Sete suínos com 2 meses de idade foram infectados experimentalmente com cerca de 200.000 ovos de T. solium administrados por via oral. Ao término do experimento (140 dias) os animais não apresentaram aspectos clínicos de cisticercose pelo exame de inspeção da língua; portanto eles poderiam ser classificados como animais saudáveis pelos exames usuais de inspeção utilizados em matadouros. Todos os animais foram sacrificados e a musculatura, cérebro e órgãos viscerais foram seccionados em finos pedaços para a procura de cistos. O número de cisticercos encontrados em cada animal variou de 1 a 85 (média 33,7 e desvio padrão 31,3), caracterizando-os como animais com infecção branda. Amostras de sangue dos animais infectados experimentalmente foram submetidas a imunoensaios para a pesquisa de anticorpos (ELISA Indireto, utilizando como antígeno o líquido vesicular de Taenia crassiceps; imunoblot 18/14, oriundo de antígeno de Taenia crassiceps purificado com anticorpos monoclonais e imunoblot LLGP, utilizando glicoproteínas de T. solium purificadas com lentil lectina) e para pesquisa de antígeno (ELISA Sanduíche e ELISA Direto, ambos utilizando o anticorpo monoclonal anti-ES-Tcra). O teste ELISA Direto não apresentou reatividade em qualquer amostra de soro dos diferentes animais infectados no momento do abate (t140). Foi encontrada positividade de 71% e 57%, respectivamente, para os testes ELISA Indireto para a pesquisa de anticorpos e ELISA Sanduíche para a pesquisa de antígenos nestes tempos. Pelo imunoblot (IB) 18/14 e IB LLGP, respectivamente 5 (71 %) e 6 (86%) dos animais infectados experimentalmente foram positivos no t140. O uso de ensaios imunoenzimáticos para a detecção de anticorpos específicos (IB) somados ao ELISA Sanduíche para pesquisa de antígeno permitiu que todos os animais com infecção branda fossem detectados. Dessa forma, o uso de ensaios imunoenzimáticos para detecção de anticorpos e/ou antígenos mostrou-se mais útil que o exame clínico e/ou post-mortem para a triagem de cisticercose suína em animais com infecção branda. / Seven 2-month-old swine were orally experimentally infected with approximately 200,000 eggs of Taenia solium. At the end of the experiment (140 days) the animals did not show clinical aspects of cysticercosis or parasites in tongue inspection; therefore they could be mistaken as healthy animals by usual inspection exams used in slaughterhouses. All of them were slaughtered and their whole muscles, brain and visceral organs were cut into thin slices searching for cysts. The number of cysts found in each animal varies from 1 to 85 (mean value 33.7 and standard deviation 31.3) characterizing them as slightly infected animals. Blood samples of experimentally infected animals were submitted to immunoassays for antibody detection (Indirect ELISA, using vesicular fluid antigen from Taenia crassiceps; immunoblot 18/14, from T.crassiceps antigen purified by monoclonal antibodies and immunoblot LLGP, using lentil lectin purified glycoproteins of T. solium) and for antigen detection (Sandwich ELISA and Direct ELISA, both using monoclonal antibodies anti-ES-Tcra). The Direct ELISA assay did not show any reactivity with all serum samples from the different animals at the slaughtered moment (t140). The positivity was 71% and 57% by the Indirect ELISA for searching antibodies and by the Sandwich ELISA for searching antigens, respectively. By immunoblot (IB) 18/14 and IB LLGP 5 (71 %) and 6 (86%) experimentally infected animals were positive at t140, respectively. The use of immunoassays for detecting specific antibodies (IB) together with Sandwich ELISA for antigen detection allow the detection of all slightly infected animals. Thus, the use of immunoassays for antibodies and/or antigen detection showed they are more useful than usual clinical examination and/or tongue palpation for screening cysticercosis in slightly infected pigs.

