Home About us Contact
|
Home About us Contact | ||
|
|
||
Microscopic Techniques (microscopic + techniques)
Kinds of Microscopic Techniques Selected AbstractsSeasonal, sexual and developmental differences in hoopoe Upupa epops preen gland morphology and secretions: evidence for a role of bacteriaJOURNAL OF AVIAN BIOLOGY, Issue 2 2009Manuel Martín-Vivaldi The uropygial glands of birds serve multiple functions, and there is great interspecific variability in the composition and properties of their secretions. A special case is the secretion in the hoopoes Upupa epops, and green woodhoopoes Phoeniculus purpureus, which, contrary to the commonly white and odourless secretions, are dark with pungent odour. Recently, bacteria have been isolated from glands of both woodhoopoes and hoopoes and here we test the hypothesis that bacteria are responsible of some of the special properties of glands and secretions of this group of birds. We explore natural seasonal changes and intersexual differences in the properties of hoopoe glands and secretions, check the natural occurrence of bacteria within secretions, and analyse the effect of experimental injection of antibiotics on uropygial gland properties. Male glands underwent no seasonal changes, and their secretions were invariably white and odourless, very similar to female glands outside the breeding season. However, in comparison to the uropygial gland of non-breeding females, those of incubating females showed a marked increase in size and volume of secretion produced, which became dark and pungent. All these parameters increased until the hatching date and returned to values similar to those in the prelaying phase towards the end of the nestling period. Nestling glands produced secretions similar to those of females in colour and odour. Gland size of both females and nestlings predicted the amount of secretion produced. Microscopic techniques confirmed the presence of bacteria at high density and in active division in all dark secretions examined. The antibiotic treatment significantly reduced the load of enterococci in nestling glands, did not affect size of glands, but diminished the volume of secretion, which was lighter in colour than that of control nestlings. In nesting females, the experimental injection of antibiotic affected some measurements of gland size and secretion colour. Because the experiment did not affect general health estimates (immunocompetence, body condition or growing) of nestlings, our results suggest that some of the special properties of hoopoe glands are mediated by the presence of symbiotic bacteria. [source] Molecular physiology of adventitious root formation in Petunia hybrida cuttings: involvement of wound response and primary metabolismNEW PHYTOLOGIST, Issue 3 2009Amir H. Ahkami Summary ,,Adventitious root formation (ARF) in the model plant Petunia hybrida cv. Mitchell has been analysed in terms of anatomy, gene expression, enzymatic activities and levels of metabolites. This study focuses on the involvement of wound response and primary metabolism. ,,Microscopic techniques were complemented with targeted transcript, enzyme and metabolite profiling using real time polymerase chain reaction (PCR), Northern blot, enzymatic assays, chromatography and mass spectrometry. ,,Three days after severance from the stock plants, first meristematic cells appeared which further developed into root primordia and finally adventitious roots. Excision of cuttings led to a fast and transient increase in the wound-hormone jasmonic acid, followed by the expression of jasmonate-regulated genes such as cell wall invertase. Analysis of soluble and insoluble carbohydrates showed a continuous accumulation during ARF. A broad metabolite profiling revealed a strong increase in organic acids and resynthesis of essential amino acids. ,,Substantial changes in enzyme activities and metabolite levels indicate that specific enzymes and metabolites might play a crucial role during ARF. Three metabolic phases could be defined: (i) sink establishment phase characterized by apoplastic unloading of sucrose and being probably mediated by jasmonates; (ii) recovery phase; and (iii) maintenance phase, in which a symplastic unloading occurs. [source] Histologic and morphologic effects of valproic acid and oxcarbazepine on rat uterine and ovarian cellsEPILEPSIA, Issue 1 2010Ali Cansu Summary Purpose:, To determine the histologic and morphologic effects of valproic acid (VPA) and oxcarbazepine (OXC) on rat uterine and ovarian cells. Methods:, Fifty-six female prepubertal Wistar rats (21,24 days old and weighing between 47.5 and 58.1 g) were divided equally into four groups, which were given drinking water (controls), 300 mg/kg/day of VPA, 100 