Showing papers on "Ultrastructure published in 2011"
TL;DR: To examine the mechanism of ozone‐induced damage to cytoplasmic membrane and cell ultrastructure of Pseudomonas aeruginosa ATCC27853.
Abstract: Aims: To examine the mechanism of ozone-induced damage to cytoplasmic membrane and cell ultrastructure of Pseudomonas aeruginosa ATCC27853.
Methods and Results: Cell suspensions of Ps. aeruginosa ATCC27853 were treated with ozonated water. The leakages of cellular potassium (K+), magnesium (Mg2+) and adenosine triphosphate (ATP), determined by inductively coupled plasma/mass spectrometry (ICP/MS) and a commercial bioluminescence assay kit, were to assess ozone-induced damage to the cytoplasmic membrane. Maximum leakages of K+ and Mg2+ were attained, respectively, at 0·53 mg l−1 ozone after 0·5 and 2 min with >99% inactivation of culturable bacteria, while that of ATP was achieved at 0·67 mg l−1 ozone after 1 min. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed that treated cells retained intact shapes and cytoplasm agglutinations and vacuoles occurred.
Conclusions: Ozone inactivates Ps. aeruginosa ATCC27853 by the combined results of increased cytoplasmic membrane permeability and cytoplasm coagulation, rather than by severe membrane disruption and cell lysis.
Significance and Impact of the Study: Pseudomonas aeruginosa is a common water-related pathogen. These insights into the leakage of cytoplasmic components and ultrastructural changes provide evidence for the mechanisms of ozone-mediated inactivation.
61 citations
TL;DR: The results show that many ultrastructural characters are variable within this superfamily and could be useful for phylogeny and compared to the digenean spermatology literature.
Abstract: The ultrastructure of the mature spermatozoon of Gyliauchen sp., a parasite of the dusky rabbitfish Siganus fuscescens, was studied by transmission electron microscopy. The spermatozoon possesses two axonemes of the 9+"1" pattern of Trepaxonemata, four attachment zones, one mitochondrion, a nucleus, cortical microtubules, external ornamentation of the plasma membrane, and spine-like bodies. The main characteristics of this spermatozoon are the presence of one mitochondrion, spine-like bodies not associated with the external ornamentation, and a posterior extremity of type 3 that is characterized by the following sequence: posterior extremity of the nucleus then posterior extremity of the second axoneme. Numerous other ultrastructural features are also discussed and compared to the digenean spermatology literature. This is the first study of a member of the Gyliauchenidae and the fourth within the Lepocreadioidea. The results show that many ultrastructural characters are variable within this superfamily and could be useful for phylogeny.
49 citations
Book•
05 Oct 2011
TL;DR: In vitro studies of the peri-implantation phase of human embryos and effects of culture and cryopreservation on human oocyte and embryo ultrastructure and function are presented.
Abstract: 1. Mammalian spermatogenesis and its disorders in man.- 2. Life history of the human female germ cell: Ultrastructural aspects.- 3. Ultrastructure of fetal ovary including oogenesis.- 4. The ovary and ovulation: A three-dimensional ultrastructural study.- 5. Developmental failure in human reproduction associated with preovulatory oogenesis and preimplantation embryogenesis.- 6. Effects of culture and cryopreservation on human oocyte and embryo ultrastructure and function.- 7. In vitro studies of the peri-implantation phase of human embryos.
40 citations
TL;DR: The histopathology and ultrastructure of psittacine atherosclerosis were found to be similar to other avian and mammalian species and seven lesion types could be described, which were similar to the human classification system.
