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1.
J Healthc Eng ; 2023: 7438567, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36704572

RESUMO

Hui Yang Jiu Ji (HYJJ) decoction has been applied as a prescription of traditional Chinese medicine for the treatment of chronic heart failure (CHF). However, its comprehensive molecular mechanism remains unclear now. Our study aimed to explore the possible function and lncRNA-miRNA regulation networks of HYJJ on CHF induced by doxorubicin (DOX) in rats. Our study showed that HYJJ could recover cardiac function and alleviate myocardial injury of DOX-induced CHF. Besides, HYJJ had an effect on restraining myocardial apoptosis in CHF rats. Moreover, RNA-sequencing and bioinformatics analysis indicated that among a total of 548 significantly up- and down-regulated differentially expressed (DE) long noncoding RNA (lncRNA), 511 up- and down-regulated DE miRNAs were identified. Cushing's syndrome and Adrenergic signaling in cardiomyocytes were common pathways between DE-lncRNAs-enriched pathways and DE-miRNAs-enriched pathways. Finally, we observed a new pathway-MSTRG.598.1/Lilrb2 pathway with the HYJJ treatment; however, it needs further studies. In conclusion, this study provided evidence that HYJJ may be a suitable medicine for treating CHF. Moreover, several pivotal miRNAs may serve important roles in these processes by regulating some key miRNAs or pathways in CHF.


Assuntos
Medicamentos de Ervas Chinesas , Insuficiência Cardíaca , MicroRNAs , RNA Longo não Codificante , Animais , Ratos , Doxorrubicina , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Miocárdio/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico
2.
Fish Physiol Biochem ; 42(1): 19-27, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26254257

RESUMO

Fishes display a wide variation in their physiological responses to stress, which is clearly evident in the plasma corticosteroid changes, chiefly cortisol levels in fish. In the present study, we describe a novel label-free immunosensor for detecting plasma cortisol levels. The method is based on immunologic reactions and amperometric measurement using cyclic voltammetry. For the immobilization of the antibody on the surface of sensing electrode, we used a self-assembled monolayer of thiol-containing compounds. Using this electrode, we detect the CV signal change caused by the generation of antigen-antibody complex. The immunosensor showed a response to cortisol levels, and the anodic peak value linearly decreased with a correlation coefficient of 0.990 in diluted plasma. The specificity of the label-free immunosensor system was investigated using other steroid hormones, such as 17α, 20ß-dihydroxy-4-pregnen-3-one, progesterone, estriol, estradiol, and testosterone. The specific detection of cortisol was suggested by a minimal change from -0.32 to 0.51 µA in the anodic peak value of the other steroid hormones. The sensor system was used to determine the plasma cortisol levels in Nile tilapia (Oreochromis niloticus), and the results were compared with those of the same samples determined using the conventional method (ELISA). A good correlation was obtained between values determined using both methods (correlation coefficient 0.993). These findings suggest that the proposed label-free immunosensor could be useful for rapid and convenient analysis of cortisol levels in fish plasma samples.


Assuntos
Técnicas Biossensoriais , Peixes/sangue , Hidrocortisona/sangue , Tilápia/sangue , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Técnicas Eletroquímicas , Eletrodos , Ouro , Hidrocortisona/imunologia , Imunoensaio
3.
Biosens Bioelectron ; 67: 503-10, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25261214

RESUMO

To avoid fish mortality and improve productivity, the physiological conditions including stress state of the cultured fish must be monitored. As an important indicator of stress, glucose concentrations are monitored using in vitro blood analysis. The physiological processes of fish under environmental conditions are harsher in many ways than those experienced by terrestrial animals. Moreover, the process of anaesthetizing and capturing the fish prior to analysis may produce inaccurate results. To solve these problems, we developed wireless biosensor system to monitor the physiological condition of fish. This system enables artificial stress-free and non-lethal analysis, and allows for reliable real-time monitoring of fish stress. The biosensor comprised Pt-Ir wire as the working electrode and Ag/AgCl paste as the reference electrode. Glucose oxidase was immobilized on the working electrode using glutaraldehyde. We used the eyeball interstitial sclera fluid (EISF) as the in vivo implantation site of the sensor, which component concentration correlates well with that of blood component concentration. In the present study, we investigated stress due to alterations in water chemistry, including dissolved oxygen, pH, and ammonia-nitrogen compounds. Stress perceived from behavioural interactions, including attacking behaviour and visual irritation, was also monitored. Water chemistry alterations induced increases in the glucose concentration (stress) that decreased with removal of the stimulus. For behavioural interactions, stress levels change with avoidance, sensory behaviour and activity. We believe that the proposed biosensor system could be useful for rapid, reliable, and convenient analysis of the fish physiological condition and accurately reflects the stress experienced by fish.


