PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “single platform”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2025

SLB-msSIM: A Spectral Library-Based Multiplex Segmented SIM Platform for Single-Cell Proteomic Analysis.

Mass spectrometry (MS)-based single-cell proteomics, while highly challenging, offers unique potential for a wide range of applications to interrogate cellular heterogeneity, trajectories, and phenotypes at a functional level. We report here the development of the spectral library-based multiplex segmented selected ion monitoring (SLB-msSIM) method, a conceptually unique approach with significantly enhanced sensitivity and robustness for single-cell analysis. The single-cell MS data is acquired by a multiplex segmented selected ion monitoring (msSIM) technique, which sequentially applies multiple isolation cycles with the quadrupole using a wide isolation window in each cycle to accumulate and store precursor ions in the C-trap for a single scan in the Orbitrap. Proteomic identification is achieved through spectral matching using a well-defined spectral library. We applied the SLB-msSIM method to interrogate cellular heterogeneity in various pancreatic cancer cell lines, revealing common and distinct functional traits among PANC-1, MIA-PaCa2, AsPc-1, HPAF, and normal HPDE cells. Furthermore, for the first time, our novel data revealed the diverse cell trajectories of individual PANC-1 cells during the induction and reversal of epithelial-mesenchymal transition (EMT). Collectively, our results demonstrate that SLB-msSIM is a highly sensitive and robust platform, applicable to a wide range of instruments for single-cell proteomic studies. SUMMARY: We present the SLB-msSIM method, a conceptually unique approach in mass spectrometry-based single-cell proteomics that significantly enhances sensitivity and robustness. This innovative platform enables detailed analysis of the proteome landscape, capturing cellular heterogeneity, trajectories, and phenotypes at a single-cell resolution. Utilizing the SLB-msSIM technique, we identified both common and distinct functional traits among various pancreatic cancer cell lines and normal cells. Moreover, our study unveiled new insights into the diverse cell trajectories of individual cancer cells during the induction and reversal of epithelial-mesenchymal transition (EMT). In summary, the SLB-msSIM method offers a highly sensitive and robust platform for single-cell proteomic studies, with broad applicability across different instruments.

Single-Cell Analysis↗
PubMed1998

Neuroethologic differences in sleep deprivation induced by the single- and multiple-platform methods.

It has been proposed that the multiple-platform method (MP) for desynchronized sleep (DS) deprivation eliminates the stress induced by social isolation and by the restriction of locomotion in the single-platform (SP) method. MP, however, induces a higher increase in plasma corticosterone and ACTH levels than SP. Since deprivation is of heuristic value to identify the functional role of this state of sleep, the objective of the present study was to determine the behavioral differences exhibited by rats during sleep deprivation induced by these two methods. All behavioral patterns exhibited by a group of 7 albino male Wistar rats submitted to 4 days of sleep deprivation by the MP method (15 platforms, spaced 150 mm apart) and by 7 other rats submitted to sleep deprivation by the SP method were recorded in order to elaborate an ethogram. The behavioral patterns were quantitated in 10 replications by naive observers using other groups of 7 rats each submitted to the same deprivation schedule. Each quantification session lasted 35 min and the behavioral patterns presented by each rat over a period of 5 min were counted. The results obtained were: a) rats submitted to the MP method changed platforms at a mean rate of 2.62 +/- 1.17 platforms h-1 animal-1; b) the number of episodes of noninteractive waking patterns for the MP animals was significantly higher than that for SP animals (1077 vs 768); c) additional episodes of waking patterns (26.9 +/- 18.9 episodes/session) were promoted by social interaction in MP animals; d) the cumulative number of sleep episodes observed in the MP test (311) was significantly lower (chi-square test, 1 d.f., P < 0.05) than that observed in the SP test (534); e) rats submitted to the MP test did not show the well-known increase in ambulatory activity observed after the end of the SP test; f) comparison of 6 MP and 6 SP rats showed a significantly shorter latency to the onset of DS in MP rats (7.8 +/- 4.3 and 29.0 +/- 25.0 min, respectively; Student t-test, P < 0.05). We conclude that the social interaction occurring in the MP test generates additional stress since it increases the time of forced wakefulness and reduces the time of rest promoted by synchronized sleep.

