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Compact Structure (compact + structure)
Selected AbstractsInfluence of carbohydrates on stability of papain in aqueous tetrahydrofuran mixtureJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2009András Szabó Abstract BACKGROUND: The use of enzymes in organic solvents has extended the scale of their practical applications. Papain has been widely used in chemical syntheses because of its broad substrate specificity. The aim of the present study was to improve the stability of papain in aqueous tetrahydrofuran (THF) by using different saccharides. The effects of these carbohydrates on the structure of papain were followed by means of circular dichroism (CD) and fluorescence spectroscopic measurements. RESULTS: In contrast with most organic solvents, 60% (i.e. 600 mL L,1) THF practically inactivated the enzyme within 30 min. Sugars protected papain from THF-induced inactivation in the sequence D -ribose > D -fructose > D -glucose > D -saccharose > D -raffinose. Ribose at 1.6 mol L,1 proved the most effective stabiliser: in 60% THF in the presence of ribose, papain preserved about 55% of its initial activity after 2 h. Fluorescence and near-UV CD spectroscopic measurements revealed local changes in the papain conformation. With decrease in the free amino group content of the enzyme, protein-carbohydrate interactions (Schiff base formation) were detected. CONCLUSION: These results demonstrate that the catalytic activity and stability of papain may be increased in aqueous THF by using different carbohydrates, when a more compact structure of the enzyme is formed. Copyright © 2008 Society of Chemical Industry [source] Protein Hydrolysate of Salted Duck Egg White as a Substitute of Phosphate and Its Effect on Quality of Pacific White Shrimp (Litopenaeus Vannamei)JOURNAL OF FOOD SCIENCE, Issue 8 2009Thammarat Kaewmanee ABSTRACT:, Protein hydrolysate from salted egg white (PHSEW) with different degrees of hydrolysis (DH) (3%, 6%, and 9%) was produced using pepsin. Disappearance of proteins with molecular weight (MW) of 108 and 85 kDa with the concomitant formation of proteins with MW of 23, 20, 13, and 5 kDa was observed in PHSEW. The use of PHSEW for quality improvement of Pacific white shrimp (Litopenaeus vannamei) was investigated. Shrimp soaked in 4% NaCl containing 7% PHSEW and 2.5% mixed phosphates (0.625% sodium acid pyrophosphate [SAPP] and 1.875% tetrasodium pyrophosphate [TSPP]) had the highest cooking yield with the lowest cooking loss (P,< 0.05), compared with shrimps with other treatments. Nevertheless, no difference in weight gain was obtained in comparison with those treated with 4% NaCl containing 3.5% mixed phosphate (P,> 0.05). Cooked shrimp treated with 4% NaCl containing 7% PHSEW and 2.5% mixed phosphate or those treated with 4% NaCl containing 3.5% mixed phosphate had the higher score of appearance, texture, and overall likeness but less shear force, in comparison with the control (no treatment) (P,< 0.05). Microstructure study revealed that muscle fibers of cooked shrimp from both treatments had the swollen fibrils and gaps, while the control had the swollen compact structure. Therefore, use of PHSEW could reduce phosphate residue in shrimps without an adverse effect on sensory properties. [source] The structure of the outer shell layer in radiolitid rudists, a morphoconstructional approachLETHAIA, Issue 3 2008JOSE MARIA PONS Radiolitids (Bivalvia, Radiolitidae) built the calcite outer layer of their shell with compact structure as many other bivalves, or with repetitively layered non-compact structure following different patterns: continuous radial ridges, discontinuous radial ridges, normal cellular, cellular with radially elongate cells, discontinuous cellular, and discontinuous cellular with elongate cells. Some special structures may develop in localized parts: radial structures and inner-marginal or radial grooves. All these structures are currently used in the diagnosis of the family and for the characterization of subfamilies. Constructional morphology analyses and re-evaluation of all these structures reveal that they were misunderstood in some important aspects in the bivalve Treatise and that, consequently, the diagnosis of the family has to be emended and their subfamilies reconsidered. All outer shell layer structure related characters are described, illustrated, and interpreted under a constructional approach, some characters are proposed to emend the diagnosis of the family, and two possible clades are preliminarily distinguished. [source] Solution Behavior of Temperature-Responsive Molecular Brushes Prepared by ATRPMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 