Assuntos
Técnicas Biossensoriais , Peixes/fisiologia , Estresse Fisiológico , Tecnologia sem Fio , Amônia/química , Amônia/isolamento & purificação , Animais , Peixes/sangue , Glucose Oxidase/química , Monitorização Fisiológica , Nitrogênio/química , Nitrogênio/isolamento & purificação , Oxigênio/química , Oxigênio/isolamento & purificação
4.
Chemphyschem ; 16(3): 523-7, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25529230

RESUMO

We describe a new strategy to control the reactivity of SeSe bond by using supramolecular chemistry of cucurbituril. We have demonstrated that selenocystamine (SeCy) and cucurbit[6]uril (CB[6]) can form a stable supramolecular complex (Ka =5.5×10(6) M(-1) ). Before complexation, the free SeSe bond in SeCy is rather sensitive to redox stimuli and gets disrupted quickly with addition of reductant or oxidant. However, after binding with CB[6], the SeSe bond becomes quite inert and hardly reacts with reductant or oxidant. One advantage of this supramolecular protection is that it can be applied in a wide pH range from weakly acidic to basic. Additionally, the supramolecular complex formed by SeCy and CB[6] can be reversibly dissociated simply with addition of Ba(2+) .


Assuntos
Compostos Macrocíclicos/química , Selênio/química , Hidrocarbonetos Aromáticos com Pontes/química , Cistamina/análogos & derivados , Cistamina/química , Imidazóis/química , Espectroscopia de Ressonância Magnética , Compostos Organosselênicos/química , Oxirredução , Espectrofotometria Ultravioleta
5.
World J Diabetes ; 4(3): 70-5, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23772275

RESUMO

AIM: To investigate the cytotoxic mechanism of caribbean maitotoxin (MTX-C) in mammalian cells. METHODS: We used whole-cell patch-clamp techniques and fluorescence calcium imaging to determine the cellular toxic mechanisms of MTX-C in insulin secreting HIT-T15 cells, which is a system where the effects of MTX have been observed. HIT-T15 cells stably express L-type calcium current, making it a suitable model for this study. Using the fluorescence calcium indicator Indo-1 AM, we found that there is a profound increase in HIT-T15 intracellular free calcium 3 min after application of 200 nmol/L MTX-C. RESULTS: About 3 min after perfusion of MTX-C, a gradual increase in free calcium concentration was observed. This elevation was sustained throughout the entire recording period. Application of MTX-C did not elicit the L-type calcium current, but large cationic currents appeared after applying MTX-C to the extracellular solution. The current-voltage relationship of the cation current is approximately linear within the voltage range from -60 to 50 mV, but flattened at voltages at -80 and -100 mV. These results indicate that MTX-C induces a non-voltage activated, inward current under normal physiological conditions, which by itself or through a secondary mechanism results in a large amount of cationic influx. The biophysical mechanism of MTX-C is different to its isoform, pacific maitotoxin (MTX-P), when the extracellular calcium is removed. CONCLUSION: We conclude that MTX-C causes the opening of non-selective, non-voltage-activated ion channels, which elevates level of intracellular calcium concentration and leads to cellular toxicities.

6.
Small ; 9(23): 3981-6, 2013 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-23737377

RESUMO

A photoresponsive polyelectrolyte multilayer film containing a diselenide functional group is fabricated using an unconventional layer-by-layer method. The polycation backbone is constructed through copolymerization of di-(1-hydroxylundecyl) diselenide and 1,4-bis(2-hydroxyethyl)piperazine with 2,4-diisocyanatotoluene. A common polyanion poly(styrene sulfonate) is selected as the polyanion. The obtained film can be gradually disrupted under the irradiation of mild visible light, and this process can be monitored with UV-vis spectroscopy. The residue of the film is estimated to be 17% after 5 h of irradiation. The intensity of the visible light can be as low as 50 mW cm⁻², which is even weaker than the sunlight. The cytotoxicity of the building blocks is evaluated in MTT assays using human hepatic cell line (L-02), and the results are satisfactory. Further tests show that cells can grow in a regular manner on this film, indicating good biocompatibility. In addition, the film can be used to achieve cargo loading and controlled release. Considering that light can not only trigger controlled release but also act as part of the therapy itself (photodynamic therapy), this system shows hope for further development into a platform for the combination of chemotherapy and photodynamic therapy, especially for applications concerning skin.