Adrenocorticotropic Hormone↗
PubMed2005

Single-step affinity purification of toxic and non-toxic proteins on a fluidics platform.

Single-step fusion-based affinity purification of proteins with pH-controllable linkers was carried out in a fluidic device. The linkers were previously derived from self-splicing protein elements called inteins. Two different linkers were generated to solve two distinct separation problems: one for rapid single-step affinity purification of a wide range of proteins, and the other specifically for the purification of cytotoxic proteins. Scale-down factors of 185 resulted in separations in a 27 microl bed-volume. A rotating CD format was chosen because of its simplicity in effecting fluid movement through centrifugal force without the complications associated with electro-osmosis and other pumping methods. The design and fabrication of the fluidic device and the protein purification process are described. This work, which demonstrates the purification of active proteins by two distinct fluidic separations, is widely applicable to small-scale massively parallel proteomic separations.

Chromatography, Affinity↗
PubMed2000

Brånemark System Wide Platform implants for single molar replacement: clinical evaluation of prospective and retrospective materials.

BACKGROUND: The use of oral implants for single tooth replacement has become a predictable treatment modality. As single tooth loss is most common in posterior areas of the jaws, the use of the protocol is of specific interest in those regions. New implant designs aimed at this purpose have also been introduced. PURPOSE: The aim of the study was to present the outcomes for wide diameter implant treatment when being used in posterior areas of the jaws. MATERIALS AND METHODS: This paper presents the 3-year results of a prospective multicenter study (three clinics; n = 38 implants) and the 1-year results from a retrospective multicenter study (two clinics; n = 20 implants) on wide diameter implants for single molar replacement. Based on the hypothesis that dense bone in posterior mandibles would benefit from careful surgery and longer remodeling time, the influences of surgical technique and healing time on implant success and bone resorption were particularly addressed. RESULTS: The outcome demonstrated a good predictability for Brånemark System Wide Platform implants, at least short term, when used as single molar support (prospective group cumulative success rate [CSR] = 92% after 3 years; retrospective group CSR = 95% after 1 year). The increased mechanical strength of the wide platform implant/abutment complex also turned out to be important for mechanical stability. CONCLUSIONS: The study indicated that it was important to carefully perform surgery in posterior mandibles in order to preserve and optimally use the existing dense bone. It was suggested that from bone healing and remodeling aspects, posterior mandibles may be more demanding to handle than corresponding areas of maxillae.

Adult↗
PubMed1997

Absence of oxidative stress following paradoxical sleep deprivation in rats.

Paradoxical sleep deprivation was performed on rats using platform technique to investigate the oxidative process associated with it. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total glutathione (GSH) and malondialdehyde production were measured in brain of rats under control conditions (C) and those on single large platforms (SLP), multiple large platforms (MLP), single small platforms (SSP) and multiple small platforms (MSP) groups. SOD, CAT and GPx brain activity and malondialdehyde production were not modified by any of the procedures. Brain GSH, however, was significantly reduced in both SSP and SLP groups. These results suggest that paradoxical sleep deprivation per se is not associated with oxidative damage. The observed alterations could be attributed to factors such as immobilization and social isolation present in the single platform techniques.

Animals↗
PubMed1996

Unified theory regarding A/P and M/L balance in quiet stance.