mg/kg/day of OXC or VPA + OXC via gavage, for 90 days. Ovaries and uteri of rats on proestrous and diestrous phases of estrous cycle were extirpated and placed in a fixation solution. The tissue specimens were assessed with apoptosis (TUNEL) staining protocols, eosinophil counting, and electron microscopic techniques. Results:, In uteri, apoptosis in stroma, mitochondrial swelling, and cristolysis were observed in the VPA group, and OXC led to negative effects on epithelial cell and intracellular edema. In ovaries, both drugs increased apoptosis and intracytoplasmic edema. Organelle structure disruption was also observed in the OXC group. More conspicuous degenerative modifications were determined in the VPA + OXC group. In uteri, the number of TUNEL-positive luminal epithelial cells was 7.20 ± 1.32 in controls, and significantly increased to 29.60 ± 1.58, 34.20 ± 2.53, and 54.80 ± 2.04 in VPA, OXC, and VPA + OXC groups, respectively (p < 0.001). The highest number of TUNEL-positive glandular epithelium cells was observed in the VPA + OXC group; however, the number of TUNEL-positive stroma cells was highest in the VPA group. The highest number of eosinophils in stroma was in the VPA group. Conclusion:, VPA and OXC trigger apoptotic and degenerative effects on rat uterine and ovarian cells. VPA also prevents implantation of embryo to the uterus and causes abortion via endometrial eosinophil infiltration. [source] A Single-Source Co/Li/O Organometallic Precursor for Nanocrystalline LiCoO2 , Synthesis, Formation Pathway, and Electrochemical Performance,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 29 2010Jayaprakash Khanderi Abstract A single-source precursor route to phase-pure LiCoO2 by employing the organometallic precursor [(COD)2CoLi(thf)2] (1) to introduce a Co/Li/O 1:1:2 stoichiometry is described for the first time. Compound 1 undergoes decomposition in the presence of oxygen, forming nanoscaled, electrochemically active LiCoO2 starting at a temperature as low as 200 °C. Its temperature-dependent formation pathway was studied by various spectroscopic and microscopic techniques. The transition temperature for the evolution of layered LiCoO2 is above 400 °C. Electrochemical studies indicate that the low-temperature modification of LiCoO2 can be obtained at 500 °C, showing moderate electrochemical battery performance. [source] The porcine snout , an in vitro model for human lips?EXPERIMENTAL DERMATOLOGY, Issue 2 2005U. Jacobi Abstract:, The morphology and histology of test sites commonly used to study the penetration of lip products differ significantly from those of the human lip itself. The aim of this study was to investigate whether the porcine snout could serve as an equivalent in vitro model for human lips. The lips of human test subjects and biopsies of porcine snout tissue were compared using histological and microscopic techniques. Using a dermatological laser scanning microscope, the penetration of topically applied fluorescent sodium fluorescein was investigated in vivo on human lips and in vitro on the porcine snout. Biopsies from the in vitro experiments were studied using fluorescence microscopy. Some parts of the porcine snout show a similar morphology and histology as human lips. The stratum corneum (SC) and the epidermis of the porcine snout are thicker than those of human tissue. Both in vivo and in vitro, the topically applied fluorescent dye was detected only on the skin surface and within the uppermost SC layer. These results indicate that porcine snout can be used as an in vitro model for human lips in penetration studies. Both human and porcine tissues exhibit an efficient barrier against the penetration of topically applied substances. [source] The microstratigraphic record of abrupt climate changes in cave sediments of the Western MediterraneanGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2001Marie-Agnès Courty The purpose of this paper is to illustrate how calcareous sediments from Pleistocene and Holocene rockshelters and open caves of the Western Mediterranean can provide a stratigraphic record of abrupt climate change. The method proposed here is based on microstratigraphic examination of sedimentary sequences using microscopic techniques. The most important processes for characterizing the sensitivity of each cave to climate variables are: (1) the modes and rate of carbonate sediment production, (2) the nature and intensity of the pedogenic processes responsible for the synchronous alteration of carbonate materials (either those derived from the cave walls or those deposited on the ground surface), and (3) the supply of allogenic sediments, particularly by eolian activity. The cave sediment sequences presented record the marked