Assuntos
Luz , Fotoquimioterapia/métodos , Polímeros/química , Linhagem Celular , Humanos
7.
Fish Physiol Biochem ; 39(2): 299-308, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22864705

RESUMO

Maintaining high-quality fish eggs stably and efficiently is important for aquaculture. We developed a label-free immunosensor system for measuring 17,20ß-dihydroxy-4-pregnen-3-one (DHP). DHP is suddenly secreted before ovulation as a maturation-inducing hormone in fish, and therefore, DHP levels are an indicator for predicting ovulation. The method is based on immunologic reactions and amperometric measurement using cyclic voltammetry (CV). For biomolecular immobilization on the surface of sensing electrode, Au electrode, we used self-assembled monolayers of thiol-containing compounds to fix anti-DHP immunoglobulin. In addition, we used a single-walled carbon nanotube to improve sensitivity. Using this electrode, we were able to determine the CV signal change caused by the antigen-antibody complex. The proposed immunosensor system showed a linear correlation (correlation coefficient: 0.9827) between the anodic peak current of the CV and the DHP level in range from 15.6 to 50,000 pg ml(-1). The sensor system was then applied to monitor DHP of goldfish (Carassius auratus). Blood plasma of fish was collected every 3 h after administering a DHP inducer. In the measurement, the anodic peak current of the CV showed distinct changes depending on DHP levels in the blood plasma. A good relationship was observed between DHP levels determined by our proposed system and the conventional method (correlation coefficient: 0.9351).


Assuntos
Aquicultura/métodos , Técnicas Eletroquímicas/veterinária , Carpa Dourada/metabolismo , Hidroxiprogesteronas/análise , Nanotubos de Carbono , Ovulação/metabolismo , Animais , Eletrodos , Feminino , Hidroxiprogesteronas/imunologia , Imunoensaio/métodos , Imunoensaio/veterinária , Estrutura Molecular
8.
Sensors (Basel) ; 12(5): 6269-81, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22778641

RESUMO

We have developed a wireless biosensor system to continuously monitor L-lactic acid concentrations in fish. The blood L-lactic acid level of fish is a barometer of stress. The biosensor comprised Pt-Ir wire (φ0.178 mm) as the working electrode and Ag/AgCl paste as the reference electrode. Lactate oxidase was immobilized on the working electrode using glutaraldehyde. The sensor calibration was linear and good correlated with L-lactic acid levels (R = 0.9959) in the range of 0.04 to 6.0 mg · dL(-1). We used the eyeball interstitial sclera fluid (EISF) as the site of sensor implantation. The blood L-lactic acid levels correlated closely with the EISF L-lactic acid levels in the range of 3 to 13 mg · dL(-1) (R = 0.8173, n = 26). Wireless monitoring of L-lactic acid was performed using the sensor system in free-swimming fish in an aquarium. The sensor response was stable for over 60 h. Thus, our biosensor provided a rapid and convenient method for real-time monitoring of L-lactic acid levels in fish.


Assuntos
Ácido Láctico/metabolismo , Ondas de Rádio , Tilápia/metabolismo , Animais , Técnicas Biossensoriais , Calibragem , Eletrodos , Concentração de Íons de Hidrogênio , Ácido Láctico/sangue , Reprodutibilidade dos Testes , Natação , Temperatura , Tilápia/fisiologia
9.
Anal Bioanal Chem ; 403(4): 1187-90, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22427105

RESUMO

We have developed a mediator-type biosensor to rapidly monitor blood glucose concentrations in fish, which are an indicator of stress. Glucose oxidase was used to detect glucose concentrations and ferrocene was used to limit the effect of oxygen. We also improved the sensitivity and durability of the sensor for better performance. Single-walled carbon nanotubes were used to enhance sensor sensitivity. Affixing the carbon nanotubes (30 mg ml(-1)) to the working electrode increased the sensor sensitivity to 61.9 mM nA(-1) mm(-2), twice the value for the sensor without single-walled carbon nanotubes. A fabricated mediator-type biosensor sensor was used to perform real-time in vivo measurements. The sensor was implanted into the interstitial fluid of a fish eyeball, and detection was transmitted to a personal computer by a wireless potentiostat. Continuous measurement of the glucose concentration was possible for 78 hours. Stress was artificially applied to the fish during the measurement, and the change of blood glucose concentrations were observed. Our proposed sensor is applicable for effectively monitoring stress in free-swimming fish.


