2,093 research outputs found
Laparoscopic Radical Nephrectomy in a Pelvic Ectopic Kidney: Keys to Success
Preoperative imaging to delineate anomalous vascular anatomy is mandatory to perform laparoscopic radical nephrectomy for a pelvic ectopic kidney
System Integration - A Major Step toward Lab on a Chip
Microfluidics holds great promise to revolutionize various areas of biological engineering, such as single cell analysis, environmental monitoring, regenerative medicine, and point-of-care diagnostics. Despite the fact that intensive efforts have been devoted into the field in the past decades, microfluidics has not yet been adopted widely. It is increasingly realized that an effective system integration strategy that is low cost and broadly applicable to various biological engineering situations is required to fully realize the potential of microfluidics. In this article, we review several promising system integration approaches for microfluidics and discuss their advantages, limitations, and applications. Future advancements of these microfluidic strategies will lead toward translational lab-on-a-chip systems for a wide spectrum of biological engineering applications
Multiple tumor suppressors regulate a HIF-dependent negative feedback loop via ISGF3 in human clear cell renal cancer.
Whereas VHL inactivation is a primary event in clear cell renal cell carcinoma (ccRCC), the precise mechanism(s) of how this interacts with the secondary mutations in tumor suppressor genes, including PBRM1, KDM5C/JARID1C, SETD2, and/or BAP1, remains unclear. Gene expression analyses reveal that VHL, PBRM1, or KDM5C share a common regulation of interferon response expression signature. Loss of HIF2α, PBRM1, or KDM5C in VHL-/-cells reduces the expression of interferon stimulated gene factor 3 (ISGF3), a transcription factor that regulates the interferon signature. Moreover, loss of SETD2 or BAP1 also reduces the ISGF3 level. Finally, ISGF3 is strongly tumor-suppressive in a xenograft model as its loss significantly enhances tumor growth. Conversely, reactivation of ISGF3 retards tumor growth by PBRM1-deficient ccRCC cells. Thus after VHL inactivation, HIF induces ISGF3, which is reversed by the loss of secondary tumor suppressors, suggesting that this is a key negative feedback loop in ccRCC. © 2018, Liao et al
Fibered Confocal Microscopy of Bladder Tumors: An ex Vivo Study
Background and Purpose: The inadequacy of white-light cystoscopy to detect flat bladder tumors is well recognized. Great interest exists in developing other imaging technologies to augment or supplant conventional cystoscopy. Fibered confocal microscopy offers the promise of providing in vivo histopathologic information to help distinguish malignant from benign bladder lesions. We report the initial use of this technology to visualize tumors in the human bladder. Materials and Methods: We performed ex vivo fibered confocal imaging of fresh radical cystectomy specimens using the Mauna Kea Technologies Cellvizio system. The findings were compared with results from standard histopathology. Results: The bladders of four patients were imaged using the fibered confocal microscope. Normal and neoplastic urothelium manifested differences in cellular and vascular density. Conclusion: This study demonstrates the feasibility of using fibered confocal microscopy to detect histologic differences between normal and neoplastic urothelium, and establishes a foundation for the use of fiber-based confocal microscopy in clinical studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78112/1/end.2008.0524.pd
Blind study evaluation illustrates utility of the Ion PGM™ system for use in human identity DNA typing
Aim To perform a blind study to assess the capability of
the Ion Personal Genome Machine® (PGM™) system to sequence
forensically relevant genetic marker panels and to
characterize unknown individuals for ancestry and possible
relatedness.
Methods Twelve genomic samples were provided by a
third party for blinded genetic analysis. For these 12 samples,
the mitochondrial genome and three PGM™ panels
containing human identity single nucleotide polymorphisms
(SNPs), ancestry informative SNPs, and short tandem
repeats (STRs) were sequenced on the PGM™ system
and analyzed.
Results All four genetic systems were run and analyzed on
the PGM™ system in a reasonably quick time frame. Completeness
of genetic profiles, depth of coverage, strand
balance, and allele balance were informative metrics that
illustrated the quality and reliability of the data produced.
SNP genotypes allowed for identification of sex, paternal
lineage, and population ancestry. STR genotypes were
shown to be in complete concordance with genotypes
generated by standard capillary electrophoresis-based
technologies. Variants in the mitochondrial genome data
provided information on population background and maternal
relationships.
Conclusion All results from analysis of the 12 genomic
samples were consistent with sample information provided
by the sample providers at the end of the blinded study.