coolings known as Dansgaard-Oeschger stadials and Heinrich events that occurred during the Pleistocene and the Holocene, as demonstrated by the high resolution records from ice and deep sea cores. At Abric Romanì in northeastern Spain, a series of sharp climatic deteriorations of increasing severity is shown to have occurred synchronously with the transition from the Middle to the Upper Paleolithic, with a period of seasonal frost and strong winds at ca. 37,000 yr B.P., tentatively correlated with Heinrich event 4. At Pigeon Cave, Taforalt (northern Morocco), the transition from the Aterian to Ibero-Maurusian/Epipalaeolithic cultures is dated to around 24,000,20,000 yr B.P. and is punctuated by a series of short cold pulses with evidence for seasonal freezing, soil erosion, and minimal evapotranspiration. In El Miron cave in north-central Spain, the exceptional nature of the Younger Dryas cooling produced a marked destabilization of the cave walls and roof. At El Miron, the stratigraphic evidence for sediment removal due to the rapid percolation of snow melt under a degraded soil cover allows us to reconstruct the nature of the negative excursion at ca. 8200 yr B.P. This example also illustrates how climate-controlled pedogenic processes can create a stratigraphic signature which has often been confused with a sedimentary hiatus. We conclude that cave sediments provide a valuable record of Pleistocene and Holocene climate changes. In appropriate contexts, these sequences allow us to examine the ecological stress generated by these unique global events at a local and regional level and improve our understanding of the complex anthropological processes that occurred at the same time. © 2001 John Wiley & Sons, Inc. [source] Age-related changes in blood capillary endothelium of human dental pulp: an ultrastructural studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2003A. I. Espina Abstract Aim, To describe the ultrastructural changes that occur in pulpal blood capillaries as a result of ageing. Methodology, Thirty samples of healthy dental pulps were obtained from functional human permanent teeth. Two age groups were examined: young (10,17 years) and old (>60 years). The teeth were extracted under local anaesthesia using mepivacaine without adrenaline (Scandonest 3%, Septodont, Saint-Maur des Fossés, France) and split longitudinally in a bench press. The pulps were gently removed, immersed in fixative solution, sectioned and processed by conventional transmission electron microscopic techniques. Micrographs were taken from the endothelium, and the whole capillary area of each vessel was examined. Results, In young pulps, the endothelial cell layer was characterized by the presence of numerous pinocytotic vesicles and microvesicles, RER cisterns, free ribosomes, a small Golgi complex, centrioles, microtubules, microfilaments and mitochondria. In the endothelial cell cytoplasm of older pulpal vessels, pinocytotic vesicles and microvesicles, as well as microfilaments, were more numerous. In addition, lipid-like vacuoles, monogranular glycogen granules and extensive Golgi complexes with dilated cisterns were also present. Weibel-Palade bodies were observed in both age groups without showing variations related with age. Conclusions, The results obtained in capillaries of aged pulpal tissue suggest that the endothelium experiences morphological changes that could be associated with advancing age. [source] Blending of NR/BR/EPDM by reactive processing for tire sidewall applications.JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Abstract Cure incompatibility in NR/BR/EPDM blends is a crucial problem, affecting blend properties. In a previous study, it was demonstrated that the mechanical properties of such blends can be significantly improved by utilizing a reactive processing technique, in which a pretreated EPDM is first prepared by incorporating all compounding ingredients in the EPDM and subsequent preheating, prior to crossblending with premasticated NR/BR. In the present article, the pretreated EPDM-moieties are prepared using two different accelerators, N -cyclohexyl-2-benzothiazole sulfenamide (CBS) and 6-nitro MBTS. The latter was synthesized and applied for the purpose of IR characterization. The infrared (IR) spectra of the pretreated, extracted EPDM demonstrate absorption peaks associated with the IR absorption of the functional groups in the accelerator fragments, attached to the EPDM. NR/BR/EPDM (35/35/30) ternary blends are prepared by reactive mixing of the pretreated EPDM with CBS fragments attached with premasticated NR/BR on a two-roll mill. Their blend morphological features are studied using the atomic force microscopy (AFM) and transmission electron