Assuntos
Técnicas Biossensoriais/métodos , Peixes/fisiologia , Glucose/análise , Monitorização Fisiológica/métodos , Nanotubos de Carbono/química , Animais , Técnicas Biossensoriais/instrumentação , Glucose/metabolismo , Glucose Oxidase/análise , Estresse Fisiológico
10.
Langmuir ; 26(18): 14414-8, 2010 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-20722431

RESUMO

We have fabricated a polymeric superamphiphile based on the electrostatic interaction between the double hydrophilic block copolymer of poly(ethylene glycol)-b-acrylic acid (PEG-b-PAA) and a selenium-containing surfactant (SeQTA). The polymeric superamphiphiles are able to self-assemble to form micelles in solution. The micelles can be disassembled with the addition of 0.1% H(2)O(2) because SeQTA is very sensitive to oxidation. The selenide group in SeQTA is oxidized into selenoxide (SeQTA-Ox) by H(2)O(2), which makes the surfactant more hydrophilic, thus leading to the disassembly of the micelles. In addition, small guest molecules such as fluorescein sodium can be loaded into the micelles made from the polymeric superamphiphiles and released in a controlled way under mild oxidation conditions. This study represents a new way to fabricate stimuli-responsive superamphiphiles for controlled self-assembly and disassembly.


Assuntos
Resinas Acrílicas/química , Interações Hidrofóbicas e Hidrofílicas , Micelas , Compostos Organosselênicos/química , Polietilenoglicóis/química , Polímeros/química , Fluoresceína/química , Oxirredução , Soluções , Eletricidade Estática , Tensoativos/química
11.
Talanta ; 80(2): 909-15, 2009 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19836572

RESUMO

The rapidly increasing demand for cultured fish as a food resource requires simple, effective methods for controlling fish health in culture conditions. Plasma total cholesterol levels are significantly related to fish mortality following bacterial challenge, and are thus a good indicator of the general health of fish. We developed a wireless biosensor system to continuously monitor the total cholesterol concentration in fish (Nile tilapia, Oreochromis niloticus). The biosensor was constructed with Pt-Ir wire (phi0.178 mm) as the working electrode and Ag/AgCl paste as the reference electrode. Cholesterol oxidase and cholesterol esterase were immobilized on the working electrode using glutaraldehyde. The sensor output was linear and strongly correlated with the cholesterol level (R=0.9970) in the range of 2.65-403 mg dl(-1). This range covers the range of total cholesterol levels in fish. To avoid blood coagulation and proteins coalescing on the sensor, we implanted the sensor in the fluid under the scleral surface of the eyeball (EISF). The EISF is presumed to reflect the levels of most blood components and does not include the substances contained in blood that inhibit sensor measurement. Total cholesterol concentrations in blood and EISF were strongly correlated (R=0.8818, n=72) in the blood total cholesterol range of 74-480 mg dl(-1). Therefore, we used EISF as an alternative to blood and performed continuous in vivo-monitoring of the total cholesterol concentration in fish. We also investigated the application of the calibration method and wireless monitoring system. These applications enabled us to securely monitor total cholesterol levels in free-swimming fish in an aquarium for over 40 h. Thus, our newly developed sensor provided a rapid and convenient method for real-time monitoring of total cholesterol concentrations in free-swimming fish.


Assuntos
Técnicas Biossensoriais/métodos , Colesterol/sangue , Ciclídeos/sangue , Técnicas Eletroquímicas/métodos , Algoritmos , Animais , Técnicas Biossensoriais/instrumentação , Calibragem , Colesterol/química , Colesterol/metabolismo , Colesterol Oxidase/química , Colesterol Oxidase/metabolismo , Técnicas Eletroquímicas/instrumentação , Eletrodos Implantados , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Peróxido de Hidrogênio/química , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/métodos , Reprodutibilidade dos Testes , Compostos de Prata/química , Esterol Esterase/química , Esterol Esterase/metabolismo , Natação
12.
Anal Chim Acta ; 633(1): 90-6, 2009 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-19110121