Abstract: Atherosclerosis is a degenerative and inflammatory vascular disease characterized in mammals and birds by the accumulation of inflammatory cells, lipids, calcium, and formation of large fibrofatty lesions within the intima of arteries resulting in the disorganization of the arterial wall and stenosis of the lumen. Despite the high incidence of atherosclerosis in parrots and the high number of case reports, there are few pathologic investigations and the ultrastructural study of the lesions has not been documented. Sixty-three major arteries were collected from 24 psittacine birds of 11 species during routine post-mortem examinations. Samples from the major arteries were fixed in 2% paraformaldehyde and 1.25% glutaraldehyde, and processed for transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Additional samples were fixed in 10% formalin and embedded in paraffin for histological examination. Additional histochemical stains for calcium, elastic fibres, and lipid were performed. Toluidine blue-stained 0.5 µm-thick resin sections were also obtained. Digital image analysis was performed to provide objective quantitative information on the different lesions. The histopathology and ultrastructure of psittacine atherosclerosis were found to be similar to other avian and mammalian species. Seven lesion types could be described, which were similar to the human classification system. Digital image analysis, TEM, and SEM helped to further describe the lesions and refine the classification system. TEM findings were similar to other avian and mammalian species with the notable presence of macrophage-derived and smooth muscle cell-derived foam cells and extracellular lipid. SEM revealed various stages of endothelial surface defects and, occasionally, adherent blood cells.
38 citations
TL;DR: According to lanthanum-tracer study, salt can be excreted apoplastically, and the heavy element can be transported via endocytosis vesicles, and by Golgi, endoplasmic reticulum, and lysosome network toward the storage vacuoles.
Abstract: The secreting glandular trichomes are recognized as an efficient structure that alleviates salt effects on Atriplex halimus. They are found on buds, young green stems, and leaves. They occupy both the leaf surfaces and give them a whitish color. Their histogenesis and ultrastructure were investigated in the third young leaves. They appear in early stage of plant development and its initiation continuous until just the leaf final development state. Each trichome contains two parts; a stalk which has high electron opacity, embedded in epidermal cells, and bears a second one which is unicellular, called bladder cell and has a low electron density. The bladder cell appears as a huge vacuole and the well-reduced cytoplasm which is pushed close to the wall, contains only a few organelles. Concurrently, the use of silver chloride precipitation technique shows that, in secretion process, salt follows a symplasmatic pathway which is consolidated by the presence of numerous plasmodesmata between the stalk cell(s), and the bladder one and the neighboring mesophyll cells. In addition, according to lanthanum-tracer study, salt can be excreted apoplastically. In fact, the heavy element can be transported via endocytosis vesicles, and by Golgi, endoplasmic reticulum, and lysosome (G.E.R.L.) network toward the storage vacuoles.
31 citations
TL;DR: The spermatogenic process of P. lineatus follows the pattern of mammals with some specificity, as the process of formation of the acrosome and the presence of the perfuratorium, and the simpler ultrastructure of its spermatozoon shows a pattern more closely related to the sperm cells of humans and other primates.
28 citations
TL;DR: It is hypothesized that the seminal receptacle and the spermathecal duct have different functional roles, despite having a similar general structural organization.
Abstract: A morphological and ultrastructural study of the spermatheca of some species of Orthoptera Tettigoniidae was carried out to understand the role of this female organ in the reproductive biology because no literature exists about it in this insect group. In all the examined species, the spermatheca is of ectodermal origin and is composed of a seminal receptacle, mainly involved in the collection and storage of the spermatozoa, and of a spermathecal duct. In both these organs, the epithelium of the wall is made up of two different cell types: cuticle-forming cells, underlying the cuticular intima, and gland cells. Both of these cell types have secretory features that differ among the species and also within the same species, in relation to the tracts examined. In particular, the ultrastructure of the distal tract of the spermathecal duct indicates a more marked secretory activity than in the other tracts of the duct. This activity is often accompanied by ultrastructural aspects, suggesting a lysis a...
27 citations
TL;DR: The results indicate that DC are abundant constituents of normal human salivary glands, and their location within ductal and acinar epithelium suggests a role in responding to foreign antigens and/or maintaining immunological tolerance tosalivary proteins.