1. Control of posture in quiet stance has been quantified by center of pressure (COP) changes in the anterior-posterior (A/P) and medial-lateral (M/L) directions from a single force platform. Recording from a single force platform, researchers are unable to recognize two separate mechanisms that become evident when two force platforms are used. Depending on the stance position taken, many combinations of an ankle mechanism and a hip (load/unload) mechanism are evident. In side-by-side stance, A/P balance is totally under ankle (plantar/dorsiflexor) control, whereas M/L balance is under hip (abductor/adductor) control. In tandem stance, the A/P balance is dominated by the hip mechanism, with mixed and small or sometimes negligible contributions by the ankle plantar/dorsiflexors: for M/L balance, the reverse is evident; ankle invertors/evertors dominate, with mixed and small contribution from the hip load/unload mechanism. In an intermediate 45 degrees stance position, both ankle and hip mechanisms contribute to the net balance control in totally different ways. In the M/L direction the two strategies reinforce, whereas in the A/P direction the ankle mechanism must overcome and cancel most of the inappropriate contribution by the hip load/unload mechanism. A spatial plot of the separate mechanisms reveals the fact that the random-looking COP scatter plot is nothing more than a spatial and temporal summation of two separate spatial plots. A straight line joining the individual COPs under each foot is the load/unload line controlled by the hip mechanism. At right angles to this load/unload line in the side-by-side and tandem positions is the independent control line by the ankle muscles. In an intermediate standing position, the separate control lines exist, but now the ankle control is not orthogonal to the load/unload line; rather, it acts at an angle of approximately 60 degrees. The direction of these ankle control and load/unload lines also allows us to pinpoint the muscle groups responsible at the ankle and hip in any of the stance positions.

Adult↗
PubMed2004

The LSM 510 META - ConfoCor 2 system: an integrated imaging and spectroscopic platform for single-molecule detection.

Fluorescence Correlation Spectroscopy (FCS) has developed into a routine method to quantitatively study diffusion of molecules and kinetic processes. FCS has recently become popular to complement live cell imaging with biophysical information. The enabling technology has been commercially realised by combining laser scanning microscopes and fluorescence correlation spectrometers in one integrated platform. This article provides an overview of the Zeiss solution of such a combined instrument, the LSM 510 META / ConfoCor 2 system. We focus on the instrumental set up as well as technical advances and improvements in the software that controls FCS data acquisition and evaluation. In addition, we outline the calibration of the instrument and the work flow for data analysis with emphasis on in vivo pharmacological applications.

Calibration↗
PubMed2006

Accuracy of multiplexed Illumina platform-based single-nucleotide polymorphism genotyping compared between genomic and whole genome amplified DNA collected from multiple sources.

Association studies designed to identify the genetic determinants underlying complex disease increasingly require sustainable high-quality DNA resources for large-scale single-nucleotide polymorphism (SNP) genotyping. Recent studies have shown that genomic DNA (gDNA) suitable for SNP genotyping can be obtained from buccal cells and from dried blood spots on Guthrie cards. Further, successful SNP genotyping has been done using the reaction product of multiple displacement amplification of gDNA. We evaluated genotype consistency on the Illumina genotyping platform for 717 to 1,744 SNP loci between replicate samples of gDNA and whole genome amplified DNA (wgaDNA) from a variety of sources. Nine healthy adults provided peripheral blood via venipuncture and buccal cells by mouth rinse. DNA was also obtained from urothelial cells in urine samples from five of the nine subjects. gDNA was extracted from all samples, wgaDNA was generated from each gDNA, and all samples were genotyped. To assess SNP genotyping accuracy of DNA obtained from dried blood spots, gDNA was extracted, amplified, and genotyped from peripheral blood samples and paired Guthrie card samples were obtained from eight childhood leukemia patients. Call rates and replicate concordances for all sample types, regardless of amplification, were >97%, with most sample types having call rates and replicate concordances >99%. Using the gDNA from blood samples as the reference for concordances calculated for all other sample types, we observed concordances >98% regardless of sample type or amplification. We conclude that highly multiplexed Illumina genotyping may be done on gDNA and wgaDNA obtained from whole blood, buccal samples, dried blood spots on Guthrie cards, and possibly even urine samples, with minimal misclassification.

Aged↗
PubMedDate not supplied

A point-of-care analyzer for blood gases, Chem 7, Hct, and Hgb.