RESUMO

A biosensor system was developed for continuous estimation of blood glucose in fish. Because it is difficult to measure blood components in real-time due to decreased sensor output resulting from blood coagulation and coalescing blood proteins at the sensor placement site, we used the eyeball scleral interstitial fluid (EISF) as the site of sensor implantation. Evaluation of the relationship between EISF and blood glucose concentrations revealed that the blood glucose concentration correlated closely with the EISF glucose concentration (y=2.2996+0.9438x, R=0.960, n=112). To take advantage of the close correlation between blood and EISF glucose, we prepared a needle-type enzyme sensor for implantation in the fish sclera using a flexible wire electrode. The sensor provided a rapid response, good linearity, and reproducibility. Continuous glucose monitoring could be carried out by implanting this needle-type glucose sensor onto the eye. The findings indicated that the glucose concentration increased with sensor output current over time, and that changes in the blood glucose were continuously reflected in the EISF. The glucose concentration was estimated based on the one-point or two-point calibration methods. The two-point calibration method yielded the most accurate glucose monitoring (blood glucose range of 70-420 mg dL(-1)) over 160 min. Sensor-estimated glucose and whole blood glucose values were highly correlated (y=0.4401+0.8656x, R=0.958).


Assuntos
Técnicas Biossensoriais/instrumentação , Glicemia/análise , Peixes/sangue , Animais , Técnicas Biossensoriais/métodos , Calibragem , Líquido Extracelular/química , Concentração de Íons de Hidrogênio , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Reprodutibilidade dos Testes , Temperatura
13.
Biosens Bioelectron ; 24(5): 1417-23, 2009 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-18929477

RESUMO

Periodic checks of fish health and the rapid detection of abnormalities are thus necessary at fish farms. Several studies indicate that blood glucose levels closely correlate to stress levels in fish and represent the state of respiratory or nutritional disturbance. We prepared a wireless enzyme sensor system to determine blood glucose levels in fish. It can be rapidly and conveniently monitored using the newly developed needle-type enzyme sensor, consisting of a Pt-Ir wire, Ag/AgCl paste, and glucose oxidase. To prevent the effects of interfering anionic species, such as uric acid and ascorbic acid, on the sensor response, the Pt-Ir electrode was coated with Nafion, and then glucose oxidase was immobilized on the coated electrode. The calibration curve of the glucose concentration was linear, from 0.18 to 144mg/dl, and the detection limit was 0.18mg/dl. The sensor was used to wirelessly monitor fish glucose levels. The sensor-calibrated glucose levels and actual blood glucose levels were in excellent agreement. The fluid of the inner sclera of the fish eyeball (EISF) was a suitable site for sensor implantation to obtain glucose sample. There was a close correlation between glucose concentrations in the EISF and those in the blood. Glucose concentrations in fish blood could be monitored in free-swimming fish in an aquarium for 3 days.


Assuntos
Técnicas Biossensoriais/métodos , Glicemia/análise , Eletroquímica/instrumentação , Peixes/metabolismo , Glucose Oxidase/química , Monitorização Ambulatorial/instrumentação , Telemetria/instrumentação , Animais , Técnicas Biossensoriais/instrumentação , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Glicemia/química , Sistemas Computacionais , Desenho de Equipamento , Análise de Falha de Equipamento , Monitorização Ambulatorial/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Telemetria/métodos
14.
Anal Bioanal Chem ; 391(4): 1147-52, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18438648

RESUMO

Bacterial cold water disease, caused by Flavobacterium psychrophilum, is a serious problem in the aquaculture industry worldwide. Several methods to prevent and treat cold water disease have been studied. Although detection at the early stage of F. psychrophilum infection is very important for the prevention and treatment of cold water disease, an effective detection method has not yet been developed. The use of flow cytometry (FCM) for the rapid determination of bacterial cell numbers with high sensitivity is beginning to attract attention. Immunomagnetic separation (IMS) has also been used to detect F. psychrophilum. The purpose of the present study was to develop a method to quickly determine the number of bacterial cells by combining the FCM and IMS methods. Because samples can be more effectively concentrated using smaller magnetic beads and stronger magnetism, we used carbonyl iron powder as the magnetic beads for the IMS. The detection level of F. psychrophilum using FCM combined with IMS was 5 orders lower than that using FCM without IMS. The values determined using FCM combined with IMS strongly correlated with those obtained using the colony-counting method, in the range of approximately 10-10(8) colony-forming units per milliliter. One FCM assay could be completed within 60 s and the total assay time, including sample preparation, was less than 2 h. The combined method of FCM with IMS developed in this study can be used reliably for the rapid detection of F. psychrophilum.


