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Ultrastructural Morphology (ultrastructural + morphology)

Distribution by Scientific Domains

Life Sciences	58%
Medical Sciences	33%

Selected Abstracts

Mitochondrial organization in prepubertal goat oocytes during in vitro maturation and fertilization

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 5 2006
Esther Velilla
Abstract The aim of this study was to evaluate mitochondrial distribution during in vitro maturation (at 0, 15, 20, and 27 hr of IVM) and fertilization of prepubertal goat oocytes compared to mitochondrial distribution of ovulated and in vitro fertilized oocytes from adult goats. Oocytes from prepubertal goats were recovered from a slaughterhouse and were matured in M199 with hormones and serum for 27 hr. Ovulated oocytes were collected from gonadotrophin-treated Murciana goats. Frozen-thawed spermatozoa were selected by centrifugation in Percoll gradient and were capacitated in DMH with 20% steer serum for 1 hr. Ovulated and IVM-oocytes were inseminated in DMH medium with steer serum and calcium lactate for 20 hr. Oocytes and presumptive zygotes were stained with Mitotraker Green FM and observed under a confocal laser scanning microscope. Ultrastructural morphology of oocytes and presumptive zygotes were analyzed by transmission electron microscopy (TEM). Prepubertal goat oocytes at germinal vesicle stage (GV) presented mitochondria localized in the cortical and perinuclear region. IVM-oocytes at metaphase II presented mitochondria peripheral polarized to the region opposite were the metaphase spindle is positioned and within the polar body. Ovulated oocytes presented peripheral mitochondria distribution and mitochondrial aggregation around the MII spindle. At 20 hr post-insemination, mitochondria were distributed around the two synchronous pronuclei (2PN rpar; in zygotes ovulated oocytes whereas in prepubertal 2PN-zygotes mitochondria presented a peripheral polarized distribution. Images by TEM detected that immature prepubertal goat oocytes that are less electrodense and present fewer cristae than in vitro matured prepubertal goat oocytes; these are characterized by being associated to swollen vesicles. Mol. Reprod. Dev. 73: 617,626, 2006 © 2006 Wiley-Liss, Inc. [source]

Characteristics of Rabbit Transgenic Mammary Gland Expressing Recombinant Human Factor VIII

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009
P. Chrenek
Summary The objective of this research was to compare (i) the content of milk protein and recombinant human factor VIII (rhFVIII) in the milk of transgenic and non-transgenic rabbit females at three lactations and (ii) histological structure, ultrastructural morphology and occurrence of apoptosis in rabbit transgenic and non-transgenic mammary gland during third lactation and involution. Significant differences (t0.05) in milk protein content were found between transgenic and non-transgenic at all three lactations. The percentage of apoptotic cells was significantly higher (t0.01) in non-transgenic ones compared with transgenic mammary gland tissues (6.5% versus 2.4%) taken at the involution stage. Morphometrical analysis of histological preparations at the involution stage detected a significantly higher (t0.05) relative volume of lumen in transgenic animals compared with non-transgenic ones (60.00 versus 46.51%). Ultrastructural morphology of the transgenic mammary gland epithelium at the involution stage revealed an increased relative volume of protein globules (t0.05); at the lactation stage, a significantly higher volume of mitochondria (13.8%) compared with the non-transgenic (9.8%) ones was observed. These results, although revealing differences in some parameters of ultrastructure and histology, indicate no harmful effect of the mouse whey acid protein-hFVIII transgene expression on the state of mammary gland of transgenic rabbit females. [source]

Basis of occlusive therapy in psoriasis: correcting defects in permeability barrier and calcium gradient