1 2007Joanna Pietrasik Abstract Molecular brushes, with side chains consisting of two copolymers: 2-(dimethylamino)ethyl methacrylate with methyl methacrylate, and N,N -dimethylacrylamide with butyl acrylate were prepared by grafting-from via atom transfer radical polymerization (ATRP). Poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) and poly(2-(2-bromopropionyloxy)ethyl methacrylate) were used as macroinitiators. Dynamic light scattering (DLS) studies were performed for aqueous solutions of molecular brushes below and above the lower critical solution temperature (LCST), and an unusual concentration-dependent LCST was observed. Due to the compact structure of molecular brushes, intramolecular collapse can occur when the average distance between molecules is much larger than the hydrodynamic dimensions of the individual macromolecules. However, if the concentration of the solution of molecular brushes is increased to the level in which the separation distance is comparable with the brush hydrodynamic dimensions, intermolecular aggregation occurs, as typically observed for solutions of linear polymers. [source] On/off switching on polymer conformationMACROMOLECULAR SYMPOSIA, Issue 1 2003Kenichi Yoshikawa Abstract The manner of folding transition from elongated coil to compact globule of single polymer chain is discussed. Based on theoretical consideration, it is argued the semi-flexible polymer chain exhibits large discrete transition on the level of individual single chains, whereas the transition looks continuous, or cooperative, on the ensemble of chains. As the experimental verification, in the present article thermodynamic and kinetic aspects of folding transition of single giant DNA molecules are described. It is shown that rich variety of nano-ordered structures are obtained from single DNA molecules through suitable setup of the experimental conditions. The stability of such nano-structures generated from single polymer chain is discussed in relation to the ordered compact structure with large number of chains in semi-dilute and concentrated polymer solutions. [source] Compact high-gain printed loop-antenna array integrated into a 5-GHz WLAN access pointMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010Tzi-Chieh Hong Abstract A printed, planar loop-antenna array having a compact structure and high-gain, directional radiation properties for WLAN operation in the 5 GHz band is presented. The antenna-array design is composed of four-folded loops arranged to be of 2 × 2 configuration, printed on both sides of a 1.6-mm thick FR4 substrate, and one system printed circuit board (PCB) serving as an efficient reflector for the loops. The antenna array is set within the boundary of the PCB (size of 50 mm ×65 mm) and stacked there above by a separation distance of 5.4 mm only. That's, the design integrates the system PCB of an access point (AP) into an internal antenna solution for compact outdoor AP applications. The results show that good input matching with voltage standing wave ratio (VSWR) below 1.5 over the 5150,5825 MHz band can be achieved. Directional radiation patterns with peak gain at about 10 dBi were also obtained. Details of the antenna design are described and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2261,2267, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25487 [source] Seven-band folded-loop chip antenna for WWAN/WLAN/WiMAX operation in the mobile phoneMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009Ming-Ren Hsu Abstract A chip antenna formed by using an FR4 chip base and a folded-loop metal pattern embedded therein for internal mobile phone antenna application is presented. The folded-loop metal pattern is embedded in two different layers inside the FR4 chip base to achieve a compact structure, and a coupling gap is introduced to successfully excite two wide operating bands at about 900 and 2000 MHz to cover GSM850/900/1800/1900/UMTS, 2.4-GHz WLAN, and 2.5-GHz WiMAX operations; that is, a seven-band internal mobile phone antenna for covering WWAN/WLAN/WiMAX operation is obtained. The proposed chip antenna also occupies a small volume of 4 × 5 × 40 mm3 (0.8 cm3) and shows a low profile of 5 mm when mounted on the system circuit board of the mobile phone, making it suitable for thin mobile phone applications. The proposed chip antenna is studied and tested. The SAR effect of the antenna is also analyzed in the study. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 543,549, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24063 [source] Uniplanar coupled-fed printed PIFA for WWAN operation in the laptop computerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009Kin-Lu Wong Abstract In this article, a uniplanar printed PIFA (planar inverted-F antenna) with a coupling feed for application as an internal laptop computer antenna for penta-band WWAN (wireless wide area network) operation is presented. The proposed PIFA has a compact structure and can be easily printed on one side of a small 0.8-mm thick FR4 substrate of size 11 × 59 mm2, making it very promising to be embedded inside the casing of the laptop computer, especially for the thin-profile laptop computer. With the coplanar coupling feed, the large inductive input reactance of the PIFA at around 900 MHz is compensated, and dual-resonance excitation for the antenna's lower band at about 900 MHz is obtained, which allows it to easily cover GSM850/900 operation. A wide operating band is also achieved for the antenna's upper band at about 1900 MHz, and a bandwidth of larger than 500 MHz is obtained to cover GSM1800/1900/UMTS operation. That is, the proposed PIFA covers all the five operating bands of GSM850/900/1800/1900/UMTS for WWAN operation. Details of the proposed PIFA are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 549,554, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24084 [source] Compact coaxial-line-fed flat-plate dipole antenna for WLAN applicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008Saou-Wen Su Abstract A novel coaxial-line-fed flat-plate dipole antenna for WLAN operation in the 2.4 GHz band is presented. The dipole antenna is rectangular in shape and can easily be fabricated by stamping a metal plate at low cost. The two radiating arms of the dipole antenna are first bent into a compact structure with the dimensions 10 mm × 38 mm and further short-circuited with a narrow shorting strip, which allows the antenna to be obtained from one single, stamped metal plate only. In addition, good impedance matching for 2.4 GHz operation can also be achieved by controlling the distance between the feeding points and the shorting strip. The design prototype of the antenna is elaborated and discussed in detail in the article. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 420,422, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23116 [source] Compact LTCC bandpass filter design with controllable transmission zeros in the stopbandMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2006Jianhua Deng Abstract Method of designing a modified Chebyshev bandpass filter with controllable transmission zeros in the stopband is described. A novel compact structure of this kind of filter with a transmission zero located at higher stopband for LTCC implementation is proposed. The filter has promising potential applications in miniaturized wireless communication systems. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1919,1922, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21814 [source] Quad-band internal monopole mobile-phone antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2004Gwo-Yun Lee Abstract A novel internal monopole antenna suitable for applications in AMPS/GSM/DCS/PCS quad-band mobile phones is presented. The antenna comprises two orthogonal wideband monopole elements for operation at about 900 and 1850 MHz, covering the APMS/GSM (824,894/890,960 MHz) and DCS/PCS (1710,1880/1850,1990 MHz) bands, respectively. The quad-band monopole antenna is also arranged in a compact structure such that it has a low profile (only 6 mm in this study) and protrudes from the top edge of the system ground plane of a communications device, thus making it very promising as an internal antenna, built-in within the device's casing. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 359,361, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11381 [source] Hydrogen-bonding interaction of an alternating maleic acid,vinyl acetate copolymer with poly(ethylene glycol), polyacrylamide and poly(N -isopropylacrylamide): a comparative studyPOLYMER INTERNATIONAL, Issue 12 2003C Vasile Abstract The hydrogen-bonding interaction and interpolymer complex formation between an alternating maleic acid,vinyl acetate copolymer, (MAc- alt -VA) and poly(ethylene glycol) (PEG), polyacrylamide (PAM) or poly(N -isopropylacrylamide) (PNIPAM) in aqueous solution was potentiometrically and viscometrically investigated. MAc- alt -VA formed with PEG a strong hydrogen-bonding interpolymer complex with a compact structure, and while its interaction with PAM seems to be very weak, if any, the complex formed with PNIPAM is even stronger than that with PEG. This indicates a very important contribution of hydrophobic interaction to the formation of such hydrogen-bonding interpolymer complexes. Copyright © 2003 Society of Chemical