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Results for “multiplex imaging”

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At least 163 records · Page 9Linked to original sources

PubMed2003

Micromachining microcarrier-based biomolecular encoding for miniaturized and multiplexed immunoassay.

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.

Antigens↗

PubMed2004

Multiple-Locus Variable-Number Tandem-Repeats Analysis of Escherichia coli O157 using PCR multiplexing and multi-colored capillary electrophoresis.

The Multiple-Locus Variable-Number Tandem-Repeats Analysis (MLVA) method is currently being used as the primary typing tool for Shiga-toxin-producing Escherichia coli (STEC) O157 isolates in our laboratory. The initial assay was performed using a single fluorescent dye and the different patterns were assigned using a gel image. Here, we present a significantly improved assay using multiple dye colors and enhanced PCR multiplexing to increase speed, and ease the interpretation of the results. The different MLVA patterns are now based on allele sizes entered as character values, thus removing the uncertainties introduced when analyzing band patterns from the gel image. We additionally propose an easy numbering scheme for the identification of separate isolates that will facilitate exchange of typing data. Seventy-two human and animal strains of Shiga-toxin-producing E. coli O157 were used for the development of the improved MLVA assay. The method is based on capillary separation of multiplexed PCR products of VNTR loci in the E. coli O157 genome labeled with multiple fluorescent dyes. The different alleles at each locus were then assigned to allele numbers, which were used for strain comparison.

Animals↗

PubMed2006

Imaging of multiple mRNA targets using quantum dot based in situ hybridization and spectral deconvolution in clinical biopsies.

Gene expression mapping using microarray analysis has identified useful gene signatures for predicting outcome. However, little of this has been translated into clinically effective diagnostic tools as microarrays require high quality fresh-frozen tissue samples. We describe a methodology of multiplexed in situ hybridization (ISH) using a novel combination of quantum dot (QD)-labeled oligonucleotide probes and spectral imaging analysis in routinely processed, formalin-fixed paraffin embedded human biopsies. The conditions for QD-ISH were optimized using a poly d(T) oligonucleotide in decalcified bone marrow samples. Single and multiplex QD-ISH was performed in samples with acute leukemia and follicular lymphoma using oligonucleotide probes for myeloperoxidase, bcl-2, survivin, and XIAP. Spectral imaging was used for post hybridization tissue analysis, enabling separation of spatially colocalized signals. The method allows quantitative characterization of multiple gene expression using non-bleaching fluorochromes. This is expected to facilitate multiplex in situ transcript detection in routinely processed human clinical tissue.

Biopsy↗

PubMed2006

Cytometry on a chip: cellular phenotypic and functional analysis using grating-coupled surface plasmon resonance.

Grating-coupled surface plasmon resonance imaging (GCSPRI) is a method for the accurate assessment of both cell phenotype and function. In GCSPRI, cells and/or proteins of interest are flowed across antibodies immobilized on a gold-coated sensor chip. The surface of the chip is illuminated with monochromatic light that couples with surface plasmons in the gold. At a specific angle of incidence, the GCSPR angle, the maximum amount of coupling occurs. Shifts in the GCSPR angle can be correlated with refractive index changes following cell or analyte capture by the immobilized antibodies. In addition, GCSPRI can image the cells as they are being captured. GCSPRI's multiplexed format allows for the parallel assessment of up to 400 individual antibody regions. In this paper, we demonstrate GCSPRI's ability to identify cells and proteins of interest and compare results to a traditional flow cytometry system. This technology represents a fast and powerful method for the simultaneous assessment of cell phenotype and function.

Animals↗

PubMed2005

Peptides in body fluids and tissues as markers of disease.

The general awareness of the importance of peptides in physiology and pathophysiology has increased strongly over the last few years. With worldwide progress in the analysis of whole genomes, the knowledge base in gene sequence and expression data useful for protein and peptide analysis has drastically increased. The medical need for relevant biomarkers is enormous. This is particularly true for the many types of cancer, but other diseases such as Type 2 diabetes also lack useful and adequate diagnostic markers with high specificity and sensitivity. Despite advances in imaging technologies for early detection of diseases, proteomic and peptidomic multiplex techniques have evolved in recent years. This review focuses on the application of peptidomics technologies to peptides in health and disease. Peptidomics technologies provide new opportunities for the detection of low-molecular-weight proteome biomarkers (peptides) by mass spectrometry. Improvements in peptidomics research are based on separation of peptides and/or proteins by their physicochemical properties in combination with mass spectrometric detection, identification and sophisticated bioinformatics tools for data analysis. Therefore, peptidomics technologies offer an opportunity to discover novel biomarkers for diagnosis and management of disease (e.g., prognosis, treatment decision and monitoring response to therapy).

