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1.
Braz. j. biol ; 75(4,supl.1): 45-51, Nov. 2015. tab, graf
Artículo en Inglés | LILACS | ID: lil-768230

RESUMEN

Abstract The aim of the present study was to evaluate the potential use of otolith microchemistry (Sr:Ca and Ba:Ca ratios) to identify silver mullet, Mugil curema, populations in Southeastern Caribbean Sea. Fish samples were collected in 7 areas of Nueva Esparta State (Venezuela). The otolith Sr:Ca and Ba:Ca ratios and water Sr:Ca were determined (by ICP-OES and EDTA volumetric method). Otoliths Sr:Ca and Ba:Ca ratios and Sr:Ca partition coefficient of mullets in Cubagua island (south of the State) were significantly different from ratios in La Guardia (north of the State). A discriminant analysis of otolith Sr:Ca and Ba:Ca ratios separated Cubagua Island from La Guardia values. These results suggest the existence of different mullet groups in the Southeastern Caribbean Sea. For this, the simultaneous use of Sr:Ca and Ba:Ca ratios could be a potential tool to identify populations in the study area.


Resumo O objetivo do presente estudo foi avaliar o potencial uso da microquímica do otólito (razões Sr:Ca e Ba:Ca) para identificar distintas populações de tainha, Mugil curema, no sudeste do mar caribenho. Os peixes foram coletados em 7 áreas do estado de Nueva Esparta (Venezuela). As razões Sr:Ca e Ba:Ca do otólito e a razão Sr:Ca da água foram determinadas (pelo ICP-OES e EDTA método volumétrico). As razões de Sr:Ca e Ba:Ca dos otólitos e o coeficiente de partição das tainhas da Ilha Cubagua (sul do estado) foram significativamente diferentes das razões de La Guardia (norte do estado). A análise discriminante das razões de Sr:Ca e Ba:Ca dos otólitos separa os valores da Ilha Cubagua e de La Guardia. Estes resultados sugerem a existência de diferentes grupos de Mugil curema no sudeste do mar Caribenho e que o uso simultâneo das razões Sr:Ca e Ba:Ca poderiam ser uma potencial ferramenta para identificar as populações da área de estudo.


Asunto(s)
Animales , Bario/análisis , Calcio/análisis , Membrana Otolítica/química , Smegmamorpha/fisiología , Estroncio/análisis , Región del Caribe , Ecosistema , Microquímica , Dinámica Poblacional , Venezuela
2.
Artículo en Inglés | IMSEAR | ID: sea-153786

RESUMEN

Wide spread use of Di-(2-ethylhexyl) phthalate (DEHP) has made it a ubiquitous contaminant in today’s environment, responsible for possible carcinogenic and endocrine disrupting effects. In the present investigation an integrative toxico-proteomic approach was made to study the estrogenic potential of DEHP. In vitro experiments carried out with DEHP (0.1-100 μM) induced proliferations (E-screen assay) in human estrogen receptors-α (ERα) positive MCF-7 and ERα negative MDA-MB-231 breast cancer cells irrespective of their ERα status. Further, DEHP suppressed tamoxifen (a potent anti-breast cancer drug) induced apoptosis in both cell types as shown by flowcytometric cell cycle analysis. Label-free quantitative proteomics analysis of the cell secretome of both the cell lines indicated a wide array of stress related, structural and receptor binding proteins that were affected due to DEHP exposure. The secretome of DEHP treated MCF-7 cells revealed the down regulation of lactotransferrin, an ERα responsive iron transport protein. The results indicated that toxicological effects of DEHP did not follow an ERα signaling pathway. However, the differential effects in MCF-7 and MDA-MB-231 cell lines indicate that ERα might have an indirect modulating effect on DEHP induced toxicity.


Asunto(s)
Apoptosis/efectos de los fármacos , Neoplasias de la Mama/patología , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular Tumoral/efectos de los fármacos , Línea Celular Tumoral/metabolismo , Dietilhexil Ftalato/toxicidad , Contaminantes Ambientales/toxicidad , Receptor alfa de Estrógeno/efectos de los fármacos , Receptor alfa de Estrógeno/fisiología , Estrógenos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Lactoferrina/biosíntesis , Lactoferrina/genética , Lactoferrina/metabolismo , Células MCF-7/efectos de los fármacos , Células MCF-7/metabolismo , Espectrometría de Masas/instrumentación , Microquímica/instrumentación , Proteínas de Neoplasias/efectos de los fármacos , Proteínas de Neoplasias/fisiología , Proteínas de Neoplasias/metabolismo , Neoplasias Hormono-Dependientes/patología , Proteómica , Tamoxifeno/antagonistas & inhibidores , Tamoxifeno/farmacología
3.
Egyptian Journal of Histology [The]. 2012; 35 (1): 1-3
en Inglés | IMEMR | ID: emr-126537