A single POC analyzer can satisfy the entire test menu needs of clinicians in a wide variety of settings, including OR, ED, ICU, and NICU. A single POC platform provides complete diagnostic information, reduces turnaround time to less than 2 min, reduces blood loss, and streamlines the performance of POC testing. For the laboratory, a single platform simplifies implementation and management of POC testing while increasing the tasks of meeting regulatory compliance.

Blood Chemical Analysis↗
PubMed2003

Children with Fetal Alcohol Syndrome are impaired at place learning but not cued-navigation in a virtual Morris water task.

We employed a computerized (virtual) Morris water task (VMWT) to measure place learning and cued-navigation in eight adolescent males (9.5-16.5 years old) diagnosed with Fetal Alcohol Syndrome (FAS). Eight adolescent males matched for age and ethnicity with no history of prenatal alcohol exposure served as controls. Participants were trained to navigate to a hidden platform in a fixed location relative to a set of four conspicuous extramaze cues. After 20 hidden platform trials, a single no-platform probe trial was conducted, followed by 8 trials during which the platform was visible (cued-navigation). The FAS group traveled further than controls to navigate to the hidden platform during training. During the probe trial, controls navigated more directly to the platform region and persisted in searching where the platform had been more than the FAS group. Cued-navigation was comparable in both groups, suggesting that group differences in place learning were not attributable to visual-motor or motivational deficits in the FAS subjects. This pattern of impaired place learning and spared cued-navigation is similar to that reported in rats exposed to ethanol during periods of prenatal or early postnatal brain growth, as well as in animals with hippocampal damage.

Adolescent↗
PubMed2000

Cytofluorometric methods for assessing absolute numbers of cell subsets in blood. European Working Group on Clinical Cell Analysis.

The enumeration of absolute levels of cells and their subsets in clinical samples is of primary importance in human immunodeficiency virus (HIV)+ individuals (CD4+ T- lymphocyte enumeration), in patients who are candidates for autotransplantation (CD34+ hematopoietic progenitor cells), and in evaluating leukoreduced blood products (residual white blood cells). These measurements share a number of technical options, namely, single- or multiple-color cell staining and logical gating strategies. These can be accomplished using single- or dual-platform counting technologies employing cytometric methods. Dual-platform counting technologies couple the percentage of positive cell subsets obtained by cytometry and the absolute cell count obtained by automated hematology analyzers to derive the absolute value of such subsets. Despite having many conceptual and technical limitations, this approach is traditionally considered as the reference method for absolute cell count enumeration. As a result, the development of single-platform technologies has recently attracted attention with several different technical approaches now being readily available. These single-platform approaches have less sources of variability. A number of reports clearly demonstrate that they provide better coefficients of variation (CVs) in multicenter studies and a lower chance to generate aberrant results. These methods are therefore candidates for the new gold standard for absolute cell assessments. The currently available technical options are discussed in this review together with the results of some cross-comparative studies. Each analytical system has its own specific requirements as far as the dispensing precision steps are concerned. The importance of precision reverse pipetting is emphasized. Issues still under development include the establishment of the critical error ranges, which are different in each test setting, and the applicability of simplified low-cost techniques to be used in countries with limited resources.

Antigens, CD34↗
PubMed2005

An analysis of identical single-nucleotide polymorphisms genotyped by two different platforms.

The overlap of 94 single-nucleotide polymorphisms (SNP) among the 4,720 and 11,120 SNPs contained in the linkage panels of Illumina and Affymetrix, respectively, allows an assessment of the discrepancy rate produced by these two platforms. Although the no-call rate for the Affymetrix platform is approximately 8.6 times greater than for the Illumina platform, when both platforms make a genotypic call, the agreement is an impressive 99.85%. To determine if disputed genotypes can be resolved without sequencing, we studied recombination in the region of the discrepancy for the most discrepant SNP rs958883 (typed by Illumina) and tsc02060848 (typed by Affymetrix). We find that the number of inferred recombinants is substantially higher for the Affymetrix genotypes compared to the Illumina genotypes. We illustrate this with pedigree 10043, in which 3 of 7 versus 0 of 7 offspring must be double recombinants using the genotypes from the Affymetrix and the Illumina platforms, respectively. Of the 36 SNPs with one or more discrepancies, we identified a subset that appears to cluster in families. Some of this clustering may be due to the presence of a second segregating SNP that obliterates a XbaI site (the restriction enzyme used in the Affymetrix platform), resulting in a fragment too long (>1,000 bp) to be amplified.