O Urso-de-óculos (Tremarctos ornatus), único urso endêmico da América do Sul, é uma espécie severamente ameaçada devido à perda do seu hábitat e à caça. É importante do ponto de vista da conservação pela função que cumpre no ecossistema onde habita e pela sua relação com a cultura Andina. Por estas razões, torna-se necessária a aplicação de alternativas de conservação a espécie. Uma ferramenta alternativa de conservação é a reprodução assistida, porém, existe pouco conhecimento da reprodução desta espécie. A pouca informação sobre os padrões reprodutivos diminui a possibilidade de se estabelecer programas de reprodução bem sucedidos e torna-se mais difícil a criação de planos de conservação. O objetivo deste estudo foi caracterizar o ciclo ovariano na fêmea do Urso-de-óculos. Para tanto foi realizada a monitoração endócrina por meio da extração e dosagem de metabólitos fecais dos esteróides sexuais: estradiol e progesterona. O estudo foi realizado com amostras colhidas de seis fêmeas de T. ornatus mantidas em cativeiro em dois zoológicos da cidade de Lima, Peru, pelo período de treze meses, desde Fevereiro de 2010 até Abril de 2011. As extrações dos metabólitos fecais foram feitas no Laboratorio de Reproducción Animal, FMVUNMSM, em Lima, Peru; e foram quantificados por enzimaimunoensaio (EIE), no Instituto de Bioquímica Médica, Veterinärmedizinische Universität Wien-Áustria. Os resultados indicam que é possível descrever e monitorar a endocrinologia do ciclo ovariano em T. ornatus de forma não-invasiva através do uso de metabólitos fecais de esteroides sexuais; demonstrando que o Urso-de-óculos em cativeiro é uma espécie que conta com uma reprodução não sazonal, com fase folicular e lútea durando em média 08 e 22 dias, respectivamente. Nestas condições, apresenta em média, de três a quatro fases de atividade ovarianas por ano. Os resultados encontrados ajudarão a compreender o ciclo ovariano nos Ursos-de-óculos e facilitar o desenvolvimento de programas de reprodução assistida na espécie. / Spectacled bear (Tremarctos ornatus) is the only bear species that inhabits South America. It is an endangered species due to habitat loss and hunting. For the conservation point of view it is an important species for the ecosystem maintenance and also for their relationship with the Andean culture. For these reasons it is necessary to apply conservation alternatives for this species. Assisted reproduction is an alternative conservation tool; however, there is a lack of knowledge of the Spectacled bear reproduction. Little information about the reproductive parameters diminishes the possibility to establish a successful breeding program and make difficult the implementation of conservation plans for the species. The aim of this study was to characterize the ovarian cycle in the female Spectacled bear with noninvasive techniques for monitoring fecal metabolites of reproductive hormones (estradiol and progesterone). The study was carried out with samples collected by a 13-month period (Feb/10 to April/11), from six captive females T. ornatus kept in two zoological institutions in Lima, Peru. The metabolites extraction was carried out at Laboratory of Animal Reproduction, FMV-UNMSM, in Lima-Peru, and the hormonal analysis was performed in the Institute of Medical Biochemistry, Veterinärmedizinische Universität Wien-Austria. The results show us that it is possible to describe and realize a non-invasive monitoring of ovarian cycles in T. ornatus, with the use of fecal metabolites of sex steroids; and demonstrates that in captive conditions Spectacled bear is a non-seasonal reproduction species, with follicular and luteal phases lasting on average 8 and 22 days, respectively, whereas in captivity has on average three to four stages of ovarian activity per year. These results will help to understand the ovarian cycle in Spectacled Bear and facilitate the development of programs of assisted reproduction in the species.