Abstract: Dendritic cells (DC) are believed to contribute to development of autoimmune sialadenitis, but little is known about their distribution in normal salivary glands. In this study, DC were identified and their distribution was determined in normal human parotid and submandibular glands. For light microscopy, salivary gland sections were stained with H&E or immunocytochemically using antibodies to DC markers. Transmission electron microscopy (TEM) was used to evaluate the ultrastructural characteristics of DC. In H&E sections, elongated, irregularly shaped nuclei were occasionally seen in the striated and excretory duct epithelium. Immunolabeling with anti-HLA-DR, anti-CD11c and anti-S100 revealed DC with numerous processes extending between ductal epithelial cells, often close to the lumen. Morphometric analyses indicated that HLA-DR-positive DC occupied approximately 4–11% of the duct wall volume. Similar reactive cells were present in acini, intercalated ducts and interstitial tissues. TEM observations revealed cells with indented nuclei containing dense chromatin, pale cytoplasm with few organelles, and lacking junctional attachments to adjacent cells. These results indicate that DC are abundant constituents of normal human salivary glands. Their location within ductal and acinar epithelium suggests a role in responding to foreign antigens and/or maintaining immunological tolerance to salivary proteins.
26 citations
01 Jan 2011
TL;DR: This chapter provides an overview of diatom wall construction, morphology, structure, and structure, cell cytology, and aspects of wall morphogenesis, as well as stressing the importance of applying descriptive terminology appropriately and consistently.
Abstract: This chapter provides an overview of diatom wall construction, morphology (light microscopy [LM]), and structure (electron microscopy [EM]), cell cytology, and aspects of wall morphogenesis. It also seeks to highlight areas where more information is required, while stressing the importance of applying descriptive terminology appropriately and consistently.
24 citations
TL;DR: The localisation of protein, phenols and neutral polysaccharides in the tuberous roots after staining with different dyes generally used in cytochemical analyses lead to the hypothesis of interaction of fructose polymers with cell membrane and possibly their role in membrane stabilisation in plants subjected to stressing environmental conditions.
Abstract: Campuloclinium chlorolepis (Baker), an herbaceous species of the Cerrado, accumulates inulin-type fructans in the tuberous roots. Plants were collected in the Cerrado and the roots analysed using light and scanning electron microscopy. The presence of fructans was assessed by specific stain reactions and by high performance anion exchange chromatography. Here, we report the localisation of protein, phenols and neutral polysaccharides in the tuberous roots after staining with different dyes generally used in cytochemical analyses. Results showed the presence of fructans inside and outside cells from all tissues of tuberous roots with the exception of the epidermis. When visualised by scanning electron microscopy, globular bodies consistent with typical inulin spherocrystals were clearly detected under polarised light. These globular bodies varied in size according to location, being smaller in the cortical tissue and larger in the central cylinder. The localisation of fructans outside the cell in several tissues of the tuberous roots clearly shown by histochemical and ultrastructural analyses lead to the hypothesis of interaction of fructose polymers with cell membrane and possibly their role in membrane stabilisation in plants subjected to stressing environmental conditions.
23 citations
TL;DR: In this paper, the authors examined morphological and anatomical features of F. suspensa stem using light microscopy and scanning electron microscopy (SEM) and showed that the slenderness and Runkel ratio is 51 and 0.67, respectively.
TL;DR: The authors' treatment protocol does not lead to ultrastructural alteration in theserotonergic dorsal raphe cell bodies and in their proximal neurites but causes impairment in cortical serotonergic axons.
Abstract: 3,4-Methylenedioxymethamphetamine (MDMA, “ecstasy”) is a widely used recreational drug known to cause selective long-term serotonergic damage. The aim of this study was to characterize the ultrastructure of serotonergic pericarya and proximal neurites in the dorsal raphe nucleus as well as the ultrastructure of serotonergic axons in the frontal cortex of adolescent Dark Agouti rats 3 days after treatment with 15 mg/kg i.p. MDMA. Light microscopic immunohistochemistry and pre-embedding immunoelectron microscopy with a novel tryptophan hydroxylase-2 (Tph2) specific antibody, as a marker of serotonergic structures. Light microscopic analysis showed reduced serotonergic axon density and aberrant swollen varicosities in the frontal cortex of MDMA-treated animals. According to the electron microscopic analysis, Tph2 exhibited diffuse cytoplasmic immunolocalization in dorsal raphe neuronal cell bodies. The ultrastructural-morphometric analysis of these cell bodies did not indicate pathological changes or significant alteration in the cross-sectional areal density of any examined organelles. Proximal serotonergic neurites in the dorsal raphe exhibited no ultrastructural alteration. However, in the frontal cortex among intact fibers, numerous serotonergic axons with destructed microtubules were found. Most of their mitochondria were intact, albeit some injured axons also contained degenerating mitochondria; moreover, a few of them comprised confluent membrane whorls only. Our treatment protocol does not lead to ultrastructural alteration in the serotonergic dorsal raphe cell bodies and in their proximal neurites but causes impairment in cortical serotonergic axons. In these, the main ultrastructural alteration is the destruction of microtubules although a smaller portion of these axons probably undergo an irreversible damage.