microscopy (TEM) microscopic techniques, in comparison with those of blends prepared by a conventional straight mixing method. Both the tapping mode AFM phase images and TEM micrographs clearly show that reactive mixing leads to more homogeneous blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:2547,2554, 2007 [source] Life stages and reproductive components of the Marmorkrebs (marbled crayfish), the first parthenogenetic decapod crustaceanJOURNAL OF MORPHOLOGY, Issue 3 2004Günter Vogt Abstract Recently, we briefly reported on the first case of parthenogenesis in the decapod Crustacea which was found in the Marmorkrebs or marbled crayfish, a cambarid species of unknown geographic origin and species identity. Curiously, this animal is known only from aquarium populations, where it explosively propagates. By means of light and electron microscopic techniques we have now investigated the reproductive components of this crayfish, using more than 100 specimens ranging from hatchling to repeatedly spawned adult. Additionally, we documented its principal life stages. Our results revealed that the external sexual characters and also the gonads of the marbled crayfish are purely female, making this fast-reproducing species a good model for investigating female reproductive features in crayfish. Testicular tissues, ovotestes, or male gonoducts, gonopores, or gonopods were never found, either in small juveniles or large adult specimens, confirming the parthenogenetic nature of this crayfish. Parthenogenesis may have arisen spontaneously or by interspecific hybridization since Wolbachia -like feminizing microorganisms were not found in the ovaries. The external sexual characters of the marbled crayfish are first recognized in Stage 4 juveniles and are structurally complete ,2 months after hatching in specimens of ,2 cm total length. In the same life stage the ovary is fully differentiated as well, although the oocytes are in previtellogenic and primary vitellogenic stages only. The architecture of the mature ovary and also the synchronous maturation of cohorts of primary vitellogenic oocytes by secondary vitellogenesis are in general agreement with data published on ovaries of bisexual crayfish. New results were obtained with respect to the muscular nature of the ovarian envelope and its extensive proliferation after the first spawning, the distribution of hemal sinuses in the ovarian envelope and in the interstitium around the oogenetic pouches, the high transport activity of the follicle cells, and the colonization of oogenetic pouches by previtellogenic oocytes that originate in the germaria. Investigation of the nuclei of oocytes in the germaria and oogenetic pouches revealed no signs of meiosis, as usually found in females of bisexual decapods, suggesting that parthenogenesis in the marbled crayfish might be an apomictic thelytoky. The detection of new rickettsial and coccidian infections in the ovary and further organs raises fears that the marbled crayfish might endanger native European species by transmission of pathogens once escaped into the wild. J. Morphol. 261:286,311, 2004. © 2004 Wiley-Liss, Inc. [source] A study of phase separation in peptide-loaded HPMC films using Tzero -modulated temperature DSC, atomic force microscopy, and scanning electron microscopyJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2004Samana Hussain Abstract Despite the widespread use of drug-loaded polymeric systems, there is still considerable uncertainty with regard to the nature of the distribution of the drug within the polymer matrix. The aim of this investigation was to develop thermal and microscopic techniques whereby the miscibility and spatial distribution of a model peptide, cyclosporin A (CyA), in hydroxypropyl methylcellulose (HPMC) films may be studied. The new technique of Tzero -modulated temperature differential scanning calorimetry (Tzero MTDSC), scanning electron microscopy (SEM), and pulse force mode atomic force microscopy (PFM-AFM) were used in conjunction to study films prepared using a solvent evaporation process, with a solvent extraction study performed to elucidate the nature of the observed phases. Tzero MTDSC studies showed glass transitions for both the HPMC and CycA, with the Tg for the HPMC and CycA seen for the mixed systems. SEM showed two spherical phases of differing electron density. PFM-AFM also showed spheres of differing adhesion that increased in size on addition of drug. Pixel intensity analysis indicated that the smaller spheres corresponded to CycA. Exposure of the films to dichloromethane, in which CycA is soluble but HPMC is not, resulted in the presence of voids that corresponded well to the spheres suggested to correspond to the drug. It was concluded that the system had undergone extensive or complete phase separation, and that the thermal and microscopic techniques outlined above are an effective means by which this issue may be studied. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1672,1681, 2004 [source] Solution, thermal and optical properties of novel poly(pyridinium salt)s derived from conjugated pyridine diamines,JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2010Alexi K. Nedeltchev Abstract Several novel poly(pyridinium salt)s with heterocyclic pyridine moieties in their backbones with tosylate and triflimide counterions were prepared by either ring-transmutation polymerization reaction of phenylated-bis(pyrylium tosylate) with isomeric pyridine diamines of 4-phenyl-2,6-bis(4-aminophenyl)pyridine in dimethyl sulfoxide (DMSO) for 48 h at 130,140 °C or by metathesis reaction of the respective tosylate polymers with lithium triflimide in DMSO at about 60 °C. Their chemical structures were characterized by FTIR, 1H, 13C NMR spectroscopy, and elemental analysis. Their number-average molecular weights (Mn) were in the range of 8,000,51,000 and their polydispersities in the range of 1.18,2.13 as determined by gel permeation chromatography. They had excellent thermal stabilities of 340,458 °C and high glass transition temperatures >200 °C. As they showed good solubilities in common organic solvents, their solution properties were also characterized for their lyotropic liquid-crystalline properties with polarizing optical microscopy (POM) studies. Their photoluminescent properties were examined by using a spectrofluorometer in both solution and solid states. Their quantum yields were rather low, which were in the range of 1.3,2.0%. Additionally, hand-drawn fibers from the melts were examined to determine their morphologies with a number of microscopic techniques including POM, scanning electron microscopy, and transmission electron microscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 [source] Bronze Age painted plaster in Mycenaean Greece: a pilot study on the testing and application of micro-Raman spectroscopyJOURNAL OF RAMAN SPECTROSCOPY, Issue 8-9 2004Ann Brysbaert Abstract Since the first discoveries of Minoan and Mycenaean painted plaster around the end of the 19th and early 20th centuries, iconographic and, to a lesser extent, technological studies have gone hand in hand in order to understand how these prehistoric societies were able to produce some of the earliest and most significant works of art in Bronze Age Europe and the eastern Mediterranean. These paintings claim to be among the first to be executed in the buon fresco technique. Past technological studies employed wet chemical methods, x-ray diffraction (XRD), optical emission spectroscopy and a range of microscopic techniques based on cross-sections of samples in order to investigate these fragmentary paintings. Most of these methods required destructive sampling and this is now, rightly so, very much restricted. Consequently, other non-micro-destructive approaches are being tested at present. Micro-Raman spectroscopy (MRS) has proven more than once its potential for non-destructive analysis of works of art and in archaeology in the recent past. Its application to this early fragmentary material is presented here for the first time. Interesting results were the identification of both organic (indigo) and non-crystalline materials (limonite), which complements the knowledge obtained from traditionally used techniques. Although not without problems (high fluorescence prevented identification of Egyptian Blue), non-destructive MRS yielded results comparable to XRD and provided the first identification of indigo blue on this medium, and can hence be considered very useful in future sample-reducing strategies considering these scarce materials. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effect of Filler Content on the Dielectric Properties of PTFE/ZnAl2O4,TiO2 CompositesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2008Sherin Thomas ZnAl2O4,TiO2 (ZAT)/polytetrafluoroethylene (PTFE) composites were prepared by powder processing method. The structure and microstructure of the composites were analyzed using X-ray diffraction and scanning electron microscopic techniques. The effect of different volume fraction of ZAT (0,0.6) on the dielectric properties of the composites was investigated at 1 MHz and at the microwave frequency of 7 GHz. The dielectric properties (relative permittivity and dielectric loss) were found to increase with the ZAT content. The samples with 60 vol.