Law Wai Keung. / Thesis (M.Sc.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 98-108). / Abstracts in English and Chinese. / Abstract --- p.v / 摘要 --- p.viii / Acknowledgement --- p.x / List of Abbreviations --- p.i / Index of tables --- p.xiv / Index of figures --- p.xv / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Literature review --- p.3 / Chapter 2.1 --- Immunosuppression in Organ Transplantation --- p.3 / Chapter 2.2 --- Mechanism of Graft Rejection --- p.4 / Chapter 2.3 --- Conventional immunosuppressive drugs --- p.4 / Chapter 2.3.1 --- Corticosteriod --- p.6 / Chapter 2.3.2 --- Azathioprine --- p.6 / Chapter 2.3.3 --- Polyclonal antilymphocyte globulin and OKT3 --- p.7 / Chapter 2.4 --- Cyclosporine A (CsA) --- p.8 / Chapter 2.4.1 --- Mechanisms of CsA --- p.8 / Chapter 2.4.2 --- Pharmacokinetics of CsA --- p.10 / Chapter 2.4.2.1 --- Absorption --- p.10 / Chapter 2.4.2.2 --- Distribution --- p.11 / Chapter 2.4.2.3 --- Metabolism and elimination --- p.11 / Chapter 2.4.2.4 --- Toxicity --- p.12 / Chapter 2.4.3 --- Therapeutic drug monitoring of CsA --- p.13 / Chapter 2.4.3.1 --- CsA trough monitoring --- p.13 / Chapter 2.4.3.2 --- Full AUC monitoring --- p.15 / Chapter 2.4.3.3 --- Limited sampling strategy --- p.16 / Chapter 2.4.3.4 --- Two-hour post dose CsA level monitoring --- p.20 / Chapter 2.4.4 --- Conventional techniques of measuring cyclosporine concentration --- p.23 / Chapter 2.4.4.1 --- High performance liquid chromatography --- p.23 / Chapter 2.4.4.2 --- Non-specific immunoassays --- p.25 / Chapter 2.4.4.3 --- Specific radioimmunoassays --- p.26 / Chapter 2.4.4.4 --- Specific fluorescent polarization immunoassay --- p.26 / Chapter 2.4.4.5 --- Enzyme multiplied immunoassay technique --- p.28 / Chapter 2.4.4.6 --- Cloned enzyme donor immunoassay --- p.29 / Chapter 2.4.4.7 --- Summary for conventional techniques --- p.29 / Chapter 2.5 --- Liquid chromatography mass spectrometry for CsA measurement --- p.30 / Chapter 2.5.1 --- Main components of MS --- p.31 / Chapter 2.5.1.1 --- Specific interfaces to LC --- p.31 / Chapter 2.5.1.2 --- Mass analyzer --- p.33 / Chapter 2.5.1.3 --- Electron multiplier --- p.36 / Chapter 2.5.2 --- Sample preparation for LC-MS/MS for CsA measurement --- p.36 / Chapter 2.5.2.1 --- Liquid-liquid extraction --- p.37 / Chapter 2.5.2.2 --- Solid phase extraction --- p.38 / Chapter 2.5.2.3 --- Column switching --- p.39 / Chapter 2.5.2.4 --- Dilute and shoot --- p.40 / Chapter 2.5.3 --- LC-MS/MS for CsA measurement --- p.40 / Chapter 2.6 --- Summary --- p.42 / Chapter 3. --- Aim of study --- p.43 / Chapter 4. --- Materials and methods --- p.44 / Chapter 4.1 --- Materials --- p.44 / Chapter 4.1.1 --- Chemicals --- p.44 / Chapter 4.1.2 --- Equipment --- p.44 / Chapter 4.1.3 --- Reagent preparation for CsA analysis --- p.45 / Chapter 4.2 --- Methods --- p.48 / Chapter 4.2.1 --- Immunoassay --- p.48 / Chapter 4.2.2 --- Operation of tandem mass spectrometer --- p.48 / Chapter 4.2.2.1 --- Optimization of cone voltage --- p.50 / Chapter 4.2.2.2 --- Optimization of collision energy --- p.50 / Chapter 4.2.3 --- Optimization of LC-MS/MS --- p.51 / Chapter 4.2.3.1 --- Deproteinization procedures of whole blood --- p.52 / Chapter 4.2.3.2 --- Optimization of mobile phase flow rate --- p.52 / Chapter 4.2.3.3 --- Optimization of source temperature --- p.53 / Chapter 4.2.3.4 --- Optimization of the drying gas flow rate --- p.53 / Chapter 4.2.4 --- Matrix interference on MS/MS response --- p.53 / Chapter 4.2.5 --- Analytical performance of CsA on LC-MS/MS --- p.54 / Chapter 4.2.5.1 --- Linearity study --- p.54 / Chapter 4.2.5.2 --- Precision performance --- p.54 / Chapter 4.2.5.3 --- Accuracy performance --- p.54 / Chapter 4.2.5.4 --- The lowest detection limit of the CsA analysis --- p.55 / Chapter 4.2.5.5 --- Correlation study of the CsA analysis --- p.55 / Chapter 4.3 --- CsA pharmacokinetic studies