Animals↗

PubMed1994

Enzyme-linked fluorescent detection for automated multiplex DNA sequencing.

Initiatives to sequence DNA on a large scale have created a need for increased throughput and decreased costs. One scheme for increasing throughput, multiplex sequencing, involves the processing of a mixture of sequencing templates followed by sequential hybridization to reveal the individual sequence ladders on a membrane. Because multiplex sequencing has not been fully automated, and has not seemed automatable, few sequencing efforts have attempted to exploit it. We describe here a scheme for the automation of multiplex sequencing. Probe hybridized to target DNA is detected via spatially localized enzyme-linked fluorescence. Light output is high enough that imaging is possible with simple instrumentation. Direct imaging within an automated hybridization apparatus is made feasible so that the entire process will be automatic once a multiplex membrane is produced. The technique has the potential to increase severalfold the throughput of automated sequencing instruments required for sequencing the human genome.

Base Sequence↗

PubMed2004

Multiple-locus variable-number tandem-repeats analysis of Salmonella enterica subsp. enterica serovar Typhimurium using PCR multiplexing and multicolor capillary electrophoresis.

The multiple-locus variable-number tandem-repeats analysis (MLVA) method is currently being used as the primary typing tool for Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) isolates in our laboratory. Our published initial MLVA was performed using a single fluorescent dye and the different patterns were assigned from gel images. Here we present a new and significantly improved assay using multiple dye colors, enhanced PCR multiplexing and the introduction of two new loci for better adaptation to capillary electrophoresis with increased speed. The different MLVA patterns are now based on allele sizes entered as character values, thus removing the uncertainties introduced when analyzing band patterns from gel images. We additionally propose an easy numbering scheme for the identification of separate isolates that will facilitate exchange of typing data. A total of 106 human, bird, animal and food isolates of S. Typhimurium, including 16 with definite type (DT) 104, were used for the development of the improved MLVA. The method is based on capillary separation of multiplexed PCR products from five VNTR loci in the S. Typhimurium genome labeled with multiple fluorescent dyes. The different alleles at each locus were then assigned allele numbers, which were used for strain comparison.

Alleles↗

PubMed2006

Multiplex neuritis in a patient with autoimmune hepatitis: a case report.

A 37-year old woman presented with a 9-year history of hepatitis of unknown origin and aminotransferases within a 3-fold upper limit of normal. Autoimmune hepatitis (AIH) was diagnosed on the basis of elevated aminotransferases, soluble liver antigen/liver pancreas (SLA/LP) autoantibodies and characteristic histology. Immunosuppressive therapy led to rapid normalization of aminotransferases. Two years later, the patient developed left sided hemisensory deficits under maintenance therapy of prednisolone and azathioprine (AZT). Later she developed right foot drop and paraesthesia in the ulnar innervation territory on both sides. Magnetic resonance imaging (MRI) and cerebral panangiography suggested cerebral vasculitis. Neurological investigation and electromyography disclosed multiplex neuritis (MN) probably due to vasculitis. Consistent with this diagnosis, autoantibodies to extractable nuclear antigens were detectable in serum. Immunosuppression was changed to oral 150 mg cyclophosphamide (CPM0) per day. Prednisolone was increased to 40 mg/d and then gradually tapered to 5 mg. Oral CPM was administered up to a total dose of 40 g and then substituted by 6 times of an intervall infusion therapy of CPM (600 mg/m(2)). Almost complete motoric remission was achieved after 3 mo of CPM. Sensibility remained reduced in the right peroneal innervation territory. Follow-up of cranial MRI provided stable findings without any new or progressive lesions. This is the first report of multiplex neuritis in a patient with autoimmune hepatitis.

