuated peanut-shaped hematite colloid motor that can not only move in a rolling or wobbling mode in fluids but also perform single cell manipulation and patterning in a noncontact way. The peanut motor in a rolling mode can reach a maximal velocity of 10.6 µm s-1 under a rotating magnetic field of 130 Hz and 6.3 mT and achieve a more precisely controllable motion in predefined tracks. While in a wobbling mode, the motor reaches a maximal velocity of 14.5 µm s-1 under a conical rotating magnetic field of 80 Hz and 6.3 mT and can climb over steep slopes to adapt the motor for more complex environments. The fluid flow simulation results reveal that the difference between two movement modes mostly comes from the distribution discrepancy of the flow fields near the motors. Through the integration of the rolling and wobbling movement, these peanut motors can autonomously transport and release cells to a predefined site and thus form complex cell patterns without a physical contact. Such magnetically actuated peanut colloid motors afford a biofriendly technique for manipulation and patterning of cells, cell measurements, and intracellular communication investigations.


Assuntos
Coloides/química , Compostos Férricos/química , Imãs/química , Micromanipulação/instrumentação , Análise Serial de Tecidos/instrumentação , Animais , Desenho de Equipamento , Campos Magnéticos , Camundongos , Movimento (Física) , Células NIH 3T3
12.
Nat Commun ; 9(1): 304, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29335511

RESUMO

In the original version of this Article, the text labels on the bottom-right graph in Fig. 1c were inadvertently displaced during the production process. This has now been corrected in both the PDF and HTML versions of the Article.

13.
Nat Commun ; 8(1): 1944, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29208894

RESUMO

Stiffness matching between the probe and deformed portion of the sample in piezo-drive peak force modulation atomic force microscopy (AFM) limits the modulus measurement range of single probes. Here we develop a magnetic drive peak force modulation AFM to broaden the dynamic range of the probe with direct cantilever excitation. This approach not only successfully drives the softest commercial probe (6 pN nm-1) for mapping extremely soft samples in liquid but also provides an indentation force of hundreds of nanonewtons for stiff samples with a soft probe. Features of direct measurements of the indentation force and depth can unify the elastic modulus range up to four orders of magnitude, from 1 kPa to 10 MPa (in liquid) and 1 MPa to 20 GPa (in air or liquid) using a single probe. This approach can be particularly useful for analysing heterogeneous samples with large elastic modulus variations in multi-environments.

14.
J Glob Antimicrob Resist ; 1(3): 117-122, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27873621

RESUMO

Infections caused by multidrug-resistant and extensively drug-resistant Gram-negative bacilli are increasingly challenging to manage in hospitals and long term-care facilities worldwide. As the therapeutic options are limited, the International Society of Chemotherapy in collaboration with the Asia-Pacific Society of Clinical Microbiology and Immunology organised a consensus conference as part of the 13th Asia-Pacific Congress of Clinical Microbiology and Infection. A panel of international experts from Europe, the Americas and Asia were convened to discuss the issues of therapeutic options for the management of these difficult-to-treat pathogens.

15.
Zhong Yao Cai ; 35(5): 689-93, 2012 May.
Artigo em Chinês | MEDLINE | ID: mdl-23213727

RESUMO

OBJECTIVE: To investigate the resources and distribution of Arbuscular Mycorrhizal Fungi (AMF) in rhizosphere of Coptis deltoidea. METHODS: The colonization situation of AMF of Coptis deltoidea were detected by acid fuchsin staining and then calculated the colonization rate. AMF fungal spores were obtained by Wet-screening method and then classified and identified by their morphological characteristics and histochemical staining method. RESULTS: Coptis deltoidea and AMF could engender the mycorrhiza. Colonization rates were different in different producing areas and ranged from 23. 3% to 34.4%. Thirty species of AMF belonging in 6 genera were found, including 17 species of the Acaulospora, 7 of the Glomus, 2 of the Gigaspora, 1 of the Entrophospora, 1 of the Paraglomus and 2 of the Archaeospora were isolated from rhizosphere of Coptis deltoidea. Acaulospora and Glomus were the dominant genera and the AMF species of genuine producing regions in Hongya county was the most diversiform among the six areas. CONCLUSION: Coptis deltoidea is a kind of nutrition type of mycorrhiza plant. The rich diversity of AMF of Coptis deltoidea in producing areas make the AMF is a biological resource of significant application prospects in enlarging yield and non-pollution production.


