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Results for “multiplex imaging”

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At least 307 records · Page 17Linked to original sources

PubMed1996

[Early diagnosis of optic nerve neuropathy in multiple sclerosis].

PURPOSE: To evaluate diagnostic sensitivity of clinical tests in optic demyelinating neuropathy. MATERIAL AND METHODS: We examined 21 persons (38 eyes) with confirmed sclerosis multiplex (SM) with no episodes of posterior optic neuritis in the history of the disease. The examination method included: Static perimetry of central visual field (30 degrees, by Octopus 101), pattern visual evoked potentials (p VEP), colour photographs of optic disc and magnetic resonance imaging (MR) of central nervous system, optic nerves and optic chiasm. Visual acuity and colour vision were normal. RESULTS: There was statistically significant elongation in the latency of P 100 in pattern VEP (> 118 ms, 3 x SD), and significant reduction in mean light sensitivity (MS) in central visual field. MRI revealed demyelinisation in cortex and/or spinal cord of all patients and demyelinating lesion in optic nerve of one patient. There was no Gd-DTPA enhancement. In statistical analysis there was no correlation between results of pattern VEP, IMR, morphology of optic disc, and duration of SM, stage of the disease (in Kurtzke gradation scale) or age of patient. In regression analysis there were statistically significant relationships (p < 0.05) between results of central static perimetry, duration and stage of disease.

Adult↗

PubMed1998

A 16-element phased-array head coil.

Volume-array coils offer increased signal-to-noise ratio (SNR) over standard volume coils near the array elements while preserving the SNR at the center of the volume. As the number of array elements is increased, the SNR advantage as well as the complexity of actually constructing the array increases also. In this study, a 16-channel receive-only array for imaging of the brain is demonstrated and compared to a circularly polarized (CP) head coil of similar shape and diameter. The array was formed from a 2 x 8 grid of square elements placed on a cylindrical form. Mutual coupling was minimized by a combination of overlapping element placement and current-reducing matching networks. Simultaneous data acquisition from the 16 individual elements was performed using a four-channel receiver system with each channel time domain multiplexed by a factor of 4. Theoretical and experimental comparisons between the array and a standard CP head coil show that the array offers an increase in SNR of nearly a factor of 3 near its surface while maintaining a comparable SNR to that of the CP head coil in the center of the region of interest.

Brain↗

PubMed2003

Analysis of protein interactions using fluorescence technologies.

Biophotonics techniques, especially those involving fluorescence, are widely used in proteomics to characterize the in vitro interactions between proteins in high-throughput mode. On the other hand, fluorescence-based imaging studies often show that protein activity is regulated through large protein complexes that transiently form at specific sites in the cell. One could therefore argue that a systematic functional analysis of the human proteome requires technologies that are capable of time and spatially resolved, multiplexed analysis of protein interactions within cells.

Fluorescence Resonance Energy Transfer↗

PubMed2000

Cross talk in holographic memories with lensless phase-conjugate holograms.

Recently holographic memory with lensless phase-conjugate holograms has attracted much attention because it opens up the possibility of compact holographic memories. We investigate cross-talk noise in compact holographic memories with angular multiplexing. It turns out that the optimum angular separation is the same as that for the Fourier plane hologram in the leading order and that the noise-to-signal ratio is independent of the positions in the output plane, similar to the case of the image plane hologram.

Journal Article↗

PubMed2006

Coaxial holographic data storage without recording the dc components.

A technique of recovering the data pages from Fourier holograms recorded without the dc components is demonstrated theoretically and experimentally by use of a coaxial holographic storage system. A reconstructed image is obtained by adding a phase-modulated dc component of the signal beam on reading. The bit error rate of the reconstructed image is comparable with that for the hologram recorded with the dc component as well. Since high intensities of the dc components are not recorded in this technique, the dynamic range of the recording media can be saved, which potentially contributes to increasing the number of multiplexed holograms.

Journal Article↗

PubMed2005

[Detection of integration status of human papillomavirus 16 in cervical precancerous lesions].