TL;DR: It is argued that a perturbed phosphoinositide metabolism most likely induces these observed abnormalities and hypothesize that a disorganized cytoskeleton and excessive membrane trafficking mediate the cell wall defects.
Abstract: SAC9 is a putative phosphoinositide phosphatase in Arabidopsis thaliana involved in phosphoinositide signaling. sac9-1 plants have a constitutively stressed phenotype with shorter roots which notably accumulate phosphatidylinositol 4,5-bisphosphate and its hydrolysis product inositol trisphosphate. We investigated the primary roots of sac9-1 seedlings at the cytological and ultrastructural level to determine the structural basis for this altered growth. Despite the normal appearance of organelles and cytoplasmic elements, our studies reveal extreme abnormalities of cell wall and membrane structures in sac9-1 primary root cells, regardless of cell type, position within the meristematic area, and plane of section. Cell wall material was deposited locally and in a range of abnormal shapes, sometimes completely fragmenting the cell. Simple protuberances, broad flanges, diffuse patches, elaborate folds, irregular loops and other complex three-dimensional structures were found to extend randomly from the pre-existing cell wall. Abundant vesicles and excessive membrane material were associated with these irregular wall structures. We argue that a perturbed phosphoinositide metabolism most likely induces these observed abnormalities and hypothesize that a disorganized cytoskeleton and excessive membrane trafficking mediate the cell wall defects.
TL;DR: Spermiogenesis and spermatozoon ultrastructure of the caryophyllidean cestode Breviscolex orientalis Kulakovskaya, 1962, first member of the family Capingentidae studied, a parasite of cyprinid fish Abbottina rivularis, are described using transmission electron microscopy.
Abstract: Spermiogenesis and spermatozoon ultrastructure of the caryophyllidean cestode Breviscolex orientalis Kulakovskaya, 1962, first member of the family Capingentidae studied, a parasite of cyprinid fish Abbottina rivularis, are described using transmission electron microscopy. Spermiogenesis in B. orientalis follows the Type II pattern described by Bâ and Marchand (Mem Mus Natl Hist Nat 166:87–95, 1995) for cestodes. It begins with the formation of a zone of differentiation containing a large nucleus and a pair of centrioles. The centrioles are separated from one another by an intercentriolar body composed of three electron-dense layers. Each centriole is associated with typical striated roots. At the beginning of the spermiogenesis, an electron-dense material is observed in the apical region of the differentiation zone. During the initial stage of spermiogenesis, one of the centrioles gives rise to a free flagellum, which then rotates and undergoes proximodistal fusion with the cytoplasmic protrusion of the differentiation zone. The mature spermatozoon of B. orientalis corresponds to the Type III pattern described by Levron et al. (Biol Rev 85:523–543, 2010). It is characterized by the absence of mitochondrion and crested body. Five regions of the mature spermatozoon are differentiated. The main ultrastructural characteristics are: one axoneme of 9 + “1” trepaxonematan pattern, cortical microtubules and nucleus. The comparison of the spermiogenesis of B. orientalis with those of the other caryophyllidean species demonstrates some variation within the order relative to the presence and morphology of the intercentriolar body, the presence of slight rotation of the flagellar bud and a complete proximodistal fusion of the free flagellum with a cytoplasmic protrusion.
TL;DR: The data provide the first estimates of genetic variation in sperm ultrastructure for any species, and give evidence for the persistence of genetic variations in ultrast structure required for the rapid and divergent evolution that characterizes spermatozoa generally.
