scholarly journals Assessment of Human Pancreatic Islet Architecture and Composition by Laser Scanning Confocal Microscopy

2005 ◽  
Vol 53 (9) ◽  
pp. 1087-1097 ◽  
Author(s):  
Marcela Brissova ◽  
Michael J. Fowler ◽  
Wendell E. Nicholson ◽  
Anita Chu ◽  
Boaz Hirshberg ◽  
...  
Keyword(s):  
Pancreatic Islet ◽  
Laser Scanning ◽  
Cell Types ◽  
Human Islets ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Human Pancreas ◽  
Pancreatic Islet Transplantation ◽  
Histological Sections ◽  
Human Primate

The recent success of pancreatic islet transplantation has generated considerable enthusiasm. To better understand the quality and characteristics of human islets used for transplantation, we performed detailed analysis of islet architecture and composition using confocal laser scanning microscopy. Human islets from six separate isolations provided by three different islet isolation centers were compared with isolated mouse and non-human primate islets. As expected from histological sections of murine pancreas, in isolated murine islets α and δ cells resided at the periphery of the β-cell core. However, human islets were markedly different in that α, β, and δ cells were dispersed throughout the islet. This pattern of cell distribution was present in all human islet preparations and islets of various sizes and was also seen in histological sections of human pancreas. The architecture of isolated non-human primate islets was very similar to that of human islets. Using an image analysis program, we calculated the volume of α, β, and δ cells. In contrast to murine islets, we found that populations of islet cell types varied considerably in human islets. The results indicate that human islets not only are quite heterogeneous in terms of cell composition but also have a substantially different architecture from widely studied murine islets.

Sterols and lignin in Eucalyptus globulus Labill. wood: Spatial distribution and fungal removal as revealed by microscopy and chemical analyses

Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Mariela Speranza ◽  
Ana Gutiérrez ◽  
José Carlos del Río ◽  
Lina Bettucci ◽  
Ángel T. Martínez ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Laser Scanning ◽  
Cell Types ◽  
Laser Scanning Microscopy ◽  
Gas Chromatography Mass Spectrometry ◽  
Confocal Laser ◽  
Lipophilic Compounds ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells

AbstractWood decay experiments were carried out aiming at the selective removal of lipophilic compounds with selected basidiomycetes isolated fromEucalyptus globulusplantations in Uruguay:Dendrophora albobadia,Lentinus tigrinus,Peniophora cinerea,Peniophora lycii, andPhanerochaete crassa. Localization and composition of lipophilic compounds and lignin ofE. globuluswere determined by gas chromatography-mass spectrometry, fluorescence microscopy using filipin staining, confocal laser scanning microscopy (CLSM), and low temperature scanning electron microscopy. Free and esterified sterols, mainly sitosterol, were the predominant lipophilic compounds in the control wood. Sterols were present in ray parenchyma cells, together with polyphenols, and in vessels. This confirms earlier observations indicating that these cell types are the principal source of lipophilic extractives involved in pitch problems during pulping and bleaching. Sterols are also present in the vestures of fiber and vessel pits. Different fungal degradation patterns ofE. globuluswood were determined.P. lyciishowed the highest specificity for lignin degradation during short incubation time together with considerable sterol removal capacity. Ray parenchyma cells and their lumen deposits were strongly degraded byP. lycii. Eucalypt lignin located in vessel walls and fiber cell corners was more resistant to fungal attack, as revealed by CLSM. The initial decay stage ofL. tigrinuswas restricted to vessels and tyloses where the sterol compounds were removed.

scholarly journals Uptake of the proteins HTRA1 and HTRA2 by cells mediated by calcium phosphate nanoparticles

2017 ◽  
Vol 8 ◽  
pp. 381-393 ◽  
Author(s):  
Olga Rotan ◽  
Katharina N Severin ◽  
Simon Pöpsel ◽  
Alexander Peetsch ◽  
Melisa Merdanovic ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Cell Membrane ◽  
Laser Scanning ◽  
Cell Types ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Synthetic Drugs ◽  
Uptake Pathway ◽  
Calcium Phosphate Nanoparticles ◽  
Dissolved Form