OBJECTIVE: To investigate the prevalence of integration of human papillomavirus 16 (HPV16) DNA into the host genome in cervical squamous intraepithelial lesions (SIL). METHODS: Multiplex PCR was used to detect the HPV/HPV16 infection and integration status of HPV16 in the surplus cells from liquid-based cytological samples from 108 patients with cervical cancer precursor lesions. Consensus primers GP5+/GP6+ were used to amplify a 150 bp long fragment in the conserved region of the HPV L1 gene so as to detect the presence pf HPV. Scion Image 4.0 electrophoresis image analysis soft was used to calculate the E2/E6 ratio so as to evaluate the episomal and integrated status of HPV16 infection: in episomal form, both targets should be equivalent, and in integrated form, E2 gene would be absent, while in mixed form of episomal/integrated mixed form, the copy number of E2 would be less than that of E6. RESULTS: Sixty-two out of the 108 patients (57.41%) had HPV infection. HPV16 were found in 32 of the 108 samples (29.63%). Among the 32 cases HPV16 DNA was exclusively episomal in 15 cases (46.88%), concomitant in 13 cases (40.62%), and integrated in 4 cases (12.50%). The prevalence of integrated and/or concomitant forms of HPV-16 DNA increased with progression of cervical disease. The prevalence of integrated form was 54.55% in the patients of CIN3 type, 50.00% in CIN2 type, 28.07% in CIN1 type, and 11.54% in the inflammatory type with significant differences between any 2 groups (all P < 0.01). CONCLUSIONS: HPV16 integration into the host genome is already present in some of CIN lesions. The multiplex PCR estimation of the HPV L1, HPV16 E2, E6 genes and E2/E6 ratio could be a simple method for detecting HPV/HPV16 infection and its integration status in liquid-based residual samples. It would be a helpful complementary tool for cytological screening to identify those patients at high risk of developing high-grade squamous intraepithelial lesions and cervical cancer.

Adult↗

PubMed2007

Dispersion multiplexing with broadband filtering for miniature spectrometers.

We replace the traditional grating used in a dispersive spectrometer with a multiplex holographic grating to increase the spectral range sensed by the instrument. The multiplexed grating allows us to measure three different, overlapping spectral bands on a color digital focal plane. The detector's broadband color filters, along with a computational inversion algorithm, let us disambiguate measurements made from the three bands. The overlapping spectral bands allow us to measure a greater spectral bandwidth than a traditional spectrometer with the same sized detector. Additionally, our spectrometer uses a static coded aperture mask in the place of a slit. The aperture mask allows increased light throughput, offsetting the photon loss at the broadband filters. We present our proof-of-concept dispersion multiplexing spectrometer design with experimental measurements to verify its operation.

Algorithms↗

PubMed2026

Spatial proteomic mapping of the human and mouse retina using IBEX.

We generated a comparative spatial proteomic atlas of the human and mouse retina using a highly multiplexed immunohistochemistry technique called iterative bleaching extends multiplexity (IBEX). We refined the IBEX workflow by integrating an antibody dissociation option alongside chemical bleaching. This dual strategy enabled removal of the entire antibody complex, permitting the flexible use of antibodies from the same host species across iterative cycles. We coupled this workflow with super-resolution imaging via deconvolution and applied it to the retina of healthy humans and WT mice and the Crb1rd8 mouse model. We successfully imaged over 25 protein markers on human and mouse tissue sections, generating spatial atlases of the major retinal cell populations. Cross-species protein expression was compared to scRNA-seq datasets to identify protein and transcript disparities. Super-resolution IBEX delineated the ultrastructural features of the outer limiting membrane (OLM), identifying CD44 as a core structural component tightly colocalized with a highly organized F-actin belt within Müller glial endfeet. Using the Crb1rd8 mouse model, disruption of this complex was spatially associated with rosette formation and OLM structural failure. In summary, spatial proteomic atlases of the human and mouse retina were used to reveal insights into the arrangement of major retinal cell populations and OLM structure.

Animals↗

PubMed2006

Multispectral imaging of clinically relevant cellular targets in tonsil and lymphoid tissue using semiconductor quantum dots.