RESUMEN

Nanotechnology means technological developments on a nanometer scale, usually 0.1-100nm. The application of nanotechnology in medicine offers impressive solutions for various life-threatening diseases. nanoparticle -carrying drugs can 'target' the drug to the parts of the body where it is needed, can escape uptake by the immune system and can cross biological barriers. Hence, providing reduced drug side effects and improved drug efficacy. With the advances in the field of nanotechnology, manufacture of nanorobot is expected to be created in the next 10 years. this automatic molecular machine can swim in human blood, can view full cellular details, can monitor levels of different compounds, and can store that information. This device can also be used to deliver drugs or perform wireless intracellular and intranuclear surgery. Nanotissue samples can be taken as well. Nanomedicine can hopefully conquer human disease, illhealth, and aging


Asunto(s)
Microquímica , Nanoestructuras , Nanomedicina
4.
Biol. Res ; 44(1): 43-51, 2011. ilus
Artículo en Inglés | LILACS | ID: lil-591863

RESUMEN

After the progress made during the genomics era, bioinformatics was tasked with supporting the flow of information generated by nanobiotechnology efforts. This challenge requires adapting classical bioinformatic and computational chemistry tools to store, standardize, analyze, and visualize nanobiotechnological information. Thus, old and new bioinformatic and computational chemistry tools have been merged into a new sub-discipline: nanoinformatics. This review takes a second look at the development of this new and exciting area as seen from the perspective of the evolution of nanobiotechnology applied to the life sciences. The knowledge obtained at the nano-scale level implies answers to new questions and the development of new concepts in different fields. The rapid convergence of technologies around nanobiotechnologies has spun off collaborative networks and web platforms created for sharing and discussing the knowledge generated in nanobiotechnology. The implementation of new database schemes suitable for storage, processing and integrating physical, chemical, and biological properties of nanoparticles will be a key element in achieving the promises in this convergent field. In this work, we will review some applications of nanobiotechnology to life sciences in generating new requirements for diverse scientific fields, such as bioinformatics and computational chemistry.


Asunto(s)
Humanos , Disciplinas de las Ciencias Biológicas , Biología Computacional/tendencias , Microquímica , Informática Médica/métodos , Nanotecnología/tendencias , Simulación por Computador , Modelos Moleculares , Informática Médica/tendencias
5.
Acta Pharmaceutica Sinica ; (12): 640-644, 2009.
Artículo en Chino | WPRIM | ID: wpr-278205

RESUMEN

This study is to investigate the effect of Cordyceps sinensis and its cultured mycelia on growth and metabolism of Escherichia coli, and microcalorimetric method was carried out to evaluate its biological activity. The study will provide the basis for the quality control of Cordyceps sinensis. Experimental result will show the effect of natural Cordyceps sinensis and its cultured mycelia on growth and metabolism of Escherichia coli, with index of P(1max) and effective rate (E) by microcalorimetry, the data of experiment were studied by cluster analysis. The results showed that Cordyceps sinensis and its cultured mycelia not only can promote growth and metabolism of Escherichia coli but also can regulate the balance of intestinal microecology efficiently. When the concentrations of samples > 6.0 mg mL(-1), natural Cordyceps sinensis can promote the growth and metabolism of Escherichia coli efficiently (P < 0.05) compared with the control group, and have better dose-effect relationship with concentration (r > 0.9), its cultured mycelia does not show conspicuous auxoaction (P > 0.05) and have not dose-effect relationship with concentration (r < 0.6); when the concentration of samples < 6.0 mg mL(-1), all samples does not show conspicuous auxoaction (P > 0.05). Natural Cordyceps sinensis and its cultured mycelia can be distinguished by cluster analysis. Microcalorimetry has a good prospect on the quality evaluation of the traditional Chinese medicine.