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2001
Sang Min Hwang MD
Background Although occlusive dressings have great potential in the management of psoriasis vulgaris, the therapeutic mechanism is not completely understood. Occlusion artificially restores and corrects the defective barrier in psoriasis plaques. Additionally, occlusion is know to normalize the epidermal calcium gradients in hyperproliferative murine skin models. Methods To investigate the basis of the therapeutic effect of occlusion on psoriatic plaques, we investigated the ultrastructural morphology of intercorneocyte lipid layers, lamellar bodies, and calcium gradient in chronic plaque-type psoriasis after occlusion with a water vapor-impermeable membrane. The specimens were processed for electron microscopy using: (i) ruthenium tetroxide postfixation; and (ii) ion-capture cytochemistry for calcium localization. Results Occlusion for 7 days resulted in a nearly mature pattern of intercellular multilamellar structures, re-establishment of the near-normal epidermal calcium gradient, and disappearance of calcium precipitates from the stratum corneum interstices. Conclusions The normalization of the permeability barrier and epidermal calcium gradient may play important roles in the therapeutic effects of occlusive dressings in chronic plaque-type psoriasis. [source]

Argemone oil induced cellular damage in the reproductive tissues of transgenic Drosophila melanogaster: Protective role of 70 kDa heat shock protein

JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2003
Indranil Mukhopadhyay
Abstract We explored the reproductive toxicity of argemone oil and its principal alkaloid fraction in transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The toxicity of argemone oil has been attributed to two of its physiologically active benzophenanthridine alkaloids, sanguinarine and dihydrosanguinarine. Freshly eclosed first instar larvae of transgenic Drosophila melanogaster were transferred to different concentrations of argemone oil and its alkaloid fraction contaminated food. Virgin flies that eclosed from the contaminated food were pair-mated to look into the effect on reproduction. The study was further extended by investigating hsp70 expression and tissue damage in larval gonads, genital discs, and reproductive organs of adult fly. Our results showed that argemone oil was more cytotoxic than its principal alkaloid fraction. Moreover, it was the male fly that was more affected compared to its opposite number. The accessory glands of male reproductive system of the fly, which did not express hsp70, exhibited severe damage as evidenced by Trypan blue staining. This prompted us to explore the ultrastructural morphology of the gland, which showed acute signs of necrosis in both the cell types as evident by necrotic nuclei, higher vacuolization, and disorganized endoplasmic reticulum, decrease in the number of Golgi vesicles and disorganized, loosely packed filamentous structures in the lumen of the accessory gland, at the higher concentrations of the adulterant. The study showed the reproductive toxicity of argemone oil and its alkaloid fraction in transgenic Drosophila melanogaster and further confirmed the cytoprotective role of hsp70. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:223,234, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10082. [source]

Ultrastructure of the gingiva in cardiac patients treated with or without calcium channel blockers