in Chinese patients --- p.56 / Chapter 4.3.1 --- Determining the time point of CsA correlating better with AUC --- p.56 / Chapter 4.3.1.1 --- Patient and method --- p.56 / Chapter 4.3.1.2 --- Statistical analysis --- p.57 / Chapter 4.3.2 --- "Intra-individual variability of CO, C1 and C2" --- p.57 / Chapter 4.3.2.1 --- Patient and method --- p.57 / Chapter 4.3.2.2 --- Statistical analysis --- p.57 / Chapter 5. --- Results and discussion --- p.59 / Chapter 5.1 --- Optimization of MS parameters --- p.5 9 / Chapter 5.1.1 --- Optimization of cone voltage --- p.61 / Chapter 5.1.2 --- Optimization of collision energy --- p.63 / Chapter 5.2 --- Optimization of LC-MS/MS --- p.63 / Chapter 5.2.1 --- Optimization of mobile phase flow rate --- p.63 / Chapter 5.2.2 --- Optimization of ion source temperature and drying gas flow rate --- p.67 / Chapter 5.3 --- Matrix interference on MS/MS response --- p.69 / Chapter 5.4 --- Analytical performances of CsA on LC-MS/MS method --- p.71 / Chapter 5.4.1 --- Linearity --- p.71 / Chapter 5.4.2 --- Precision performance --- p.71 / Chapter 5.4.3 --- Accuracy performance --- p.72 / Chapter 5.4.4 --- The lowest limit of detection --- p.73 / Chapter 5.4.5 --- Correlation study of the CsA analysis --- p.80 / Chapter 5.5 --- The correlation between CsA at different point and AUCo-6 --- p.84 / Chapter 5.6 --- "Intra-individual variability of CO, C1 and C2" --- p.88 / Chapter 5.7 --- Therapeutic ranges of C2 --- p.90 / Chapter 5.8 --- Practical consideration for C2 measurement by LC-MS/MS method --- p.94 / Chapter 6. --- Conclusions --- p.97 / References --- p.98

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O objetivo deste estudo foi investigar na saliva de crianças pré-púberes obesas, em comparação com crianças eutróficas, a presença de possíveis diferenças na expressão de mediadores proteicos relacionados à metainflamação através de um estudo observacional transversal. Foram selecionadas 105 crianças pré-púberes com idade entre 5 e 9 anos, sem quaisquer outros comprometimentos sistêmicos ou bucais sendo realizada a mensuração do comprimento da circunferência da cintura (CC), além do peso e estatura para cálculo do IMC e seu escore Z (zscore IMC), de forma a compor 3 grupos: EU - eutrofia (-2SD&#8804; zscore IMC&#8804;1SD), SP - sobrepeso (1SD < zscore IMC < 2SD) e OB obesidade (zscore IMC &#8805; 2SD). Após o exame médico e odontológico foi feita a coleta de sangue e de saliva total não estimulada, de forma protocolada. Amostras séricas e salivares foram analisadas, individualmente, para a dosagem de IL1&#946;, IL6, IL8. IL10, IL12p70, TNF&#945;, MCP1, leptina, grelina e insulina, por Multiplex e adiponectina total e de alto peso molecular (adipoHMW), por ELISA. Além disso, as amostras séricas foram utilizadas para o delineamento hemodinâmico dos pacientes. As amostras salivares de EU e OB foram também analisadas em pools por espectrometria de massa (MS) e a presença de algumas proteínas foi validada por imunoblotting, para a comparação do perfil salivar proteico. As concentrações dos analitos foram comparadas tanto entre os grupos (teste de Kruswall-Wallis), como em relação ao zscore IMC e ao CC (Correlação de Spearman ou Pearson). Dos 12 analitos, somente a adipoHMW não foi detectada em nenhuma das amostras salivares. Na comparação OBxEU houve aumento na concentração total de proteínas salivares, da insulina e leptina sérica e salivar e do MCP1, além de diminuição da adiponectina sérica total e de adipoHMW e uma menor relação adiponectina/leptina (A/L) no grupo OB. As principais correlações obtidas com o zscore IMC foram com as concentrações séricas e salivares de insulina e leptina (positivas) e com a relação A/L (negativa), observando-se também a correlação negativa com a adiponectina total e adipoHMW séricas. Na comparação entre as concentrações séricas e salivares, foi possível detectar correlação