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1.
Vaccines (Basel) ; 12(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38543919

RESUMO

Yearly national immunization coverage reporting does not measure performance at the subnational level throughout the year and conceals inequalities within countries. We analyzed subnational immunization coverage from seven high-priority countries in our region. We analyzed subnational, monthly immunization data from seven high-priority countries. Five were Gavi eligible (i.e., Afghanistan, Pakistan, Somalia, Syria, and Yemen); these are countries that according to their low income are eligible for support from the Global Alliance on Vaccine and Immunization, while Iraq and Jordan were included because of a recent decrease in immunization coverage and contribution to the regional number of under and unimmunized children. DTP3 coverage, which is considered as the main indicator for the routine immunization coverage as the essential component of the immunization program performance, varied monthly in 2019-2021 before reaching pre-pandemic coverage in the last two months of 2021. Somalia and Yemen had a net gain in DTP3 coverage at the end of 2021, as improvement in 2021 exceeded the regression in 2020. In Pakistan and Iraq, DTP3 improvement in 2021 equaled the 2020 regression. In Afghanistan, Syria and Jordan, the regression in DTP3 coverage continued in 2020 and 2021. The number of districts with at least 6000 zero-dose children improved moderately in Afghanistan and substantially in Somalia throughout the follow-up period. In Pakistan, the geographical distribution differed between 2020 and 2021.Of the three countries with the highest number of zero-dose children, DTP1 coverage reached 109% in Q4 of 2020 after a sharp drop to 69% in Q2 of 2020. However, in Pakistan, the number of zero-dose children decreased to 1/10 of its burden in Q4 of 2021. In Afghanistan, the number of zero-dose children more than a doubled. Among the even countries, adaptation of immunization service to the pandemic varied, depending on the agility of the health system and the performance of the components of the expanded program on immunization. We recommended monitoring administrative monthly immunization coverage data at the subnational level to detect low-performing districts, plan catchup, identify bottlenecks towards reaching unvaccinated children and customize strategies to improve the coverage in districts with zero-dose children throughout the year and monitor progress.

2.
Vaccines (Basel) ; 12(3)2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38543948

RESUMO

Somalia is a complex and fragile setting with a demonstrated potential for disruptive, high-burden measles outbreaks. In response, since 2018, Somalian authorities have partnered with UNICEF and the WHO to implement measles vaccination campaigns across the country. In this paper, we create a Somalia-specific model of measles transmission based on a comprehensive epidemiological dataset including case-based surveillance, vaccine registries, and serological surveys. We use this model to assess the impact of these campaign interventions on Somalian's measles susceptibility, showing, for example, that across the roughly 10 million doses delivered, 1 of every 5 immunized a susceptible child. Finally, we use the model to explore a counter-factual epidemiology without the 2019-2020 campaigns, and we estimate that those interventions prevented over 10,000 deaths.

3.
Vaccine ; 42(9): 2239-2245, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38413276

RESUMO

National Immunization Technical Advisory Groups (NITAGs) are independent bodies that help improve national immunization programmes in decision making on immunization policy. The new NITAG Maturity Assessment Tool (NMAT) provided an opportunity to conduct a region-wide assessment to improve NITAG capacity and foster institutional growth. We share experience of the Eastern Mediterranean Region (EMR) of the World Health Organization (WHO) in using NMAT and the use of findings to develop improvement plans. NITAG chairs and secretariats from 22 EMR countries attended a virtual NMAT training in 2023. They self-assessed their NITAGs using the tool and developed improvement plans. An algorithm used the data to determine maturity levels for seven indicators. We consolidated results for the region by income groups. Of 22 countries (or NITAGs), 20 (91%) submitted NITAG assessment findings and 19 an improvement plan. The proportion of criteria met per indicator varied from 36% for independence and non-bias to 74% for establishment and composition. Maturity level varied by indicator. Of 20 NITAGs, less than half had an intermediate or higher-level maturity for the indicators of independence and non-bias 1 (5%), operations 3 (15%), making recommendations 4 (20%), stakeholder recognition 6 (30%), and resources and secretariat support 7 (35%). Meanwhile 11 (55%) NITAGs had an intermediate or higher maturity level for the indicators of establishment and composition and for integration into policy making process. Participants described NMAT as a concise, useful, user-friendly tool. NMAT is a practical tool that can be used by NITAGs to provide insights and strategic direction for individual countries and regionally. Prevention and management of conflict of interest is the domain that requires the most improvement in EMR. Planned activities should be implemented, monitored and a follow up assessment conducted in 2025.