Female↗
PubMed2004

Total body centre of mass displacement estimated using ground reactions during transitory motor tasks: application to step ascent.

A double integration technique is presented that estimates whole body centre of mass (CoM) displacement from signals of a single force platform, compensating for the drift and low frequency noise inherent in the signals. The technique is composed of two different integration techniques, which may also be used separately, and is applied to transitory motor tasks with known initial and final conditions such as step ascent and descent, single step, etc. First, the lowest frequencies within the force platform signals and considered not to be associated with actual movement are filtered out. Second, a regular and a time-reversed double integration are performed and weighted against each other. The technique's accuracy was assessed using computer generated force platform signals that were artificially perturbed. Experimental data were used to compare the estimated CoM displacement to that obtained from a regular double integration and from segmental analysis performed on stereophotogrammetric data. It was shown that the proposed technique's CoM displacement estimates were more repeatable and up to 50% more accurate than those of a regular double integration. Moreover, the CoM displacement estimated using a single force platform and the proposed technique was found to be not statistically different from that obtained with more demanding measurement and processing techniques such as stereophotogrammetry and segmental analysis.

Adult↗
PubMed2003

A versatile microfabricated platform for electrophoresis of double- and single-stranded DNA.

We demonstrate a versatile microfabricated electrophoresis platform, incorporating arrays of integrated on-chip electrodes, heaters, and temperature sensors. This design allows a range of different sieving gels to be used within the same device to perform separations involving both single- and double-stranded DNA over distances on the order of 1 cm. We use this device to compare linear and cross-linked polyacrylamide, agarose, and thermo-reversible Pluronic-F127 gels on the basis of gel casting ease, reusability, and overall separation performance using a 100 base pair double-stranded DNA ladder as a standard sample. While cross-linked polyacrylamide matrices provide consistently high-quality separations in our system over a wide range of DNA fragment sizes, Pluronic gels also offer compelling advantages in terms of the ability to remove and reload the gel. Agarose gels offer good separation performance, however, additional care must be exercised to ensure consistent gel properties as a consequence of the need for elevated gel loading temperatures. We also demonstrate the use of denaturing cross-linked polyacrylamide gels at concentrations up to 19% to separate single-stranded DNA fragments ranging in size from 18 to 400 bases in length. Primers differing by 4 bases at a read length of 30 bases can be separated with a resolution of 0.9-1.0 in under 20 min. This level of performance is sufficient to conduct a variety of genotyping assays including the rapid detection of single nucleotide polymorphisms (SNPs) in a microfabricated platform. The ability to use a single microelectrophoresis system to satisfy a wide range of separation applications offers molecular biologists an unprecedented level of flexibility in a portable and inexpensive format.

Acrylic Resins↗
PubMed2005

Sequencing arrays for screening multiple genes associated with early-onset human retinal degenerations on a high-throughput platform.

PURPOSE: To develop and apply microarray-based resequencing technology to detect sequence alterations in multiple autosomal recessive retinal disease genes on a single high-throughput platform. METHODS: Oligonucleotides corresponding to both strands of the target exons and the flanking intron sequences of 29,214 bp from 11 genes associated with autosomal recessive retinitis pigmentosa (arRP) were tiled on 20 x 25-microm microarrays (arRP-I arrays). A total of 155 exons were amplified from 35 arRP patient DNA samples, with each sample being sequenced on an arRP-I chip by hybridization. RESULTS: With the arRP-I arrays, 97.6% of the tiled sequence were determined with more than 99% accuracy and reproducibility. Of the 2.4% unread sequence, 89.5% involved stretches of G or C. In analyzing the 903,140-bp sequence from the 35 patient samples, 506 sequence changes have been detected in which 386 are previously reported alterations, and 120 are novel. In addition to four known causative mutations, six novel sequence changes that are potentially pathogenic were observed. Additional analysis is needed to determine whether these changes are responsible for arRP in these patients. CONCLUSIONS: The use of microarray for sequencing is a novel approach, and the arRP-I chip is the first successful application of this technology for determining sequence alteration in multiple disease-related genes. These arrays can be used for high-throughput genotyping of patients with relevant retinal conditions. In addition, these arrays offer a unique opportunity to interrogate complex patterns of inheritance due to the involvement of more than one gene by screening multiple genes on a single platform.