Assuntos
Flavobacterium/imunologia , Flavobacterium/isolamento & purificação , Citometria de Fluxo/métodos , Separação Imunomagnética/métodos , Compostos Carbonílicos de Ferro/química , Anticorpos/sangue , Anticorpos/imunologia , Especificidade de Anticorpos , Contagem de Colônia Microbiana , Flavobacterium/química , Espectrometria de Fluorescência , Fatores de Tempo
15.
Anal Bioanal Chem ; 391(4): 1255-61, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18236032

RESUMO

L-lysine (L-Lys) in living bodies is critical for metabolism; therefore, determination of its levels in food is important. Most enzymatic methods for L-Lys analysis are performed using L-lysine oxidase (LyOx), but commercially manufactured LyOx is generally not highly selective for L-Lys among amino acids. We previously isolated LyOx as an antibacterial protein secreted from the skin of the rockfish Sebastes schlegeli. In the present study, we developed an optical enzyme sensor system for rapid and continuous determination of L-Lys using this LyOx. The system comprised an immobilized LyOx membrane, an optical oxygen probe, a flow system, and a personal computer. The amount of L-Lys was detected as a decrease in the oxygen concentration due to the LyOx reaction. The specificity of the sensor was examined against various amino acids. The sensor response was specific for L-Lys. Good reproducibility was obtained in 58 assays. The response of the sensor using commercially prepared LyOx was unstable compared with the response using LyOx isolated in our laboratory. Our sensor system could be used for 5 weeks without our having to change the enzyme membrane. The calibration curve for a standard L-Lys solution was linear from 0.1 to 3.0 mmol L(-1). One assay could be completed within 2 min. The sensor was applied to determine the L-Lys content in food samples such as bonito cooking water and scallop hepatopancreas. The values obtained using the sensor and conventional high-performance liquid chromatography methods were well correlated.


Assuntos
Aminoácido Oxirredutases/metabolismo , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Enzimas Imobilizadas/metabolismo , Peixes/metabolismo , Lisina/análise , Lisina/metabolismo , Animais , Calibragem , Enzimas Imobilizadas/química , Oxirredução , Reprodutibilidade dos Testes , Especificidade por Substrato
16.
Microbiol Res ; 162(2): 130-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16520028

RESUMO

The viable but nonculturable (VBNC) suppression mutant formed platable cells at low temperature stress after inoculation in artificial seawater (ASW). Suppression subtractive hybridization was used to identify differentially expressed genes among cDNAs of the VBNC suppression mutant and the wild-type Vibrio vulnificus strain. Glutathione S-transferase was identified as a responsive gene of the VBNC suppression mutant in our assay, and was highly expressed from the VBNC suppression mutant at low temperature stress. Culturability tests revealed that the wild-type cells were sensitive to oxidative stress in the hydrogen peroxide (H(2)O(2)) and to 1-chloro-2,4-dinitrobenzene (CDNB) compared with the VBNC suppression mutant cells. Adding glutathione showed that many wild-type V. vulnificus cells maintained culturability in cold ASW. These results suggest that non-nutritional growth inhibitors, such as peroxide that accumulates at low temperatures, influence VBNC in V. vulnificus cells.


Assuntos
Vibrio vulnificus/fisiologia , Microbiologia da Água , Temperatura Baixa , Dinitroclorobenzeno/farmacologia , Glutationa Transferase/biossíntese , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Guanidinas/farmacologia , Peróxido de Hidrogênio/farmacologia , Mutação , Hibridização de Ácido Nucleico , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vibrio vulnificus/enzimologia , Vibrio vulnificus/genética , Vibrio vulnificus/isolamento & purificação
17.
Biosens Bioelectron ; 22(9-10): 1916-9, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16996256