Asunto(s)
Productos Biológicos , Farmacología , Calorimetría , Métodos , Cordyceps , Escherichia coli , Microquímica , Métodos , Micelio
6.
Clinics ; 62(3): 215-224, June 2007. tab, graf
Artículo en Inglés | LILACS | ID: lil-453280

RESUMEN

OBJECTIVE: To evaluate the analytical micromethod using liquid chromatography for the quantification of propranolol in children submitted to surgery of tetralogy of Fallot (TLF). Methods: Only 0.2 mL of plasma is required for the assay. Peaks eluted at 8.4 (Propranolol) and 17.5 min (verapamil, internal standard) from a C18 column, with a mobile phase 0.1 M acetate buffer, pH 5.0, and acetonitrile (60:40, v/v) at flow rate 0.7 mL/min, detected at 290 nm (excitation) and 358 nm (emission). Surgery was started 776 min of drug administration (8.7mg, mean); seven blood samples were collected from six patients (4M/2F; 2.1yrs;11.5kg; 0.80m; 18.9kg/m²). RESULTS: Confidence limits of the method showed high selectivity and recovery, sensitivity of 0.02ng/mL, good linearity (0.05-1000ng/mL), precision of 8.6 percent and accuracy of 3.1 percent. The mean duration of surgery was 283.2min, with the patients remaining under cardiopulmonary bypass (CPB) for 114min. A declining curve of propranolol plasma concentration was obtained after the last dose in the night that preceded the day of surgery. Plasma concentration also was normalized with hematocrit due to the hemodilution caused by the CPB procedure. On the other hand a decrease on drug plasma concentration was obtained between periods, the beginning of surgery to the postoperative day 2 (7.09 ng/mL and 0.05 ng/mL, p<0.05 respectively) and from the end of CPB to the postoperative day 2 (2.79ng/mL e 0.05ng/mL, p<0.05). CONCLUSION: Propranolol monitoring of plasma concentrations of children (TLF) normalized after the last preoperative dose revealed a decline from the beginning of surgery to the second postoperative day, suggesting that, once redistribution was restored, propranolol washout was complete.


OBJETIVO: Avaliar o micrométodo analítico empregando a cromatografia líquida para quantificação de propranolol em crianças operadas de tetralogia de Fallot (TLF). MÉTODO: Requereu-se apenas volumes de 0,2mL de plasma para a realização do ensaio. Os picos foram eluídos em 8.4 (Propranolol) e 17.5 min (verapamil, padrão interno) de uma coluna C18, com fase móvel (tampão acetato 0,1 M pH 5,0 e acetonitrila, 60:40, v/v) em fluxo de 0,7 mL/min, sendo detectados em 290 nm (excitação) e em 358 nm (emissão). A cirurgia iniciou-se 776 min depois da dose administrada (8,7mg, média) e sete amostras de sangue foram coletadas de seis pacientes (4M/2F; 2,1 anos;11,5kg; 0,80m;18,9kg/m²). RESULTADOS: Os limites de confiança do método analítico evidenciaram alta seletividade e recuperação, sensibilidade (0,02ng/mL), boa linearidade (0,05-1000ng/mL), precisão de 8,6 por cento e exatidão de 3,1 por cento. A duração média da cirurgia foi de 283,2min, com os pacientes em circulação extracorpórea (CEC) durante 114min. Uma curva de declínio do propranolol no plasma foi obtida após a última dose na noite que precedeu o dia da intervenção. A concentração plasmática foi normalizada com o hematócrito devido à hemodiluição causada pela CEC. Por outro lado obteve-se decréscimo nas concentrações plasmáticas entre os períodos início da cirurgia para o 2° dia de pós-operatório (7,09 ng/mL e0,05 ng/mL, p<0,05 respectivamente) e do final da CEC para o 2° dia de pós-operatório (2,79ng/mL e 0,05ng/mL, p<0,05). CONCLUSÃO: O monitoramento das concentrações plasmáticas normalizadas do propranolol, em crianças com TLF, após a última dose pré-operatória revelou decaimento do início da cirurgia para o segundo pós-operatório, sugerindo que após a correção cirúrgica, uma vez restaurada a distribuição, a eliminação do fármaco foi completa.