Abstract: Sperm competition is thought to be an important selective pressure shaping sperm form and function. However, few studies have moved beyond gross examinations of sperm morphology. Sperm length is subject to sexual selection via sperm competition in the scarab beetle Onthophagus taurus. Here, the structure and ultrastructure of spermatozoa in this species were investigated using light and electron microscopy. Spermatozoa were found to be filiform, measuring about 1,200 mm in length. The sperm head consists of a three-layered acrosome and a nuclear region bearing the anterior extension of the centriole adjunct. Acrosome and nuclear regions are bilaterally symmetric, with their axes of symmetry being orthogonal to each other. Head and flagellar structures are connected by a well-developed centriole adjunct. The sperm heads are asymmetrically surrounded by accessory material and embedded into the cytoplasm of the spermatocyst cell. The accessory material is produced inside the spermatids and then transferred to the outside due to a new membrane formed around the sperm’s organelles. The old spermatid membrane separates the accessory material from the cyst cell. The flagellum contains a 9+9+2 axoneme, two accessory bodies, and two mitochondrial derivatives of unequal size. The major mitochondrial derivative is significantly larger than the minor one. The axoneme is arranged in a sinusoidal manner parallel along the major mitochondrial derivative. The spermatozoa show no progressive motility when released in buffer solution which is likely to be the result of the flagellar arrangement and the structure of the major mitochondrial derivative. The cross-sectional area of the minor and the major mitochondrial derivatives show different patterns of genetic variation. The data provide the first estimates of genetic variation in sperm ultrastructure for any species, and give evidence for the persistence of genetic variation in ultrastructure required for the rapid and divergent evolution that characterizes spermatozoa generally.
TL;DR: In this article, the authors examined the effect of muscle stretching on meat quality and ultrastructure of biceps femoris (BF) from beef and concluded that muscle stretching is a useful method for improving tenderness by stretching muscles.
TL;DR: New insights to the comparative spermatology of Siniperca fishes are provided and will be useful to the existing knowledge of the sinipercid fishes in systematic characters, biodiversity conservation and reproduction.
TL;DR: Hippodamia convergens, the convergent lady beetle, is available for aphid control in home gardens and in commercial food production systems throughout the United States and Canada and it is proposed that the microsporidium in H. converGens be given the name Tubulinosema hippodamiae.
TL;DR: The morphology and ultrastructural changes in the epithelium in equine large colonic mucosa after I/R, and the response of inflammatory cells to injury are described to provide information on early changes in barrier properties, repair and inflammation in Equine colon after ischaemia and reperfusion.
Abstract: Summary Reason for performing study: Ultrastructural changes in the epithelium can provide information on early changes in barrier properties, repair and inflammation in equine colon after ischaemia and reperfusion (I/R). Objectives: To describe the morphology and ultrastructure of the epithelium in equine large colonic mucosa after I/R, and the response of inflammatory cells to injury. Methods: Ischaemia was induced for 1 h followed by 4 h of reperfusion in a 40 cm segment of the pelvic flexure in 6 horses. Mucosal biopsies before and after ischaemia, and after 1, 2 and 4 h of reperfusion were fixed in glutaraldehyde/ paraformaldehyde and osmium tetroxide, and embedded in epon. Morphological and ultrastructural changes were evaluated in toluidine blue-stained semithin sections by light microscopy and in thin sections stained with uranyl acetate/ lead citrate by transmission electron microscopy. Results: Ischaemia caused swelling of epithelial cells and their organelles, opening of tight junctions, detachment from the basement membrane, early apoptosis and single cell necrosis. Autophagy was a prominent feature in epithelial cells after ischaemia. Reperfusion was characterised by apoptosis, epithelial regeneration and restoration of apical cell junctions. Phagocytic-like vacuoles containing cellular debris and bacteria were evident in epithelial cells after reperfusion. Paracellular and subepithelial clefts formed, accompanied by infiltration of neutrophils, lymphocytes and eosinophils into the epithelium. Subepithelial macrophages and luminal neutrophils had increased phagocytic activity. Conclusions: Ischaemia caused ultrastructural damage to the colonic epithelium, but epithelial cells recovered during reperfusion. Potential relevance: Transmission electron microscopy can demonstrate subtle ultrastructural damage to epithelial cells and evidence of recovery after I/R in equine colon.