RESUMO

Flavobacterium psychrophilum, the causative agent of bacterial cold-water disease (BCWD), was originally isolated from coho salmon Oncorhychus kisutch in the USA. Bacterial cold-water disease has since been spreading throughout Japan and has caused serious damage to populations of ayu Plecoglossus altivel in many farms and rivers. The rapid method of detecting for F. psuchrophilum is requested, however, traditional methods are laborious because of complicated assay procedures. In this study, a rapid method of detecting F. psychrophilum was developed using a modified method of flow cytometry (FCM) analysis and immunomagnetic separation (IMS). Magnetic iron, in small particles, was prepared by the reaction of a mixture of ferric and ferrous ions under alkaline conditions. The particles were coated with antiserum against F. psychrophilum by dextran. Polyclonal antibodies (anti-F. psychrophilum) conjugated with fluorescein isothiocyanate (FITC) were reacted with F. psychrophilum, and then prepared immunomagnetic were applied using IMS, followed by FCM determination. A good correlation was observed between the cell numbers determined by the FCM method and the traditional method in the range of 10(2)-10(8) cells ml(-1). The FCM analysis could count cells within 1min, and the total analysis time, including sample preparation, was less than 2 h.


Assuntos
Separação Celular , Flavobacterium/isolamento & purificação , Citometria de Fluxo , Separação Imunomagnética , Ferro , Nanopartículas Metálicas
18.
Anal Chim Acta ; 573-574: 117-24, 2006 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-17723514

RESUMO

A needle-type biosensor system was developed for rapid and simple determination of glucose levels in fish blood. The sensor comprises a needle-type hollow container (18-gauge needle), immobilized enzyme membrane and optic fiber probe with ruthenium complex. The enzyme membrane was prepared from glucose oxidase, azide-unit pendant water-soluble photopolymer and an ultra-thin dialysis membrane. The optic fiber probe was inserted into the rolled enzyme membrane placed in the needle-type hollow container. The calibration curve was linear for glucose levels in fish plasma. One assay was completed within 3 min. A good reproducibility was observed for 60 times without exchange of the enzyme membrane. The sensor was inserted into the caudal vein of fish to measure blood glucose levels. The sensor responded immediately after insertion and glucose levels could be monitored. Good correlations were observed between values determined using the sensor and conventional methods in the range of 48-157 mg dl(-l) (correlation coefficient, 0.9474).

19.
Anal Chim Acta ; 573-574: 158-63, 2006 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-17723519

RESUMO

Listeria monocytogenes can grow at the low temperature commonly used in the storage and transportation of food, and the number of cases of food poisoning caused by L. monocytogenes has increased recently in the US and Europe. Several methods of detecting L. monocytogenes cells have been proposed; however, all existing methods require approximately 48 h incubation. In this study, we attempted rapid detection of L. monocytogenes using flow cytometry (FCM). The method is based on measuring the number of L. monocytogenes cells by using a combination of FCM and immunomagnetic separation (IMS). First, polyclonal antibodies (anti-L. monocytogenes rabbit IgG-FITC) conjugated with fluorescein isothiocyanate (FITC) were reacted with L. monocytogenes cells, and then FCM was applied. The cell numbers were determined by FCM using a traditional colony-counting method in the range of 10(4)-10(8) cells ml(-1). Tetrameric antibody complexes (TAC) were used because they can recognize both magnetic and FITC molecules on the FITC-conjugated antibodies. FITC-labeled L. monocytogenes cells were reacted with a secondary antibody (TAC) bound to magnetic beads. Then, IMS was used. The method is suitable for detection in the range of 10(2)-10(8)cells ml(-1). The FCM assay enumerated the cells within 1 min and the total assay time, including sample preparation, was less than 2 h.

20.
Toxicol Mech Methods ; 16(8): 411-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-20021015

RESUMO

The effects of two natural ingredients, Chinese parsley (CP) and chitosan (CT), on growth, accumulation, and excretion of cadmium in fish body and preservation of essential trace metals in the body were investigated by using rainbow trout that had been fed cadmium-added diet, low and high concentration, for 3 weeks. This pretest confirmed that cadmium was accumulated in the liver, kidney, and intestine of the test fish. The cadmium level of the fish, fed diet with CP or CT, was decreased by 18% and 24%, respectively, compared to that of the fish given the control diet. But CP and CT did not have an influence on normal growth of test fish and the levels of essential trace metals in the body. In addition, the level of cadmium was higher in liver than kidney in the high-cadmium dietary group, indicating the Cd level in kidney follows that of liver as kidney lies in the final stage of metabolism. The cadmium accumulation in the fish body was supposed to be reduced, by giving CP to increase the solubility of Cd to body fluid by conjugation into metallothioneins (MTs), while CT was supposed to be responsible for the physical adsorption of cadmium ions by glucosamine groups.

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