Assuntos
Biodiversidade , Coptis/microbiologia , Micorrizas/classificação , Raízes de Plantas/microbiologia , Microbiologia do Solo , Contagem de Colônia Microbiana/métodos , Conservação dos Recursos Naturais , Coptis/crescimento & desenvolvimento , Ecossistema , Fungos/classificação , Fungos/isolamento & purificação , Fungos/fisiologia , Micorrizas/isolamento & purificação , Micorrizas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Esporos Fúngicos/classificação , Esporos Fúngicos/isolamento & purificação , Esporos Fúngicos/fisiologia
16.
Zhong Xi Yi Jie He Xue Bao ; 10(2): 176-85, 2012 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-22313885

RESUMO

BACKGROUND: Hepatitis B-related acute-on-chronic liver failure (ACLF) is a severe clinical syndrome characterized by jaundice, coagulopathy, ascites and hepatic encephalopathy and with a high mortality rate of 65% to 93%. It involves significant ethical issues when a randomized, double-blinded, placebo-controlled clinical study is conducted to such a serious disease. Therefore, a prospective cohort study design was utilized to explore a new treatment modality of applying integrated traditional Chinese and Western medicine. OBJECTIVE: To evaluate the efficacy, safety and recent survival rates of high-dose herbs with the function of clearing heat and resolving stasis, named Qingre Huayu, in patients with hepatitis B-related ACLF with heat toxin stagnation syndrome. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: A matched, prospective cohort study was conducted. Participants who met the inclusion criteria were recruited from the Department of Infectious Diseases, Affiliated Hospital of Chengdu University of Traditional Chinese Medicine. Patients were assigned to either an integrated medicine group or a Western medicine group according to their own preference and received either a regime of classic Western medical treatment (control group) or a regime of classic Western medical treatment plus Qingre Huayu herbs (treatment group). The regimes were conducted for 12 weeks. MAIN OUTCOME MEASURES: Survival rates of non-liver transplantation patients were evaluated after 12-week treatment. The levels of total bilirubin (TBiL), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and prothrombin activity (PTA) were detected at baseline and weeks 4, 8 and 12. Scores of traditional Chinese medicine (TCM) syndrome and complications were evaluated at baseline and study completion. Adverse events were recorded. RESULTS: All patients were followed up to the deadline for this study. There were 21 cases (31.8%) who died in the treatment group (n=66) and 19 cases (59.4%) in the control group (n=32). Significant difference (X(2)=6.775, P<0.01) was found in comparing the survival and death rates between the two groups by X(2) test. At 12 weeks, mean survival time of the two groups was 69.9 and 47.2 d respectively; cumulative survival rate of patients in the treatment group was higher than that of patients in the control group (P<0.01). Levels of TBiL, ALT, AST, ALB and PTA at weeks 4, 8 and 12 in the treatment group were superior to those in the control group with statistical significance (P<0.01 or P<0.05). In comparison of the TCM syndrome scores at week 12, the average score of the TCM syndrome of the treatment group (n=45) was 7.52±2.41, lower than 18.34±4.36 of the control group (n=13), and the difference was significant (t=8.784, P<0.01). Complication incidences after 12 weeks of treatment were statistically different between the treatment group (n=45) and the control group (n=13) by X(2) test (P<0.05 or P<0.01). Incidence rates of ascites, infection and hepatic encephalopathy accounted for 22.22%(10/45) and 69.23% (9/13), 8.89% (4/45) and 53.85% (7/13), and 11.11% (5/45) and 46.15% (6/13) in the two groups respectively. The incidence rates of adverse events in the treatment group and the control group were 0.00% and 12.50% respectively and the difference was statistically significant (X(2)=5.705, P<0.05). No drug-related adverse events were found in blood, urine and stool routine tests, renal function test and electrocardiography. CONCLUSION: High doses of Qingre Huayu herbs can significantly improve liver function and coagulation function, reduce complications, and reduce mortality in patients with hepatitis B-related ACLF.


Assuntos
Medicamentos de Ervas Chinesas/administração & dosagem , Hepatite B/complicações , Falência Hepática/tratamento farmacológico , Fitoterapia/métodos , Adulto , Medicamentos de Ervas Chinesas/uso terapêutico , Doença Hepática Terminal/dietoterapia , Doença Hepática Terminal/etiologia , Feminino , Humanos , Falência Hepática/etiologia , Falência Hepática/mortalidade , Falência Hepática Aguda/tratamento farmacológico , Falência Hepática Aguda/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida , Resultado do Tratamento
17.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 42(5): 661-5, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-22007494

RESUMO

OBJECTIVE: To investigate the correlation between the phenotype and expression level of femB of Staphylococcus aureus (MRSA), to discuss the mechanism of different phenotypes in methicillin-resistant Staphylococcus aureus. METHODS: The minimal inhibitory concentrations (MICs) of oxacillin against 71 clinical isolates of Staphylococcus aureus were determined by agar dilution method according to NCCLS. The production of beta-lactamase was identified by Cefinase paper strip method. The isolation rate of beta-lactamase-producing strains was counted and the correlation between the resistance phenotype and isolation rate of beta-lactamase was analysed by statistics. Real time fluorescent quantitative PCR was used to quantify the mRNA expression of femB of non-beta-lactamase-producing strains. RESULTS: The resistance rate of 71 Staphylococcus aureus to oxacillin was 66.20% (47/71), the isolation rate of beta-lactamase-producing MSSA strains was 58.3%,and that of strains of high- and low-level resistance to oxacillin were 63.15% and 55.56%. The standard curve was performed by series dilution of the heterogeneous resistant strain BB270, and the amount of femB-specific mRNA in strain BB270 was set to be 1. The calculated femB amounts in MSSA strains were from 0.4830-3.3636, while the amounts were from 0.4204-3.3636 in low-level MRSA strains, and 0.0718-16.0000 in high-level MRSA strains. There were no difference in the level of femB among MSSA, high-level MRSA and low-level MRSA. CONCLUSION: The expression level of femB may not be related to the resistance of non-beta-lactamase-producting Staphylococcus aureus to methicillin.