Assuntos
Comitês Consultivos , Política de Saúde , Humanos , Programas de Imunização , Imunização , Organização Mundial da Saúde
4.
East Mediterr Health J ; 29(9): 681-683, 2023 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-37776128

RESUMO

Every year, WHO and UNICEF estimate the immunization coverage for 195 Member States, based on reported data and independent coverage surveys (1,2). These estimates indicate progress in reaching children with life-saving vaccines while identifying coverage gaps (3). The 2022 estimates were much awaited, given that the COVID-19 pandemic caused a setback in coverage (1). Overall, there are encouraging signs of recovery in the WHO Eastern Mediterranean Region (EMR). For example, coverage of the third dose diphtheria-pertussis-tetanus containing vaccine (DTPcv3) and the second dose measles containing vaccine (MCV2), both almost restored or exceeded their 85% and 76% pre-pandemic 2019 levels, respectively (1). However, there are disparities across countries. Low-income countries with fragile, weak health systems and those in conflict situation are lagging. The number of children who missed their routine first dose of measles immunization increased from 3 million in 2019 to 3.16 million in 2022 (1). This underperformance, along with the accumulated immunity gap in 2020-2021, exposes us to the risk of preventable deadly outbreaks.


Assuntos
COVID-19 , Sarampo , Criança , Humanos , Lactente , Pandemias/prevenção & controle , Programas de Imunização , COVID-19/epidemiologia , COVID-19/prevenção & controle , Imunização , Vacinação , Vacina contra Sarampo/uso terapêutico , Vacina contra Difteria, Tétano e Coqueluche , Região do Mediterrâneo/epidemiologia , Sarampo/epidemiologia , Sarampo/prevenção & controle , Esquemas de Imunização
5.
East Mediterr Health J ; 29(2): 87-88, 2023 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-36880488

RESUMO

Over the years, the Eastern Mediterranean Region (EMR) has faced a funding gap with respect to malaria, tuberculosis (TB), HIV, and vaccine-preventable diseases programmes. In the early 2000s, Gavi, the Vaccine Alliance (Gavi) and the Global Fund against AIDS, TB and Malaria (GFATM) became important financial contributors to these programmes. In 2000-2015, funding support from these two global health initiatives allowed progress. However, from 2015, coverage of interventions plateaued, and the region is now behind on the related Sustainable Development Goal (SDG) targets.


Assuntos
Doenças Transmissíveis , Humanos , Região do Mediterrâneo/epidemiologia
7.
Vaccine ; 39(15): 2146-2152, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33712350

RESUMO

Countries face an increasingly complex vaccination landscape. As well as ever-changing infectious disease epidemiology, the number and diversity of vaccine-preventable diseases, vaccine products, and vaccine technologies continue to increase. To ensure that vaccination decision-making is transparent, country-owned and informed by sound scientific evidence, many countries have established national immunization technical advisory groups (NITAGs) to provide independent expert advice. The past decade has seen substantial growth in NITAG numbers and functionality, and there is now a need to consolidate this progress, by further capacity building, to ensure that NITAGs are responsive to the changing face of immunization over the next decade.


Assuntos
Programas de Imunização , Vacinas , Comitês Consultivos , Política de Saúde , Vacinação
8.
MMWR Morb Mortal Wkly Rep ; 68(22): 505-510, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31170125