Asunto(s)
Preescolar , Femenino , Humanos , Lactante , Masculino , Microquímica/métodos , Propranolol/sangre , Tetralogía de Fallot/cirugía , Vasodilatadores/sangre , Cromatografía Líquida de Alta Presión , Monitoreo de Drogas/métodos , Atención Perioperativa , Propranolol/farmacocinética , Propranolol/uso terapéutico , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tetralogía de Fallot/sangre , Vasodilatadores/farmacocinética , Vasodilatadores/uso terapéutico
7.
Rev. invest. clín ; 58(3): 190-197, June-May- 2006. ilus, tab
Artículo en Inglés | LILACS | ID: lil-632349

RESUMEN

Background. In Mexico, diabetes mellitus type 2 and hypertension are leading causes of end-stage renal disease. Diagnosis of early renal damage with detection of microalbuminuria (microAlbU) is fundamental for treatment and prevention, and so avoiding the catastrophes of renal failure. For screening purposes, several simplified tests, including dipstick methods, fulfill the accuracy requirements for microAlbU detection compared with gold standards; however, no study has established the reliability of such tests in our setting. Aim. To evaluate the utility of micraltest II TM as a screening test for microAlbU compared with nephelometry in patients with diabetes mellitus type 2 and non-diabetic patients with essential hypertension. Patients and methods. Patients with diabetes mellitus type 2 as well as patients with essential hypertension of any age, sex and time of evolution, attending to three primary health-care units (UMF No. 3, 92 and 93, Guadalajara, Jalisco) were included. Patients with transitory albuminuria, secondary hypertension and serum creatinine > 2 mg/dL were excluded. Micraltest II TM was performed in the first morning urine sample, and nephelometry was performed in a 24-h urine collection. Diagnostic accuracy of the dipstick test was then determined. Results. 245 patients were studied: 71 (29%) were diabetics without hypertension, 95 (39%) were diabetics with hypertension, and 79 (32%) had only essential hypertension. In diabetic patients, micraltest II TM sensitivity was 83%, specificity 96%, and positive and negative predictive values were 95% and 88%, respectively. Correlation between nephelometry and micraltest II TM results was 0.81 (p < 0.001). The best cut-off point for microAlbU was 30.5 mg/L, and area under the curve (± SEM) was 0.91 ± 0.03 (confidence interval 95%: 0.85-0.96). In non-diabetic patients with essential hypertension, micraltest II TM sensitivity was 75%, specificity 95%, and positive and negative predictive values were 43% and 99%, respectively. Correlation between nephelometry and micraltest II TM results was 0.43 (p < 0.001). The best cut-off point for microAlbU was 28.2 mg/L, and area under the curve was 0.85 ± 0.13 (0.60-1.10). Conclusion. Micraltest II TM dispstick is a rapid, valid and reliable method for albuminuria screening in patients with diabetes mellitus type 2 and in those non-diabetic patients with essential hypertension in our setting.


Antecedentes. En México, la diabetes mellitus tipo 2 y la hipertensión son las principales causas de insuficiencia renal crónica terminal. El diagnóstico temprano con detección de microalbuminuria (microAlbU) es fundamental para el tratamiento y prevención, y así evitar las catástrofes de la falla renal. Con el fin de tamizaje, varias pruebas simples, incluyendo las tiras reactivas, cumplen con los requerimientos de exactitud para detección de microAlbU comparados con esténdares de oro; sin embargo, ningún estudio ha establecido la confiabilidad de dichos métodos en nuestro medio. Objetivo. Evaluar la utilidad del micraltest II TM como prueba de tamizaje para microAlbU comparada con nefelometría en pacientes con diabetes mellitus tipo 2 y pacientes no diabáticos con hipertensión arterial esencial. Pacientes y métodos. Se incluyeron pacientes con diabetes mellitus tipo 2, así como pacientes con hipertensión arterial esencial de cualquiera de los dos sexos, sexo y tiempo de evolución que atendían a tres unidades de Medicina Familiar (UMF No. 3, 92 y 93, Guadalajara, Jalisco). Se excluyeron pacientes con albuminuria transitoria, hipertensión secundaria y creatinina sárica > 2 mg/dL. El micraltest II TM se realizó en la primera muestra matutina de orina, y la nefelometría en recolecciones de orina de 24 horas. La exactitud diagnóstica de la tira reactiva fue luego determinada. Resultados. Doscientos cuarenta y cinco pacientes fueron estudiados: 71 (29%) eran diabáticos sin hipertensión, 95 (39%) eran diabáticos con hipertensión, y 79 (32%) tenían sólo hipertensión arterial esencial. En los pacientes diabáticos, el micraltest II TM tuvo una sensibilidad de 83%, especificidad de 96%, y valores predictivos positivo y negativo de 95% y 88%, respectivamente. La correlación entre la nefelometría y el micraltest II TM fue 0.81 (p < 0.001). El mejor punto de corte para la detección de microAlbU fue 30.5 mg/L, y el área bajo la curva (± EE) fue 0.91 ± 0.03 (intervalo de confianza 95%: 0.85-0.96). En los pacientes no diabáticos con hipertensión esencial, el micraltest II TM tuvo una sensibilidad de 75%, especificidad de 95%, y valores predictivos positivo y negativo de 43 y 99%, respectivamente. La correlación entre los resultados de nefelometría y micraltest II TM fue 0.43 (p < 0.001). El mejor punto de corte para microAlbU fue 28.2 mg/L, y el área bajo la curva fue 0.85 ± 0.13 (intervalo de confianza 95%:0.60-1.10). Conclusión. La tira reactiva micraltest II TM es un método rápido, válido y confiable para el tamizaje de albuminuria en pacientes con diabetes mellitus tipo 2 y pacientes no diabáticos con hipertensión arterial esencial en nuestro medio.


Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Albuminuria/orina , /orina , Hipertensión/orina , Tamizaje Masivo/métodos , Tiras Reactivas , Albuminuria/etiología , Estudios Transversales , /complicaciones , Hipertensión/complicaciones , Microquímica , Nefelometría y Turbidimetría , Valor Predictivo de las Pruebas , Muestreo , Sensibilidad y Especificidad
8.
Braz. j. med. biol. res ; 38(4): 603-613, Apr. 2005. ilus, graf
Artículo en Inglés | LILACS | ID: lil-398182

RESUMEN

The influence of melatonin on the developmental pattern of functional nicotinic acetylcholine receptors was investigated in embryonic 8-day-old chick retinal cells in culture. The functional response to acetylcholine was measured in cultured retina cells by microphysiometry. The maximal functional response to acetylcholine increased 2.7 times between the 4th and 5th day in vitro (DIV4, DIV5), while the Bmax value for [125I]-alpha-bungarotoxin was reduced. Despite the presence of alpha8-like immunoreactivity at DIV4, functional responses mediated by alpha-bungarotoxin-sensitive nicotinic acetylcholine receptors were observed only at DIV5. Mecamylamine (100 µM) was essentially without effect at DIV4 and DIV5, while dihydro-ß-erythroidine (10-100 µM) blocked the response to acetylcholine (3.0 nM-2.0 µM) only at DIV4, with no effect at DIV5. Inhibition of melatonin receptors with the antagonist luzindole, or melatonin synthesis by stimulation of D4 dopamine receptors blocked the appearance of the alpha-bungarotoxin-sensitive response at DIV5. Therefore, alpha-bungarotoxin-sensitive receptors were expressed in retinal cells as early as at DIV4, but they reacted to acetylcholine only after DIV5. The development of an alpha-bungarotoxin-sensitive response is dependent on the production of melatonin by the retinal culture. Melatonin, which is produced in a tonic manner by this culture, and is a key hormone in the temporal organization of vertebrates, also potentiates responses mediated by alpha-bungarotoxin-sensitive receptors in rat vas deferens and cerebellum. This common pattern of action on different cell models that express alpha-bungarotoxin-sensitive receptors probably reflects a more general mechanism of regulation of these receptors.


Asunto(s)
Animales , Embrión de Pollo , Melatonina/farmacología , Receptores Nicotínicos/biosíntesis , Retina/metabolismo , Bungarotoxinas/metabolismo , Bungarotoxinas/farmacología , Células Cultivadas , Inmunohistoquímica , Microquímica , Antagonistas Nicotínicos/farmacología , Receptores Nicotínicos/efectos de los fármacos , Retina/citología , Retina/efectos de los fármacos , Factores de Tiempo , Triptaminas/farmacología
9.
Journal of Zhejiang University. Science. B ; (12): 69-73, 2005.
Artículo en Inglés | WPRIM | ID: wpr-316374

RESUMEN

Thermodynamic parameters of complexation of naphto-15-crown-5 with four alkaline earth ions in aqueous media was determined using titration microcalorimetry at 298.15 K. The stability of the complexes, thermal effect and entropy effect of the complexation is discussed on the basis of the guest ions structure and the solvent effect. The stability constants tendency to vary with ion radius was interpreted. Complex of naphtha-15-crown-5 with calcium ion is very stable due to the synergism of static electric interaction and size selectivity between the host and the guest.