01 Jan 2011
TL;DR: UVB-induced changes in the corneal ultrastructure were most pronounced in animals fed an ascorbic acid–deficient diet, suggesting that ascorBic acid may play a vital role in protecting the corNEal stroma from the harmful effects of UVB.
TL;DR: The mode of inhibitory action of Zataria multiflora Boiss essential oil (EO) on the fungus, Aspergillus flavus, was studied by colony morphology examination, light microscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM) as mentioned in this paper.
Abstract: The mode of inhibitory action of Zataria multiflora Boiss. essential oil (EO) on the fungus, Aspergillus flavus, was studied by colony morphology examination, light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The EO at concentrations used in this study suppressed the size of the colony as well as sporulation. SEM of mycelia treated with given concentrations of EO showed morphological alterations ranging from loss of turgidity and uniformity of mycelia at low concentrations of EO to evident destruction of the hyphae at higher concentration of EO. Semi-thin sections of mycelia exposed to different concentrations of EO were analysed by light microscopy and revealed that the major change at level as low as 50 ppm of EO was limited to vacuolisation of cytoplasm resulting in cell swelling, while at higher concentrations, detachment of the cell membrane from the cell wall, deformation of mycelia and shedding the cytoplasm from the cell were the main alterations. These damages were well documented by TEM, which showed that the main sites of action of EO were the plasma membrane and cell wall. In conclusion, morphological and structural changes observed in this study may be one of the mechanisms involved in growth inhibition of the fungi and reducing aflatoxin production.
TL;DR: Transmission electron microscopy (TEM) represents a powerful technique for monitoring the effects of various changing parameters or treatments on the development and differentiation of these important organelles within plant cells.
Abstract: Chloroplasts, as well as other, non-photosynthetic types of plastid, are characteristic structures within plant cells. They are relatively large organelles (typically 1-5 μm in diameter), and so can readily be analysed by electron microscopy. Chloroplast structure is remarkably complex, comprising at least six distinct sub-organellar compartments, and is sensitive to developmental changes, environmental effects, and genetic lesions. Transmission electron microscopy (TEM), therefore, represents a powerful technique for monitoring the effects of various changing parameters or treatments on the development and differentiation of these important organelles. We describe a method for the analysis of Arabidopsis plant material by TEM, primarily for the assessment of plastid ultrastructure.
TL;DR: The primitive structure of the spermatozoa suggests that these fertilize the egg by free spawning, probably the ancestral mode of fertilization in early bilaterians, and it is found that the arrangement of organelles in the Xenoturbella sperm shows similarities to a wide range of protostome and deuterostome taxa and does not seem to indicate any particular phylogenetic relationship.
Abstract: Obst, M., Nakano, H., Bourlat, S.J., Thorndyke, M.C., Telford, M.J., Nyengaard, J.R. and Funch, P. 2011. Spermatozoon ultrastructure of Xenoturbella bocki (Westblad 1949). —Acta Zoologica (Stockholm) 92: 109–115.
Here, we report on the sperm ultrastructure of Xenoturbella bocki (Westblad 1949), which we studied for the first time in detail using light, scanning and transmission electron microscopy. The mature spermatozoa are of the bilaterian primitive type, also called aquasperm and develop as uniflagellate sperm consisting of a round head with distinct mitochondria at the base and a 9+2 flagellum of approximately 42 μm in length. The acrosomal complex consists of a small, round electron translucent acrosomal vesicle and a subacrosomal base. There is no separate midpiece, and the mitochondria surround the proximal and distal centriole in the posterior part of the head. The primitive structure of the spermatozoa suggests that these fertilize the egg by free spawning, probably the ancestral mode of fertilization in early bilaterians. When compared to the spermatozoa of other metazoans, we find that the arrangement of organelles in the Xenoturbella sperm shows similarities to a wide range of protostome and deuterostome taxa and does not seem to indicate any particular phylogenetic relationship.