RESUMO

In 1997, the 21 countries in the World Health Organization (WHO) Eastern Mediterranean Region* (EMR) passed a resolution during the 41st session of the Regional Committee for the Eastern Mediterranean to eliminate measles† (1). In 2015, this goal was included as a priority in the Eastern Mediterranean Vaccine Action Plan 2016-2020 (2), approved at the 62nd session of the Regional Committee (3). To achieve measles elimination, the WHO Regional Office for the Eastern Mediterranean developed the following four-pronged strategy: 1) achieve ≥95% vaccination coverage with the first dose of measles-containing vaccine (MCV) among children in every district of each country through routine immunization services; 2) achieve ≥95% vaccination coverage with a second MCV dose in every district of each country either through implementation of a routine 2-dose vaccination schedule or through supplementary immunization activities (SIAs)§; 3) conduct high-quality, case-based measles surveillance in all countries; and 4) provide optimal measles clinical case management, including dietary supplementation with vitamin A (4). Pakistan, an EMR country with a population of approximately 200 million, accounts for nearly one third of the overall EMR population. This report describes progress and challenges toward measles elimination in Pakistan during 2000-2018. During the study period, estimated coverage with the first MCV dose (MCV1) increased from 57% in 2000 to 76% in 2017. The second MCV dose (MCV2) was introduced nationwide in 2009, and MCV2 coverage increased from 30% in 2009 to 45% in 2017. During 2000-2018, approximately 232.5 million children received doses of MCV during SIAs. Reported confirmed measles incidence increased from an average of 24.6 per 1 million persons during 2000-2009 to an average of 80.4 during 2010-2018, with peaks in 2013 (230.3) and 2018 (153.6). In 2017 and 2018, the rates of suspected cases discarded as nonmeasles after investigation were 2.1 and 1.5 per 100,000 population, reflecting underreporting of cases. To achieve measles elimination, additional efforts are needed to increase MCV1 and MCV2 coverage, develop strategies to identify and reach communities not accessing immunization services, and increase sensitivity of case-based measles surveillance in all districts.


Assuntos
Erradicação de Doenças , Sarampo/epidemiologia , Sarampo/prevenção & controle , Vigilância da População , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Programas de Imunização , Esquemas de Imunização , Lactente , Masculino , Vacina contra Sarampo/administração & dosagem , Paquistão/epidemiologia , Cobertura Vacinal/estatística & dados numéricos
9.
Proc Natl Acad Sci U S A ; 116(22): 11069-11073, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31085656

RESUMO

Measles remains a major contributor to preventable child mortality, and bridging gaps in measles immunity is a fundamental challenge to global health. In high-burden settings, mass vaccination campaigns are conducted to increase access to vaccine and address this issue. Ensuring that campaigns are optimally effective is a crucial step toward measles elimination; however, the relationship between campaign impact and disease dynamics is poorly understood. Here, we study measles in Pakistan, and we demonstrate that campaign timing can be tuned to optimally interact with local transmission seasonality and recent incidence history. We develop a mechanistic modeling approach to optimize timing in general high-burden settings, and we find that in Pakistan, hundreds of thousands of infections can be averted with no change in campaign cost.


Assuntos
Programas de Imunização , Vacina contra Sarampo/administração & dosagem , Sarampo/prevenção & controle , Criança , Pré-Escolar , Humanos , Lactente , Sarampo/epidemiologia , Sarampo/transmissão , Modelos Estatísticos , Paquistão/epidemiologia , Fatores de Tempo
10.
Drug Deliv ; 23(1): 130-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-24786489

RESUMO

The aim of the present study was to prepare and evaluate a rasagiline-loaded chitosan glutamate nanoparticles (RAS-CG-NPs) by ionic gelation of CG with tripolyphosphate anions (TPP). RAS-loaded CG-NPs were characterized for particle size, size distribution, encapsulation efficiency and in vitro drug release. The mean particles size, polydispersity index (PDI) and encapsulation efficiency was found to be 151.1 ± 10.31, 0.380 ± 0.01 and 96.43 ± 4.23, respectively. Biodistribution of RAS formulations in the brain and blood of mice following intranasal (i.n.) and intravenous (i.v.) administration was performed using HPLC analytical method. The drug concentrations in brain following the i.n. of CG-NPs were found to be significantly higher at all the time points compared to both drug (i.n.) and drug CG-NPs (i.v.). The Cmax (999.25 ng/ml) and AUC (2086.60 ng h/ml) of formulation CG-NPs (i.n) were found to be significantly higher than CG-NPs (i.v.) and RAS solution (i.n.). The direct transport percentage (DTP%) values of RAS-loaded CG-NPs (i.n.) as compared to drug solution (i.n.) increased from 66.27 ± 1.8 to 69.27 ± 2.1%. The results showed significant enhancement of bioavailability in brain, after administration of the RAS-loaded CG-NPs which could be a substantial achievement of direct nose to brain targeting in Parkinson's disease therapy.