Adult↗

PubMed2000

A liquid core waveguide fluorescence detector for multicapillary electrophoresis applied to DNA sequencing in a 91-capillary array.

A new laser-induced fluorescence (LIF) detector for multicapillary electrophoresis is presented. The detection principle is based on waveguiding of the emitted fluorescence from the point of illumination to the capillary ends by total internal reflection (TIR) and imaging of the capillary ends. The capillaries themselves thus act as liquid core waveguides (LCWs). At the illumination point, the capillaries are arranged in a planar array, which allows clean and efficient illumination with a line-focused laser beam. The capillary ends are rearranged into a small, densely packed two-dimensional array, which is imaged end-on with high light collection efficiency and excellent image quality. Wavelength dispersion is obtained with a single prism. Intercapillary optical crosstalk is less than 0.5%, and rejection of stray light is very efficient. The detector is applied to four-color DNA sequencing by gel electrophoresis in a 91-capillary array, with simple fluorescein and rhodamine dyes as fluorophores. Since the imaged two-dimensional array is so compact, the detector has a high potential for very large-scale multiplexing.

Base Sequence↗

PubMed2005

Comparison of relative signal-to-noise ratios of different classes of imaging spectrometer.

The continued development of new and fundamentally different classes of imaging spectrometer has increased both the scope and the complexity of comparisons of their relative signal-to-noise ratios. Although the throughput and multiplex advantages of Fourier-transform spectrometers were established in the early 1950s, the application of this terminology to imaging spectrometers is often ambiguous and has led to some confusion and debate. For comparisons of signal-collection abilities to be useful to a system designer, they must be based on identical requirements and constraints. We present unambiguous definitions of terminology for application to imaging spectrometers and comparisons of signal-collection abilities and signal-to-noise-ratios on a basis that is useful to a systems designer and inclusive of six fundamentally different classes (both traditional and novel) of imaging spectrometers.

Journal Article↗

PubMed1999

Dynamic holographic imaging of the beating human heart

Background--Currently, the reporting and archiving of echocardiographic data suffer from the difficulty of representing heart motion on printable 2-dimensional (2D) media. Methods and Results--We studied the capability of holography to integrate motion into 2D echocardiographic prints. Images of normal human hearts and of a variety of mitral valve function abnormalities (mitral valve prolapse, systolic anterior motion of the mitral leaflets, and obstruction of the mitral valve by a myxoma) were acquired digitally on standard echocardiographic machines. Images were processed into a data format suitable for holographic printing. Angularly multiplexed holograms were then printed on a prototype holographic "laser" printer, with integration of time in vertical parallax, so that heart motion became visible when the hologram was tilted up and down. The resulting holograms displayed the anatomy with the same resolution as the original acquisition and allowed detailed study of valve motion with side-by-side comparison of normal and abnormal findings. Comparison of standard echocardiographic measurements in original echo frames and corresponding hologram views showed an excellent correlation of both methods (P<0.0001, r2=0.979, mean bias=2.76 mm). In this feasibility study, both 2D and 3D holographic images were produced. The equipment needed to view these holograms consists of only a simple point-light source. Conclusions--Holographic representation of myocardial and valve motion from echocardiographic data is feasible and allows the printing on a 2D medium of the complete heart cycle. Combined with the recent development of online holographic printing, this novel technique has the potential to improve reporting, visualization, and archiving of echocardiographic imaging.

Journal Article↗

PubMed2003

Feature-specific imaging.

We analyze the performance of feature-specific imaging systems. We study incoherent optical systems that directly measure linear projects of the optical irradiance distribution. Direct feature measurement exploit, the multiplex advantage, and for small numbers of projections can provide higher feature-fidelity than those systems that postprocess a conventional image. We examine feature-specific imaging using Wavelet, Karhunen-Loeve (KL), Hadamard, and independent-component features, quantifying feature fidelity in Gaussian-, shot-, and quantization-noise environments. An example of feature-specific imaging based on KL projections is analyzed and demonstrates that within a high-noise environment it is possible to improve image fidelity via direct feature measurement. A candidate optical system is presented and a preliminary implementational study is undertaken.

Journal Article↗

PubMed2006

Expanding the realm of fiber optic confocal sensing for probing position, displacement, and velocity.