Determination of the expression and spatial distribution of molecular epitopes, or antigens, in patient tissue specimens has substantially improved the pathologist's ability to classify disease processes. Certain disease pathophysiologies are marked by characteristic increased or decreased expression of developmentally controlled antigens, defined as Cluster of Differentiation markers, that currently form the foundation for understanding lymphoid malignancies. While chromogens and organic fluorophores have been utilitized for some time in immunohistochemical analyses, developments in synthetic, inorganic fluorophore semiconductors, namely quantum dots, offer a versatile alternative reporter system. Quantum dots are stable fluorophores, are resistant to photobleaching, and are attributed with wide excitation ranges and narrow emission spectra. To date, routinely processed, formalin-fixed tissues have only been probed with two quantum dot reporters simultaneously. In the present study, streptavidin-conjugated quantum dots with distinct emission spectra were tested for their utility in identifying a variety of differentially expressed antigens (surface, cytoplasmic, and nuclear). Slides were analyzed using confocal laser scanning microscopy, which enabled with a single excitation wavelength (488 nm argon laser) the detection of up to seven signals (streptavidin-conjugated quantum dots 525, 565, 585, 605, 655, 705 and 805 nm) plus the detection of 4'6-DiAmidino-2-PhenylIndole with an infra-red laser tuned to 760 nm for two photon excitation. Each of these signals was specific for the intended morphologic immunohistochemical target. In addition, five of the seven streptavidin-conjugated quantum dots tested (not streptavidin-conjugated quantum dots 585 or 805 nm) were used on the same tissue section and could be analyzed simultaneously on routinely processed formalin-fixed, paraffin-embedded sections. Application of this multiplexing method will enable investigators to explore the clinically relevant multidimensional cellular interactions that underlie diseases, simultaneously.

Antigens↗

PubMed2000

Familial cavernous hemangioma: An expanding ocular spectrum.

OBJECTIVE: To describe the clinical and genetic findings in a family with multiple cases of cavernous hemangiomas. DESIGN: Investigational clinical and genetic study in which 3 generations of a family consisting of 12 members were screened with magnetic resonance brain imaging, dilated ophthalmoscopic examination, and cutaneous survey coupled with linkage analysis to determine affected individuals and to better define manifestations of this neuro-oculo-cutaneous syndrome. RESULTS: The proband had multiple cerebral cavernous hemangiomas and a choroidal hemangioma. Her son was found to harbor a retinal cavernous hemangioma. The proband's sister manifested a cerebral cavernous hemangioma, cutaneous hemangiomas, and a presumed choroidal hemangioma; her daughter demonstrated radiological findings suggestive of a cerebral cavernous hemangioma. The father of the proband demonstrated multiple, cutaneous hemangiomas. The remaining family members were free of lesions. The 7q locus could not be excluded as harboring the causative gene. CONCLUSIONS: This family may have a dominantly inherited neuro-oculo-cutaneous condition of cavernous hemangiomas with variable expressivity. The presence of choroidal hemangiomas in this phacomatosis has not been described previously to our knowledge. CLINICAL RELEVANCE: The presence of either retinal cavernous or choroidal hemangioma should alert the physician to search for features suggestive of systemic and familial involvement; either lesion may constitute the ocular component of the neuro-oculo-cutaneous phacomatosis, sometimes referred to as cavernoma multiplex. Arch Ophthalmol. 2000;118:969-973

Adult↗

PubMed2004

Multiplexed wavelet transform technique for detection of microcalcification in digitized mammograms.

Wavelet transform (WT) is a potential tool for the detection of microcalcifications, an early sign of breast cancer. This article describes the implementation and evaluates the performance of two novel WT-based schemes for the automatic detection of clustered microcalcifications in digitized mammograms. Employing a one-dimensional WT technique that utilizes the pseudo-periodicity property of image sequences, the proposed algorithms achieve high detection efficiency and low processing memory requirements. The detection is achieved from the parent-child relationship between the zero-crossings [Marr-Hildreth (M-H) detector] /local extrema (Canny detector) of the WT coefficients at different levels of decomposition. The detected pixels are weighted before the inverse transform is computed, and they are segmented by simple global gray level thresholding. Both detectors produce 95% detection sensitivity, even though there are more false positives for the M-H detector. The M-H detector preserves the shape information and provides better detection sensitivity for mammograms containing widely distributed calcifications.

Algorithms↗

PubMed2002

[Octreotide therapy in multiple endocrine neoplasia type-1].