Assuntos
Encéfalo/metabolismo , Indanos/farmacocinética , Fármacos Neuroprotetores/farmacocinética , Administração Intranasal , Animais , Disponibilidade Biológica , Química Farmacêutica , Quitosana/química , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Cabras , Indanos/administração & dosagem , Masculino , Camundongos , Nanopartículas , Mucosa Nasal/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Doença de Parkinson/tratamento farmacológico , Distribuição Tecidual
11.
J Ayub Med Coll Abbottabad ; 27(1): 220-2, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26182781

RESUMO

BACKGROUND: Pakistan is one of the remaining 24 countries which have not yet achieved Maternal and Neonatal Tetanus Elimination (MNTE), The country adopted high-risk approach for 56 out of 119 districts with country-wide Tetanus Toxoid (TT) provision in Routine Immunization (RI) during early 2000-2003. The TT's mass campaigns could only cover 13% of high risk districts for 2009- 2011, and mostly for the Punjab province. To achieve MNT elimination, the country needs risk mapping for cost-effective intervention. METHODS: We used both the quantitative and qualitative methods to conduct risk characterization. All the three available data sets (Reported EPI coverage data, PDHS 2012-13, and PSLM 2010-11) were assessed. A mix of core and surrogate indicators-for risk categorization was used through ranking and scoring the aggregated data and considering the past tetanus campaigns' coverage. Tetanus Toxoid (TT2+)-coverage of pregnant women and delivery in health facility, both received more weightage in scoring. We based the higher and lower cuts off points for each indicator on data ranges. The districts with higher scores, i.e., 10.5 and above were ranked good followed by medium (5.5-10.4) and low performing (less than 5.5). Consultations with the national and provincial field officers were utilized to understand the local context. RESULTS: In Pakistan, there are 139 districts out of which, 60 are the high risk districts for tetanus. Highest percentage is for Baluchistan (83%) followed by Sindh (52%), and Khyber Pakhtunkhwa (40%). Most of the Punjab is at medium risk (55%), followed by KP (52%), and Sindh (39%). CONCLUSION: Pakistan is at medium to high risk of MNT with a great variation at the sub-national level. Campaigns aiming to these districts may bring the country closer to MNT elimination target.


Assuntos
Complicações Infecciosas na Gravidez/prevenção & controle , Medição de Risco , Tétano/prevenção & controle , Vacinação , Adulto , Feminino , Humanos , Incidência , Recém-Nascido , Masculino , Paquistão/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Resultado da Gravidez , Estudos Retrospectivos , Tétano/epidemiologia
12.
Methods Mol Biol ; 300: 369-81, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15657492

RESUMO

This chapter describes the construction of addressable two-dimensional (2D) microarrays via the random fluidic self-assembly of metallic particles and the use of these arrays as platforms for constructing protein chips for bioassays. These arrays will be useful as platforms for constructing protein chips for bioassays in a broad range of applications. The basic units in the assembly are microfabricated particles, which carry a straightforward visible code, and the corresponding array template patterned on a glass substrate. On one face, the particles consist of a hydrophobic and magnetic Ni-polytetrafluoroethylene (Ni-PTFE) composite layer; the other face has a gold layer that was modified for biomolecular attachment. We use photoresist patterning to create an array template with spatially discrete microwells into which an Ni-PTFE hydrophobic composite layer and a hydrophobic photoadhesive coating are electrodeposited. After biomaterial attachment and binding processes in bulk, the particles are randomly self-assembled onto the lubricated bonding sites on the chip substrate. This self-assembly process is driven by a combination of magnetic, hydrophobic, and capillary interactions. The encoding symbol carried by each particle is used to identify the target attached to the particle surface. This model system demonstrates the utility of the protein chip array for conducting simultaneous multianalyte immunoassays of human immunoglobulins (IgA, IgG, and IgM).


Assuntos
Técnicas Biossensoriais/métodos , Nanotecnologia/métodos , Análise Serial de Proteínas/métodos , Animais , Humanos , Imunoensaio/métodos , Imunoglobulinas/análise , Medições Luminescentes/métodos
13.
J Biochem ; 136(2): 149-54, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15496584

RESUMO

The completion of human genome sequencing has shifted the focus of research from genes to proteins. In this regard, a protein library chip has become a useful tool for cell-free protein synthesis. In this study, we attempted to make a highly-integrated protein chip from a DNA library using in vitro protein synthesis on a microchamber array fabricated by using PDMS (polydimethyl siloxane), a hydrophobic surface, and glass, a hydrophilic bottom substrate. These structural properties prevented cross-contamination among the chambers. The minimum volume capacity of the smallest chamber was about 1 pl. The total number of chambers per chip was 10,000 on one chip (capacity 150 pl) and 250,000 on two others (1 and 5 pl). Next, we attempted in vitro protein synthesis using this microchamber array. The fluorescence of Green Fluorescent Protein (GFP) expressed on the chamber was rapidly detected (within just 1 h). GFP expression was also successful using immobilized DNA molecules on polymer beads. DNA immobilized beads were added as the source to each microchamber. Protein was successfully synthesized from DNA immobilized beads, which allowed easy handling of the DNA molecules.