Assuntos
Proteínas de Bactérias/metabolismo , Resistência Microbiana a Medicamentos/genética , Staphylococcus aureus Resistente à Meticilina/genética , Oxacilina/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Sequência de Bases , Staphylococcus aureus Resistente à Meticilina/metabolismo , Dados de Sequência Molecular , Fenótipo , beta-Lactamases/metabolismo
18.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 28(1): 199-202, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21485213

RESUMO

Similar to multicellular animals, single-cell organisms, such as bacteria show the phenomenon of programmed cell death (PCD). The PCD not only can play an important role in various physiological procedures, but also can eliminate bacteria with irreversible injuries. The PCD of single cell in a colony is for the benefits of other bacteria in the same colony to achieve the development and reproduction of the whole colony. Disturbing or destroying such PCD may provide a new way for antibiotic drug research and development.


Assuntos
Autofagia/fisiologia , Bactérias/citologia , Staphylococcus aureus/citologia , Staphylococcus aureus/fisiologia , Streptococcus pneumoniae/citologia , Streptococcus pneumoniae/fisiologia
19.
Zhongguo Zhong Yao Za Zhi ; 35(14): 1855-8, 2010 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-20939284

RESUMO

OBJECTIVE: To observe the impact of Rhizoma Coptidis (drug-chemical extract parts-components) on 3T3-L1 pre-adipocytes differentiation and adipocytes insulin resistance, and reveal the pharmacodyamic material basis of Rhizoma Coptidis on insulin resistance. METHOD: 3T3-L1 pre-adipocytes were well cultured, and then induced to differentiate into fat cells by using dexamethasone, 3-isobutyl-1-methyl-xanthine and insulin together, and establish the insulin resistance model. Based on the experience of traditional medicine use, the adipocytes differentiation and the glucose consumption in the cell culture medium were observed independently. RESULT: Aqueous extract, different chemical extract fraction and different alkaloid extract from the herb showed inhibitory effects on 3T3-L1 pre-adipocytes differentiation, especially the compound coptisine significantly inhibited the differentiation in the concentration of 16.5 micromol x L(-1), but non-alkaloid extract from the herb promoted cell differentiation significantly in the concentration of 6.0 micromol x L(-1). Each treatment group, especially jatrorrhizine hydrochloride (in the concentration of 10.5 micromol x L(-1)) significantly decreased the concentration of glucose in 3T3-L1 adipocytes culture, at the same time improved insulin resistance. These effects are similar to the role of rosiglitazone maleate. CONCLUSION: Rhizoma Coptidis significantly improved insulin resistance, prevented pre-adipocytes differentiation. Its efficacy may be the synergistic effect of various components. Meanwhile, its role in inhibiting differentiation of pre-adipocytes indicates that coptis to increasing glucose uptake dose not cause fat accumulation and weight increasing. This has some clinical significance in the insulin resistance and metabolic syndrome.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Resistência à Insulina , Rizoma/química , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Glucose/metabolismo , Camundongos
20.
Zhonghua Liu Xing Bing Xue Za Zhi ; 28(5): 477-81, 2007 May.
Artigo em Chinês | MEDLINE | ID: mdl-17877179

RESUMO

OBJECTIVE: To investigate the application of the multiple locus variable numbers of tandem repeats (MLVA) in genotype Mycobacterium tuberculosis strains isolated from Tibet, and to understand the characteristics of genotype and distribution. METHODS: 217 M. tuberculosis strains were collected from six regions of Tibet. Twenty tandem repeats loci in the total genome of M. tuberculosis (MTB) were analyzed by PCR and agarose gel electrophoresis method. The characteristics on polymorphism of DNA fingerprinting of 217 MTB strains were analyzed with BioNumerics 3.0 software. RESULTS: 217 M. tuberculosis strains detected with 20 MLVA loci were classified to 19 genotypes with 87.6% of the stains belonging to Beijing genotype and the other 18 genotypes were scattered,accounted for 1.38% and 0.92% strains, respectively. Beijing genotype was not significantly associated with the resistance to all of the four drugs and BCG vaccination. CONCLUSION: It is concluded that the strains of MTB isolated in Tibet present definite polymorphism and most of the epidemic strains belonged to Beijing family genotype and MTB genotyping. The Beijing genotype was not recognized as the one transferred from some of the drug resistance strains or from BCG vaccination. Being a fast and simple technique, MLVA method, seemed a better molecular typing method and could be used for genotyping in M. tuberculosis and monitoring pathogen.


Assuntos
Repetições Minissatélites/genética , Mycobacterium tuberculosis/genética , Vacina BCG , Impressões Digitais de DNA , Eletroforese em Gel de Ágar , Genótipo , Mycobacterium tuberculosis/classificação , Filogenia , Reação em Cadeia da Polimerase , Tibet
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