Asunto(s)
Calorimetría , Métodos , Éteres Corona , Química , Iones , Química , Sustancias Macromoleculares , Química , Metales Alcalinotérreos , Química , Microquímica , Métodos
10.
Journal of Huazhong University of Science and Technology (Medical Sciences) ; (6): 25-27, 2004.
Artículo en Inglés | WPRIM | ID: wpr-330881

RESUMEN

A protocol for enrichment and adsorption of karyocyte from whole blood by using magnetic nanometer beads as solid-phase absorbents was presented. The PCR amplification could be accomplished by using the nanobeads with karyocyte as template directly and the PCR products were applied on an oligonucleotide array to do gene typing. The HLA-A PCR amplification system and a small HLA-A oligonucleotide microarray were applied as the platform and an experiment protocol of separating karyocyte from whole blood using the magnetic nanometer beads (Fe2O3) were set up. The experimental conditions were also discussed. It showed that pH level of PBS eluent, Taq enzyme quantity and fragment length of products could influent the amplification results, and the magnetic nano-beads could succeed in sample preparation in microarray to provide a promising way in automatic detection and lab-on-a-chip.


Asunto(s)
Adsorción , Separación Celular , Métodos , Genotipo , Leucocitos , Biología Celular , Magnetismo , Microquímica , Métodos , Nanotecnología , Análisis de Secuencia por Matrices de Oligonucleótidos , Métodos , Reacción en Cadena de la Polimerasa , Moldes Genéticos
11.
Acta Pharmaceutica Sinica ; (12): 64-67, 2004.
Artículo en Inglés | WPRIM | ID: wpr-301147

RESUMEN

<p><b>AIM</b>To establish a new and simple flow injection method for the rapid determination of acetylspiramycin (ASPM).</p><p><b>METHODS</b>ASPM was determined by chemiluminescence (CL) method combined with flow injection (FI) technology, which was based on the inhibitive effect of ASPM on the chemiluminescence reaction of the luminol-K3Fe (CN)6 system.</p><p><b>RESULTS</b>The decrease of chemiluminescence intensity was proportional to the logarithm of ASPM concentration (0.1-100) microgram.L-1, the detection limit was 40 ng.L-1 (3 sigma). The whole process, including sampling and washing, could be completed in 0.5 min with a RSD less than 3.0% (n = 5).</p><p><b>CONCLUSION</b>The FI-CL method is of both high sensitivity and good selectivity giving a throughput of 120 h-1. The proposed method was applied successfully to the determination of ASPM in pharmaceutical preparations and human urine without any pre-treatment. It was found that the ASPM concentration reached its maximum after being orally administrated for two hours.</p>


Asunto(s)
Humanos , Masculino , Antibacterianos , Sangre , Orina , Análisis de Inyección de Flujo , Mediciones Luminiscentes , Luminol , Química , Microquímica , Espiramicina , Sangre , Orina
12.
Journal of Biomedical Engineering ; (6): 316-320, 2004.
Artículo en Chino | WPRIM | ID: wpr-291122

RESUMEN

Piezoelectric quartz crystal biosensor is a new sensor developed with the comprehensive utilization of the high sensitivity to mass and the surface characteristics of quartz crystal such as density, viscosity, dielectric constant, conductance, and the high specificity of biologic identification molecules. It has the features of high sensitivity, high specificity, simple operation, high analysis speed, low cost, small size, on-line detection, etc. It can be of wide application in the areas of medical laboratory diagnosis, environment monitor, foods sanitary control and industrial production. In this paper, the fundamental principle, structure and its applications are reviewed.


Asunto(s)
Técnicas Biosensibles , Métodos , Cristalización , ADN Viral , Elasticidad , Electrodos , Diseño de Equipo , Métodos , VIH , Microquímica , Cuarzo
13.
Journal of Huazhong University of Science and Technology (Medical Sciences) ; (6): 25-7, 2004.
Artículo en Inglés | WPRIM | ID: wpr-634078

RESUMEN

A protocol for enrichment and adsorption of karyocyte from whole blood by using magnetic nanometer beads as solid-phase absorbents was presented. The PCR amplification could be accomplished by using the nanobeads with karyocyte as template directly and the PCR products were applied on an oligonucleotide array to do gene typing. The HLA-A PCR amplification system and a small HLA-A oligonucleotide microarray were applied as the platform and an experiment protocol of separating karyocyte from whole blood using the magnetic nanometer beads (Fe2O3) were set up. The experimental conditions were also discussed. It showed that pH level of PBS eluent, Taq enzyme quantity and fragment length of products could influent the amplification results, and the magnetic nano-beads could succeed in sample preparation in microarray to provide a promising way in automatic detection and lab-on-a-chip.