% of ZAT filler showed a relative permittivity of 3.9 and dielectric loss of 0.009, respectively, at 7 GHz. The variation of relative permittivity and dielectric loss showed only a very small variation with temperature in the range 25°,70°C for various ZAT/PTFE composites. The relative permittivity obtained experimentally were compared with that of the theoretical values predicted using modified Lichtenecker, Jayasundere,Smith, and Series mixing formulae. They were found to agree well with the predicted values for low filler content. [source] 157 nm fluorine laser ablation of wooden surfaces as an improved preparation technique for microscopyLASER PHYSICS LETTERS, Issue 1 2005M. Kopp Abstract By means of 157 nm VUV short-wavelength laserirradiation the wood layer of damaged cells near the surface as well as deeper wood regions can be removed. As this is a nonthermal laser ablation-process, oxidation of the wood surface exposed to 157 nm under N2 -atmosphere is avoided even with high power densities. By applying a mechanical pre-treatment process the wood structure is compressed and can then be removed with almost no damage. Four types of wood - spruce, pine, beech and oak - were ablated in all three main cutting directions prescribed for an anisotropic material such as wood. Several microscopic techniques were used. To measure the ablation depth LSM was applied. The surface roughness as well as the quality of the laser ablation was determined by using LV-SEM. CAM was used to measure the contact angle and thereby calculate the surface energy. Ablation can be carried out regardless of the cutting direction used to obtain clean and open surfaces free of artefacts. (© 2005 by ASTRO, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Application of microscopy in authentication of traditional Tibetan medicinal plant Halenia ellipticaMICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2008Jie Li Abstract Halenia elliptica D. Don, a popularly used ethnodrug from Qinghai-Tibetan plateau, was studied to reveal the indispensable morphoanatomic details. The fixed, sectioned, and stained plant materials as well as the epidermis, powder, and maceration materials were studied using light microscope according to the usual microscopic techniques. The results of the microscopic features were systematic described and illustrated. In the root, an endodermal cell was divided into 8-16-22 and 38-50-62 daughter cells in transverse section and in face view, respectively, and 9-11-13 phloem strands were present in primary structure; in the stem, stone cells were observed in the cortex, pericycle, and external phloem while 17-19-21 internal phloem strands were present in an incontinuous ring; in the pedicel, 8-10-12 internal phloem strands were observed to form an incontinuous ring; anisocytic and anomocytic stomata were present in leaf and sepal epidermis; pollen grain was with three germinal apertures and furrows; a few tracheids, a large number of spiral vessels, and various fibers were observed. Also, semiquantitative and quantitative micrographic parameter tables were simultaneously presented. Further, the key authentication parameters were concluded. The study indicated that light microscopy and related techniques could be unambiguously applied to the authentication of Halenia elliptica. Microsc. Res. Tech., 2008. © 2007 Wiley-Liss, Inc. [source] Use of confocal and multiphoton microscopy for the evaluation of micro-optical components and emittersMICROSCOPY RESEARCH AND TECHNIQUE, Issue 4 2004J.M. Girkin Abstract We report on the application of confocal and multiphoton microscopic techniques for the evaluation of the latest generation of micro optical components. The optical emitting characteristics of arrays of matrix addressable GaN micrometer-sized light emitting diodes (micro-LEDs) have been measured using a commercial confocal microscope utilising the LEDs' own emission along with reflection confocal microscopy to determine the surface structure. Multiphoton induced luminescence from the 10,20-micron diameter emitters has also been used to examine the structure of the device and we compare this with electrically induced emission. In related work, the optical properties of micro lens arrays (10,100-micron diameter) fabricated in SiC, Sapphire, and Diamond have been determined using transmission confocal microscopy. Such optical microscopy techniques offer a simple, non-destructive method to determine the structure and performance of such novel devices. Microsc. Res. Tech. 64:293,296, 2004. © 2004 Wiley-Liss, Inc. [source] Non-invasive tracking of avian development in vivo by MRINMR IN BIOMEDICINE, Issue 4 2009Bianca Hogers Abstract Conventional microscopic techniques, to study embryonic development, require large numbers of embryos and are invasive, making follow-up impossible. We explored the use of in vivo MRI to study