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2003
P. Bullon
Abstract Objectives: In the last few years, several studies have suggested that periodontal diseases are related to the development of atherosclerosis and its complications. Our objective was to study the ultrastructural morphology of the gingiva from cardiac patients, some of whom were treated and some not with calcium channel blockers compared to a control group. Material and Methods: Fifty-five patients were studied and grouped in the following way: (a) healthy group (HG) (n=12) healthy patients with at least two pockets between 3 and 5 mm; (b) cardiac group (CG) (n=12) patients with cardiac disease untreated with calcium channel blockers; (c) diltiazem group (DG) (n=13) cardiac patients treated with diltiazem; (d) nifedipine group (NG) (n=18) cardiac patients treated with nifedipine. Results: Ultrastructural studies in the CG showed inflammatory cells, collagen fibers disruption and a more extended morphologically compromised fibroblast mitochondria. Morphometric studies in CG showed mitochondria that were impaired in number but increased in volume, suggesting metabolic cell suffering. In DG and NG, morphometric data were similar to HG. The presence of myofibroblasts and collagen neosynthesis was detected in DG and NG. Conclusions: Our data showed differences in the ultrastructure of the gingival fibroblasts between the studied groups; the DG and NG showed features that could be interpreted as an attempt to restore the cellular metabolic function. Zusammenfassung Ziele: In den letzten Jahren haben einige Studien darauf hingewiesen, dass parodontale Erkrankungen zur Entwicklung von Arteriosklerose und deren Komplikationen in Beziehung stehen. Unser Ziel war das Studium der gingivalen ultrastrukturellen Morphologie von herzkranken Patienten, von denen einige mit Kalzium-Kanal-Blockern und andere ohne diese Medikamente behandelt wurden, und mit Kontrollen zu vergleichen. Material und Methoden: 55 Patienten wurden untersucht und in eine der folgenden Gruppen eingeteilt: a, gesunde Gruppe (HG) (n=12): gesunde Patienten mit mindestens 2 Taschen zwischen 3 und 5 mm, b, herzkranke Gruppe (CG) (n=12): Patienten mit Herzerkrankung und nicht mit Kalzium-Kanal-Blockern behandelt, c, Diltiazem Gruppe (DG) (n=13): Herzkranke Patienten, die mit Diltiazem behandelt wurden, d, Nifedipin Gruppe (NG) (n=18): Herzkranke Patienten, die mit Nifedipin behandelt wurden. Ergebnisse: Die Ultrastruktur bei CG zeigte Entzündungszellen, zerrissene Kollagenfasern und stärker ausgedehnte morphologisch gefährdete Fibroblastenmitochondrien. Morphometrische Studien bei CG zeigten Mitochondrien, die in der Anzahl beeinträchtigt waren, aber im Volumen zugenommen hatten, was auf einen gestörten Zellstoffwechsel deutet. Bei DG und NG waren die morphometrischen Daten ähnlich zu HG. Die Präsenz von Myofibroblasten und Kollagensynthese wurde in DG und NG entdeckt. Schlussfolgerung: Unsere Daten zeigten Differenzen in der Ultrastruktur der gingivalen Fibroblasten zwischen den untersuchten Gruppen. DG und NG zeigten Eigenschaften, die als Versuch zur Restauration der zellulären Stoffwechselfunktion gedeutet werden könnten. Résumé Objectifs: Lors des dernières années, plusieurs études ont suggéré que les maladies parodontales sont liées au développement de l'athérosclérose et de ses conséquences. Notre objectif est d'étudier la morphologie ultrastructurale de la gencive de patients cardiaques traités et non traités par des bloqueurs des flux de calcium comparée à un groupe contrôle. Matériel et méthodes: 55 patients furent étudiés et groupés de la façon suivante: (a) groupe sain (HG) (n=12), patients sains avec au moins 2 poches entre 3 et 5 mm (b) groupe cardiaque(CG) (n=12) patients ayant une maladie cardiaque non traitée par des bloqueurs des flux de calcium (c) groupe diltiazem (DG) (n=13) patients cardiaques traits par diltiazem; (d) groupe nifedipine (NG) (n=18 patients cardiaques traits par nifedipine). Résultats: Des études ultrastructurale du groupe CG montraient des cellules inflammatoires, des interruptions des fibres de collagènes, et un nombre plus important de mitochondries des fibroblastes morphologiquement compromises. Les études morphométriques du groupe CG montraient des mitochondries altérées en nombre mais au volume augmenté ce qui suggérait une souffrance métabolique cellulaire. Dans les groupes DG et NG, les données morphométriques étaient similaires à celles du groupe HG. La présence de myofibroblastes et d'une néo-synthèse de collagène étaient détectées dans les groupes DG et NG. Conclusions: Nos données montrent des différences de l'ultrastructure des fibroblastes gingivaux entre les groupes étudiés, les groupes DG et NG présentant des caractéristiques qui peuvent être interprétées comme une tentative de restauration de la fonction métabolique cellulaire. [source]