The efficient intracellular delivery of (bio)molecules into living cells remains a challenge in biomedicine. Many biomolecules and synthetic drugs are not able to cross the cell membrane, which is a problem if an intracellular mode of action is desired, for example, with a nuclear receptor. Calcium phosphate nanoparticles can serve as carriers for small and large biomolecules as well as for synthetic compounds. The nanoparticles were prepared and colloidally stabilized with either polyethyleneimine (PEI; cationic nanoparticles) or carboxymethyl cellulose (CMC; anionic nanoparticles) and loaded with defined amounts of the fluorescently labelled proteins HTRA1, HTRA2, and BSA. The nanoparticles were purified by ultracentrifugation and characterized by dynamic light scattering and scanning electron microscopy. Various cell types (HeLa, MG-63, THP-1, and hMSC) were incubated with fluorescently labelled proteins alone or with protein-loaded cationic and anionic nanoparticles. The cellular uptake was followed by light and fluorescence microscopy, confocal laser scanning microscopy (CLSM), and flow cytometry. All proteins were readily transported into the cells by cationic calcium phosphate nanoparticles. Notably, only HTRA1 was able to penetrate the cell membrane of MG-63 cells in dissolved form. However, the application of endocytosis inhibitors revealed that the uptake pathway was different for dissolved HTRA1 and HTRA1-loaded nanoparticles.

scholarly journals Morphometric studies of the localization of the glucocorticoid receptor in mammalian cells and of glucocorticoid hormone-induced effects.

1994 ◽  
Vol 42 (5) ◽  
pp. 645-657 ◽  
Author(s):  
G Akner ◽  
A C Wikström ◽  
K Mossberg ◽  
K G Sundqvist ◽  
J A Gustafsson
Keyword(s):  
Glucocorticoid Receptor ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Nuclear Translocation ◽  
Cell Types ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Mitotic Apparatus ◽  
Glucocorticoid Treatment ◽  
Cytoplasmic Microtubules

We studied the subcellular distribution of the glucocorticoid receptor (GR) by light microscopy (LM) and confocal laser scanning microscopy (CLSM) in different mammalian cell types. The effect of added glucocorticoid hormones on GR distribution was investigated by photometric quantitation on optical sections obtained by CLSM followed by statistical analysis. In the control interphase cytoplasm, the distribution of GR was fibrillar in some and diffuse in other cell types. Fibrillar GR was distributed along cytoplasmic microtubules (MTs) with predilection for a subset of MTs. GR was also observed in the centrosomes. Nuclear GR was both diffuse and granular in distribution. During cell division, GR appeared in the mitotic apparatus at all stages of mitosis. These findings were not fixation-dependent. Glucocorticoid treatment increased both the nuclear and cytoplasmic GR signal. However, this was detectable only after precipitating but not cross-linking fixation. There was both intra- and intercellular GR heterogeneity in the absence and presence of hormone but no indication of a hormone-induced nuclear translocation of GR. We present a hypothetical model of two independent GR populations in the nucleus and cytoplasm, respectively, without any discernible ligand-induced nuclear translocation of GR. The extranuclear GR population may exert effect(s) on site in the cytoplasm without involving nuclear genomic transcription.

scholarly journals Microscopic and Spectroscopic Analyses of Chlorhexidine Tolerance in Delftia acidovorans Biofilms

2014 ◽  
Vol 58 (10) ◽  
pp. 5673-5686 ◽  
Author(s):  
Tara Rema ◽  
John R. Lawrence ◽  
James J. Dynes ◽  
Adam P. Hitchcock ◽  
Darren R. Korber
Keyword(s):  
Laser Scanning ◽  
Cell Types ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Content Type ◽  
Flow Cells ◽  
Biofilm Thickness ◽  
Delftia Acidovorans ◽  
Scanning Transmission ◽  
Negative Effect