embryonic development, in general, and cardiovascular development in particular, over time. Wild-type quail embryos (n,=,11) were imaged at embryonic days 3, 5, 7, 9, and 11, covering the main time course of embryonic heart development. On each imaging day cardiac morphology was evaluated and embryonic length was measured. MRI-embryos as well as control embryos (n,=,11) were sacrificed at day 11 and scored for external malformations, while embryonic wet weight and stage were determined. In addition, venous clipped embryos (n,=,4), known to develop cardiovascular malformations, were scanned at regular intervals and sacrificed at day 9 for histological analysis ex vivo. We were able to follow heart development of individual quail embryos inside their shell non-invasively over time, with sufficient detail to study cardiac morphology in vivo. We did not find any adverse effect of the repeated MRI examinations on morphology, length, or weight. Prenatally diagnosed malformations, like ventricular septal defects and aortic arch interruptions were confirmed by histology. In conclusion, micro-MRI can be used to evaluate in vivo early embryonic development and to diagnose cardiovascular malformations prenatally. Copyright © 2008 John Wiley & Sons, Ltd. [source] Mastoiditis,Paleopathological evidence of a rarely reported diseaseAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Stefan Flohr Abstract Since antibiotics have become available, mastoiditis has become a rare disease in modern Western societies. However, it is still common in developing countries. It can be hypothesized that in earlier historical and prehistoric times, mastoiditis must have posed a serious threat to people's lives, and that the prevalence of this disease is probably underrepresented in the paleopathological literature. The present study identifies pathological changes in the pneumatized cells of the mastoid process in human skeletal samples from two early medieval cemeteries from Germany (Dirmstein: n = 152 mastoids, Rhens: n = 71 mastoids), using macroscopic, endoscopic, low-power microscopic, scanning-electron and light microscopic techniques, and draws some epidemiological conclusions as to the frequency of the disease diagnosed in the archaeological samples. Osseous changes because of mastoiditis were diagnosed in 83.4% of the temporal bones. The frequency in the skeletal sample from Dirmstein was higher than in the sample from Rhens. In both populations, males were more often affected than females and older individuals more often than younger individuals. The high frequency of mastoiditis observed was most likely due to an accumulation of osseous changes during individual lifetimes and supports the hypothesis that mastoiditis was a serious health problem in pre-antibiotic times. It may be assumed that subclinical forms of mastoiditis and their osseous manifestations may even nowadays occur more often than was previously thought. It is suggested that the disease should be given more consideration in paleopathological investigations. Am J Phys Anthropol 2009. © 2008 Wiley-Liss, Inc. [source] Intraneuronal localization of Nogo-A in the ratTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2003Wei-Lin Jin Abstract Nogo-A is known to be a myelin-associated protein with strong inhibitory effect on neurite outgrowth and has been considered one of the major factors that hinder fiber regeneration in the central nervous system. Recent studies have demonstrated widespread occurrence of nogo-A mRNA and Nogo-A protein in neurons. Our concurrent immunohistochemical study substantiated the widespread distribution of neuronal Nogo-A. The present study was thus focused on its intraneuronal distribution in the central nervous system, using Western blotting, immunohistochemical, and immunogold electron microscopic techniques. Western blotting of the nucleus, cytoplasm, and membrane subcellular fractions of the cerebellum and spinal cord tissues demonstrated that all three fractions contained Nogo-A. Nogo-A immunoreactivity could be identified under confocal microscope in the nucleus, perikayon, and proximal dendrite and along the cell membrane. Under the electron microscope, the perikaryonal Nogo-A immunogold particles were mainly distributed at polyribosomes and rough endoplasmic reticulum, suggesting its relationship with translation process. The immunogold particles could also be found beneath or on the plasma membrane. In the nucleus, the Nogo-A immunogold particles were found to be localized at the chromatins of the nucleus, indicating its possible involvement in gene transcription. The presence of Nogo-A in the nucleus was further supported by transfection of COS-7L cells with nogo-A. This study provides the first immunocytochemical evidence for intraneuronal distribution of Nogo-A. Apparently, the significance of Nogo-A in the central nervous system is far more complex than what has been envisioned. J. Comp. Neurol. 