Effect of amyloid ,-peptide on permeability transition pore: A comparative study

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2002
Paula I. Moreira
Abstract A potentially central factor in neurodegeneration is the permeability transition pore (PTP). Because of the tissue-specific differences in pore properties, we directly compared isolated brain and liver mitochondria responses to the neurotoxic A, peptides. For this purpose, the following parameters were examined: mitochondrial membrane potential (,,m), respiration, swelling, ultrastructural morphology, and content of cytochrome c. Both peptides, A,25,35 (50 ,M) and A,1,40 (2 ,M), had a similar toxicity, exacerbating the effects of Ca2+, although, per se, they did not induce (PTP). In liver mitochondria, A, led to a drop in ,,m and potentiated matrix swelling and disruption induced by Ca2+. In contrast, brain mitochondria, exposed to the same conditions, demonstrated a higher capacity to accumulate Ca2+ before the ,,m drop and a slight increase of mitochondrial swelling compared with liver mitochondria. Furthermore, mitochondrial respiratory state 3 was depressed in the presence of A,, whereas state 4 was unaltered, resulting in an uncoupling of respiration. In both types of mitochondria, A, did not affect the content of cytochrome c. The ,,m drop was reversed when Ca2+ was removed by EGTA or when ADP plus oligomycin was present. Pretreatment with cyclosporin A or ADP plus oligomycin prevented the deleterious effects promoted by A, and/or Ca2+. It can be concluded that brain and liver mitochondria show a different susceptibility to the deleterious effect of A, peptide, brain mitochondria being more resistant to the potentiation by A, of Ca2+ -induced PTP. © 2002 Wiley-Liss, Inc. [source]

Ultrastructural and immunocytochemical analyses of opioid treatment effects on PC3 prostatic cancer cells

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2004
Beatrice Baldelli
Abstract Some opioid peptides are able to inhibit the growth of human prostatic cancer cells; in particular, the [D-Ala2,D-Leu5] enkephalin (DADLE) reduces PC3 cell growth. In order to understand how DADLE decreases cell proliferation, we investigated, by electron microscopy, its effects on PC3 cellular components. PC3 cells were incubated with DADLE and processed for both ultrastructural morphology and immunoelectron microscopy. Some cells were incubated with BrU to determine the transcriptional rate. BrU and DADLE molecules were detected by immunogold techniques and the labeling was quantitatively evaluated. Modifications of some cytoplasmic and nuclear components were observed in DADLE-treated cells. Moreover, treated cells incorporated lower amounts of BrU than control cells. DADLE molecules were located in the cytoplasm and in the nucleus, especially on mRNA transcription and early splicing sites. Our data suggest that DADLE is able to slow down the synthetic activity of PC3 cells, perhaps interfering with nuclear functions. Microsc. Res. Tech. 64:243,249, 2004. © 2004 Wiley-Liss, Inc. [source]

Complex phylogeographic patterns in the freshwater alga Synura provide new insights into ubiquity vs. endemism in microbial eukaryotes

MOLECULAR ECOLOGY, Issue 19 2010
SUNG MIN BOO
Abstract The global distribution, abundance, and diversity of microscopic freshwater algae demonstrate an ability to overcome significant barriers such as dry land and oceans by exploiting a range of biotic and abiotic colonization vectors. If these vectors are considered unlimited and colonization occurs in proportion to population size, then globally ubiquitous distributions are predicted to arise. This model contrasts with observations that many freshwater microalgal taxa possess true biogeographies. Here, using a concatenated multigene data set, we study the phylogeography of the freshwater heterokont alga Synura petersenii sensu lato. Our results suggest that this Synura morphotaxon contains both cosmopolitan and regionally endemic cryptic species, co-occurring in some cases, and masked by a common ultrastructural morphology. Phylogenies based on both proteins (seven protein-coding plastid and mitochondrial genes) and DNA (nine genes including ITS and 18S rDNA) reveal pronounced biogeographic delineations within phylotypes of this cryptic species complex while retaining one clade that is globally distributed. Relaxed molecular clock calculations, constrained by fossil records, suggest that the genus Synura is considerably older than currently proposed. The availability of tectonically relevant geological time (107,108 years) has enabled the development of the observed, complex biogeographic patterns. Our comprehensive analysis of freshwater algal biogeography suggests that neither ubiquity nor endemism wholly explains global patterns of microbial eukaryote distribution and that processes of dispersal remain poorly understood. [source]

A New Species of Myxozoa, Henneguya rondoni n. sp. (Myxozoa), from the Peripheral Nervous System of the Amazonian Fish, Gymnorhamphichthys rondoni (Teleostei)