Base Sequence↗
PubMed2004

Towards preimplantation diagnosis of cystic fibrosis using microarrays.

Cystic fibrosis (CF) is a common indication for preimplantation genetic diagnosis (PGD). A 3-bp deletion (DeltaF508) in the cftr gene, which accounts for approximately 80% of all CF mutations in the Caucasian population, is normally diagnosed in IVF embryos using fluorescent PCR (FL-PCR) and allelic sizing. In PGD, the possibility of using microarrays for genetic diagnosis is largely unexplored. Therefore, the aim of this study was to prove the diagnostic capability of microarrays for PGD, using DeltaF508 as a model mutation. To this end, oligonucleotide probes representing both the normal and DeltaF508 disease alleles were used to construct a single microarray platform. Target DNA, which was generated by PCR and labelled with the fluorescent dye Cy3, was hybridized to the array and the DeltaF508 genotypes assigned from the fluorescence bound to each allelic probe. The performance of the array was evaluated by its ability to detect DeltaF508 mutations in target DNA. Strong binding of the target to the probes was observed, allowing the expected DeltaF508 genotypes to be assigned. The reliability and accuracy of the microarray diagnosis for DeltaF508 was blindly assessed on 10 samples with either a homozygous normal, homozygous affected or heterozygous genotype. All samples were correctly genotyped. In addition, PCR products from a previous PGD case involving DeltaF508 were re-evaluated on the array, with results in complete concordance with allelic sizing methods used to make the original diagnosis. Together, these findings prove the concept that the DeltaF508 mutation of CF can be reliably and accurately diagnosed at the single cell level using microarray analysis. The availability of more cost-effective array platforms comprising mutation probes for common single-gene disorders and a reliable method of whole genome amplification (WGA) would allow PGD to be offered to the majority of PGD patients with minimal or no change to methodology.

Adenine↗
PubMed2006

Dip-pen nanolithography on (bio)reactive monolayer and block-copolymer platforms: deposition of lines of single macromolecules.

The application of atomic force microscopy (AFM) tip-mediated molecular transfer (dip-pen nanolithography or DPN) to fabricate nanopatterned (bio)reactive platforms based on dendrimers on reactive self-assembled monolayer (SAM) and polymer thin films is discussed. The transfer of high-molar-mass polyamidoamine (PAMAM) dendrimers (generation 5) and the rapid in situ covalent attachment of the deposited adsorbates onto reactive N-hydroxysuccinimide (NHS) terminated SAMs on gold and NHS-activated polystyrene-block-poly(tert-butyl acrylate) (PS(690)-b-PtBA(1210)) block copolymer thin films were investigated as strategies to suppress line broadening by surface diffusion in DPN. By exploiting carefully controlled environmental conditions (such as temperature and relative humidity), scan rates, and in particular the covalent attachment of the dendrimers to the reactive films, the observed line broadening and hence the lateral diffusion of dendrimers was substantially less pronounced compared to that observed with DPN of thiols on gold. By this method, high-definition patterns of dendrimers were conveniently fabricated down to 30-nm length scales. The presence of primary amino groups in the deposited dendrimers ultimately offers the possibility to anchor biochemically relevant molecules, such as proteins and polypeptides, to these nanostructured platforms for a wide range of possible applications in the life sciences and in particular for the investigation of controlled cell-surface interactions.

Dendrimers↗