458:1,10, 2003. © 2003 Wiley-Liss, Inc. [source] Regulation of the epididymal receptor tyrosine kinase ros by the protein tyrosine phosphatase SHP-1AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2002Rico Pusch The SH2 domain PTP SHP-1 was recently identified as a potent negative regulator of the orphan receptor tyrosine kinase Ros, an important regulator of epidimys differentiation (Keilhack et al. J Cell Biol 2001; 152:325,334). Phosphorylated Ros strongly and directly associates with SHP-1 in yeast-two-hybrid, GST pull-down, and coimmunoprecipitation experiments. Catalytically inactive SHP-1C455S exhibits greatly elevated binding to phosphorylated Ros. Direct Ros,SHP-1 interaction is mediated by the SHP-1 N-terminal SH2 domain and Ros phosphotyrosine 2267. Overexpression of SHP-1 results in Ros dephosphorylation and effectively down-regulates Ros-dependent proliferation and transformation. Elevated phosphorylation of Ros in ,viable motheaten (me-v)' mice which, have strongly reduced SHP-1 activity, suggests that Ros signaling is under control of SHP-1 in vivo. Thus sterility of male me-v mice seems to be related to dysregulation of Ros. A synthetic phosphopeptide derived from the Ros sequence around Y2267 potently activates recombinant SHP-1 in vitro but is not a good substrate for SHP-1. In contrast, phosphorylation sites in the activation loop of Ros are effectively dephosphorylated. Based on these observations we propose a mechanistic model of Ros,SHP-1 interaction. Using fusion proteins of SHP-1 variants and of Ros with GFP-proteins of different spectral characteristics the interaction of Ros and SHP-1 can be visualized in intact cells by different microscopic techniques. [source] Nicotinic acetylcholine receptors on basophils and mast cellsANAESTHESIA, Issue 12 2006P. S. Sudheer Summary Anaphylaxis in response to drugs administered during anaesthesia is a rare but potentially catastrophic event. The anaesthetic drugs most commonly associated with anaphylaxis are neuromuscular blocking agents. As these drugs act on the nicotinic acetylcholine receptor of the neuromuscular junction, potentiation of anaphylaxis by a nicotinic receptor on basophils and mast cells is plausible. The aim of this study was to investigate whether nicotinic acetylcholine receptors are present on a human basophil and mast cell lines as their presence may suggest a mechanism of associated anaphylaxis. Nicotinic receptors were demonstrated on a basophil and a mast cell line using an ,-bungarotoxin,fluorescein conjugate by flow cytometry and by both conventional and confocal microscopic techniques. The identity of this receptor was confirmed by reverse transcriptase PCR and quantitative PCR. [source] Variable expression of tenascin-C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lungAPMIS, Issue 2 2010RIITTA KAARTEENAHO Kaarteenaho R, Sormunen R, Pääkkö P. Variable expression of tenascin-C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung. APMIS 2010; 118: 91,100. The aim of this study was to analyse the expression of tenascin-C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung, which is a rare tumour of unknown aetiology. Nine patients with an inflammatory myofibroblastic tumour of lung were studied by immunohistochemistry for the presence of tenascin-C, osteopontin, fibronectin and alpha-smooth muscle actin, which is a common marker for myofibroblasts. The ultrastructure of myofibroblasts was confirmed by transmission electron microscopy. The expression of tenascin-C, osteopontin, fibronectin and alpha-smooth muscle actin was also studied by immunoelectron microscopy. All cases displayed all of the studied extracellular matrix proteins and also alpha-smooth muscle actin-positive spindle-shaped fibroblastic cells that were undoubtedly myofibroblasts. The immunoelectron microscopic studies demonstrated labelling for alpha-smooth muscle actin in intracellular filament bundles within myofibroblasts, for fibronectin in the extracellular filaments of the fibronexus and for tenascin-C extracellularly often adjacent to myofibroblasts. Labels for osteopontin were observed within myofibroblasts and plasma cells. These results demonstrate that tenascin-C, osteopontin and fibronectin were expressed in all three kinds of subtypes of inflammatory myofibroblastic tumours of the lung and further, variable amounts of myofibroblasts could be observed by light and transmission electron microscopy as well as by immunoelectron microscopic techniques. [source] | |||||||||||||||||||