Asunto(s)
Adsorción , Separación Celular/instrumentación , Separación Celular/métodos , Genotipo , Leucocitos/citología , Magnetismo , Microquímica/instrumentación , Microquímica/métodos , Nanotecnología , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Reacción en Cadena de la Polimerasa , Moldes Genéticos
14.
An. acad. bras. ciênc ; 72(1): 5-25, mar. 2000.
Artículo en Inglés | LILACS | ID: lil-259473

RESUMEN

Supramolecular chemistry deals with the association of several chemical species, in an organized way and according to well defined purposes. Based on a molecular engineering approach, supramolecular structures can be designed from pre-formed building blocks, providing a promising route from chemistry to molecular nanotechnology. New supramolecular systems have been assembled in our laboratory with the use of bridging unities such as tetrapyridylporphyrins, porphyrazines and polypyrazines, connecting transition metal complexes and clusters. These systems display a very exciting electrochemical and catalytic behavior, and interact with DNA, generating 1O2 and leading to efficient oxidative clivage for photodynamic terapy applications. Molecular interfaces have been developed, exhibiting photocurrent response in the presence of visible-UV light, and rectifying properties in the presence of electroactive species. Successful applications of the supramolecular species in chemical and bio-sensors have been developed.


Asunto(s)
Metales/química , Microquímica , Técnicas Biosensibles , Compuestos Inorgánicos/química , Sustancias Macromoleculares , Estructura Molecular , Compuestos Organometálicos/química
15.
Indian J Biochem Biophys ; 1995 Oct; 32(5): 261-5
Artículo en Inglés | IMSEAR | ID: sea-28772

RESUMEN

The hydrolysis of p-nitrophenyl phosphate by the enzyme alkaline phosphatase has been studied in vegetable oil containing water-in-oil (W/O) microemulsions of six different compositions at four different (water)/(surfactant) mole ratios of 10, 17.6, 24.7 and 37. The vegetable oils used are ricebran oil (RO) and clove oil (CO) and the amphiphiles used are Aerosol OT (AOT), cinnamic alcohol (CA) and Tween-20 (T-20). The hydrolytic process does not follow conventional Michaelis Menten equation normally observed for enzymatic process. In the water/vegetable oil microemulsions, the enzyme seems to lose its activity when AOT is the amphiphile. The amount of p-nitrophenol generated as a result of hydrolysis is independent of the presence of the enzyme. With Tween-20 as the amphiphile, the microemulsion produces an initial retarding effect which ultimately gets appreciably compensated.


Asunto(s)
Fosfatasa Alcalina/análisis , Emulsiones , Microquímica , Aceites de Plantas/química , Agua/química
16.
Artículo en Inglés | IMSEAR | ID: sea-18064

RESUMEN

Used non-competitive enzyme-linked immunosorbent assay (ELISA) microplates were washed and reused to test samples and positive and negative controls, utilising the surplus reagents provided with the kit, which otherwise would have been discarded as useless after the entire 960 test kit had been utilized. These surplus reagents could be used for additional 220 tests over and above the recommended 960 tests per kit. A total of 839 unknown serum samples, 54 negative controls and 36 positive controls were tested using both washed and fresh (new) ELISA plates simultaneously. The optical density (OD) value of the control sera was within the prescribed limits in both the methods and 15 samples were found to be positive for HIV antibodies by the fresh plates whereas the washed plates showed 18 samples to be positive for HIV antibodies. None of the samples positive by fresh plates were negative by washed plates.


Asunto(s)
Control de Costos , Ensayo de Inmunoadsorción Enzimática/instrumentación , Equipo Reutilizado/economía , Femenino , Anticuerpos Anti-VIH/sangre , Humanos , Indicadores y Reactivos , Masculino , Microquímica
17.
Indian J Exp Biol ; 1984 Feb; 22(2): 91-3
Artículo en Inglés | IMSEAR | ID: sea-57633
19.
Hindustan Antibiot Bull ; 1978 Aug-Nov; 21(1-2): 11-6
Artículo en Inglés | IMSEAR | ID: sea-2466
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