ABSTRACTThe physicochemical responses ofDelftia acidovoransbiofilms exposed to the commonly used antimicrobial chlorhexidine (CHX) were examined in this study. A CHX-sensitive mutant (MIC, 1.0 μg ml−1) was derived from a CHX-tolerant (MIC, 15.0 μg ml−1)D. acidovoransparent strain using transposon mutagenesis.D. acidovoransmutant (MT51) and wild-type (WT15) strain biofilms were cultivated in flow cells and then treated with CHX at sub-MIC and inhibitory concentrations and examined by confocal laser scanning microscopy (CLSM), scanning transmission X-ray microscopy (STXM), and infrared (IR) spectroscopy. Specific morphological, structural, and chemical compositional differences between the CHX-treated and -untreated biofilms of both strains were observed. Apart from architectural differences, CLSM revealed a negative effect of CHX on biofilm thickness in the CHX-sensitive MT51 biofilms relative to those of the WT15 strain. STXM analyses showed that the WT15 biofilms contained two morphochemical cell variants, whereas only one type was detected in the MT51 biofilms. The cells in the MT51 biofilms bioaccumulated CHX to a similar extent as one of the cell types found in the WT15 biofilms, whereas the other cell type in the WT15 biofilms did not bioaccumulate CHX. STXM and IR spectral analyses revealed that CHX-sensitive MT51 cells accumulated the highest levels of CHX. Pretreating biofilms with EDTA promoted the accumulation of CHX in all cells. Thus, it is suggested that a subpopulation of cells that do not accumulate CHX appear to be responsible for greater CHX resistance inD. acidovoransWT15 biofilm in conjunction with the possible involvement of bacterial membrane stability.

scholarly journals Direct fluorescence imaging of lignocellulosic and suberized cell walls in roots and stems

AoB Plants ◽  
2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Peter Kitin ◽  
Satoshi Nakaba ◽  
Christopher G Hunt ◽  
Sierin Lim ◽  
Ryo Funada
Keyword(s):  
Cell Walls ◽  
Laser Scanning ◽  
Cell Types ◽  
Plant Evolution ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Chemical Information ◽  
Wide Field ◽  
Tissue Preparation ◽  
Plant Structure

Abstract Investigating plant structure is fundamental in botanical science and provides crucial knowledge for the theories of plant evolution, ecophysiology and for the biotechnological practices. Modern plant anatomy often targets the formation, localization and characterization of cellulosic, lignified or suberized cell walls. While classical methods developed in the 1960s are still popular, recent innovations in tissue preparation, fluorescence staining and microscopy equipment offer advantages to the traditional practices for investigation of the complex lignocellulosic walls. Our goal is to enhance the productivity and quality of microscopy work by focusing on quick and cost-effective preparation of thick sections or plant specimen surfaces and efficient use of direct fluorescent stains. We discuss popular histochemical microscopy techniques for visualization of cell walls, such as autofluorescence or staining with calcofluor, Congo red (CR), fluorol yellow (FY) and safranin, and provide detailed descriptions of our own approaches and protocols. Autofluorescence of lignin in combination with CR and FY staining can clearly differentiate between lignified, suberized and unlignified cell walls in root and stem tissues. Glycerol can serve as an effective clearing medium as well as the carrier of FY for staining of suberin and lipids allowing for observation of thick histological preparations. Three-dimensional (3D) imaging of all cell types together with chemical information by wide-field fluorescence or confocal laser scanning microscopy (CLSM) was achieved.

Contraction of Collagen Lattices by Cells from Dupuytren’s Nodules

1996 ◽  
Vol 21 (6) ◽  
pp. 801-805 ◽  
Author(s):  
E. TARPILA ◽  
M. R. GHASSEMIFAR ◽  
S. WINGREN ◽  
M. ÅGREN ◽  
L. FRANZÉN
Keyword(s):  
Laser Scanning ◽  
Cell Types ◽  
Dermal Fibroblasts ◽  
Laser Scanning Microscopy ◽  
Platelet Derived Growth Factor ◽  
Dupuytren’S Disease ◽  
Confocal Laser ◽  
Dupuytren's Disease ◽  
Dermal Cells ◽  
Collagen Lattices

The aim of this study was to see if nodular cells in Dupuytren’s disease differed from dermal cells in their contractile capacity and motility. Ten surgical specimens from patients with Dupuytren’s disease and contracture of the finger of more than 45° were harvested and the nodular cells were explanted and cultured. Dermal fibroblasts from the forearm were used as control cells. Both types of cell had the same growth pattern. The morphology on confocal laser scanning microscopy was also similar in both types of cell. Dermal control cells caused significantly more contraction of collagen lattices compared with fibroblasts from nodules of Dupuytren’s contracture. The F-actin content was equal in both groups. Platelet derived growth factor, PDGF-BB (but not PDGF-AA), increased the chemotactic activity of both cell types, but there were no differences between them. The results indicate that at a late state of the disease cells from Dupuytren’s nodules lose their contractile capacity and regain a phenotype resembling that of dermal fibroblasts.