Industry [source] The disulfide bond pattern of catrocollastatin C, a disintegrin-like/cysteine-rich protein isolated from Crotalus atrox venomPROTEIN SCIENCE, Issue 7 2000Juan J. Calvete Abstract The disulfide bond pattern of catrocollastatin-C was determined by N-terminal sequencing and mass spectrometry. The N-terminal disintegrin-like domain is a compact structure including eight disulfide bonds, seven of them in the same pattern as the disintegrin bitistatin. The protein has two extra cysteine residues (XIII and XVI) that form an additional disulfide bond that is characteristically found in the disintegrin-like domains of cellular metalloproteinases (ADAMs) and PIII snake venom Zn-metalloproteinases (SVMPs). The C-terminal cysteine-rich domain of catrocollastatin-C contains five disulfide bonds between nearest-neighbor cysteines and a long range disulfide bridge between CysV and CysX. These results provide structural evidence for a redefinition of the disintegrin-like and cysteine-rich domain boundaries. An evolutionary pathway for ADAMs, PIII, and PII SVMPs based on disulfide bond engineering is also proposed. [source] Thermal denaturation pathway of starch phosphorylase from Corynebacterium callunae: Oxyanion binding provides the glue that efficiently stabilizes the dimer structure of the proteinPROTEIN SCIENCE, Issue 6 2000Richard GrießLer Abstract Starch phosphorylase from Corynebacterium callunae is a dimeric protein in which each mol of 90 kDa subunit contains 1 mol pyridoxal 5,-phosphate as an active-site cofactor. To determine the mechanism by which phosphate or sulfate ions bring about a greater than 500-fold stabilization against irreversible inactivation at elevated temperatures (,50°C), enzyme/oxyanion interactions and their role during thermal denaturation of phosphorylase have been studied. By binding to a protein site distinguishable from the catalytic site with dissociation constants of Ksulfate = 4.5 mM and Kphosphate,16 mM, dianionic oxyanions induce formation of a more compact structure of phosphorylase, manifested by (a) an increase by about 5% in the relative composition of the ,-helical secondary structure, (b) reduced 1H/2H exchange, and (c) protection of a cofactor fluorescence against quenching by iodide. Irreversible loss of enzyme activity is triggered by the release into solution of pyridoxal 5,-phosphate, and results from subsequent intermolecular aggregation driven by hydrophobic interactions between phosphorylase subunits that display a temperature-dependent degree of melting of secondary structure. By specifically increasing the stability of the dimer structure of phosphorylase (probably due to tightened intersubunit contacts), phosphate, and sulfate, this indirectly (1) preserves a functional active site up to, 50°C, and (2) stabilizes the covalent protein cofactor linkage up to , 70°C. The effect on thermostability shows a sigmoidal and saturatable dependence on the concentration of phosphate, with an apparent binding constant at 50°C of , 25 mM. The extra stability conferred by oxyanion-ligand binding to starch phosphorylase is expressed as a dramatic shift of the entire denaturation pathway to a , 20°C higher value on the temperature scale. [source] Structure of a new crystal form of tetraubiquitinACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2001Cynthia L. Phillips Polyubiquitin chains, in which the C-terminus and a lysine side chain of successive ubiquitin molecules are linked by an isopeptide bond, function to target substrate proteins for degradation by the 26S proteasome. Chains of at least four ubiquitin moieties appear to be required for efficient recognition by the 26S proteasome, although the conformations of the polyubiquitin chains recognized by the proteasome or by other enzymes involved in ubiquitin metabolism are currently unknown. A new crystal form of tetraubiquitin, which has two possible chain connectivities that are indistinguishable in the crystal, is reported. In one possible connectivity, the tetraubiquitin chain is extended and packs closely against the antiparallel neighbor chain in the crystal to conceal a hydrophobic surface implicated in 26S proteasome recognition. In the second possibility, the tetraubiqutitin forms a closed compact structure, in which that same hydrophobic surface is buried. Both of these conformations are quite unlike the structure of tetraubiquitin that was previously determined in a different crystal form [Cook et al. (1994), J. Mol. Biol.236, 601,609]. The new structure suggests that polyubiquitin chains may possess a substantially greater degree of conformational flexibility than has previously been appreciated. [source] Redox Activity and