Assuntos
Análise Serial de Proteínas/instrumentação , Análise Serial de Proteínas/métodos , Sistema Livre de Células , Imunoprecipitação da Cromatina , DNA/química , Dimetilpolisiloxanos/química , Biblioteca Gênica , Vidro/química , Proteínas de Fluorescência Verde/metabolismo , Humanos , Íons , Microscopia de Fluorescência , Oxigênio/metabolismo , Polímeros/química , Silicones/química , Fatores de Tempo
14.
Environ Toxicol Pharmacol ; 16(3): 141-5, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21782700

RESUMO

Effects of two widely found chemical pollutants, bis(2-ethylhexyl) phthalate (DEHP) and benzo[a]pyrene (BaP), on the embryos of Japanese medaka were investigated. The embryos were exposed to different concentrations (0.01, 0.1, 1, and 10µg/l) of DEHP and BaP. The following were investigated: (1) hatching time and hatching rate in embryos, (2) mortality, sex ratio, body weight and gonadosomatic index (GSI) in adulthood. These two chemicals delayed the hatching time without dose-dependence, but these chemicals had no effect on hatching rate. Mortality was raised and body weight was reduced by DEHP and BaP-treatment; distortion of sex ratio appeared at the lowest concentration of DEHP tested. GSI was decreased because of the BaP-treatment. DEHP and BaP negatively affected Japanease medaka embryos, and the influences of the effects continued into adult stage. Moreover, the effects did not appear to be necessarily dose-dependent.

15.
Environ Toxicol Pharmacol ; 17(1): 29-33, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-21782710

RESUMO

The effects of oral administration of tamoxifen, 17α-ethynylestradiol (EE2), flutamide, and methyltestosterone (MT), on plasma vitellogenin levels of male and female medaka were investigated. Medaka were fed diets containing different concentrations of these chemicals for 7 days, and these plasma vitellogenin levels were measured. Tamoxifen increased significantly the vitellogenin levels in male, but inhibited the normal vitellogenin induction in female in the high concentration groups. EE2 increased significantly vitellogenin levels in both sexes. Flutamide increased significantly the vitellogenin levels in female, but gave no effects on male. MT inhibited the normal vitellogenin induction in female, but increased slightly vitellogenin levels in male without a clear tendency. Administration of tamoxifen, EE2, flutamide, and MT showed the different pattern in vitellogenin levels in both sexes.

16.
Environ Toxicol Pharmacol ; 18(1): 9-12, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21782730

RESUMO

The effects of bis(2-ethylhexyl) phthalate (DEHP), γ-hexachlorocyclohexane (γ-HCH), and 17ß-estradiol (E2) on the fry stage of medaka were investigated. The medaka fry were exposed to different concentrations (0.01, 0.1, 1, and 10µg/L) of these chemicals for 3 weeks after hatching. Then, mortality, body weight, sex ratio, and gonadosomatic index (GSI) of the matured fish (after 5 months) were measured. Mortality was increased significantly in the 10µg/L E2 group. Distortion of sex ratio was found in 1 and 10µg/L E2 groups. DEHP treated groups showed the GSI reduction only in male fish. All the γ-HCH and parts of the E2 treated groups showed the GSI reduction in both sexes. Exposure of DEHP, γ-HCH, and E2 during the fry stage affected normal maturation of medaka at the concentrations which had no impact on mortality or sex ratio.

17.
Anal Chem ; 75(16): 4125-31, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-14651038

RESUMO

Micromachining techniques, which originated in the microelectronics industry, have been employed to manufacture microparticles bearing an engraved dot-type signature for biomolecular encoding. These metallic microstructures are photolithographically defined and manufactured in a highly reproducible manner. In addition, the code introduced on the particle face is a straightforward visible feature that is easily recognizable with the use of optical microscopy. The number of distinct codes theoretically could be many thousands, depending on the coding element numbers. Such microparticles are, thus, with appropriate surface organic functionalizations, ideal for encoding biomolecular libraries and serving as a platform for developing high-throughput multiplexed bioassay schemes based on suspension array technology. As proof of this statement, we demonstrated that encoded microparticles tagged with antibodies to human immunoglobulin classes are capable, using imaging detection as the interrogating approach, of high sensitivity and high specificity, as well as multiplexed detection of the respective antigens in a microliter-sample volume.