scholarly journals Expression and immunolocalization of the calpain–calpastatin system during parthenogenetic activation and fertilization in the rat egg

Reproduction ◽  
2006 ◽  
Vol 131 (1) ◽  
pp. 35-43 ◽  
Author(s):  
K Haim ◽  
I Ben-Aharon ◽  
R Shalgi
Keyword(s):  
Laser Scanning ◽  
Cell Types ◽  
Laser Scanning Microscopy ◽  
Meiotic Spindle ◽  
Tissue Type ◽  
Egg Activation ◽  
Confocal Laser ◽  
Membrane Area ◽  
Rat Eggs ◽  
And Function

Calpastatin is an intrinsic intracellular inhibitor of calpain, a Ca2+-dependent thiol protease. The calpain–calpastatin system constitutes one functional proteolytic unit whose presence and function has already been investigated in various cell types, but not in the egg. We have previously shown that calpain is expressed in rat eggs and is activated upon egg activation. The present study was designed to investigate the calpain–calpastatin interplay throughout the process.Western blot analysis revealed two main calpastatin isoforms, the erythrocyte type (77 kDa) and the muscle tissue type (110 kDa). By immunohistochemistry and confocal laser scanning microscopy, we demonstrated that the 110 kDa calpastatin was localized at the membrane area and highly abundant at the meiotic spindle in eggs at the first and second meiotic divisions. The 77 kDa calpastatin isoform appeared to be localized as a cortical sphere of clusters. The 110kDa calpastatin and β-tubulin have both been localized to the spindle of metaphase II eggs, both being scattered all through the cytoplasm following spindle disruption by nocodazole treatment, implying a dynamic interaction between calpastatin and microtubule elements. Upon egg activation, membranous calpastatin translocated to the cortex whereas cortical millimolar (m)-calpain shifted towards the membrane. Spindle calpastatin and calpain remained static.We suggest that calpastatin serves as a regulator of m-calpain. The counter translocation of m-calpain and calpastatin could serve as a means of calpain escape from calpastatin inhibition and may reflect a step in the process of calpain activation, throughout egg activation, that is required for calpain to exert its proteolytic activity.

scholarly journals Active and inactive genes localize preferentially in the periphery of chromosome territories.

1996 ◽  
Vol 135 (5) ◽  
pp. 1195-1205 ◽  
Author(s):  
A Kurz ◽  
S Lampel ◽  
J E Nickolenko ◽  
J Bradl ◽  
A Benner ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Cell Types ◽  
Chromosome Territory ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Chromosome Territories ◽  
Inactive Genes ◽  
Different Cell Types ◽  
The Impact

The intranuclear position of a set of genes was analyzed with respect to the territories occupied by the whole chromosomes in which these genes are localized. Genes and their respective chromosome territories were simultaneously visualized in three-dimensionally preserved nuclei applying dual color fluorescence in situ hybridization. Three coding (DMD, MYH7, and HBB) and two noncoding sequences (D1Z2 and an anonymous sequence) were analyzed in four different cell types, including cells where DMD and MYH7 are actively transcribed. Spatial analysis by confocal laser scanning microscopy revealed that the genes are preferentially located in the periphery of chromosome territories. This positioning was independent from the activity of the genes. In contrast, the non-expressed anonymous fragment was found randomly distributed or localized preferentially in the interior of the corresponding chromosome territory. Furthermore, the distribution of the analyzed genes within the territorial peripheries was found to be highly characteristic for each gene, and, again, independent from its expression. The impact of these findings with regard to the three-dimensional arrangement of the linear DNA string within chromosome territories, as well as with respect to a putative nuclear subcompartment confining gene expression, are discussed.

Use of Biocytin as Neuroanatomic Tracer in Harvested Human Pancreas: A Confocal Laser Scanning Microscopy Analysis

Pancreas ◽  
2002 ◽  
Vol 24 (4) ◽  
pp. 329-335
Author(s):  
Saturnino Spiga ◽  
Liana Fattore ◽  
Maria Cristina Puddu ◽  
Antonello Cappai ◽  
Susanna Picciau ◽  
...  
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Human Pancreas ◽  
Microscopy Analysis
Sign in / Sign up

Export Citation Format

Share Document