We describe a fiber optic confocal sensor (FOCOS) system that uses an optical fiber and a lens to accurately detect the position of an object at, or close to, the image plane of the fiber tip. The fiber characteristics (diameter and numerical aperture) and optics (lens F/# and magnification) define the span and precision of the sensor and may be chosen to fit a desired application of position and displacement sensing. Multiple measurement points (i.e., fiber-tip images) may be achieved by use of multiple wavelengths in the fiber, so that each wavelength images the fiber at a different plane due to the chromatic dispersion of the optics. Further multiplexing may be achieved by adding fibers on the optical axis. A FOCOS with multiplexed fibers and wavelengths may also be used for velocity measurements.

Equipment Design↗

PubMed2005

Experimental realization of an imaging system with an extended depth of field.

We describe the experimental realization of an all-optical imaging system with an extended depth of field (DOF). The core of the system is a phase mask consisting of 16 Fresnel lenses (FLs) that are spatially multiplexed and mutually exclusive. Because each FL, in tandem with the primary lens, is designed to produce a sharp image for a specific object plane location, jointly the FLs achieve a wide DOF. However, the resultant image exhibits reduced resolution. The acquired image, onto which we did not apply any postprocessing, clearly is sharper than that acquired with a clear-aperture imaging system with the same pupil size.

Journal Article↗

PubMed2001

MR brain imaging of fucosidosis type I.

SUMMARY: Fucosidosis is a rare autosomal recessive lysosomal storage disease with the main clinical findings of progressive neuromotor deterioration, seizures, coarse facial features, dysostosis multiplex, angiokeratoma corporis diffusum, visceromegaly, recurrent respiratory infections, and growth retardation. Fucosidosis type I rapidly evolves toward a progressive neurologic deterioration and death. We report MR imaging findings of the brain of three patients with fucosidosis type I, including previously unreported findings, to expand the knowledge of the neuroradiologic spectrum of the disease.

Atrophy↗

PubMed1989

[Scintigraphy of the adrenergic nervous system].

The authors describe their experiences with 100 MIBG scintigraphies. The importance of the examination is stressed in the diagnostics of neuroblastoma in childhood, the determination of the clinical stage and follow-up of the disease. MIBG scintigraphy plays a primary role among the imaging examination procedures aimed at the localization of pheochromocytoma especially in the extra-adrenal, multiplex and malignant diseases. The disturbance of adrenergic innervation in Shy-Drager syndrome is demonstrable with radiopharmacon.

Adolescent↗

PubMed2006

Performance scaling in flat imagers.

A performance scaling formulation for flat form-factor cameras is introduced. The analysis follows from basic geometric and sensitivity constraints found in low-profile imaging sensors. A capacity metric is proposed and used to estimate performance cost scaling as a function of the width-to-height aspect ratio in the optics of thin imagers. Two basic flat imaging sensor classes are considered-one folds the optical path of an annular telescope within the volume of a central obscuration, and the other uses spatial multiplexing and filtering across an array of low-resolution small cameras to generate an estimate of the high-resolution image. Scaling trends are highlighted that enable general performance comparisons at the optical signal collection level, thereby providing conclusions that are independent of the computational aspects of any particular approach. The results indicate that thin imagers face significant costs in physical size and sampling requirements if they are to match the performance of conventional cameras in the basic parameters of field of view, resolution, dynamic range, and sensitivity.

Journal Article↗

PubMed1996

Evolution of the neuroimaging changes in fucosidosis type II.

We report on clinical and neuroradiological findings in two patients with fucosidosis type II; a 7-year-old Jordanian boy and a 3 1/2-year-old Anglo-Canadian girl. This rare, autosomal recessive disorder is caused by deficiency of lysosomal alpha-fucosidase and is manifested clinically by progressive mental and motor deterioration, coarse facies, growth retardation, recurrent infections, dysostosis multiplex, angiokeratoma corporis diffusum, visceromegaly and seizures. Cranial CT and magnetic resonance imaging showed density and signal abnormalities in the thalamus, globus pallidus and internal capsules bilaterally, as well as progressive CT density alterations in supratentorial white matter including the internal medullary laminae of the thalami and the internal capsules.

Brain↗