In multiplex endocrine neoplasia type 1, hyperparathyroidism, pancreas tumor and pituitary tumor are generally combined. The authors report two patients with this syndrome, in whom overproduction of parathormone and gastrin was detected, and parathyroid adenomas were detected by parathyroid scintigraphy. Pancreatic adenomas were discovered with somatostatin receptor scintigraphy or magnetic resonance imaging. Hyperprolactinaemia without pituitary tumor in the first case, and prolactinoma in the second case, as well as nonfunctioning adrenal adenomas in both cases were also observed. After several unsuccessful surgical interventions a long-term octreotide (Sandostatin, Novartis) treatment was started; in the first patient subcutaneous injection was given for 6 months, then the treatment was continued with the long-acting intramuscular preparation (Sandostatin LAR, Novartis). The second patient received long-acting octreotide from the beginning of medical therapy. The authors intended to obtain data about the effects of this therapy on all overproduced hormones. In the first case, a 6-months treatment with subcutaneous octreotide surprisingly resulted not only in a decrease of serum gastrin, but also in that of parathormone level. In the second case, serum gastrin was normalized, but parathormone did not change. The levels of prolactin and adrenocortical hormones were not affected. At present, the two patients are without any symptoms of their disease.

Antineoplastic Agents, Hormonal↗

PubMed2005

Geometric superresolution by code division multiplexing.

In many highly resolved optical systems the resolution is limited not by the optics but by the CCD's nonzero pixel size. As a result, overall resolution is decreased. Here we propose a novel approach to enhancing resolution beyond the limit set by the CCD's pixels. This method does not involve additional mechanical elements, such as those used for microscans. In this scheme neither the CCD nor additional elements are moved. The geometric superresolving procedure is based on code-division multiplexing, with all its inherent benefits, such as relative noise immunity to single-tone interference. A setup is proposed for coherent and incoherent illumination, with slight modifications for the latter. A theoretical analysis of the setup is presented and compared with empirical results. This scheme is shown to enhance one-dimensional image resolution with the use of only a simple mask that doubles image resolution. This method can easily be expanded to two-dimensional images and to resolution-enhancement factors greater than 2.

Journal Article↗

PubMed2003

A novel experimental design for comparative two-dimensional gel analysis: two-dimensional difference gel electrophoresis incorporating a pooled internal standard.

The comparison of two-dimensional (2-D) gel images from different samples is an established method used to study differences in protein expression. Conventional methods rely on comparing images from at least 2 different gels. Due to the high variation between gels, detection and quantification of protein differences can be problematic. Two-dimensional difference gel electrophoresis (Ettan trade mark DIGE) is an emerging technique for comparative proteomics, which improves the reproducibility and reliability of differential protein expression analysis between samples. In the application of DIGE different samples are labelled with mass and charge matched spectrally resolvable fluorescent dyes and are then separated on the same 2-D gel. Using an Escherichia coli lysate "spiked" with varying amounts of four different known proteins, we have tested a novel experimental design that exploits the sample multiplexing capabilities of DIGE, by including a standard sample in each gel. The standard sample comprises equal amounts of each sample to be compared and was found to improve the accuracy of protein quantification between samples from different gels allowing accurate detection of small differences in protein levels between samples.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2005

The bronchiolar epithelium as a prominent source of pro-inflammatory cytokines after lung irradiation.

PURPOSE: To study in detail the temporal and spatial release of the pro-inflammatory cytokines tumor necrosis factor alpha, interleukin (IL)-1alpha, and IL-6 in the lung tissue of C57BL/6 mice after thoracic irradiation with 12 Gy. METHODS AND MATERIALS: C57BL/6J mice were exposed to either sham irradiation or a single fraction of 12 Gy delivered to the thorax. Treated and sham-irradiated control mice were killed at 0.5 h, 1 h, 3 h, 6 h, 12 h, 24 h, 48 h, 72 h, 1 week, 2 weeks, 4 weeks, 8 weeks, 16 weeks, and 24 weeks post-irradiation (p.i.). Real-time multiplex reverse transcriptase polymerase chain reaction was established to evaluate the relative messenger RNA (mRNA) expression of TNF-alpha, IL-1alpha, and IL-6 in the lung tissue of the mice (compared with nonirradiated lung tissue). Immunohistochemical detection methods (alkaline phosphatase anti-alkaline phosphatase, avidin-biotin-complex [ABC]) and automated image analysis were used to quantify the protein expression of TNF-alpha, IL-1alpha, and IL-6 in the lung tissue (percentage of the positively stained area). RESULTS: Radiation-induced release of the pro-inflammatory cytokines TNF-alpha, IL-1alpha, and IL-6 in the lung tissue was detectable within the first hours after thoracic irradiation. We observed statistically significant up-regulations for TNF-alpha at 1 h p.i. on mRNA (4.99 +/- 1.60) and at 6 h p.i. on protein level (7.23% +/- 1.67%), for IL-1alpha at 6 h p.i. on mRNA (11.03 +/- 0.77) and at 12 h p.i. on protein level (27.58% +/- 11.06%), for IL-6 at 6 h p.i. on mRNA (6.0 +/- 3.76) and at 12 h p.i. on protein level (7.12% +/- 1.93%). With immunohistochemistry, we could clearly demonstrate that the bronchiolar epithelium is the most prominent source of these inflammatory cytokines in the first hours after lung irradiation. During the stage of acute pneumonitis, the bronchiolar epithelium, as well as inflammatory cells in the lung interstitium, produced high amounts of TNF-alpha (with the maximal value at 4 weeks p.i.: 9.47% +/- 1.78%), IL-1alpha (with the peak value at 8 weeks p.i.: 14.76% +/- 7.77%), and IL-6 (with the peak value at 8 weeks p.i.: 4.28% +/- 1.33%). CONCLUSIONS: In the present study we have clearly demonstrated the immediate expression of the pro-inflammatory cytokines TNF-alpha, IL-1alpha, and IL-6 in the bronchiolar epithelium in the first hours after lung irradiation. A second, long-lasting release of these cytokines by the bronchiolar and alveolar epithelium, as well as by inflammatory cells, was observed at the onset of acute pneumonitis. Therefore, we postulate that lung irradiation causes immediate epithelial reaction, with the bronchiolar epithelium becoming a significant source of pro-inflammatory cytokines capable of promoting inflammation through recruitment and activation of inflammatory cells.