Assuntos
Antígenos/análise , Imunoensaio/métodos , Miniaturização/métodos , Fluorocarbonos/farmacologia , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Separação Imunomagnética , Medições Luminescentes , Microesferas , Nanotecnologia
18.
J Biochem ; 134(3): 353-8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14561720

RESUMO

This paper describes a method for imaging the endogenous release of glutamate from cerebral neurons. This method is based on the reactions of glutamate oxidase and peroxidase, and on the detection of hydrogen peroxide by a fluorescent substrate of peroxidase. Glutamate has been sensitively measured in vitro in the range of 20 nM to 1 microM. We used two types of Ca(2+) channel inhibitors, MK-801 and omega-Conotoxin GVIA, which act to suppress Ca(2+) transport at postsynaptic and presynaptic neurons, respectively. MK-801 did not inhibit the increase in glutamate release after KCl stimulation, while there was no increase in glutamate release after KCl stimulation when omega-Conotoxin GVIA was used, probably due to the inhibition of voltage-activated Ca(2+) channels in the presynapse. Glutamate release and Ca(2+) flow in the synaptic regions were imaged using a laser confocal fluorescence microscope. KCl-evoked glutamate release was localized around cell bodies linked to axon terminals. This procedure allows imaging that can be sensitively detected by the fluorometric enzymatic assay of endogenous glutamate release in synapses.


Assuntos
Encéfalo/citologia , Fluorometria , Ácido Glutâmico/análise , Microscopia Confocal/métodos , Neurônios/citologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio/metabolismo , Células Cultivadas , Embrião de Galinha , Ensaios Enzimáticos Clínicos , Neurônios/metabolismo , Peroxidase/metabolismo , Cloreto de Potássio/farmacologia , Fatores de Tempo
19.
Anal Biochem ; 318(2): 236-43, 2003 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-12814627

RESUMO

This paper describes the random fluidic self-assembly of metallic particles into addressable two-dimensional microarrays and the use of these arrays as a platform for constructing a biochip useful for bioassays. The basic units in the assembly were the microfabricated particles carrying a straightforward visible code and the corresponding array template patterned on a glass substrate. The particles consisted of a hydrophobic and magnetic Ni-polytetrafluoroethylene (PTFE) composite layer on one face, and on the other face a gold layer that was modified for biomolecular attachment. An array template was photoresist-patterned with spatially discrete microwells in which an electrodeposited Ni-PTFE hydrophobic composite layer and a hydrophobic photo-adhesive coating were deposited. The particles, after biomaterial attachment and binding processes in bulk, were self-assembled randomly onto the lubricated bonding sites on the chip substrate, driven by a combination of magnetic, hydrophobic, and capillary interactions. The encoding symbol carried by the particles was used as the signature for the identification of each target/assay attached to the particle surface. We demonstrate here the utility of microfabricated-encoded particle arrays for conducting multianalyte immunoassays in a parallel fashion with the use of imaging detection.


Assuntos
Biotecnologia/instrumentação , Biotecnologia/métodos , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Bioensaio/instrumentação , Bioensaio/métodos , Calibragem , Microfluídica
20.
Environ Toxicol Pharmacol ; 15(1): 33-6, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21782677

RESUMO

The effect that oral administration of four alkylphenols, (1) bisphenol A (BPA), (2) p-t-octylphenol (OP), (3) p-nonylphenol (NP) and (4) p-n-nonylphenol (n-NP), as well as 17α-ethynylestradiol (EE2) had on male medaka fish vitellogenin was investigated. The male medaka was fed diets containing different concentrations of these chemicals for 7 days, after which their plasma vitellogenin levels were measured. Vitellogenin levels up to ≈10(7) ng/ml were found. This value is close to that of the normal estrous female medaka. The median effective concentration (EC(50)) values resulting from BPA, OP, NP and EE2 in the diet were calculated as 1600, 2600, 940 and 0.37 µg/g diet, respectively.

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