The relatively easy identification of intra-STR allele SNPs offered
the potential for increased discrimination power. The
promising nature of these results warrants full validation
studies of this massively parallel sequencing technology
and its further development for forensic data analysis
Extraordinary Thermoelectric Properties of Topological Surface States in Quantum-Confined Cd3As2 Thin Films
Topological insulators and semimetals have been shown to possess intriguing
thermoelectric properties promising for energy harvesting and cooling
applications. However, thermoelectric transport associated with the Fermi arc
topological surface states on topological Dirac semimetals remains less
explored. In this work, we systematically examine thermoelectric transport in a
series of topological Dirac semimetal Cd3As2 thin films grown by molecular beam
epitaxy. Surprisingly, we find significantly enhanced Seebeck effect and
anomalous Nernst effect at cryogenic temperatures when the Cd3As2 layer is
thin. Combining angle-dependent quantum oscillation analysis,
magnetothermoelectric measurement, transport modelling and first-principles
simulation, we isolate the contributions from bulk and surface conducting
channels and attribute the unusual thermoeletric properties to the topological
surface states. Our analysis showcases the rich thermoelectric transport
physics in quantum-confined topological Dirac semimetal thin films and suggests
new routes to achieving high thermoelectric performance at cryogenic
temperatures
Comparative Analysis of the Glycosylation Profiles of Membrane-Anchored HIV-1 Envelope Glycoprotein Trimers and Soluble gp140
The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer, which consists of the gp120 and gp41 subunits, is the focus of multiple strategies for vaccine development. Extensive Env glycosylation provides HIV-1 with protection from the immune system, yet the glycans are also essential components of binding epitopes for numerous broadly neutralizing antibodies. Recent studies have shown that when Env is isolated from virions, its glycosylation profile differs significantly from that of soluble forms of Env (gp120 or gp140) predominantly used in vaccine discovery research. Here we show that exogenous membrane-anchored Envs, which can be produced in large quantities in mammalian cells, also display a virion-like glycan profile, where the glycoprotein is extensively decorated with high-mannose glycans. Additionally, because we characterized the glycosylation with a high-fidelity profiling method, glycopeptide analysis, an unprecedented level of molecular detail regarding membrane Env glycosylation and its heterogeneity is presented. Each glycosylation site was characterized individually, with about 500 glycoforms characterized per Env protein. While many of the sites contain exclusively high-mannose glycans, others retain complex glycans, resulting in a glycan profile that cannot currently be mimicked on soluble gp120 or gp140 preparations. These site-level studies are important for understanding antibody-glycan interactions on native Env trimers. Additionally, we report a newly observed O-linked glycosylation site, T606, and we show that the full O-linked glycosylation profile of membrane-associated Env is similar to that of soluble gp140. These findings provide new insight into Env glycosylation and clarify key molecular-level differences between membrane-anchored Env and soluble gp140
A Bayesian Nonparametric Approach to Modeling Motion Patterns
The most difficult—and often most essential—
aspect of many interception and tracking tasks is constructing
motion models of the targets to be found. Experts can
often provide only partial information, and fitting parameters
for complex motion patterns can require large amounts
of training data. Specifying how to parameterize complex
motion patterns is in itself a difficult task.
In contrast, nonparametric models are very flexible and
generalize well with relatively little training data. We propose
modeling target motion patterns as a mixture of Gaussian
processes (GP) with a Dirichlet process (DP) prior over
mixture weights. The GP provides a flexible representation
for each individual motion pattern, while the DP assigns observed
trajectories to particular motion patterns. Both automatically
adjust the complexity of the motion model based
on the available data. Our approach outperforms several parametric
models on a helicopter-based car-tracking task on
data collected from the greater Boston area
Promoting influenza prevention for elderly people in Hong Kong using health action process approach: Study protocol
Background: People 65 years or older are at greater risk of serious complications from the seasonal influenza compared with young. To promote elderly people's behavioral compliance toward influenza prevention, the aim of the current project is to develop, implement, and evaluate a theory-based low-administration-cost intervention building on a leading psychological theory, the Health Action Process Approach (HAPA). Methods: The target group is Hong Kong Chinese elderly people aged 65 or older who rarely or never adopt any preventive actions. This project will be conducted in three phases over 24 months. In phase 1, intervention program will be developed building on the HAPA theoretical framework which comprises both the initiation and maintenance of influenza prevention behaviors. In phase 2, intervention will be implemented and evaluated using a randomized controlled trial, including: (a) behavior initiation only, (b) behavior initiation + behavior maintenance, and (c) control group. Both the initiation and maintenance components will comprise weekly-delivered telephone-based individual intervention sessions in 3 months. In phase 3, outcome evaluation of behavioral and psychological variables and process evaluation will be conducted. The effectiveness of the intervention will be analyzed using a series of linear mixed models on each behavioral and psychological outcome variable. Structural equation modelling will be used to test the hypothesized theoretical sequence in the HAPA model. Discussion: The proposed project is expected to design theory-based intervention materials to promote the influenza prevention behaviors in Hong Kong elderly people and provide information on its effectiveness and the potential changing mechanism of behavior initiation and maintenance. Trial registration: This randomized controlled trial was funded by the Health and Medical Research Fund (HMRF), Food and Health Bureau of the Government of the Hong Kong Special Administrative Region (Ref: 16151222) and was registered on 13/10/2017 at CCRB Clinical Trials Registry of the Chinese University of Hong Kong, a Partner Registry of a WHO Primary Registry (Ref: CUHK-CCRB00567)
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