Structural Transition of Heptyl Viologen Adlayers on Cu(100),CHEMPHYSCHEM, Issue 7 2010Min Jiang Dr. Abstract The redox behaviour and potential-dependent adsorption structure of heptyl viologen (1,1,-diheptyl-4,4,-bipyridinium dichloride, DHV2+) on a Cu(100) electrode was investigated in a chloride-containing electrolyte solution by cyclic voltammetry (CV) and in situ electrochemical scanning tunneling microscopy (EC,STM). The dicationic DHV molecules generate a few pairs of current waves in CV measurements which are ascribed to two typical one-electron transfer steps. STM images obtained in a KCl-containing electrolyte solution disclose a well-ordered c(2×2) chloride adlayer on a Cu(100) electrode surface. After injecting DHV2+ molecules into the KCl electrolyte solution, a highly ordered 2D "dot-array" structure in STM images emerges on the c(2×2)-Cl modified Cu(100) electrode surface. DHV2+ molecules spontaneously arrange themselves with their molecular planes facing the electrode surface and their long molecular axis parallel to the step edge. Such adsorption structure can be described by mirror domains and rotational domains which stably exist between 200 mV and ,100 mV. One-electron reduction of the dications DHV2+ around ,150 mV causes a phase transition from a ,dot-array' assembly to a stripe pattern formed by DHV.+ radical monocations in STM images which has a bilayer structure. With a further decrease of the applied electrode potential, the structure of the DHV.+ adlayer undergoes a change from a loose stripe phase to a more compact stripe phase, a subsequent decay of the compact structure, and finally the formation of a new dimer phase. A further electron transfer reaction at ,400 mV causes the formation of an amorphous phase on the chloride free electrode surface. In a reverse anodic sweep, the reproduction of the ordered DHV.+ stacking phase occurs again on top of the chloride lattice. [source] Applications of time-resolved resonance energy transfer measurements in studies of the molecular crowding effect,JOURNAL OF MOLECULAR RECOGNITION, Issue 5 2004Varda Ittah Abstract The native structures of many globular proteins are only weakly stabilized and form in solution ensembles of multiple conformers. The energy differences between the conformers are assumed to be small. This is the case of flexible multidomain proteins where domain motions were observed. High concentrations of inert macrosolute, which create a crowded or confined environment, can cause shifts of the distribution of the conformers of such proteins towards the more compact structures. This effect may also promote compact structures in partially folded proteins. Time-resolved dynamic non-radiative excitation energy transfer (tr-RET) is suitable for detection of either subtle or major changes in distributions of intramolecular distances in protein molecules in solutions. Two experiments were performed which demonstrated the applicability of tr-RET for detection of the effect of macrosolutes on the conformational ensembles of flexible states of protein molecules. The distribution of distances between residues 203 and 169 in the CORE domain of E. coli adenylate kinase (AK) in the denatured state was determined in the presence of high concentrations of dextran 40. A significant shift of the mean of the distribution was observed without reduction of its width. This was interpreted as a shift to compact structure without change of the degree of disorder of the chain. In a second experiment the distribution of the distance between residues 55 and 169 in AK, which spans the cleft between the CORE and the AMPbind domains, was monitored. No clear effect of high concentrations of dextran 40 was found. These experiments show the strength of the application of tr-RET in investigation of changes in the sub-states of flexible conformations of globular protein. Networks of pairs of labeled sites can be prepared and tr-RET experiments can be performed in order to search for the segments of the protein molecules, which respond to the presence of inert macromolecules in their environment. Copyright © 2004 John Wiley & Sons, Ltd. [source] The sequence TGAAKAVALVL from glyceraldehyde-3-phosphate dehydrogenase displays structural ambivalence and interconverts between ,-helical and ,-hairpin conformations mediated by collapsed conformational statesJOURNAL OF PEPTIDE SCIENCE, Issue 5 2007Sunita Patel Abstract The peptide TGAAKAVALVL from glyceraldehyde-3-phosphate dehydrogenase adopts a helical conformation in the crystal structure and is a site for two hydrated helical segments, which are thought to be helical folding intermediates. Overlapping sequences of four to five residues from