Animals↗

PubMed2000

Direct haplotyping of kilobase-size DNA using carbon nanotube probes.

We have implemented a method for multiplexed detection of polymorphic sites and direct determination of haplotypes in 10-kilobase-size DNA fragments using single-walled carbon nanotube (SWNT) atomic force microscopy (AFM) probes. Labeled oligonucleotides are hybridized specifically to complementary target sequences in template DNA, and the positions of the tagged sequences are detected by direct SWNT tip imaging. We demonstrated this concept by detecting streptavidin and IRD800 labels at two different sequences in M13mp18. Our approach also permits haplotype determination from simple visual inspection of AFM images of individual DNA molecules, which we have done on UGT1A7, a gene under study as a cancer risk factor. The haplotypes of individuals heterozygous at two critical loci, which together influence cancer risk, can be easily and directly distinguished from AFM images. The application of this technique to haplotyping in population-based genetic disease studies and other genomic screening problems is discussed.

Alleles↗

PubMed2003

Identification of forensic samples by using an infrared-based automatic DNA sequencer.

We have recently introduced a new protocol for analyzing all core loci of the Federal Bureau of Investigation's (FBI) Combined DNA Index System (CODIS) with an infrared (IR) automatic DNA sequencer (LI-COR 4200). The amplicons were labeled with forward oligonucleotide primers, covalently linked to a new infrared fluorescent molecule (IRDye 800). The alleles were displayed as familiar autoradiogram-like images with real-time detection. This protocol was employed for paternity testing, population studies, and identification of degraded forensic samples. We extensively analyzed some simulated forensic samples and mixed stains (blood, semen, saliva, bones, and fixed archival embedded tissues), comparing the results with donor samples. Sensitivity studies were also performed for the four multiplex systems. Our results show the efficiency, reliability, and accuracy of the IR system for the analysis of forensic samples. We also compared the efficiency of the multiplex protocol with ultraviolet (UV) technology. Paternity tests, undegraded DNA samples, and real forensic samples were analyzed with this approach based on IR technology and with UV-based automatic sequencers in combination with commercially-available kits. The comparability of the results with the widespread UV methods suggests that it is possible to exchange data between laboratories using the same core group of markers but different primer sets and detection methods.

DNA Fingerprinting↗

PubMed1996

Arthrogryposis multiplex congenita and bilateral parietal polymicrogyria in association with the intrauterine death of a twin.

A case of neurogenic arthrogryposis multiplex congenita (AMC) with associated neuronal migration abnormalities is described. A child with neurogenic AMC and developmental delay presented with late onset of seizures. The first trimester of the mother's pregnancy was marked by an episode of gastro-enteritis and the intrauterine death of a twin fetus. Computer tomography (CT) and magnetic resonance (MR) imaging demonstrated abnormal neuronal migration consisting of bilateral parietal polymicrogyria, and an isolated grey matter heterotopia.

Age of Onset↗