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Labeling Procedure (labeling + procedure)

Distribution by Scientific Domains
Medical Sciences66%
Life Sciences33%

Selected Abstracts

Light and electron microscopic analysis of KChIP and Kv4 localization in rat cerebellar granule cells

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 2 2005
Brian W. Strassle
Abstract Potassium channels are key determinants of neuronal excitability. We recently identified KChIPs as a family of calcium binding proteins that coassociate and colocalize with Kv4 family potassium channels in mammalian brain (An et al. [2000] Nature 403:553). Here, we used light microscopic immunohistochemistry and multilabel immunofluorescence labeling, together with transmission electron microscopic immunohistochemistry, to examine the subcellular distribution of KChIPs and Kv4 channels in adult rat cerebellum. Light microscopic immunohistochemistry was performed on 40-,m free-floating sections using a diaminobenzidine labeling procedure. Multilabel immunofluorescence staining was performed on free-floating sections and on 1-,m ultrathin cryosections. Electron microscopic immunohistochemistry was performed using an immunoperoxidase pre-embedding labeling procedure. By light microscopy, immunoperoxidase labeling showed that Kv4.2, Kv4.3, and KChIPs 1, 3, and 4 (but not KChIP2) were expressed at high levels in cerebellar granule cells (GCs). Kv4.2 and KChIP1 were highly expressed in GCs in rostral cerebellum, whereas Kv4.3 was more highly expressed in GCs in caudal cerebellum. Immunofluorescence labeling revealed that KChIP1 and Kv4.2 are concentrated in somata of cerebellar granule cells and in synaptic glomeruli that surround synaptophysin-positive mossy fiber axon terminals. Electron microscopic analysis revealed that KChIP1 and Kv4.2 immunoreactivity is concentrated along the plasma membrane of cerebellar granule cell somata and dendrites. In synaptic glomeruli, KChIP1 and Kv4.2 immunoreactivity is concentrated along the granule cell dendritic membrane, but is not concentrated at postsynaptic densities. Taken together, these data suggest that A-type potassium channels containing Kv4.2 and KChIP1, and perhaps also KChIP3 and 4, play a critical role in regulating postsynaptic excitability at the cerebellar mossy-fiber/granule cell synapse. J. Comp. Neurol. 484:144,155, 2005. © 2005 Wiley-Liss, Inc. [source]

Positron Emission Tomography in Clinical Islet Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2009
O. Eriksson
The fate of islets in clinical transplantation is unclear. To elude on this positron emission tomography combined with computed tomography (PET/CT) was performed for 60 min during islet transplantation in five patients receiving six transplants. A fraction of the islets (23%) were labeled with 18F-fluorodeoxyglucose ([18F]FDG) and carefully mixed with unlabeled islets just prior to intraportal transplantation. The peak radioactivity concentration in the liver was found at 19 min after start of islet infusion and corresponded to only 75% of what was expected, indicating that islets are lost during the transplantation procedure. No accumulation of radioactivity was found in the lungs. A nonphysiological peak of C-peptide was found in plasma during and immediately after transplantation in all subjects. Distribution in the liver was heterogeneous with wide variations in location and concentration. Islets found in areas with concentrations of >400 IEQ/cc liver tissue varied between 1% and 32% of the graft in different subjects. No side effects attributed to the PET/CT procedure were found. Clinical outcome in all patients was comparable to that previously observed indicating that the [18F]FDG labeling procedure did not harm the islets. The technique has potential to be used to assess approaches to enhance islet survival and engraftment in clinical transplantation. [source]

Improving the Procedure for Detection of Intrahepatic Transplanted Islets by Magnetic Resonance Imaging

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2009
M. L. Malosio
Islet transplantation is an effective therapy for restoring normoglycemia in type-1 diabetes, but long-term islet graft function is achieved only in a minority of cases. Noninvasive magnetic resonance imaging of pancreatic islets is an attractive option for "real-time" monitoring of graft evolution. So far, previous studies have been performed in the absence of a standardized labeling procedure and, besides a feasibility study in patients, the effectiveness and safety of various labeling approaches were tested only with high field magnets (4.7 T). In this study, we addressed: (a) standardization of a labeling procedure for human islets with clinically-approved contrast agent Endorem®, (b) safety aspects of labeling related to inflammation and (c) quality of imaging both at 7 T and 1.5 T. We have highlighted that the ratio of Endorem®/islet is crucial for reproducible labeling, with a ratio of 2.24 ug/IEQ, allowing successful in vivo imaging both with 1.5 T and 7.0 T magnets up to 143 days after intrahepatic transplant. With this standardized labeling procedure, labeled islets are neither inflamed nor more susceptible to inflammatory insults than unlabeled ones. This report represents an important contribution towards the development of a standardized and safe clinical protocol for the noninvasive imaging of transplanted islets in humans. [source]

New tools for labeling silica in living diatoms

NEW PHYTOLOGIST, Issue 3 2008
Julien Desclés
Summary ,,Silicon biomineralization is a widespread mechanism found in several kingdoms that concerns both unicellular and multicellular organisms. As a result of genomic and molecular tools, diatoms have emerged as a good model for biomineralization studies and have provided most of the current knowledge on this process. However, the number of techniques available to study its dynamics at the cellular level is still rather limited. ,,Here, new probes were developed specifically to label the pre-existing or the newly synthesized silica frustule of several diatoms species. ,,It is shown that the LysoTracker Yellow HCK-123, which can be used to visualize silica frustules with common filter sets, presents an enhanced signal-to-noise ratio and allows details of the frustules to be imaged without of the use of ionophores. It is also demonstrated that methoxysilane derivatives can be coupled to fluorescein-5-isothiocyanate (FITC) to preferentially label the silica components of living cells. ,,The coupling of labeling procedures might help to address the challenging question of the process of frustule exocytosis. [source]

Proteomics: Recent Applications and New Technologies

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2006
Mollisa M. Elrick
Proteomic analyses have recently been conducted on tissues, biofluids, subcellular components and enzymatic pathways as well as various disease and toxicological states, in both animal models and man. In addition, several recent studies have attempted to integrate proteomics data with genomics and/or metabonomics data in a systems biology approach. The translation of proteomic technology and bioinformatics tools to clinical samples, such as in the areas of disease and toxicity biomarkers, represents one of the major opportunities and challenges facing this field. An ongoing challenge in proteomics continues to be the analysis of the serum proteome due to the vast number and complexity of proteins estimated to be present in this biofluid. Aside from the removal of the most abundant proteins, a number of interesting approaches have recently been suggested that may help reduce the overall complexity of serum analysis. In keeping with the increasing interest in applications of proteomics, the tools available for proteomic analyses continue to improve and expand. For example, enhanced tools (such as software and labeling procedures) continue to be developed for the analysis of 2D gels and protein quantification. In addition, activity-based probes are now being used to tag, enrich and isolate distinct sets of proteins based on enzymatic activity. One of the most active areas of development involves microarrays. Antibody-based microarrays have recently been released as commercial products while numerous additional capture agents (e.g. aptamers) and many additional types of microarrays are being explored. [source]