the peptide, sample both helical and strand conformations in known protein structures, which are dissimilar to glyceraldehyde-3-phosphate dehydrogenase suggesting that the peptide may have a structural ambivalence. Molecular dynamics simulations of the peptide sequence performed for a total simulation time of 1.2 µs, starting from the various initial conformations using GROMOS96 force field under NVT conditions, show that the peptide samples a large number of conformational forms with transitions from ,-helix to ,-hairpin and vice versa. The peptide, therefore, displays a structural ambivalence. The mechanism from ,-helix to ,-hairpin transition and vice versa reveals that the compact bends and turns conformational forms mediate such conformational transitions. These compact structures including helices and hairpins have similar hydrophobic radius of gyration (Rgh) values suggesting that similar hydrophobic interactions govern these conformational forms. The distribution of conformational energies is Gaussian with helix sampling lowest energy followed by the hairpins and coil. The lowest potential energy of the full helix may enable the peptide to take up helical conformation in the crystal structure of the glyceraldehyde-3-phosphate dehydrogenase, even though the peptide has a preference for hairpin too. The relevance of folding and unfolding events observed in our simulations to hydrophobic collapse model of protein folding are discussed. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd. [source] Thermosensitive noncovalently bonded block copolymerlike micelles from interpolymer complexesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2004Dimitra Topouza Abstract Interpolymer complexes between polystyrene- b -poly(2-vinylpyridine), (PS-P2VP), and poly(methacrylic acid) (PMAA), have been studied in dioxane. Dioxane is a good solvent for PS-P2VP copolymers but it is a nonsolvent for PMAA at room temperature. In this way noncovalent bonded micelles are formed after mixing the solutions of the polymers at 60 °C and then allowing them to cool at room temperature. Static and dynamic light scattering as well as viscosity measurements have been used to study the dependence of aggregate mass and size as a function of the molar ratio of functional groups in PS-P2VP/PMAA mixtures, as well as temperature. Plots of apparent average molecular weight and hydrodynamic radius of the aggregates versus amine to carboxyl group ratio show a maximum at a ratio close to one. The size of the aggregates decreases at higher ratios because of the formation of more stable micelles with smaller cores. In all cases rather compact structures were formed, as evidenced by viscometry. The mass of the aggregates was found to decrease by an increase in temperature while hydrodynamic radii were increased. This was attributed to the increase of the thermodynamic quality of the solvent toward PMAA as temperature increases. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6230,6237, 2004 [source] Left-handed microstrip lines with multiple complementary split-ring and spiral resonatorsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2007-Bengin, V. Crnojevi Abstract Negative-permeability sub-wavelength particles, namely split-ring resonators and spiral resonators, are compared and their performances analyzed for a different number of concentric rings and spiral turns, respectively. Left-handed lines are designed, fabricated, and measured that use multiple complementary split-ring and spiral resonators. More compact structures are obtained, with improved characteristics. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1391,1395, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22427 [source] Ultrastructural Features of Myenteric Ganglia of Adult Wistar Rats (Rattus norvegicus)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2000M. R. M. Natali Summary The ultrastructural features of the ganglia of the myenteric plexus exhibit changes according to the animal species. These myenteric ganglia in the duodenum of adult rats of the Wistar strain were characterized ultrastructurally in this work. Those ganglia were depicted as compact structures, composed of neurones and glial cells, forming a dense neuropil surrounded by a continuous basal lamina and collagen fibrils. Glial cell bodies were smaller and apparently more frequent than neuronal cell bodies, being morphologically distinguished by nuclear features. In the neuronal extensions granular and agranular synaptic vesicles of different sizes predominate, in addition to mitochondria and myelinized profiles. Gliofilaments were not observed on the glial extensions of the rats. [source] | |||||||||||||