positiva entre as dosagens de insulina e leptina, assim como com os valores da relação A/L. Na análise proteômica por MS foram identificadas 670 proteínas, sendo 163 delas com expressão diferenciada na saliva de OB em relação a EU. Dentre estas, encontram-se alteradas proteínas relacionadas à resposta inflamatória humoral, em especial com a via alternativa do sistema complemento e do metabolismo redox. Foram selecionadas três destas proteínas para validação por imunoblotting, que confirmou o aumento do Fator H e a diminuição do Fator B e da tioredoxina na saliva de OB em relação a EU. Considerando os resultados, podemos verificar que embora com menores concentrações absolutas dos mediadores, a saliva mostrou praticamente as mesmas associações observadas no sangue, em especial para a insulina, leptina e relação A/L, sendo possível admitir que a análise salivar venha a ser um bom método diagnóstico não invasivo para a obesidade infantil. / The aim of this study was to investigate possible different expressions of protein mediators related to metaflammation, in normal and obese prepubertal children`s saliva. For this cross-sectional observational study, 105 prepubertal children, between 5 and 9 years old, without oral or systemic disorders were selected. Weight, height and waist circumference (CC) were measured and body mass index (BMI) and BMI zscore were calculated in order to classify the children into the following groups: EU - lean (-2SD &#8804; BMI zscore &#8804; 1SD), SP - overweight (1SD < BMI zscore <2SD) and OB - obese (BMI zscore &#8805; 2SD). Following medical and dental examination, blood and unstimulated whole saliva were sampled. The samples were individually analyzed by immunoassay for IL1&#946;, IL6, IL8, IL10, IL12p70, TNF, MCP1, leptin, insulin and ghrelin, using Multiplex. Total and high molecular weight (adipoHMW) adiponectin were analyzed using ELISA. Additionally, serum samples were used to assess the patients lipid profile. Pools of EU and OB saliva samples were also analyzed by mass spectrometry (MS). The presence of some proteins was validated for by immunoblotting. The concentrations of analytes were compared between the groups EU, SP and OB (Kruswall-Wallis test), and in relation to BMI zscore and CC (Pearson or Spearman correlation). Only adipoHMW was not detected in any saliva sample. In comparison with EU, OB showed an increase in total concentration of salivary proteins, salivary and serum insulin, serum and salivary leptin and serum MCP1. Also, a decreased serum total adiponectin and adipoHMW and a lower A/L ratio were observed in the OB group. BMI zscore was positively correlated with insulin and leptin salivary and serum concentrations. A negative correlation with A/L ratio, serum total adiponectin and adipoHMW was also observed. These correlations were also found with CC. Comparing blood and saliva concentrations, significant associations between the dosages of insulin and leptin, as well as the values of A/L ratio were found. In proteomic analysis, by MS, 670 proteins were identified, and 163 of them with differential expression in saliva of OB in comparison to EU. Proteins related to the inflammatory response, in particular with the alternative pathway of the complement system and of redox metabolism were differently expressed between EU and OB. Three of these proteins were selected for validation by immunoblotting, which confirmed the increase of complement H Factor and reduced thioredoxin and complement B Factor expression in the saliva of OB compared to EU. Considering the results, it can be concluded that, although at lower absolute concentrations, the inflammatory mediators in saliva showed the same associations observed in blood, especially insulin, leptin, and A/L ratio. It is possible to assume that salivary analysis may become a useful noninvasive diagnosis method for childhood obesity.