TL;DR: The combination of coating techniques proved superior to the commonly used gold coating to determine fine surface ultrastructure of the motile form ofchromera velia and allowed the diagnosis of this autotrophic protist to be amended.
Journal Article•
TL;DR: ADSCs were differentiated into mature astrocytes with typical characteristics including morphology, ultrastructure, marker protein expression, mature potassium channels and mitotic capacity.
Abstract: Background Adipose-derived stromal cell (ADSC) differentiation into neural cells in vitro is becoming widely studied. However, there are few reports on astrocytes following differentiation, and particularly on maturation and electrophysiology. In this study, we used various methods to determine ADSC-derived astrocyte maturity. Methods Chemical induction with isobutylmethylxanthine (IBMX) was used to differentiate adult ADSCs into astrocytes followed by hematoxylin-eosin (HE) staining to observe morphology and transmission electron microscopy for cellular ultrastructure assessment. Immunofluorescence was used to detect expression of neural stem cell marker nestin as well as glial markers glial fibrillary acidic protein (GFAP) and S-100. In addition, we measured membrane potentials in bis-(1,3-dibarbituric acid) trimethine oxanol-labeled ADSCs and astrocytes by stimulation with a high potassium solution under an inverted fluorescence microscope. Finally, cell cycle distribution was detected by flow cytometry. Results Typical astrocyte morphology was shown by HE staining after 48-hour differentiation. Glial fibril was observed with transmission electron microscopy. GFAP and S-100 were not expressed in the control group, but were expressed within 24-hour differentiation and reached a maximum at day 14 with no change up to day 28. Nestin was weakly expressed in control cells and also reached a maximum at day 14 with the percentage of positive cells constant until day 21 followed by a decrease. Differentiated cell membrane potentials after stimulation with potassium were slightly increased, and then gradually declined over time. There was no significant membrane potential change in the control group. Flow cytometry showed that the percentage of cells in G0/G1 phase was 93% and only 5% in S phase. Conclusion ADSCs were differentiated into mature astrocytes with typical characteristics including morphology, ultrastructure, marker protein expression, mature potassium channels and mitotic capacity.
TL;DR: The results support those in previous light microscopic studies and indicate that the normal life cycle of capsules in both primary and secondary glaucoma include continual outer surface renewal balanced by inner surface degeneration associated with apoptosis and breakdown of tissue matrix components which become more marked over time.
Abstract: UNLABELLED PURPOSE. To report the ultrastructure of cells and extracellular matrix components in Molteno implant capsules examined by scanning and transmission electron microscopy. METHODS Ultrastructural features including cytology, distribution of apoptotic cells, collagens, basement membranes, elastic fibrils, and glycoproteins were examined by scanning and transmission electron microscopy. Findings were correlated with the clinical features of 31 specimens of glaucomatous eyes treated with Molteno implants 0.3 to 14.9 years previously. RESULTS Capsules showed two layers: an outer, moderately cellular vascular layer of normal-appearing cells and collagen and an inner, avascular, hypocellular layer of altered cells and collagen. Cells included fibroblasts, myofibroblasts, and tissue histiocytes that showed features indicating metabolic activity, with swelling, vacuolation, and apoptosis, and the formation of numerous membrane-bound vesicles. These features, together with alteration and disintegration of extracellular matrix, increased with time after surgery. CONCLUSION The results support those in previous light microscopic studies and indicate that the normal life cycle of capsules in both primary and secondary glaucoma include continual outer surface renewal balanced by inner surface degeneration associated with apoptosis and breakdown of tissue matrix components which become more marked over time.
TL;DR: The results suggest that the bonding system is affected by two secretory cell types (granular and columnar cells), both of which are similar in content, synthesis and secretory process butColumnar cells are embedded in a particular cell environment.