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 3 2008
CARLOS AZEVEDO
ABSTRACT. Henneguya rondoni n. sp. found in the peripheral lateral nerves located below the two lateral lines of the fish Gymnorhamphichthys rondoni (Teleostei, Rhamphichthyidae) from the Amazon river is described using light and electron microscopy. Spherical to ellipsoid cysts measuring up to 110 ,m in length contained only immature and mature spores located in close contact with the myelin sheaths of the nervous fibres. Ellipsoidal spores measured 17.7 (16.9,18.1)-,m long, 3.6 (3.0,3.9)-,m wide, and 2.5 (2.2,2.8)-,m (n=25) thick. The spore body measuring 7.0 (6.8,7.3)-,m long was formed by two equal symmetric valves, each with an equal tapering tail 10.7 (10.3,11.0) ,m in length. The tails were composed of an internal dense material surrounded by an external homogeneous sheath of hyaline substance. The valves surrounded two equal pyriform polar capsules measuring 2.5 (2.2,2.8)-,m long and 0.85 (0.79,0.88)-,m (n=25) wide and a binucleated sporoplasm cell containing globular sporoplasmosomes 0.38 (0.33,0.42) ,m (n=25) in diam. with an internal eccentric dense structure with half-crescent section. Each polar capsule contains an anisofilar polar filament with 6,7 turns obliquely to the long axis. The matrix of the polar capsule was dense and the wall filled with a hyaline substance. The spores differed from those of previously described species. Based on the ultrastructural morphology of the spore and specificity to the host species, we propose a new species name H. rondoni n. sp. [source]

Not the most basal eukaryotes: challenges and pitfalls affecting the placement of Giardia and Trichomonas

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2005
GISELLE WALKER
Diplomonads (including Giardia) and parabasalids (including Trichomonas) have traditionally been seen as the deepest-branching eukaryotes, on the evidence of apparently simple ultrastructural morphology, and small subunit ribosomal RNA trees. However, this position does not appear to be well supported, especially in the light of the discoveries of apparent mitochondrial remnants in Giardia and Trichomonas. We systematically re-analysed protein data, and show here that their traditional placement may be due to a combination of factors acting on data sets (narrow taxon sampling) and on genes (rate heterogeneity and compositional heterogeneity, mutational saturation). Our data found no consistent support for either Giardia or Trichomonas being basal eukaryotes. [source]

Characteristics of Rabbit Transgenic Mammary Gland Expressing Recombinant Human Factor VIII

Evidence from immunoneutralization and antisense studies that the inhibitory actions of glucocorticoids on growth hormone release in vitro require annexin 1 (lipocortin 1)

BRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2000
A D Taylor
Our previous studies have identified a role for annexin 1 as a mediator of glucocorticoid action in the neuroendocrine system. The present study centred on growth hormone (GH) and exploited antisense and immunoneutralization strategies to examine in vitro the potential role of annexin 1 in effecting the regulatory actions of glucocorticoids on the secretion of this pituitary hormone. Rat anterior pituitary tissue responded in vitro to growth hormone releasing hormone, forskolin, 8-Bromo-cyclic adenosine 3,5,-monophosphate (8-Br-cyclic AMP) and an L-Ca2+ channel opener (BAY K8644) with concentration-dependent increases GH release which were readily inhibited by corticosterone and dexamethasone. The inhibitory actions of the steroids on GH release elicited by the above secretagogues were effectively reversed by an annexin 1 antisense oligodeoxynucleotide (ODN), but not by control (sense or scrambled) ODNs, as also were the glucocorticoid-induced increases in annexin 1. Similarly, a specific anti-annexin 1 monoclonal antibody quenched the corticosterone-induced suppression of secretagogue-evoked GH release while an isotype matched control antibody was without effect. Transmission electron micrographs showed that the integrity and ultrastructural morphology of the pituitary cells were well preserved at the end of the incubation and unaffected by exposure to the ODNs, antibodies, steroids or secretagogues. The results provide novel evidence for a role for annexin 1 as a mediator of the inhibitory actions of glucocorticoids on the secretion of GH by the anterior pituitary gland and suggest that its actions are effected at a point distal to the formation of cyclic AMP and Ca2+ entry. British Journal of Pharmacology (2000) 131, 1309,1316; doi:10.1038/sj.bjp.0703694 [source]