Reducing cost and time is a major concern in clinical diagnostics. Current molecular diagnostics are multi-step processes that usually take at least several hours or even days to complete multiple reagents delivery, incubations and several washing processes. This highly labor-intensive work and lack of automation could result in reduced reliability and low efficiency. The Laboratory-on-a-chip (LOC), taking advantage of the merger and development of microfluidics and biosensor technology, has shown promise towards a solution for performing analytical tests in a self-contained and compact unit, enabling earlier and decentralized testing. However, challenges are to integrate the fluid regulatory elements on a single platform and to detect target analytes with high sensitivity and selectivity. The goal of this research work is to develop an AC electrokinetic (ACEK) flow through concentrator for in-situ concentration of biomolecules and develop a comprehensive understanding of effects of ACEK flow on the biomolecule transport (in-situ concentration) and their impact on electronic biosensing mechanism and performance, achieving automation and miniaturization. ACEK is a new and promising technique to manipulate micro/bio-fluids and particles. It has many advantages over other techniques for its low applied voltage, portability and compatibility for integration into lab-on-a-chip devices. Numerical study on preconcentration system design in this work has provided an optimization rule for various biosensor designs using ACEK technique. And the microfluidic immunoassay lab-chip designed based on ACET effect has showed promising prospect for accelerated diagnostics. With optimized design of channel geometry, electrode patterns, and properly selected operation condition (ac frequency and voltage), the preconcentration system greatly reduced the reaction time to several minutes instead of several hours, and improved sensitivity of the assay. With the design of immunoassay lab-chip, one can quantitatively study the effect of ACET micropumping and mixing on molecular level binding. Improved sensors with single-chip form factor as a general platform could have a significant impact on a wide-range of biochemical detection and disease diagnostics including pathogen/virus detection, whole blood analysis, immune-screening, gene expression, as well as home land security.

Many scientists and engineers are turning to lab-on-a-chip systems for cheaper and high throughput analysis of chemical reactions and biomolecular interactions. In this work, we developed several lab-on-a-chip modules based on novel manipulations of individual microbeads inside microchannels. The first manipulation method employs arrays of soft ferromagnetic patterns fabricated inside a microfluidic channel and subjected to an external rotating magnetic field. We demonstrated that the system can be used to assemble individual beads (1-3µm) from a flow of suspended beads into a regular array on the chip, hence improving the integrated electrochemical detection of biomolecules bound to the bead surface. In addition, the microbeads can follow the external magnet rotating at very high speeds and simultaneously orbit around individual soft magnets on the chip. We employed this manipulation mode for efficient sample mixing in continuous microflow. Furthermore, we discovered a simple but effective way of transporting the microbeads on-chip in the rotating field. Selective transport of microbeads with different size was also realized, providing a platform for effective sample separation on a chip. The second manipulation method integrates magnetic and dielectrophoretic manipulations of the same microbeads. The device combines tapered conducting wires and fingered electrodes to generate desirable magnetic and electric fields, respectively. By externally programming the magnetic attraction and dielectrophoretic repulsion forces, out-of-plane oscillation of the microbeads across the channel height was realized. Furthermore, we demonstrated the tweezing of microbeads in liquid with high spatial resolutions by fine-tuning the net force from magnetic attraction and dielectrophoretic repulsion of the beads. The high-resolution control of the out-of-plane motion of the microbeads has led to the invention of massively parallel biomolecular tweezers.

The teneurin C-terminal associated peptides (TCAP) are a family of four predicted peptides that are expressed in all metazoans where the teneurins have been studied to date. Of the four peptides, TCAP-1 has been studied most extensively. In vitro, TCAP-1 increases neuronal proliferation and neurite outgrowth. In vivo, the peptide reduces CRF-induced behavioural responses in rats. Despite the large body of evidence indicating a strong biological role for TCAP-1, little is known about the chemistry and solubility of the peptide, or the signaling pathway(s) mediating these effects. The aim of this research was to appropriately solubilize the peptide and to develop detection assays for its study in greater detail. I have now established an appropriate formulation of TCAP-1 and developed an immunoassay to assess its concentrations in tissues and in circulation. Also, by examining a number of transcriptional response elements, I have found two assays for probing the signal transduction mechanisms of this peptide.