Abstract: Water drift and tidal rise make the use of bonding mechanisms beneficial for small benthopelagic or interstitial marine animals. Chemical adhesives for attachment are very common in molluscs; however, only a few cephalopods have glue producing organs. The family Idiosepiidae is characterized by an epithelial adhesive organ (AO) located on the posterior part of the dorsal mantle area. Previous morphological and histological studies described three non-glandular cell types (basal, interstitial and fusiform cells) and three glandular cell types (goblet, columnar and granular cells) containing protein and carbohydrate components. However, these studies provide different information about the nomenclature and characteristics of the cell types. The present ultrastructural analyses and a 3D reconstruction of the AO of Idiosepius pygmaeus and Idiosepius biserialis therefore serve to investigate the cell distribution, the fine structure of the cells and possible interactions between the cells.We found that basal cells form a continuous cell layer along the basal membrane, overlapped by the other epithelial cells. Embedded in microvilli-covered interstitial cells the glandular cells are more or less evenly distributed within the AO. Goblet and granular cells are solitary glandular cells without conspicuous morphological characteristics, whereas the columnar cells are arranged in dense aggregations of 5–15 cells. Each columnar cell is enclosed by a narrow supporting interstitial cell which contains dense longitudinal filament strands. The secretory process of the cells in the aggregation is synchronized. Each columnar cell aggregate bears approximately two ciliated sensory fusiform cells. The fusiform cells are connected to a neuronal network, aligned along the epithelium base.The results suggest that the bonding system is affected by two secretory cell types (granular and columnar cells). Both are similar in content, synthesis and secretory process but columnar cells are embedded in a particular cell environment. It is unclear in what way this arrangement is associated with the function of the AO. The neurons in several parts of the AO point to a neuronal control of the bonding mechanism. Comparisons with the AO cells of other cephalopods provide no indications for a morphological relationship between the adhesive systems.
TL;DR: The morphology and ultrastructure of the alimentary canal in the adult female of the Japanese wax scale, Ceroplastes japonicus Green (Hemiptera: Coccoidea: Coccidae), was investigated using light microscopy, scanning electron microscope and transmission electron microscopy.
TL;DR: The results described the structure of Longicollum pagrosomi and histopathological characters of the intestine of the red sea bream, Pagrus major, infected with acanthocephalans, using the light and electron microscopes.
Abstract: The results described the structure of Longicollum pagrosomi and histopathological characters of the intestine of the red sea bream, Pagrus major, infected with acanthocephalans, using the light and electron microscopes. Among the six samples of P. major, L. pagrosomi was identified in the posterior intestine of five fish samples. Adult L. pagrosomi (total length, 8–27 mm) is divided into the presoma (proboscis, anterior neck, and posterior neck) and metasoma (trunk). The proboscis had vertically arranged hooks (40 μm in length), with ten hooks per row, and the septum was observed between the posterior neck and trunk. The tegument thickness of the proboscis was approximately 15 μm, and it was composed of thin, circular muscle fibers. The outer fibrous membrane was approximately 1 μm, and the connective tissue layer was approximately 35 μm in thickness in the anterior neck. The tegument of the posterior neck enclosed the cephalic ganglion and had longitudinal and vertical muscle fibers, and the tegument thickness was approximately 45 μm. The tegument of the body, which was approximately 1 mm in thickness, was composed primarily of muscle and collagen fibers, and the structure of the tegument was different, depending on the body region. The acanthocephalans had ovaries and oval-shaped eggs with an eggshell (77.5 × 17.1 μm), floating within the body cavity of the trunk. In the infected posterior intestine of P. major, the presoma and the anterior part of the metasoma of L. pagrosomi passed through the intestinal wall and infected the intestinal tissue, perforating the loose connective tissue. In the inflammatory connective tissue, collagen and muscle fibers were fragmented and revealed partial necrosis. Lipid drops and eosinophilic granular cells aggregated in the connective tissue of the tissue capsule. In the vicinity of the acanthocephalan, the mucosal epithelia contained hypertrophied nuclei, and the epithelial layer was collapsed. In an extreme case, the mucosal fold was degenerated because of pressure from the acanthocephalan.
TL;DR: It was concluded that the effect on cellular components was fipronil-specific and changes in cellular ultrastructure seem to be an appropriate ecotoxicological indicator of the insecticide's efficacy.