The teneurin C-terminal associated peptides (TCAP) are a family of four predicted peptides that are expressed in all metazoans where the teneurins have been studied to date. Of the four peptides, TCAP-1 has been studied most extensively. In vitro, TCAP-1 increases neuronal proliferation and neurite outgrowth. In vivo, the peptide reduces CRF-induced behavioural responses in rats. Despite the large body of evidence indicating a strong biological role for TCAP-1, little is known about the chemistry and solubility of the peptide, or the signaling pathway(s) mediating these effects. The aim of this research was to appropriately solubilize the peptide and to develop detection assays for its study in greater detail. I have now established an appropriate formulation of TCAP-1 and developed an immunoassay to assess its concentrations in tissues and in circulation. Also, by examining a number of transcriptional response elements, I have found two assays for probing the signal transduction mechanisms of this peptide.

Determination of bio-material by using enzyme, fluorophore or metal-nanoparticles as markers is very important. Generally, gold-nanoparticles have been used frequently as marker for increasing the sensitivity in bio-chemical assay. In this research, gold-nanoparticles were used as marker for immunoassay, DNA sequence assay, and protein analysis. However, the size of gold-nanoparticles affects directly the results of electrochemical detection. For improving the sensitivity of electrochemical method, enlargement of gold-nanoparticles was used in this study. By electroless deposition, Au will be deposited on the surface of gold-nanoparticles. The electrochemical response will thus be increased substantially. In immunoassay and DNA sequence assay, traditional 96-wells microtiter plate was used for immobilizing antibody or oligonucleotide, and the gold-nanoparticles were marked subsequently base on the immunoreaction or protein reaction of streptavidin and biotin. After gold-nanoparticles were enlarged, they were dissolved and transferred to an electrochemical cell for square wave stripping voltammetry¡]SWSV¡^analysis. Under optimal experimental condition, dynamic range of 1 ~ 500 pg/mL and 0.52 ~ 1300 aM were found respectively for RIgG and Target DNA analysis, and a good linear relationship¡]R2 = 0.9975 and 0.9982¡^. The relative standard deviation¡]R.S.D.¡^ of blank were 2.8 % and 2.4 %¡]n = 11¡^for immunoassay and DNA assay, respectively. And the variance was 2.4 %¡]n = 9¡^and 2.4 %¡]n = 12¡^for immunoassay and DNA assay, respectively. The detection limit¡]based on S/N = 3¡^of RIgG and DNA were 0.25 pg/mL and 0.52 aM, respectively. They are very competitive compared with similar results reported in the literature. Additional, a gold nanoelectrode ensemble¡]GNEE¡^coupled microchip system was developed for bio-electrochemical analysis. Due to the difference in mobility of urea and urease were mixed and allowed the enzymatic reaction to proceed in microchannel. The enzymatic product NH4+ was determined by the coupled GNEE at the outlet of the channel. Another experiment of streptavidin conjugated gold-nanoparticles¡]streptavidin-Au¡^, reductant and gold-ion¡]Au3+¡^solution was be applied here, too. The product, NH4+ or Au3+ was passed through downstream of microchannel and detected by GNEE of electrochemical system. Satisfactory linear relationship¡]R2 = 0.9778 and 0.9657¡^were found from 0.1 mM to 50 mM for NH4+ and urea in the range of 0.02 mM to 5.0 mM, respectively. The other satisfactory linear relationship¡]R2 = 0.9842 and 0.9507¡^ were found between 3.75 mg/mL and 3.75 g/mL for Au3+ and streptavidin-Au in the range of 0.2 ng/mL to 100 ng/mL, respectively. Variances of 2.5 %¡]n = 6¡^was found for analysis of with the microchip system.

<p>Studies of binding reactions are of highest importance in a vast number of areas of biomedicine and biotechnology. A demand for fast and accurate small-volume measurements grows stronger, partly due to the development of therapeutic antibodies. In this report, a novel method for studies of binding reactions of antibodies is described. The use of a microfluidic platform shows promising results in determination of affinity binding constants.</p><p>Affinities between 1E-09 and 1E-11 M have been determined for four TSH antibodies. Reproducibility tests give a CV below 10%, using different Gyrolab instruments and microfluidic CD:s. The method carries the advantages of using solution-based measurements of unmodified molecules. Also an initial proof-of-concept for measurement of binding reaction rate constants shows further usage of the method. The kinetic association rate constant has been determined to 2E+06 M-1s-1 for one antibody. The possibility of using this method for screening of antibody libraries is also discussed.</p>